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Commit f27b433e authored by Jens Axboe's avatar Jens Axboe
Browse files

ia64: convert to generic helpers for IPI function calls 



This converts ia64 to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single().

Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent b7d7a240

arch/ia64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -303,6 +303,7 @@ config VIRT_CPU_ACCOUNTING 


config SMP

	bool "Symmetric multi-processing support"

	select USE_GENERIC_SMP_HELPERS

	help

	  This enables support for systems with more than one CPU. If you have

	  a system with only one CPU, say N.  If you have a system with more

arch/ia64/kernel/smp.c

+13 −237
Original line number Diff line number Diff line
@@ -60,25 +60,9 @@ static struct local_tlb_flush_counts { 


static DEFINE_PER_CPU(unsigned int, shadow_flush_counts[NR_CPUS]) ____cacheline_aligned;





/*

 * Structure and data for smp_call_function(). This is designed to minimise static memory

 * requirements. It also looks cleaner.

 */

static  __cacheline_aligned DEFINE_SPINLOCK(call_lock);



struct call_data_struct {

	void (*func) (void *info);

	void *info;

	long wait;

	atomic_t started;

	atomic_t finished;

};



static volatile struct call_data_struct *call_data;



#define IPI_CALL_FUNC		0

#define IPI_CPU_STOP		1

#define IPI_CALL_FUNC_SINGLE	2

#define IPI_KDUMP_CPU_STOP	3



/* This needs to be cacheline aligned because it is written to by *other* CPUs.  */
@@ -86,43 +70,6 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(u64, ipi_operation); 


extern void cpu_halt (void);



void

lock_ipi_calllock(void)

{

	spin_lock_irq(&call_lock);

}



void

unlock_ipi_calllock(void)

{

	spin_unlock_irq(&call_lock);

}



static inline void

handle_call_data(void)

{

	struct call_data_struct *data;

	void (*func)(void *info);

	void *info;

	int wait;



	/* release the 'pointer lock' */

	data = (struct call_data_struct *)call_data;

	func = data->func;

	info = data->info;

	wait = data->wait;



	mb();

	atomic_inc(&data->started);

	/* At this point the structure may be gone unless wait is true. */

	(*func)(info);



	/* Notify the sending CPU that the task is done. */

	mb();

	if (wait)

		atomic_inc(&data->finished);

}



static void

stop_this_cpu(void)

{
@@ -163,13 +110,15 @@ handle_IPI (int irq, void *dev_id) 
			ops &= ~(1 << which);



			switch (which) {

			case IPI_CALL_FUNC:

				handle_call_data();

				break;



			case IPI_CPU_STOP:

				stop_this_cpu();

				break;

			case IPI_CALL_FUNC:

				generic_smp_call_function_interrupt();

				break;

			case IPI_CALL_FUNC_SINGLE:

				generic_smp_call_function_single_interrupt();

				break;

#ifdef CONFIG_KEXEC

			case IPI_KDUMP_CPU_STOP:

				unw_init_running(kdump_cpu_freeze, NULL);
@@ -187,6 +136,8 @@ handle_IPI (int irq, void *dev_id) 
	return IRQ_HANDLED;

}







/*

 * Called with preemption disabled.

 */
@@ -360,190 +311,15 @@ smp_flush_tlb_mm (struct mm_struct *mm) 
	on_each_cpu((void (*)(void *))local_finish_flush_tlb_mm, mm, 1, 1);

}



/*

 * Run a function on a specific CPU

 *  <func>	The function to run. This must be fast and non-blocking.

 *  <info>	An arbitrary pointer to pass to the function.

 *  <nonatomic>	Currently unused.

 *  <wait>	If true, wait until function has completed on other CPUs.

 *  [RETURNS]   0 on success, else a negative status code.

 *

 * Does not return until the remote CPU is nearly ready to execute <func>

 * or is or has executed.

 */



int

smp_call_function_single (int cpuid, void (*func) (void *info), void *info, int nonatomic,

			  int wait)

void arch_send_call_function_single_ipi(int cpu)

{

	struct call_data_struct data;

	int cpus = 1;

	int me = get_cpu(); /* prevent preemption and reschedule on another processor */



	if (cpuid == me) {

		local_irq_disable();

		func(info);

		local_irq_enable();

		put_cpu();

		return 0;

	send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);

}



	data.func = func;

	data.info = info;

	atomic_set(&data.started, 0);

	data.wait = wait;

	if (wait)

		atomic_set(&data.finished, 0);



	spin_lock_bh(&call_lock);



	call_data = &data;

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

  	send_IPI_single(cpuid, 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_bh(&call_lock);

	put_cpu();

	return 0;

}

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)

void arch_send_call_function_ipi(cpumask_t mask)

{

	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.

 */



/*

 *  [SUMMARY]	Run a function on all other CPUs.

 *  <func>	The function to run. This must be fast and non-blocking.

 *  <info>	An arbitrary pointer to pass to the function.

 *  <nonatomic>	currently unused.

 *  <wait>	If true, wait (atomically) until function has completed on other CPUs.

 *  [RETURNS]   0 on success, else a negative status code.

 *

 * Does not return until remote CPUs are nearly ready to execute <func> or are or have

 * executed.

 *

 * 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 (void (*func) (void *info), void *info, int nonatomic, int wait)

{

	struct call_data_struct data;

	int cpus;



	spin_lock(&call_lock);

	cpus = num_online_cpus() - 1;

	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_IPI_allbutself(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);



/*

 * this function calls the 'stop' function on all other CPUs in the system.

arch/ia64/kernel/smpboot.c

+2 −2
Original line number Diff line number Diff line
@@ -395,14 +395,14 @@ smp_callin (void) 


	fix_b0_for_bsp();



	lock_ipi_calllock();

	ipi_call_lock_irq();

	spin_lock(&vector_lock);

	/* Setup the per cpu irq handling data structures */

	__setup_vector_irq(cpuid);

	cpu_set(cpuid, cpu_online_map);

	per_cpu(cpu_state, cpuid) = CPU_ONLINE;

	spin_unlock(&vector_lock);

	unlock_ipi_calllock();

	ipi_call_unlock_irq();



	smp_setup_percpu_timer();

include/asm-ia64/smp.h

+3 −5
Original line number Diff line number Diff line
@@ -38,9 +38,6 @@ 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
@@ -124,11 +121,12 @@ extern void __init init_smp_config (void); 
extern void smp_do_timer (struct pt_regs *regs);



extern void smp_send_reschedule (int cpu);

extern void lock_ipi_calllock(void);

extern void unlock_ipi_calllock(void);

extern void identify_siblings (struct cpuinfo_ia64 *);

extern int is_multithreading_enabled(void);



extern void arch_send_call_function_single_ipi(int cpu);

extern void arch_send_call_function_ipi(cpumask_t mask);



#else /* CONFIG_SMP */



#define cpu_logical_id(i)		0