On 25/04/2018 13:37, Chris Wilson wrote:
When filling the ring to align the emit pointer to the next cacheline,
use memset64() rather than open-coding it. As we know that we always
have an even number of dwords, we can replace the dword loop with the
qword equivalent.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index c68ac605b8a9..07a9a2b4beb7 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1717,22 +1717,24 @@ u32 *intel_ring_begin(struct i915_request *rq, unsigned int num_dwords)
/* Align the ring tail to a cacheline boundary */
int intel_ring_cacheline_align(struct i915_request *rq)
{
- int num_dwords = (rq->ring->emit & (CACHELINE_BYTES - 1)) / sizeof(u32);
- u32 *cs;
+ int num_dwords;
+ void *cs;
+ num_dwords = (rq->ring->emit & (CACHELINE_BYTES - 1)) / sizeof(u32);
if (num_dwords == 0)
return 0;
- num_dwords = CACHELINE_BYTES / sizeof(u32) - num_dwords;
+ num_dwords = CACHELINE_DWORDS - num_dwords;
+ GEM_BUG_ON(num_dwords & 1);
+
cs = intel_ring_begin(rq, num_dwords);
if (IS_ERR(cs))
return PTR_ERR(cs);
- while (num_dwords--)
- *cs++ = MI_NOOP;
-
BUILD_BUG_ON(MI_NOOP != 0) for paranoid future proofing, since MI_NOOP
is now not mentioned in this function, but is meant.
+ memset64(cs, 0, num_dwords/2);
Spaces around '/' to appease checkpatch and our style.
intel_ring_advance(rq, cs);
+ GEM_BUG_ON(rq->ring->emit & CACHELINE_BYTES);
return 0;
}
With whitespace fixed, and preferably BUILD_BUG_ON:
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Regards,
Tvrtko
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