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Commit 3b16cf87 authored by Jens Axboe's avatar Jens Axboe
Browse files

x86: convert to generic helpers for IPI function calls 



This converts x86, x86-64, and xen to use the new helpers for
smp_call_function() and friends, and adds support for
smp_call_function_single().

Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 3d442233

arch/x86/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ config GENERIC_PENDING_IRQ 
config X86_SMP

	bool

	depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)

	select USE_GENERIC_SMP_HELPERS

	default y



config X86_32_SMP

arch/x86/kernel/apic_32.c

+4 −0
Original line number Diff line number Diff line
@@ -1358,6 +1358,10 @@ void __init smp_intr_init(void) 


	/* IPI for generic function call */

	set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);



	/* IPI for single call function */

	set_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,

				call_function_single_interrupt);

}

#endif

arch/x86/kernel/entry_64.S

+3 −0
Original line number Diff line number Diff line
@@ -711,6 +711,9 @@ END(invalidate_interrupt\num) 
ENTRY(call_function_interrupt)

	apicinterrupt CALL_FUNCTION_VECTOR,smp_call_function_interrupt

END(call_function_interrupt)

ENTRY(call_function_single_interrupt)

	apicinterrupt CALL_FUNCTION_SINGLE_VECTOR,smp_call_function_single_interrupt

END(call_function_single_interrupt)

ENTRY(irq_move_cleanup_interrupt)

	apicinterrupt IRQ_MOVE_CLEANUP_VECTOR,smp_irq_move_cleanup_interrupt

END(irq_move_cleanup_interrupt)

arch/x86/kernel/i8259_64.c

+4 −0
Original line number Diff line number Diff line
@@ -494,6 +494,10 @@ void __init native_init_IRQ(void) 
	/* IPI for generic function call */

	set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);



	/* IPI for generic single function call */

	set_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,

				call_function_single_interrupt);



	/* Low priority IPI to cleanup after moving an irq */

	set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);

#endif

arch/x86/kernel/smp.c

+20 −138
Original line number Diff line number Diff line
@@ -121,132 +121,23 @@ static void native_smp_send_reschedule(int 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)

void native_send_call_func_single_ipi(int cpu)

{

	spin_unlock_irq(&call_lock);

	send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_SINGLE_VECTOR);

}



static struct call_data_struct *call_data;



static void __smp_call_function(void (*func) (void *info), void *info,

				int nonatomic, int wait)

void native_send_call_func_ipi(cpumask_t mask)

{

	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) &&

	    cpus_equal(cpu_online_map, cpu_callout_map))

		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)
@@ -268,18 +159,13 @@ static void stop_this_cpu(void *dummy) 


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);

	smp_call_function(stop_this_cpu, NULL, 0, 0);

	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);

}
@@ -301,33 +187,28 @@ void smp_reschedule_interrupt(struct pt_regs *regs) 


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);

	generic_smp_call_function_interrupt();

#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);

}



void smp_call_function_single_interrupt(void)

{

	ack_APIC_irq();

	irq_enter();

	generic_smp_call_function_single_interrupt();

#ifdef CONFIG_X86_32

	__get_cpu_var(irq_stat).irq_call_count++;

#else

	add_pda(irq_call_count, 1);

#endif

	irq_exit();

}



struct smp_ops smp_ops = {
@@ -338,7 +219,8 @@ struct smp_ops smp_ops = { 


	.smp_send_stop = native_smp_send_stop,

	.smp_send_reschedule = native_smp_send_reschedule,

	.smp_call_function_mask = native_smp_call_function_mask,



	.send_call_func_ipi = native_send_call_func_ipi,

	.send_call_func_single_ipi = native_send_call_func_single_ipi,

};

EXPORT_SYMBOL_GPL(smp_ops);