arch/blackfin/mach-common/smp.c - kernel/msm-4.9 - Gitiles

 /*
  * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
  *
  * Copyright 2007-2009 Analog Devices Inc.
  *                         Philippe Gerum <rpm@xenomai.org>
  *
  * Licensed under the GPL-2.
  */

 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/sched.h>
 #include <linux/interrupt.h>
 #include <linux/cache.h>
 #include <linux/profile.h>
 #include <linux/errno.h>
 #include <linux/mm.h>
 #include <linux/cpu.h>
 #include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/seq_file.h>
 #include <linux/irq.h>
 #include <linux/slab.h>
 #include <asm/atomic.h>
 #include <asm/cacheflush.h>
 #include <asm/mmu_context.h>
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 #include <asm/cpu.h>
 #include <asm/time.h>
 #include <linux/err.h>

 /*
  * Anomaly notes:
  * 05000120 - we always define corelock as 32-bit integer in L2
  */
 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));

 #ifdef CONFIG_ICACHE_FLUSH_L1
 unsigned long blackfin_iflush_l1_entry[NR_CPUS];
 #endif

 void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
 	*init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
 	*init_saved_dcplb_fault_addr_coreb;

 #define BFIN_IPI_RESCHEDULE   0
 #define BFIN_IPI_CALL_FUNC    1
 #define BFIN_IPI_CPU_STOP     2

 struct blackfin_flush_data {
 	unsigned long start;
 	unsigned long end;
 };

 void *secondary_stack;


 struct smp_call_struct {
 	void (*func)(void *info);
 	void *info;
 	int wait;
 	cpumask_t *waitmask;
 };

 static struct blackfin_flush_data smp_flush_data;

 static DEFINE_SPINLOCK(stop_lock);

 struct ipi_message {
 	unsigned long type;
 	struct smp_call_struct call_struct;
 };

 /* A magic number - stress test shows this is safe for common cases */
 #define BFIN_IPI_MSGQ_LEN 5

 /* Simple FIFO buffer, overflow leads to panic */
 struct ipi_message_queue {
 	spinlock_t lock;
 	unsigned long count;
 	unsigned long head; /* head of the queue */
 	struct ipi_message ipi_message[BFIN_IPI_MSGQ_LEN];
 };

 static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);

 static void ipi_cpu_stop(unsigned int cpu)
 {
 	spin_lock(&stop_lock);
 	printk(KERN_CRIT "CPU%u: stopping\n", cpu);
 	dump_stack();
 	spin_unlock(&stop_lock);

 	cpu_clear(cpu, cpu_online_map);

 	local_irq_disable();

 	while (1)
 		SSYNC();
 }

 static void ipi_flush_icache(void *info)
 {
 	struct blackfin_flush_data *fdata = info;

 	/* Invalidate the memory holding the bounds of the flushed region. */
 	invalidate_dcache_range((unsigned long)fdata,
 		(unsigned long)fdata + sizeof(*fdata));

 	flush_icache_range(fdata->start, fdata->end);
 }

 static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
 {
 	int wait;
 	void (*func)(void *info);
 	void *info;
 	func = msg->call_struct.func;
 	info = msg->call_struct.info;
 	wait = msg->call_struct.wait;
 	func(info);
 	if (wait) {
 #ifdef __ARCH_SYNC_CORE_DCACHE
 		/*
 		 * 'wait' usually means synchronization between CPUs.
 		 * Invalidate D cache in case shared data was changed
 		 * by func() to ensure cache coherence.
 		 */
 		resync_core_dcache();
 #endif
 		cpu_clear(cpu, *msg->call_struct.waitmask);
 	}
 }

 /* Use IRQ_SUPPLE_0 to request reschedule.
  * When returning from interrupt to user space,
  * there is chance to reschedule */
 static irqreturn_t ipi_handler_int0(int irq, void *dev_instance)
 {
 	unsigned int cpu = smp_processor_id();

 	platform_clear_ipi(cpu, IRQ_SUPPLE_0);
 	return IRQ_HANDLED;
 }

 static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
 {
 	struct ipi_message *msg;
 	struct ipi_message_queue *msg_queue;
 	unsigned int cpu = smp_processor_id();
 	unsigned long flags;

 	platform_clear_ipi(cpu, IRQ_SUPPLE_1);

 	msg_queue = &__get_cpu_var(ipi_msg_queue);

 	spin_lock_irqsave(&msg_queue->lock, flags);

 	while (msg_queue->count) {
 		msg = &msg_queue->ipi_message[msg_queue->head];
 		switch (msg->type) {
 		case BFIN_IPI_CALL_FUNC:
 			spin_unlock_irqrestore(&msg_queue->lock, flags);
 			ipi_call_function(cpu, msg);
 			spin_lock_irqsave(&msg_queue->lock, flags);
 			break;
 		case BFIN_IPI_CPU_STOP:
 			spin_unlock_irqrestore(&msg_queue->lock, flags);
 			ipi_cpu_stop(cpu);
 			spin_lock_irqsave(&msg_queue->lock, flags);
 			break;
 		default:
 			printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%lx\n",
 			       cpu, msg->type);
 			break;
 		}
 		msg_queue->head++;
 		msg_queue->head %= BFIN_IPI_MSGQ_LEN;
 		msg_queue->count--;
 	}
 	spin_unlock_irqrestore(&msg_queue->lock, flags);
 	return IRQ_HANDLED;
 }

 static void ipi_queue_init(void)
 {
 	unsigned int cpu;
 	struct ipi_message_queue *msg_queue;
 	for_each_possible_cpu(cpu) {
 		msg_queue = &per_cpu(ipi_msg_queue, cpu);
 		spin_lock_init(&msg_queue->lock);
 		msg_queue->count = 0;
 		msg_queue->head = 0;
 	}
 }

 static inline void smp_send_message(cpumask_t callmap, unsigned long type,
 					void (*func) (void *info), void *info, int wait)
 {
 	unsigned int cpu;
 	struct ipi_message_queue *msg_queue;
 	struct ipi_message *msg;
 	unsigned long flags, next_msg;
 	cpumask_t waitmask = callmap; /* waitmask is shared by all cpus */

 	for_each_cpu_mask(cpu, callmap) {
 		msg_queue = &per_cpu(ipi_msg_queue, cpu);
 		spin_lock_irqsave(&msg_queue->lock, flags);
 		if (msg_queue->count < BFIN_IPI_MSGQ_LEN) {
 			next_msg = (msg_queue->head + msg_queue->count)
 					% BFIN_IPI_MSGQ_LEN;
 			msg = &msg_queue->ipi_message[next_msg];
 			msg->type = type;
 			if (type == BFIN_IPI_CALL_FUNC) {
 				msg->call_struct.func = func;
 				msg->call_struct.info = info;
 				msg->call_struct.wait = wait;
 				msg->call_struct.waitmask = &waitmask;
 			}
 			msg_queue->count++;
 		} else
 			panic("IPI message queue overflow\n");
 		spin_unlock_irqrestore(&msg_queue->lock, flags);
 		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
 	}

 	if (wait) {
 		while (!cpus_empty(waitmask))
 			blackfin_dcache_invalidate_range(
 				(unsigned long)(&waitmask),
 				(unsigned long)(&waitmask));
 #ifdef __ARCH_SYNC_CORE_DCACHE
 		/*
 		 * Invalidate D cache in case shared data was changed by
 		 * other processors to ensure cache coherence.
 		 */
 		resync_core_dcache();
 #endif
 	}
 }

 int smp_call_function(void (*func)(void *info), void *info, int wait)
 {
 	cpumask_t callmap;

 	preempt_disable();
 	callmap = cpu_online_map;
 	cpu_clear(smp_processor_id(), callmap);
 	if (!cpus_empty(callmap))
 		smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);

 	preempt_enable();

 	return 0;
 }
 EXPORT_SYMBOL_GPL(smp_call_function);

 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 				int wait)
 {
 	unsigned int cpu = cpuid;
 	cpumask_t callmap;

 	if (cpu_is_offline(cpu))
 		return 0;
 	cpus_clear(callmap);
 	cpu_set(cpu, callmap);

 	smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(smp_call_function_single);

 void smp_send_reschedule(int cpu)
 {
 	/* simply trigger an ipi */
 	if (cpu_is_offline(cpu))
 		return;
 	platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);

 	return;
 }

 void smp_send_stop(void)
 {
 	cpumask_t callmap;

 	preempt_disable();
 	callmap = cpu_online_map;
 	cpu_clear(smp_processor_id(), callmap);
 	if (!cpus_empty(callmap))
 		smp_send_message(callmap, BFIN_IPI_CPU_STOP, NULL, NULL, 0);

 	preempt_enable();

 	return;
 }

 int __cpuinit __cpu_up(unsigned int cpu)
 {
 	int ret;
 	static struct task_struct *idle;

 	if (idle)
 		free_task(idle);

 	idle = fork_idle(cpu);
 	if (IS_ERR(idle)) {
 		printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 		return PTR_ERR(idle);
 	}

 	secondary_stack = task_stack_page(idle) + THREAD_SIZE;

 	ret = platform_boot_secondary(cpu, idle);

 	secondary_stack = NULL;

 	return ret;
 }

 static void __cpuinit setup_secondary(unsigned int cpu)
 {
 	unsigned long ilat;

 	bfin_write_IMASK(0);
 	CSYNC();
 	ilat = bfin_read_ILAT();
 	CSYNC();
 	bfin_write_ILAT(ilat);
 	CSYNC();

 	/* Enable interrupt levels IVG7-15. IARs have been already
 	 * programmed by the boot CPU.  */
 	bfin_irq_flags |= IMASK_IVG15 |
 	    IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
 	    IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
 }

 void __cpuinit secondary_start_kernel(void)
 {
 	unsigned int cpu = smp_processor_id();
 	struct mm_struct *mm = &init_mm;

 	if (_bfin_swrst & SWRST_DBL_FAULT_B) {
 		printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 		printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
 			(int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
 		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
 		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
 #endif
 		printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
 			init_retx_coreb);
 	}

 	/*
 	 * We want the D-cache to be enabled early, in case the atomic
 	 * support code emulates cache coherence (see
 	 * __ARCH_SYNC_CORE_DCACHE).
 	 */
 	init_exception_vectors();

 	local_irq_disable();

 	/* Attach the new idle task to the global mm. */
 	atomic_inc(&mm->mm_users);
 	atomic_inc(&mm->mm_count);
 	current->active_mm = mm;

 	preempt_disable();

 	setup_secondary(cpu);

 	platform_secondary_init(cpu);

 	/* setup local core timer */
 	bfin_local_timer_setup();

 	local_irq_enable();

 	bfin_setup_caches(cpu);

 	/*
 	 * Calibrate loops per jiffy value.
 	 * IRQs need to be enabled here - D-cache can be invalidated
 	 * in timer irq handler, so core B can read correct jiffies.
 	 */
 	calibrate_delay();

 	cpu_idle();
 }

 void __init smp_prepare_boot_cpu(void)
 {
 }

 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
 	platform_prepare_cpus(max_cpus);
 	ipi_queue_init();
 	platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0);
 	platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1);
 }

 void __init smp_cpus_done(unsigned int max_cpus)
 {
 	unsigned long bogosum = 0;
 	unsigned int cpu;

 	for_each_online_cpu(cpu)
 		bogosum += loops_per_jiffy;

 	printk(KERN_INFO "SMP: Total of %d processors activated "
 	       "(%lu.%02lu BogoMIPS).\n",
 	       num_online_cpus(),
 	       bogosum / (500000/HZ),
 	       (bogosum / (5000/HZ)) % 100);
 }

 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
 {
 	smp_flush_data.start = start;
 	smp_flush_data.end = end;

 	if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
 		printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
 }
 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);

 #ifdef __ARCH_SYNC_CORE_ICACHE
 unsigned long icache_invld_count[NR_CPUS];
 void resync_core_icache(void)
 {
 	unsigned int cpu = get_cpu();
 	blackfin_invalidate_entire_icache();
 	icache_invld_count[cpu]++;
 	put_cpu();
 }
 EXPORT_SYMBOL(resync_core_icache);
 #endif

 #ifdef __ARCH_SYNC_CORE_DCACHE
 unsigned long dcache_invld_count[NR_CPUS];
 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));

 void resync_core_dcache(void)
 {
 	unsigned int cpu = get_cpu();
 	blackfin_invalidate_entire_dcache();
 	dcache_invld_count[cpu]++;
 	put_cpu();
 }
 EXPORT_SYMBOL(resync_core_dcache);
 #endif

 #ifdef CONFIG_HOTPLUG_CPU
 int __cpuexit __cpu_disable(void)
 {
 	unsigned int cpu = smp_processor_id();

 	if (cpu == 0)
 		return -EPERM;

 	set_cpu_online(cpu, false);
 	return 0;
 }

 static DECLARE_COMPLETION(cpu_killed);

 int __cpuexit __cpu_die(unsigned int cpu)
 {
 	return wait_for_completion_timeout(&cpu_killed, 5000);
 }

 void cpu_die(void)
 {
 	complete(&cpu_killed);

 	atomic_dec(&init_mm.mm_users);
 	atomic_dec(&init_mm.mm_count);

 	local_irq_disable();
 	platform_cpu_die();
 }
 #endif
	/*
	* IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
	*
	* Copyright 2007-2009 Analog Devices Inc.
	* Philippe Gerum <rpm@xenomai.org>
	*
	* Licensed under the GPL-2.
	*/

	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/init.h>
	#include <linux/spinlock.h>
	#include <linux/sched.h>
	#include <linux/interrupt.h>
	#include <linux/cache.h>
	#include <linux/profile.h>
	#include <linux/errno.h>
	#include <linux/mm.h>
	#include <linux/cpu.h>
	#include <linux/smp.h>
	#include <linux/cpumask.h>
	#include <linux/seq_file.h>
	#include <linux/irq.h>
	#include <linux/slab.h>
	#include <asm/atomic.h>
	#include <asm/cacheflush.h>
	#include <asm/mmu_context.h>
	#include <asm/pgtable.h>
	#include <asm/pgalloc.h>
	#include <asm/processor.h>
	#include <asm/ptrace.h>
	#include <asm/cpu.h>
	#include <asm/time.h>
	#include <linux/err.h>

	/*
	* Anomaly notes:
	* 05000120 - we always define corelock as 32-bit integer in L2
	*/
	struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));

	#ifdef CONFIG_ICACHE_FLUSH_L1
	unsigned long blackfin_iflush_l1_entry[NR_CPUS];
	#endif

	void __cpuinitdata init_retx_coreb, init_saved_retx_coreb,
	init_saved_seqstat_coreb, init_saved_icplb_fault_addr_coreb,
	*init_saved_dcplb_fault_addr_coreb;

	#define BFIN_IPI_RESCHEDULE 0
	#define BFIN_IPI_CALL_FUNC 1
	#define BFIN_IPI_CPU_STOP 2

	struct blackfin_flush_data {
	unsigned long start;
	unsigned long end;
	};

	void *secondary_stack;


	struct smp_call_struct {
	void (func)(void info);
	void *info;
	int wait;
	cpumask_t *waitmask;
	};

	static struct blackfin_flush_data smp_flush_data;

	static DEFINE_SPINLOCK(stop_lock);

	struct ipi_message {
	unsigned long type;
	struct smp_call_struct call_struct;
	};

	/* A magic number - stress test shows this is safe for common cases */
	#define BFIN_IPI_MSGQ_LEN 5

	/* Simple FIFO buffer, overflow leads to panic */
	struct ipi_message_queue {
	spinlock_t lock;
	unsigned long count;
	unsigned long head; /* head of the queue */
	struct ipi_message ipi_message[BFIN_IPI_MSGQ_LEN];
	};

	static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);

	static void ipi_cpu_stop(unsigned int cpu)
	{
	spin_lock(&stop_lock);
	printk(KERN_CRIT "CPU%u: stopping\n", cpu);
	dump_stack();
	spin_unlock(&stop_lock);

	cpu_clear(cpu, cpu_online_map);

	local_irq_disable();

	while (1)
	SSYNC();
	}

	static void ipi_flush_icache(void *info)
	{
	struct blackfin_flush_data *fdata = info;

	/* Invalidate the memory holding the bounds of the flushed region. */
	invalidate_dcache_range((unsigned long)fdata,
	(unsigned long)fdata + sizeof(*fdata));

	flush_icache_range(fdata->start, fdata->end);
	}

	static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
	{
	int wait;
	void (func)(void info);
	void *info;
	func = msg->call_struct.func;
	info = msg->call_struct.info;
	wait = msg->call_struct.wait;
	func(info);
	if (wait) {
	#ifdef __ARCH_SYNC_CORE_DCACHE
	/*
	* 'wait' usually means synchronization between CPUs.
	* Invalidate D cache in case shared data was changed
	* by func() to ensure cache coherence.
	*/
	resync_core_dcache();
	#endif
	cpu_clear(cpu, *msg->call_struct.waitmask);
	}
	}

	/* Use IRQ_SUPPLE_0 to request reschedule.
	* When returning from interrupt to user space,
	* there is chance to reschedule */
	static irqreturn_t ipi_handler_int0(int irq, void *dev_instance)
	{
	unsigned int cpu = smp_processor_id();

	platform_clear_ipi(cpu, IRQ_SUPPLE_0);
	return IRQ_HANDLED;
	}

	static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
	{
	struct ipi_message *msg;
	struct ipi_message_queue *msg_queue;
	unsigned int cpu = smp_processor_id();
	unsigned long flags;

	platform_clear_ipi(cpu, IRQ_SUPPLE_1);

	msg_queue = &__get_cpu_var(ipi_msg_queue);

	spin_lock_irqsave(&msg_queue->lock, flags);

	while (msg_queue->count) {
	msg = &msg_queue->ipi_message[msg_queue->head];
	switch (msg->type) {
	case BFIN_IPI_CALL_FUNC:
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	ipi_call_function(cpu, msg);
	spin_lock_irqsave(&msg_queue->lock, flags);
	break;
	case BFIN_IPI_CPU_STOP:
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	ipi_cpu_stop(cpu);
	spin_lock_irqsave(&msg_queue->lock, flags);
	break;
	default:
	printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%lx\n",
	cpu, msg->type);
	break;
	}
	msg_queue->head++;
	msg_queue->head %= BFIN_IPI_MSGQ_LEN;
	msg_queue->count--;
	}
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	return IRQ_HANDLED;
	}

	static void ipi_queue_init(void)
	{
	unsigned int cpu;
	struct ipi_message_queue *msg_queue;
	for_each_possible_cpu(cpu) {
	msg_queue = &per_cpu(ipi_msg_queue, cpu);
	spin_lock_init(&msg_queue->lock);
	msg_queue->count = 0;
	msg_queue->head = 0;
	}
	}

	static inline void smp_send_message(cpumask_t callmap, unsigned long type,
	void (func) (void info), void *info, int wait)
	{
	unsigned int cpu;
	struct ipi_message_queue *msg_queue;
	struct ipi_message *msg;
	unsigned long flags, next_msg;
	cpumask_t waitmask = callmap; /* waitmask is shared by all cpus */

	for_each_cpu_mask(cpu, callmap) {
	msg_queue = &per_cpu(ipi_msg_queue, cpu);
	spin_lock_irqsave(&msg_queue->lock, flags);
	if (msg_queue->count < BFIN_IPI_MSGQ_LEN) {
	next_msg = (msg_queue->head + msg_queue->count)
	% BFIN_IPI_MSGQ_LEN;
	msg = &msg_queue->ipi_message[next_msg];
	msg->type = type;
	if (type == BFIN_IPI_CALL_FUNC) {
	msg->call_struct.func = func;
	msg->call_struct.info = info;
	msg->call_struct.wait = wait;
	msg->call_struct.waitmask = &waitmask;
	}
	msg_queue->count++;
	} else
	panic("IPI message queue overflow\n");
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
	}

	if (wait) {
	while (!cpus_empty(waitmask))
	blackfin_dcache_invalidate_range(
	(unsigned long)(&waitmask),
	(unsigned long)(&waitmask));
	#ifdef __ARCH_SYNC_CORE_DCACHE
	/*
	* Invalidate D cache in case shared data was changed by
	* other processors to ensure cache coherence.
	*/
	resync_core_dcache();
	#endif
	}
	}

	int smp_call_function(void (func)(void info), void *info, int wait)
	{
	cpumask_t callmap;

	preempt_disable();
	callmap = cpu_online_map;
	cpu_clear(smp_processor_id(), callmap);
	if (!cpus_empty(callmap))
	smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);

	preempt_enable();

	return 0;
	}
	EXPORT_SYMBOL_GPL(smp_call_function);

	int smp_call_function_single(int cpuid, void (func) (void info), void *info,
	int wait)
	{
	unsigned int cpu = cpuid;
	cpumask_t callmap;

	if (cpu_is_offline(cpu))
	return 0;
	cpus_clear(callmap);
	cpu_set(cpu, callmap);

	smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);

	return 0;
	}
	EXPORT_SYMBOL_GPL(smp_call_function_single);

	void smp_send_reschedule(int cpu)
	{
	/* simply trigger an ipi */
	if (cpu_is_offline(cpu))
	return;
	platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);

	return;
	}

	void smp_send_stop(void)
	{
	cpumask_t callmap;

	preempt_disable();
	callmap = cpu_online_map;
	cpu_clear(smp_processor_id(), callmap);
	if (!cpus_empty(callmap))
	smp_send_message(callmap, BFIN_IPI_CPU_STOP, NULL, NULL, 0);

	preempt_enable();

	return;
	}

	int __cpuinit __cpu_up(unsigned int cpu)
	{
	int ret;
	static struct task_struct *idle;

	if (idle)
	free_task(idle);

	idle = fork_idle(cpu);
	if (IS_ERR(idle)) {
	printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
	return PTR_ERR(idle);
	}

	secondary_stack = task_stack_page(idle) + THREAD_SIZE;

	ret = platform_boot_secondary(cpu, idle);

	secondary_stack = NULL;

	return ret;
	}

	static void __cpuinit setup_secondary(unsigned int cpu)
	{
	unsigned long ilat;

	bfin_write_IMASK(0);
	CSYNC();
	ilat = bfin_read_ILAT();
	CSYNC();
	bfin_write_ILAT(ilat);
	CSYNC();

	/* Enable interrupt levels IVG7-15. IARs have been already
	* programmed by the boot CPU. */
	bfin_irq_flags \|= IMASK_IVG15 \|
	IMASK_IVG14 \| IMASK_IVG13 \| IMASK_IVG12 \| IMASK_IVG11 \|
	IMASK_IVG10 \| IMASK_IVG9 \| IMASK_IVG8 \| IMASK_IVG7 \| IMASK_IVGHW;
	}

	void __cpuinit secondary_start_kernel(void)
	{
	unsigned int cpu = smp_processor_id();
	struct mm_struct *mm = &init_mm;

	if (_bfin_swrst & SWRST_DBL_FAULT_B) {
	printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
	#ifdef CONFIG_DEBUG_DOUBLEFAULT
	printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
	(int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
	printk(KERN_NOTICE " DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
	printk(KERN_NOTICE " ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
	#endif
	printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
	init_retx_coreb);
	}

	/*
	* We want the D-cache to be enabled early, in case the atomic
	* support code emulates cache coherence (see
	* __ARCH_SYNC_CORE_DCACHE).
	*/
	init_exception_vectors();

	local_irq_disable();

	/* Attach the new idle task to the global mm. */
	atomic_inc(&mm->mm_users);
	atomic_inc(&mm->mm_count);
	current->active_mm = mm;

	preempt_disable();

	setup_secondary(cpu);

	platform_secondary_init(cpu);

	/* setup local core timer */
	bfin_local_timer_setup();

	local_irq_enable();

	bfin_setup_caches(cpu);

	/*
	* Calibrate loops per jiffy value.
	* IRQs need to be enabled here - D-cache can be invalidated
	* in timer irq handler, so core B can read correct jiffies.
	*/
	calibrate_delay();

	cpu_idle();
	}

	void __init smp_prepare_boot_cpu(void)
	{
	}

	void __init smp_prepare_cpus(unsigned int max_cpus)
	{
	platform_prepare_cpus(max_cpus);
	ipi_queue_init();
	platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0);
	platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1);
	}

	void __init smp_cpus_done(unsigned int max_cpus)
	{
	unsigned long bogosum = 0;
	unsigned int cpu;

	for_each_online_cpu(cpu)
	bogosum += loops_per_jiffy;

	printk(KERN_INFO "SMP: Total of %d processors activated "
	"(%lu.%02lu BogoMIPS).\n",
	num_online_cpus(),
	bogosum / (500000/HZ),
	(bogosum / (5000/HZ)) % 100);
	}

	void smp_icache_flush_range_others(unsigned long start, unsigned long end)
	{
	smp_flush_data.start = start;
	smp_flush_data.end = end;

	if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
	printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
	}
	EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);

	#ifdef __ARCH_SYNC_CORE_ICACHE
	unsigned long icache_invld_count[NR_CPUS];
	void resync_core_icache(void)
	{
	unsigned int cpu = get_cpu();
	blackfin_invalidate_entire_icache();
	icache_invld_count[cpu]++;
	put_cpu();
	}
	EXPORT_SYMBOL(resync_core_icache);
	#endif

	#ifdef __ARCH_SYNC_CORE_DCACHE
	unsigned long dcache_invld_count[NR_CPUS];
	unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));

	void resync_core_dcache(void)
	{
	unsigned int cpu = get_cpu();
	blackfin_invalidate_entire_dcache();
	dcache_invld_count[cpu]++;
	put_cpu();
	}
	EXPORT_SYMBOL(resync_core_dcache);
	#endif

	#ifdef CONFIG_HOTPLUG_CPU
	int __cpuexit __cpu_disable(void)
	{
	unsigned int cpu = smp_processor_id();

	if (cpu == 0)
	return -EPERM;

	set_cpu_online(cpu, false);
	return 0;
	}

	static DECLARE_COMPLETION(cpu_killed);

	int __cpuexit __cpu_die(unsigned int cpu)
	{
	return wait_for_completion_timeout(&cpu_killed, 5000);
	}

	void cpu_die(void)
	{
	complete(&cpu_killed);

	atomic_dec(&init_mm.mm_users);
	atomic_dec(&init_mm.mm_count);

	local_irq_disable();
	platform_cpu_die();
	}
	#endif