[Intel-gfx] [PATCH 04/13] drm/i915: Make semaphore updates more precise
Ben Widawsky
benjamin.widawsky at intel.com
Tue Apr 29 23:52:31 CEST 2014
With the ring mask we now have an easy way to know the number of rings
in the system, and therefore can accurately predict the number of dwords
to emit for semaphore signalling. This was not possible (easily)
previously.
There should be no functional impact, simply fewer instructions emitted.
While we're here, simply do the round up to 2 instead of the fancier
rounding we did before, which rounding up per mbox, ie 4. This also
allows us to drop the unnecessary MI_NOOP, so not really 4, 3.
v2: Use 3 dwords instead of 4 (Ville)
Do the proper calculation to get the number of dwords to emit (Ville)
Conditionally set .sync_to when semaphores are enabled (Ville)
v3: Rebased on VCS2
Replace hweight_long with hweight32 (Ville)
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com> (v1)
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 173 +++++++++++++++++---------------
1 file changed, 90 insertions(+), 83 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index e0c7bf2..7aedc0c 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -666,24 +666,19 @@ static void render_ring_cleanup(struct intel_ring_buffer *ring)
static int gen6_signal(struct intel_ring_buffer *signaller,
unsigned int num_dwords)
{
+#define MBOX_UPDATE_DWORDS 3
struct drm_device *dev = signaller->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_ring_buffer *useless;
- int i, ret;
+ int i, ret, num_rings;
- /* 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
- if (i915_semaphore_is_enabled(dev))
- num_dwords += ((I915_NUM_RINGS-1) * MBOX_UPDATE_DWORDS);
+ num_rings = hweight32(INTEL_INFO(dev)->ring_mask);
+ num_dwords += round_up((num_rings-1) * MBOX_UPDATE_DWORDS, 2);
+#undef MBOX_UPDATE_DWORDS
ret = intel_ring_begin(signaller, num_dwords);
if (ret)
return ret;
-#undef MBOX_UPDATE_DWORDS
for_each_ring(useless, dev_priv, i) {
u32 mbox_reg = signaller->semaphore.mbox.signal[i];
@@ -691,15 +686,13 @@ static int gen6_signal(struct intel_ring_buffer *signaller,
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);
}
}
+ /* If num_dwords was rounded, make sure the tail pointer is correct */
+ if (num_rings % 2 == 0)
+ intel_ring_emit(signaller, MI_NOOP);
+
return 0;
}
@@ -717,7 +710,11 @@ gen6_add_request(struct intel_ring_buffer *ring)
{
int ret;
- ret = ring->semaphore.signal(ring, 4);
+ if (ring->semaphore.signal)
+ ret = ring->semaphore.signal(ring, 4);
+ else
+ ret = intel_ring_begin(ring, 4);
+
if (ret)
return ret;
@@ -1928,24 +1925,27 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
ring->irq_enable_mask = GT_RENDER_USER_INTERRUPT;
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;
- /*
- * The current semaphore is only applied on pre-gen8 platform.
- * And there is no VCS2 ring on the pre-gen8 platform. So the
- * semaphore between RCS and VCS2 is initialized as INVALID.
- * Gen8 will initialize the sema between VCS2 and RCS later.
- */
- ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_RV;
- ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_RB;
- ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_RVE;
- ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.signal[RCS] = GEN6_NOSYNC;
- ring->semaphore.mbox.signal[VCS] = GEN6_VRSYNC;
- ring->semaphore.mbox.signal[BCS] = GEN6_BRSYNC;
- ring->semaphore.mbox.signal[VECS] = GEN6_VERSYNC;
- ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ if (i915_semaphore_is_enabled(dev)) {
+ ring->semaphore.sync_to = gen6_ring_sync;
+ ring->semaphore.signal = gen6_signal;
+ /*
+ * The current semaphore is only applied on pre-gen8
+ * platform. And there is no VCS2 ring on the pre-gen8
+ * platform. So the semaphore between RCS and VCS2 is
+ * initialized as INVALID. Gen8 will initialize the
+ * sema between VCS2 and RCS later.
+ */
+ ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_RV;
+ ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_RB;
+ ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_RVE;
+ ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.signal[RCS] = GEN6_NOSYNC;
+ ring->semaphore.mbox.signal[VCS] = GEN6_VRSYNC;
+ ring->semaphore.mbox.signal[BCS] = GEN6_BRSYNC;
+ ring->semaphore.mbox.signal[VECS] = GEN6_VERSYNC;
+ ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ }
} else if (IS_GEN5(dev)) {
ring->add_request = pc_render_add_request;
ring->flush = gen4_render_ring_flush;
@@ -2113,24 +2113,27 @@ int intel_init_bsd_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;
- /*
- * The current semaphore is only applied on pre-gen8 platform.
- * And there is no VCS2 ring on the pre-gen8 platform. So the
- * semaphore between VCS and VCS2 is initialized as INVALID.
- * Gen8 will initialize the sema between VCS2 and VCS later.
- */
- ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_VR;
- ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_VB;
- ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_VVE;
- ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.signal[RCS] = GEN6_RVSYNC;
- ring->semaphore.mbox.signal[VCS] = GEN6_NOSYNC;
- ring->semaphore.mbox.signal[BCS] = GEN6_BVSYNC;
- ring->semaphore.mbox.signal[VECS] = GEN6_VEVSYNC;
- ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ if (i915_semaphore_is_enabled(dev)) {
+ ring->semaphore.sync_to = gen6_ring_sync;
+ ring->semaphore.signal = gen6_signal;
+ /*
+ * The current semaphore is only applied on pre-gen8
+ * platform. And there is no VCS2 ring on the pre-gen8
+ * platform. So the semaphore between VCS and VCS2 is
+ * initialized as INVALID. Gen8 will initialize the
+ * sema between VCS2 and VCS later.
+ */
+ ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_VR;
+ ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_VB;
+ ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_VVE;
+ ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.signal[RCS] = GEN6_RVSYNC;
+ ring->semaphore.mbox.signal[VCS] = GEN6_NOSYNC;
+ ring->semaphore.mbox.signal[BCS] = GEN6_BVSYNC;
+ ring->semaphore.mbox.signal[VECS] = GEN6_VEVSYNC;
+ ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ }
} else {
ring->mmio_base = BSD_RING_BASE;
ring->flush = bsd_ring_flush;
@@ -2231,24 +2234,26 @@ int intel_init_blt_ring_buffer(struct drm_device *dev)
ring->irq_put = gen6_ring_put_irq;
ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
}
- ring->semaphore.sync_to = gen6_ring_sync;
- ring->semaphore.signal = gen6_signal;
- /*
- * The current semaphore is only applied on pre-gen8 platform. And
- * there is no VCS2 ring on the pre-gen8 platform. So the semaphore
- * between BCS and VCS2 is initialized as INVALID.
- * Gen8 will initialize the sema between BCS and VCS2 later.
- */
- ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_BR;
- ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_BV;
- ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_BVE;
- ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.signal[RCS] = GEN6_RBSYNC;
- ring->semaphore.mbox.signal[VCS] = GEN6_VBSYNC;
- ring->semaphore.mbox.signal[BCS] = GEN6_NOSYNC;
- ring->semaphore.mbox.signal[VECS] = GEN6_VEBSYNC;
- ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ if (i915_semaphore_is_enabled(dev)) {
+ ring->semaphore.signal = gen6_signal;
+ ring->semaphore.sync_to = gen6_ring_sync;
+ /*
+ * The current semaphore is only applied on pre-gen8 platform.
+ * And there is no VCS2 ring on the pre-gen8 platform. So the
+ * semaphore between BCS and VCS2 is initialized as INVALID.
+ * Gen8 will initialize the sema between BCS and VCS2 later.
+ */
+ ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_BR;
+ ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_BV;
+ ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_BVE;
+ ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.signal[RCS] = GEN6_RBSYNC;
+ ring->semaphore.mbox.signal[VCS] = GEN6_VBSYNC;
+ ring->semaphore.mbox.signal[BCS] = GEN6_NOSYNC;
+ ring->semaphore.mbox.signal[VECS] = GEN6_VEBSYNC;
+ ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ }
ring->init = init_ring_common;
return intel_init_ring_buffer(dev, ring);
@@ -2281,18 +2286,20 @@ int intel_init_vebox_ring_buffer(struct drm_device *dev)
ring->irq_put = hsw_vebox_put_irq;
ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
}
- ring->semaphore.sync_to = gen6_ring_sync;
- ring->semaphore.signal = gen6_signal;
- ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_VER;
- ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_VEV;
- ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_VEB;
- ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore.mbox.signal[RCS] = GEN6_RVESYNC;
- ring->semaphore.mbox.signal[VCS] = GEN6_VVESYNC;
- ring->semaphore.mbox.signal[BCS] = GEN6_BVESYNC;
- ring->semaphore.mbox.signal[VECS] = GEN6_NOSYNC;
- ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ if (i915_semaphore_is_enabled(dev)) {
+ ring->semaphore.sync_to = gen6_ring_sync;
+ ring->semaphore.signal = gen6_signal;
+ ring->semaphore.mbox.wait[RCS] = MI_SEMAPHORE_SYNC_VER;
+ ring->semaphore.mbox.wait[VCS] = MI_SEMAPHORE_SYNC_VEV;
+ ring->semaphore.mbox.wait[BCS] = MI_SEMAPHORE_SYNC_VEB;
+ ring->semaphore.mbox.wait[VECS] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.wait[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
+ ring->semaphore.mbox.signal[RCS] = GEN6_RVESYNC;
+ ring->semaphore.mbox.signal[VCS] = GEN6_VVESYNC;
+ ring->semaphore.mbox.signal[BCS] = GEN6_BVESYNC;
+ ring->semaphore.mbox.signal[VECS] = GEN6_NOSYNC;
+ ring->semaphore.mbox.signal[VCS2] = GEN6_NOSYNC;
+ }
ring->init = init_ring_common;
return intel_init_ring_buffer(dev, ring);
--
1.9.2
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