From: Chris Wilson Date: Mon, 19 Mar 2018 12:35:28 +0000 (+0000) Subject: drm/i915: Prefer memset64() when filling the iomap X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=46b863325c2f58b564463c4d6e66ee0d4f2f3244;p=linux.git drm/i915: Prefer memset64() when filling the iomap As the ringbuffer may exist inside stolen memory, our access to it may be via the GTT iomap. This implies we may only have WC access for which the conventional memset() substitution of rep stos performs very badly, so switch to the rep mov[dq] variants when available. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Matthew Auld Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20180319123528.28249-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 72d6167c519a6..04d9d9a946a77 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1693,17 +1693,18 @@ u32 *intel_ring_begin(struct i915_request *rq, unsigned int num_dwords) need_wrap &= ~1; GEM_BUG_ON(need_wrap > ring->space); GEM_BUG_ON(ring->emit + need_wrap > ring->size); + GEM_BUG_ON(!IS_ALIGNED(need_wrap, sizeof(u64))); /* Fill the tail with MI_NOOP */ - memset(ring->vaddr + ring->emit, 0, need_wrap); - ring->emit = 0; + memset64(ring->vaddr + ring->emit, 0, need_wrap / sizeof(u64)); ring->space -= need_wrap; + ring->emit = 0; } GEM_BUG_ON(ring->emit > ring->size - bytes); GEM_BUG_ON(ring->space < bytes); cs = ring->vaddr + ring->emit; - GEM_DEBUG_EXEC(memset(cs, POISON_INUSE, bytes)); + GEM_DEBUG_EXEC(memset32(cs, POISON_INUSE, bytes / sizeof(*cs))); ring->emit += bytes; ring->space -= bytes;