Since we blow the TLB caches by using kmap/kunmap, we may as well go the
whole hog and see if declaring our destination page as WC is faster than
keeping it as WB and using clflush. It should be!
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_cmd_parser.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index f4d3e7dc3835..61248223f95b 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -918,8 +918,9 @@ int i915_parse_cmds(struct intel_engine_cs *ring,
struct drm_i915_cmd_descriptor default_desc = { CMD_DESC_SKIP };
const struct drm_i915_cmd_descriptor *desc = &default_desc;
u32 last_cmd_header = 0;
- int needs_clflush = 0;
void *src, *dst;
+ int src_needs_clflush = 0;
+ bool dst_needs_clflush;
unsigned in, out;
u32 *buf, partial = 0, length = 1;
bool oacontrol_set = false; /* OACONTROL tracking. See check_cmd() */
@@ -932,13 +933,17 @@ int i915_parse_cmds(struct intel_engine_cs *ring,
if (WARN_ON(shadow_batch_obj->pages_pin_count == 0))
return -ENODEV;
- ret = i915_gem_obj_prepare_shmem_read(batch_obj, &needs_clflush);
+ ret = i915_gem_obj_prepare_shmem_read(batch_obj, &src_needs_clflush);
if (ret) {
DRM_DEBUG_DRIVER("CMD: failed to prepare shadow batch\n");
return ret;
}
- ret = i915_gem_object_set_to_cpu_domain(shadow_batch_obj, true);
+ dst_needs_clflush = !INTEL_INFO(shadow_batch_obj->base.dev)->has_llc;
+ if (dst_needs_clflush)
+ ret = i915_gem_object_set_to_gtt_domain(shadow_batch_obj, true);
+ else
+ ret = i915_gem_object_set_to_cpu_domain(shadow_batch_obj, true);
if (ret) {
DRM_DEBUG_DRIVER("CMD: Failed to set shadow batch to CPU\n");
goto unpin;
@@ -972,7 +977,7 @@ int i915_parse_cmds(struct intel_engine_cs *ring,
this = PAGE_SIZE - in;
src = kmap_atomic(sg_page_iter_page(&src_iter));
- if (needs_clflush)
+ if (src_needs_clflush)
drm_clflush_virt_range(src + in, this);
i = this;
@@ -984,6 +989,8 @@ int i915_parse_cmds(struct intel_engine_cs *ring,
*/
if (out == PAGE_SIZE) {
__sg_page_iter_next(&dst_iter);
+ if (dst_needs_clflush)
+ drm_clflush_virt_range(dst, PAGE_SIZE);
kunmap_atomic(dst);
dst = kmap_atomic(sg_page_iter_page(&dst_iter));
out = 0;
@@ -1104,6 +1111,8 @@ check:
unmap:
kunmap_atomic(src);
+ if (dst_needs_clflush)
+ drm_clflush_virt_range(dst, PAGE_SIZE);
kunmap_atomic(dst);
unpin:
i915_gem_object_unpin_pages(batch_obj);
--
2.1.4
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