#include <linux/init.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <linux/mc146818rtc.h>
#include <linux/cache.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <asm/mtrr.h>
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>
#include <asm/proto.h>
#ifdef CONFIG_X86_32
#include <mach_apic.h>
#include <mach_ipi.h>
#else
#include <asm/mach_apic.h>
#endif
/*
* this function sends a 'reschedule' IPI to another CPU.
* it goes straight through and wastes no time serializing
* anything. Worst case is that we lose a reschedule ...
*/
static void native_smp_send_reschedule(int cpu)
{
WARN_ON(cpu_is_offline(cpu));
send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
}
/*
* Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner.
*/
static DEFINE_SPINLOCK(call_lock);
struct call_data_struct {
void (*func) (void *info);
void *info;
atomic_t started;
atomic_t finished;
int wait;
};
void lock_ipi_call_lock(void)
{
spin_lock_irq(&call_lock);
}
void unlock_ipi_call_lock(void)
{
spin_unlock_irq(&call_lock);
}
static struct call_data_struct *call_data;
static void __smp_call_function(void (*func) (void *info), void *info,
int nonatomic, int wait)
{
struct call_data_struct data;
int cpus = num_online_cpus() - 1;
if (!cpus)
return;
data.func = func;
data.info = info;
atomic_set(&data.started, 0);
data.wait = wait;
if (wait)
atomic_set(&data.finished, 0);
call_data = &data;
mb();
/* Send a message to all other CPUs and wait for them to respond */
send_IPI_allbutself(CALL_FUNCTION_VECTOR);
/* Wait for response */
while (atomic_read(&data.started) != cpus)
cpu_relax();
if (wait)
while (atomic_read(&data.finished) != cpus)
cpu_relax();
}
/**
* smp_call_function_mask(): Run a function on a set of other CPUs.
* @mask: The set of cpus to run on. Must not include the current cpu.
* @func: The function to run. This must be fast and non-blocking.
* @info: An arbitrary pointer to pass to the function.
* @wait: If true, wait (atomically) until function has completed on other CPUs.
*
* Returns 0 on success, else a negative status code.
*
* If @wait is true, then returns once @func has returned; otherwise
* it returns just before the target cpu calls @func.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
static int
native_smp_call_function_mask(cpumask_t mask,
void (*func)(void *), void *info,
int wait)
{
struct call_data_struct data;
cpumask_t allbutself;
int cpus;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
/* Holding any lock stops cpus from going down. */
spin_lock(&call_lock);
allbutself = cpu_online_map;
cpu_clear(smp_processor_id(), allbutself);
cpus_and(mask, mask, allbutself);
cpus = cpus_weight(mask);
if (!cpus) {
spin_unlock(&call_lock);
return 0;
}
data.func = func;
data.info = info;
atomic_set(&data.started, 0);
data.wait = wait;
if (wait)
atomic_set(&data.finished, 0);
call_data = &data;
wmb();
/* Send a message to other CPUs */
if (cpus_equal(mask, allbutself))
send_IPI_allbutself(CALL_FUNCTION_VECTOR);
else
send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
/* Wait for response */
while (atomic_read(&data.started) != cpus)
cpu_relax();
if (wait)
while (atomic_read(&data.finished) != cpus)
cpu_relax();
spin_unlock(&call_lock);
return 0;
}
static void stop_this_cpu(void *dummy)
{
local_irq_disable();
/*
* Remove this CPU:
*/
cpu_clear(smp_processor_id(), cpu_online_map);
disable_local_APIC();
if (hlt_works(smp_processor_id()))
for (;;) halt();
for (;;);
}
/*
* this function calls the 'stop' function on all other CPUs in the system.
*/
static void native_smp_send_stop(void)
{
int nolock;
unsigned long flags;
if (reboot_force)
return;
/* Don't deadlock on the call lock in panic */
nolock = !spin_trylock(&call_lock);
local_irq_save(flags);
__smp_call_function(stop_this_cpu, NULL, 0, 0);
if (!nolock)
spin_unlock(&call_lock);
disable_local_APIC();
local_irq_restore(flags);
}
/*
* Reschedule call back. Nothing to do,
* all the work is done automatically when
* we return from the interrupt.
*/
void smp_reschedule_interrupt(struct pt_regs *regs)
{
ack_APIC_irq();
#ifdef CONFIG_X86_32
__get_cpu_var(irq_stat).irq_resched_count++;
#else
add_pda(irq_resched_count, 1);
#endif
}
void smp_call_function_interrupt(struct pt_regs *regs)
{
void (*func) (void *info) = call_data->func;
void *info = call_data->info;
int wait = call_data->wait;
ack_APIC_irq();
/*
* Notify initiating CPU that I've grabbed the data and am
* about to execute the function
*/
mb();
atomic_inc(&call_data->started);
/*
* At this point the info structure may be out of scope unless wait==1
*/
irq_enter();
(*func)(info);
#ifdef CONFIG_X86_32
__get_cpu_var(irq_stat).irq_call_count++;
#else
add_pda(irq_call_count, 1);
#endif
irq_exit();
if (wait) {
mb();
atomic_inc(&call_data->finished);
}
}
struct smp_ops smp_ops = {
.smp_prepare_boot_cpu = native_smp_prepare_boot_cpu,
.smp_prepare_cpus = native_smp_prepare_cpus,
.cpu_up = native_cpu_up,
.smp_cpus_done = native_smp_cpus_done,
.smp_send_stop = native_smp_send_stop,
.smp_send_reschedule = native_smp_send_reschedule,
.smp_call_function_mask = native_smp_call_function_mask,
};
EXPORT_SYMBOL_GPL(smp_ops);
