android_kernel_xiaomi_sm8350/arch/parisc/kernel/smp.c
James Bottomley 7085689ed1 [PARISC] Allow nested interrupts
Our prior mode of operation didn't allow nested interrupts
because it makes the interrupt code much simpler.  However,
nested interrupts are better for latency.

This code uses the EIEM register to simulate level interrupts
and thus achieve nesting.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-10-04 06:48:57 -06:00

734 lines
16 KiB
C

/*
** SMP Support
**
** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
**
** Lots of stuff stolen from arch/alpha/kernel/smp.c
** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
**
** Thanks to John Curry and Ullas Ponnadi. I learned alot from their work.
** -grant (1/12/2001)
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
*/
#undef ENTRY_SYS_CPUS /* syscall support for iCOD-like functionality */
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
#include <linux/kernel_stat.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <asm/system.h>
#include <asm/atomic.h>
#include <asm/current.h>
#include <asm/delay.h>
#include <asm/tlbflush.h>
#include <asm/io.h>
#include <asm/irq.h> /* for CPU_IRQ_REGION and friends */
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#define kDEBUG 0
DEFINE_SPINLOCK(smp_lock);
volatile struct task_struct *smp_init_current_idle_task;
static volatile int cpu_now_booting __read_mostly = 0; /* track which CPU is booting */
static int parisc_max_cpus __read_mostly = 1;
/* online cpus are ones that we've managed to bring up completely
* possible cpus are all valid cpu
* present cpus are all detected cpu
*
* On startup we bring up the "possible" cpus. Since we discover
* CPUs later, we add them as hotplug, so the possible cpu mask is
* empty in the beginning.
*/
cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE; /* Bitmap of online CPUs */
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; /* Bitmap of Present CPUs */
EXPORT_SYMBOL(cpu_online_map);
EXPORT_SYMBOL(cpu_possible_map);
struct smp_call_struct {
void (*func) (void *info);
void *info;
long wait;
atomic_t unstarted_count;
atomic_t unfinished_count;
};
static volatile struct smp_call_struct *smp_call_function_data;
enum ipi_message_type {
IPI_NOP=0,
IPI_RESCHEDULE=1,
IPI_CALL_FUNC,
IPI_CPU_START,
IPI_CPU_STOP,
IPI_CPU_TEST
};
/********** SMP inter processor interrupt and communication routines */
#undef PER_CPU_IRQ_REGION
#ifdef PER_CPU_IRQ_REGION
/* XXX REVISIT Ignore for now.
** *May* need this "hook" to register IPI handler
** once we have perCPU ExtIntr switch tables.
*/
static void
ipi_init(int cpuid)
{
/* If CPU is present ... */
#ifdef ENTRY_SYS_CPUS
/* *and* running (not stopped) ... */
#error iCOD support wants state checked here.
#endif
#error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
if(cpu_online(cpuid) )
{
switch_to_idle_task(current);
}
return;
}
#endif
/*
** Yoink this CPU from the runnable list...
**
*/
static void
halt_processor(void)
{
#ifdef ENTRY_SYS_CPUS
#error halt_processor() needs rework
/*
** o migrate I/O interrupts off this CPU.
** o leave IPI enabled - __cli() will disable IPI.
** o leave CPU in online map - just change the state
*/
cpu_data[this_cpu].state = STATE_STOPPED;
mark_bh(IPI_BH);
#else
/* REVISIT : redirect I/O Interrupts to another CPU? */
/* REVISIT : does PM *know* this CPU isn't available? */
cpu_clear(smp_processor_id(), cpu_online_map);
local_irq_disable();
for (;;)
;
#endif
}
irqreturn_t
ipi_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
int this_cpu = smp_processor_id();
struct cpuinfo_parisc *p = &cpu_data[this_cpu];
unsigned long ops;
unsigned long flags;
/* Count this now; we may make a call that never returns. */
p->ipi_count++;
mb(); /* Order interrupt and bit testing. */
for (;;) {
spin_lock_irqsave(&(p->lock),flags);
ops = p->pending_ipi;
p->pending_ipi = 0;
spin_unlock_irqrestore(&(p->lock),flags);
mb(); /* Order bit clearing and data access. */
if (!ops)
break;
while (ops) {
unsigned long which = ffz(~ops);
ops &= ~(1 << which);
switch (which) {
case IPI_NOP:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_NOP\n",this_cpu);
#endif /* kDEBUG */
break;
case IPI_RESCHEDULE:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_RESCHEDULE\n",this_cpu);
#endif /* kDEBUG */
/*
* Reschedule callback. Everything to be
* done is done by the interrupt return path.
*/
break;
case IPI_CALL_FUNC:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_CALL_FUNC\n",this_cpu);
#endif /* kDEBUG */
{
volatile struct smp_call_struct *data;
void (*func)(void *info);
void *info;
int wait;
data = smp_call_function_data;
func = data->func;
info = data->info;
wait = data->wait;
mb();
atomic_dec ((atomic_t *)&data->unstarted_count);
/* At this point, *data can't
* be relied upon.
*/
(*func)(info);
/* Notify the sending CPU that the
* task is done.
*/
mb();
if (wait)
atomic_dec ((atomic_t *)&data->unfinished_count);
}
break;
case IPI_CPU_START:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_CPU_START\n",this_cpu);
#endif /* kDEBUG */
#ifdef ENTRY_SYS_CPUS
p->state = STATE_RUNNING;
#endif
break;
case IPI_CPU_STOP:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d IPI_CPU_STOP\n",this_cpu);
#endif /* kDEBUG */
#ifdef ENTRY_SYS_CPUS
#else
halt_processor();
#endif
break;
case IPI_CPU_TEST:
#if (kDEBUG>=100)
printk(KERN_DEBUG "CPU%d is alive!\n",this_cpu);
#endif /* kDEBUG */
break;
default:
printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
this_cpu, which);
return IRQ_NONE;
} /* Switch */
/* let in any pending interrupts */
local_irq_enable();
local_irq_disable();
} /* while (ops) */
}
return IRQ_HANDLED;
}
static inline void
ipi_send(int cpu, enum ipi_message_type op)
{
struct cpuinfo_parisc *p = &cpu_data[cpu];
unsigned long flags;
spin_lock_irqsave(&(p->lock),flags);
p->pending_ipi |= 1 << op;
gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa);
spin_unlock_irqrestore(&(p->lock),flags);
}
static inline void
send_IPI_single(int dest_cpu, enum ipi_message_type op)
{
if (dest_cpu == NO_PROC_ID) {
BUG();
return;
}
ipi_send(dest_cpu, op);
}
static inline void
send_IPI_allbutself(enum ipi_message_type op)
{
int i;
for_each_online_cpu(i) {
if (i != smp_processor_id())
send_IPI_single(i, op);
}
}
inline void
smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }
static inline void
smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); }
void
smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
void
smp_send_all_nop(void)
{
send_IPI_allbutself(IPI_NOP);
}
/**
* Run a function on all other CPUs.
* <func> The function to run. This must be fast and non-blocking.
* <info> An arbitrary pointer to pass to the function.
* <retry> If true, keep retrying until ready.
* <wait> If true, wait until function has completed on other CPUs.
* [RETURNS] 0 on success, else a negative status code.
*
* Does not return until remote CPUs are nearly ready to execute <func>
* or have executed.
*/
int
smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
{
struct smp_call_struct data;
unsigned long timeout;
static DEFINE_SPINLOCK(lock);
int retries = 0;
if (num_online_cpus() < 2)
return 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
/* can also deadlock if IPIs are disabled */
WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0);
data.func = func;
data.info = info;
data.wait = wait;
atomic_set(&data.unstarted_count, num_online_cpus() - 1);
atomic_set(&data.unfinished_count, num_online_cpus() - 1);
if (retry) {
spin_lock (&lock);
while (smp_call_function_data != 0)
barrier();
}
else {
spin_lock (&lock);
if (smp_call_function_data) {
spin_unlock (&lock);
return -EBUSY;
}
}
smp_call_function_data = &data;
spin_unlock (&lock);
/* Send a message to all other CPUs and wait for them to respond */
send_IPI_allbutself(IPI_CALL_FUNC);
retry:
/* Wait for response */
timeout = jiffies + HZ;
while ( (atomic_read (&data.unstarted_count) > 0) &&
time_before (jiffies, timeout) )
barrier ();
if (atomic_read (&data.unstarted_count) > 0) {
printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
smp_processor_id(), ++retries);
goto retry;
}
/* We either got one or timed out. Release the lock */
mb();
smp_call_function_data = NULL;
while (wait && atomic_read (&data.unfinished_count) > 0)
barrier ();
return 0;
}
EXPORT_SYMBOL(smp_call_function);
/*
* Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
* as we want to ensure all TLB's flushed before proceeding.
*/
void
smp_flush_tlb_all(void)
{
on_each_cpu(flush_tlb_all_local, NULL, 1, 1);
}
void
smp_do_timer(struct pt_regs *regs)
{
int cpu = smp_processor_id();
struct cpuinfo_parisc *data = &cpu_data[cpu];
if (!--data->prof_counter) {
data->prof_counter = data->prof_multiplier;
update_process_times(user_mode(regs));
}
}
/*
* Called by secondaries to update state and initialize CPU registers.
*/
static void __init
smp_cpu_init(int cpunum)
{
extern int init_per_cpu(int); /* arch/parisc/kernel/processor.c */
extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */
extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
/* Set modes and Enable floating point coprocessor */
(void) init_per_cpu(cpunum);
disable_sr_hashing();
mb();
/* Well, support 2.4 linux scheme as well. */
if (cpu_test_and_set(cpunum, cpu_online_map))
{
extern void machine_halt(void); /* arch/parisc.../process.c */
printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
machine_halt();
}
/* Initialise the idle task for this CPU */
atomic_inc(&init_mm.mm_count);
current->active_mm = &init_mm;
if(current->mm)
BUG();
enter_lazy_tlb(&init_mm, current);
init_IRQ(); /* make sure no IRQ's are enabled or pending */
start_cpu_itimer();
}
/*
* Slaves start using C here. Indirectly called from smp_slave_stext.
* Do what start_kernel() and main() do for boot strap processor (aka monarch)
*/
void __init smp_callin(void)
{
int slave_id = cpu_now_booting;
#if 0
void *istack;
#endif
smp_cpu_init(slave_id);
preempt_disable();
#if 0 /* NOT WORKING YET - see entry.S */
istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER);
if (istack == NULL) {
printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id);
BUG();
}
mtctl(istack,31);
#endif
flush_cache_all_local(); /* start with known state */
flush_tlb_all_local(NULL);
local_irq_enable(); /* Interrupts have been off until now */
cpu_idle(); /* Wait for timer to schedule some work */
/* NOTREACHED */
panic("smp_callin() AAAAaaaaahhhh....\n");
}
/*
* Bring one cpu online.
*/
int __init smp_boot_one_cpu(int cpuid)
{
struct task_struct *idle;
long timeout;
/*
* Create an idle task for this CPU. Note the address wed* give
* to kernel_thread is irrelevant -- it's going to start
* where OS_BOOT_RENDEVZ vector in SAL says to start. But
* this gets all the other task-y sort of data structures set
* up like we wish. We need to pull the just created idle task
* off the run queue and stuff it into the init_tasks[] array.
* Sheesh . . .
*/
idle = fork_idle(cpuid);
if (IS_ERR(idle))
panic("SMP: fork failed for CPU:%d", cpuid);
task_thread_info(idle)->cpu = cpuid;
/* Let _start know what logical CPU we're booting
** (offset into init_tasks[],cpu_data[])
*/
cpu_now_booting = cpuid;
/*
** boot strap code needs to know the task address since
** it also contains the process stack.
*/
smp_init_current_idle_task = idle ;
mb();
printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa);
/*
** This gets PDC to release the CPU from a very tight loop.
**
** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
** is executed after receiving the rendezvous signal (an interrupt to
** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
** contents of memory are valid."
*/
gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, cpu_data[cpuid].hpa);
mb();
/*
* OK, wait a bit for that CPU to finish staggering about.
* Slave will set a bit when it reaches smp_cpu_init().
* Once the "monarch CPU" sees the bit change, it can move on.
*/
for (timeout = 0; timeout < 10000; timeout++) {
if(cpu_online(cpuid)) {
/* Which implies Slave has started up */
cpu_now_booting = 0;
smp_init_current_idle_task = NULL;
goto alive ;
}
udelay(100);
barrier();
}
put_task_struct(idle);
idle = NULL;
printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
return -1;
alive:
/* Remember the Slave data */
#if (kDEBUG>=100)
printk(KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
cpuid, timeout * 100);
#endif /* kDEBUG */
#ifdef ENTRY_SYS_CPUS
cpu_data[cpuid].state = STATE_RUNNING;
#endif
return 0;
}
void __devinit smp_prepare_boot_cpu(void)
{
int bootstrap_processor=cpu_data[0].cpuid; /* CPU ID of BSP */
#ifdef ENTRY_SYS_CPUS
cpu_data[0].state = STATE_RUNNING;
#endif
/* Setup BSP mappings */
printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor);
cpu_set(bootstrap_processor, cpu_online_map);
cpu_set(bootstrap_processor, cpu_present_map);
}
/*
** inventory.c:do_inventory() hasn't yet been run and thus we
** don't 'discover' the additional CPU's until later.
*/
void __init smp_prepare_cpus(unsigned int max_cpus)
{
cpus_clear(cpu_present_map);
cpu_set(0, cpu_present_map);
parisc_max_cpus = max_cpus;
if (!max_cpus)
printk(KERN_INFO "SMP mode deactivated.\n");
}
void smp_cpus_done(unsigned int cpu_max)
{
return;
}
int __devinit __cpu_up(unsigned int cpu)
{
if (cpu != 0 && cpu < parisc_max_cpus)
smp_boot_one_cpu(cpu);
return cpu_online(cpu) ? 0 : -ENOSYS;
}
#ifdef ENTRY_SYS_CPUS
/* Code goes along with:
** entry.s: ENTRY_NAME(sys_cpus) / * 215, for cpu stat * /
*/
int sys_cpus(int argc, char **argv)
{
int i,j=0;
extern int current_pid(int cpu);
if( argc > 2 ) {
printk("sys_cpus:Only one argument supported\n");
return (-1);
}
if ( argc == 1 ){
#ifdef DUMP_MORE_STATE
for_each_online_cpu(i) {
int cpus_per_line = 4;
if (j++ % cpus_per_line)
printk(" %3d",i);
else
printk("\n %3d",i);
}
printk("\n");
#else
printk("\n 0\n");
#endif
} else if((argc==2) && !(strcmp(argv[1],"-l"))) {
printk("\nCPUSTATE TASK CPUNUM CPUID HARDCPU(HPA)\n");
#ifdef DUMP_MORE_STATE
for_each_online_cpu(i) {
if (cpu_data[i].cpuid != NO_PROC_ID) {
switch(cpu_data[i].state) {
case STATE_RENDEZVOUS:
printk("RENDEZVS ");
break;
case STATE_RUNNING:
printk((current_pid(i)!=0) ? "RUNNING " : "IDLING ");
break;
case STATE_STOPPED:
printk("STOPPED ");
break;
case STATE_HALTED:
printk("HALTED ");
break;
default:
printk("%08x?", cpu_data[i].state);
break;
}
if(cpu_online(i)) {
printk(" %4d",current_pid(i));
}
printk(" %6d",cpu_number_map(i));
printk(" %5d",i);
printk(" 0x%lx\n",cpu_data[i].hpa);
}
}
#else
printk("\n%s %4d 0 0 --------",
(current->pid)?"RUNNING ": "IDLING ",current->pid);
#endif
} else if ((argc==2) && !(strcmp(argv[1],"-s"))) {
#ifdef DUMP_MORE_STATE
printk("\nCPUSTATE CPUID\n");
for_each_online_cpu(i) {
if (cpu_data[i].cpuid != NO_PROC_ID) {
switch(cpu_data[i].state) {
case STATE_RENDEZVOUS:
printk("RENDEZVS");break;
case STATE_RUNNING:
printk((current_pid(i)!=0) ? "RUNNING " : "IDLING");
break;
case STATE_STOPPED:
printk("STOPPED ");break;
case STATE_HALTED:
printk("HALTED ");break;
default:
}
printk(" %5d\n",i);
}
}
#else
printk("\n%s CPU0",(current->pid==0)?"RUNNING ":"IDLING ");
#endif
} else {
printk("sys_cpus:Unknown request\n");
return (-1);
}
return 0;
}
#endif /* ENTRY_SYS_CPUS */
#ifdef CONFIG_PROC_FS
int __init
setup_profiling_timer(unsigned int multiplier)
{
return -EINVAL;
}
#endif