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Commit 66d16ed4 authored by Laurent Vivier's avatar Laurent Vivier Committed by Thomas Gleixner
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x86: implement missing x86_64 function smp_call_function_mask() 



This patch defines the missing function smp_call_function_mask() for x86_64,
this is more or less a cut&paste of i386 function. It removes also some
duplicate code.

This function is needed by KVM to execute a function on some CPUs.

AK: Fixed description
AK: Moved WARN_ON(irqs_disabled) one level up to not warn in the panic case.
[ tglx: arch/x86 adaptation ]

Signed-off-by: default avatarLaurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 9d1c6e7c

arch/x86/kernel/smp_64.c

+63 −56
Original line number Diff line number Diff line
@@ -322,17 +322,27 @@ void unlock_ipi_call_lock(void) 
}



/*

 * this function sends a 'generic call function' IPI to one other CPU

 * in the system.

 *

 * cpu is a standard Linux logical CPU number.

 * this function sends a 'generic call function' IPI to all other CPU

 * of the system defined in the mask.

 */

static void

__smp_call_function_single(int cpu, void (*func) (void *info), void *info,

				int nonatomic, int wait)



static int

__smp_call_function_mask(cpumask_t mask,

			 void (*func)(void *), void *info,

			 int wait)

{

	struct call_data_struct data;

	int cpus = 1;

	cpumask_t allbutself;

	int cpus;



	allbutself = cpu_online_map;

	cpu_clear(smp_processor_id(), allbutself);



	cpus_and(mask, mask, allbutself);

	cpus = cpus_weight(mask);



	if (!cpus)

		return 0;



	data.func = func;

	data.info = info;
@@ -343,19 +353,55 @@ __smp_call_function_single(int cpu, void (*func) (void *info), void *info, 


	call_data = &data;

	wmb();

	/* Send a message to all other CPUs and wait for them to respond */

	send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_VECTOR);



	/* 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)

		return;

		return 0;



	while (atomic_read(&data.finished) != cpus)

		cpu_relax();



	return 0;

}

/**

 * 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.

 */

int smp_call_function_mask(cpumask_t mask,

			   void (*func)(void *), void *info,

			   int wait)

{

	int ret;



	/* Can deadlock when called with interrupts disabled */

	WARN_ON(irqs_disabled());



	spin_lock(&call_lock);

	ret = __smp_call_function_mask(mask, func, info, wait);

	spin_unlock(&call_lock);

	return ret;

}

EXPORT_SYMBOL(smp_call_function_mask);



/*

 * smp_call_function_single - Run a function on a specific CPU
@@ -374,6 +420,7 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info, 
	int nonatomic, int wait)

{

	/* prevent preemption and reschedule on another processor */

	int ret;

	int me = get_cpu();



	/* Can deadlock when called with interrupts disabled */
@@ -387,50 +434,13 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info, 
		return 0;

	}



	spin_lock(&call_lock);

	__smp_call_function_single(cpu, func, info, nonatomic, wait);

	spin_unlock(&call_lock);

	ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);



	put_cpu();

	return 0;

	return ret;

}

EXPORT_SYMBOL(smp_call_function_single);



/*

 * this function sends a 'generic call function' IPI to all other CPUs

 * in the system.

 */

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;

	wmb();

	/* 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)

		return;



	while (atomic_read(&data.finished) != cpus)

		cpu_relax();

}



/*

 * smp_call_function - run a function on all other CPUs.

 * @func: The function to run. This must be fast and non-blocking.
@@ -449,10 +459,7 @@ static void __smp_call_function (void (*func) (void *info), void *info, 
int smp_call_function (void (*func) (void *info), void *info, int nonatomic,

			int wait)

{

	spin_lock(&call_lock);

	__smp_call_function(func,info,nonatomic,wait);

	spin_unlock(&call_lock);

	return 0;

	return smp_call_function_mask(cpu_online_map, func, info, wait);

}

EXPORT_SYMBOL(smp_call_function);
@@ -479,7 +486,7 @@ void smp_send_stop(void) 
	/* 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);

	__smp_call_function_mask(cpu_online_map, stop_this_cpu, NULL, 0);

	if (!nolock)

		spin_unlock(&call_lock);

	disable_local_APIC();

include/asm-x86/smp_64.h

+2 −0
Original line number Diff line number Diff line
@@ -37,6 +37,8 @@ extern void lock_ipi_call_lock(void); 
extern void unlock_ipi_call_lock(void);

extern int smp_num_siblings;

extern void smp_send_reschedule(int cpu);

extern int smp_call_function_mask(cpumask_t mask, void (*func)(void *),

				  void *info, int wait);



/*

 * cpu_sibling_map and cpu_core_map now live