Blackfin: fix deadlock in SMP IPI handler

[firefly-linux-kernel-4.4.55.git] / arch / blackfin / mach-common / smp.c

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index c187da2448bfba74e68fb178e16ba029d98b12b9..61840059dfac30feb314fcf373f4ef51dea943cd 100644 (file)
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -144,7 +144,7 @@ static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
 
 static irqreturn_t ipi_handler(int irq, void *dev_instance)
 {
-       struct ipi_message *msg, *mg;
+       struct ipi_message *msg;
        struct ipi_message_queue *msg_queue;
        unsigned int cpu = smp_processor_id();
 
@@ -154,7 +154,8 @@ static irqreturn_t ipi_handler(int irq, void *dev_instance)
        msg_queue->count++;
 
        spin_lock(&msg_queue->lock);
-       list_for_each_entry_safe(msg, mg, &msg_queue->head, list) {
+       while (!list_empty(&msg_queue->head)) {
+               msg = list_entry(msg_queue->head.next, typeof(*msg), list);
                list_del(&msg->list);
                switch (msg->type) {
                case BFIN_IPI_RESCHEDULE:
@@ -221,7 +222,7 @@ int smp_call_function(void (*func)(void *info), void *info, int wait)
        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);
+               list_add_tail(&msg->list, &msg_queue->head);
                spin_unlock_irqrestore(&msg_queue->lock, flags);
                platform_send_ipi_cpu(cpu);
        }
@@ -261,7 +262,7 @@ int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 
        msg_queue = &per_cpu(ipi_msg_queue, cpu);
        spin_lock_irqsave(&msg_queue->lock, flags);
-       list_add(&msg->list, &msg_queue->head);
+       list_add_tail(&msg->list, &msg_queue->head);
        spin_unlock_irqrestore(&msg_queue->lock, flags);
        platform_send_ipi_cpu(cpu);
 
@@ -292,7 +293,7 @@ void smp_send_reschedule(int cpu)
 
        msg_queue = &per_cpu(ipi_msg_queue, cpu);
        spin_lock_irqsave(&msg_queue->lock, flags);
-       list_add(&msg->list, &msg_queue->head);
+       list_add_tail(&msg->list, &msg_queue->head);
        spin_unlock_irqrestore(&msg_queue->lock, flags);
        platform_send_ipi_cpu(cpu);
 
@@ -320,7 +321,7 @@ void smp_send_stop(void)
        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);
+               list_add_tail(&msg->list, &msg_queue->head);
                spin_unlock_irqrestore(&msg_queue->lock, flags);
                platform_send_ipi_cpu(cpu);
        }