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_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index d5aec09..553da67 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -499,7 +499,9 @@
struct radeon_cs_parser parser;
int r;
+ down_read(&rdev->exclusive_lock);
if (!rdev->accel_working) {
+ up_read(&rdev->exclusive_lock);
return -EBUSY;
}
/* initialize parser */
@@ -512,6 +514,7 @@
if (r) {
DRM_ERROR("Failed to initialize parser !\n");
radeon_cs_parser_fini(&parser, r);
+ up_read(&rdev->exclusive_lock);
r = radeon_cs_handle_lockup(rdev, r);
return r;
}
@@ -520,6 +523,7 @@
if (r != -ERESTARTSYS)
DRM_ERROR("Failed to parse relocation %d!\n", r);
radeon_cs_parser_fini(&parser, r);
+ up_read(&rdev->exclusive_lock);
r = radeon_cs_handle_lockup(rdev, r);
return r;
}
@@ -533,6 +537,7 @@
}
out:
radeon_cs_parser_fini(&parser, r);
+ up_read(&rdev->exclusive_lock);
r = radeon_cs_handle_lockup(rdev, r);
return r;
}