Move calls to unmap the buffer-object memory from the object-release
code in xe_gem_object_free() to the caller of the release.
Doing an unmap for a BO requires holding the reservation lock, which
is not allowed while releasing a GEM object. Without the reservation
lock, TTM can concurrently evict the buffer object that is to be
released; making the mapping invalid.
Pushing the unmap calls, namely xe_bo_vunmap(), releases the mapped
pages before the buffer object.
While at it, add a warning about buffer mappings to the GEM-object
release code. The warning message and unmap code can be removed after
the driver has been audited to not release mapped buffer objects.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/xe/display/intel_fb_bo.c | 12 +++++++-----
drivers/gpu/drm/xe/xe_bo.c | 14 +++++++++++++-
drivers/gpu/drm/xe/xe_bo.h | 23 ++++++++++++-----------
drivers/gpu/drm/xe/xe_lrc.c | 1 +
4 files changed, 33 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/xe/display/intel_fb_bo.c b/drivers/gpu/drm/xe/display/intel_fb_bo.c
index f835492f73fb4..cf2720dbdd51f 100644
--- a/drivers/gpu/drm/xe/display/intel_fb_bo.c
+++ b/drivers/gpu/drm/xe/display/intel_fb_bo.c
@@ -12,12 +12,14 @@
void intel_fb_bo_framebuffer_fini(struct xe_bo *bo)
{
- if (bo->flags & XE_BO_FLAG_PINNED) {
- /* Unpin our kernel fb first */
- xe_bo_lock(bo, false);
+ xe_bo_lock(bo, false);
+ xe_bo_vunmap(bo);
+
+ /* Unpin our kernel fb first */
+ if (bo->flags & XE_BO_FLAG_PINNED)
xe_bo_unpin(bo);
- xe_bo_unlock(bo);
- }
+
+ xe_bo_unlock(bo);
xe_bo_put(bo);
}
diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 2bae01ce4e5b9..a98d857ff1e5a 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -1093,6 +1093,19 @@ static void xe_ttm_bo_destroy(struct ttm_buffer_object *ttm_bo)
static void xe_gem_object_free(struct drm_gem_object *obj)
{
+ struct xe_bo *bo = gem_to_xe_bo(obj);
+
+ /*
+ * Trying to free the object with a mapping in place. Resolve
+ * this warning by calling xe_bo_vunmap() in the code that leads
+ * ot this object release.
+ *
+ * TODO: Audit the driver to not release mapped buffer objects and
+ * then remove this block.
+ */
+ if (drm_WARN_ON(obj->dev, !iosys_map_is_null(&bo->vmap)))
+ __xe_bo_vunmap(bo);
+
/* Our BO reference counting scheme works as follows:
*
* The gem object kref is typically used throughout the driver,
@@ -1106,7 +1119,6 @@ static void xe_gem_object_free(struct drm_gem_object *obj)
* driver ttm callbacks is allowed to use the ttm_buffer_object
* refcount directly if needed.
*/
- __xe_bo_vunmap(gem_to_xe_bo(obj));
ttm_bo_put(container_of(obj, struct ttm_buffer_object, base));
}
diff --git a/drivers/gpu/drm/xe/xe_bo.h b/drivers/gpu/drm/xe/xe_bo.h
index 6de894c728f54..5d1f8f13fbf13 100644
--- a/drivers/gpu/drm/xe/xe_bo.h
+++ b/drivers/gpu/drm/xe/xe_bo.h
@@ -170,17 +170,6 @@ static inline bool xe_bo_is_pinned(struct xe_bo *bo)
return bo->ttm.pin_count;
}
-static inline void xe_bo_unpin_map_no_vm(struct xe_bo *bo)
-{
- if (likely(bo)) {
- xe_bo_lock(bo, false);
- xe_bo_unpin(bo);
- xe_bo_unlock(bo);
-
- xe_bo_put(bo);
- }
-}
-
bool xe_bo_is_xe_bo(struct ttm_buffer_object *bo);
dma_addr_t __xe_bo_addr(struct xe_bo *bo, u64 offset, size_t page_size);
dma_addr_t xe_bo_addr(struct xe_bo *bo, u64 offset, size_t page_size);
@@ -202,6 +191,18 @@ xe_bo_ggtt_addr(struct xe_bo *bo)
int xe_bo_vmap(struct xe_bo *bo);
void xe_bo_vunmap(struct xe_bo *bo);
+static inline void xe_bo_unpin_map_no_vm(struct xe_bo *bo)
+{
+ if (likely(bo)) {
+ xe_bo_lock(bo, false);
+ xe_bo_vunmap(bo);
+ xe_bo_unpin(bo);
+ xe_bo_unlock(bo);
+
+ xe_bo_put(bo);
+ }
+}
+
bool mem_type_is_vram(u32 mem_type);
bool xe_bo_is_vram(struct xe_bo *bo);
bool xe_bo_is_stolen(struct xe_bo *bo);
diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
index 3a68fe6d592ed..8a52797fe79bb 100644
--- a/drivers/gpu/drm/xe/xe_lrc.c
+++ b/drivers/gpu/drm/xe/xe_lrc.c
@@ -812,6 +812,7 @@ static void xe_lrc_finish(struct xe_lrc *lrc)
{
xe_hw_fence_ctx_finish(&lrc->fence_ctx);
xe_bo_lock(lrc->bo, false);
+ xe_bo_vunmap(lrc->bo);
xe_bo_unpin(lrc->bo);
xe_bo_unlock(lrc->bo);
xe_bo_put(lrc->bo);
--
2.45.2
