kernel-ark/arch/sh/kernel/smp.c
Paul Mundt aba1030a7e sh: Bring SMP support back from the dead.
There was a very preliminary bunch of SMP code scattered around for the
SH7604 microcontrollers from way back when, and it has mostly suffered
bitrot since then. With the tree already having been slowly getting
prepped for SMP, this plugs in most of the remaining platform-independent
bits.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-09-21 18:32:32 +09:00

365 lines
8.1 KiB
C

/*
* arch/sh/kernel/smp.c
*
* SMP support for the SuperH processors.
*
* Copyright (C) 2002 - 2007 Paul Mundt
* Copyright (C) 2006 - 2007 Akio Idehara
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/err.h>
#include <linux/cache.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <asm/atomic.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/mmu_context.h>
#include <asm/smp.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
cpumask_t cpu_possible_map;
EXPORT_SYMBOL(cpu_possible_map);
cpumask_t cpu_online_map;
EXPORT_SYMBOL(cpu_online_map);
static atomic_t cpus_booted = ATOMIC_INIT(0);
/*
* Run specified function on a particular processor.
*/
void __smp_call_function(unsigned int cpu);
static inline void __init smp_store_cpu_info(unsigned int cpu)
{
struct sh_cpuinfo *c = cpu_data + cpu;
c->loops_per_jiffy = loops_per_jiffy;
}
void __init smp_prepare_cpus(unsigned int max_cpus)
{
unsigned int cpu = smp_processor_id();
init_new_context(current, &init_mm);
current_thread_info()->cpu = cpu;
plat_prepare_cpus(max_cpus);
#ifndef CONFIG_HOTPLUG_CPU
cpu_present_map = cpu_possible_map;
#endif
}
void __devinit smp_prepare_boot_cpu(void)
{
unsigned int cpu = smp_processor_id();
__cpu_number_map[0] = cpu;
__cpu_logical_map[0] = cpu;
cpu_set(cpu, cpu_online_map);
cpu_set(cpu, cpu_possible_map);
}
asmlinkage void __cpuinit start_secondary(void)
{
unsigned int cpu;
struct mm_struct *mm = &init_mm;
atomic_inc(&mm->mm_count);
atomic_inc(&mm->mm_users);
current->active_mm = mm;
BUG_ON(current->mm);
enter_lazy_tlb(mm, current);
per_cpu_trap_init();
preempt_disable();
local_irq_enable();
calibrate_delay();
cpu = smp_processor_id();
smp_store_cpu_info(cpu);
cpu_set(cpu, cpu_online_map);
cpu_idle();
}
extern struct {
unsigned long sp;
unsigned long bss_start;
unsigned long bss_end;
void *start_kernel_fn;
void *cpu_init_fn;
void *thread_info;
} stack_start;
int __cpuinit __cpu_up(unsigned int cpu)
{
struct task_struct *tsk;
unsigned long timeout;
tsk = fork_idle(cpu);
if (IS_ERR(tsk)) {
printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
return PTR_ERR(tsk);
}
/* Fill in data in head.S for secondary cpus */
stack_start.sp = tsk->thread.sp;
stack_start.thread_info = tsk->stack;
stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
stack_start.start_kernel_fn = start_secondary;
flush_cache_all();
plat_start_cpu(cpu, (unsigned long)_stext);
timeout = jiffies + HZ;
while (time_before(jiffies, timeout)) {
if (cpu_online(cpu))
break;
udelay(10);
}
if (cpu_online(cpu))
return 0;
return -ENOENT;
}
void __init smp_cpus_done(unsigned int max_cpus)
{
unsigned long bogosum = 0;
int cpu;
for_each_online_cpu(cpu)
bogosum += 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 smp_send_reschedule(int cpu)
{
plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
}
static void stop_this_cpu(void *unused)
{
cpu_clear(smp_processor_id(), cpu_online_map);
local_irq_disable();
for (;;)
cpu_relax();
}
void smp_send_stop(void)
{
smp_call_function(stop_this_cpu, 0, 1, 0);
}
struct smp_fn_call_struct smp_fn_call = {
.lock = SPIN_LOCK_UNLOCKED,
.finished = ATOMIC_INIT(0),
};
/*
* The caller of this wants the passed function to run on every cpu. If wait
* is set, wait until all cpus have finished the function before returning.
* The lock is here to protect the call structure.
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
int smp_call_function(void (*func)(void *info), void *info, int retry, int wait)
{
unsigned int nr_cpus = atomic_read(&cpus_booted);
int i;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
spin_lock(&smp_fn_call.lock);
atomic_set(&smp_fn_call.finished, 0);
smp_fn_call.fn = func;
smp_fn_call.data = info;
for (i = 0; i < nr_cpus; i++)
if (i != smp_processor_id())
plat_send_ipi(i, SMP_MSG_FUNCTION);
if (wait)
while (atomic_read(&smp_fn_call.finished) != (nr_cpus - 1));
spin_unlock(&smp_fn_call.lock);
return 0;
}
/* Not really SMP stuff ... */
int setup_profiling_timer(unsigned int multiplier)
{
return 0;
}
static void flush_tlb_all_ipi(void *info)
{
local_flush_tlb_all();
}
void flush_tlb_all(void)
{
on_each_cpu(flush_tlb_all_ipi, 0, 1, 1);
}
static void flush_tlb_mm_ipi(void *mm)
{
local_flush_tlb_mm((struct mm_struct *)mm);
}
/*
* The following tlb flush calls are invoked when old translations are
* being torn down, or pte attributes are changing. For single threaded
* address spaces, a new context is obtained on the current cpu, and tlb
* context on other cpus are invalidated to force a new context allocation
* at switch_mm time, should the mm ever be used on other cpus. For
* multithreaded address spaces, intercpu interrupts have to be sent.
* Another case where intercpu interrupts are required is when the target
* mm might be active on another cpu (eg debuggers doing the flushes on
* behalf of debugees, kswapd stealing pages from another process etc).
* Kanoj 07/00.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
preempt_disable();
if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1, 1);
} else {
int i;
for (i = 0; i < num_online_cpus(); i++)
if (smp_processor_id() != i)
cpu_context(i, mm) = 0;
}
local_flush_tlb_mm(mm);
preempt_enable();
}
struct flush_tlb_data {
struct vm_area_struct *vma;
unsigned long addr1;
unsigned long addr2;
};
static void flush_tlb_range_ipi(void *info)
{
struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
}
void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
preempt_disable();
if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
struct flush_tlb_data fd;
fd.vma = vma;
fd.addr1 = start;
fd.addr2 = end;
smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1, 1);
} else {
int i;
for (i = 0; i < num_online_cpus(); i++)
if (smp_processor_id() != i)
cpu_context(i, mm) = 0;
}
local_flush_tlb_range(vma, start, end);
preempt_enable();
}
static void flush_tlb_kernel_range_ipi(void *info)
{
struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
struct flush_tlb_data fd;
fd.addr1 = start;
fd.addr2 = end;
on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1, 1);
}
static void flush_tlb_page_ipi(void *info)
{
struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
local_flush_tlb_page(fd->vma, fd->addr1);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
preempt_disable();
if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
(current->mm != vma->vm_mm)) {
struct flush_tlb_data fd;
fd.vma = vma;
fd.addr1 = page;
smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1, 1);
} else {
int i;
for (i = 0; i < num_online_cpus(); i++)
if (smp_processor_id() != i)
cpu_context(i, vma->vm_mm) = 0;
}
local_flush_tlb_page(vma, page);
preempt_enable();
}
static void flush_tlb_one_ipi(void *info)
{
struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
local_flush_tlb_one(fd->addr1, fd->addr2);
}
void flush_tlb_one(unsigned long asid, unsigned long vaddr)
{
struct flush_tlb_data fd;
fd.addr1 = asid;
fd.addr2 = vaddr;
smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1, 1);
local_flush_tlb_one(asid, vaddr);
}