[PATCH 02/18] drm/i915: Semaphore MBOX update generalization

Ben Widawsky
2012-11-06T16:25:37Z

This replaces the existing MBOX update code with a more generalized
calculation for emitting mbox updates. We also create a sentinel for
doing the updates so we can more abstractly deal with the rings.

When doing MBOX updates the code must be aware of the /other/ rings.
Until now the platforms which supported semaphores had a fixed number of
rings and so it made sense for the code to be very specialized
(hardcoded).

The patch does contain a functional change, but should have no
behavioral changes.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
drivers/gpu/drm/i915/i915_reg.h | 1 +
drivers/gpu/drm/i915/intel_ringbuffer.c | 40 ++++++++++++++++++++-------------
drivers/gpu/drm/i915/intel_ringbuffer.h | 2 +-
3 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f82755e..d220410 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -438,6 +438,7 @@
#define GEN6_VRSYNC (RING_SYNC_1(GEN6_BSD_RING_BASE))
#define GEN6_VBSYNC (RING_SYNC_0(GEN6_BSD_RING_BASE))
#define GEN6_BRSYNC (RING_SYNC_0(BLT_RING_BASE))
+#define GEN6_NOSYNC 0
#define GEN6_BVSYNC (RING_SYNC_1(BLT_RING_BASE))
#define RING_MAX_IDLE(base) ((base)+0x54)
#define RING_HWS_PGA(base) ((base)+0x80)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 423948f..ace1176 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -558,12 +558,14 @@ update_mboxes(struct intel_ring_buffer *ring,
u32 seqno,
u32 mmio_offset)
{
+#define MBOX_UPDATE_DWORDS 4
intel_ring_emit(ring, MI_SEMAPHORE_MBOX |
MI_SEMAPHORE_GLOBAL_GTT |
MI_SEMAPHORE_REGISTER |
MI_SEMAPHORE_UPDATE);
intel_ring_emit(ring, seqno);
intel_ring_emit(ring, mmio_offset);
+ intel_ring_emit(ring, MI_NOOP);
}

/**
@@ -579,21 +581,26 @@ static int
gen6_add_request(struct intel_ring_buffer *ring,
u32 *seqno)
{
- u32 mbox1_reg;
- u32 mbox2_reg;
- int ret;
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_ring_buffer *useless;
+ int i, ret;

- ret = intel_ring_begin(ring, 10);
+ ret = intel_ring_begin(ring, ((I915_NUM_RINGS-1) *
+ MBOX_UPDATE_DWORDS) +
+ 4);
if (ret)
return ret;
-
- mbox1_reg = ring->signal_mbox[0];
- mbox2_reg = ring->signal_mbox[1];
+#undef MBOX_UPDATE_DWORDS

*seqno = i915_gem_next_request_seqno(ring);

- update_mboxes(ring, *seqno, mbox1_reg);
- update_mboxes(ring, *seqno, mbox2_reg);
+ for_each_ring(useless, dev_priv, i) {
+ u32 mbox_reg = ring->signal_mbox[i];
+ if (mbox_reg != GEN6_NOSYNC)
+ update_mboxes(ring, *seqno, mbox_reg);
+ }
+
intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
intel_ring_emit(ring, I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
intel_ring_emit(ring, *seqno);
@@ -1506,8 +1513,9 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_INVALID;
ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_RV;
ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_RB;
- ring->signal_mbox[0] = GEN6_VRSYNC;
- ring->signal_mbox[1] = GEN6_BRSYNC;
+ ring->signal_mbox[RCS] = GEN6_NOSYNC;
+ ring->signal_mbox[VCS] = GEN6_VRSYNC;
+ ring->signal_mbox[BCS] = GEN6_BRSYNC;
} else if (IS_GEN5(dev)) {
ring->add_request = pc_render_add_request;
ring->flush = gen4_render_ring_flush;
@@ -1642,8 +1650,9 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_VR;
ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_INVALID;
ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_VB;
- ring->signal_mbox[0] = GEN6_RVSYNC;
- ring->signal_mbox[1] = GEN6_BVSYNC;
+ ring->signal_mbox[RCS] = GEN6_RVSYNC;
+ ring->signal_mbox[VCS] = GEN6_NOSYNC;
+ ring->signal_mbox[BCS] = GEN6_BVSYNC;
} else {
ring->mmio_base = BSD_RING_BASE;
ring->flush = bsd_ring_flush;
@@ -1687,8 +1696,9 @@ int intel_init_blt_ring_buffer(struct drm_device *dev)
ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_BR;
ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_BV;
ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_INVALID;
- ring->signal_mbox[0] = GEN6_RBSYNC;
- ring->signal_mbox[1] = GEN6_VBSYNC;
+ ring->signal_mbox[RCS] = GEN6_RBSYNC;
+ ring->signal_mbox[VCS] = GEN6_VBSYNC;
+ ring->signal_mbox[BCS] = GEN6_NOSYNC;
ring->init = init_ring_common;

return intel_init_ring_buffer(dev, ring);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index df1a0a2..d8eecb1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -90,7 +90,7 @@ struct intel_ring_buffer {
u32 seqno);

u32 semaphore_register[I915_NUM_RINGS]; /*our mbox written by others */
- u32 signal_mbox[2]; /* mboxes this ring signals to */
+ u32 signal_mbox[I915_NUM_RINGS]; /* mboxes this ring signals to */
/**
* List of objects currently involved in rendering from the
* ringbuffer.
--
1.8.0