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Commit 10466d2a authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Fix phys pwrite for struct_mutex-less operation 



Since commit fe115628 ("drm/i915: Implement pwrite without
struct-mutex") the lowlevel pwrite calls are now called without the
protection of struct_mutex, but pwrite_phys was still asserting that it
held the struct_mutex and later tried to drop and relock it.

Fixes: fe115628 ("drm/i915: Implement pwrite without struct-mutex")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <drm-intel-fixes@lists.freedesktop.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170106152240.5793-1-chris@chris-wilson.co.uk


Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
parent 984ff29f

drivers/gpu/drm/i915/i915_gem.c

+4 −30
Original line number Diff line number Diff line
@@ -597,47 +597,21 @@ i915_gem_phys_pwrite(struct drm_i915_gem_object *obj, 
		     struct drm_i915_gem_pwrite *args,

		     struct drm_file *file)

{

	struct drm_device *dev = obj->base.dev;

	void *vaddr = obj->phys_handle->vaddr + args->offset;

	char __user *user_data = u64_to_user_ptr(args->data_ptr);

	int ret;



	/* We manually control the domain here and pretend that it

	 * remains coherent i.e. in the GTT domain, like shmem_pwrite.

	 */

	lockdep_assert_held(&obj->base.dev->struct_mutex);

	ret = i915_gem_object_wait(obj,

				   I915_WAIT_INTERRUPTIBLE |

				   I915_WAIT_LOCKED |

				   I915_WAIT_ALL,

				   MAX_SCHEDULE_TIMEOUT,

				   to_rps_client(file));

	if (ret)

		return ret;



	intel_fb_obj_invalidate(obj, ORIGIN_CPU);

	if (__copy_from_user_inatomic_nocache(vaddr, user_data, args->size)) {

		unsigned long unwritten;



		/* The physical object once assigned is fixed for the lifetime

		 * of the obj, so we can safely drop the lock and continue

		 * to access vaddr.

		 */

		mutex_unlock(&dev->struct_mutex);

		unwritten = copy_from_user(vaddr, user_data, args->size);

		mutex_lock(&dev->struct_mutex);

		if (unwritten) {

			ret = -EFAULT;

			goto out;

		}

	}

	if (copy_from_user(vaddr, user_data, args->size))

		return -EFAULT;



	drm_clflush_virt_range(vaddr, args->size);

	i915_gem_chipset_flush(to_i915(dev));

	i915_gem_chipset_flush(to_i915(obj->base.dev));



out:

	intel_fb_obj_flush(obj, false, ORIGIN_CPU);

	return ret;

	return 0;

}



void *i915_gem_object_alloc(struct drm_i915_private *dev_priv)