drm/radeon: add an exclusive lock for GPU reset v2
GPU reset need to be exclusive, one happening at a time. For this
add a rw semaphore so that any path that trigger GPU activities
have to take the semaphore as a reader thus allowing concurency.
The GPU reset path take the semaphore as a writer ensuring that
no concurrent reset take place.
v2: init rw semaphore
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index d9b0809..b0be9c4 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -215,12 +215,14 @@
uint32_t handle;
int r;
+ down_read(&rdev->exclusive_lock);
/* create a gem object to contain this object in */
args->size = roundup(args->size, PAGE_SIZE);
r = radeon_gem_object_create(rdev, args->size, args->alignment,
args->initial_domain, false,
false, &gobj);
if (r) {
+ up_read(&rdev->exclusive_lock);
r = radeon_gem_handle_lockup(rdev, r);
return r;
}
@@ -228,10 +230,12 @@
/* drop reference from allocate - handle holds it now */
drm_gem_object_unreference_unlocked(gobj);
if (r) {
+ up_read(&rdev->exclusive_lock);
r = radeon_gem_handle_lockup(rdev, r);
return r;
}
args->handle = handle;
+ up_read(&rdev->exclusive_lock);
return 0;
}
@@ -240,6 +244,7 @@
{
/* transition the BO to a domain -
* just validate the BO into a certain domain */
+ struct radeon_device *rdev = dev->dev_private;
struct drm_radeon_gem_set_domain *args = data;
struct drm_gem_object *gobj;
struct radeon_bo *robj;
@@ -247,10 +252,12 @@
/* for now if someone requests domain CPU -
* just make sure the buffer is finished with */
+ down_read(&rdev->exclusive_lock);
/* just do a BO wait for now */
gobj = drm_gem_object_lookup(dev, filp, args->handle);
if (gobj == NULL) {
+ up_read(&rdev->exclusive_lock);
return -ENOENT;
}
robj = gem_to_radeon_bo(gobj);
@@ -258,6 +265,7 @@
r = radeon_gem_set_domain(gobj, args->read_domains, args->write_domain);
drm_gem_object_unreference_unlocked(gobj);
+ up_read(&rdev->exclusive_lock);
r = radeon_gem_handle_lockup(robj->rdev, r);
return r;
}