drm/radeon/kms: forbid big bo allocation (fdo 31708) v3

Forbid allocating buffer bigger than visible VRAM or GTT, also
properly set lpfn field.

v2 - use max macro
   - silence warning
v3 - don't explicitly set range limit
   - use min macro

Cc: stable <stable@kernel.org>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_object.c

@@ -69,7 +69,7 @@ void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain)
 	u32 c = 0;
 
 	rbo->placement.fpfn = 0;
-	rbo->placement.lpfn = rbo->rdev->mc.active_vram_size >> PAGE_SHIFT;
+	rbo->placement.lpfn = 0;
 	rbo->placement.placement = rbo->placements;
 	rbo->placement.busy_placement = rbo->placements;
 	if (domain & RADEON_GEM_DOMAIN_VRAM)
@@ -91,7 +91,8 @@ int radeon_bo_create(struct radeon_device *rdev, struct drm_gem_object *gobj,
 {
 	struct radeon_bo *bo;
 	enum ttm_bo_type type;
-	int page_align = roundup(byte_align, PAGE_SIZE) >> PAGE_SHIFT;
+	unsigned long page_align = roundup(byte_align, PAGE_SIZE) >> PAGE_SHIFT;
+	unsigned long max_size = 0;
 	int r;
 
 	if (unlikely(rdev->mman.bdev.dev_mapping == NULL)) {
@@ -104,6 +105,14 @@ int radeon_bo_create(struct radeon_device *rdev, struct drm_gem_object *gobj,
 	}
 	*bo_ptr = NULL;
 
+	/* maximun bo size is the minimun btw visible vram and gtt size */
+	max_size = min(rdev->mc.visible_vram_size, rdev->mc.gtt_size);
+	if ((page_align << PAGE_SHIFT) >= max_size) {
+		printk(KERN_WARNING "%s:%d alloc size %ldM bigger than %ldMb limit\n",
+			__func__, __LINE__, page_align  >> (20 - PAGE_SHIFT), max_size >> 20);
+		return -ENOMEM;
+	}
+
 retry:
 	bo = kzalloc(sizeof(struct radeon_bo), GFP_KERNEL);
 	if (bo == NULL)