linux/arch/arm/kernel/smp.c

705 lines
15 KiB
C

/*
* linux/arch/arm/kernel/smp.c
*
* Copyright (C) 2002 ARM Limited, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/cache.h>
#include <linux/profile.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/seq_file.h>
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/processor.h>
#include <asm/tlbflush.h>
#include <asm/ptrace.h>
#include <asm/localtimer.h>
#include <asm/smp_plat.h>
/*
* as from 2.5, kernels no longer have an init_tasks structure
* so we need some other way of telling a new secondary core
* where to place its SVC stack
*/
struct secondary_data secondary_data;
/*
* structures for inter-processor calls
* - A collection of single bit ipi messages.
*/
struct ipi_data {
spinlock_t lock;
unsigned long ipi_count;
unsigned long bits;
};
static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
.lock = SPIN_LOCK_UNLOCKED,
};
enum ipi_msg_type {
IPI_TIMER,
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CALL_FUNC_SINGLE,
IPI_CPU_STOP,
};
int __cpuinit __cpu_up(unsigned int cpu)
{
struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
struct task_struct *idle = ci->idle;
pgd_t *pgd;
pmd_t *pmd;
int ret;
/*
* Spawn a new process manually, if not already done.
* Grab a pointer to its task struct so we can mess with it
*/
if (!idle) {
idle = fork_idle(cpu);
if (IS_ERR(idle)) {
printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
return PTR_ERR(idle);
}
ci->idle = idle;
} else {
/*
* Since this idle thread is being re-used, call
* init_idle() to reinitialize the thread structure.
*/
init_idle(idle, cpu);
}
/*
* Allocate initial page tables to allow the new CPU to
* enable the MMU safely. This essentially means a set
* of our "standard" page tables, with the addition of
* a 1:1 mapping for the physical address of the kernel.
*/
pgd = pgd_alloc(&init_mm);
pmd = pmd_offset(pgd + pgd_index(PHYS_OFFSET), PHYS_OFFSET);
*pmd = __pmd((PHYS_OFFSET & PGDIR_MASK) |
PMD_TYPE_SECT | PMD_SECT_AP_WRITE);
flush_pmd_entry(pmd);
outer_clean_range(__pa(pmd), __pa(pmd + 1));
/*
* We need to tell the secondary core where to find
* its stack and the page tables.
*/
secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
secondary_data.pgdir = virt_to_phys(pgd);
__cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data));
outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1));
/*
* Now bring the CPU into our world.
*/
ret = boot_secondary(cpu, idle);
if (ret == 0) {
unsigned long timeout;
/*
* CPU was successfully started, wait for it
* to come online or time out.
*/
timeout = jiffies + HZ;
while (time_before(jiffies, timeout)) {
if (cpu_online(cpu))
break;
udelay(10);
barrier();
}
if (!cpu_online(cpu))
ret = -EIO;
}
secondary_data.stack = NULL;
secondary_data.pgdir = 0;
*pmd = __pmd(0);
clean_pmd_entry(pmd);
pgd_free(&init_mm, pgd);
if (ret) {
printk(KERN_CRIT "CPU%u: processor failed to boot\n", cpu);
/*
* FIXME: We need to clean up the new idle thread. --rmk
*/
}
return ret;
}
#ifdef CONFIG_HOTPLUG_CPU
/*
* __cpu_disable runs on the processor to be shutdown.
*/
int __cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
struct task_struct *p;
int ret;
ret = platform_cpu_disable(cpu);
if (ret)
return ret;
/*
* Take this CPU offline. Once we clear this, we can't return,
* and we must not schedule until we're ready to give up the cpu.
*/
set_cpu_online(cpu, false);
/*
* OK - migrate IRQs away from this CPU
*/
migrate_irqs();
/*
* Stop the local timer for this CPU.
*/
local_timer_stop();
/*
* Flush user cache and TLB mappings, and then remove this CPU
* from the vm mask set of all processes.
*/
flush_cache_all();
local_flush_tlb_all();
read_lock(&tasklist_lock);
for_each_process(p) {
if (p->mm)
cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
}
read_unlock(&tasklist_lock);
return 0;
}
/*
* called on the thread which is asking for a CPU to be shutdown -
* waits until shutdown has completed, or it is timed out.
*/
void __cpu_die(unsigned int cpu)
{
if (!platform_cpu_kill(cpu))
printk("CPU%u: unable to kill\n", cpu);
}
/*
* Called from the idle thread for the CPU which has been shutdown.
*
* Note that we disable IRQs here, but do not re-enable them
* before returning to the caller. This is also the behaviour
* of the other hotplug-cpu capable cores, so presumably coming
* out of idle fixes this.
*/
void __ref cpu_die(void)
{
unsigned int cpu = smp_processor_id();
local_irq_disable();
idle_task_exit();
/*
* actual CPU shutdown procedure is at least platform (if not
* CPU) specific
*/
platform_cpu_die(cpu);
/*
* Do not return to the idle loop - jump back to the secondary
* cpu initialisation. There's some initialisation which needs
* to be repeated to undo the effects of taking the CPU offline.
*/
__asm__("mov sp, %0\n"
" b secondary_start_kernel"
:
: "r" (task_stack_page(current) + THREAD_SIZE - 8));
}
#endif /* CONFIG_HOTPLUG_CPU */
/*
* This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables.
*/
asmlinkage void __cpuinit secondary_start_kernel(void)
{
struct mm_struct *mm = &init_mm;
unsigned int cpu = smp_processor_id();
printk("CPU%u: Booted secondary processor\n", cpu);
/*
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
atomic_inc(&mm->mm_users);
atomic_inc(&mm->mm_count);
current->active_mm = mm;
cpumask_set_cpu(cpu, mm_cpumask(mm));
cpu_switch_mm(mm->pgd, mm);
enter_lazy_tlb(mm, current);
local_flush_tlb_all();
cpu_init();
preempt_disable();
/*
* Give the platform a chance to do its own initialisation.
*/
platform_secondary_init(cpu);
/*
* Enable local interrupts.
*/
notify_cpu_starting(cpu);
local_irq_enable();
local_fiq_enable();
/*
* Setup the percpu timer for this CPU.
*/
percpu_timer_setup();
calibrate_delay();
smp_store_cpu_info(cpu);
/*
* OK, now it's safe to let the boot CPU continue
*/
set_cpu_online(cpu, true);
/*
* OK, it's off to the idle thread for us
*/
cpu_idle();
}
/*
* Called by both boot and secondaries to move global data into
* per-processor storage.
*/
void __cpuinit smp_store_cpu_info(unsigned int cpuid)
{
struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
cpu_info->loops_per_jiffy = loops_per_jiffy;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
int cpu;
unsigned long bogosum = 0;
for_each_online_cpu(cpu)
bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
printk(KERN_INFO "SMP: Total of %d processors activated "
"(%lu.%02lu BogoMIPS).\n",
num_online_cpus(),
bogosum / (500000/HZ),
(bogosum / (5000/HZ)) % 100);
}
void __init smp_prepare_boot_cpu(void)
{
unsigned int cpu = smp_processor_id();
per_cpu(cpu_data, cpu).idle = current;
}
static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg)
{
unsigned long flags;
unsigned int cpu;
local_irq_save(flags);
for_each_cpu(cpu, mask) {
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
spin_lock(&ipi->lock);
ipi->bits |= 1 << msg;
spin_unlock(&ipi->lock);
}
/*
* Call the platform specific cross-CPU call function.
*/
smp_cross_call(mask);
local_irq_restore(flags);
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
{
send_ipi_message(mask, IPI_CALL_FUNC);
}
void arch_send_call_function_single_ipi(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
}
void show_ipi_list(struct seq_file *p)
{
unsigned int cpu;
seq_puts(p, "IPI:");
for_each_present_cpu(cpu)
seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
seq_putc(p, '\n');
}
void show_local_irqs(struct seq_file *p)
{
unsigned int cpu;
seq_printf(p, "LOC: ");
for_each_present_cpu(cpu)
seq_printf(p, "%10u ", irq_stat[cpu].local_timer_irqs);
seq_putc(p, '\n');
}
/*
* Timer (local or broadcast) support
*/
static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent);
static void ipi_timer(void)
{
struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
irq_enter();
evt->event_handler(evt);
irq_exit();
}
#ifdef CONFIG_LOCAL_TIMERS
asmlinkage void __exception do_local_timer(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
int cpu = smp_processor_id();
if (local_timer_ack()) {
irq_stat[cpu].local_timer_irqs++;
ipi_timer();
}
set_irq_regs(old_regs);
}
#endif
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
static void smp_timer_broadcast(const struct cpumask *mask)
{
send_ipi_message(mask, IPI_TIMER);
}
#else
#define smp_timer_broadcast NULL
#endif
#ifndef CONFIG_LOCAL_TIMERS
static void broadcast_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
}
static void local_timer_setup(struct clock_event_device *evt)
{
evt->name = "dummy_timer";
evt->features = CLOCK_EVT_FEAT_ONESHOT |
CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_DUMMY;
evt->rating = 400;
evt->mult = 1;
evt->set_mode = broadcast_timer_set_mode;
clockevents_register_device(evt);
}
#endif
void __cpuinit percpu_timer_setup(void)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);
evt->cpumask = cpumask_of(cpu);
evt->broadcast = smp_timer_broadcast;
local_timer_setup(evt);
}
static DEFINE_SPINLOCK(stop_lock);
/*
* ipi_cpu_stop - handle IPI from smp_send_stop()
*/
static void ipi_cpu_stop(unsigned int cpu)
{
if (system_state == SYSTEM_BOOTING ||
system_state == SYSTEM_RUNNING) {
spin_lock(&stop_lock);
printk(KERN_CRIT "CPU%u: stopping\n", cpu);
dump_stack();
spin_unlock(&stop_lock);
}
set_cpu_online(cpu, false);
local_fiq_disable();
local_irq_disable();
while (1)
cpu_relax();
}
/*
* Main handler for inter-processor interrupts
*
* For ARM, the ipimask now only identifies a single
* category of IPI (Bit 1 IPIs have been replaced by a
* different mechanism):
*
* Bit 0 - Inter-processor function call
*/
asmlinkage void __exception do_IPI(struct pt_regs *regs)
{
unsigned int cpu = smp_processor_id();
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
struct pt_regs *old_regs = set_irq_regs(regs);
ipi->ipi_count++;
for (;;) {
unsigned long msgs;
spin_lock(&ipi->lock);
msgs = ipi->bits;
ipi->bits = 0;
spin_unlock(&ipi->lock);
if (!msgs)
break;
do {
unsigned nextmsg;
nextmsg = msgs & -msgs;
msgs &= ~nextmsg;
nextmsg = ffz(~nextmsg);
switch (nextmsg) {
case IPI_TIMER:
ipi_timer();
break;
case IPI_RESCHEDULE:
/*
* nothing more to do - eveything is
* done on the interrupt return path
*/
break;
case IPI_CALL_FUNC:
generic_smp_call_function_interrupt();
break;
case IPI_CALL_FUNC_SINGLE:
generic_smp_call_function_single_interrupt();
break;
case IPI_CPU_STOP:
ipi_cpu_stop(cpu);
break;
default:
printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
cpu, nextmsg);
break;
}
} while (msgs);
}
set_irq_regs(old_regs);
}
void smp_send_reschedule(int cpu)
{
send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
}
void smp_send_stop(void)
{
cpumask_t mask = cpu_online_map;
cpu_clear(smp_processor_id(), mask);
send_ipi_message(&mask, IPI_CPU_STOP);
}
/*
* not supported here
*/
int setup_profiling_timer(unsigned int multiplier)
{
return -EINVAL;
}
static void
on_each_cpu_mask(void (*func)(void *), void *info, int wait,
const struct cpumask *mask)
{
preempt_disable();
smp_call_function_many(mask, func, info, wait);
if (cpumask_test_cpu(smp_processor_id(), mask))
func(info);
preempt_enable();
}
/**********************************************************************/
/*
* TLB operations
*/
struct tlb_args {
struct vm_area_struct *ta_vma;
unsigned long ta_start;
unsigned long ta_end;
};
static inline void ipi_flush_tlb_all(void *ignored)
{
local_flush_tlb_all();
}
static inline void ipi_flush_tlb_mm(void *arg)
{
struct mm_struct *mm = (struct mm_struct *)arg;
local_flush_tlb_mm(mm);
}
static inline void ipi_flush_tlb_page(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_page(ta->ta_vma, ta->ta_start);
}
static inline void ipi_flush_tlb_kernel_page(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_kernel_page(ta->ta_start);
}
static inline void ipi_flush_tlb_range(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
}
static inline void ipi_flush_tlb_kernel_range(void *arg)
{
struct tlb_args *ta = (struct tlb_args *)arg;
local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
}
void flush_tlb_all(void)
{
if (tlb_ops_need_broadcast())
on_each_cpu(ipi_flush_tlb_all, NULL, 1);
else
local_flush_tlb_all();
}
void flush_tlb_mm(struct mm_struct *mm)
{
if (tlb_ops_need_broadcast())
on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mm_cpumask(mm));
else
local_flush_tlb_mm(mm);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_vma = vma;
ta.ta_start = uaddr;
on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mm_cpumask(vma->vm_mm));
} else
local_flush_tlb_page(vma, uaddr);
}
void flush_tlb_kernel_page(unsigned long kaddr)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_start = kaddr;
on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
} else
local_flush_tlb_kernel_page(kaddr);
}
void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_vma = vma;
ta.ta_start = start;
ta.ta_end = end;
on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mm_cpumask(vma->vm_mm));
} else
local_flush_tlb_range(vma, start, end);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
if (tlb_ops_need_broadcast()) {
struct tlb_args ta;
ta.ta_start = start;
ta.ta_end = end;
on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
} else
local_flush_tlb_kernel_range(start, end);
}