[PATCH v8 06/10] drm/i915: sanitize mem_flags for stolen buffers

From: Robert Beckett
Date: Tue Jun 21 2022 - 16:01:45 EST


Stolen regions are not page backed or considered iomem.
Prevent flags indicating such.
This correctly prevents stolen buffers from attempting to directly map
them.

See i915_gem_object_has_struct_page() and i915_gem_object_has_iomem()
usage for where it would break otherwise.

Signed-off-by: Robert Beckett <bob.beckett@xxxxxxxxxxxxx>
Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
index 675e9ab30396..81c67ca9edda 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c
@@ -14,6 +14,7 @@
#include "gem/i915_gem_region.h"
#include "gem/i915_gem_ttm.h"
#include "gem/i915_gem_ttm_move.h"
+#include "gem/i915_gem_stolen.h"

#include "gt/intel_engine_pm.h"
#include "gt/intel_gt.h"
@@ -124,8 +125,9 @@ void i915_ttm_adjust_gem_after_move(struct drm_i915_gem_object *obj)

obj->mem_flags &= ~(I915_BO_FLAG_STRUCT_PAGE | I915_BO_FLAG_IOMEM);

- obj->mem_flags |= i915_ttm_cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM :
- I915_BO_FLAG_STRUCT_PAGE;
+ if (!i915_gem_object_is_stolen(obj))
+ obj->mem_flags |= i915_ttm_cpu_maps_iomem(bo->resource) ? I915_BO_FLAG_IOMEM :
+ I915_BO_FLAG_STRUCT_PAGE;

if (!obj->ttm.cache_level_override) {
cache_level = i915_ttm_cache_level(to_i915(bo->base.dev),
--
2.25.1