drm/radeon: Make sure CS mutex is held across GPU reset.

This was only the case if the GPU reset was triggered from the CS ioctl,
otherwise other processes could happily enter the CS ioctl and wreak havoc
during the GPU reset.

This is a little complicated because the GPU reset can be triggered from the
CS ioctl, in which case we're already holding the mutex, or from other call
paths, in which case we need to lock the mutex. AFAICT the mutex API doesn't
allow recursive locking or finding out the mutex owner, so we need to handle
this with helper functions which allow recursive locking from the same
process.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index fae00c0d75aa..ccaa243c1442 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -222,7 +222,7 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	struct radeon_cs_chunk *ib_chunk;
 	int r;
 
-	mutex_lock(&rdev->cs_mutex);
+	radeon_mutex_lock(&rdev->cs_mutex);
 	/* initialize parser */
 	memset(&parser, 0, sizeof(struct radeon_cs_parser));
 	parser.filp = filp;
@@ -233,14 +233,14 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	if (r) {
 		DRM_ERROR("Failed to initialize parser !\n");
 		radeon_cs_parser_fini(&parser, r);
-		mutex_unlock(&rdev->cs_mutex);
+		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	r =  radeon_ib_get(rdev, &parser.ib);
 	if (r) {
 		DRM_ERROR("Failed to get ib !\n");
 		radeon_cs_parser_fini(&parser, r);
-		mutex_unlock(&rdev->cs_mutex);
+		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	r = radeon_cs_parser_relocs(&parser);
@@ -248,7 +248,7 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 		if (r != -ERESTARTSYS)
 			DRM_ERROR("Failed to parse relocation %d!\n", r);
 		radeon_cs_parser_fini(&parser, r);
-		mutex_unlock(&rdev->cs_mutex);
+		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	/* Copy the packet into the IB, the parser will read from the
@@ -260,14 +260,14 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	if (r || parser.parser_error) {
 		DRM_ERROR("Invalid command stream !\n");
 		radeon_cs_parser_fini(&parser, r);
-		mutex_unlock(&rdev->cs_mutex);
+		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	r = radeon_cs_finish_pages(&parser);
 	if (r) {
 		DRM_ERROR("Invalid command stream !\n");
 		radeon_cs_parser_fini(&parser, r);
-		mutex_unlock(&rdev->cs_mutex);
+		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	r = radeon_ib_schedule(rdev, parser.ib);
@@ -275,7 +275,7 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 		DRM_ERROR("Failed to schedule IB !\n");
 	}
 	radeon_cs_parser_fini(&parser, r);
-	mutex_unlock(&rdev->cs_mutex);
+	radeon_mutex_unlock(&rdev->cs_mutex);
 	return r;
 }