[PATCH 01/18] drm/i915: Comments for semaphore clarification

Ben Widawsky
2012-11-06T16:25:32Z

Semaphores are tied very closely to the rings in the GPU. Trivial patch
adds comments to the existing code so that when we add new rings we can
include comments there as well. It also helps distinguish the ring to
semaphore mailbox interactions by using the ringname in the semaphore
data structures.

This patch should have no functional impact.

A subset of this patch was:
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
drivers/gpu/drm/i915/i915_reg.h | 12 ++++++------
drivers/gpu/drm/i915/intel_ringbuffer.c | 18 +++++++++---------
drivers/gpu/drm/i915/intel_ringbuffer.h | 2 +-
3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9118bd1..f82755e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -252,12 +252,12 @@
#define MI_SEMAPHORE_UPDATE (1<<21)
#define MI_SEMAPHORE_COMPARE (1<<20)
#define MI_SEMAPHORE_REGISTER (1<<18)
-#define MI_SEMAPHORE_SYNC_RV (2<<16)
-#define MI_SEMAPHORE_SYNC_RB (0<<16)
-#define MI_SEMAPHORE_SYNC_VR (0<<16)
-#define MI_SEMAPHORE_SYNC_VB (2<<16)
-#define MI_SEMAPHORE_SYNC_BR (2<<16)
-#define MI_SEMAPHORE_SYNC_BV (0<<16)
+#define MI_SEMAPHORE_SYNC_RB (0<<16) /* RCS wait for BCS (BRSYNC) */
+#define MI_SEMAPHORE_SYNC_RV (2<<16) /* RCS wait for VCS (VRSYNC) */
+#define MI_SEMAPHORE_SYNC_VR (0<<16) /* VCS wait for RCS (RVSYNC) */
+#define MI_SEMAPHORE_SYNC_VB (2<<16) /* VCS wait for BCS (BVSYNC) */
+#define MI_SEMAPHORE_SYNC_BV (0<<16) /* BCS wait for VCS (VBSYNC) */
+#define MI_SEMAPHORE_SYNC_BR (2<<16) /* BCS wait for RCS (RBSYNC) */
#define MI_SEMAPHORE_SYNC_INVALID (1<<0)
/*
* 3D instructions used by the kernel
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index a035ac2..423948f 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1503,9 +1503,9 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
ring->irq_enable_mask = GT_USER_INTERRUPT;
ring->get_seqno = gen6_ring_get_seqno;
ring->sync_to = gen6_ring_sync;
- ring->semaphore_register[0] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore_register[1] = MI_SEMAPHORE_SYNC_RV;
- ring->semaphore_register[2] = MI_SEMAPHORE_SYNC_RB;
+ 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;
} else if (IS_GEN5(dev)) {
@@ -1639,9 +1639,9 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
ring->irq_put = gen6_ring_put_irq;
ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
ring->sync_to = gen6_ring_sync;
- ring->semaphore_register[0] = MI_SEMAPHORE_SYNC_VR;
- ring->semaphore_register[1] = MI_SEMAPHORE_SYNC_INVALID;
- ring->semaphore_register[2] = MI_SEMAPHORE_SYNC_VB;
+ 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;
} else {
@@ -1684,9 +1684,9 @@ 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->sync_to = gen6_ring_sync;
- ring->semaphore_register[0] = MI_SEMAPHORE_SYNC_BR;
- ring->semaphore_register[1] = MI_SEMAPHORE_SYNC_BV;
- ring->semaphore_register[2] = MI_SEMAPHORE_SYNC_INVALID;
+ 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->init = init_ring_common;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 5af65b8..df1a0a2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -89,7 +89,7 @@ struct intel_ring_buffer {
struct intel_ring_buffer *to,
u32 seqno);

- u32 semaphore_register[3]; /*our mbox written by others */
+ u32 semaphore_register[I915_NUM_RINGS]; /*our mbox written by others */
u32 signal_mbox[2]; /* mboxes this ring signals to */
/**
* List of objects currently involved in rendering from the
--
1.8.0