aboutsummaryrefslogtreecommitdiff
path: root/arch/blackfin
diff options
context:
space:
mode:
authorSonic Zhang <sonic.zhang@analog.com>2009-06-10 08:42:41 +0000
committerMike Frysinger <vapier@gentoo.org>2009-06-13 07:20:09 -0400
commit86f2008bf546af9a434f480710e8d33891616bf5 (patch)
treee55bf8eec1f6dbbf3ba052c3a595f4806c724a6e /arch/blackfin
parentf9ee3ab81c222219ad4467b75b406efe2616d8a4 (diff)
downloadlinux-2.6.34-ux500-86f2008bf546af9a434f480710e8d33891616bf5.tar.gz
Blackfin: fix deadlock in SMP IPI handler
When a low priority interrupt (like ethernet) is triggered between 2 high priority IPI messages, a deadlock in disable_irq() is hit by the second IPI handler. This is because the second IPI message is queued within the first IPI handler, but the handler doesn't process all messages, and new ones are inserted rather than appended. So now we process all the pending messages, and append new ones to the pending list. URL: http://blackfin.uclinux.org/gf/tracker/5226 Signed-off-by: Sonic Zhang <sonic.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/mach-common/smp.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index c187da2448b..61840059dfa 100644
--- 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);
}