[PATCH 01/18] fence: add debugging lines to fence_is_signaled for the callback

Maarten Lankhorst
2014-07-31T15:31:09Z

fence_is_signaled callback should support being run in
atomic context, but not in irq context.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
---
include/linux/fence.h | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/include/linux/fence.h b/include/linux/fence.h
index d174585b874b..c1a4519ba2f5 100644
--- a/include/linux/fence.h
+++ b/include/linux/fence.h
@@ -143,6 +143,7 @@ struct fence_cb {
* the second time will be a noop since it was already signaled.
*
* Notes on signaled:
+ * Called with interrupts enabled, and never from interrupt context.
* May set fence->status if returning true.
*
* Notes on wait:
@@ -268,15 +269,29 @@ fence_is_signaled_locked(struct fence *fence)
static inline bool
fence_is_signaled(struct fence *fence)
{
+ bool ret;
+
if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags))
return true;

- if (fence->ops->signaled && fence->ops->signaled(fence)) {
+ if (!fence->ops->signaled)
+ return false;
+
+ if (config_enabled(CONFIG_PROVE_LOCKING))
+ WARN_ON(in_interrupt() || irqs_disabled());
+
+ if (config_enabled(CONFIG_DEBUG_ATOMIC_SLEEP))
+ preempt_disable();
+
+ ret = fence->ops->signaled(fence);
+
+ if (config_enabled(CONFIG_DEBUG_ATOMIC_SLEEP))
+ preempt_enable();
+
+ if (ret)
fence_signal(fence);
- return true;
- }

- return false;
+ return ret;
}

/**