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Diffstat (limited to 'arch/blackfin/mach-common/smp.c')
-rw-r--r--arch/blackfin/mach-common/smp.c197
1 files changed, 78 insertions, 119 deletions
diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index 930608dd358d..9f251406a76a 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -60,8 +60,7 @@ struct smp_call_struct {
void (*func)(void *info);
void *info;
int wait;
- cpumask_t pending;
- cpumask_t waitmask;
+ cpumask_t *waitmask;
};
static struct blackfin_flush_data smp_flush_data;
@@ -69,15 +68,19 @@ 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
+
+/* Simple FIFO buffer, overflow leads to panic */
struct ipi_message_queue {
- struct list_head head;
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);
@@ -116,7 +119,6 @@ static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
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) {
#ifdef __ARCH_SYNC_CORE_DCACHE
@@ -127,51 +129,57 @@ static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
*/
resync_core_dcache();
#endif
- cpu_clear(cpu, msg->call_struct.waitmask);
- } else
- kfree(msg);
+ cpu_clear(cpu, *msg->call_struct.waitmask);
+ }
}
-static irqreturn_t ipi_handler(int irq, void *dev_instance)
+/* 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);
+ platform_clear_ipi(cpu, IRQ_SUPPLE_1);
msg_queue = &__get_cpu_var(ipi_msg_queue);
- msg_queue->count++;
- spin_lock(&msg_queue->lock);
- while (!list_empty(&msg_queue->head)) {
- msg = list_entry(msg_queue->head.next, typeof(*msg), list);
- list_del(&msg->list);
+ 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_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);
+ spin_unlock_irqrestore(&msg_queue->lock, flags);
ipi_call_function(cpu, msg);
- spin_lock(&msg_queue->lock);
+ spin_lock_irqsave(&msg_queue->lock, flags);
break;
case BFIN_IPI_CPU_STOP:
- spin_unlock(&msg_queue->lock);
+ spin_unlock_irqrestore(&msg_queue->lock, flags);
ipi_cpu_stop(cpu);
- spin_lock(&msg_queue->lock);
- kfree(msg);
+ spin_lock_irqsave(&msg_queue->lock, flags);
break;
default:
printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%lx\n",
cpu, msg->type);
- kfree(msg);
break;
}
+ msg_queue->head++;
+ msg_queue->head %= BFIN_IPI_MSGQ_LEN;
+ msg_queue->count--;
}
- spin_unlock(&msg_queue->lock);
+ spin_unlock_irqrestore(&msg_queue->lock, flags);
return IRQ_HANDLED;
}
@@ -181,48 +189,47 @@ static void ipi_queue_init(void)
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;
+ msg_queue->head = 0;
}
}
-int smp_call_function(void (*func)(void *info), void *info, int wait)
+static inline void smp_send_message(cpumask_t callmap, unsigned long type,
+ 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);
- if (!msg)
- return -ENOMEM;
- 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;
+ 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);
- list_add_tail(&msg->list, &msg_queue->head);
+ 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);
+ platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
}
+
if (wait) {
- while (!cpus_empty(msg->call_struct.waitmask))
+ while (!cpus_empty(waitmask))
blackfin_dcache_invalidate_range(
- (unsigned long)(&msg->call_struct.waitmask),
- (unsigned long)(&msg->call_struct.waitmask));
+ (unsigned long)(&waitmask),
+ (unsigned long)(&waitmask));
#ifdef __ARCH_SYNC_CORE_DCACHE
/*
* Invalidate D cache in case shared data was changed by
@@ -230,8 +237,20 @@ int smp_call_function(void (*func)(void *info), void *info, int wait)
*/
resync_core_dcache();
#endif
- kfree(msg);
}
+}
+
+int smp_call_function(void (*func)(void *info), void *info, int wait)
+{
+ cpumask_t callmap;
+
+ callmap = cpu_online_map;
+ cpu_clear(smp_processor_id(), callmap);
+ if (cpus_empty(callmap))
+ return 0;
+
+ smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
+
return 0;
}
EXPORT_SYMBOL_GPL(smp_call_function);
@@ -241,100 +260,39 @@ int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
{
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);
- if (!msg)
- return -ENOMEM;
- 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_tail(&msg->list, &msg_queue->head);
- spin_unlock_irqrestore(&msg_queue->lock, flags);
- platform_send_ipi_cpu(cpu);
+ smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
- 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));
-#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
- 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;
-
+ /* simply trigger an ipi */
if (cpu_is_offline(cpu))
return;
-
- msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
- if (!msg)
- return;
- 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_tail(&msg->list, &msg_queue->head);
- spin_unlock_irqrestore(&msg_queue->lock, flags);
- platform_send_ipi_cpu(cpu);
+ platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
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 = kzalloc(sizeof(*msg), GFP_ATOMIC);
- if (!msg)
- return;
- INIT_LIST_HEAD(&msg->list);
- msg->type = BFIN_IPI_CPU_STOP;
+ smp_send_message(callmap, BFIN_IPI_CPU_STOP, NULL, NULL, 0);
- for_each_cpu_mask(cpu, callmap) {
- msg_queue = &per_cpu(ipi_msg_queue, cpu);
- spin_lock_irqsave(&msg_queue->lock, flags);
- list_add_tail(&msg->list, &msg_queue->head);
- spin_unlock_irqrestore(&msg_queue->lock, flags);
- platform_send_ipi_cpu(cpu);
- }
return;
}
@@ -441,7 +399,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
{
platform_prepare_cpus(max_cpus);
ipi_queue_init();
- platform_request_ipi(ipi_handler);
+ 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)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 02:23:43 +0100