drm/i915: Allow i915_gem_object_get_page() on userptr as well

commit 033908aed5a596f6202c848c6bbc8a40fb1a8490
Author: Dave Gordon <david.s.gordon@intel.com>
Date:   Thu Dec 10 18:51:23 2015 +0000

    drm/i915: mark GEM object pages dirty when mapped & written by the CPU

introduced a check into i915_gem_object_get_dirty_pages() that returned
a NULL pointer when called with a bad object, one that was not backed by
shmemfs. This WARN was too strict as we can work on all struct page
backed objects, and resulted in a WARN + GPF for existing userspace. In
order to differentiate the various types of objects, add a new flags field
to the i915_gem_object_ops struct to describe their capabilities, with
the first flag being whether the object has struct pages.

v2: Drop silly const before an integer in the structure declaration.

Testcase: igt/gem_userptr_blits/relocations
Reported-and-tested-by: Kristian Høgsberg Kristensen <krh@bitplanet.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: Kristian Høgsberg Kristensen <krh@bitplanet.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Kristian Høgsberg Kristensen <krh@bitplanet.net>
Tested-by: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453487551-16799-1-git-send-email-chris@chris-wilson.co.uk

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 65a2cd04bc8f..77227a39f3d5 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2038,6 +2038,9 @@ enum hdmi_force_audio {
 #define I915_GTT_OFFSET_NONE ((u32)-1)
 
 struct drm_i915_gem_object_ops {
+	unsigned int flags;
+#define I915_GEM_OBJECT_HAS_STRUCT_PAGE 0x1
+
 	/* Interface between the GEM object and its backing storage.
 	 * get_pages() is called once prior to the use of the associated set
 	 * of pages before to binding them into the GTT, and put_pages() is
@@ -2053,6 +2056,7 @@ struct drm_i915_gem_object_ops {
 	 */
 	int (*get_pages)(struct drm_i915_gem_object *);
 	void (*put_pages)(struct drm_i915_gem_object *);
+
 	int (*dmabuf_export)(struct drm_i915_gem_object *);
 	void (*release)(struct drm_i915_gem_object *);
 };