[Intel-gfx] [PATCH 1/2] drm/i915: clear the shadow batch

[Matthew Auld]

The shadow batch is an internal object, which doesn't have any page
clearing, and since the batch_len can be smaller than the object, we
should take care to clear it.

Testcase: igt/gen9_exec_parse/shadow-peek
Fixes: 4f7af1948abc ("drm/i915: Support ro ppgtt mapped cmdparser shadow buffers")
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
---
 drivers/gpu/drm/i915/i915_cmd_parser.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 8d88402387bd..ff3a0b8ccdd5 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -1147,6 +1147,13 @@ static u32 *copy_batch(struct drm_i915_gem_object *dst_obj,
 	if (IS_ERR(dst))
 		return dst;
 
+	if (length < dst_obj->base.size) {
+		memset32(dst + length, 0,
+			 (dst_obj->base.size - length) / sizeof(u32));
+		__i915_gem_object_flush_map(dst_obj, length,
+					    dst_obj->base.size - length);
+	}
+
 	ret = i915_gem_object_pin_pages(src_obj);
 	if (ret) {
 		i915_gem_object_unpin_map(dst_obj);
-- 
2.26.2