From: Akash Goel <akash.goel@xxxxxxxxx>
On VLV, to clear out the contents of Frame buffers allocated from
stolen area, Blitter engine is being used, to avoid the waste of
CPU cycles in doing a sw based memset.
Signed-off-by: Akash Goel <akash.goel@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_stolen.c | 87 ++++++++++++++++++++++++++++++++--
1 file changed, 84 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 253a39a..10237c8 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -371,7 +371,84 @@ i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
return NULL;
}
-static void i915_memset_stolen_obj(struct drm_i915_gem_object *obj)
+static int i915_add_clear_obj_cmd(struct drm_i915_gem_object *obj)
+{
+ struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
+ struct intel_ring_buffer *ring = &dev_priv->ring[BCS];
+ uint32_t obj_height = (obj->base.size / obj->stride);
+ u32 offset = i915_gem_obj_ggtt_offset(obj);
+ int ret;
+
+#define COLOR_BLIT_OP ((0x2 << 29) | (0x40 << 22) | (0x3 << 20) | 0x3)
+#define COLOR_BLIT_OP_DW1 ((0x3 << 24) | (0xF0 << 16) | (obj->stride))
+#define COLOR_BLIT_OP_DW2 ((obj_height << 16) | (obj->stride))
+#define COLOR_BLIT_OP_DW3 (offset)
+#define COLOR_BLIT_OP_DW4 (0x0)
+
+ ret = intel_ring_begin(ring, 6);
+ if (ret)
+ return ret;
+ intel_ring_emit(ring, COLOR_BLIT_OP);
+ intel_ring_emit(ring, COLOR_BLIT_OP_DW1);
+ intel_ring_emit(ring, COLOR_BLIT_OP_DW2);
+ intel_ring_emit(ring, COLOR_BLIT_OP_DW3);
+ intel_ring_emit(ring, COLOR_BLIT_OP_DW4);
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_advance(ring);
+
+ return 0;
+}
+
+static int i915_memset_stolen_obj_hw(struct drm_i915_gem_object *obj)
+{
+ struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
+ struct intel_ring_buffer *ring = &dev_priv->ring[BCS];
+ unsigned alignment = 0;
+ bool map_and_fenceable = true;
+ bool nonblocking = false;
+ u32 seqno;
+ int ret;
+
+ ret = i915_gem_obj_ggtt_pin(obj, alignment, map_and_fenceable,
+ nonblocking);
+ if (ret) {
+ DRM_ERROR("Mapping of User FB to GTT failed\n");
+ return ret;
+ }
+
+ /* Adding commands to the blitter ring to
+ * clear out the contents of the buffer object
+ */
+ ret = i915_add_clear_obj_cmd(obj);
+ if (ret) {
+ DRM_ERROR("couldn't add commands in blitter ring\n");
+ i915_gem_object_ggtt_unpin(obj);
+ return ret;
+ }
+
+ seqno = intel_ring_get_seqno(ring);
+
+ /* Object now in render domain */
+ obj->base.read_domains = I915_GEM_DOMAIN_RENDER;
+ obj->base.write_domain = I915_GEM_DOMAIN_RENDER;
+
+ i915_vma_move_to_active(i915_gem_obj_to_ggtt(obj), ring);
+
+ obj->dirty = 1;
+ obj->last_write_seqno = seqno;
+
+ /* Unconditionally force add_request to emit a full flush. */
+ ring->gpu_caches_dirty = true;
+
+ /* Add a breadcrumb for the completion of the clear request */
+ (void)i915_add_request(ring, NULL);
+
+ i915_gem_object_ggtt_unpin(obj);
+
+ return 0;
+}
+
+static void i915_memset_stolen_obj_sw(struct drm_i915_gem_object *obj)
{
int ret;
char __iomem *base;
@@ -490,9 +567,13 @@ i915_gem_object_move_to_stolen(struct drm_i915_gem_object *obj)
obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
/* Zero-out the contents of the stolen object, otherwise we observe
- * corruptions in the display.
+ * corruptions in the display. First try using the blitter engine
+ * to clear the buffer contents
*/
- i915_memset_stolen_obj(obj);
+ ret = i915_memset_stolen_obj_hw(obj);
+ /* fallback to Sw based memset if Hw memset fails */
+ if (ret)
+ i915_memset_stolen_obj_sw(obj);
return;
cleanup:
--
1.8.5.2
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