[Intel-gfx] [PATCH] drm/i915: Declare i915_gem_object_create_internal() as taking phys_addr_t size

[Chris Wilson]

The internal object is a collection of struct pages and so is
intrinsically linked to the available physical memory on the machine,
and not an arbitrary type from the uabi. Use phys_addr_t so the link
between size and memory consumption is clear, and then double check that
we don't overflow the maximum object size.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h          | 2 +-
 drivers/gpu/drm/i915/i915_gem_internal.c | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b84c1d1fa12c..d8635d2af7ad 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3506,7 +3506,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_i915_private *dev_priv
 /* i915_gem_internal.c */
 struct drm_i915_gem_object *
 i915_gem_object_create_internal(struct drm_i915_private *dev_priv,
-				unsigned int size);
+				phys_addr_t size);
 
 /* i915_gem_shrinker.c */
 unsigned long i915_gem_shrink(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/i915_gem_internal.c b/drivers/gpu/drm/i915/i915_gem_internal.c
index 2222863e505f..9fd3d94e0e9f 100644
--- a/drivers/gpu/drm/i915/i915_gem_internal.c
+++ b/drivers/gpu/drm/i915/i915_gem_internal.c
@@ -151,10 +151,13 @@ static const struct drm_i915_gem_object_ops i915_gem_object_internal_ops = {
  */
 struct drm_i915_gem_object *
 i915_gem_object_create_internal(struct drm_i915_private *i915,
-				unsigned int size)
+				phys_addr_t size)
 {
 	struct drm_i915_gem_object *obj;
 
+	if (overflows_type(size, obj->base.size))
+		return ERR_PTR(-E2BIG);
+
 	obj = i915_gem_object_alloc(i915);
 	if (!obj)
 		return ERR_PTR(-ENOMEM);
-- 
2.11.0