Commit cb2ce93e authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gem: Differentiate oom failures from invalid map types 



After a cursory check on the parameters to i915_gem_object_pin_map(),
where we return a precise error, if the backend rejects the mapping we
always return PTR_ERR(-ENOMEM). Let us also return a more precise error
here so we can differentiate between running out of memory and
programming errors (or situations where we may be trying different paths
and looking for an error from an unsupported map).

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127195334.13134-1-chris@chris-wilson.co.uk
parent d2cf0125

drivers/gpu/drm/i915/gem/i915_gem_pages.c

+12 −14
Original line number Diff line number Diff line
@@ -281,7 +281,7 @@ static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj, 
		/* Too big for stack -- allocate temporary array instead */

		pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);

		if (!pages)

			return NULL;

			return ERR_PTR(-ENOMEM);

	}



	i = 0;
@@ -305,13 +305,13 @@ static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj, 
	void *vaddr;



	if (type != I915_MAP_WC)

		return NULL;

		return ERR_PTR(-ENODEV);



	if (n_pfn > ARRAY_SIZE(stack)) {

		/* Too big for stack -- allocate temporary array instead */

		pfns = kvmalloc_array(n_pfn, sizeof(*pfns), GFP_KERNEL);

		if (!pfns)

			return NULL;

			return ERR_PTR(-ENOMEM);

	}



	i = 0;
@@ -349,8 +349,10 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, 
			GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj));



			err = ____i915_gem_object_get_pages(obj);

			if (err)

				goto err_unlock;

			if (err) {

				ptr = ERR_PTR(err);

				goto out_unlock;

			}



			smp_mb__before_atomic();

		}
@@ -362,7 +364,7 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, 
	ptr = page_unpack_bits(obj->mm.mapping, &has_type);

	if (ptr && has_type != type) {

		if (pinned) {

			err = -EBUSY;

			ptr = ERR_PTR(-EBUSY);

			goto err_unpin;

		}
@@ -374,15 +376,13 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, 
	if (!ptr) {

		if (GEM_WARN_ON(type == I915_MAP_WC &&

				!static_cpu_has(X86_FEATURE_PAT)))

			ptr = NULL;

			ptr = ERR_PTR(-ENODEV);

		else if (i915_gem_object_has_struct_page(obj))

			ptr = i915_gem_object_map_page(obj, type);

		else

			ptr = i915_gem_object_map_pfn(obj, type);

		if (!ptr) {

			err = -ENOMEM;

		if (IS_ERR(ptr))

			goto err_unpin;

		}



		obj->mm.mapping = page_pack_bits(ptr, type);

	}
@@ -393,8 +393,6 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, 


err_unpin:

	atomic_dec(&obj->mm.pages_pin_count);

err_unlock:

	ptr = ERR_PTR(err);

	goto out_unlock;

}