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android_kernel_xiaomi_sm8350/arch/ia64/kernel/perfmon.c
stephane eranian 83014699b0 [IA64] perfmon: fix async exit bug 
Move the cleanup of the async queue to the close callback from the flush
callback. This avoids losing asynchronous overflow notifications when
the file descriptor is shared by multiple processes and one terminates.

Signed-off-by: Stephane Eranian <eranian@gmail.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-11 15:24:13 -07:00

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/*
* This file implements the perfmon-2 subsystem which is used
* to program the IA-64 Performance Monitoring Unit (PMU).
*
* The initial version of perfmon.c was written by
* Ganesh Venkitachalam, IBM Corp.
*
* Then it was modified for perfmon-1.x by Stephane Eranian and
* David Mosberger, Hewlett Packard Co.
*
* Version Perfmon-2.x is a rewrite of perfmon-1.x
* by Stephane Eranian, Hewlett Packard Co.
*
* Copyright (C) 1999-2005 Hewlett Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* More information about perfmon available at:
* http://www.hpl.hp.com/research/linux/perfmon
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/sysctl.h>
#include <linux/list.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/vfs.h>
#include <linux/smp.h>
#include <linux/pagemap.h>
#include <linux/mount.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/rcupdate.h>
#include <linux/completion.h>
#include <asm/errno.h>
#include <asm/intrinsics.h>
#include <asm/page.h>
#include <asm/perfmon.h>
#include <asm/processor.h>
#include <asm/signal.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#ifdef CONFIG_PERFMON
/*
* perfmon context state
*/
#define PFM_CTX_UNLOADED 1 /* context is not loaded onto any task */
#define PFM_CTX_LOADED 2 /* context is loaded onto a task */
#define PFM_CTX_MASKED 3 /* context is loaded but monitoring is masked due to overflow */
#define PFM_CTX_ZOMBIE 4 /* owner of the context is closing it */
#define PFM_INVALID_ACTIVATION (~0UL)
#define PFM_NUM_PMC_REGS 64 /* PMC save area for ctxsw */
#define PFM_NUM_PMD_REGS 64 /* PMD save area for ctxsw */
/*
* depth of message queue
*/
#define PFM_MAX_MSGS 32
#define PFM_CTXQ_EMPTY(g) ((g)->ctx_msgq_head == (g)->ctx_msgq_tail)
/*
* type of a PMU register (bitmask).
* bitmask structure:
* bit0 : register implemented
* bit1 : end marker
* bit2-3 : reserved
* bit4 : pmc has pmc.pm
* bit5 : pmc controls a counter (has pmc.oi), pmd is used as counter
* bit6-7 : register type
* bit8-31: reserved
*/
#define PFM_REG_NOTIMPL 0x0 /* not implemented at all */
#define PFM_REG_IMPL 0x1 /* register implemented */
#define PFM_REG_END 0x2 /* end marker */
#define PFM_REG_MONITOR (0x1<<4|PFM_REG_IMPL) /* a PMC with a pmc.pm field only */
#define PFM_REG_COUNTING (0x2<<4|PFM_REG_MONITOR) /* a monitor + pmc.oi+ PMD used as a counter */
#define PFM_REG_CONTROL (0x4<<4|PFM_REG_IMPL) /* PMU control register */
#define PFM_REG_CONFIG (0x8<<4|PFM_REG_IMPL) /* configuration register */
#define PFM_REG_BUFFER (0xc<<4|PFM_REG_IMPL) /* PMD used as buffer */
#define PMC_IS_LAST(i) (pmu_conf->pmc_desc[i].type & PFM_REG_END)
#define PMD_IS_LAST(i) (pmu_conf->pmd_desc[i].type & PFM_REG_END)
#define PMC_OVFL_NOTIFY(ctx, i) ((ctx)->ctx_pmds[i].flags & PFM_REGFL_OVFL_NOTIFY)
/* i assumed unsigned */
#define PMC_IS_IMPL(i) (i< PMU_MAX_PMCS && (pmu_conf->pmc_desc[i].type & PFM_REG_IMPL))
#define PMD_IS_IMPL(i) (i< PMU_MAX_PMDS && (pmu_conf->pmd_desc[i].type & PFM_REG_IMPL))
/* XXX: these assume that register i is implemented */
#define PMD_IS_COUNTING(i) ((pmu_conf->pmd_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
#define PMC_IS_COUNTING(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_COUNTING) == PFM_REG_COUNTING)
#define PMC_IS_MONITOR(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_MONITOR) == PFM_REG_MONITOR)
#define PMC_IS_CONTROL(i) ((pmu_conf->pmc_desc[i].type & PFM_REG_CONTROL) == PFM_REG_CONTROL)
#define PMC_DFL_VAL(i) pmu_conf->pmc_desc[i].default_value
#define PMC_RSVD_MASK(i) pmu_conf->pmc_desc[i].reserved_mask
#define PMD_PMD_DEP(i) pmu_conf->pmd_desc[i].dep_pmd[0]
#define PMC_PMD_DEP(i) pmu_conf->pmc_desc[i].dep_pmd[0]
#define PFM_NUM_IBRS IA64_NUM_DBG_REGS
#define PFM_NUM_DBRS IA64_NUM_DBG_REGS
#define CTX_OVFL_NOBLOCK(c) ((c)->ctx_fl_block == 0)
#define CTX_HAS_SMPL(c) ((c)->ctx_fl_is_sampling)
#define PFM_CTX_TASK(h) (h)->ctx_task
#define PMU_PMC_OI 5 /* position of pmc.oi bit */
/* XXX: does not support more than 64 PMDs */
#define CTX_USED_PMD(ctx, mask) (ctx)->ctx_used_pmds[0] |= (mask)
#define CTX_IS_USED_PMD(ctx, c) (((ctx)->ctx_used_pmds[0] & (1UL << (c))) != 0UL)
#define CTX_USED_MONITOR(ctx, mask) (ctx)->ctx_used_monitors[0] |= (mask)
#define CTX_USED_IBR(ctx,n) (ctx)->ctx_used_ibrs[(n)>>6] |= 1UL<< ((n) % 64)
#define CTX_USED_DBR(ctx,n) (ctx)->ctx_used_dbrs[(n)>>6] |= 1UL<< ((n) % 64)
#define CTX_USES_DBREGS(ctx) (((pfm_context_t *)(ctx))->ctx_fl_using_dbreg==1)
#define PFM_CODE_RR 0 /* requesting code range restriction */
#define PFM_DATA_RR 1 /* requestion data range restriction */
#define PFM_CPUINFO_CLEAR(v) pfm_get_cpu_var(pfm_syst_info) &= ~(v)
#define PFM_CPUINFO_SET(v) pfm_get_cpu_var(pfm_syst_info) |= (v)
#define PFM_CPUINFO_GET() pfm_get_cpu_var(pfm_syst_info)
#define RDEP(x) (1UL<<(x))
/*
* context protection macros
* in SMP:
* - we need to protect against CPU concurrency (spin_lock)
* - we need to protect against PMU overflow interrupts (local_irq_disable)
* in UP:
* - we need to protect against PMU overflow interrupts (local_irq_disable)
*
* spin_lock_irqsave()/spin_unlock_irqrestore():
* in SMP: local_irq_disable + spin_lock
* in UP : local_irq_disable
*
* spin_lock()/spin_lock():
* in UP : removed automatically
* in SMP: protect against context accesses from other CPU. interrupts
* are not masked. This is useful for the PMU interrupt handler
* because we know we will not get PMU concurrency in that code.
*/
#define PROTECT_CTX(c, f) \
do { \
DPRINT(("spinlock_irq_save ctx %p by [%d]\n", c, task_pid_nr(current))); \
spin_lock_irqsave(&(c)->ctx_lock, f); \
DPRINT(("spinlocked ctx %p by [%d]\n", c, task_pid_nr(current))); \
} while(0)
#define UNPROTECT_CTX(c, f) \
do { \
DPRINT(("spinlock_irq_restore ctx %p by [%d]\n", c, task_pid_nr(current))); \
spin_unlock_irqrestore(&(c)->ctx_lock, f); \
} while(0)
#define PROTECT_CTX_NOPRINT(c, f) \
do { \
spin_lock_irqsave(&(c)->ctx_lock, f); \
} while(0)
#define UNPROTECT_CTX_NOPRINT(c, f) \
do { \
spin_unlock_irqrestore(&(c)->ctx_lock, f); \
} while(0)
#define PROTECT_CTX_NOIRQ(c) \
do { \
spin_lock(&(c)->ctx_lock); \
} while(0)
#define UNPROTECT_CTX_NOIRQ(c) \
do { \
spin_unlock(&(c)->ctx_lock); \
} while(0)
#ifdef CONFIG_SMP
#define GET_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)
#define INC_ACTIVATION() pfm_get_cpu_var(pmu_activation_number)++
#define SET_ACTIVATION(c) (c)->ctx_last_activation = GET_ACTIVATION()
#else /* !CONFIG_SMP */
#define SET_ACTIVATION(t) do {} while(0)
#define GET_ACTIVATION(t) do {} while(0)
#define INC_ACTIVATION(t) do {} while(0)
#endif /* CONFIG_SMP */
#define SET_PMU_OWNER(t, c) do { pfm_get_cpu_var(pmu_owner) = (t); pfm_get_cpu_var(pmu_ctx) = (c); } while(0)
#define GET_PMU_OWNER() pfm_get_cpu_var(pmu_owner)
#define GET_PMU_CTX() pfm_get_cpu_var(pmu_ctx)
#define LOCK_PFS(g) spin_lock_irqsave(&pfm_sessions.pfs_lock, g)
#define UNLOCK_PFS(g) spin_unlock_irqrestore(&pfm_sessions.pfs_lock, g)
#define PFM_REG_RETFLAG_SET(flags, val) do { flags &= ~PFM_REG_RETFL_MASK; flags |= (val); } while(0)
/*
* cmp0 must be the value of pmc0
*/
#define PMC0_HAS_OVFL(cmp0) (cmp0 & ~0x1UL)
#define PFMFS_MAGIC 0xa0b4d889
/*
* debugging
*/
#define PFM_DEBUGGING 1
#ifdef PFM_DEBUGGING
#define DPRINT(a) \
do { \
if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
} while (0)
#define DPRINT_ovfl(a) \
do { \
if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d [%d] ", __func__, __LINE__, smp_processor_id(), task_pid_nr(current)); printk a; } \
} while (0)
#endif
/*
* 64-bit software counter structure
*
* the next_reset_type is applied to the next call to pfm_reset_regs()
*/
typedef struct {
unsigned long val; /* virtual 64bit counter value */
unsigned long lval; /* last reset value */
unsigned long long_reset; /* reset value on sampling overflow */
unsigned long short_reset; /* reset value on overflow */
unsigned long reset_pmds[4]; /* which other pmds to reset when this counter overflows */
unsigned long smpl_pmds[4]; /* which pmds are accessed when counter overflow */
unsigned long seed; /* seed for random-number generator */
unsigned long mask; /* mask for random-number generator */
unsigned int flags; /* notify/do not notify */
unsigned long eventid; /* overflow event identifier */
} pfm_counter_t;
/*
* context flags
*/
typedef struct {
unsigned int block:1; /* when 1, task will blocked on user notifications */
unsigned int system:1; /* do system wide monitoring */
unsigned int using_dbreg:1; /* using range restrictions (debug registers) */
unsigned int is_sampling:1; /* true if using a custom format */
unsigned int excl_idle:1; /* exclude idle task in system wide session */
unsigned int going_zombie:1; /* context is zombie (MASKED+blocking) */
unsigned int trap_reason:2; /* reason for going into pfm_handle_work() */
unsigned int no_msg:1; /* no message sent on overflow */
unsigned int can_restart:1; /* allowed to issue a PFM_RESTART */
unsigned int reserved:22;
} pfm_context_flags_t;
#define PFM_TRAP_REASON_NONE 0x0 /* default value */
#define PFM_TRAP_REASON_BLOCK 0x1 /* we need to block on overflow */
#define PFM_TRAP_REASON_RESET 0x2 /* we need to reset PMDs */
/*
* perfmon context: encapsulates all the state of a monitoring session
*/
typedef struct pfm_context {
spinlock_t ctx_lock; /* context protection */
pfm_context_flags_t ctx_flags; /* bitmask of flags (block reason incl.) */
unsigned int ctx_state; /* state: active/inactive (no bitfield) */
struct task_struct *ctx_task; /* task to which context is attached */
unsigned long ctx_ovfl_regs[4]; /* which registers overflowed (notification) */
struct completion ctx_restart_done; /* use for blocking notification mode */
unsigned long ctx_used_pmds[4]; /* bitmask of PMD used */
unsigned long ctx_all_pmds[4]; /* bitmask of all accessible PMDs */
unsigned long ctx_reload_pmds[4]; /* bitmask of force reload PMD on ctxsw in */
unsigned long ctx_all_pmcs[4]; /* bitmask of all accessible PMCs */
unsigned long ctx_reload_pmcs[4]; /* bitmask of force reload PMC on ctxsw in */
unsigned long ctx_used_monitors[4]; /* bitmask of monitor PMC being used */
unsigned long ctx_pmcs[PFM_NUM_PMC_REGS]; /* saved copies of PMC values */
unsigned int ctx_used_ibrs[1]; /* bitmask of used IBR (speedup ctxsw in) */
unsigned int ctx_used_dbrs[1]; /* bitmask of used DBR (speedup ctxsw in) */
unsigned long ctx_dbrs[IA64_NUM_DBG_REGS]; /* DBR values (cache) when not loaded */
unsigned long ctx_ibrs[IA64_NUM_DBG_REGS]; /* IBR values (cache) when not loaded */
pfm_counter_t ctx_pmds[PFM_NUM_PMD_REGS]; /* software state for PMDS */
unsigned long th_pmcs[PFM_NUM_PMC_REGS]; /* PMC thread save state */
unsigned long th_pmds[PFM_NUM_PMD_REGS]; /* PMD thread save state */
u64 ctx_saved_psr_up; /* only contains psr.up value */
unsigned long ctx_last_activation; /* context last activation number for last_cpu */
unsigned int ctx_last_cpu; /* CPU id of current or last CPU used (SMP only) */
unsigned int ctx_cpu; /* cpu to which perfmon is applied (system wide) */
int ctx_fd; /* file descriptor used my this context */
pfm_ovfl_arg_t ctx_ovfl_arg; /* argument to custom buffer format handler */
pfm_buffer_fmt_t *ctx_buf_fmt; /* buffer format callbacks */
void *ctx_smpl_hdr; /* points to sampling buffer header kernel vaddr */
unsigned long ctx_smpl_size; /* size of sampling buffer */
void *ctx_smpl_vaddr; /* user level virtual address of smpl buffer */
wait_queue_head_t ctx_msgq_wait;
pfm_msg_t ctx_msgq[PFM_MAX_MSGS];
int ctx_msgq_head;
int ctx_msgq_tail;
struct fasync_struct *ctx_async_queue;
wait_queue_head_t ctx_zombieq; /* termination cleanup wait queue */
} pfm_context_t;
/*
* magic number used to verify that structure is really
* a perfmon context
*/
#define PFM_IS_FILE(f) ((f)->f_op == &pfm_file_ops)
#define PFM_GET_CTX(t) ((pfm_context_t *)(t)->thread.pfm_context)
#ifdef CONFIG_SMP
#define SET_LAST_CPU(ctx, v) (ctx)->ctx_last_cpu = (v)
#define GET_LAST_CPU(ctx) (ctx)->ctx_last_cpu
#else
#define SET_LAST_CPU(ctx, v) do {} while(0)
#define GET_LAST_CPU(ctx) do {} while(0)
#endif
#define ctx_fl_block ctx_flags.block
#define ctx_fl_system ctx_flags.system
#define ctx_fl_using_dbreg ctx_flags.using_dbreg
#define ctx_fl_is_sampling ctx_flags.is_sampling
#define ctx_fl_excl_idle ctx_flags.excl_idle
#define ctx_fl_going_zombie ctx_flags.going_zombie
#define ctx_fl_trap_reason ctx_flags.trap_reason
#define ctx_fl_no_msg ctx_flags.no_msg
#define ctx_fl_can_restart ctx_flags.can_restart
#define PFM_SET_WORK_PENDING(t, v) do { (t)->thread.pfm_needs_checking = v; } while(0);
#define PFM_GET_WORK_PENDING(t) (t)->thread.pfm_needs_checking
/*
* global information about all sessions
* mostly used to synchronize between system wide and per-process
*/
typedef struct {
spinlock_t pfs_lock; /* lock the structure */
unsigned int pfs_task_sessions; /* number of per task sessions */
unsigned int pfs_sys_sessions; /* number of per system wide sessions */
unsigned int pfs_sys_use_dbregs; /* incremented when a system wide session uses debug regs */
unsigned int pfs_ptrace_use_dbregs; /* incremented when a process uses debug regs */
struct task_struct *pfs_sys_session[NR_CPUS]; /* point to task owning a system-wide session */
} pfm_session_t;
/*
* information about a PMC or PMD.
* dep_pmd[]: a bitmask of dependent PMD registers
* dep_pmc[]: a bitmask of dependent PMC registers
*/
typedef int (*pfm_reg_check_t)(struct task_struct *task, pfm_context_t *ctx, unsigned int cnum, unsigned long *val, struct pt_regs *regs);
typedef struct {
unsigned int type;
int pm_pos;
unsigned long default_value; /* power-on default value */
unsigned long reserved_mask; /* bitmask of reserved bits */
pfm_reg_check_t read_check;
pfm_reg_check_t write_check;
unsigned long dep_pmd[4];
unsigned long dep_pmc[4];
} pfm_reg_desc_t;
/* assume cnum is a valid monitor */
#define PMC_PM(cnum, val) (((val) >> (pmu_conf->pmc_desc[cnum].pm_pos)) & 0x1)
/*
* This structure is initialized at boot time and contains
* a description of the PMU main characteristics.
*
* If the probe function is defined, detection is based
* on its return value:
* - 0 means recognized PMU
* - anything else means not supported
* When the probe function is not defined, then the pmu_family field
* is used and it must match the host CPU family such that:
* - cpu->family & config->pmu_family != 0
*/
typedef struct {
unsigned long ovfl_val; /* overflow value for counters */
pfm_reg_desc_t *pmc_desc; /* detailed PMC register dependencies descriptions */
pfm_reg_desc_t *pmd_desc; /* detailed PMD register dependencies descriptions */
unsigned int num_pmcs; /* number of PMCS: computed at init time */
unsigned int num_pmds; /* number of PMDS: computed at init time */
unsigned long impl_pmcs[4]; /* bitmask of implemented PMCS */
unsigned long impl_pmds[4]; /* bitmask of implemented PMDS */
char *pmu_name; /* PMU family name */
unsigned int pmu_family; /* cpuid family pattern used to identify pmu */
unsigned int flags; /* pmu specific flags */
unsigned int num_ibrs; /* number of IBRS: computed at init time */
unsigned int num_dbrs; /* number of DBRS: computed at init time */
unsigned int num_counters; /* PMC/PMD counting pairs : computed at init time */
int (*probe)(void); /* customized probe routine */
unsigned int use_rr_dbregs:1; /* set if debug registers used for range restriction */
} pmu_config_t;
/*
* PMU specific flags
*/
#define PFM_PMU_IRQ_RESEND 1 /* PMU needs explicit IRQ resend */
/*
* debug register related type definitions
*/
typedef struct {
unsigned long ibr_mask:56;
unsigned long ibr_plm:4;
unsigned long ibr_ig:3;
unsigned long ibr_x:1;
} ibr_mask_reg_t;
typedef struct {
unsigned long dbr_mask:56;
unsigned long dbr_plm:4;
unsigned long dbr_ig:2;
unsigned long dbr_w:1;
unsigned long dbr_r:1;
} dbr_mask_reg_t;
typedef union {
unsigned long val;
ibr_mask_reg_t ibr;
dbr_mask_reg_t dbr;
} dbreg_t;
/*
* perfmon command descriptions
*/
typedef struct {
int (*cmd_func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
char *cmd_name;
int cmd_flags;
unsigned int cmd_narg;
size_t cmd_argsize;
int (*cmd_getsize)(void *arg, size_t *sz);
} pfm_cmd_desc_t;
#define PFM_CMD_FD 0x01 /* command requires a file descriptor */
#define PFM_CMD_ARG_READ 0x02 /* command must read argument(s) */
#define PFM_CMD_ARG_RW 0x04 /* command must read/write argument(s) */
#define PFM_CMD_STOP 0x08 /* command does not work on zombie context */
#define PFM_CMD_NAME(cmd) pfm_cmd_tab[(cmd)].cmd_name
#define PFM_CMD_READ_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_READ)
#define PFM_CMD_RW_ARG(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_ARG_RW)
#define PFM_CMD_USE_FD(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_FD)
#define PFM_CMD_STOPPED(cmd) (pfm_cmd_tab[(cmd)].cmd_flags & PFM_CMD_STOP)
#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
typedef struct {
unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
unsigned long pfm_ovfl_intr_count; /* keep track of ovfl interrupts */
unsigned long pfm_ovfl_intr_cycles; /* cycles spent processing ovfl interrupts */
unsigned long pfm_ovfl_intr_cycles_min; /* min cycles spent processing ovfl interrupts */
unsigned long pfm_ovfl_intr_cycles_max; /* max cycles spent processing ovfl interrupts */
unsigned long pfm_smpl_handler_calls;
unsigned long pfm_smpl_handler_cycles;
char pad[SMP_CACHE_BYTES] ____cacheline_aligned;
} pfm_stats_t;
/*
* perfmon internal variables
*/
static pfm_stats_t pfm_stats[NR_CPUS];
static pfm_session_t pfm_sessions; /* global sessions information */
static DEFINE_SPINLOCK(pfm_alt_install_check);
static pfm_intr_handler_desc_t *pfm_alt_intr_handler;
static struct proc_dir_entry *perfmon_dir;
static pfm_uuid_t pfm_null_uuid = {0,};
static spinlock_t pfm_buffer_fmt_lock;
static LIST_HEAD(pfm_buffer_fmt_list);
static pmu_config_t *pmu_conf;
/* sysctl() controls */
pfm_sysctl_t pfm_sysctl;
EXPORT_SYMBOL(pfm_sysctl);
static ctl_table pfm_ctl_table[]={
{
.ctl_name = CTL_UNNUMBERED,
.procname = "debug",
.data = &pfm_sysctl.debug,
.maxlen = sizeof(int),
.mode = 0666,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "debug_ovfl",
.data = &pfm_sysctl.debug_ovfl,
.maxlen = sizeof(int),
.mode = 0666,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "fastctxsw",
.data = &pfm_sysctl.fastctxsw,
.maxlen = sizeof(int),
.mode = 0600,
.proc_handler = &proc_dointvec,
},
{
.ctl_name = CTL_UNNUMBERED,
.procname = "expert_mode",
.data = &pfm_sysctl.expert_mode,
.maxlen = sizeof(int),
.mode = 0600,
.proc_handler = &proc_dointvec,
},
{}
};
static ctl_table pfm_sysctl_dir[] = {
{
.ctl_name = CTL_UNNUMBERED,
.procname = "perfmon",
.mode = 0555,
.child = pfm_ctl_table,
},
{}
};
static ctl_table pfm_sysctl_root[] = {
{
.ctl_name = CTL_KERN,
.procname = "kernel",
.mode = 0555,
.child = pfm_sysctl_dir,
},
{}
};
static struct ctl_table_header *pfm_sysctl_header;
static int pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
#define pfm_get_cpu_var(v) __ia64_per_cpu_var(v)
#define pfm_get_cpu_data(a,b) per_cpu(a, b)
static inline void
pfm_put_task(struct task_struct *task)
{
if (task != current) put_task_struct(task);
}
static inline void
pfm_reserve_page(unsigned long a)
{
SetPageReserved(vmalloc_to_page((void *)a));
}
static inline void
pfm_unreserve_page(unsigned long a)
{
ClearPageReserved(vmalloc_to_page((void*)a));
}
static inline unsigned long
pfm_protect_ctx_ctxsw(pfm_context_t *x)
{
spin_lock(&(x)->ctx_lock);
return 0UL;
}
static inline void
pfm_unprotect_ctx_ctxsw(pfm_context_t *x, unsigned long f)
{
spin_unlock(&(x)->ctx_lock);
}
static inline unsigned int
pfm_do_munmap(struct mm_struct *mm, unsigned long addr, size_t len, int acct)
{
return do_munmap(mm, addr, len);
}
static inline unsigned long
pfm_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags, unsigned long exec)
{
return get_unmapped_area(file, addr, len, pgoff, flags);
}
static int
pfmfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data,
struct vfsmount *mnt)
{
return get_sb_pseudo(fs_type, "pfm:", NULL, PFMFS_MAGIC, mnt);
}
static struct file_system_type pfm_fs_type = {
.name = "pfmfs",
.get_sb = pfmfs_get_sb,
.kill_sb = kill_anon_super,
};
DEFINE_PER_CPU(unsigned long, pfm_syst_info);
DEFINE_PER_CPU(struct task_struct *, pmu_owner);
DEFINE_PER_CPU(pfm_context_t *, pmu_ctx);
DEFINE_PER_CPU(unsigned long, pmu_activation_number);
EXPORT_PER_CPU_SYMBOL_GPL(pfm_syst_info);
/* forward declaration */
static const struct file_operations pfm_file_ops;
/*
* forward declarations
*/
#ifndef CONFIG_SMP
static void pfm_lazy_save_regs (struct task_struct *ta);
#endif
void dump_pmu_state(const char *);
static int pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
#include "perfmon_itanium.h"
#include "perfmon_mckinley.h"
#include "perfmon_montecito.h"
#include "perfmon_generic.h"
static pmu_config_t *pmu_confs[]={
&pmu_conf_mont,
&pmu_conf_mck,
&pmu_conf_ita,
&pmu_conf_gen, /* must be last */
NULL
};
static int pfm_end_notify_user(pfm_context_t *ctx);
static inline void
pfm_clear_psr_pp(void)
{
ia64_rsm(IA64_PSR_PP);
ia64_srlz_i();
}
static inline void
pfm_set_psr_pp(void)
{
ia64_ssm(IA64_PSR_PP);
ia64_srlz_i();
}
static inline void
pfm_clear_psr_up(void)
{
ia64_rsm(IA64_PSR_UP);
ia64_srlz_i();
}
static inline void
pfm_set_psr_up(void)
{
ia64_ssm(IA64_PSR_UP);
ia64_srlz_i();
}
static inline unsigned long
pfm_get_psr(void)
{
unsigned long tmp;
tmp = ia64_getreg(_IA64_REG_PSR);
ia64_srlz_i();
return tmp;
}
static inline void
pfm_set_psr_l(unsigned long val)
{
ia64_setreg(_IA64_REG_PSR_L, val);
ia64_srlz_i();
}
static inline void
pfm_freeze_pmu(void)
{
ia64_set_pmc(0,1UL);
ia64_srlz_d();
}
static inline void
pfm_unfreeze_pmu(void)
{
ia64_set_pmc(0,0UL);
ia64_srlz_d();
}
static inline void
pfm_restore_ibrs(unsigned long *ibrs, unsigned int nibrs)
{
int i;
for (i=0; i < nibrs; i++) {
ia64_set_ibr(i, ibrs[i]);
ia64_dv_serialize_instruction();
}
ia64_srlz_i();
}
static inline void
pfm_restore_dbrs(unsigned long *dbrs, unsigned int ndbrs)
{
int i;
for (i=0; i < ndbrs; i++) {
ia64_set_dbr(i, dbrs[i]);
ia64_dv_serialize_data();
}
ia64_srlz_d();
}
/*
* PMD[i] must be a counter. no check is made
*/
static inline unsigned long
pfm_read_soft_counter(pfm_context_t *ctx, int i)
{
return ctx->ctx_pmds[i].val + (ia64_get_pmd(i) & pmu_conf->ovfl_val);
}
/*
* PMD[i] must be a counter. no check is made
*/
static inline void
pfm_write_soft_counter(pfm_context_t *ctx, int i, unsigned long val)
{
unsigned long ovfl_val = pmu_conf->ovfl_val;
ctx->ctx_pmds[i].val = val & ~ovfl_val;
/*
* writing to unimplemented part is ignore, so we do not need to
* mask off top part
*/
ia64_set_pmd(i, val & ovfl_val);
}
static pfm_msg_t *
pfm_get_new_msg(pfm_context_t *ctx)
{
int idx, next;
next = (ctx->ctx_msgq_tail+1) % PFM_MAX_MSGS;
DPRINT(("ctx_fd=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
if (next == ctx->ctx_msgq_head) return NULL;
idx = ctx->ctx_msgq_tail;
ctx->ctx_msgq_tail = next;
DPRINT(("ctx=%p head=%d tail=%d msg=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, idx));
return ctx->ctx_msgq+idx;
}
static pfm_msg_t *
pfm_get_next_msg(pfm_context_t *ctx)
{
pfm_msg_t *msg;
DPRINT(("ctx=%p head=%d tail=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
if (PFM_CTXQ_EMPTY(ctx)) return NULL;
/*
* get oldest message
*/
msg = ctx->ctx_msgq+ctx->ctx_msgq_head;
/*
* and move forward
*/
ctx->ctx_msgq_head = (ctx->ctx_msgq_head+1) % PFM_MAX_MSGS;
DPRINT(("ctx=%p head=%d tail=%d type=%d\n", ctx, ctx->ctx_msgq_head, ctx->ctx_msgq_tail, msg->pfm_gen_msg.msg_type));
return msg;
}
static void
pfm_reset_msgq(pfm_context_t *ctx)
{
ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
DPRINT(("ctx=%p msgq reset\n", ctx));
}
static void *
pfm_rvmalloc(unsigned long size)
{
void *mem;
unsigned long addr;
size = PAGE_ALIGN(size);
mem = vmalloc(size);
if (mem) {
//printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);
memset(mem, 0, size);
addr = (unsigned long)mem;
while (size > 0) {
pfm_reserve_page(addr);
addr+=PAGE_SIZE;
size-=PAGE_SIZE;
}
}
return mem;
}
static void
pfm_rvfree(void *mem, unsigned long size)
{
unsigned long addr;
if (mem) {
DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));
addr = (unsigned long) mem;
while ((long) size > 0) {
pfm_unreserve_page(addr);
addr+=PAGE_SIZE;
size-=PAGE_SIZE;
}
vfree(mem);
}
return;
}
static pfm_context_t *
pfm_context_alloc(int ctx_flags)
{
pfm_context_t *ctx;
/*
* allocate context descriptor
* must be able to free with interrupts disabled
*/
ctx = kzalloc(sizeof(pfm_context_t), GFP_KERNEL);
if (ctx) {
DPRINT(("alloc ctx @%p\n", ctx));
/*
* init context protection lock
*/
spin_lock_init(&ctx->ctx_lock);
/*
* context is unloaded
*/
ctx->ctx_state = PFM_CTX_UNLOADED;
/*
* initialization of context's flags
*/
ctx->ctx_fl_block = (ctx_flags & PFM_FL_NOTIFY_BLOCK) ? 1 : 0;
ctx->ctx_fl_system = (ctx_flags & PFM_FL_SYSTEM_WIDE) ? 1: 0;
ctx->ctx_fl_no_msg = (ctx_flags & PFM_FL_OVFL_NO_MSG) ? 1: 0;
/*
* will move to set properties
* ctx->ctx_fl_excl_idle = (ctx_flags & PFM_FL_EXCL_IDLE) ? 1: 0;
*/
/*
* init restart semaphore to locked
*/
init_completion(&ctx->ctx_restart_done);
/*
* activation is used in SMP only
*/
ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
SET_LAST_CPU(ctx, -1);
/*
* initialize notification message queue
*/
ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
init_waitqueue_head(&ctx->ctx_msgq_wait);
init_waitqueue_head(&ctx->ctx_zombieq);
}
return ctx;
}
static void
pfm_context_free(pfm_context_t *ctx)
{
if (ctx) {
DPRINT(("free ctx @%p\n", ctx));
kfree(ctx);
}
}
static void
pfm_mask_monitoring(struct task_struct *task)
{
pfm_context_t *ctx = PFM_GET_CTX(task);
unsigned long mask, val, ovfl_mask;
int i;
DPRINT_ovfl(("masking monitoring for [%d]\n", task_pid_nr(task)));
ovfl_mask = pmu_conf->ovfl_val;
/*
* monitoring can only be masked as a result of a valid
* counter overflow. In UP, it means that the PMU still
* has an owner. Note that the owner can be different
* from the current task. However the PMU state belongs
* to the owner.
* In SMP, a valid overflow only happens when task is
* current. Therefore if we come here, we know that
* the PMU state belongs to the current task, therefore
* we can access the live registers.
*
* So in both cases, the live register contains the owner's
* state. We can ONLY touch the PMU registers and NOT the PSR.
*
* As a consequence to this call, the ctx->th_pmds[] array
* contains stale information which must be ignored
* when context is reloaded AND monitoring is active (see
* pfm_restart).
*/
mask = ctx->ctx_used_pmds[0];
for (i = 0; mask; i++, mask>>=1) {
/* skip non used pmds */
if ((mask & 0x1) == 0) continue;
val = ia64_get_pmd(i);
if (PMD_IS_COUNTING(i)) {
/*
* we rebuild the full 64 bit value of the counter
*/
ctx->ctx_pmds[i].val += (val & ovfl_mask);
} else {
ctx->ctx_pmds[i].val = val;
}
DPRINT_ovfl(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
i,
ctx->ctx_pmds[i].val,
val & ovfl_mask));
}
/*
* mask monitoring by setting the privilege level to 0
* we cannot use psr.pp/psr.up for this, it is controlled by
* the user
*
* if task is current, modify actual registers, otherwise modify
* thread save state, i.e., what will be restored in pfm_load_regs()
*/
mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0UL) continue;
ia64_set_pmc(i, ctx->th_pmcs[i] & ~0xfUL);
ctx->th_pmcs[i] &= ~0xfUL;
DPRINT_ovfl(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
}
/*
* make all of this visible
*/
ia64_srlz_d();
}
/*
* must always be done with task == current
*
* context must be in MASKED state when calling
*/
static void
pfm_restore_monitoring(struct task_struct *task)
{
pfm_context_t *ctx = PFM_GET_CTX(task);
unsigned long mask, ovfl_mask;
unsigned long psr, val;
int i, is_system;
is_system = ctx->ctx_fl_system;
ovfl_mask = pmu_conf->ovfl_val;
if (task != current) {
printk(KERN_ERR "perfmon.%d: invalid task[%d] current[%d]\n", __LINE__, task_pid_nr(task), task_pid_nr(current));
return;
}
if (ctx->ctx_state != PFM_CTX_MASKED) {
printk(KERN_ERR "perfmon.%d: task[%d] current[%d] invalid state=%d\n", __LINE__,
task_pid_nr(task), task_pid_nr(current), ctx->ctx_state);
return;
}
psr = pfm_get_psr();
/*
* monitoring is masked via the PMC.
* As we restore their value, we do not want each counter to
* restart right away. We stop monitoring using the PSR,
* restore the PMC (and PMD) and then re-establish the psr
* as it was. Note that there can be no pending overflow at
* this point, because monitoring was MASKED.
*
* system-wide session are pinned and self-monitoring
*/
if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
/* disable dcr pp */
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
pfm_clear_psr_pp();
} else {
pfm_clear_psr_up();
}
/*
* first, we restore the PMD
*/
mask = ctx->ctx_used_pmds[0];
for (i = 0; mask; i++, mask>>=1) {
/* skip non used pmds */
if ((mask & 0x1) == 0) continue;
if (PMD_IS_COUNTING(i)) {
/*
* we split the 64bit value according to
* counter width
*/
val = ctx->ctx_pmds[i].val & ovfl_mask;
ctx->ctx_pmds[i].val &= ~ovfl_mask;
} else {
val = ctx->ctx_pmds[i].val;
}
ia64_set_pmd(i, val);
DPRINT(("pmd[%d]=0x%lx hw_pmd=0x%lx\n",
i,
ctx->ctx_pmds[i].val,
val));
}
/*
* restore the PMCs
*/
mask = ctx->ctx_used_monitors[0] >> PMU_FIRST_COUNTER;
for(i= PMU_FIRST_COUNTER; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0UL) continue;
ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
ia64_set_pmc(i, ctx->th_pmcs[i]);
DPRINT(("[%d] pmc[%d]=0x%lx\n",
task_pid_nr(task), i, ctx->th_pmcs[i]));
}
ia64_srlz_d();
/*
* must restore DBR/IBR because could be modified while masked
* XXX: need to optimize
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* now restore PSR
*/
if (is_system && (PFM_CPUINFO_GET() & PFM_CPUINFO_DCR_PP)) {
/* enable dcr pp */
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
ia64_srlz_i();
}
pfm_set_psr_l(psr);
}
static inline void
pfm_save_pmds(unsigned long *pmds, unsigned long mask)
{
int i;
ia64_srlz_d();
for (i=0; mask; i++, mask>>=1) {
if (mask & 0x1) pmds[i] = ia64_get_pmd(i);
}
}
/*
* reload from thread state (used for ctxw only)
*/
static inline void
pfm_restore_pmds(unsigned long *pmds, unsigned long mask)
{
int i;
unsigned long val, ovfl_val = pmu_conf->ovfl_val;
for (i=0; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0) continue;
val = PMD_IS_COUNTING(i) ? pmds[i] & ovfl_val : pmds[i];
ia64_set_pmd(i, val);
}
ia64_srlz_d();
}
/*
* propagate PMD from context to thread-state
*/
static inline void
pfm_copy_pmds(struct task_struct *task, pfm_context_t *ctx)
{
unsigned long ovfl_val = pmu_conf->ovfl_val;
unsigned long mask = ctx->ctx_all_pmds[0];
unsigned long val;
int i;
DPRINT(("mask=0x%lx\n", mask));
for (i=0; mask; i++, mask>>=1) {
val = ctx->ctx_pmds[i].val;
/*
* We break up the 64 bit value into 2 pieces
* the lower bits go to the machine state in the
* thread (will be reloaded on ctxsw in).
* The upper part stays in the soft-counter.
*/
if (PMD_IS_COUNTING(i)) {
ctx->ctx_pmds[i].val = val & ~ovfl_val;
val &= ovfl_val;
}
ctx->th_pmds[i] = val;
DPRINT(("pmd[%d]=0x%lx soft_val=0x%lx\n",
i,
ctx->th_pmds[i],
ctx->ctx_pmds[i].val));
}
}
/*
* propagate PMC from context to thread-state
*/
static inline void
pfm_copy_pmcs(struct task_struct *task, pfm_context_t *ctx)
{
unsigned long mask = ctx->ctx_all_pmcs[0];
int i;
DPRINT(("mask=0x%lx\n", mask));
for (i=0; mask; i++, mask>>=1) {
/* masking 0 with ovfl_val yields 0 */
ctx->th_pmcs[i] = ctx->ctx_pmcs[i];
DPRINT(("pmc[%d]=0x%lx\n", i, ctx->th_pmcs[i]));
}
}
static inline void
pfm_restore_pmcs(unsigned long *pmcs, unsigned long mask)
{
int i;
for (i=0; mask; i++, mask>>=1) {
if ((mask & 0x1) == 0) continue;
ia64_set_pmc(i, pmcs[i]);
}
ia64_srlz_d();
}
static inline int
pfm_uuid_cmp(pfm_uuid_t a, pfm_uuid_t b)
{
return memcmp(a, b, sizeof(pfm_uuid_t));
}
static inline int
pfm_buf_fmt_exit(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, struct pt_regs *regs)
{
int ret = 0;
if (fmt->fmt_exit) ret = (*fmt->fmt_exit)(task, buf, regs);
return ret;
}
static inline int
pfm_buf_fmt_getsize(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags, int cpu, void *arg, unsigned long *size)
{
int ret = 0;
if (fmt->fmt_getsize) ret = (*fmt->fmt_getsize)(task, flags, cpu, arg, size);
return ret;
}
static inline int
pfm_buf_fmt_validate(pfm_buffer_fmt_t *fmt, struct task_struct *task, unsigned int flags,
int cpu, void *arg)
{
int ret = 0;
if (fmt->fmt_validate) ret = (*fmt->fmt_validate)(task, flags, cpu, arg);
return ret;
}
static inline int
pfm_buf_fmt_init(pfm_buffer_fmt_t *fmt, struct task_struct *task, void *buf, unsigned int flags,
int cpu, void *arg)
{
int ret = 0;
if (fmt->fmt_init) ret = (*fmt->fmt_init)(task, buf, flags, cpu, arg);
return ret;
}
static inline int
pfm_buf_fmt_restart(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
{
int ret = 0;
if (fmt->fmt_restart) ret = (*fmt->fmt_restart)(task, ctrl, buf, regs);
return ret;
}
static inline int
pfm_buf_fmt_restart_active(pfm_buffer_fmt_t *fmt, struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
{
int ret = 0;
if (fmt->fmt_restart_active) ret = (*fmt->fmt_restart_active)(task, ctrl, buf, regs);
return ret;
}
static pfm_buffer_fmt_t *
__pfm_find_buffer_fmt(pfm_uuid_t uuid)
{
struct list_head * pos;
pfm_buffer_fmt_t * entry;
list_for_each(pos, &pfm_buffer_fmt_list) {
entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
if (pfm_uuid_cmp(uuid, entry->fmt_uuid) == 0)
return entry;
}
return NULL;
}
/*
* find a buffer format based on its uuid
*/
static pfm_buffer_fmt_t *
pfm_find_buffer_fmt(pfm_uuid_t uuid)
{
pfm_buffer_fmt_t * fmt;
spin_lock(&pfm_buffer_fmt_lock);
fmt = __pfm_find_buffer_fmt(uuid);
spin_unlock(&pfm_buffer_fmt_lock);
return fmt;
}
int
pfm_register_buffer_fmt(pfm_buffer_fmt_t *fmt)
{
int ret = 0;
/* some sanity checks */
if (fmt == NULL || fmt->fmt_name == NULL) return -EINVAL;
/* we need at least a handler */
if (fmt->fmt_handler == NULL) return -EINVAL;
/*
* XXX: need check validity of fmt_arg_size
*/
spin_lock(&pfm_buffer_fmt_lock);
if (__pfm_find_buffer_fmt(fmt->fmt_uuid)) {
printk(KERN_ERR "perfmon: duplicate sampling format: %s\n", fmt->fmt_name);
ret = -EBUSY;
goto out;
}
list_add(&fmt->fmt_list, &pfm_buffer_fmt_list);
printk(KERN_INFO "perfmon: added sampling format %s\n", fmt->fmt_name);
out:
spin_unlock(&pfm_buffer_fmt_lock);
return ret;
}
EXPORT_SYMBOL(pfm_register_buffer_fmt);
int
pfm_unregister_buffer_fmt(pfm_uuid_t uuid)
{
pfm_buffer_fmt_t *fmt;
int ret = 0;
spin_lock(&pfm_buffer_fmt_lock);
fmt = __pfm_find_buffer_fmt(uuid);
if (!fmt) {
printk(KERN_ERR "perfmon: cannot unregister format, not found\n");
ret = -EINVAL;
goto out;
}
list_del_init(&fmt->fmt_list);
printk(KERN_INFO "perfmon: removed sampling format: %s\n", fmt->fmt_name);
out:
spin_unlock(&pfm_buffer_fmt_lock);
return ret;
}
EXPORT_SYMBOL(pfm_unregister_buffer_fmt);
extern void update_pal_halt_status(int);
static int
pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu)
{
unsigned long flags;
/*
* validity checks on cpu_mask have been done upstream
*/
LOCK_PFS(flags);
DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
if (is_syswide) {
/*
* cannot mix system wide and per-task sessions
*/
if (pfm_sessions.pfs_task_sessions > 0UL) {
DPRINT(("system wide not possible, %u conflicting task_sessions\n",
pfm_sessions.pfs_task_sessions));
goto abort;
}
if (pfm_sessions.pfs_sys_session[cpu]) goto error_conflict;
DPRINT(("reserving system wide session on CPU%u currently on CPU%u\n", cpu, smp_processor_id()));
pfm_sessions.pfs_sys_session[cpu] = task;
pfm_sessions.pfs_sys_sessions++ ;
} else {
if (pfm_sessions.pfs_sys_sessions) goto abort;
pfm_sessions.pfs_task_sessions++;
}
DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
/*
* disable default_idle() to go to PAL_HALT
*/
update_pal_halt_status(0);
UNLOCK_PFS(flags);
return 0;
error_conflict:
DPRINT(("system wide not possible, conflicting session [%d] on CPU%d\n",
task_pid_nr(pfm_sessions.pfs_sys_session[cpu]),
cpu));
abort:
UNLOCK_PFS(flags);
return -EBUSY;
}
static int
pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu)
{
unsigned long flags;
/*
* validity checks on cpu_mask have been done upstream
*/
LOCK_PFS(flags);
DPRINT(("in sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
if (is_syswide) {
pfm_sessions.pfs_sys_session[cpu] = NULL;
/*
* would not work with perfmon+more than one bit in cpu_mask
*/
if (ctx && ctx->ctx_fl_using_dbreg) {
if (pfm_sessions.pfs_sys_use_dbregs == 0) {
printk(KERN_ERR "perfmon: invalid release for ctx %p sys_use_dbregs=0\n", ctx);
} else {
pfm_sessions.pfs_sys_use_dbregs--;
}
}
pfm_sessions.pfs_sys_sessions--;
} else {
pfm_sessions.pfs_task_sessions--;
}
DPRINT(("out sys_sessions=%u task_sessions=%u dbregs=%u syswide=%d cpu=%u\n",
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_use_dbregs,
is_syswide,
cpu));
/*
* if possible, enable default_idle() to go into PAL_HALT
*/
if (pfm_sessions.pfs_task_sessions == 0 && pfm_sessions.pfs_sys_sessions == 0)
update_pal_halt_status(1);
UNLOCK_PFS(flags);
return 0;
}
/*
* removes virtual mapping of the sampling buffer.
* IMPORTANT: cannot be called with interrupts disable, e.g. inside
* a PROTECT_CTX() section.
*/
static int
pfm_remove_smpl_mapping(struct task_struct *task, void *vaddr, unsigned long size)
{
int r;
/* sanity checks */
if (task->mm == NULL || size == 0UL || vaddr == NULL) {
printk(KERN_ERR "perfmon: pfm_remove_smpl_mapping [%d] invalid context mm=%p\n", task_pid_nr(task), task->mm);
return -EINVAL;
}
DPRINT(("smpl_vaddr=%p size=%lu\n", vaddr, size));
/*
* does the actual unmapping
*/
down_write(&task->mm->mmap_sem);
DPRINT(("down_write done smpl_vaddr=%p size=%lu\n", vaddr, size));
r = pfm_do_munmap(task->mm, (unsigned long)vaddr, size, 0);
up_write(&task->mm->mmap_sem);
if (r !=0) {
printk(KERN_ERR "perfmon: [%d] unable to unmap sampling buffer @%p size=%lu\n", task_pid_nr(task), vaddr, size);
}
DPRINT(("do_unmap(%p, %lu)=%d\n", vaddr, size, r));
return 0;
}
/*
* free actual physical storage used by sampling buffer
*/
#if 0
static int
pfm_free_smpl_buffer(pfm_context_t *ctx)
{
pfm_buffer_fmt_t *fmt;
if (ctx->ctx_smpl_hdr == NULL) goto invalid_free;
/*
* we won't use the buffer format anymore
*/
fmt = ctx->ctx_buf_fmt;
DPRINT(("sampling buffer @%p size %lu vaddr=%p\n",
ctx->ctx_smpl_hdr,
ctx->ctx_smpl_size,
ctx->ctx_smpl_vaddr));
pfm_buf_fmt_exit(fmt, current, NULL, NULL);
/*
* free the buffer
*/
pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);
ctx->ctx_smpl_hdr = NULL;
ctx->ctx_smpl_size = 0UL;
return 0;
invalid_free:
printk(KERN_ERR "perfmon: pfm_free_smpl_buffer [%d] no buffer\n", task_pid_nr(current));
return -EINVAL;
}
#endif
static inline void
pfm_exit_smpl_buffer(pfm_buffer_fmt_t *fmt)
{
if (fmt == NULL) return;
pfm_buf_fmt_exit(fmt, current, NULL, NULL);
}
/*
* pfmfs should _never_ be mounted by userland - too much of security hassle,
* no real gain from having the whole whorehouse mounted. So we don't need
* any operations on the root directory. However, we need a non-trivial
* d_name - pfm: will go nicely and kill the special-casing in procfs.
*/
static struct vfsmount *pfmfs_mnt;
static int __init
init_pfm_fs(void)
{
int err = register_filesystem(&pfm_fs_type);
if (!err) {
pfmfs_mnt = kern_mount(&pfm_fs_type);
err = PTR_ERR(pfmfs_mnt);
if (IS_ERR(pfmfs_mnt))
unregister_filesystem(&pfm_fs_type);
else
err = 0;
}
return err;
}
static ssize_t
pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
{
pfm_context_t *ctx;
pfm_msg_t *msg;
ssize_t ret;
unsigned long flags;
DECLARE_WAITQUEUE(wait, current);
if (PFM_IS_FILE(filp) == 0) {
printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
return -EINVAL;
}
ctx = (pfm_context_t *)filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_read: NULL ctx [%d]\n", task_pid_nr(current));
return -EINVAL;
}
/*
* check even when there is no message
*/
if (size < sizeof(pfm_msg_t)) {
DPRINT(("message is too small ctx=%p (>=%ld)\n", ctx, sizeof(pfm_msg_t)));
return -EINVAL;
}
PROTECT_CTX(ctx, flags);
/*
* put ourselves on the wait queue
*/
add_wait_queue(&ctx->ctx_msgq_wait, &wait);
for(;;) {
/*
* check wait queue
*/
set_current_state(TASK_INTERRUPTIBLE);
DPRINT(("head=%d tail=%d\n", ctx->ctx_msgq_head, ctx->ctx_msgq_tail));
ret = 0;
if(PFM_CTXQ_EMPTY(ctx) == 0) break;
UNPROTECT_CTX(ctx, flags);
/*
* check non-blocking read
*/
ret = -EAGAIN;
if(filp->f_flags & O_NONBLOCK) break;
/*
* check pending signals
*/
if(signal_pending(current)) {
ret = -EINTR;
break;
}
/*
* no message, so wait
*/
schedule();
PROTECT_CTX(ctx, flags);
}
DPRINT(("[%d] back to running ret=%ld\n", task_pid_nr(current), ret));
set_current_state(TASK_RUNNING);
remove_wait_queue(&ctx->ctx_msgq_wait, &wait);
if (ret < 0) goto abort;
ret = -EINVAL;
msg = pfm_get_next_msg(ctx);
if (msg == NULL) {
printk(KERN_ERR "perfmon: pfm_read no msg for ctx=%p [%d]\n", ctx, task_pid_nr(current));
goto abort_locked;
}
DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
ret = -EFAULT;
if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
abort_locked:
UNPROTECT_CTX(ctx, flags);
abort:
return ret;
}
static ssize_t
pfm_write(struct file *file, const char __user *ubuf,
size_t size, loff_t *ppos)
{
DPRINT(("pfm_write called\n"));
return -EINVAL;
}
static unsigned int
pfm_poll(struct file *filp, poll_table * wait)
{
pfm_context_t *ctx;
unsigned long flags;
unsigned int mask = 0;
if (PFM_IS_FILE(filp) == 0) {
printk(KERN_ERR "perfmon: pfm_poll: bad magic [%d]\n", task_pid_nr(current));
return 0;
}
ctx = (pfm_context_t *)filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_poll: NULL ctx [%d]\n", task_pid_nr(current));
return 0;
}
DPRINT(("pfm_poll ctx_fd=%d before poll_wait\n", ctx->ctx_fd));
poll_wait(filp, &ctx->ctx_msgq_wait, wait);
PROTECT_CTX(ctx, flags);
if (PFM_CTXQ_EMPTY(ctx) == 0)
mask = POLLIN | POLLRDNORM;
UNPROTECT_CTX(ctx, flags);
DPRINT(("pfm_poll ctx_fd=%d mask=0x%x\n", ctx->ctx_fd, mask));
return mask;
}
static int
pfm_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
DPRINT(("pfm_ioctl called\n"));
return -EINVAL;
}
/*
* interrupt cannot be masked when coming here
*/
static inline int
pfm_do_fasync(int fd, struct file *filp, pfm_context_t *ctx, int on)
{
int ret;
ret = fasync_helper (fd, filp, on, &ctx->ctx_async_queue);
DPRINT(("pfm_fasync called by [%d] on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
task_pid_nr(current),
fd,
on,
ctx->ctx_async_queue, ret));
return ret;
}
static int
pfm_fasync(int fd, struct file *filp, int on)
{
pfm_context_t *ctx;
int ret;
if (PFM_IS_FILE(filp) == 0) {
printk(KERN_ERR "perfmon: pfm_fasync bad magic [%d]\n", task_pid_nr(current));
return -EBADF;
}
ctx = (pfm_context_t *)filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_fasync NULL ctx [%d]\n", task_pid_nr(current));
return -EBADF;
}
/*
* we cannot mask interrupts during this call because this may
* may go to sleep if memory is not readily avalaible.
*
* We are protected from the conetxt disappearing by the get_fd()/put_fd()
* done in caller. Serialization of this function is ensured by caller.
*/
ret = pfm_do_fasync(fd, filp, ctx, on);
DPRINT(("pfm_fasync called on ctx_fd=%d on=%d async_queue=%p ret=%d\n",
fd,
on,
ctx->ctx_async_queue, ret));
return ret;
}
#ifdef CONFIG_SMP
/*
* this function is exclusively called from pfm_close().
* The context is not protected at that time, nor are interrupts
* on the remote CPU. That's necessary to avoid deadlocks.
*/
static void
pfm_syswide_force_stop(void *info)
{
pfm_context_t *ctx = (pfm_context_t *)info;
struct pt_regs *regs = task_pt_regs(current);
struct task_struct *owner;
unsigned long flags;
int ret;
if (ctx->ctx_cpu != smp_processor_id()) {
printk(KERN_ERR "perfmon: pfm_syswide_force_stop for CPU%d but on CPU%d\n",
ctx->ctx_cpu,
smp_processor_id());
return;
}
owner = GET_PMU_OWNER();
if (owner != ctx->ctx_task) {
printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected owner [%d] instead of [%d]\n",
smp_processor_id(),
task_pid_nr(owner), task_pid_nr(ctx->ctx_task));
return;
}
if (GET_PMU_CTX() != ctx) {
printk(KERN_ERR "perfmon: pfm_syswide_force_stop CPU%d unexpected ctx %p instead of %p\n",
smp_processor_id(),
GET_PMU_CTX(), ctx);
return;
}
DPRINT(("on CPU%d forcing system wide stop for [%d]\n", smp_processor_id(), task_pid_nr(ctx->ctx_task)));
/*
* the context is already protected in pfm_close(), we simply
* need to mask interrupts to avoid a PMU interrupt race on
* this CPU
*/
local_irq_save(flags);
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
DPRINT(("context_unload returned %d\n", ret));
}
/*
* unmask interrupts, PMU interrupts are now spurious here
*/
local_irq_restore(flags);
}
static void
pfm_syswide_cleanup_other_cpu(pfm_context_t *ctx)
{
int ret;
DPRINT(("calling CPU%d for cleanup\n", ctx->ctx_cpu));
ret = smp_call_function_single(ctx->ctx_cpu, pfm_syswide_force_stop, ctx, 0, 1);
DPRINT(("called CPU%d for cleanup ret=%d\n", ctx->ctx_cpu, ret));
}
#endif /* CONFIG_SMP */
/*
* called for each close(). Partially free resources.
* When caller is self-monitoring, the context is unloaded.
*/
static int
pfm_flush(struct file *filp, fl_owner_t id)
{
pfm_context_t *ctx;
struct task_struct *task;
struct pt_regs *regs;
unsigned long flags;
unsigned long smpl_buf_size = 0UL;
void *smpl_buf_vaddr = NULL;
int state, is_system;
if (PFM_IS_FILE(filp) == 0) {
DPRINT(("bad magic for\n"));
return -EBADF;
}
ctx = (pfm_context_t *)filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_flush: NULL ctx [%d]\n", task_pid_nr(current));
return -EBADF;
}
/*
* remove our file from the async queue, if we use this mode.
* This can be done without the context being protected. We come
* here when the context has become unreachable by other tasks.
*
* We may still have active monitoring at this point and we may
* end up in pfm_overflow_handler(). However, fasync_helper()
* operates with interrupts disabled and it cleans up the
* queue. If the PMU handler is called prior to entering
* fasync_helper() then it will send a signal. If it is
* invoked after, it will find an empty queue and no
* signal will be sent. In both case, we are safe
*/
PROTECT_CTX(ctx, flags);
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
task = PFM_CTX_TASK(ctx);
regs = task_pt_regs(task);
DPRINT(("ctx_state=%d is_current=%d\n",
state,
task == current ? 1 : 0));
/*
* if state == UNLOADED, then task is NULL
*/
/*
* we must stop and unload because we are losing access to the context.
*/
if (task == current) {
#ifdef CONFIG_SMP
/*
* the task IS the owner but it migrated to another CPU: that's bad
* but we must handle this cleanly. Unfortunately, the kernel does
* not provide a mechanism to block migration (while the context is loaded).
*
* We need to release the resource on the ORIGINAL cpu.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
/*
* keep context protected but unmask interrupt for IPI
*/
local_irq_restore(flags);
pfm_syswide_cleanup_other_cpu(ctx);
/*
* restore interrupt masking
*/
local_irq_save(flags);
/*
* context is unloaded at this point
*/
} else
#endif /* CONFIG_SMP */
{
DPRINT(("forcing unload\n"));
/*
* stop and unload, returning with state UNLOADED
* and session unreserved.
*/
pfm_context_unload(ctx, NULL, 0, regs);
DPRINT(("ctx_state=%d\n", ctx->ctx_state));
}
}
/*
* remove virtual mapping, if any, for the calling task.
* cannot reset ctx field until last user is calling close().
*
* ctx_smpl_vaddr must never be cleared because it is needed
* by every task with access to the context
*
* When called from do_exit(), the mm context is gone already, therefore
* mm is NULL, i.e., the VMA is already gone and we do not have to
* do anything here
*/
if (ctx->ctx_smpl_vaddr && current->mm) {
smpl_buf_vaddr = ctx->ctx_smpl_vaddr;
smpl_buf_size = ctx->ctx_smpl_size;
}
UNPROTECT_CTX(ctx, flags);
/*
* if there was a mapping, then we systematically remove it
* at this point. Cannot be done inside critical section
* because some VM function reenables interrupts.
*
*/
if (smpl_buf_vaddr) pfm_remove_smpl_mapping(current, smpl_buf_vaddr, smpl_buf_size);
return 0;
}
/*
* called either on explicit close() or from exit_files().
* Only the LAST user of the file gets to this point, i.e., it is
* called only ONCE.
*
* IMPORTANT: we get called ONLY when the refcnt on the file gets to zero
* (fput()),i.e, last task to access the file. Nobody else can access the
* file at this point.
*
* When called from exit_files(), the VMA has been freed because exit_mm()
* is executed before exit_files().
*
* When called from exit_files(), the current task is not yet ZOMBIE but we
* flush the PMU state to the context.
*/
static int
pfm_close(struct inode *inode, struct file *filp)
{
pfm_context_t *ctx;
struct task_struct *task;
struct pt_regs *regs;
DECLARE_WAITQUEUE(wait, current);
unsigned long flags;
unsigned long smpl_buf_size = 0UL;
void *smpl_buf_addr = NULL;
int free_possible = 1;
int state, is_system;
DPRINT(("pfm_close called private=%p\n", filp->private_data));
if (PFM_IS_FILE(filp) == 0) {
DPRINT(("bad magic\n"));
return -EBADF;
}
ctx = (pfm_context_t *)filp->private_data;
if (ctx == NULL) {
printk(KERN_ERR "perfmon: pfm_close: NULL ctx [%d]\n", task_pid_nr(current));
return -EBADF;
}
if (filp->f_flags & FASYNC) {
DPRINT(("cleaning up async_queue=%p\n", ctx->ctx_async_queue));
pfm_do_fasync(-1, filp, ctx, 0);
}
PROTECT_CTX(ctx, flags);
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
task = PFM_CTX_TASK(ctx);
regs = task_pt_regs(task);
DPRINT(("ctx_state=%d is_current=%d\n",
state,
task == current ? 1 : 0));
/*
* if task == current, then pfm_flush() unloaded the context
*/
if (state == PFM_CTX_UNLOADED) goto doit;
/*
* context is loaded/masked and task != current, we need to
* either force an unload or go zombie
*/
/*
* The task is currently blocked or will block after an overflow.
* we must force it to wakeup to get out of the
* MASKED state and transition to the unloaded state by itself.
*
* This situation is only possible for per-task mode
*/
if (state == PFM_CTX_MASKED && CTX_OVFL_NOBLOCK(ctx) == 0) {
/*
* set a "partial" zombie state to be checked
* upon return from down() in pfm_handle_work().
*
* We cannot use the ZOMBIE state, because it is checked
* by pfm_load_regs() which is called upon wakeup from down().
* In such case, it would free the context and then we would
* return to pfm_handle_work() which would access the
* stale context. Instead, we set a flag invisible to pfm_load_regs()
* but visible to pfm_handle_work().
*
* For some window of time, we have a zombie context with
* ctx_state = MASKED and not ZOMBIE
*/
ctx->ctx_fl_going_zombie = 1;
/*
* force task to wake up from MASKED state
*/
complete(&ctx->ctx_restart_done);
DPRINT(("waking up ctx_state=%d\n", state));
/*
* put ourself to sleep waiting for the other
* task to report completion
*
* the context is protected by mutex, therefore there
* is no risk of being notified of completion before
* begin actually on the waitq.
*/
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&ctx->ctx_zombieq, &wait);
UNPROTECT_CTX(ctx, flags);
/*
* XXX: check for signals :
* - ok for explicit close
* - not ok when coming from exit_files()
*/
schedule();
PROTECT_CTX(ctx, flags);
remove_wait_queue(&ctx->ctx_zombieq, &wait);
set_current_state(TASK_RUNNING);
/*
* context is unloaded at this point
*/
DPRINT(("after zombie wakeup ctx_state=%d for\n", state));
}
else if (task != current) {
#ifdef CONFIG_SMP
/*
* switch context to zombie state
*/
ctx->ctx_state = PFM_CTX_ZOMBIE;
DPRINT(("zombie ctx for [%d]\n", task_pid_nr(task)));
/*
* cannot free the context on the spot. deferred until
* the task notices the ZOMBIE state
*/
free_possible = 0;
#else
pfm_context_unload(ctx, NULL, 0, regs);
#endif
}
doit:
/* reload state, may have changed during opening of critical section */
state = ctx->ctx_state;
/*
* the context is still attached to a task (possibly current)
* we cannot destroy it right now
*/
/*
* we must free the sampling buffer right here because
* we cannot rely on it being cleaned up later by the
* monitored task. It is not possible to free vmalloc'ed
* memory in pfm_load_regs(). Instead, we remove the buffer
* now. should there be subsequent PMU overflow originally
* meant for sampling, the will be converted to spurious
* and that's fine because the monitoring tools is gone anyway.
*/
if (ctx->ctx_smpl_hdr) {
smpl_buf_addr = ctx->ctx_smpl_hdr;
smpl_buf_size = ctx->ctx_smpl_size;
/* no more sampling */
ctx->ctx_smpl_hdr = NULL;
ctx->ctx_fl_is_sampling = 0;
}
DPRINT(("ctx_state=%d free_possible=%d addr=%p size=%lu\n",
state,
free_possible,
smpl_buf_addr,
smpl_buf_size));
if (smpl_buf_addr) pfm_exit_smpl_buffer(ctx->ctx_buf_fmt);
/*
* UNLOADED that the session has already been unreserved.
*/
if (state == PFM_CTX_ZOMBIE) {
pfm_unreserve_session(ctx, ctx->ctx_fl_system , ctx->ctx_cpu);
}
/*
* disconnect file descriptor from context must be done
* before we unlock.
*/
filp->private_data = NULL;
/*
* if we free on the spot, the context is now completely unreachable
* from the callers side. The monitored task side is also cut, so we
* can freely cut.
*
* If we have a deferred free, only the caller side is disconnected.
*/
UNPROTECT_CTX(ctx, flags);
/*
* All memory free operations (especially for vmalloc'ed memory)
* MUST be done with interrupts ENABLED.
*/
if (smpl_buf_addr) pfm_rvfree(smpl_buf_addr, smpl_buf_size);
/*
* return the memory used by the context
*/
if (free_possible) pfm_context_free(ctx);
return 0;
}
static int
pfm_no_open(struct inode *irrelevant, struct file *dontcare)
{
DPRINT(("pfm_no_open called\n"));
return -ENXIO;
}
static const struct file_operations pfm_file_ops = {
.llseek = no_llseek,
.read = pfm_read,
.write = pfm_write,
.poll = pfm_poll,
.ioctl = pfm_ioctl,
.open = pfm_no_open, /* special open code to disallow open via /proc */
.fasync = pfm_fasync,
.release = pfm_close,
.flush = pfm_flush
};
static int
pfmfs_delete_dentry(struct dentry *dentry)
{
return 1;
}
static struct dentry_operations pfmfs_dentry_operations = {
.d_delete = pfmfs_delete_dentry,
};
static struct file *
pfm_alloc_file(pfm_context_t *ctx)
{
struct file *file;
struct inode *inode;
struct dentry *dentry;
char name[32];
struct qstr this;
/*
* allocate a new inode
*/
inode = new_inode(pfmfs_mnt->mnt_sb);
if (!inode)
return ERR_PTR(-ENOMEM);
DPRINT(("new inode ino=%ld @%p\n", inode->i_ino, inode));
inode->i_mode = S_IFCHR|S_IRUGO;
inode->i_uid = current->fsuid;
inode->i_gid = current->fsgid;
sprintf(name, "[%lu]", inode->i_ino);
this.name = name;
this.len = strlen(name);
this.hash = inode->i_ino;
/*
* allocate a new dcache entry
*/
dentry = d_alloc(pfmfs_mnt->mnt_sb->s_root, &this);
if (!dentry) {
iput(inode);
return ERR_PTR(-ENOMEM);
}
dentry->d_op = &pfmfs_dentry_operations;
d_add(dentry, inode);
file = alloc_file(pfmfs_mnt, dentry, FMODE_READ, &pfm_file_ops);
if (!file) {
dput(dentry);
return ERR_PTR(-ENFILE);
}
file->f_flags = O_RDONLY;
file->private_data = ctx;
return file;
}
static int
pfm_remap_buffer(struct vm_area_struct *vma, unsigned long buf, unsigned long addr, unsigned long size)
{
DPRINT(("CPU%d buf=0x%lx addr=0x%lx size=%ld\n", smp_processor_id(), buf, addr, size));
while (size > 0) {
unsigned long pfn = ia64_tpa(buf) >> PAGE_SHIFT;
if (remap_pfn_range(vma, addr, pfn, PAGE_SIZE, PAGE_READONLY))
return -ENOMEM;
addr += PAGE_SIZE;
buf += PAGE_SIZE;
size -= PAGE_SIZE;
}
return 0;
}
/*
* allocate a sampling buffer and remaps it into the user address space of the task
*/
static int
pfm_smpl_buffer_alloc(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned long rsize, void **user_vaddr)
{
struct mm_struct *mm = task->mm;
struct vm_area_struct *vma = NULL;
unsigned long size;
void *smpl_buf;
/*
* the fixed header + requested size and align to page boundary
*/
size = PAGE_ALIGN(rsize);
DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
/*
* check requested size to avoid Denial-of-service attacks
* XXX: may have to refine this test
* Check against address space limit.
*
* if ((mm->total_vm << PAGE_SHIFT) + len> task->rlim[RLIMIT_AS].rlim_cur)
* return -ENOMEM;
*/
if (size > task->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)
return -ENOMEM;
/*
* We do the easy to undo allocations first.
*
* pfm_rvmalloc(), clears the buffer, so there is no leak
*/
smpl_buf = pfm_rvmalloc(size);
if (smpl_buf == NULL) {
DPRINT(("Can't allocate sampling buffer\n"));
return -ENOMEM;
}
DPRINT(("smpl_buf @%p\n", smpl_buf));
/* allocate vma */
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma) {
DPRINT(("Cannot allocate vma\n"));
goto error_kmem;
}
/*
* partially initialize the vma for the sampling buffer
*/
vma->vm_mm = mm;
vma->vm_file = filp;
vma->vm_flags = VM_READ| VM_MAYREAD |VM_RESERVED;
vma->vm_page_prot = PAGE_READONLY; /* XXX may need to change */
/*
* Now we have everything we need and we can initialize
* and connect all the data structures
*/
ctx->ctx_smpl_hdr = smpl_buf;
ctx->ctx_smpl_size = size; /* aligned size */
/*
* Let's do the difficult operations next.
*
* now we atomically find some area in the address space and
* remap the buffer in it.
*/
down_write(&task->mm->mmap_sem);
/* find some free area in address space, must have mmap sem held */
vma->vm_start = pfm_get_unmapped_area(NULL, 0, size, 0, MAP_PRIVATE|MAP_ANONYMOUS, 0);
if (vma->vm_start == 0UL) {
DPRINT(("Cannot find unmapped area for size %ld\n", size));
up_write(&task->mm->mmap_sem);
goto error;
}
vma->vm_end = vma->vm_start + size;
vma->vm_pgoff = vma->vm_start >> PAGE_SHIFT;
DPRINT(("aligned size=%ld, hdr=%p mapped @0x%lx\n", size, ctx->ctx_smpl_hdr, vma->vm_start));
/* can only be applied to current task, need to have the mm semaphore held when called */
if (pfm_remap_buffer(vma, (unsigned long)smpl_buf, vma->vm_start, size)) {
DPRINT(("Can't remap buffer\n"));
up_write(&task->mm->mmap_sem);
goto error;
}
get_file(filp);
/*
* now insert the vma in the vm list for the process, must be
* done with mmap lock held
*/
insert_vm_struct(mm, vma);
mm->total_vm += size >> PAGE_SHIFT;
vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file,
vma_pages(vma));
up_write(&task->mm->mmap_sem);
/*
* keep track of user level virtual address
*/
ctx->ctx_smpl_vaddr = (void *)vma->vm_start;
*(unsigned long *)user_vaddr = vma->vm_start;
return 0;
error:
kmem_cache_free(vm_area_cachep, vma);
error_kmem:
pfm_rvfree(smpl_buf, size);
return -ENOMEM;
}
/*
* XXX: do something better here
*/
static int
pfm_bad_permissions(struct task_struct *task)
{
/* inspired by ptrace_attach() */
DPRINT(("cur: uid=%d gid=%d task: euid=%d suid=%d uid=%d egid=%d sgid=%d\n",
current->uid,
current->gid,
task->euid,
task->suid,
task->uid,
task->egid,
task->sgid));
return ((current->uid != task->euid)
|| (current->uid != task->suid)
|| (current->uid != task->uid)
|| (current->gid != task->egid)
|| (current->gid != task->sgid)
|| (current->gid != task->gid)) && !capable(CAP_SYS_PTRACE);
}
static int
pfarg_is_sane(struct task_struct *task, pfarg_context_t *pfx)
{
int ctx_flags;
/* valid signal */
ctx_flags = pfx->ctx_flags;
if (ctx_flags & PFM_FL_SYSTEM_WIDE) {
/*
* cannot block in this mode
*/
if (ctx_flags & PFM_FL_NOTIFY_BLOCK) {
DPRINT(("cannot use blocking mode when in system wide monitoring\n"));
return -EINVAL;
}
} else {
}
/* probably more to add here */
return 0;
}
static int
pfm_setup_buffer_fmt(struct task_struct *task, struct file *filp, pfm_context_t *ctx, unsigned int ctx_flags,
unsigned int cpu, pfarg_context_t *arg)
{
pfm_buffer_fmt_t *fmt = NULL;
unsigned long size = 0UL;
void *uaddr = NULL;
void *fmt_arg = NULL;
int ret = 0;
#define PFM_CTXARG_BUF_ARG(a) (pfm_buffer_fmt_t *)(a+1)
/* invoke and lock buffer format, if found */
fmt = pfm_find_buffer_fmt(arg->ctx_smpl_buf_id);
if (fmt == NULL) {
DPRINT(("[%d] cannot find buffer format\n", task_pid_nr(task)));
return -EINVAL;
}
/*
* buffer argument MUST be contiguous to pfarg_context_t
*/
if (fmt->fmt_arg_size) fmt_arg = PFM_CTXARG_BUF_ARG(arg);
ret = pfm_buf_fmt_validate(fmt, task, ctx_flags, cpu, fmt_arg);
DPRINT(("[%d] after validate(0x%x,%d,%p)=%d\n", task_pid_nr(task), ctx_flags, cpu, fmt_arg, ret));
if (ret) goto error;
/* link buffer format and context */
ctx->ctx_buf_fmt = fmt;
ctx->ctx_fl_is_sampling = 1; /* assume record() is defined */
/*
* check if buffer format wants to use perfmon buffer allocation/mapping service
*/
ret = pfm_buf_fmt_getsize(fmt, task, ctx_flags, cpu, fmt_arg, &size);
if (ret) goto error;
if (size) {
/*
* buffer is always remapped into the caller's address space
*/
ret = pfm_smpl_buffer_alloc(current, filp, ctx, size, &uaddr);
if (ret) goto error;
/* keep track of user address of buffer */
arg->ctx_smpl_vaddr = uaddr;
}
ret = pfm_buf_fmt_init(fmt, task, ctx->ctx_smpl_hdr, ctx_flags, cpu, fmt_arg);
error:
return ret;
}
static void
pfm_reset_pmu_state(pfm_context_t *ctx)
{
int i;
/*
* install reset values for PMC.
*/
for (i=1; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_IMPL(i) == 0) continue;
ctx->ctx_pmcs[i] = PMC_DFL_VAL(i);
DPRINT(("pmc[%d]=0x%lx\n", i, ctx->ctx_pmcs[i]));
}
/*
* PMD registers are set to 0UL when the context in memset()
*/
/*
* On context switched restore, we must restore ALL pmc and ALL pmd even
* when they are not actively used by the task. In UP, the incoming process
* may otherwise pick up left over PMC, PMD state from the previous process.
* As opposed to PMD, stale PMC can cause harm to the incoming
* process because they may change what is being measured.
* Therefore, we must systematically reinstall the entire
* PMC state. In SMP, the same thing is possible on the
* same CPU but also on between 2 CPUs.
*
* The problem with PMD is information leaking especially
* to user level when psr.sp=0
*
* There is unfortunately no easy way to avoid this problem
* on either UP or SMP. This definitively slows down the
* pfm_load_regs() function.
*/
/*
* bitmask of all PMCs accessible to this context
*
* PMC0 is treated differently.
*/
ctx->ctx_all_pmcs[0] = pmu_conf->impl_pmcs[0] & ~0x1;
/*
* bitmask of all PMDs that are accessible to this context
*/
ctx->ctx_all_pmds[0] = pmu_conf->impl_pmds[0];
DPRINT(("<%d> all_pmcs=0x%lx all_pmds=0x%lx\n", ctx->ctx_fd, ctx->ctx_all_pmcs[0],ctx->ctx_all_pmds[0]));
/*
* useful in case of re-enable after disable
*/
ctx->ctx_used_ibrs[0] = 0UL;
ctx->ctx_used_dbrs[0] = 0UL;
}
static int
pfm_ctx_getsize(void *arg, size_t *sz)
{
pfarg_context_t *req = (pfarg_context_t *)arg;
pfm_buffer_fmt_t *fmt;
*sz = 0;
if (!pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) return 0;
fmt = pfm_find_buffer_fmt(req->ctx_smpl_buf_id);
if (fmt == NULL) {
DPRINT(("cannot find buffer format\n"));
return -EINVAL;
}
/* get just enough to copy in user parameters */
*sz = fmt->fmt_arg_size;
DPRINT(("arg_size=%lu\n", *sz));
return 0;
}
/*
* cannot attach if :
* - kernel task
* - task not owned by caller
* - task incompatible with context mode
*/
static int
pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
{
/*
* no kernel task or task not owner by caller
*/
if (task->mm == NULL) {
DPRINT(("task [%d] has not memory context (kernel thread)\n", task_pid_nr(task)));
return -EPERM;
}
if (pfm_bad_permissions(task)) {
DPRINT(("no permission to attach to [%d]\n", task_pid_nr(task)));
return -EPERM;
}
/*
* cannot block in self-monitoring mode
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && task == current) {
DPRINT(("cannot load a blocking context on self for [%d]\n", task_pid_nr(task)));
return -EINVAL;
}
if (task->exit_state == EXIT_ZOMBIE) {
DPRINT(("cannot attach to zombie task [%d]\n", task_pid_nr(task)));
return -EBUSY;
}
/*
* always ok for self
*/
if (task == current) return 0;
if (!task_is_stopped_or_traced(task)) {
DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
return -EBUSY;
}
/*
* make sure the task is off any CPU
*/
wait_task_inactive(task);
/* more to come... */
return 0;
}
static int
pfm_get_task(pfm_context_t *ctx, pid_t pid, struct task_struct **task)
{
struct task_struct *p = current;
int ret;
/* XXX: need to add more checks here */
if (pid < 2) return -EPERM;
if (pid != task_pid_vnr(current)) {
read_lock(&tasklist_lock);
p = find_task_by_vpid(pid);
/* make sure task cannot go away while we operate on it */
if (p) get_task_struct(p);
read_unlock(&tasklist_lock);
if (p == NULL) return -ESRCH;
}
ret = pfm_task_incompatible(ctx, p);
if (ret == 0) {
*task = p;
} else if (p != current) {
pfm_put_task(p);
}
return ret;
}
static int
pfm_context_create(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
pfarg_context_t *req = (pfarg_context_t *)arg;
struct file *filp;
struct path path;
int ctx_flags;
int fd;
int ret;
/* let's check the arguments first */
ret = pfarg_is_sane(current, req);
if (ret < 0)
return ret;
ctx_flags = req->ctx_flags;
ret = -ENOMEM;
fd = get_unused_fd();
if (fd < 0)
return fd;
ctx = pfm_context_alloc(ctx_flags);
if (!ctx)
goto error;
filp = pfm_alloc_file(ctx);
if (IS_ERR(filp)) {
ret = PTR_ERR(filp);
goto error_file;
}
req->ctx_fd = ctx->ctx_fd = fd;
/*
* does the user want to sample?
*/
if (pfm_uuid_cmp(req->ctx_smpl_buf_id, pfm_null_uuid)) {
ret = pfm_setup_buffer_fmt(current, filp, ctx, ctx_flags, 0, req);
if (ret)
goto buffer_error;
}
DPRINT(("ctx=%p flags=0x%x system=%d notify_block=%d excl_idle=%d no_msg=%d ctx_fd=%d \n",
ctx,
ctx_flags,
ctx->ctx_fl_system,
ctx->ctx_fl_block,
ctx->ctx_fl_excl_idle,
ctx->ctx_fl_no_msg,
ctx->ctx_fd));
/*
* initialize soft PMU state
*/
pfm_reset_pmu_state(ctx);
fd_install(fd, filp);
return 0;
buffer_error:
path = filp->f_path;
put_filp(filp);
path_put(&path);
if (ctx->ctx_buf_fmt) {
pfm_buf_fmt_exit(ctx->ctx_buf_fmt, current, NULL, regs);
}
error_file:
pfm_context_free(ctx);
error:
put_unused_fd(fd);
return ret;
}
static inline unsigned long
pfm_new_counter_value (pfm_counter_t *reg, int is_long_reset)
{
unsigned long val = is_long_reset ? reg->long_reset : reg->short_reset;
unsigned long new_seed, old_seed = reg->seed, mask = reg->mask;
extern unsigned long carta_random32 (unsigned long seed);
if (reg->flags & PFM_REGFL_RANDOM) {
new_seed = carta_random32(old_seed);
val -= (old_seed & mask); /* counter values are negative numbers! */
if ((mask >> 32) != 0)
/* construct a full 64-bit random value: */
new_seed |= carta_random32(old_seed >> 32) << 32;
reg->seed = new_seed;
}
reg->lval = val;
return val;
}
static void
pfm_reset_regs_masked(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
{
unsigned long mask = ovfl_regs[0];
unsigned long reset_others = 0UL;
unsigned long val;
int i;
/*
* now restore reset value on sampling overflowed counters
*/
mask >>= PMU_FIRST_COUNTER;
for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
if ((mask & 0x1UL) == 0UL) continue;
ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
}
/*
* Now take care of resetting the other registers
*/
for(i = 0; reset_others; i++, reset_others >>= 1) {
if ((reset_others & 0x1) == 0) continue;
ctx->ctx_pmds[i].val = val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
is_long_reset ? "long" : "short", i, val));
}
}
static void
pfm_reset_regs(pfm_context_t *ctx, unsigned long *ovfl_regs, int is_long_reset)
{
unsigned long mask = ovfl_regs[0];
unsigned long reset_others = 0UL;
unsigned long val;
int i;
DPRINT_ovfl(("ovfl_regs=0x%lx is_long_reset=%d\n", ovfl_regs[0], is_long_reset));
if (ctx->ctx_state == PFM_CTX_MASKED) {
pfm_reset_regs_masked(ctx, ovfl_regs, is_long_reset);
return;
}
/*
* now restore reset value on sampling overflowed counters
*/
mask >>= PMU_FIRST_COUNTER;
for(i = PMU_FIRST_COUNTER; mask; i++, mask >>= 1) {
if ((mask & 0x1UL) == 0UL) continue;
val = pfm_new_counter_value(ctx->ctx_pmds+ i, is_long_reset);
reset_others |= ctx->ctx_pmds[i].reset_pmds[0];
DPRINT_ovfl((" %s reset ctx_pmds[%d]=%lx\n", is_long_reset ? "long" : "short", i, val));
pfm_write_soft_counter(ctx, i, val);
}
/*
* Now take care of resetting the other registers
*/
for(i = 0; reset_others; i++, reset_others >>= 1) {
if ((reset_others & 0x1) == 0) continue;
val = pfm_new_counter_value(ctx->ctx_pmds + i, is_long_reset);
if (PMD_IS_COUNTING(i)) {
pfm_write_soft_counter(ctx, i, val);
} else {
ia64_set_pmd(i, val);
}
DPRINT_ovfl(("%s reset_others pmd[%d]=%lx\n",
is_long_reset ? "long" : "short", i, val));
}
ia64_srlz_d();
}
static int
pfm_write_pmcs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned long value, pmc_pm;
unsigned long smpl_pmds, reset_pmds, impl_pmds;
unsigned int cnum, reg_flags, flags, pmc_type;
int i, can_access_pmu = 0, is_loaded, is_system, expert_mode;
int is_monitor, is_counting, state;
int ret = -EINVAL;
pfm_reg_check_t wr_func;
#define PFM_CHECK_PMC_PM(x, y, z) ((x)->ctx_fl_system ^ PMC_PM(y, z))
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
task = ctx->ctx_task;
impl_pmds = pmu_conf->impl_pmds[0];
if (state == PFM_CTX_ZOMBIE) return -EINVAL;
if (is_loaded) {
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
}
expert_mode = pfm_sysctl.expert_mode;
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
reg_flags = req->reg_flags;
value = req->reg_value;
smpl_pmds = req->reg_smpl_pmds[0];
reset_pmds = req->reg_reset_pmds[0];
flags = 0;
if (cnum >= PMU_MAX_PMCS) {
DPRINT(("pmc%u is invalid\n", cnum));
goto error;
}
pmc_type = pmu_conf->pmc_desc[cnum].type;
pmc_pm = (value >> pmu_conf->pmc_desc[cnum].pm_pos) & 0x1;
is_counting = (pmc_type & PFM_REG_COUNTING) == PFM_REG_COUNTING ? 1 : 0;
is_monitor = (pmc_type & PFM_REG_MONITOR) == PFM_REG_MONITOR ? 1 : 0;
/*
* we reject all non implemented PMC as well
* as attempts to modify PMC[0-3] which are used
* as status registers by the PMU
*/
if ((pmc_type & PFM_REG_IMPL) == 0 || (pmc_type & PFM_REG_CONTROL) == PFM_REG_CONTROL) {
DPRINT(("pmc%u is unimplemented or no-access pmc_type=%x\n", cnum, pmc_type));
goto error;
}
wr_func = pmu_conf->pmc_desc[cnum].write_check;
/*
* If the PMC is a monitor, then if the value is not the default:
* - system-wide session: PMCx.pm=1 (privileged monitor)
* - per-task : PMCx.pm=0 (user monitor)
*/
if (is_monitor && value != PMC_DFL_VAL(cnum) && is_system ^ pmc_pm) {
DPRINT(("pmc%u pmc_pm=%lu is_system=%d\n",
cnum,
pmc_pm,
is_system));
goto error;
}
if (is_counting) {
/*
* enforce generation of overflow interrupt. Necessary on all
* CPUs.
*/
value |= 1 << PMU_PMC_OI;
if (reg_flags & PFM_REGFL_OVFL_NOTIFY) {
flags |= PFM_REGFL_OVFL_NOTIFY;
}
if (reg_flags & PFM_REGFL_RANDOM) flags |= PFM_REGFL_RANDOM;
/* verify validity of smpl_pmds */
if ((smpl_pmds & impl_pmds) != smpl_pmds) {
DPRINT(("invalid smpl_pmds 0x%lx for pmc%u\n", smpl_pmds, cnum));
goto error;
}
/* verify validity of reset_pmds */
if ((reset_pmds & impl_pmds) != reset_pmds) {
DPRINT(("invalid reset_pmds 0x%lx for pmc%u\n", reset_pmds, cnum));
goto error;
}
} else {
if (reg_flags & (PFM_REGFL_OVFL_NOTIFY|PFM_REGFL_RANDOM)) {
DPRINT(("cannot set ovfl_notify or random on pmc%u\n", cnum));
goto error;
}
/* eventid on non-counting monitors are ignored */
}
/*
* execute write checker, if any
*/
if (likely(expert_mode == 0 && wr_func)) {
ret = (*wr_func)(task, ctx, cnum, &value, regs);
if (ret) goto error;
ret = -EINVAL;
}
/*
* no error on this register
*/
PFM_REG_RETFLAG_SET(req->reg_flags, 0);
/*
* Now we commit the changes to the software state
*/
/*
* update overflow information
*/
if (is_counting) {
/*
* full flag update each time a register is programmed
*/
ctx->ctx_pmds[cnum].flags = flags;
ctx->ctx_pmds[cnum].reset_pmds[0] = reset_pmds;
ctx->ctx_pmds[cnum].smpl_pmds[0] = smpl_pmds;
ctx->ctx_pmds[cnum].eventid = req->reg_smpl_eventid;
/*
* Mark all PMDS to be accessed as used.
*
* We do not keep track of PMC because we have to
* systematically restore ALL of them.
*
* We do not update the used_monitors mask, because
* if we have not programmed them, then will be in
* a quiescent state, therefore we will not need to
* mask/restore then when context is MASKED.
*/
CTX_USED_PMD(ctx, reset_pmds);
CTX_USED_PMD(ctx, smpl_pmds);
/*
* make sure we do not try to reset on
* restart because we have established new values
*/
if (state == PFM_CTX_MASKED) ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
}
/*
* Needed in case the user does not initialize the equivalent
* PMD. Clearing is done indirectly via pfm_reset_pmu_state() so there is no
* possible leak here.
*/
CTX_USED_PMD(ctx, pmu_conf->pmc_desc[cnum].dep_pmd[0]);
/*
* keep track of the monitor PMC that we are using.
* we save the value of the pmc in ctx_pmcs[] and if
* the monitoring is not stopped for the context we also
* place it in the saved state area so that it will be
* picked up later by the context switch code.
*
* The value in ctx_pmcs[] can only be changed in pfm_write_pmcs().
*
* The value in th_pmcs[] may be modified on overflow, i.e., when
* monitoring needs to be stopped.
*/
if (is_monitor) CTX_USED_MONITOR(ctx, 1UL << cnum);
/*
* update context state
*/
ctx->ctx_pmcs[cnum] = value;
if (is_loaded) {
/*
* write thread state
*/
if (is_system == 0) ctx->th_pmcs[cnum] = value;
/*
* write hardware register if we can
*/
if (can_access_pmu) {
ia64_set_pmc(cnum, value);
}
#ifdef CONFIG_SMP
else {
/*
* per-task SMP only here
*
* we are guaranteed that the task is not running on the other CPU,
* we indicate that this PMD will need to be reloaded if the task
* is rescheduled on the CPU it ran last on.
*/
ctx->ctx_reload_pmcs[0] |= 1UL << cnum;
}
#endif
}
DPRINT(("pmc[%u]=0x%lx ld=%d apmu=%d flags=0x%x all_pmcs=0x%lx used_pmds=0x%lx eventid=%ld smpl_pmds=0x%lx reset_pmds=0x%lx reloads_pmcs=0x%lx used_monitors=0x%lx ovfl_regs=0x%lx\n",
cnum,
value,
is_loaded,
can_access_pmu,
flags,
ctx->ctx_all_pmcs[0],
ctx->ctx_used_pmds[0],
ctx->ctx_pmds[cnum].eventid,
smpl_pmds,
reset_pmds,
ctx->ctx_reload_pmcs[0],
ctx->ctx_used_monitors[0],
ctx->ctx_ovfl_regs[0]));
}
/*
* make sure the changes are visible
*/
if (can_access_pmu) ia64_srlz_d();
return 0;
error:
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
static int
pfm_write_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned long value, hw_value, ovfl_mask;
unsigned int cnum;
int i, can_access_pmu = 0, state;
int is_counting, is_loaded, is_system, expert_mode;
int ret = -EINVAL;
pfm_reg_check_t wr_func;
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
ovfl_mask = pmu_conf->ovfl_val;
task = ctx->ctx_task;
if (unlikely(state == PFM_CTX_ZOMBIE)) return -EINVAL;
/*
* on both UP and SMP, we can only write to the PMC when the task is
* the owner of the local PMU.
*/
if (likely(is_loaded)) {
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
}
expert_mode = pfm_sysctl.expert_mode;
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
value = req->reg_value;
if (!PMD_IS_IMPL(cnum)) {
DPRINT(("pmd[%u] is unimplemented or invalid\n", cnum));
goto abort_mission;
}
is_counting = PMD_IS_COUNTING(cnum);
wr_func = pmu_conf->pmd_desc[cnum].write_check;
/*
* execute write checker, if any
*/
if (unlikely(expert_mode == 0 && wr_func)) {
unsigned long v = value;
ret = (*wr_func)(task, ctx, cnum, &v, regs);
if (ret) goto abort_mission;
value = v;
ret = -EINVAL;
}
/*
* no error on this register
*/
PFM_REG_RETFLAG_SET(req->reg_flags, 0);
/*
* now commit changes to software state
*/
hw_value = value;
/*
* update virtualized (64bits) counter
*/
if (is_counting) {
/*
* write context state
*/
ctx->ctx_pmds[cnum].lval = value;
/*
* when context is load we use the split value
*/
if (is_loaded) {
hw_value = value & ovfl_mask;
value = value & ~ovfl_mask;
}
}
/*
* update reset values (not just for counters)
*/
ctx->ctx_pmds[cnum].long_reset = req->reg_long_reset;
ctx->ctx_pmds[cnum].short_reset = req->reg_short_reset;
/*
* update randomization parameters (not just for counters)
*/
ctx->ctx_pmds[cnum].seed = req->reg_random_seed;
ctx->ctx_pmds[cnum].mask = req->reg_random_mask;
/*
* update context value
*/
ctx->ctx_pmds[cnum].val = value;
/*
* Keep track of what we use
*
* We do not keep track of PMC because we have to
* systematically restore ALL of them.
*/
CTX_USED_PMD(ctx, PMD_PMD_DEP(cnum));
/*
* mark this PMD register used as well
*/
CTX_USED_PMD(ctx, RDEP(cnum));
/*
* make sure we do not try to reset on
* restart because we have established new values
*/
if (is_counting && state == PFM_CTX_MASKED) {
ctx->ctx_ovfl_regs[0] &= ~1UL << cnum;
}
if (is_loaded) {
/*
* write thread state
*/
if (is_system == 0) ctx->th_pmds[cnum] = hw_value;
/*
* write hardware register if we can
*/
if (can_access_pmu) {
ia64_set_pmd(cnum, hw_value);
} else {
#ifdef CONFIG_SMP
/*
* we are guaranteed that the task is not running on the other CPU,
* we indicate that this PMD will need to be reloaded if the task
* is rescheduled on the CPU it ran last on.
*/
ctx->ctx_reload_pmds[0] |= 1UL << cnum;
#endif
}
}
DPRINT(("pmd[%u]=0x%lx ld=%d apmu=%d, hw_value=0x%lx ctx_pmd=0x%lx short_reset=0x%lx "
"long_reset=0x%lx notify=%c seed=0x%lx mask=0x%lx used_pmds=0x%lx reset_pmds=0x%lx reload_pmds=0x%lx all_pmds=0x%lx ovfl_regs=0x%lx\n",
cnum,
value,
is_loaded,
can_access_pmu,
hw_value,
ctx->ctx_pmds[cnum].val,
ctx->ctx_pmds[cnum].short_reset,
ctx->ctx_pmds[cnum].long_reset,
PMC_OVFL_NOTIFY(ctx, cnum) ? 'Y':'N',
ctx->ctx_pmds[cnum].seed,
ctx->ctx_pmds[cnum].mask,
ctx->ctx_used_pmds[0],
ctx->ctx_pmds[cnum].reset_pmds[0],
ctx->ctx_reload_pmds[0],
ctx->ctx_all_pmds[0],
ctx->ctx_ovfl_regs[0]));
}
/*
* make changes visible
*/
if (can_access_pmu) ia64_srlz_d();
return 0;
abort_mission:
/*
* for now, we have only one possibility for error
*/
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
/*
* By the way of PROTECT_CONTEXT(), interrupts are masked while we are in this function.
* Therefore we know, we do not have to worry about the PMU overflow interrupt. If an
* interrupt is delivered during the call, it will be kept pending until we leave, making
* it appears as if it had been generated at the UNPROTECT_CONTEXT(). At least we are
* guaranteed to return consistent data to the user, it may simply be old. It is not
* trivial to treat the overflow while inside the call because you may end up in
* some module sampling buffer code causing deadlocks.
*/
static int
pfm_read_pmds(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
unsigned long val = 0UL, lval, ovfl_mask, sval;
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned int cnum, reg_flags = 0;
int i, can_access_pmu = 0, state;
int is_loaded, is_system, is_counting, expert_mode;
int ret = -EINVAL;
pfm_reg_check_t rd_func;
/*
* access is possible when loaded only for
* self-monitoring tasks or in UP mode
*/
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
ovfl_mask = pmu_conf->ovfl_val;
task = ctx->ctx_task;
if (state == PFM_CTX_ZOMBIE) return -EINVAL;
if (likely(is_loaded)) {
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
/*
* this can be true when not self-monitoring only in UP
*/
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
if (can_access_pmu) ia64_srlz_d();
}
expert_mode = pfm_sysctl.expert_mode;
DPRINT(("ld=%d apmu=%d ctx_state=%d\n",
is_loaded,
can_access_pmu,
state));
/*
* on both UP and SMP, we can only read the PMD from the hardware register when
* the task is the owner of the local PMU.
*/
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
reg_flags = req->reg_flags;
if (unlikely(!PMD_IS_IMPL(cnum))) goto error;
/*
* we can only read the register that we use. That includes
* the one we explicitly initialize AND the one we want included
* in the sampling buffer (smpl_regs).
*
* Having this restriction allows optimization in the ctxsw routine
* without compromising security (leaks)
*/
if (unlikely(!CTX_IS_USED_PMD(ctx, cnum))) goto error;
sval = ctx->ctx_pmds[cnum].val;
lval = ctx->ctx_pmds[cnum].lval;
is_counting = PMD_IS_COUNTING(cnum);
/*
* If the task is not the current one, then we check if the
* PMU state is still in the local live register due to lazy ctxsw.
* If true, then we read directly from the registers.
*/
if (can_access_pmu){
val = ia64_get_pmd(cnum);
} else {
/*
* context has been saved
* if context is zombie, then task does not exist anymore.
* In this case, we use the full value saved in the context (pfm_flush_regs()).
*/
val = is_loaded ? ctx->th_pmds[cnum] : 0UL;
}
rd_func = pmu_conf->pmd_desc[cnum].read_check;
if (is_counting) {
/*
* XXX: need to check for overflow when loaded
*/
val &= ovfl_mask;
val += sval;
}
/*
* execute read checker, if any
*/
if (unlikely(expert_mode == 0 && rd_func)) {
unsigned long v = val;
ret = (*rd_func)(ctx->ctx_task, ctx, cnum, &v, regs);
if (ret) goto error;
val = v;
ret = -EINVAL;
}
PFM_REG_RETFLAG_SET(reg_flags, 0);
DPRINT(("pmd[%u]=0x%lx\n", cnum, val));
/*
* update register return value, abort all if problem during copy.
* we only modify the reg_flags field. no check mode is fine because
* access has been verified upfront in sys_perfmonctl().
*/
req->reg_value = val;
req->reg_flags = reg_flags;
req->reg_last_reset_val = lval;
}
return 0;
error:
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
int
pfm_mod_write_pmcs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_write_pmcs(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_write_pmcs);
int
pfm_mod_read_pmds(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_read_pmds(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_read_pmds);
/*
* Only call this function when a process it trying to
* write the debug registers (reading is always allowed)
*/
int
pfm_use_debug_registers(struct task_struct *task)
{
pfm_context_t *ctx = task->thread.pfm_context;
unsigned long flags;
int ret = 0;
if (pmu_conf->use_rr_dbregs == 0) return 0;
DPRINT(("called for [%d]\n", task_pid_nr(task)));
/*
* do it only once
*/
if (task->thread.flags & IA64_THREAD_DBG_VALID) return 0;
/*
* Even on SMP, we do not need to use an atomic here because
* the only way in is via ptrace() and this is possible only when the
* process is stopped. Even in the case where the ctxsw out is not totally
* completed by the time we come here, there is no way the 'stopped' process
* could be in the middle of fiddling with the pfm_write_ibr_dbr() routine.
* So this is always safe.
*/
if (ctx && ctx->ctx_fl_using_dbreg == 1) return -1;
LOCK_PFS(flags);
/*
* We cannot allow setting breakpoints when system wide monitoring
* sessions are using the debug registers.
*/
if (pfm_sessions.pfs_sys_use_dbregs> 0)
ret = -1;
else
pfm_sessions.pfs_ptrace_use_dbregs++;
DPRINT(("ptrace_use_dbregs=%u sys_use_dbregs=%u by [%d] ret = %d\n",
pfm_sessions.pfs_ptrace_use_dbregs,
pfm_sessions.pfs_sys_use_dbregs,
task_pid_nr(task), ret));
UNLOCK_PFS(flags);
return ret;
}
/*
* This function is called for every task that exits with the
* IA64_THREAD_DBG_VALID set. This indicates a task which was
* able to use the debug registers for debugging purposes via
* ptrace(). Therefore we know it was not using them for
* perfmormance monitoring, so we only decrement the number
* of "ptraced" debug register users to keep the count up to date
*/
int
pfm_release_debug_registers(struct task_struct *task)
{
unsigned long flags;
int ret;
if (pmu_conf->use_rr_dbregs == 0) return 0;
LOCK_PFS(flags);
if (pfm_sessions.pfs_ptrace_use_dbregs == 0) {
printk(KERN_ERR "perfmon: invalid release for [%d] ptrace_use_dbregs=0\n", task_pid_nr(task));
ret = -1;
} else {
pfm_sessions.pfs_ptrace_use_dbregs--;
ret = 0;
}
UNLOCK_PFS(flags);
return ret;
}
static int
pfm_restart(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
pfm_buffer_fmt_t *fmt;
pfm_ovfl_ctrl_t rst_ctrl;
int state, is_system;
int ret = 0;
state = ctx->ctx_state;
fmt = ctx->ctx_buf_fmt;
is_system = ctx->ctx_fl_system;
task = PFM_CTX_TASK(ctx);
switch(state) {
case PFM_CTX_MASKED:
break;
case PFM_CTX_LOADED:
if (CTX_HAS_SMPL(ctx) && fmt->fmt_restart_active) break;
/* fall through */
case PFM_CTX_UNLOADED:
case PFM_CTX_ZOMBIE:
DPRINT(("invalid state=%d\n", state));
return -EBUSY;
default:
DPRINT(("state=%d, cannot operate (no active_restart handler)\n", state));
return -EINVAL;
}
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
/* sanity check */
if (unlikely(task == NULL)) {
printk(KERN_ERR "perfmon: [%d] pfm_restart no task\n", task_pid_nr(current));
return -EINVAL;
}
if (task == current || is_system) {
fmt = ctx->ctx_buf_fmt;
DPRINT(("restarting self %d ovfl=0x%lx\n",
task_pid_nr(task),
ctx->ctx_ovfl_regs[0]));
if (CTX_HAS_SMPL(ctx)) {
prefetch(ctx->ctx_smpl_hdr);
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 0;
if (state == PFM_CTX_LOADED)
ret = pfm_buf_fmt_restart_active(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
else
ret = pfm_buf_fmt_restart(fmt, task, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
} else {
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 1;
}
if (ret == 0) {
if (rst_ctrl.bits.reset_ovfl_pmds)
pfm_reset_regs(ctx, ctx->ctx_ovfl_regs, PFM_PMD_LONG_RESET);
if (rst_ctrl.bits.mask_monitoring == 0) {
DPRINT(("resuming monitoring for [%d]\n", task_pid_nr(task)));
if (state == PFM_CTX_MASKED) pfm_restore_monitoring(task);
} else {
DPRINT(("keeping monitoring stopped for [%d]\n", task_pid_nr(task)));
// cannot use pfm_stop_monitoring(task, regs);
}
}
/*
* clear overflowed PMD mask to remove any stale information
*/
ctx->ctx_ovfl_regs[0] = 0UL;
/*
* back to LOADED state
*/
ctx->ctx_state = PFM_CTX_LOADED;
/*
* XXX: not really useful for self monitoring
*/
ctx->ctx_fl_can_restart = 0;
return 0;
}
/*
* restart another task
*/
/*
* When PFM_CTX_MASKED, we cannot issue a restart before the previous
* one is seen by the task.
*/
if (state == PFM_CTX_MASKED) {
if (ctx->ctx_fl_can_restart == 0) return -EINVAL;
/*
* will prevent subsequent restart before this one is
* seen by other task
*/
ctx->ctx_fl_can_restart = 0;
}
/*
* if blocking, then post the semaphore is PFM_CTX_MASKED, i.e.
* the task is blocked or on its way to block. That's the normal
* restart path. If the monitoring is not masked, then the task
* can be actively monitoring and we cannot directly intervene.
* Therefore we use the trap mechanism to catch the task and
* force it to reset the buffer/reset PMDs.
*
* if non-blocking, then we ensure that the task will go into
* pfm_handle_work() before returning to user mode.
*
* We cannot explicitly reset another task, it MUST always
* be done by the task itself. This works for system wide because
* the tool that is controlling the session is logically doing
* "self-monitoring".
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && state == PFM_CTX_MASKED) {
DPRINT(("unblocking [%d] \n", task_pid_nr(task)));
complete(&ctx->ctx_restart_done);
} else {
DPRINT(("[%d] armed exit trap\n", task_pid_nr(task)));
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_RESET;
PFM_SET_WORK_PENDING(task, 1);
tsk_set_notify_resume(task);
/*
* XXX: send reschedule if task runs on another CPU
*/
}
return 0;
}
static int
pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
unsigned int m = *(unsigned int *)arg;
pfm_sysctl.debug = m == 0 ? 0 : 1;
printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
if (m == 0) {
memset(pfm_stats, 0, sizeof(pfm_stats));
for(m=0; m < NR_CPUS; m++) pfm_stats[m].pfm_ovfl_intr_cycles_min = ~0UL;
}
return 0;
}
/*
* arg can be NULL and count can be zero for this function
*/
static int
pfm_write_ibr_dbr(int mode, pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct thread_struct *thread = NULL;
struct task_struct *task;
pfarg_dbreg_t *req = (pfarg_dbreg_t *)arg;
unsigned long flags;
dbreg_t dbreg;
unsigned int rnum;
int first_time;
int ret = 0, state;
int i, can_access_pmu = 0;
int is_system, is_loaded;
if (pmu_conf->use_rr_dbregs == 0) return -EINVAL;
state = ctx->ctx_state;
is_loaded = state == PFM_CTX_LOADED ? 1 : 0;
is_system = ctx->ctx_fl_system;
task = ctx->ctx_task;
if (state == PFM_CTX_ZOMBIE) return -EINVAL;
/*
* on both UP and SMP, we can only write to the PMC when the task is
* the owner of the local PMU.
*/
if (is_loaded) {
thread = &task->thread;
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (unlikely(is_system && ctx->ctx_cpu != smp_processor_id())) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
can_access_pmu = GET_PMU_OWNER() == task || is_system ? 1 : 0;
}
/*
* we do not need to check for ipsr.db because we do clear ibr.x, dbr.r, and dbr.w
* ensuring that no real breakpoint can be installed via this call.
*
* IMPORTANT: regs can be NULL in this function
*/
first_time = ctx->ctx_fl_using_dbreg == 0;
/*
* don't bother if we are loaded and task is being debugged
*/
if (is_loaded && (thread->flags & IA64_THREAD_DBG_VALID) != 0) {
DPRINT(("debug registers already in use for [%d]\n", task_pid_nr(task)));
return -EBUSY;
}
/*
* check for debug registers in system wide mode
*
* If though a check is done in pfm_context_load(),
* we must repeat it here, in case the registers are
* written after the context is loaded
*/
if (is_loaded) {
LOCK_PFS(flags);
if (first_time && is_system) {
if (pfm_sessions.pfs_ptrace_use_dbregs)
ret = -EBUSY;
else
pfm_sessions.pfs_sys_use_dbregs++;
}
UNLOCK_PFS(flags);
}
if (ret != 0) return ret;
/*
* mark ourself as user of the debug registers for
* perfmon purposes.
*/
ctx->ctx_fl_using_dbreg = 1;
/*
* clear hardware registers to make sure we don't
* pick up stale state.
*
* for a system wide session, we do not use
* thread.dbr, thread.ibr because this process
* never leaves the current CPU and the state
* is shared by all processes running on it
*/
if (first_time && can_access_pmu) {
DPRINT(("[%d] clearing ibrs, dbrs\n", task_pid_nr(task)));
for (i=0; i < pmu_conf->num_ibrs; i++) {
ia64_set_ibr(i, 0UL);
ia64_dv_serialize_instruction();
}
ia64_srlz_i();
for (i=0; i < pmu_conf->num_dbrs; i++) {
ia64_set_dbr(i, 0UL);
ia64_dv_serialize_data();
}
ia64_srlz_d();
}
/*
* Now install the values into the registers
*/
for (i = 0; i < count; i++, req++) {
rnum = req->dbreg_num;
dbreg.val = req->dbreg_value;
ret = -EINVAL;
if ((mode == PFM_CODE_RR && rnum >= PFM_NUM_IBRS) || ((mode == PFM_DATA_RR) && rnum >= PFM_NUM_DBRS)) {
DPRINT(("invalid register %u val=0x%lx mode=%d i=%d count=%d\n",
rnum, dbreg.val, mode, i, count));
goto abort_mission;
}
/*
* make sure we do not install enabled breakpoint
*/
if (rnum & 0x1) {
if (mode == PFM_CODE_RR)
dbreg.ibr.ibr_x = 0;
else
dbreg.dbr.dbr_r = dbreg.dbr.dbr_w = 0;
}
PFM_REG_RETFLAG_SET(req->dbreg_flags, 0);
/*
* Debug registers, just like PMC, can only be modified
* by a kernel call. Moreover, perfmon() access to those
* registers are centralized in this routine. The hardware
* does not modify the value of these registers, therefore,
* if we save them as they are written, we can avoid having
* to save them on context switch out. This is made possible
* by the fact that when perfmon uses debug registers, ptrace()
* won't be able to modify them concurrently.
*/
if (mode == PFM_CODE_RR) {
CTX_USED_IBR(ctx, rnum);
if (can_access_pmu) {
ia64_set_ibr(rnum, dbreg.val);
ia64_dv_serialize_instruction();
}
ctx->ctx_ibrs[rnum] = dbreg.val;
DPRINT(("write ibr%u=0x%lx used_ibrs=0x%x ld=%d apmu=%d\n",
rnum, dbreg.val, ctx->ctx_used_ibrs[0], is_loaded, can_access_pmu));
} else {
CTX_USED_DBR(ctx, rnum);
if (can_access_pmu) {
ia64_set_dbr(rnum, dbreg.val);
ia64_dv_serialize_data();
}
ctx->ctx_dbrs[rnum] = dbreg.val;
DPRINT(("write dbr%u=0x%lx used_dbrs=0x%x ld=%d apmu=%d\n",
rnum, dbreg.val, ctx->ctx_used_dbrs[0], is_loaded, can_access_pmu));
}
}
return 0;
abort_mission:
/*
* in case it was our first attempt, we undo the global modifications
*/
if (first_time) {
LOCK_PFS(flags);
if (ctx->ctx_fl_system) {
pfm_sessions.pfs_sys_use_dbregs--;
}
UNLOCK_PFS(flags);
ctx->ctx_fl_using_dbreg = 0;
}
/*
* install error return flag
*/
PFM_REG_RETFLAG_SET(req->dbreg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
static int
pfm_write_ibrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
return pfm_write_ibr_dbr(PFM_CODE_RR, ctx, arg, count, regs);
}
static int
pfm_write_dbrs(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
return pfm_write_ibr_dbr(PFM_DATA_RR, ctx, arg, count, regs);
}
int
pfm_mod_write_ibrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_write_ibrs(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_write_ibrs);
int
pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int nreq, struct pt_regs *regs)
{
pfm_context_t *ctx;
if (req == NULL) return -EINVAL;
ctx = GET_PMU_CTX();
if (ctx == NULL) return -EINVAL;
/*
* for now limit to current task, which is enough when calling
* from overflow handler
*/
if (task != current && ctx->ctx_fl_system == 0) return -EBUSY;
return pfm_write_dbrs(ctx, req, nreq, regs);
}
EXPORT_SYMBOL(pfm_mod_write_dbrs);
static int
pfm_get_features(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
pfarg_features_t *req = (pfarg_features_t *)arg;
req->ft_version = PFM_VERSION;
return 0;
}
static int
pfm_stop(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct pt_regs *tregs;
struct task_struct *task = PFM_CTX_TASK(ctx);
int state, is_system;
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
/*
* context must be attached to issue the stop command (includes LOADED,MASKED,ZOMBIE)
*/
if (state == PFM_CTX_UNLOADED) return -EINVAL;
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
DPRINT(("task [%d] ctx_state=%d is_system=%d\n",
task_pid_nr(PFM_CTX_TASK(ctx)),
state,
is_system));
/*
* in system mode, we need to update the PMU directly
* and the user level state of the caller, which may not
* necessarily be the creator of the context.
*/
if (is_system) {
/*
* Update local PMU first
*
* disable dcr pp
*/
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) & ~IA64_DCR_PP);
ia64_srlz_i();
/*
* update local cpuinfo
*/
PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
/*
* stop monitoring, does srlz.i
*/
pfm_clear_psr_pp();
/*
* stop monitoring in the caller
*/
ia64_psr(regs)->pp = 0;
return 0;
}
/*
* per-task mode
*/
if (task == current) {
/* stop monitoring at kernel level */
pfm_clear_psr_up();
/*
* stop monitoring at the user level
*/
ia64_psr(regs)->up = 0;
} else {
tregs = task_pt_regs(task);
/*
* stop monitoring at the user level
*/
ia64_psr(tregs)->up = 0;
/*
* monitoring disabled in kernel at next reschedule
*/
ctx->ctx_saved_psr_up = 0;
DPRINT(("task=[%d]\n", task_pid_nr(task)));
}
return 0;
}
static int
pfm_start(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct pt_regs *tregs;
int state, is_system;
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
if (state != PFM_CTX_LOADED) return -EINVAL;
/*
* In system wide and when the context is loaded, access can only happen
* when the caller is running on the CPU being monitored by the session.
* It does not have to be the owner (ctx_task) of the context per se.
*/
if (is_system && ctx->ctx_cpu != smp_processor_id()) {
DPRINT(("should be running on CPU%d\n", ctx->ctx_cpu));
return -EBUSY;
}
/*
* in system mode, we need to update the PMU directly
* and the user level state of the caller, which may not
* necessarily be the creator of the context.
*/
if (is_system) {
/*
* set user level psr.pp for the caller
*/
ia64_psr(regs)->pp = 1;
/*
* now update the local PMU and cpuinfo
*/
PFM_CPUINFO_SET(PFM_CPUINFO_DCR_PP);
/*
* start monitoring at kernel level
*/
pfm_set_psr_pp();
/* enable dcr pp */
ia64_setreg(_IA64_REG_CR_DCR, ia64_getreg(_IA64_REG_CR_DCR) | IA64_DCR_PP);
ia64_srlz_i();
return 0;
}
/*
* per-process mode
*/
if (ctx->ctx_task == current) {
/* start monitoring at kernel level */
pfm_set_psr_up();
/*
* activate monitoring at user level
*/
ia64_psr(regs)->up = 1;
} else {
tregs = task_pt_regs(ctx->ctx_task);
/*
* start monitoring at the kernel level the next
* time the task is scheduled
*/
ctx->ctx_saved_psr_up = IA64_PSR_UP;
/*
* activate monitoring at user level
*/
ia64_psr(tregs)->up = 1;
}
return 0;
}
static int
pfm_get_pmc_reset(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
pfarg_reg_t *req = (pfarg_reg_t *)arg;
unsigned int cnum;
int i;
int ret = -EINVAL;
for (i = 0; i < count; i++, req++) {
cnum = req->reg_num;
if (!PMC_IS_IMPL(cnum)) goto abort_mission;
req->reg_value = PMC_DFL_VAL(cnum);
PFM_REG_RETFLAG_SET(req->reg_flags, 0);
DPRINT(("pmc_reset_val pmc[%u]=0x%lx\n", cnum, req->reg_value));
}
return 0;
abort_mission:
PFM_REG_RETFLAG_SET(req->reg_flags, PFM_REG_RETFL_EINVAL);
return ret;
}
static int
pfm_check_task_exist(pfm_context_t *ctx)
{
struct task_struct *g, *t;
int ret = -ESRCH;
read_lock(&tasklist_lock);
do_each_thread (g, t) {
if (t->thread.pfm_context == ctx) {
ret = 0;
goto out;
}
} while_each_thread (g, t);
out:
read_unlock(&tasklist_lock);
DPRINT(("pfm_check_task_exist: ret=%d ctx=%p\n", ret, ctx));
return ret;
}
static int
pfm_context_load(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task;
struct thread_struct *thread;
struct pfm_context_t *old;
unsigned long flags;
#ifndef CONFIG_SMP
struct task_struct *owner_task = NULL;
#endif
pfarg_load_t *req = (pfarg_load_t *)arg;
unsigned long *pmcs_source, *pmds_source;
int the_cpu;
int ret = 0;
int state, is_system, set_dbregs = 0;
state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
/*
* can only load from unloaded or terminated state
*/
if (state != PFM_CTX_UNLOADED) {
DPRINT(("cannot load to [%d], invalid ctx_state=%d\n",
req->load_pid,
ctx->ctx_state));
return -EBUSY;
}
DPRINT(("load_pid [%d] using_dbreg=%d\n", req->load_pid, ctx->ctx_fl_using_dbreg));
if (CTX_OVFL_NOBLOCK(ctx) == 0 && req->load_pid == current->pid) {
DPRINT(("cannot use blocking mode on self\n"));
return -EINVAL;
}
ret = pfm_get_task(ctx, req->load_pid, &task);
if (ret) {
DPRINT(("load_pid [%d] get_task=%d\n", req->load_pid, ret));
return ret;
}
ret = -EINVAL;
/*
* system wide is self monitoring only
*/
if (is_system && task != current) {
DPRINT(("system wide is self monitoring only load_pid=%d\n",
req->load_pid));
goto error;
}
thread = &task->thread;
ret = 0;
/*
* cannot load a context which is using range restrictions,
* into a task that is being debugged.
*/
if (ctx->ctx_fl_using_dbreg) {
if (thread->flags & IA64_THREAD_DBG_VALID) {
ret = -EBUSY;
DPRINT(("load_pid [%d] task is debugged, cannot load range restrictions\n", req->load_pid));
goto error;
}
LOCK_PFS(flags);
if (is_system) {
if (pfm_sessions.pfs_ptrace_use_dbregs) {
DPRINT(("cannot load [%d] dbregs in use\n",
task_pid_nr(task)));
ret = -EBUSY;
} else {
pfm_sessions.pfs_sys_use_dbregs++;
DPRINT(("load [%d] increased sys_use_dbreg=%u\n", task_pid_nr(task), pfm_sessions.pfs_sys_use_dbregs));
set_dbregs = 1;
}
}
UNLOCK_PFS(flags);
if (ret) goto error;
}
/*
* SMP system-wide monitoring implies self-monitoring.
*
* The programming model expects the task to
* be pinned on a CPU throughout the session.
* Here we take note of the current CPU at the
* time the context is loaded. No call from
* another CPU will be allowed.
*
* The pinning via shed_setaffinity()
* must be done by the calling task prior
* to this call.
*
* systemwide: keep track of CPU this session is supposed to run on
*/
the_cpu = ctx->ctx_cpu = smp_processor_id();
ret = -EBUSY;
/*
* now reserve the session
*/
ret = pfm_reserve_session(current, is_system, the_cpu);
if (ret) goto error;
/*
* task is necessarily stopped at this point.
*
* If the previous context was zombie, then it got removed in
* pfm_save_regs(). Therefore we should not see it here.
* If we see a context, then this is an active context
*
* XXX: needs to be atomic
*/
DPRINT(("before cmpxchg() old_ctx=%p new_ctx=%p\n",
thread->pfm_context, ctx));
ret = -EBUSY;
old = ia64_cmpxchg(acq, &thread->pfm_context, NULL, ctx, sizeof(pfm_context_t *));
if (old != NULL) {
DPRINT(("load_pid [%d] already has a context\n", req->load_pid));
goto error_unres;
}
pfm_reset_msgq(ctx);
ctx->ctx_state = PFM_CTX_LOADED;
/*
* link context to task
*/
ctx->ctx_task = task;
if (is_system) {
/*
* we load as stopped
*/
PFM_CPUINFO_SET(PFM_CPUINFO_SYST_WIDE);
PFM_CPUINFO_CLEAR(PFM_CPUINFO_DCR_PP);
if (ctx->ctx_fl_excl_idle) PFM_CPUINFO_SET(PFM_CPUINFO_EXCL_IDLE);
} else {
thread->flags |= IA64_THREAD_PM_VALID;
}
/*
* propagate into thread-state
*/
pfm_copy_pmds(task, ctx);
pfm_copy_pmcs(task, ctx);
pmcs_source = ctx->th_pmcs;
pmds_source = ctx->th_pmds;
/*
* always the case for system-wide
*/
if (task == current) {
if (is_system == 0) {
/* allow user level control */
ia64_psr(regs)->sp = 0;
DPRINT(("clearing psr.sp for [%d]\n", task_pid_nr(task)));
SET_LAST_CPU(ctx, smp_processor_id());
INC_ACTIVATION();
SET_ACTIVATION(ctx);
#ifndef CONFIG_SMP
/*
* push the other task out, if any
*/
owner_task = GET_PMU_OWNER();
if (owner_task) pfm_lazy_save_regs(owner_task);
#endif
}
/*
* load all PMD from ctx to PMU (as opposed to thread state)
* restore all PMC from ctx to PMU
*/
pfm_restore_pmds(pmds_source, ctx->ctx_all_pmds[0]);
pfm_restore_pmcs(pmcs_source, ctx->ctx_all_pmcs[0]);
ctx->ctx_reload_pmcs[0] = 0UL;
ctx->ctx_reload_pmds[0] = 0UL;
/*
* guaranteed safe by earlier check against DBG_VALID
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* set new ownership
*/
SET_PMU_OWNER(task, ctx);
DPRINT(("context loaded on PMU for [%d]\n", task_pid_nr(task)));
} else {
/*
* when not current, task MUST be stopped, so this is safe
*/
regs = task_pt_regs(task);
/* force a full reload */
ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
SET_LAST_CPU(ctx, -1);
/* initial saved psr (stopped) */
ctx->ctx_saved_psr_up = 0UL;
ia64_psr(regs)->up = ia64_psr(regs)->pp = 0;
}
ret = 0;
error_unres:
if (ret) pfm_unreserve_session(ctx, ctx->ctx_fl_system, the_cpu);
error:
/*
* we must undo the dbregs setting (for system-wide)
*/
if (ret && set_dbregs) {
LOCK_PFS(flags);
pfm_sessions.pfs_sys_use_dbregs--;
UNLOCK_PFS(flags);
}
/*
* release task, there is now a link with the context
*/
if (is_system == 0 && task != current) {
pfm_put_task(task);
if (ret == 0) {
ret = pfm_check_task_exist(ctx);
if (ret) {
ctx->ctx_state = PFM_CTX_UNLOADED;
ctx->ctx_task = NULL;
}
}
}
return ret;
}
/*
* in this function, we do not need to increase the use count
* for the task via get_task_struct(), because we hold the
* context lock. If the task were to disappear while having
* a context attached, it would go through pfm_exit_thread()
* which also grabs the context lock and would therefore be blocked
* until we are here.
*/
static void pfm_flush_pmds(struct task_struct *, pfm_context_t *ctx);
static int
pfm_context_unload(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
{
struct task_struct *task = PFM_CTX_TASK(ctx);
struct pt_regs *tregs;
int prev_state, is_system;
int ret;
DPRINT(("ctx_state=%d task [%d]\n", ctx->ctx_state, task ? task_pid_nr(task) : -1));
prev_state = ctx->ctx_state;
is_system = ctx->ctx_fl_system;
/*
* unload only when necessary
*/
if (prev_state == PFM_CTX_UNLOADED) {
DPRINT(("ctx_state=%d, nothing to do\n", prev_state));
return 0;
}
/*
* clear psr and dcr bits
*/
ret = pfm_stop(ctx, NULL, 0, regs);
if (ret) return ret;
ctx->ctx_state = PFM_CTX_UNLOADED;
/*
* in system mode, we need to update the PMU directly
* and the user level state of the caller, which may not
* necessarily be the creator of the context.
*/
if (is_system) {
/*
* Update cpuinfo
*
* local PMU is taken care of in pfm_stop()
*/
PFM_CPUINFO_CLEAR(PFM_CPUINFO_SYST_WIDE);
PFM_CPUINFO_CLEAR(PFM_CPUINFO_EXCL_IDLE);
/*
* save PMDs in context
* release ownership
*/
pfm_flush_pmds(current, ctx);
/*
* at this point we are done with the PMU
* so we can unreserve the resource.
*/
if (prev_state != PFM_CTX_ZOMBIE)
pfm_unreserve_session(ctx, 1 , ctx->ctx_cpu);
/*
* disconnect context from task
*/
task->thread.pfm_context = NULL;
/*
* disconnect task from context
*/
ctx->ctx_task = NULL;
/*
* There is nothing more to cleanup here.
*/
return 0;
}
/*
* per-task mode
*/
tregs = task == current ? regs : task_pt_regs(task);
if (task == current) {
/*
* cancel user level control
*/
ia64_psr(regs)->sp = 1;
DPRINT(("setting psr.sp for [%d]\n", task_pid_nr(task)));
}
/*
* save PMDs to context
* release ownership
*/
pfm_flush_pmds(task, ctx);
/*
* at this point we are done with the PMU
* so we can unreserve the resource.
*
* when state was ZOMBIE, we have already unreserved.
*/
if (prev_state != PFM_CTX_ZOMBIE)
pfm_unreserve_session(ctx, 0 , ctx->ctx_cpu);
/*
* reset activation counter and psr
*/
ctx->ctx_last_activation = PFM_INVALID_ACTIVATION;
SET_LAST_CPU(ctx, -1);
/*
* PMU state will not be restored
*/
task->thread.flags &= ~IA64_THREAD_PM_VALID;
/*
* break links between context and task
*/
task->thread.pfm_context = NULL;
ctx->ctx_task = NULL;
PFM_SET_WORK_PENDING(task, 0);
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
ctx->ctx_fl_can_restart = 0;
ctx->ctx_fl_going_zombie = 0;
DPRINT(("disconnected [%d] from context\n", task_pid_nr(task)));
return 0;
}
/*
* called only from exit_thread(): task == current
* we come here only if current has a context attached (loaded or masked)
*/
void
pfm_exit_thread(struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long flags;
struct pt_regs *regs = task_pt_regs(task);
int ret, state;
int free_ok = 0;
ctx = PFM_GET_CTX(task);
PROTECT_CTX(ctx, flags);
DPRINT(("state=%d task [%d]\n", ctx->ctx_state, task_pid_nr(task)));
state = ctx->ctx_state;
switch(state) {
case PFM_CTX_UNLOADED:
/*
* only comes to this function if pfm_context is not NULL, i.e., cannot
* be in unloaded state
*/
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] ctx unloaded\n", task_pid_nr(task));
break;
case PFM_CTX_LOADED:
case PFM_CTX_MASKED:
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
}
DPRINT(("ctx unloaded for current state was %d\n", state));
pfm_end_notify_user(ctx);
break;
case PFM_CTX_ZOMBIE:
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] state=%d unload failed %d\n", task_pid_nr(task), state, ret);
}
free_ok = 1;
break;
default:
printk(KERN_ERR "perfmon: pfm_exit_thread [%d] unexpected state=%d\n", task_pid_nr(task), state);
break;
}
UNPROTECT_CTX(ctx, flags);
{ u64 psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
BUG_ON(GET_PMU_OWNER());
BUG_ON(ia64_psr(regs)->up);
BUG_ON(ia64_psr(regs)->pp);
}
/*
* All memory free operations (especially for vmalloc'ed memory)
* MUST be done with interrupts ENABLED.
*/
if (free_ok) pfm_context_free(ctx);
}
/*
* functions MUST be listed in the increasing order of their index (see permfon.h)
*/
#define PFM_CMD(name, flags, arg_count, arg_type, getsz) { name, #name, flags, arg_count, sizeof(arg_type), getsz }
#define PFM_CMD_S(name, flags) { name, #name, flags, 0, 0, NULL }
#define PFM_CMD_PCLRWS (PFM_CMD_FD|PFM_CMD_ARG_RW|PFM_CMD_STOP)
#define PFM_CMD_PCLRW (PFM_CMD_FD|PFM_CMD_ARG_RW)
#define PFM_CMD_NONE { NULL, "no-cmd", 0, 0, 0, NULL}
static pfm_cmd_desc_t pfm_cmd_tab[]={
/* 0 */PFM_CMD_NONE,
/* 1 */PFM_CMD(pfm_write_pmcs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 2 */PFM_CMD(pfm_write_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 3 */PFM_CMD(pfm_read_pmds, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 4 */PFM_CMD_S(pfm_stop, PFM_CMD_PCLRWS),
/* 5 */PFM_CMD_S(pfm_start, PFM_CMD_PCLRWS),
/* 6 */PFM_CMD_NONE,
/* 7 */PFM_CMD_NONE,
/* 8 */PFM_CMD(pfm_context_create, PFM_CMD_ARG_RW, 1, pfarg_context_t, pfm_ctx_getsize),
/* 9 */PFM_CMD_NONE,
/* 10 */PFM_CMD_S(pfm_restart, PFM_CMD_PCLRW),
/* 11 */PFM_CMD_NONE,
/* 12 */PFM_CMD(pfm_get_features, PFM_CMD_ARG_RW, 1, pfarg_features_t, NULL),
/* 13 */PFM_CMD(pfm_debug, 0, 1, unsigned int, NULL),
/* 14 */PFM_CMD_NONE,
/* 15 */PFM_CMD(pfm_get_pmc_reset, PFM_CMD_ARG_RW, PFM_CMD_ARG_MANY, pfarg_reg_t, NULL),
/* 16 */PFM_CMD(pfm_context_load, PFM_CMD_PCLRWS, 1, pfarg_load_t, NULL),
/* 17 */PFM_CMD_S(pfm_context_unload, PFM_CMD_PCLRWS),
/* 18 */PFM_CMD_NONE,
/* 19 */PFM_CMD_NONE,
/* 20 */PFM_CMD_NONE,
/* 21 */PFM_CMD_NONE,
/* 22 */PFM_CMD_NONE,
/* 23 */PFM_CMD_NONE,
/* 24 */PFM_CMD_NONE,
/* 25 */PFM_CMD_NONE,
/* 26 */PFM_CMD_NONE,
/* 27 */PFM_CMD_NONE,
/* 28 */PFM_CMD_NONE,
/* 29 */PFM_CMD_NONE,
/* 30 */PFM_CMD_NONE,
/* 31 */PFM_CMD_NONE,
/* 32 */PFM_CMD(pfm_write_ibrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL),
/* 33 */PFM_CMD(pfm_write_dbrs, PFM_CMD_PCLRWS, PFM_CMD_ARG_MANY, pfarg_dbreg_t, NULL)
};
#define PFM_CMD_COUNT (sizeof(pfm_cmd_tab)/sizeof(pfm_cmd_desc_t))
static int
pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
{
struct task_struct *task;
int state, old_state;
recheck:
state = ctx->ctx_state;
task = ctx->ctx_task;
if (task == NULL) {
DPRINT(("context %d no task, state=%d\n", ctx->ctx_fd, state));
return 0;
}
DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
ctx->ctx_fd,
state,
task_pid_nr(task),
task->state, PFM_CMD_STOPPED(cmd)));
/*
* self-monitoring always ok.
*
* for system-wide the caller can either be the creator of the
* context (to one to which the context is attached to) OR
* a task running on the same CPU as the session.
*/
if (task == current || ctx->ctx_fl_system) return 0;
/*
* we are monitoring another thread
*/
switch(state) {
case PFM_CTX_UNLOADED:
/*
* if context is UNLOADED we are safe to go
*/
return 0;
case PFM_CTX_ZOMBIE:
/*
* no command can operate on a zombie context
*/
DPRINT(("cmd %d state zombie cannot operate on context\n", cmd));
return -EINVAL;
case PFM_CTX_MASKED:
/*
* PMU state has been saved to software even though
* the thread may still be running.
*/
if (cmd != PFM_UNLOAD_CONTEXT) return 0;
}
/*
* context is LOADED or MASKED. Some commands may need to have
* the task stopped.
*
* We could lift this restriction for UP but it would mean that
* the user has no guarantee the task would not run between
* two successive calls to perfmonctl(). That's probably OK.
* If this user wants to ensure the task does not run, then
* the task must be stopped.
*/
if (PFM_CMD_STOPPED(cmd)) {
if (!task_is_stopped_or_traced(task)) {
DPRINT(("[%d] task not in stopped state\n", task_pid_nr(task)));
return -EBUSY;
}
/*
* task is now stopped, wait for ctxsw out
*
* This is an interesting point in the code.
* We need to unprotect the context because
* the pfm_save_regs() routines needs to grab
* the same lock. There are danger in doing
* this because it leaves a window open for
* another task to get access to the context
* and possibly change its state. The one thing
* that is not possible is for the context to disappear
* because we are protected by the VFS layer, i.e.,
* get_fd()/put_fd().
*/
old_state = state;
UNPROTECT_CTX(ctx, flags);
wait_task_inactive(task);
PROTECT_CTX(ctx, flags);
/*
* we must recheck to verify if state has changed
*/
if (ctx->ctx_state != old_state) {
DPRINT(("old_state=%d new_state=%d\n", old_state, ctx->ctx_state));
goto recheck;
}
}
return 0;
}
/*
* system-call entry point (must return long)
*/
asmlinkage long
sys_perfmonctl (int fd, int cmd, void __user *arg, int count)
{
struct file *file = NULL;
pfm_context_t *ctx = NULL;
unsigned long flags = 0UL;
void *args_k = NULL;
long ret; /* will expand int return types */
size_t base_sz, sz, xtra_sz = 0;
int narg, completed_args = 0, call_made = 0, cmd_flags;
int (*func)(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs);
int (*getsize)(void *arg, size_t *sz);
#define PFM_MAX_ARGSIZE 4096
/*
* reject any call if perfmon was disabled at initialization
*/
if (unlikely(pmu_conf == NULL)) return -ENOSYS;
if (unlikely(cmd < 0 || cmd >= PFM_CMD_COUNT)) {
DPRINT(("invalid cmd=%d\n", cmd));
return -EINVAL;
}
func = pfm_cmd_tab[cmd].cmd_func;
narg = pfm_cmd_tab[cmd].cmd_narg;
base_sz = pfm_cmd_tab[cmd].cmd_argsize;
getsize = pfm_cmd_tab[cmd].cmd_getsize;
cmd_flags = pfm_cmd_tab[cmd].cmd_flags;
if (unlikely(func == NULL)) {
DPRINT(("invalid cmd=%d\n", cmd));
return -EINVAL;
}
DPRINT(("cmd=%s idx=%d narg=0x%x argsz=%lu count=%d\n",
PFM_CMD_NAME(cmd),
cmd,
narg,
base_sz,
count));
/*
* check if number of arguments matches what the command expects
*/
if (unlikely((narg == PFM_CMD_ARG_MANY && count <= 0) || (narg > 0 && narg != count)))
return -EINVAL;
restart_args:
sz = xtra_sz + base_sz*count;
/*
* limit abuse to min page size
*/
if (unlikely(sz > PFM_MAX_ARGSIZE)) {
printk(KERN_ERR "perfmon: [%d] argument too big %lu\n", task_pid_nr(current), sz);
return -E2BIG;
}
/*
* allocate default-sized argument buffer
*/
if (likely(count && args_k == NULL)) {
args_k = kmalloc(PFM_MAX_ARGSIZE, GFP_KERNEL);
if (args_k == NULL) return -ENOMEM;
}
ret = -EFAULT;
/*
* copy arguments
*
* assume sz = 0 for command without parameters
*/
if (sz && copy_from_user(args_k, arg, sz)) {
DPRINT(("cannot copy_from_user %lu bytes @%p\n", sz, arg));
goto error_args;
}
/*
* check if command supports extra parameters
*/
if (completed_args == 0 && getsize) {
/*
* get extra parameters size (based on main argument)
*/
ret = (*getsize)(args_k, &xtra_sz);
if (ret) goto error_args;
completed_args = 1;
DPRINT(("restart_args sz=%lu xtra_sz=%lu\n", sz, xtra_sz));
/* retry if necessary */
if (likely(xtra_sz)) goto restart_args;
}
if (unlikely((cmd_flags & PFM_CMD_FD) == 0)) goto skip_fd;
ret = -EBADF;
file = fget(fd);
if (unlikely(file == NULL)) {
DPRINT(("invalid fd %d\n", fd));
goto error_args;
}
if (unlikely(PFM_IS_FILE(file) == 0)) {
DPRINT(("fd %d not related to perfmon\n", fd));
goto error_args;
}
ctx = (pfm_context_t *)file->private_data;
if (unlikely(ctx == NULL)) {
DPRINT(("no context for fd %d\n", fd));
goto error_args;
}
prefetch(&ctx->ctx_state);
PROTECT_CTX(ctx, flags);
/*
* check task is stopped
*/
ret = pfm_check_task_state(ctx, cmd, flags);
if (unlikely(ret)) goto abort_locked;
skip_fd:
ret = (*func)(ctx, args_k, count, task_pt_regs(current));
call_made = 1;
abort_locked:
if (likely(ctx)) {
DPRINT(("context unlocked\n"));
UNPROTECT_CTX(ctx, flags);
}
/* copy argument back to user, if needed */
if (call_made && PFM_CMD_RW_ARG(cmd) && copy_to_user(arg, args_k, base_sz*count)) ret = -EFAULT;
error_args:
if (file)
fput(file);
kfree(args_k);
DPRINT(("cmd=%s ret=%ld\n", PFM_CMD_NAME(cmd), ret));
return ret;
}
static void
pfm_resume_after_ovfl(pfm_context_t *ctx, unsigned long ovfl_regs, struct pt_regs *regs)
{
pfm_buffer_fmt_t *fmt = ctx->ctx_buf_fmt;
pfm_ovfl_ctrl_t rst_ctrl;
int state;
int ret = 0;
state = ctx->ctx_state;
/*
* Unlock sampling buffer and reset index atomically
* XXX: not really needed when blocking
*/
if (CTX_HAS_SMPL(ctx)) {
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 0;
if (state == PFM_CTX_LOADED)
ret = pfm_buf_fmt_restart_active(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
else
ret = pfm_buf_fmt_restart(fmt, current, &rst_ctrl, ctx->ctx_smpl_hdr, regs);
} else {
rst_ctrl.bits.mask_monitoring = 0;
rst_ctrl.bits.reset_ovfl_pmds = 1;
}
if (ret == 0) {
if (rst_ctrl.bits.reset_ovfl_pmds) {
pfm_reset_regs(ctx, &ovfl_regs, PFM_PMD_LONG_RESET);
}
if (rst_ctrl.bits.mask_monitoring == 0) {
DPRINT(("resuming monitoring\n"));
if (ctx->ctx_state == PFM_CTX_MASKED) pfm_restore_monitoring(current);
} else {
DPRINT(("stopping monitoring\n"));
//pfm_stop_monitoring(current, regs);
}
ctx->ctx_state = PFM_CTX_LOADED;
}
}
/*
* context MUST BE LOCKED when calling
* can only be called for current
*/
static void
pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
{
int ret;
DPRINT(("entering for [%d]\n", task_pid_nr(current)));
ret = pfm_context_unload(ctx, NULL, 0, regs);
if (ret) {
printk(KERN_ERR "pfm_context_force_terminate: [%d] unloaded failed with %d\n", task_pid_nr(current), ret);
}
/*
* and wakeup controlling task, indicating we are now disconnected
*/
wake_up_interruptible(&ctx->ctx_zombieq);
/*
* given that context is still locked, the controlling
* task will only get access when we return from
* pfm_handle_work().
*/
}
static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
/*
* pfm_handle_work() can be called with interrupts enabled
* (TIF_NEED_RESCHED) or disabled. The down_interruptible
* call may sleep, therefore we must re-enable interrupts
* to avoid deadlocks. It is safe to do so because this function
* is called ONLY when returning to user level (pUStk=1), in which case
* there is no risk of kernel stack overflow due to deep
* interrupt nesting.
*/
void
pfm_handle_work(void)
{
pfm_context_t *ctx;
struct pt_regs *regs;
unsigned long flags, dummy_flags;
unsigned long ovfl_regs;
unsigned int reason;
int ret;
ctx = PFM_GET_CTX(current);
if (ctx == NULL) {
printk(KERN_ERR "perfmon: [%d] has no PFM context\n",
task_pid_nr(current));
return;
}
PROTECT_CTX(ctx, flags);
PFM_SET_WORK_PENDING(current, 0);
tsk_clear_notify_resume(current);
regs = task_pt_regs(current);
/*
* extract reason for being here and clear
*/
reason = ctx->ctx_fl_trap_reason;
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_NONE;
ovfl_regs = ctx->ctx_ovfl_regs[0];
DPRINT(("reason=%d state=%d\n", reason, ctx->ctx_state));
/*
* must be done before we check for simple-reset mode
*/
if (ctx->ctx_fl_going_zombie || ctx->ctx_state == PFM_CTX_ZOMBIE)
goto do_zombie;
//if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
if (reason == PFM_TRAP_REASON_RESET)
goto skip_blocking;
/*
* restore interrupt mask to what it was on entry.
* Could be enabled/diasbled.
*/
UNPROTECT_CTX(ctx, flags);
/*
* force interrupt enable because of down_interruptible()
*/
local_irq_enable();
DPRINT(("before block sleeping\n"));
/*
* may go through without blocking on SMP systems
* if restart has been received already by the time we call down()
*/
ret = wait_for_completion_interruptible(&ctx->ctx_restart_done);
DPRINT(("after block sleeping ret=%d\n", ret));
/*
* lock context and mask interrupts again
* We save flags into a dummy because we may have
* altered interrupts mask compared to entry in this
* function.
*/
PROTECT_CTX(ctx, dummy_flags);
/*
* we need to read the ovfl_regs only after wake-up
* because we may have had pfm_write_pmds() in between
* and that can changed PMD values and therefore
* ovfl_regs is reset for these new PMD values.
*/
ovfl_regs = ctx->ctx_ovfl_regs[0];
if (ctx->ctx_fl_going_zombie) {
do_zombie:
DPRINT(("context is zombie, bailing out\n"));
pfm_context_force_terminate(ctx, regs);
goto nothing_to_do;
}
/*
* in case of interruption of down() we don't restart anything
*/
if (ret < 0)
goto nothing_to_do;
skip_blocking:
pfm_resume_after_ovfl(ctx, ovfl_regs, regs);
ctx->ctx_ovfl_regs[0] = 0UL;
nothing_to_do:
/*
* restore flags as they were upon entry
*/
UNPROTECT_CTX(ctx, flags);
}
static int
pfm_notify_user(pfm_context_t *ctx, pfm_msg_t *msg)
{
if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
DPRINT(("ignoring overflow notification, owner is zombie\n"));
return 0;
}
DPRINT(("waking up somebody\n"));
if (msg) wake_up_interruptible(&ctx->ctx_msgq_wait);
/*
* safe, we are not in intr handler, nor in ctxsw when
* we come here
*/
kill_fasync (&ctx->ctx_async_queue, SIGIO, POLL_IN);
return 0;
}
static int
pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds)
{
pfm_msg_t *msg = NULL;
if (ctx->ctx_fl_no_msg == 0) {
msg = pfm_get_new_msg(ctx);
if (msg == NULL) {
printk(KERN_ERR "perfmon: pfm_ovfl_notify_user no more notification msgs\n");
return -1;
}
msg->pfm_ovfl_msg.msg_type = PFM_MSG_OVFL;
msg->pfm_ovfl_msg.msg_ctx_fd = ctx->ctx_fd;
msg->pfm_ovfl_msg.msg_active_set = 0;
msg->pfm_ovfl_msg.msg_ovfl_pmds[0] = ovfl_pmds;
msg->pfm_ovfl_msg.msg_ovfl_pmds[1] = 0UL;
msg->pfm_ovfl_msg.msg_ovfl_pmds[2] = 0UL;
msg->pfm_ovfl_msg.msg_ovfl_pmds[3] = 0UL;
msg->pfm_ovfl_msg.msg_tstamp = 0UL;
}
DPRINT(("ovfl msg: msg=%p no_msg=%d fd=%d ovfl_pmds=0x%lx\n",
msg,
ctx->ctx_fl_no_msg,
ctx->ctx_fd,
ovfl_pmds));
return pfm_notify_user(ctx, msg);
}
static int
pfm_end_notify_user(pfm_context_t *ctx)
{
pfm_msg_t *msg;
msg = pfm_get_new_msg(ctx);
if (msg == NULL) {
printk(KERN_ERR "perfmon: pfm_end_notify_user no more notification msgs\n");
return -1;
}
/* no leak */
memset(msg, 0, sizeof(*msg));
msg->pfm_end_msg.msg_type = PFM_MSG_END;
msg->pfm_end_msg.msg_ctx_fd = ctx->ctx_fd;
msg->pfm_ovfl_msg.msg_tstamp = 0UL;
DPRINT(("end msg: msg=%p no_msg=%d ctx_fd=%d\n",
msg,
ctx->ctx_fl_no_msg,
ctx->ctx_fd));
return pfm_notify_user(ctx, msg);
}
/*
* main overflow processing routine.
* it can be called from the interrupt path or explicitly during the context switch code
*/
static void
pfm_overflow_handler(struct task_struct *task, pfm_context_t *ctx, u64 pmc0, struct pt_regs *regs)
{
pfm_ovfl_arg_t *ovfl_arg;
unsigned long mask;
unsigned long old_val, ovfl_val, new_val;
unsigned long ovfl_notify = 0UL, ovfl_pmds = 0UL, smpl_pmds = 0UL, reset_pmds;
unsigned long tstamp;
pfm_ovfl_ctrl_t ovfl_ctrl;
unsigned int i, has_smpl;
int must_notify = 0;
if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) goto stop_monitoring;
/*
* sanity test. Should never happen
*/
if (unlikely((pmc0 & 0x1) == 0)) goto sanity_check;
tstamp = ia64_get_itc();
mask = pmc0 >> PMU_FIRST_COUNTER;
ovfl_val = pmu_conf->ovfl_val;
has_smpl = CTX_HAS_SMPL(ctx);
DPRINT_ovfl(("pmc0=0x%lx pid=%d iip=0x%lx, %s "
"used_pmds=0x%lx\n",
pmc0,
task ? task_pid_nr(task): -1,
(regs ? regs->cr_iip : 0),
CTX_OVFL_NOBLOCK(ctx) ? "nonblocking" : "blocking",
ctx->ctx_used_pmds[0]));
/*
* first we update the virtual counters
* assume there was a prior ia64_srlz_d() issued
*/
for (i = PMU_FIRST_COUNTER; mask ; i++, mask >>= 1) {
/* skip pmd which did not overflow */
if ((mask & 0x1) == 0) continue;
/*
* Note that the pmd is not necessarily 0 at this point as qualified events
* may have happened before the PMU was frozen. The residual count is not
* taken into consideration here but will be with any read of the pmd via
* pfm_read_pmds().
*/
old_val = new_val = ctx->ctx_pmds[i].val;
new_val += 1 + ovfl_val;
ctx->ctx_pmds[i].val = new_val;
/*
* check for overflow condition
*/
if (likely(old_val > new_val)) {
ovfl_pmds |= 1UL << i;
if (PMC_OVFL_NOTIFY(ctx, i)) ovfl_notify |= 1UL << i;
}
DPRINT_ovfl(("ctx_pmd[%d].val=0x%lx old_val=0x%lx pmd=0x%lx ovfl_pmds=0x%lx ovfl_notify=0x%lx\n",
i,
new_val,
old_val,
ia64_get_pmd(i) & ovfl_val,
ovfl_pmds,
ovfl_notify));
}
/*
* there was no 64-bit overflow, nothing else to do
*/
if (ovfl_pmds == 0UL) return;
/*
* reset all control bits
*/
ovfl_ctrl.val = 0;
reset_pmds = 0UL;
/*
* if a sampling format module exists, then we "cache" the overflow by
* calling the module's handler() routine.
*/
if (has_smpl) {
unsigned long start_cycles, end_cycles;
unsigned long pmd_mask;
int j, k, ret = 0;
int this_cpu = smp_processor_id();
pmd_mask = ovfl_pmds >> PMU_FIRST_COUNTER;
ovfl_arg = &ctx->ctx_ovfl_arg;
prefetch(ctx->ctx_smpl_hdr);
for(i=PMU_FIRST_COUNTER; pmd_mask && ret == 0; i++, pmd_mask >>=1) {
mask = 1UL << i;
if ((pmd_mask & 0x1) == 0) continue;
ovfl_arg->ovfl_pmd = (unsigned char )i;
ovfl_arg->ovfl_notify = ovfl_notify & mask ? 1 : 0;
ovfl_arg->active_set = 0;
ovfl_arg->ovfl_ctrl.val = 0; /* module must fill in all fields */
ovfl_arg->smpl_pmds[0] = smpl_pmds = ctx->ctx_pmds[i].smpl_pmds[0];
ovfl_arg->pmd_value = ctx->ctx_pmds[i].val;
ovfl_arg->pmd_last_reset = ctx->ctx_pmds[i].lval;
ovfl_arg->pmd_eventid = ctx->ctx_pmds[i].eventid;
/*
* copy values of pmds of interest. Sampling format may copy them
* into sampling buffer.
*/
if (smpl_pmds) {
for(j=0, k=0; smpl_pmds; j++, smpl_pmds >>=1) {
if ((smpl_pmds & 0x1) == 0) continue;
ovfl_arg->smpl_pmds_values[k++] = PMD_IS_COUNTING(j) ? pfm_read_soft_counter(ctx, j) : ia64_get_pmd(j);
DPRINT_ovfl(("smpl_pmd[%d]=pmd%u=0x%lx\n", k-1, j, ovfl_arg->smpl_pmds_values[k-1]));
}
}
pfm_stats[this_cpu].pfm_smpl_handler_calls++;
start_cycles = ia64_get_itc();
/*
* call custom buffer format record (handler) routine
*/
ret = (*ctx->ctx_buf_fmt->fmt_handler)(task, ctx->ctx_smpl_hdr, ovfl_arg, regs, tstamp);
end_cycles = ia64_get_itc();
/*
* For those controls, we take the union because they have
* an all or nothing behavior.
*/
ovfl_ctrl.bits.notify_user |= ovfl_arg->ovfl_ctrl.bits.notify_user;
ovfl_ctrl.bits.block_task |= ovfl_arg->ovfl_ctrl.bits.block_task;
ovfl_ctrl.bits.mask_monitoring |= ovfl_arg->ovfl_ctrl.bits.mask_monitoring;
/*
* build the bitmask of pmds to reset now
*/
if (ovfl_arg->ovfl_ctrl.bits.reset_ovfl_pmds) reset_pmds |= mask;
pfm_stats[this_cpu].pfm_smpl_handler_cycles += end_cycles - start_cycles;
}
/*
* when the module cannot handle the rest of the overflows, we abort right here
*/
if (ret && pmd_mask) {
DPRINT(("handler aborts leftover ovfl_pmds=0x%lx\n",
pmd_mask<<PMU_FIRST_COUNTER));
}
/*
* remove the pmds we reset now from the set of pmds to reset in pfm_restart()
*/
ovfl_pmds &= ~reset_pmds;
} else {
/*
* when no sampling module is used, then the default
* is to notify on overflow if requested by user
*/
ovfl_ctrl.bits.notify_user = ovfl_notify ? 1 : 0;
ovfl_ctrl.bits.block_task = ovfl_notify ? 1 : 0;
ovfl_ctrl.bits.mask_monitoring = ovfl_notify ? 1 : 0; /* XXX: change for saturation */
ovfl_ctrl.bits.reset_ovfl_pmds = ovfl_notify ? 0 : 1;
/*
* if needed, we reset all overflowed pmds
*/
if (ovfl_notify == 0) reset_pmds = ovfl_pmds;
}
DPRINT_ovfl(("ovfl_pmds=0x%lx reset_pmds=0x%lx\n", ovfl_pmds, reset_pmds));
/*
* reset the requested PMD registers using the short reset values
*/
if (reset_pmds) {
unsigned long bm = reset_pmds;
pfm_reset_regs(ctx, &bm, PFM_PMD_SHORT_RESET);
}
if (ovfl_notify && ovfl_ctrl.bits.notify_user) {
/*
* keep track of what to reset when unblocking
*/
ctx->ctx_ovfl_regs[0] = ovfl_pmds;
/*
* check for blocking context
*/
if (CTX_OVFL_NOBLOCK(ctx) == 0 && ovfl_ctrl.bits.block_task) {
ctx->ctx_fl_trap_reason = PFM_TRAP_REASON_BLOCK;
/*
* set the perfmon specific checking pending work for the task
*/
PFM_SET_WORK_PENDING(task, 1);
/*
* when coming from ctxsw, current still points to the
* previous task, therefore we must work with task and not current.
*/
tsk_set_notify_resume(task);
}
/*
* defer until state is changed (shorten spin window). the context is locked
* anyway, so the signal receiver would come spin for nothing.
*/
must_notify = 1;
}
DPRINT_ovfl(("owner [%d] pending=%ld reason=%u ovfl_pmds=0x%lx ovfl_notify=0x%lx masked=%d\n",
GET_PMU_OWNER() ? task_pid_nr(GET_PMU_OWNER()) : -1,
PFM_GET_WORK_PENDING(task),
ctx->ctx_fl_trap_reason,
ovfl_pmds,
ovfl_notify,
ovfl_ctrl.bits.mask_monitoring ? 1 : 0));
/*
* in case monitoring must be stopped, we toggle the psr bits
*/
if (ovfl_ctrl.bits.mask_monitoring) {
pfm_mask_monitoring(task);
ctx->ctx_state = PFM_CTX_MASKED;
ctx->ctx_fl_can_restart = 1;
}
/*
* send notification now
*/
if (must_notify) pfm_ovfl_notify_user(ctx, ovfl_notify);
return;
sanity_check:
printk(KERN_ERR "perfmon: CPU%d overflow handler [%d] pmc0=0x%lx\n",
smp_processor_id(),
task ? task_pid_nr(task) : -1,
pmc0);
return;
stop_monitoring:
/*
* in SMP, zombie context is never restored but reclaimed in pfm_load_regs().
* Moreover, zombies are also reclaimed in pfm_save_regs(). Therefore we can
* come here as zombie only if the task is the current task. In which case, we
* can access the PMU hardware directly.
*
* Note that zombies do have PM_VALID set. So here we do the minimal.
*
* In case the context was zombified it could not be reclaimed at the time
* the monitoring program exited. At this point, the PMU reservation has been
* returned, the sampiing buffer has been freed. We must convert this call
* into a spurious interrupt. However, we must also avoid infinite overflows
* by stopping monitoring for this task. We can only come here for a per-task
* context. All we need to do is to stop monitoring using the psr bits which
* are always task private. By re-enabling secure montioring, we ensure that
* the monitored task will not be able to re-activate monitoring.
* The task will eventually be context switched out, at which point the context
* will be reclaimed (that includes releasing ownership of the PMU).
*
* So there might be a window of time where the number of per-task session is zero
* yet one PMU might have a owner and get at most one overflow interrupt for a zombie
* context. This is safe because if a per-task session comes in, it will push this one
* out and by the virtue on pfm_save_regs(), this one will disappear. If a system wide
* session is force on that CPU, given that we use task pinning, pfm_save_regs() will
* also push our zombie context out.
*
* Overall pretty hairy stuff....
*/
DPRINT(("ctx is zombie for [%d], converted to spurious\n", task ? task_pid_nr(task): -1));
pfm_clear_psr_up();
ia64_psr(regs)->up = 0;
ia64_psr(regs)->sp = 1;
return;
}
static int
pfm_do_interrupt_handler(void *arg, struct pt_regs *regs)
{
struct task_struct *task;
pfm_context_t *ctx;
unsigned long flags;
u64 pmc0;
int this_cpu = smp_processor_id();
int retval = 0;
pfm_stats[this_cpu].pfm_ovfl_intr_count++;
/*
* srlz.d done before arriving here
*/
pmc0 = ia64_get_pmc(0);
task = GET_PMU_OWNER();
ctx = GET_PMU_CTX();
/*
* if we have some pending bits set
* assumes : if any PMC0.bit[63-1] is set, then PMC0.fr = 1
*/
if (PMC0_HAS_OVFL(pmc0) && task) {
/*
* we assume that pmc0.fr is always set here
*/
/* sanity check */
if (!ctx) goto report_spurious1;
if (ctx->ctx_fl_system == 0 && (task->thread.flags & IA64_THREAD_PM_VALID) == 0)
goto report_spurious2;
PROTECT_CTX_NOPRINT(ctx, flags);
pfm_overflow_handler(task, ctx, pmc0, regs);
UNPROTECT_CTX_NOPRINT(ctx, flags);
} else {
pfm_stats[this_cpu].pfm_spurious_ovfl_intr_count++;
retval = -1;
}
/*
* keep it unfrozen at all times
*/
pfm_unfreeze_pmu();
return retval;
report_spurious1:
printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d has no PFM context\n",
this_cpu, task_pid_nr(task));
pfm_unfreeze_pmu();
return -1;
report_spurious2:
printk(KERN_INFO "perfmon: spurious overflow interrupt on CPU%d: process %d, invalid flag\n",
this_cpu,
task_pid_nr(task));
pfm_unfreeze_pmu();
return -1;
}
static irqreturn_t
pfm_interrupt_handler(int irq, void *arg)
{
unsigned long start_cycles, total_cycles;
unsigned long min, max;
int this_cpu;
int ret;
struct pt_regs *regs = get_irq_regs();
this_cpu = get_cpu();
if (likely(!pfm_alt_intr_handler)) {
min = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min;
max = pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max;
start_cycles = ia64_get_itc();
ret = pfm_do_interrupt_handler(arg, regs);
total_cycles = ia64_get_itc();
/*
* don't measure spurious interrupts
*/
if (likely(ret == 0)) {
total_cycles -= start_cycles;
if (total_cycles < min) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_min = total_cycles;
if (total_cycles > max) pfm_stats[this_cpu].pfm_ovfl_intr_cycles_max = total_cycles;
pfm_stats[this_cpu].pfm_ovfl_intr_cycles += total_cycles;
}
}
else {
(*pfm_alt_intr_handler->handler)(irq, arg, regs);
}
put_cpu_no_resched();
return IRQ_HANDLED;
}
/*
* /proc/perfmon interface, for debug only
*/
#define PFM_PROC_SHOW_HEADER ((void *)NR_CPUS+1)
static void *
pfm_proc_start(struct seq_file *m, loff_t *pos)
{
if (*pos == 0) {
return PFM_PROC_SHOW_HEADER;
}
while (*pos <= NR_CPUS) {
if (cpu_online(*pos - 1)) {
return (void *)*pos;
}
++*pos;
}
return NULL;
}
static void *
pfm_proc_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return pfm_proc_start(m, pos);
}
static void
pfm_proc_stop(struct seq_file *m, void *v)
{
}
static void
pfm_proc_show_header(struct seq_file *m)
{
struct list_head * pos;
pfm_buffer_fmt_t * entry;
unsigned long flags;
seq_printf(m,
"perfmon version : %u.%u\n"
"model : %s\n"
"fastctxsw : %s\n"
"expert mode : %s\n"
"ovfl_mask : 0x%lx\n"
"PMU flags : 0x%x\n",
PFM_VERSION_MAJ, PFM_VERSION_MIN,
pmu_conf->pmu_name,
pfm_sysctl.fastctxsw > 0 ? "Yes": "No",
pfm_sysctl.expert_mode > 0 ? "Yes": "No",
pmu_conf->ovfl_val,
pmu_conf->flags);
LOCK_PFS(flags);
seq_printf(m,
"proc_sessions : %u\n"
"sys_sessions : %u\n"
"sys_use_dbregs : %u\n"
"ptrace_use_dbregs : %u\n",
pfm_sessions.pfs_task_sessions,
pfm_sessions.pfs_sys_sessions,
pfm_sessions.pfs_sys_use_dbregs,
pfm_sessions.pfs_ptrace_use_dbregs);
UNLOCK_PFS(flags);
spin_lock(&pfm_buffer_fmt_lock);
list_for_each(pos, &pfm_buffer_fmt_list) {
entry = list_entry(pos, pfm_buffer_fmt_t, fmt_list);
seq_printf(m, "format : %02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x %s\n",
entry->fmt_uuid[0],
entry->fmt_uuid[1],
entry->fmt_uuid[2],
entry->fmt_uuid[3],
entry->fmt_uuid[4],
entry->fmt_uuid[5],
entry->fmt_uuid[6],
entry->fmt_uuid[7],
entry->fmt_uuid[8],
entry->fmt_uuid[9],
entry->fmt_uuid[10],
entry->fmt_uuid[11],
entry->fmt_uuid[12],
entry->fmt_uuid[13],
entry->fmt_uuid[14],
entry->fmt_uuid[15],
entry->fmt_name);
}
spin_unlock(&pfm_buffer_fmt_lock);
}
static int
pfm_proc_show(struct seq_file *m, void *v)
{
unsigned long psr;
unsigned int i;
int cpu;
if (v == PFM_PROC_SHOW_HEADER) {
pfm_proc_show_header(m);
return 0;
}
/* show info for CPU (v - 1) */
cpu = (long)v - 1;
seq_printf(m,
"CPU%-2d overflow intrs : %lu\n"
"CPU%-2d overflow cycles : %lu\n"
"CPU%-2d overflow min : %lu\n"
"CPU%-2d overflow max : %lu\n"
"CPU%-2d smpl handler calls : %lu\n"
"CPU%-2d smpl handler cycles : %lu\n"
"CPU%-2d spurious intrs : %lu\n"
"CPU%-2d replay intrs : %lu\n"
"CPU%-2d syst_wide : %d\n"
"CPU%-2d dcr_pp : %d\n"
"CPU%-2d exclude idle : %d\n"
"CPU%-2d owner : %d\n"
"CPU%-2d context : %p\n"
"CPU%-2d activations : %lu\n",
cpu, pfm_stats[cpu].pfm_ovfl_intr_count,
cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles,
cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_min,
cpu, pfm_stats[cpu].pfm_ovfl_intr_cycles_max,
cpu, pfm_stats[cpu].pfm_smpl_handler_calls,
cpu, pfm_stats[cpu].pfm_smpl_handler_cycles,
cpu, pfm_stats[cpu].pfm_spurious_ovfl_intr_count,
cpu, pfm_stats[cpu].pfm_replay_ovfl_intr_count,
cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_SYST_WIDE ? 1 : 0,
cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_DCR_PP ? 1 : 0,
cpu, pfm_get_cpu_data(pfm_syst_info, cpu) & PFM_CPUINFO_EXCL_IDLE ? 1 : 0,
cpu, pfm_get_cpu_data(pmu_owner, cpu) ? pfm_get_cpu_data(pmu_owner, cpu)->pid: -1,
cpu, pfm_get_cpu_data(pmu_ctx, cpu),
cpu, pfm_get_cpu_data(pmu_activation_number, cpu));
if (num_online_cpus() == 1 && pfm_sysctl.debug > 0) {
psr = pfm_get_psr();
ia64_srlz_d();
seq_printf(m,
"CPU%-2d psr : 0x%lx\n"
"CPU%-2d pmc0 : 0x%lx\n",
cpu, psr,
cpu, ia64_get_pmc(0));
for (i=0; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_COUNTING(i) == 0) continue;
seq_printf(m,
"CPU%-2d pmc%u : 0x%lx\n"
"CPU%-2d pmd%u : 0x%lx\n",
cpu, i, ia64_get_pmc(i),
cpu, i, ia64_get_pmd(i));
}
}
return 0;
}
const struct seq_operations pfm_seq_ops = {
.start = pfm_proc_start,
.next = pfm_proc_next,
.stop = pfm_proc_stop,
.show = pfm_proc_show
};
static int
pfm_proc_open(struct inode *inode, struct file *file)
{
return seq_open(file, &pfm_seq_ops);
}
/*
* we come here as soon as local_cpu_data->pfm_syst_wide is set. this happens
* during pfm_enable() hence before pfm_start(). We cannot assume monitoring
* is active or inactive based on mode. We must rely on the value in
* local_cpu_data->pfm_syst_info
*/
void
pfm_syst_wide_update_task(struct task_struct *task, unsigned long info, int is_ctxswin)
{
struct pt_regs *regs;
unsigned long dcr;
unsigned long dcr_pp;
dcr_pp = info & PFM_CPUINFO_DCR_PP ? 1 : 0;
/*
* pid 0 is guaranteed to be the idle task. There is one such task with pid 0
* on every CPU, so we can rely on the pid to identify the idle task.
*/
if ((info & PFM_CPUINFO_EXCL_IDLE) == 0 || task->pid) {
regs = task_pt_regs(task);
ia64_psr(regs)->pp = is_ctxswin ? dcr_pp : 0;
return;
}
/*
* if monitoring has started
*/
if (dcr_pp) {
dcr = ia64_getreg(_IA64_REG_CR_DCR);
/*
* context switching in?
*/
if (is_ctxswin) {
/* mask monitoring for the idle task */
ia64_setreg(_IA64_REG_CR_DCR, dcr & ~IA64_DCR_PP);
pfm_clear_psr_pp();
ia64_srlz_i();
return;
}
/*
* context switching out
* restore monitoring for next task
*
* Due to inlining this odd if-then-else construction generates
* better code.
*/
ia64_setreg(_IA64_REG_CR_DCR, dcr |IA64_DCR_PP);
pfm_set_psr_pp();
ia64_srlz_i();
}
}
#ifdef CONFIG_SMP
static void
pfm_force_cleanup(pfm_context_t *ctx, struct pt_regs *regs)
{
struct task_struct *task = ctx->ctx_task;
ia64_psr(regs)->up = 0;
ia64_psr(regs)->sp = 1;
if (GET_PMU_OWNER() == task) {
DPRINT(("cleared ownership for [%d]\n",
task_pid_nr(ctx->ctx_task)));
SET_PMU_OWNER(NULL, NULL);
}
/*
* disconnect the task from the context and vice-versa
*/
PFM_SET_WORK_PENDING(task, 0);
task->thread.pfm_context = NULL;
task->thread.flags &= ~IA64_THREAD_PM_VALID;
DPRINT(("force cleanup for [%d]\n", task_pid_nr(task)));
}
/*
* in 2.6, interrupts are masked when we come here and the runqueue lock is held
*/
void
pfm_save_regs(struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long flags;
u64 psr;
ctx = PFM_GET_CTX(task);
if (ctx == NULL) return;
/*
* we always come here with interrupts ALREADY disabled by
* the scheduler. So we simply need to protect against concurrent
* access, not CPU concurrency.
*/
flags = pfm_protect_ctx_ctxsw(ctx);
if (ctx->ctx_state == PFM_CTX_ZOMBIE) {
struct pt_regs *regs = task_pt_regs(task);
pfm_clear_psr_up();
pfm_force_cleanup(ctx, regs);
BUG_ON(ctx->ctx_smpl_hdr);
pfm_unprotect_ctx_ctxsw(ctx, flags);
pfm_context_free(ctx);
return;
}
/*
* save current PSR: needed because we modify it
*/
ia64_srlz_d();
psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_I));
/*
* stop monitoring:
* This is the last instruction which may generate an overflow
*
* We do not need to set psr.sp because, it is irrelevant in kernel.
* It will be restored from ipsr when going back to user level
*/
pfm_clear_psr_up();
/*
* keep a copy of psr.up (for reload)
*/
ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
/*
* release ownership of this PMU.
* PM interrupts are masked, so nothing
* can happen.
*/
SET_PMU_OWNER(NULL, NULL);
/*
* we systematically save the PMD as we have no
* guarantee we will be schedule at that same
* CPU again.
*/
pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
/*
* save pmc0 ia64_srlz_d() done in pfm_save_pmds()
* we will need it on the restore path to check
* for pending overflow.
*/
ctx->th_pmcs[0] = ia64_get_pmc(0);
/*
* unfreeze PMU if had pending overflows
*/
if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
/*
* finally, allow context access.
* interrupts will still be masked after this call.
*/
pfm_unprotect_ctx_ctxsw(ctx, flags);
}
#else /* !CONFIG_SMP */
void
pfm_save_regs(struct task_struct *task)
{
pfm_context_t *ctx;
u64 psr;
ctx = PFM_GET_CTX(task);
if (ctx == NULL) return;
/*
* save current PSR: needed because we modify it
*/
psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_I));
/*
* stop monitoring:
* This is the last instruction which may generate an overflow
*
* We do not need to set psr.sp because, it is irrelevant in kernel.
* It will be restored from ipsr when going back to user level
*/
pfm_clear_psr_up();
/*
* keep a copy of psr.up (for reload)
*/
ctx->ctx_saved_psr_up = psr & IA64_PSR_UP;
}
static void
pfm_lazy_save_regs (struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long flags;
{ u64 psr = pfm_get_psr();
BUG_ON(psr & IA64_PSR_UP);
}
ctx = PFM_GET_CTX(task);
/*
* we need to mask PMU overflow here to
* make sure that we maintain pmc0 until
* we save it. overflow interrupts are
* treated as spurious if there is no
* owner.
*
* XXX: I don't think this is necessary
*/
PROTECT_CTX(ctx,flags);
/*
* release ownership of this PMU.
* must be done before we save the registers.
*
* after this call any PMU interrupt is treated
* as spurious.
*/
SET_PMU_OWNER(NULL, NULL);
/*
* save all the pmds we use
*/
pfm_save_pmds(ctx->th_pmds, ctx->ctx_used_pmds[0]);
/*
* save pmc0 ia64_srlz_d() done in pfm_save_pmds()
* it is needed to check for pended overflow
* on the restore path
*/
ctx->th_pmcs[0] = ia64_get_pmc(0);
/*
* unfreeze PMU if had pending overflows
*/
if (ctx->th_pmcs[0] & ~0x1UL) pfm_unfreeze_pmu();
/*
* now get can unmask PMU interrupts, they will
* be treated as purely spurious and we will not
* lose any information
*/
UNPROTECT_CTX(ctx,flags);
}
#endif /* CONFIG_SMP */
#ifdef CONFIG_SMP
/*
* in 2.6, interrupts are masked when we come here and the runqueue lock is held
*/
void
pfm_load_regs (struct task_struct *task)
{
pfm_context_t *ctx;
unsigned long pmc_mask = 0UL, pmd_mask = 0UL;
unsigned long flags;
u64 psr, psr_up;
int need_irq_resend;
ctx = PFM_GET_CTX(task);
if (unlikely(ctx == NULL)) return;
BUG_ON(GET_PMU_OWNER());
/*
* possible on unload
*/
if (unlikely((task->thread.flags & IA64_THREAD_PM_VALID) == 0)) return;
/*
* we always come here with interrupts ALREADY disabled by
* the scheduler. So we simply need to protect against concurrent
* access, not CPU concurrency.
*/
flags = pfm_protect_ctx_ctxsw(ctx);
psr = pfm_get_psr();
need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
BUG_ON(psr & IA64_PSR_I);
if (unlikely(ctx->ctx_state == PFM_CTX_ZOMBIE)) {
struct pt_regs *regs = task_pt_regs(task);
BUG_ON(ctx->ctx_smpl_hdr);
pfm_force_cleanup(ctx, regs);
pfm_unprotect_ctx_ctxsw(ctx, flags);
/*
* this one (kmalloc'ed) is fine with interrupts disabled
*/
pfm_context_free(ctx);
return;
}
/*
* we restore ALL the debug registers to avoid picking up
* stale state.
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* retrieve saved psr.up
*/
psr_up = ctx->ctx_saved_psr_up;
/*
* if we were the last user of the PMU on that CPU,
* then nothing to do except restore psr
*/
if (GET_LAST_CPU(ctx) == smp_processor_id() && ctx->ctx_last_activation == GET_ACTIVATION()) {
/*
* retrieve partial reload masks (due to user modifications)
*/
pmc_mask = ctx->ctx_reload_pmcs[0];
pmd_mask = ctx->ctx_reload_pmds[0];
} else {
/*
* To avoid leaking information to the user level when psr.sp=0,
* we must reload ALL implemented pmds (even the ones we don't use).
* In the kernel we only allow PFM_READ_PMDS on registers which
* we initialized or requested (sampling) so there is no risk there.
*/
pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
/*
* ALL accessible PMCs are systematically reloaded, unused registers
* get their default (from pfm_reset_pmu_state()) values to avoid picking
* up stale configuration.
*
* PMC0 is never in the mask. It is always restored separately.
*/
pmc_mask = ctx->ctx_all_pmcs[0];
}
/*
* when context is MASKED, we will restore PMC with plm=0
* and PMD with stale information, but that's ok, nothing
* will be captured.
*
* XXX: optimize here
*/
if (pmd_mask) pfm_restore_pmds(ctx->th_pmds, pmd_mask);
if (pmc_mask) pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
/*
* check for pending overflow at the time the state
* was saved.
*/
if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
/*
* reload pmc0 with the overflow information
* On McKinley PMU, this will trigger a PMU interrupt
*/
ia64_set_pmc(0, ctx->th_pmcs[0]);
ia64_srlz_d();
ctx->th_pmcs[0] = 0UL;
/*
* will replay the PMU interrupt
*/
if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
}
/*
* we just did a reload, so we reset the partial reload fields
*/
ctx->ctx_reload_pmcs[0] = 0UL;
ctx->ctx_reload_pmds[0] = 0UL;
SET_LAST_CPU(ctx, smp_processor_id());
/*
* dump activation value for this PMU
*/
INC_ACTIVATION();
/*
* record current activation for this context
*/
SET_ACTIVATION(ctx);
/*
* establish new ownership.
*/
SET_PMU_OWNER(task, ctx);
/*
* restore the psr.up bit. measurement
* is active again.
* no PMU interrupt can happen at this point
* because we still have interrupts disabled.
*/
if (likely(psr_up)) pfm_set_psr_up();
/*
* allow concurrent access to context
*/
pfm_unprotect_ctx_ctxsw(ctx, flags);
}
#else /* !CONFIG_SMP */
/*
* reload PMU state for UP kernels
* in 2.5 we come here with interrupts disabled
*/
void
pfm_load_regs (struct task_struct *task)
{
pfm_context_t *ctx;
struct task_struct *owner;
unsigned long pmd_mask, pmc_mask;
u64 psr, psr_up;
int need_irq_resend;
owner = GET_PMU_OWNER();
ctx = PFM_GET_CTX(task);
psr = pfm_get_psr();
BUG_ON(psr & (IA64_PSR_UP|IA64_PSR_PP));
BUG_ON(psr & IA64_PSR_I);
/*
* we restore ALL the debug registers to avoid picking up
* stale state.
*
* This must be done even when the task is still the owner
* as the registers may have been modified via ptrace()
* (not perfmon) by the previous task.
*/
if (ctx->ctx_fl_using_dbreg) {
pfm_restore_ibrs(ctx->ctx_ibrs, pmu_conf->num_ibrs);
pfm_restore_dbrs(ctx->ctx_dbrs, pmu_conf->num_dbrs);
}
/*
* retrieved saved psr.up
*/
psr_up = ctx->ctx_saved_psr_up;
need_irq_resend = pmu_conf->flags & PFM_PMU_IRQ_RESEND;
/*
* short path, our state is still there, just
* need to restore psr and we go
*
* we do not touch either PMC nor PMD. the psr is not touched
* by the overflow_handler. So we are safe w.r.t. to interrupt
* concurrency even without interrupt masking.
*/
if (likely(owner == task)) {
if (likely(psr_up)) pfm_set_psr_up();
return;
}
/*
* someone else is still using the PMU, first push it out and
* then we'll be able to install our stuff !
*
* Upon return, there will be no owner for the current PMU
*/
if (owner) pfm_lazy_save_regs(owner);
/*
* To avoid leaking information to the user level when psr.sp=0,
* we must reload ALL implemented pmds (even the ones we don't use).
* In the kernel we only allow PFM_READ_PMDS on registers which
* we initialized or requested (sampling) so there is no risk there.
*/
pmd_mask = pfm_sysctl.fastctxsw ? ctx->ctx_used_pmds[0] : ctx->ctx_all_pmds[0];
/*
* ALL accessible PMCs are systematically reloaded, unused registers
* get their default (from pfm_reset_pmu_state()) values to avoid picking
* up stale configuration.
*
* PMC0 is never in the mask. It is always restored separately
*/
pmc_mask = ctx->ctx_all_pmcs[0];
pfm_restore_pmds(ctx->th_pmds, pmd_mask);
pfm_restore_pmcs(ctx->th_pmcs, pmc_mask);
/*
* check for pending overflow at the time the state
* was saved.
*/
if (unlikely(PMC0_HAS_OVFL(ctx->th_pmcs[0]))) {
/*
* reload pmc0 with the overflow information
* On McKinley PMU, this will trigger a PMU interrupt
*/
ia64_set_pmc(0, ctx->th_pmcs[0]);
ia64_srlz_d();
ctx->th_pmcs[0] = 0UL;
/*
* will replay the PMU interrupt
*/
if (need_irq_resend) ia64_resend_irq(IA64_PERFMON_VECTOR);
pfm_stats[smp_processor_id()].pfm_replay_ovfl_intr_count++;
}
/*
* establish new ownership.
*/
SET_PMU_OWNER(task, ctx);
/*
* restore the psr.up bit. measurement
* is active again.
* no PMU interrupt can happen at this point
* because we still have interrupts disabled.
*/
if (likely(psr_up)) pfm_set_psr_up();
}
#endif /* CONFIG_SMP */
/*
* this function assumes monitoring is stopped
*/
static void
pfm_flush_pmds(struct task_struct *task, pfm_context_t *ctx)
{
u64 pmc0;
unsigned long mask2, val, pmd_val, ovfl_val;
int i, can_access_pmu = 0;
int is_self;
/*
* is the caller the task being monitored (or which initiated the
* session for system wide measurements)
*/
is_self = ctx->ctx_task == task ? 1 : 0;
/*
* can access PMU is task is the owner of the PMU state on the current CPU
* or if we are running on the CPU bound to the context in system-wide mode
* (that is not necessarily the task the context is attached to in this mode).
* In system-wide we always have can_access_pmu true because a task running on an
* invalid processor is flagged earlier in the call stack (see pfm_stop).
*/
can_access_pmu = (GET_PMU_OWNER() == task) || (ctx->ctx_fl_system && ctx->ctx_cpu == smp_processor_id());
if (can_access_pmu) {
/*
* Mark the PMU as not owned
* This will cause the interrupt handler to do nothing in case an overflow
* interrupt was in-flight
* This also guarantees that pmc0 will contain the final state
* It virtually gives us full control on overflow processing from that point
* on.
*/
SET_PMU_OWNER(NULL, NULL);
DPRINT(("releasing ownership\n"));
/*
* read current overflow status:
*
* we are guaranteed to read the final stable state
*/
ia64_srlz_d();
pmc0 = ia64_get_pmc(0); /* slow */
/*
* reset freeze bit, overflow status information destroyed
*/
pfm_unfreeze_pmu();
} else {
pmc0 = ctx->th_pmcs[0];
/*
* clear whatever overflow status bits there were
*/
ctx->th_pmcs[0] = 0;
}
ovfl_val = pmu_conf->ovfl_val;
/*
* we save all the used pmds
* we take care of overflows for counting PMDs
*
* XXX: sampling situation is not taken into account here
*/
mask2 = ctx->ctx_used_pmds[0];
DPRINT(("is_self=%d ovfl_val=0x%lx mask2=0x%lx\n", is_self, ovfl_val, mask2));
for (i = 0; mask2; i++, mask2>>=1) {
/* skip non used pmds */
if ((mask2 & 0x1) == 0) continue;
/*
* can access PMU always true in system wide mode
*/
val = pmd_val = can_access_pmu ? ia64_get_pmd(i) : ctx->th_pmds[i];
if (PMD_IS_COUNTING(i)) {
DPRINT(("[%d] pmd[%d] ctx_pmd=0x%lx hw_pmd=0x%lx\n",
task_pid_nr(task),
i,
ctx->ctx_pmds[i].val,
val & ovfl_val));
/*
* we rebuild the full 64 bit value of the counter
*/
val = ctx->ctx_pmds[i].val + (val & ovfl_val);
/*
* now everything is in ctx_pmds[] and we need
* to clear the saved context from save_regs() such that
* pfm_read_pmds() gets the correct value
*/
pmd_val = 0UL;
/*
* take care of overflow inline
*/
if (pmc0 & (1UL << i)) {
val += 1 + ovfl_val;
DPRINT(("[%d] pmd[%d] overflowed\n", task_pid_nr(task), i));
}
}
DPRINT(("[%d] ctx_pmd[%d]=0x%lx pmd_val=0x%lx\n", task_pid_nr(task), i, val, pmd_val));
if (is_self) ctx->th_pmds[i] = pmd_val;
ctx->ctx_pmds[i].val = val;
}
}
static struct irqaction perfmon_irqaction = {
.handler = pfm_interrupt_handler,
.flags = IRQF_DISABLED,
.name = "perfmon"
};
static void
pfm_alt_save_pmu_state(void *data)
{
struct pt_regs *regs;
regs = task_pt_regs(current);
DPRINT(("called\n"));
/*
* should not be necessary but
* let's take not risk
*/
pfm_clear_psr_up();
pfm_clear_psr_pp();
ia64_psr(regs)->pp = 0;
/*
* This call is required
* May cause a spurious interrupt on some processors
*/
pfm_freeze_pmu();
ia64_srlz_d();
}
void
pfm_alt_restore_pmu_state(void *data)
{
struct pt_regs *regs;
regs = task_pt_regs(current);
DPRINT(("called\n"));
/*
* put PMU back in state expected
* by perfmon
*/
pfm_clear_psr_up();
pfm_clear_psr_pp();
ia64_psr(regs)->pp = 0;
/*
* perfmon runs with PMU unfrozen at all times
*/
pfm_unfreeze_pmu();
ia64_srlz_d();
}
int
pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
{
int ret, i;
int reserve_cpu;
/* some sanity checks */
if (hdl == NULL || hdl->handler == NULL) return -EINVAL;
/* do the easy test first */
if (pfm_alt_intr_handler) return -EBUSY;
/* one at a time in the install or remove, just fail the others */
if (!spin_trylock(&pfm_alt_install_check)) {
return -EBUSY;
}
/* reserve our session */
for_each_online_cpu(reserve_cpu) {
ret = pfm_reserve_session(NULL, 1, reserve_cpu);
if (ret) goto cleanup_reserve;
}
/* save the current system wide pmu states */
ret = on_each_cpu(pfm_alt_save_pmu_state, NULL, 0, 1);
if (ret) {
DPRINT(("on_each_cpu() failed: %d\n", ret));
goto cleanup_reserve;
}
/* officially change to the alternate interrupt handler */
pfm_alt_intr_handler = hdl;
spin_unlock(&pfm_alt_install_check);
return 0;
cleanup_reserve:
for_each_online_cpu(i) {
/* don't unreserve more than we reserved */
if (i >= reserve_cpu) break;
pfm_unreserve_session(NULL, 1, i);
}
spin_unlock(&pfm_alt_install_check);
return ret;
}
EXPORT_SYMBOL_GPL(pfm_install_alt_pmu_interrupt);
int
pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl)
{
int i;
int ret;
if (hdl == NULL) return -EINVAL;
/* cannot remove someone else's handler! */
if (pfm_alt_intr_handler != hdl) return -EINVAL;
/* one at a time in the install or remove, just fail the others */
if (!spin_trylock(&pfm_alt_install_check)) {
return -EBUSY;
}
pfm_alt_intr_handler = NULL;
ret = on_each_cpu(pfm_alt_restore_pmu_state, NULL, 0, 1);
if (ret) {
DPRINT(("on_each_cpu() failed: %d\n", ret));
}
for_each_online_cpu(i) {
pfm_unreserve_session(NULL, 1, i);
}
spin_unlock(&pfm_alt_install_check);
return 0;
}
EXPORT_SYMBOL_GPL(pfm_remove_alt_pmu_interrupt);
/*
* perfmon initialization routine, called from the initcall() table
*/
static int init_pfm_fs(void);
static int __init
pfm_probe_pmu(void)
{
pmu_config_t **p;
int family;
family = local_cpu_data->family;
p = pmu_confs;
while(*p) {
if ((*p)->probe) {
if ((*p)->probe() == 0) goto found;
} else if ((*p)->pmu_family == family || (*p)->pmu_family == 0xff) {
goto found;
}
p++;
}
return -1;
found:
pmu_conf = *p;
return 0;
}
static const struct file_operations pfm_proc_fops = {
.open = pfm_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
int __init
pfm_init(void)
{
unsigned int n, n_counters, i;
printk("perfmon: version %u.%u IRQ %u\n",
PFM_VERSION_MAJ,
PFM_VERSION_MIN,
IA64_PERFMON_VECTOR);
if (pfm_probe_pmu()) {
printk(KERN_INFO "perfmon: disabled, there is no support for processor family %d\n",
local_cpu_data->family);
return -ENODEV;
}
/*
* compute the number of implemented PMD/PMC from the
* description tables
*/
n = 0;
for (i=0; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_IMPL(i) == 0) continue;
pmu_conf->impl_pmcs[i>>6] |= 1UL << (i&63);
n++;
}
pmu_conf->num_pmcs = n;
n = 0; n_counters = 0;
for (i=0; PMD_IS_LAST(i) == 0; i++) {
if (PMD_IS_IMPL(i) == 0) continue;
pmu_conf->impl_pmds[i>>6] |= 1UL << (i&63);
n++;
if (PMD_IS_COUNTING(i)) n_counters++;
}
pmu_conf->num_pmds = n;
pmu_conf->num_counters = n_counters;
/*
* sanity checks on the number of debug registers
*/
if (pmu_conf->use_rr_dbregs) {
if (pmu_conf->num_ibrs > IA64_NUM_DBG_REGS) {
printk(KERN_INFO "perfmon: unsupported number of code debug registers (%u)\n", pmu_conf->num_ibrs);
pmu_conf = NULL;
return -1;
}
if (pmu_conf->num_dbrs > IA64_NUM_DBG_REGS) {
printk(KERN_INFO "perfmon: unsupported number of data debug registers (%u)\n", pmu_conf->num_ibrs);
pmu_conf = NULL;
return -1;
}
}
printk("perfmon: %s PMU detected, %u PMCs, %u PMDs, %u counters (%lu bits)\n",
pmu_conf->pmu_name,
pmu_conf->num_pmcs,
pmu_conf->num_pmds,
pmu_conf->num_counters,
ffz(pmu_conf->ovfl_val));
/* sanity check */
if (pmu_conf->num_pmds >= PFM_NUM_PMD_REGS || pmu_conf->num_pmcs >= PFM_NUM_PMC_REGS) {
printk(KERN_ERR "perfmon: not enough pmc/pmd, perfmon disabled\n");
pmu_conf = NULL;
return -1;
}
/*
* create /proc/perfmon (mostly for debugging purposes)
*/
perfmon_dir = proc_create("perfmon", S_IRUGO, NULL, &pfm_proc_fops);
if (perfmon_dir == NULL) {
printk(KERN_ERR "perfmon: cannot create /proc entry, perfmon disabled\n");
pmu_conf = NULL;
return -1;
}
/*
* create /proc/sys/kernel/perfmon (for debugging purposes)
*/
pfm_sysctl_header = register_sysctl_table(pfm_sysctl_root);
/*
* initialize all our spinlocks
*/
spin_lock_init(&pfm_sessions.pfs_lock);
spin_lock_init(&pfm_buffer_fmt_lock);
init_pfm_fs();
for(i=0; i < NR_CPUS; i++) pfm_stats[i].pfm_ovfl_intr_cycles_min = ~0UL;
return 0;
}
__initcall(pfm_init);
/*
* this function is called before pfm_init()
*/
void
pfm_init_percpu (void)
{
static int first_time=1;
/*
* make sure no measurement is active
* (may inherit programmed PMCs from EFI).
*/
pfm_clear_psr_pp();
pfm_clear_psr_up();
/*
* we run with the PMU not frozen at all times
*/
pfm_unfreeze_pmu();
if (first_time) {
register_percpu_irq(IA64_PERFMON_VECTOR, &perfmon_irqaction);
first_time=0;
}
ia64_setreg(_IA64_REG_CR_PMV, IA64_PERFMON_VECTOR);
ia64_srlz_d();
}
/*
* used for debug purposes only
*/
void
dump_pmu_state(const char *from)
{
struct task_struct *task;
struct pt_regs *regs;
pfm_context_t *ctx;
unsigned long psr, dcr, info, flags;
int i, this_cpu;
local_irq_save(flags);
this_cpu = smp_processor_id();
regs = task_pt_regs(current);
info = PFM_CPUINFO_GET();
dcr = ia64_getreg(_IA64_REG_CR_DCR);
if (info == 0 && ia64_psr(regs)->pp == 0 && (dcr & IA64_DCR_PP) == 0) {
local_irq_restore(flags);
return;
}
printk("CPU%d from %s() current [%d] iip=0x%lx %s\n",
this_cpu,
from,
task_pid_nr(current),
regs->cr_iip,
current->comm);
task = GET_PMU_OWNER();
ctx = GET_PMU_CTX();
printk("->CPU%d owner [%d] ctx=%p\n", this_cpu, task ? task_pid_nr(task) : -1, ctx);
psr = pfm_get_psr();
printk("->CPU%d pmc0=0x%lx psr.pp=%d psr.up=%d dcr.pp=%d syst_info=0x%lx user_psr.up=%d user_psr.pp=%d\n",
this_cpu,
ia64_get_pmc(0),
psr & IA64_PSR_PP ? 1 : 0,
psr & IA64_PSR_UP ? 1 : 0,
dcr & IA64_DCR_PP ? 1 : 0,
info,
ia64_psr(regs)->up,
ia64_psr(regs)->pp);
ia64_psr(regs)->up = 0;
ia64_psr(regs)->pp = 0;
for (i=1; PMC_IS_LAST(i) == 0; i++) {
if (PMC_IS_IMPL(i) == 0) continue;
printk("->CPU%d pmc[%d]=0x%lx thread_pmc[%d]=0x%lx\n", this_cpu, i, ia64_get_pmc(i), i, ctx->th_pmcs[i]);
}
for (i=1; PMD_IS_LAST(i) == 0; i++) {
if (PMD_IS_IMPL(i) == 0) continue;
printk("->CPU%d pmd[%d]=0x%lx thread_pmd[%d]=0x%lx\n", this_cpu, i, ia64_get_pmd(i), i, ctx->th_pmds[i]);
}
if (ctx) {
printk("->CPU%d ctx_state=%d vaddr=%p addr=%p fd=%d ctx_task=[%d] saved_psr_up=0x%lx\n",
this_cpu,
ctx->ctx_state,
ctx->ctx_smpl_vaddr,
ctx->ctx_smpl_hdr,
ctx->ctx_msgq_head,
ctx->ctx_msgq_tail,
ctx->ctx_saved_psr_up);
}
local_irq_restore(flags);
}
/*
* called from process.c:copy_thread(). task is new child.
*/
void
pfm_inherit(struct task_struct *task, struct pt_regs *regs)
{
struct thread_struct *thread;
DPRINT(("perfmon: pfm_inherit clearing state for [%d]\n", task_pid_nr(task)));
thread = &task->thread;
/*
* cut links inherited from parent (current)
*/
thread->pfm_context = NULL;
PFM_SET_WORK_PENDING(task, 0);
/*
* the psr bits are already set properly in copy_threads()
*/
}
#else /* !CONFIG_PERFMON */
asmlinkage long
sys_perfmonctl (int fd, int cmd, void *arg, int count)
{
return -ENOSYS;
}
#endif /* CONFIG_PERFMON */
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