drm/radeon: rework fence handling, drop fence list v7
Using 64bits fence sequence we can directly compare sequence
number to know if a fence is signaled or not. Thus the fence
list became useless, so does the fence lock that mainly
protected the fence list.
Things like ring.ready are no longer behind a lock, this should
be ok as ring.ready is initialized once and will only change
when facing lockup. Worst case is that we return an -EBUSY just
after a successfull GPU reset, or we go into wait state instead
of returning -EBUSY (thus delaying reporting -EBUSY to fence
wait caller).
v2: Remove left over comment, force using writeback on cayman and
newer, thus not having to suffer from possibly scratch reg
exhaustion
v3: Rebase on top of change to uint64 fence patch
v4: Change DCE5 test to force write back on cayman and newer but
also any APU such as PALM or SUMO family
v5: Rebase on top of new uint64 fence patch
v6: Just break if seq doesn't change any more. Use radeon_fence
prefix for all function names. Even if it's now highly optimized,
try avoiding polling to often.
v7: We should never poll the last_seq from the hardware without
waking the sleeping threads, otherwise we might lose events.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Christian König <deathsimple@vodafone.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index cdf46bc..7c87117 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -263,15 +263,12 @@
atomic64_t last_seq;
unsigned long last_activity;
wait_queue_head_t queue;
- struct list_head emitted;
- struct list_head signaled;
bool initialized;
};
struct radeon_fence {
struct radeon_device *rdev;
struct kref kref;
- struct list_head list;
/* protected by radeon_fence.lock */
uint64_t seq;
/* RB, DMA, etc. */
@@ -291,7 +288,7 @@
int radeon_fence_wait_empty(struct radeon_device *rdev, int ring);
struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence);
void radeon_fence_unref(struct radeon_fence **fence);
-int radeon_fence_count_emitted(struct radeon_device *rdev, int ring);
+unsigned radeon_fence_count_emitted(struct radeon_device *rdev, int ring);
/*
* Tiling registers
@@ -1534,7 +1531,6 @@
struct radeon_mode_info mode_info;
struct radeon_scratch scratch;
struct radeon_mman mman;
- rwlock_t fence_lock;
struct radeon_fence_driver fence_drv[RADEON_NUM_RINGS];
struct radeon_semaphore_driver semaphore_drv;
struct mutex ring_lock;