android_kernel_xiaomi_sm8350/arch/sh/kernel/smp.c
Manfred Spraul e545a6140b kernel/cpu.c: create a CPU_STARTING cpu_chain notifier
Right now, there is no notifier that is called on a new cpu, before the new
cpu begins processing interrupts/softirqs.
Various kernel function would need that notification, e.g. kvm works around
by calling smp_call_function_single(), rcu polls cpu_online_map.

The patch adds a CPU_STARTING notification. It also adds a helper function
that sends the message to all cpu_chain handlers.

Tested on x86-64.
All other archs are untested. Especially on sparc, I'm not sure if I got
it right.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-08 19:25:24 +02:00

335 lines
7.2 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 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();
notify_cpu_starting(smp_processor_id());
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, 0);
}
void arch_send_call_function_ipi(cpumask_t mask)
{
int cpu;
for_each_cpu_mask(cpu, mask)
plat_send_ipi(cpu, SMP_MSG_FUNCTION);
}
void arch_send_call_function_single_ipi(int cpu)
{
plat_send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
}
/* 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);
}
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);
} 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);
} 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);
}
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);
} 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);
local_flush_tlb_one(asid, vaddr);
}