arch/blackfin/mach-common/smp.c - maze/linux - Git at Google

 /*
  * File:         arch/blackfin/kernel/smp.c
  * Author:       Philippe Gerum <rpm@xenomai.org>
  * IPI management based on arch/arm/kernel/smp.c.
  *
  *               Copyright 2007 Analog Devices Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see the file COPYING, or write
  * to the Free Software Foundation, Inc.,
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #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/seq_file.h>
 #include <linux/irq.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 <linux/err.h>

 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));

 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;

 cpumask_t cpu_possible_map;
 EXPORT_SYMBOL(cpu_possible_map);

 cpumask_t cpu_online_map;
 EXPORT_SYMBOL(cpu_online_map);

 #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 pending;
 	cpumask_t waitmask;
 };

 static struct blackfin_flush_data smp_flush_data;

 static DEFINE_SPINLOCK(stop_lock);

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

 struct ipi_message_queue {
 	struct list_head head;
 	spinlock_t lock;
 	unsigned long count;
 };

 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. */
 	blackfin_dcache_invalidate_range((unsigned long)fdata,
 					 (unsigned long)fdata + sizeof(*fdata));

 	blackfin_icache_flush_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;
 	cpu_clear(cpu, msg->call_struct.pending);
 	func(info);
 	if (wait)
 		cpu_clear(cpu, msg->call_struct.waitmask);
 	else
 		kfree(msg);
 }

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

 	platform_clear_ipi(cpu);

 	msg_queue = &__get_cpu_var(ipi_msg_queue);
 	msg_queue->count++;

 	spin_lock(&msg_queue->lock);
 	list_for_each_entry_safe(msg, mg, &msg_queue->head, list) {
 		list_del(&msg->list);
 		switch (msg->type) {
 		case BFIN_IPI_RESCHEDULE:
 			/* That's the easiest one; leave it to
 			 * return_from_int. */
 			kfree(msg);
 			break;
 		case BFIN_IPI_CALL_FUNC:
 			spin_unlock(&msg_queue->lock);
 			ipi_call_function(cpu, msg);
 			spin_lock(&msg_queue->lock);
 			break;
 		case BFIN_IPI_CPU_STOP:
 			spin_unlock(&msg_queue->lock);
 			ipi_cpu_stop(cpu);
 			spin_lock(&msg_queue->lock);
 			kfree(msg);
 			break;
 		default:
 			printk(KERN_CRIT "CPU%u: Unknown IPI message \
 			0x%lx\n", cpu, msg->type);
 			kfree(msg);
 			break;
 		}
 	}
 	spin_unlock(&msg_queue->lock);
 	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);
 		INIT_LIST_HEAD(&msg_queue->head);
 		spin_lock_init(&msg_queue->lock);
 		msg_queue->count = 0;
 	}
 }

 int smp_call_function(void (*func)(void *info), void *info, int wait)
 {
 	unsigned int cpu;
 	cpumask_t callmap;
 	unsigned long flags;
 	struct ipi_message_queue *msg_queue;
 	struct ipi_message *msg;

 	callmap = cpu_online_map;
 	cpu_clear(smp_processor_id(), callmap);
 	if (cpus_empty(callmap))
 		return 0;

 	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 	INIT_LIST_HEAD(&msg->list);
 	msg->call_struct.func = func;
 	msg->call_struct.info = info;
 	msg->call_struct.wait = wait;
 	msg->call_struct.pending = callmap;
 	msg->call_struct.waitmask = callmap;
 	msg->type = BFIN_IPI_CALL_FUNC;

 	for_each_cpu_mask(cpu, callmap) {
 		msg_queue = &per_cpu(ipi_msg_queue, cpu);
 		spin_lock_irqsave(&msg_queue->lock, flags);
 		list_add(&msg->list, &msg_queue->head);
 		spin_unlock_irqrestore(&msg_queue->lock, flags);
 		platform_send_ipi_cpu(cpu);
 	}
 	if (wait) {
 		while (!cpus_empty(msg->call_struct.waitmask))
 			blackfin_dcache_invalidate_range(
 				(unsigned long)(&msg->call_struct.waitmask),
 				(unsigned long)(&msg->call_struct.waitmask));
 		kfree(msg);
 	}
 	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;
 	unsigned long flags;
 	struct ipi_message_queue *msg_queue;
 	struct ipi_message *msg;

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

 	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 	INIT_LIST_HEAD(&msg->list);
 	msg->call_struct.func = func;
 	msg->call_struct.info = info;
 	msg->call_struct.wait = wait;
 	msg->call_struct.pending = callmap;
 	msg->call_struct.waitmask = callmap;
 	msg->type = BFIN_IPI_CALL_FUNC;

 	msg_queue = &per_cpu(ipi_msg_queue, cpu);
 	spin_lock_irqsave(&msg_queue->lock, flags);
 	list_add(&msg->list, &msg_queue->head);
 	spin_unlock_irqrestore(&msg_queue->lock, flags);
 	platform_send_ipi_cpu(cpu);

 	if (wait) {
 		while (!cpus_empty(msg->call_struct.waitmask))
 			blackfin_dcache_invalidate_range(
 				(unsigned long)(&msg->call_struct.waitmask),
 				(unsigned long)(&msg->call_struct.waitmask));
 		kfree(msg);
 	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(smp_call_function_single);

 void smp_send_reschedule(int cpu)
 {
 	unsigned long flags;
 	struct ipi_message_queue *msg_queue;
 	struct ipi_message *msg;

 	if (cpu_is_offline(cpu))
 		return;

 	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 	memset(msg, 0, sizeof(msg));
 	INIT_LIST_HEAD(&msg->list);
 	msg->type = BFIN_IPI_RESCHEDULE;

 	msg_queue = &per_cpu(ipi_msg_queue, cpu);
 	spin_lock_irqsave(&msg_queue->lock, flags);
 	list_add(&msg->list, &msg_queue->head);
 	spin_unlock_irqrestore(&msg_queue->lock, flags);
 	platform_send_ipi_cpu(cpu);

 	return;
 }

 void smp_send_stop(void)
 {
 	unsigned int cpu;
 	cpumask_t callmap;
 	unsigned long flags;
 	struct ipi_message_queue *msg_queue;
 	struct ipi_message *msg;

 	callmap = cpu_online_map;
 	cpu_clear(smp_processor_id(), callmap);
 	if (cpus_empty(callmap))
 		return;

 	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 	memset(msg, 0, sizeof(msg));
 	INIT_LIST_HEAD(&msg->list);
 	msg->type = BFIN_IPI_CPU_STOP;

 	for_each_cpu_mask(cpu, callmap) {
 		msg_queue = &per_cpu(ipi_msg_queue, cpu);
 		spin_lock_irqsave(&msg_queue->lock, flags);
 		list_add(&msg->list, &msg_queue->head);
 		spin_unlock_irqrestore(&msg_queue->lock, flags);
 		platform_send_ipi_cpu(cpu);
 	}
 	return;
 }

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

 	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;
 	smp_wmb();

 	ret = platform_boot_secondary(cpu, idle);

 	if (ret) {
 		cpu_clear(cpu, cpu_present_map);
 		printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
 		free_task(idle);
 	} else
 		cpu_set(cpu, cpu_online_map);

 	secondary_stack = NULL;

 	return ret;
 }

 static void __cpuinit setup_secondary(unsigned int cpu)
 {
 #if !(defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE))
 	struct irq_desc *timer_desc;
 #endif
 	unsigned long ilat;

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

 	/* Reserve the PDA space for the secondary CPU. */
 	reserve_pda();

 	/* 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;

 #if defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE)
 	/* Power down the core timer, just to play safe. */
 	bfin_write_TCNTL(0);

 	/* system timer0 has been setup by CoreA. */
 #else
 	timer_desc = irq_desc + IRQ_CORETMR;
 	setup_core_timer();
 	timer_desc->chip->enable(IRQ_CORETMR);
 #endif
 }

 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();

 	bfin_setup_caches(cpu);

 	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;
 	BUG_ON(current->mm);	/* Can't be, but better be safe than sorry. */

 	preempt_disable();

 	setup_secondary(cpu);

 	local_irq_enable();

 	platform_secondary_init(cpu);

 	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(&ipi_handler);
 }

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

 	for_each_online_cpu(cpu)
 		bogosum += per_cpu(cpu_data, cpu).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_DCACHE
 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));

 void resync_core_dcache(void)
 {
 	unsigned int cpu = get_cpu();
 	blackfin_invalidate_entire_dcache();
 	++per_cpu(cpu_data, cpu).dcache_invld_count;
 	put_cpu();
 }
 EXPORT_SYMBOL(resync_core_dcache);
 #endif
	/*
	* File: arch/blackfin/kernel/smp.c
	* Author: Philippe Gerum <rpm@xenomai.org>
	* IPI management based on arch/arm/kernel/smp.c.
	*
	* Copyright 2007 Analog Devices Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see the file COPYING, or write
	* to the Free Software Foundation, Inc.,
	* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#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/seq_file.h>
	#include <linux/irq.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 <linux/err.h>

	struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));

	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;

	cpumask_t cpu_possible_map;
	EXPORT_SYMBOL(cpu_possible_map);

	cpumask_t cpu_online_map;
	EXPORT_SYMBOL(cpu_online_map);

	#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 pending;
	cpumask_t waitmask;
	};

	static struct blackfin_flush_data smp_flush_data;

	static DEFINE_SPINLOCK(stop_lock);

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

	struct ipi_message_queue {
	struct list_head head;
	spinlock_t lock;
	unsigned long count;
	};

	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. */
	blackfin_dcache_invalidate_range((unsigned long)fdata,
	(unsigned long)fdata + sizeof(*fdata));

	blackfin_icache_flush_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;
	cpu_clear(cpu, msg->call_struct.pending);
	func(info);
	if (wait)
	cpu_clear(cpu, msg->call_struct.waitmask);
	else
	kfree(msg);
	}

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

	platform_clear_ipi(cpu);

	msg_queue = &__get_cpu_var(ipi_msg_queue);
	msg_queue->count++;

	spin_lock(&msg_queue->lock);
	list_for_each_entry_safe(msg, mg, &msg_queue->head, list) {
	list_del(&msg->list);
	switch (msg->type) {
	case BFIN_IPI_RESCHEDULE:
	/* That's the easiest one; leave it to
	* return_from_int. */
	kfree(msg);
	break;
	case BFIN_IPI_CALL_FUNC:
	spin_unlock(&msg_queue->lock);
	ipi_call_function(cpu, msg);
	spin_lock(&msg_queue->lock);
	break;
	case BFIN_IPI_CPU_STOP:
	spin_unlock(&msg_queue->lock);
	ipi_cpu_stop(cpu);
	spin_lock(&msg_queue->lock);
	kfree(msg);
	break;
	default:
	printk(KERN_CRIT "CPU%u: Unknown IPI message \
	0x%lx\n", cpu, msg->type);
	kfree(msg);
	break;
	}
	}
	spin_unlock(&msg_queue->lock);
	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);
	INIT_LIST_HEAD(&msg_queue->head);
	spin_lock_init(&msg_queue->lock);
	msg_queue->count = 0;
	}
	}

	int smp_call_function(void (func)(void info), void *info, int wait)
	{
	unsigned int cpu;
	cpumask_t callmap;
	unsigned long flags;
	struct ipi_message_queue *msg_queue;
	struct ipi_message *msg;

	callmap = cpu_online_map;
	cpu_clear(smp_processor_id(), callmap);
	if (cpus_empty(callmap))
	return 0;

	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
	INIT_LIST_HEAD(&msg->list);
	msg->call_struct.func = func;
	msg->call_struct.info = info;
	msg->call_struct.wait = wait;
	msg->call_struct.pending = callmap;
	msg->call_struct.waitmask = callmap;
	msg->type = BFIN_IPI_CALL_FUNC;

	for_each_cpu_mask(cpu, callmap) {
	msg_queue = &per_cpu(ipi_msg_queue, cpu);
	spin_lock_irqsave(&msg_queue->lock, flags);
	list_add(&msg->list, &msg_queue->head);
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	platform_send_ipi_cpu(cpu);
	}
	if (wait) {
	while (!cpus_empty(msg->call_struct.waitmask))
	blackfin_dcache_invalidate_range(
	(unsigned long)(&msg->call_struct.waitmask),
	(unsigned long)(&msg->call_struct.waitmask));
	kfree(msg);
	}
	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;
	unsigned long flags;
	struct ipi_message_queue *msg_queue;
	struct ipi_message *msg;

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

	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
	INIT_LIST_HEAD(&msg->list);
	msg->call_struct.func = func;
	msg->call_struct.info = info;
	msg->call_struct.wait = wait;
	msg->call_struct.pending = callmap;
	msg->call_struct.waitmask = callmap;
	msg->type = BFIN_IPI_CALL_FUNC;

	msg_queue = &per_cpu(ipi_msg_queue, cpu);
	spin_lock_irqsave(&msg_queue->lock, flags);
	list_add(&msg->list, &msg_queue->head);
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	platform_send_ipi_cpu(cpu);

	if (wait) {
	while (!cpus_empty(msg->call_struct.waitmask))
	blackfin_dcache_invalidate_range(
	(unsigned long)(&msg->call_struct.waitmask),
	(unsigned long)(&msg->call_struct.waitmask));
	kfree(msg);
	}
	return 0;
	}
	EXPORT_SYMBOL_GPL(smp_call_function_single);

	void smp_send_reschedule(int cpu)
	{
	unsigned long flags;
	struct ipi_message_queue *msg_queue;
	struct ipi_message *msg;

	if (cpu_is_offline(cpu))
	return;

	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
	memset(msg, 0, sizeof(msg));
	INIT_LIST_HEAD(&msg->list);
	msg->type = BFIN_IPI_RESCHEDULE;

	msg_queue = &per_cpu(ipi_msg_queue, cpu);
	spin_lock_irqsave(&msg_queue->lock, flags);
	list_add(&msg->list, &msg_queue->head);
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	platform_send_ipi_cpu(cpu);

	return;
	}

	void smp_send_stop(void)
	{
	unsigned int cpu;
	cpumask_t callmap;
	unsigned long flags;
	struct ipi_message_queue *msg_queue;
	struct ipi_message *msg;

	callmap = cpu_online_map;
	cpu_clear(smp_processor_id(), callmap);
	if (cpus_empty(callmap))
	return;

	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
	memset(msg, 0, sizeof(msg));
	INIT_LIST_HEAD(&msg->list);
	msg->type = BFIN_IPI_CPU_STOP;

	for_each_cpu_mask(cpu, callmap) {
	msg_queue = &per_cpu(ipi_msg_queue, cpu);
	spin_lock_irqsave(&msg_queue->lock, flags);
	list_add(&msg->list, &msg_queue->head);
	spin_unlock_irqrestore(&msg_queue->lock, flags);
	platform_send_ipi_cpu(cpu);
	}
	return;
	}

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

	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;
	smp_wmb();

	ret = platform_boot_secondary(cpu, idle);

	if (ret) {
	cpu_clear(cpu, cpu_present_map);
	printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
	free_task(idle);
	} else
	cpu_set(cpu, cpu_online_map);

	secondary_stack = NULL;

	return ret;
	}

	static void __cpuinit setup_secondary(unsigned int cpu)
	{
	#if !(defined(CONFIG_TICK_SOURCE_SYSTMR0) \|\| defined(CONFIG_IPIPE))
	struct irq_desc *timer_desc;
	#endif
	unsigned long ilat;

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

	/* Reserve the PDA space for the secondary CPU. */
	reserve_pda();

	/* 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;

	#if defined(CONFIG_TICK_SOURCE_SYSTMR0) \|\| defined(CONFIG_IPIPE)
	/* Power down the core timer, just to play safe. */
	bfin_write_TCNTL(0);

	/* system timer0 has been setup by CoreA. */
	#else
	timer_desc = irq_desc + IRQ_CORETMR;
	setup_core_timer();
	timer_desc->chip->enable(IRQ_CORETMR);
	#endif
	}

	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();

	bfin_setup_caches(cpu);

	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;
	BUG_ON(current->mm); /* Can't be, but better be safe than sorry. */

	preempt_disable();

	setup_secondary(cpu);

	local_irq_enable();

	platform_secondary_init(cpu);

	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(&ipi_handler);
	}

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

	for_each_online_cpu(cpu)
	bogosum += per_cpu(cpu_data, cpu).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_DCACHE
	unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));

	void resync_core_dcache(void)
	{
	unsigned int cpu = get_cpu();
	blackfin_invalidate_entire_dcache();
	++per_cpu(cpu_data, cpu).dcache_invld_count;
	put_cpu();
	}
	EXPORT_SYMBOL(resync_core_dcache);
	#endif