drm/radeon/kms: implement timestamp userspace query (v2)

Returns a snapshot of the GPU clock counter.  Needed
for certain OpenGL extensions.

v2: agd5f
- address Jerome's comments
- add function documentation

Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 742af8244e8..d2e243867ac 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1009,6 +1009,7 @@ int radeon_device_init(struct radeon_device *rdev,
 	atomic_set(&rdev->ih.lock, 0);
 	mutex_init(&rdev->gem.mutex);
 	mutex_init(&rdev->pm.mutex);
+	mutex_init(&rdev->gpu_clock_mutex);
 	init_rwsem(&rdev->pm.mclk_lock);
 	init_rwsem(&rdev->exclusive_lock);
 	init_waitqueue_head(&rdev->irq.vblank_queue);