android_kernel_xiaomi_sm8350/arch/ia64/kernel/smpboot.c
Nick Piggin 5bfb5d690f [PATCH] sched: disable preempt in idle tasks
Run idle threads with preempt disabled.

Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?

Might fix the CPU hotplugging hang which Nigel Cunningham noted.

We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.

After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep.  The CPU will continue executing
previous idle and have no chance to call play_dead.

By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.

From: alexs <ashepard@u.washington.edu>

  PPC build fix

From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>

  MIPS build fix

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:33 -08:00

885 lines
21 KiB
C

/*
* SMP boot-related support
*
* Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 2001, 2004-2005 Intel Corp
* Rohit Seth <rohit.seth@intel.com>
* Suresh Siddha <suresh.b.siddha@intel.com>
* Gordon Jin <gordon.jin@intel.com>
* Ashok Raj <ashok.raj@intel.com>
*
* 01/05/16 Rohit Seth <rohit.seth@intel.com> Moved SMP booting functions from smp.c to here.
* 01/04/27 David Mosberger <davidm@hpl.hp.com> Added ITC synching code.
* 02/07/31 David Mosberger <davidm@hpl.hp.com> Switch over to hotplug-CPU boot-sequence.
* smp_boot_cpus()/smp_commence() is replaced by
* smp_prepare_cpus()/__cpu_up()/smp_cpus_done().
* 04/06/21 Ashok Raj <ashok.raj@intel.com> Added CPU Hotplug Support
* 04/12/26 Jin Gordon <gordon.jin@intel.com>
* 04/12/26 Rohit Seth <rohit.seth@intel.com>
* Add multi-threading and multi-core detection
* 05/01/30 Suresh Siddha <suresh.b.siddha@intel.com>
* Setup cpu_sibling_map and cpu_core_map
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/bootmem.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/mm.h>
#include <linux/notifier.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/efi.h>
#include <linux/percpu.h>
#include <linux/bitops.h>
#include <asm/atomic.h>
#include <asm/cache.h>
#include <asm/current.h>
#include <asm/delay.h>
#include <asm/ia32.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/machvec.h>
#include <asm/mca.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/sal.h>
#include <asm/system.h>
#include <asm/tlbflush.h>
#include <asm/unistd.h>
#define SMP_DEBUG 0
#if SMP_DEBUG
#define Dprintk(x...) printk(x)
#else
#define Dprintk(x...)
#endif
#ifdef CONFIG_HOTPLUG_CPU
/*
* Store all idle threads, this can be reused instead of creating
* a new thread. Also avoids complicated thread destroy functionality
* for idle threads.
*/
struct task_struct *idle_thread_array[NR_CPUS];
/*
* Global array allocated for NR_CPUS at boot time
*/
struct sal_to_os_boot sal_boot_rendez_state[NR_CPUS];
/*
* start_ap in head.S uses this to store current booting cpu
* info.
*/
struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
#define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
#define get_idle_for_cpu(x) (idle_thread_array[(x)])
#define set_idle_for_cpu(x,p) (idle_thread_array[(x)] = (p))
#else
#define get_idle_for_cpu(x) (NULL)
#define set_idle_for_cpu(x,p)
#define set_brendez_area(x)
#endif
/*
* ITC synchronization related stuff:
*/
#define MASTER 0
#define SLAVE (SMP_CACHE_BYTES/8)
#define NUM_ROUNDS 64 /* magic value */
#define NUM_ITERS 5 /* likewise */
static DEFINE_SPINLOCK(itc_sync_lock);
static volatile unsigned long go[SLAVE + 1];
#define DEBUG_ITC_SYNC 0
extern void __devinit calibrate_delay (void);
extern void start_ap (void);
extern unsigned long ia64_iobase;
task_t *task_for_booting_cpu;
/*
* State for each CPU
*/
DEFINE_PER_CPU(int, cpu_state);
/* Bitmasks of currently online, and possible CPUs */
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
int smp_num_siblings = 1;
int smp_num_cpucores = 1;
/* which logical CPU number maps to which CPU (physical APIC ID) */
volatile int ia64_cpu_to_sapicid[NR_CPUS];
EXPORT_SYMBOL(ia64_cpu_to_sapicid);
static volatile cpumask_t cpu_callin_map;
struct smp_boot_data smp_boot_data __initdata;
unsigned long ap_wakeup_vector = -1; /* External Int use to wakeup APs */
char __initdata no_int_routing;
unsigned char smp_int_redirect; /* are INT and IPI redirectable by the chipset? */
static int __init
nointroute (char *str)
{
no_int_routing = 1;
printk ("no_int_routing on\n");
return 1;
}
__setup("nointroute", nointroute);
void
sync_master (void *arg)
{
unsigned long flags, i;
go[MASTER] = 0;
local_irq_save(flags);
{
for (i = 0; i < NUM_ROUNDS*NUM_ITERS; ++i) {
while (!go[MASTER])
cpu_relax();
go[MASTER] = 0;
go[SLAVE] = ia64_get_itc();
}
}
local_irq_restore(flags);
}
/*
* Return the number of cycles by which our itc differs from the itc on the master
* (time-keeper) CPU. A positive number indicates our itc is ahead of the master,
* negative that it is behind.
*/
static inline long
get_delta (long *rt, long *master)
{
unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
unsigned long tcenter, t0, t1, tm;
long i;
for (i = 0; i < NUM_ITERS; ++i) {
t0 = ia64_get_itc();
go[MASTER] = 1;
while (!(tm = go[SLAVE]))
cpu_relax();
go[SLAVE] = 0;
t1 = ia64_get_itc();
if (t1 - t0 < best_t1 - best_t0)
best_t0 = t0, best_t1 = t1, best_tm = tm;
}
*rt = best_t1 - best_t0;
*master = best_tm - best_t0;
/* average best_t0 and best_t1 without overflow: */
tcenter = (best_t0/2 + best_t1/2);
if (best_t0 % 2 + best_t1 % 2 == 2)
++tcenter;
return tcenter - best_tm;
}
/*
* Synchronize ar.itc of the current (slave) CPU with the ar.itc of the MASTER CPU
* (normally the time-keeper CPU). We use a closed loop to eliminate the possibility of
* unaccounted-for errors (such as getting a machine check in the middle of a calibration
* step). The basic idea is for the slave to ask the master what itc value it has and to
* read its own itc before and after the master responds. Each iteration gives us three
* timestamps:
*
* slave master
*
* t0 ---\
* ---\
* --->
* tm
* /---
* /---
* t1 <---
*
*
* The goal is to adjust the slave's ar.itc such that tm falls exactly half-way between t0
* and t1. If we achieve this, the clocks are synchronized provided the interconnect
* between the slave and the master is symmetric. Even if the interconnect were
* asymmetric, we would still know that the synchronization error is smaller than the
* roundtrip latency (t0 - t1).
*
* When the interconnect is quiet and symmetric, this lets us synchronize the itc to
* within one or two cycles. However, we can only *guarantee* that the synchronization is
* accurate to within a round-trip time, which is typically in the range of several
* hundred cycles (e.g., ~500 cycles). In practice, this means that the itc's are usually
* almost perfectly synchronized, but we shouldn't assume that the accuracy is much better
* than half a micro second or so.
*/
void
ia64_sync_itc (unsigned int master)
{
long i, delta, adj, adjust_latency = 0, done = 0;
unsigned long flags, rt, master_time_stamp, bound;
#if DEBUG_ITC_SYNC
struct {
long rt; /* roundtrip time */
long master; /* master's timestamp */
long diff; /* difference between midpoint and master's timestamp */
long lat; /* estimate of itc adjustment latency */
} t[NUM_ROUNDS];
#endif
/*
* Make sure local timer ticks are disabled while we sync. If
* they were enabled, we'd have to worry about nasty issues
* like setting the ITC ahead of (or a long time before) the
* next scheduled tick.
*/
BUG_ON((ia64_get_itv() & (1 << 16)) == 0);
go[MASTER] = 1;
if (smp_call_function_single(master, sync_master, NULL, 1, 0) < 0) {
printk(KERN_ERR "sync_itc: failed to get attention of CPU %u!\n", master);
return;
}
while (go[MASTER])
cpu_relax(); /* wait for master to be ready */
spin_lock_irqsave(&itc_sync_lock, flags);
{
for (i = 0; i < NUM_ROUNDS; ++i) {
delta = get_delta(&rt, &master_time_stamp);
if (delta == 0) {
done = 1; /* let's lock on to this... */
bound = rt;
}
if (!done) {
if (i > 0) {
adjust_latency += -delta;
adj = -delta + adjust_latency/4;
} else
adj = -delta;
ia64_set_itc(ia64_get_itc() + adj);
}
#if DEBUG_ITC_SYNC
t[i].rt = rt;
t[i].master = master_time_stamp;
t[i].diff = delta;
t[i].lat = adjust_latency/4;
#endif
}
}
spin_unlock_irqrestore(&itc_sync_lock, flags);
#if DEBUG_ITC_SYNC
for (i = 0; i < NUM_ROUNDS; ++i)
printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
t[i].rt, t[i].master, t[i].diff, t[i].lat);
#endif
printk(KERN_INFO "CPU %d: synchronized ITC with CPU %u (last diff %ld cycles, "
"maxerr %lu cycles)\n", smp_processor_id(), master, delta, rt);
}
/*
* Ideally sets up per-cpu profiling hooks. Doesn't do much now...
*/
static inline void __devinit
smp_setup_percpu_timer (void)
{
}
static void __devinit
smp_callin (void)
{
int cpuid, phys_id;
extern void ia64_init_itm(void);
#ifdef CONFIG_PERFMON
extern void pfm_init_percpu(void);
#endif
cpuid = smp_processor_id();
phys_id = hard_smp_processor_id();
if (cpu_online(cpuid)) {
printk(KERN_ERR "huh, phys CPU#0x%x, CPU#0x%x already present??\n",
phys_id, cpuid);
BUG();
}
lock_ipi_calllock();
cpu_set(cpuid, cpu_online_map);
unlock_ipi_calllock();
per_cpu(cpu_state, cpuid) = CPU_ONLINE;
smp_setup_percpu_timer();
ia64_mca_cmc_vector_setup(); /* Setup vector on AP */
#ifdef CONFIG_PERFMON
pfm_init_percpu();
#endif
local_irq_enable();
if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
/*
* Synchronize the ITC with the BP. Need to do this after irqs are
* enabled because ia64_sync_itc() calls smp_call_function_single(), which
* calls spin_unlock_bh(), which calls spin_unlock_bh(), which calls
* local_bh_enable(), which bugs out if irqs are not enabled...
*/
Dprintk("Going to syncup ITC with BP.\n");
ia64_sync_itc(0);
}
/*
* Get our bogomips.
*/
ia64_init_itm();
calibrate_delay();
local_cpu_data->loops_per_jiffy = loops_per_jiffy;
#ifdef CONFIG_IA32_SUPPORT
ia32_gdt_init();
#endif
/*
* Allow the master to continue.
*/
cpu_set(cpuid, cpu_callin_map);
Dprintk("Stack on CPU %d at about %p\n",cpuid, &cpuid);
}
/*
* Activate a secondary processor. head.S calls this.
*/
int __devinit
start_secondary (void *unused)
{
/* Early console may use I/O ports */
ia64_set_kr(IA64_KR_IO_BASE, __pa(ia64_iobase));
Dprintk("start_secondary: starting CPU 0x%x\n", hard_smp_processor_id());
efi_map_pal_code();
cpu_init();
preempt_disable();
smp_callin();
cpu_idle();
return 0;
}
struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
{
return NULL;
}
struct create_idle {
struct task_struct *idle;
struct completion done;
int cpu;
};
void
do_fork_idle(void *_c_idle)
{
struct create_idle *c_idle = _c_idle;
c_idle->idle = fork_idle(c_idle->cpu);
complete(&c_idle->done);
}
static int __devinit
do_boot_cpu (int sapicid, int cpu)
{
int timeout;
struct create_idle c_idle = {
.cpu = cpu,
.done = COMPLETION_INITIALIZER(c_idle.done),
};
DECLARE_WORK(work, do_fork_idle, &c_idle);
c_idle.idle = get_idle_for_cpu(cpu);
if (c_idle.idle) {
init_idle(c_idle.idle, cpu);
goto do_rest;
}
/*
* We can't use kernel_thread since we must avoid to reschedule the child.
*/
if (!keventd_up() || current_is_keventd())
work.func(work.data);
else {
schedule_work(&work);
wait_for_completion(&c_idle.done);
}
if (IS_ERR(c_idle.idle))
panic("failed fork for CPU %d", cpu);
set_idle_for_cpu(cpu, c_idle.idle);
do_rest:
task_for_booting_cpu = c_idle.idle;
Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
set_brendez_area(cpu);
platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
/*
* Wait 10s total for the AP to start
*/
Dprintk("Waiting on callin_map ...");
for (timeout = 0; timeout < 100000; timeout++) {
if (cpu_isset(cpu, cpu_callin_map))
break; /* It has booted */
udelay(100);
}
Dprintk("\n");
if (!cpu_isset(cpu, cpu_callin_map)) {
printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
ia64_cpu_to_sapicid[cpu] = -1;
cpu_clear(cpu, cpu_online_map); /* was set in smp_callin() */
return -EINVAL;
}
return 0;
}
static int __init
decay (char *str)
{
int ticks;
get_option (&str, &ticks);
return 1;
}
__setup("decay=", decay);
/*
* Initialize the logical CPU number to SAPICID mapping
*/
void __init
smp_build_cpu_map (void)
{
int sapicid, cpu, i;
int boot_cpu_id = hard_smp_processor_id();
for (cpu = 0; cpu < NR_CPUS; cpu++) {
ia64_cpu_to_sapicid[cpu] = -1;
#ifdef CONFIG_HOTPLUG_CPU
cpu_set(cpu, cpu_possible_map);
#endif
}
ia64_cpu_to_sapicid[0] = boot_cpu_id;
cpus_clear(cpu_present_map);
cpu_set(0, cpu_present_map);
cpu_set(0, cpu_possible_map);
for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
sapicid = smp_boot_data.cpu_phys_id[i];
if (sapicid == boot_cpu_id)
continue;
cpu_set(cpu, cpu_present_map);
cpu_set(cpu, cpu_possible_map);
ia64_cpu_to_sapicid[cpu] = sapicid;
cpu++;
}
}
/*
* Cycle through the APs sending Wakeup IPIs to boot each.
*/
void __init
smp_prepare_cpus (unsigned int max_cpus)
{
int boot_cpu_id = hard_smp_processor_id();
/*
* Initialize the per-CPU profiling counter/multiplier
*/
smp_setup_percpu_timer();
/*
* We have the boot CPU online for sure.
*/
cpu_set(0, cpu_online_map);
cpu_set(0, cpu_callin_map);
local_cpu_data->loops_per_jiffy = loops_per_jiffy;
ia64_cpu_to_sapicid[0] = boot_cpu_id;
printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);
current_thread_info()->cpu = 0;
/*
* If SMP should be disabled, then really disable it!
*/
if (!max_cpus) {
printk(KERN_INFO "SMP mode deactivated.\n");
cpus_clear(cpu_online_map);
cpus_clear(cpu_present_map);
cpus_clear(cpu_possible_map);
cpu_set(0, cpu_online_map);
cpu_set(0, cpu_present_map);
cpu_set(0, cpu_possible_map);
return;
}
}
void __devinit smp_prepare_boot_cpu(void)
{
cpu_set(smp_processor_id(), cpu_online_map);
cpu_set(smp_processor_id(), cpu_callin_map);
per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
}
/*
* mt_info[] is a temporary store for all info returned by
* PAL_LOGICAL_TO_PHYSICAL, to be copied into cpuinfo_ia64 when the
* specific cpu comes.
*/
static struct {
__u32 socket_id;
__u16 core_id;
__u16 thread_id;
__u16 proc_fixed_addr;
__u8 valid;
} mt_info[NR_CPUS] __devinitdata;
#ifdef CONFIG_HOTPLUG_CPU
static inline void
remove_from_mtinfo(int cpu)
{
int i;
for_each_cpu(i)
if (mt_info[i].valid && mt_info[i].socket_id ==
cpu_data(cpu)->socket_id)
mt_info[i].valid = 0;
}
static inline void
clear_cpu_sibling_map(int cpu)
{
int i;
for_each_cpu_mask(i, cpu_sibling_map[cpu])
cpu_clear(cpu, cpu_sibling_map[i]);
for_each_cpu_mask(i, cpu_core_map[cpu])
cpu_clear(cpu, cpu_core_map[i]);
cpu_sibling_map[cpu] = cpu_core_map[cpu] = CPU_MASK_NONE;
}
static void
remove_siblinginfo(int cpu)
{
int last = 0;
if (cpu_data(cpu)->threads_per_core == 1 &&
cpu_data(cpu)->cores_per_socket == 1) {
cpu_clear(cpu, cpu_core_map[cpu]);
cpu_clear(cpu, cpu_sibling_map[cpu]);
return;
}
last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);
/* remove it from all sibling map's */
clear_cpu_sibling_map(cpu);
/* if this cpu is the last in the core group, remove all its info
* from mt_info structure
*/
if (last)
remove_from_mtinfo(cpu);
}
extern void fixup_irqs(void);
/* must be called with cpucontrol mutex held */
int __cpu_disable(void)
{
int cpu = smp_processor_id();
/*
* dont permit boot processor for now
*/
if (cpu == 0)
return -EBUSY;
remove_siblinginfo(cpu);
cpu_clear(cpu, cpu_online_map);
fixup_irqs();
local_flush_tlb_all();
cpu_clear(cpu, cpu_callin_map);
return 0;
}
void __cpu_die(unsigned int cpu)
{
unsigned int i;
for (i = 0; i < 100; i++) {
/* They ack this in play_dead by setting CPU_DEAD */
if (per_cpu(cpu_state, cpu) == CPU_DEAD)
{
printk ("CPU %d is now offline\n", cpu);
return;
}
msleep(100);
}
printk(KERN_ERR "CPU %u didn't die...\n", cpu);
}
#else /* !CONFIG_HOTPLUG_CPU */
int __cpu_disable(void)
{
return -ENOSYS;
}
void __cpu_die(unsigned int cpu)
{
/* We said "no" in __cpu_disable */
BUG();
}
#endif /* CONFIG_HOTPLUG_CPU */
void
smp_cpus_done (unsigned int dummy)
{
int cpu;
unsigned long bogosum = 0;
/*
* Allow the user to impress friends.
*/
for_each_online_cpu(cpu) {
bogosum += cpu_data(cpu)->loops_per_jiffy;
}
printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
(int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
}
static inline void __devinit
set_cpu_sibling_map(int cpu)
{
int i;
for_each_online_cpu(i) {
if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
cpu_set(i, cpu_core_map[cpu]);
cpu_set(cpu, cpu_core_map[i]);
if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
cpu_set(i, cpu_sibling_map[cpu]);
cpu_set(cpu, cpu_sibling_map[i]);
}
}
}
}
int __devinit
__cpu_up (unsigned int cpu)
{
int ret;
int sapicid;
sapicid = ia64_cpu_to_sapicid[cpu];
if (sapicid == -1)
return -EINVAL;
/*
* Already booted cpu? not valid anymore since we dont
* do idle loop tightspin anymore.
*/
if (cpu_isset(cpu, cpu_callin_map))
return -EINVAL;
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
/* Processor goes to start_secondary(), sets online flag */
ret = do_boot_cpu(sapicid, cpu);
if (ret < 0)
return ret;
if (cpu_data(cpu)->threads_per_core == 1 &&
cpu_data(cpu)->cores_per_socket == 1) {
cpu_set(cpu, cpu_sibling_map[cpu]);
cpu_set(cpu, cpu_core_map[cpu]);
return 0;
}
set_cpu_sibling_map(cpu);
return 0;
}
/*
* Assume that CPU's have been discovered by some platform-dependent interface. For
* SoftSDV/Lion, that would be ACPI.
*
* Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
*/
void __init
init_smp_config(void)
{
struct fptr {
unsigned long fp;
unsigned long gp;
} *ap_startup;
long sal_ret;
/* Tell SAL where to drop the AP's. */
ap_startup = (struct fptr *) start_ap;
sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
if (sal_ret < 0)
printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
ia64_sal_strerror(sal_ret));
}
static inline int __devinit
check_for_mtinfo_index(void)
{
int i;
for_each_cpu(i)
if (!mt_info[i].valid)
return i;
return -1;
}
/*
* Search the mt_info to find out if this socket's cid/tid information is
* cached or not. If the socket exists, fill in the core_id and thread_id
* in cpuinfo
*/
static int __devinit
check_for_new_socket(__u16 logical_address, struct cpuinfo_ia64 *c)
{
int i;
__u32 sid = c->socket_id;
for_each_cpu(i) {
if (mt_info[i].valid && mt_info[i].proc_fixed_addr == logical_address
&& mt_info[i].socket_id == sid) {
c->core_id = mt_info[i].core_id;
c->thread_id = mt_info[i].thread_id;
return 1; /* not a new socket */
}
}
return 0;
}
/*
* identify_siblings(cpu) gets called from identify_cpu. This populates the
* information related to logical execution units in per_cpu_data structure.
*/
void __devinit
identify_siblings(struct cpuinfo_ia64 *c)
{
s64 status;
u16 pltid;
u64 proc_fixed_addr;
int count, i;
pal_logical_to_physical_t info;
if (smp_num_cpucores == 1 && smp_num_siblings == 1)
return;
if ((status = ia64_pal_logical_to_phys(0, &info)) != PAL_STATUS_SUCCESS) {
printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
status);
return;
}
if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
return;
}
if ((status = ia64_pal_fixed_addr(&proc_fixed_addr)) != PAL_STATUS_SUCCESS) {
printk(KERN_ERR "ia64_pal_fixed_addr failed with %ld\n", status);
return;
}
c->socket_id = (pltid << 8) | info.overview_ppid;
c->cores_per_socket = info.overview_cpp;
c->threads_per_core = info.overview_tpc;
count = c->num_log = info.overview_num_log;
/* If the thread and core id information is already cached, then
* we will simply update cpu_info and return. Otherwise, we will
* do the PAL calls and cache core and thread id's of all the siblings.
*/
if (check_for_new_socket(proc_fixed_addr, c))
return;
for (i = 0; i < count; i++) {
int index;
if (i && (status = ia64_pal_logical_to_phys(i, &info))
!= PAL_STATUS_SUCCESS) {
printk(KERN_ERR "ia64_pal_logical_to_phys failed"
" with %ld\n", status);
return;
}
if (info.log2_la == proc_fixed_addr) {
c->core_id = info.log1_cid;
c->thread_id = info.log1_tid;
}
index = check_for_mtinfo_index();
/* We will not do the mt_info caching optimization in this case.
*/
if (index < 0)
continue;
mt_info[index].valid = 1;
mt_info[index].socket_id = c->socket_id;
mt_info[index].core_id = info.log1_cid;
mt_info[index].thread_id = info.log1_tid;
mt_info[index].proc_fixed_addr = info.log2_la;
}
}