blackfin: smp: adapt to generic smp helpers

Replace blackfin ipi message queue with generic smp helper function.
Signed-off-by: Steven Miao <realmz6@gmail.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>

arch/blackfin/Kconfig

@@ -38,6 +38,7 @@ config BLACKFIN
 	select GENERIC_ATOMIC64
 	select GENERIC_IRQ_PROBE
 	select IRQ_PER_CPU if SMP
+	select USE_GENERIC_SMP_HELPERS if SMP
 	select HAVE_NMI_WATCHDOG if NMI_WATCHDOG
 	select GENERIC_SMP_IDLE_THREAD
 	select ARCH_USES_GETTIMEOFFSET if !GENERIC_CLOCKEVENTS

arch/blackfin/include/asm/smp.h

@@ -18,6 +18,8 @@
 #define raw_smp_processor_id()  blackfin_core_id()
 
 extern void bfin_relocate_coreb_l1_mem(void);
+extern void arch_send_call_function_single_ipi(int cpu);
+extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
 #if defined(CONFIG_SMP) && defined(CONFIG_ICACHE_FLUSH_L1)
 asmlinkage void blackfin_icache_flush_range_l1(unsigned long *ptr);

arch/blackfin/mach-common/smp.c

@@ -48,10 +48,13 @@ unsigned long blackfin_iflush_l1_entry[NR_CPUS];
 
 struct blackfin_initial_pda __cpuinitdata initial_pda_coreb;
 
-#define BFIN_IPI_TIMER	      0
-#define BFIN_IPI_RESCHEDULE   1
-#define BFIN_IPI_CALL_FUNC    2
-#define BFIN_IPI_CPU_STOP     3
+enum ipi_message_type {
+	BFIN_IPI_TIMER,
+	BFIN_IPI_RESCHEDULE,
+	BFIN_IPI_CALL_FUNC,
+	BFIN_IPI_CALL_FUNC_SINGLE,
+	BFIN_IPI_CPU_STOP,
+};
 
 struct blackfin_flush_data {
 	unsigned long start;
@@ -60,35 +63,20 @@ struct blackfin_flush_data {
 
 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;
+struct ipi_data {
 	unsigned long count;
-	unsigned long head; /* head of the queue */
-	struct ipi_message ipi_message[BFIN_IPI_MSGQ_LEN];
+	unsigned long 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)
 {
@@ -129,28 +117,6 @@ static void ipi_flush_icache(void *info)
 	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;
-	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
-		cpumask_clear_cpu(cpu, msg->call_struct.waitmask);
-	}
-}
-
 /* Use IRQ_SUPPLE_0 to request reschedule.
  * When returning from interrupt to user space,
  * there is chance to reschedule */
@@ -172,20 +138,20 @@ void ipi_timer(void)
 
 static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
 {
-	struct ipi_message *msg;
-	struct ipi_message_queue *msg_queue;
+	struct ipi_data *bfin_ipi_data;
 	unsigned int cpu = smp_processor_id();
-	unsigned long flags;
+	unsigned long pending;
+	unsigned long msg;
 
 	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
 
-	msg_queue = &__get_cpu_var(ipi_msg_queue);
-
-	spin_lock_irqsave(&msg_queue->lock, flags);
+	bfin_ipi_data = &__get_cpu_var(bfin_ipi);
 
-	while (msg_queue->count) {
-		msg = &msg_queue->ipi_message[msg_queue->head];
-		switch (msg->type) {
+	while ((pending = 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;
@@ -193,131 +159,74 @@ static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
 				scheduler_ipi();
 				break;
 			case BFIN_IPI_CALL_FUNC:
-			ipi_call_function(cpu, msg);
+				generic_smp_call_function_interrupt();
 				break;
+
+			case BFIN_IPI_CALL_FUNC_SINGLE:
+				generic_smp_call_function_single_interrupt();
+				break;
+
 			case BFIN_IPI_CPU_STOP:
 				ipi_cpu_stop(cpu);
 				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--;
+		} while (msg < BITS_PER_LONG);
+
+		smp_mb();
 	}
-	spin_unlock_irqrestore(&msg_queue->lock, flags);
 	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);
-		spin_lock_init(&msg_queue->lock);
-		msg_queue->count = 0;
-		msg_queue->head = 0;
+		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
+		bfin_ipi_data->bits = 0;
+		bfin_ipi_data->count = 0;
 	}
 }
 
-static inline void smp_send_message(cpumask_t callmap, unsigned long type,
-					void (*func) (void *info), void *info, int wait)
+void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
 {
 	unsigned int cpu;
-	struct ipi_message_queue *msg_queue;
-	struct ipi_message *msg;
-	unsigned long flags, next_msg;
-	cpumask_t waitmask; /* waitmask is shared by all cpus */
-
-	cpumask_copy(&waitmask, &callmap);
-	for_each_cpu(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);
+	struct ipi_data *bfin_ipi_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	for_each_cpu(cpu, cpumask) {
+		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
+		smp_mb();
+		set_bit(msg, &bfin_ipi_data->bits);
+		bfin_ipi_data->count++;
 		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
 	}
 
-	if (wait) {
-		while (!cpumask_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
-	}
+	local_irq_restore(flags);
 }
 
-int smp_call_function(void (*func)(void *info), void *info, int wait)
+void arch_send_call_function_single_ipi(int cpu)
 {
-	cpumask_t callmap;
-
-	preempt_disable();
-	cpumask_copy(&callmap, cpu_online_mask);
-	cpumask_clear_cpu(smp_processor_id(), &callmap);
-	if (!cpumask_empty(&callmap))
-		smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
-
-	preempt_enable();
-
-	return 0;
+	send_ipi(cpumask_of(cpu), BFIN_IPI_CALL_FUNC_SINGLE);
 }
-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_ipi_mask(const struct cpumask *mask)
 {
-	unsigned int cpu = cpuid;
-	cpumask_t callmap;
-
-	if (cpu_is_offline(cpu))
-		return 0;
-	cpumask_clear(&callmap);
-	cpumask_set_cpu(cpu, &callmap);
-
-	smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
-
-	return 0;
+	send_ipi(mask, BFIN_IPI_CALL_FUNC);
 }
-EXPORT_SYMBOL_GPL(smp_call_function_single);
 
 void smp_send_reschedule(int cpu)
 {
-	cpumask_t callmap;
-	/* simply trigger an ipi */
-
-	cpumask_clear(&callmap);
-	cpumask_set_cpu(cpu, &callmap);
-
-	smp_send_message(callmap, BFIN_IPI_RESCHEDULE, NULL, NULL, 0);
+	send_ipi(cpumask_of(cpu), BFIN_IPI_RESCHEDULE);
 
 	return;
 }
 
 void smp_send_msg(const struct cpumask *mask, unsigned long type)
 {
-	smp_send_message(*mask, type, NULL, NULL, 0);
+	send_ipi(mask, type);
 }
 
 void smp_timer_broadcast(const struct cpumask *mask)
@@ -333,7 +242,7 @@ void smp_send_stop(void)
 	cpumask_copy(&callmap, cpu_online_mask);
 	cpumask_clear_cpu(smp_processor_id(), &callmap);
 	if (!cpumask_empty(&callmap))
-		smp_send_message(callmap, BFIN_IPI_CPU_STOP, NULL, NULL, 0);
+		send_ipi(&callmap, BFIN_IPI_CPU_STOP);
 
 	preempt_enable();
 
@@ -436,7 +345,7 @@ void __init smp_prepare_boot_cpu(void)
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
 	platform_prepare_cpus(max_cpus);
-	ipi_queue_init();
+	bfin_ipi_init();
 	platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0);
 	platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1);
 }