From 753b1ad4a281b0663329409d410243e91825c323 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Tue, 11 Feb 2014 19:52:05 +0200 Subject: [PATCH] drm/i915: Add intel_ring_cachline_align() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit intel_ring_cachline_align() emits MI_NOOPs until the ring tail is aligned to a cacheline boundary. Cc: Bjoern C Cc: Alexandru DAMIAN Cc: Enrico Tagliavini Suggested-by: Chris Wilson Signed-off-by: Ville Syrjälä Reviewed-by: Chris Wilson Cc: stable@vger.kernel.org (prereq for the next patch) Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_ringbuffer.c | 21 +++++++++++++++++++++ drivers/gpu/drm/i915/intel_ringbuffer.h | 1 + 2 files changed, 22 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index b7f1742..31b36c5 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1653,6 +1653,27 @@ int intel_ring_begin(struct intel_ring_buffer *ring, return 0; } +/* Align the ring tail to a cacheline boundary */ +int intel_ring_cacheline_align(struct intel_ring_buffer *ring) +{ + int num_dwords = (64 - (ring->tail & 63)) / sizeof(uint32_t); + int ret; + + if (num_dwords == 0) + return 0; + + ret = intel_ring_begin(ring, num_dwords); + if (ret) + return ret; + + while (num_dwords--) + intel_ring_emit(ring, MI_NOOP); + + intel_ring_advance(ring); + + return 0; +} + void intel_ring_init_seqno(struct intel_ring_buffer *ring, u32 seqno) { struct drm_i915_private *dev_priv = ring->dev->dev_private; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 71a73f4..0b243ce 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -233,6 +233,7 @@ intel_write_status_page(struct intel_ring_buffer *ring, void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring); int __must_check intel_ring_begin(struct intel_ring_buffer *ring, int n); +int __must_check intel_ring_cacheline_align(struct intel_ring_buffer *ring); static inline void intel_ring_emit(struct intel_ring_buffer *ring, u32 data) { -- 2.7.4