1 files changed, 216 insertions, 263 deletions

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index 93eab614607..ba6c30d8534 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -1,24 +1,10 @@
 /*
- * File:         arch/blackfin/kernel/smp.c
- * Author:       Philippe Gerum <rpm@xenomai.org>
- * IPI management based on arch/arm/kernel/smp.c.
+ * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
  *
- *               Copyright 2007 Analog Devices Inc.
+ * Copyright 2007-2009 Analog Devices Inc.
+ *                         Philippe Gerum <rpm@xenomai.org>
  *
- * 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
+ * Licensed under the GPL-2.
  */
 
 #include <linux/module.h>
@@ -28,38 +14,47 @@
 #include <linux/sched.h>
 #include <linux/interrupt.h>
 #include <linux/cache.h>
+#include <linux/clockchips.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 <asm/atomic.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
 #include <asm/cacheflush.h>
+#include <asm/irq_handler.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")));
 
-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);
+#ifdef CONFIG_ICACHE_FLUSH_L1
+unsigned long blackfin_iflush_l1_entry[NR_CPUS];
+#endif
 
-cpumask_t cpu_online_map;
-EXPORT_SYMBOL(cpu_online_map);
+struct blackfin_initial_pda initial_pda_coreb;
 
-#define BFIN_IPI_RESCHEDULE   0
-#define BFIN_IPI_CALL_FUNC    1
-#define BFIN_IPI_CPU_STOP     2
+enum ipi_message_type {
+	BFIN_IPI_NONE,
+	BFIN_IPI_TIMER,
+	BFIN_IPI_RESCHEDULE,
+	BFIN_IPI_CALL_FUNC,
+	BFIN_IPI_CPU_STOP,
+};
 
 struct blackfin_flush_data {
 	unsigned long start;
@@ -68,32 +63,20 @@ struct blackfin_flush_data {
 
 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;
-};
+/* A magic number - stress test shows this is safe for common cases */
+#define BFIN_IPI_MSGQ_LEN 5
 
-struct ipi_message_queue {
-	struct list_head head;
-	spinlock_t lock;
-	unsigned long count;
+/* Simple FIFO buffer, overflow leads to panic */
+struct ipi_data {
+	atomic_t count;
+	atomic_t bits;
 };
 
-static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
+static DEFINE_PER_CPU(struct ipi_data, bfin_ipi);
 
 static void ipi_cpu_stop(unsigned int cpu)
 {
@@ -102,7 +85,7 @@ static void ipi_cpu_stop(unsigned int cpu)
 	dump_stack();
 	spin_unlock(&stop_lock);
 
-	cpu_clear(cpu, cpu_online_map);
+	set_cpu_online(cpu, false);
 
 	local_irq_disable();
 
@@ -118,243 +101,166 @@ static void ipi_flush_icache(void *info)
 	blackfin_dcache_invalidate_range((unsigned long)fdata,
 					 (unsigned long)fdata + sizeof(*fdata));
 
+	/* Make sure all write buffers in the data side of the core
+	 * are flushed before trying to invalidate the icache.  This
+	 * needs to be after the data flush and before the icache
+	 * flush so that the SSYNC does the right thing in preventing
+	 * the instruction prefetcher from hitting things in cached
+	 * memory at the wrong time -- it runs much further ahead than
+	 * the pipeline.
+	 */
+	SSYNC();
+
+	/* ipi_flaush_icache is invoked by generic flush_icache_range,
+	 * so call blackfin arch icache flush directly here.
+	 */
 	blackfin_icache_flush_range(fdata->start, fdata->end);
 }
 
-static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
+/* 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)
 {
-	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);
+	unsigned int cpu = smp_processor_id();
+
+	platform_clear_ipi(cpu, IRQ_SUPPLE_0);
+	return IRQ_HANDLED;
 }
 
-static irqreturn_t ipi_handler(int irq, void *dev_instance)
+DECLARE_PER_CPU(struct clock_event_device, coretmr_events);
+void ipi_timer(void)
 {
-	struct ipi_message *msg, *mg;
-	struct ipi_message_queue *msg_queue;
+	int cpu = smp_processor_id();
+	struct clock_event_device *evt = &per_cpu(coretmr_events, cpu);
+	evt->event_handler(evt);
+}
+
+static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
+{
+	struct ipi_data *bfin_ipi_data;
 	unsigned int cpu = smp_processor_id();
+	unsigned long pending;
+	unsigned long msg;
+
+	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
+
+	smp_rmb();
+	bfin_ipi_data = &__get_cpu_var(bfin_ipi);
+	while ((pending = atomic_xchg(&bfin_ipi_data->bits, 0)) != 0) {
+		msg = 0;
+		do {
+			msg = find_next_bit(&pending, BITS_PER_LONG, msg + 1);
+			switch (msg) {
+			case BFIN_IPI_TIMER:
+				ipi_timer();
+				break;
+			case BFIN_IPI_RESCHEDULE:
+				scheduler_ipi();
+				break;
+			case BFIN_IPI_CALL_FUNC:
+				generic_smp_call_function_interrupt();
+				break;
+			case BFIN_IPI_CPU_STOP:
+				ipi_cpu_stop(cpu);
+				break;
+			default:
+				goto out;
+			}
+			atomic_dec(&bfin_ipi_data->count);
+		} while (msg < BITS_PER_LONG);
 
-	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);
+out:
 	return IRQ_HANDLED;
 }
 
-static void ipi_queue_init(void)
+static void bfin_ipi_init(void)
 {
 	unsigned int cpu;
-	struct ipi_message_queue *msg_queue;
+	struct ipi_data *bfin_ipi_data;
 	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;
+		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
+		atomic_set(&bfin_ipi_data->bits, 0);
+		atomic_set(&bfin_ipi_data->count, 0);
 	}
 }
 
-int smp_call_function(void (*func)(void *info), void *info, int wait)
+void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
 {
 	unsigned int cpu;
-	cpumask_t callmap;
+	struct ipi_data *bfin_ipi_data;
 	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);
+
+	local_irq_save(flags);
+	for_each_cpu(cpu, cpumask) {
+		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
+		atomic_set_mask((1 << msg), &bfin_ipi_data->bits);
+		atomic_inc(&bfin_ipi_data->count);
 	}
-	return 0;
+	local_irq_restore(flags);
+	smp_wmb();
+	for_each_cpu(cpu, cpumask)
+		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
 }
-EXPORT_SYMBOL_GPL(smp_call_function);
 
-int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
-				int wait)
+void arch_send_call_function_single_ipi(int cpu)
 {
-	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;
+	send_ipi(cpumask_of(cpu), BFIN_IPI_CALL_FUNC);
 }
-EXPORT_SYMBOL_GPL(smp_call_function_single);
 
-void smp_send_reschedule(int cpu)
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 {
-	unsigned long flags;
-	struct ipi_message_queue *msg_queue;
-	struct ipi_message *msg;
+	send_ipi(mask, BFIN_IPI_CALL_FUNC);
+}
 
-	if (cpu_is_offline(cpu))
-		return;
+void smp_send_reschedule(int cpu)
+{
+	send_ipi(cpumask_of(cpu), BFIN_IPI_RESCHEDULE);
 
-	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
-	memset(msg, 0, sizeof(msg));
-	INIT_LIST_HEAD(&msg->list);
-	msg->type = BFIN_IPI_RESCHEDULE;
+	return;
+}
 
-	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);
+void smp_send_msg(const struct cpumask *mask, unsigned long type)
+{
+	send_ipi(mask, type);
+}
 
-	return;
+void smp_timer_broadcast(const struct cpumask *mask)
+{
+	smp_send_msg(mask, BFIN_IPI_TIMER);
 }
 
 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);
-	}
+
+	preempt_disable();
+	cpumask_copy(&callmap, cpu_online_mask);
+	cpumask_clear_cpu(smp_processor_id(), &callmap);
+	if (!cpumask_empty(&callmap))
+		send_ipi(&callmap, BFIN_IPI_CPU_STOP);
+
+	preempt_enable();
+
 	return;
 }
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
-	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)
+static void 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);
@@ -364,28 +270,14 @@ static void __cpuinit setup_secondary(unsigned int cpu)
 	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)
+void secondary_start_kernel(void)
 {
 	unsigned int cpu = smp_processor_id();
 	struct mm_struct *mm = &init_mm;
@@ -393,13 +285,16 @@ void __cpuinit secondary_start_kernel(void)
 	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);
+		printk(KERN_EMERG " While handling exception (EXCAUSE = %#x) at %pF\n",
+			initial_pda_coreb.seqstat_doublefault & SEQSTAT_EXCAUSE,
+			initial_pda_coreb.retx_doublefault);
+		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n",
+			initial_pda_coreb.dcplb_doublefault_addr);
+		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n",
+			initial_pda_coreb.icplb_doublefault_addr);
 #endif
 		printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
-			init_retx_coreb);
+			initial_pda_coreb.retx);
 	}
 
 	/*
@@ -409,25 +304,36 @@ void __cpuinit secondary_start_kernel(void)
 	 */
 	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);
 
+	platform_secondary_init(cpu);
+	/* setup local core timer */
+	bfin_local_timer_setup();
+
 	local_irq_enable();
 
-	platform_secondary_init(cpu);
+	bfin_setup_caches(cpu);
 
-	cpu_idle();
+	notify_cpu_starting(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();
+
+	/* We are done with local CPU inits, unblock the boot CPU. */
+	set_cpu_online(cpu, true);
+	cpu_startup_entry(CPUHP_ONLINE);
 }
 
 void __init smp_prepare_boot_cpu(void)
@@ -437,8 +343,9 @@ 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);
+	bfin_ipi_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)
@@ -447,7 +354,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 	unsigned int cpu;
 
 	for_each_online_cpu(cpu)
-		bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
+		bogosum += loops_per_jiffy;
 
 	printk(KERN_INFO "SMP: Total of %d processors activated "
 	       "(%lu.%02lu BogoMIPS).\n",
@@ -461,20 +368,66 @@ 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))
+	preempt_disable();
+	if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 1))
 		printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
+	preempt_enable();
 }
 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();
-	++per_cpu(cpu_data, cpu).dcache_invld_count;
+	dcache_invld_count[cpu]++;
 	put_cpu();
 }
 EXPORT_SYMBOL(resync_core_dcache);
 #endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+int __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 __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