[PATCH 04/15] drm/i915: Virtualize the ringbuffer signal func

[Ben Widawsky <benjamin.widawsky@intel.com>]

This abstraction again is in preparation for gen8. Gen8 will bring new
semantics for doing this operation.

While here, make the writes of MI_NOOPs explicit for non-existent rings.
This should have been implicit before.

NOTE: This is going to be removed in a few patches.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c | 40 ++++++++++++++++++++-------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  2 ++
 2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index cc75205..e638ff1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -632,20 +632,32 @@ static void render_ring_cleanup(struct intel_ring_buffer *ring)
 	ring->scratch.obj = NULL;
 }
 
-static void
-update_mboxes(struct intel_ring_buffer *ring,
-	      u32 mmio_offset)
+static void gen6_signal(struct intel_ring_buffer *signaller)
 {
+	struct drm_i915_private *dev_priv = signaller->dev->dev_private;
+	struct intel_ring_buffer *useless;
+	int i;
+
 /* NB: In order to be able to do semaphore MBOX updates for varying number
  * of rings, it's easiest if we round up each individual update to a
  * multiple of 2 (since ring updates must always be a multiple of 2)
  * even though the actual update only requires 3 dwords.
  */
 #define MBOX_UPDATE_DWORDS 4
-	intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
-	intel_ring_emit(ring, mmio_offset);
-	intel_ring_emit(ring, ring->outstanding_lazy_seqno);
-	intel_ring_emit(ring, MI_NOOP);
+	for_each_ring(useless, dev_priv, i) {
+		u32 mbox_reg = signaller->semaphore.signal_mbox[i];
+		if (mbox_reg != GEN6_NOSYNC) {
+			intel_ring_emit(signaller, MI_LOAD_REGISTER_IMM(1));
+			intel_ring_emit(signaller, mbox_reg);
+			intel_ring_emit(signaller, signaller->outstanding_lazy_seqno);
+			intel_ring_emit(signaller, MI_NOOP);
+		} else {
+			intel_ring_emit(signaller, MI_NOOP);
+			intel_ring_emit(signaller, MI_NOOP);
+			intel_ring_emit(signaller, MI_NOOP);
+			intel_ring_emit(signaller, MI_NOOP);
+		}
+	}
 }
 
 /**
@@ -661,9 +673,7 @@ static int
 gen6_add_request(struct intel_ring_buffer *ring)
 {
 	struct drm_device *dev = ring->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_ring_buffer *useless;
-	int i, ret, num_dwords = 4;
+	int ret, num_dwords = 4;
 
 	if (i915_semaphore_is_enabled(dev))
 		num_dwords += ((I915_NUM_RINGS-1) * MBOX_UPDATE_DWORDS);
@@ -673,11 +683,7 @@ gen6_add_request(struct intel_ring_buffer *ring)
 	if (ret)
 		return ret;
 
-	for_each_ring(useless, dev_priv, i) {
-		u32 mbox_reg = ring->semaphore.signal_mbox[i];
-		if (mbox_reg != GEN6_NOSYNC)
-			update_mboxes(ring, mbox_reg);
-	}
+	ring->semaphore.signal(ring);
 
 	intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
 	intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
@@ -1866,6 +1872,7 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
 		ring->get_seqno = gen6_ring_get_seqno;
 		ring->set_seqno = ring_set_seqno;
 		ring->semaphore.sync_to = gen6_ring_sync;
+		ring->semaphore.signal = gen6_signal;
 		ring->semaphore.mbox[RCS] = MI_SEMAPHORE_SYNC_INVALID;
 		ring->semaphore.mbox[VCS] = MI_SEMAPHORE_SYNC_RV;
 		ring->semaphore.mbox[BCS] = MI_SEMAPHORE_SYNC_RB;
@@ -2042,6 +2049,7 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
 				gen6_ring_dispatch_execbuffer;
 		}
 		ring->semaphore.sync_to = gen6_ring_sync;
+		ring->semaphore.signal = gen6_signal;
 		ring->semaphore.mbox[RCS] = MI_SEMAPHORE_SYNC_VR;
 		ring->semaphore.mbox[VCS] = MI_SEMAPHORE_SYNC_INVALID;
 		ring->semaphore.mbox[BCS] = MI_SEMAPHORE_SYNC_VB;
@@ -2099,6 +2107,7 @@ int intel_init_blt_ring_buffer(struct drm_device *dev)
 		ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
 	}
 	ring->semaphore.sync_to = gen6_ring_sync;
+	ring->semaphore.signal = gen6_signal;
 	ring->semaphore.mbox[RCS] = MI_SEMAPHORE_SYNC_BR;
 	ring->semaphore.mbox[VCS] = MI_SEMAPHORE_SYNC_BV;
 	ring->semaphore.mbox[BCS] = MI_SEMAPHORE_SYNC_INVALID;
@@ -2140,6 +2149,7 @@ int intel_init_vebox_ring_buffer(struct drm_device *dev)
 		ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
 	}
 	ring->semaphore.sync_to = gen6_ring_sync;
+	ring->semaphore.signal = gen6_signal;
 	ring->semaphore.mbox[RCS] = MI_SEMAPHORE_SYNC_VER;
 	ring->semaphore.mbox[VCS] = MI_SEMAPHORE_SYNC_VEV;
 	ring->semaphore.mbox[BCS] = MI_SEMAPHORE_SYNC_VEB;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index b5fc768..e01a1ff 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -121,6 +121,8 @@ struct  intel_ring_buffer {
 		u32		mbox[I915_NUM_RINGS];
 		/* mboxes this ring signals to */
 		u32		signal_mbox[I915_NUM_RINGS];
+
+		void		(*signal)(struct intel_ring_buffer *signaller);
 	} semaphore;
 
 	/**
-- 
1.8.5.1