commit
753b1ad4a281b0663329409d410243e91825c323 upstream.
intel_ring_cachline_align() emits MI_NOOPs until the ring tail is
aligned to a cacheline boundary.
Cc: Bjoern C <lkml@call-home.ch>
Cc: Alexandru DAMIAN <alexandru.damian@intel.com>
Cc: Enrico Tagliavini <enrico.tagliavini@gmail.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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_advance(struct intel_ring_buffer *ring)
{
ring->tail &= ring->size - 1;
}
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)