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Commit 31a6b11f authored by Xiantao Zhang's avatar Xiantao Zhang Committed by Tony Luck
Browse files

[IA64] Implement smp_call_function_mask for ia64 



This interface provides more flexible functionality for smp
infrastructure ... e.g. KVM frequently needs to operate on
a subset of cpus.

Signed-off-by: default avatarXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 96651896

arch/ia64/kernel/smp.c

+82 −0
Original line number Diff line number Diff line
@@ -209,6 +209,19 @@ send_IPI_allbutself (int op) 
	}

}



/*

 * Called with preemption disabled.

 */

static inline void

send_IPI_mask(cpumask_t mask, int op)

{

	unsigned int cpu;



	for_each_cpu_mask(cpu, mask) {

			send_IPI_single(cpu, op);

	}

}



/*

 * Called with preemption disabled.

 */
@@ -401,6 +414,75 @@ smp_call_function_single (int cpuid, void (*func) (void *info), void *info, int 
}

EXPORT_SYMBOL(smp_call_function_single);



/**

 * 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)

{

	struct call_data_struct data;

	cpumask_t allbutself;

	int cpus;



	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;

	}



	/* Can deadlock when called with interrupts disabled */

	WARN_ON(irqs_disabled());



	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(); /* ensure store to call_data precedes setting of IPI_CALL_FUNC*/



	/* Send a message to other CPUs */

	if (cpus_equal(mask, allbutself))

		send_IPI_allbutself(IPI_CALL_FUNC);

	else

		send_IPI_mask(mask, IPI_CALL_FUNC);



	/* Wait for response */

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

		cpu_relax();



	if (wait)

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

			cpu_relax();

	call_data = NULL;



	spin_unlock(&call_lock);

	return 0;



}

EXPORT_SYMBOL(smp_call_function_mask);



/*

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

 * in the system.

include/asm-ia64/smp.h

+3 −0
Original line number Diff line number Diff line
@@ -38,6 +38,9 @@ ia64_get_lid (void) 
	return lid.f.id << 8 | lid.f.eid;

}



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

				  void *info, int wait);



#define hard_smp_processor_id()		ia64_get_lid()



#ifdef CONFIG_SMP