[Intel-gfx] [PATCH 1/2 v2] drm/i915: Dumb down the semaphore logic
Ben Widawsky
ben at bwidawsk.net
Wed Sep 14 04:17:56 CEST 2011
While I think the previous code is correct, it was hard to follow and
hard to debug. Since we already have a ring abstraction, might as well
use it to handle the semaphore updates and compares.
I don't expect this code to make semaphores better or worse, but you
never know...
v2: Noting special
* Took Keith's suggestions in.
* Tried to take Daniel's suggestion in, but the change got too intrusive for
* this supposedly simple cleanup
* Ran Daniel's gem_ring_sync_loop test on this
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Keith Packard <keithp at keithp.com>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 +-
drivers/gpu/drm/i915/i915_reg.h | 13 ++
drivers/gpu/drm/i915/intel_ringbuffer.c | 171 +++++++++++++++++++++-------
drivers/gpu/drm/i915/intel_ringbuffer.h | 7 +-
4 files changed, 148 insertions(+), 46 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 4934cf8..3693e83 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -784,7 +784,8 @@ i915_gem_execbuffer_sync_rings(struct drm_i915_gem_object *obj,
}
from->sync_seqno[idx] = seqno;
- return intel_ring_sync(to, from, seqno - 1);
+
+ return to->sync_to(to, from, seqno - 1);
}
static int
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 542453f..6a92364 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -194,6 +194,13 @@
#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_INVALID (1<<0)
/*
* 3D instructions used by the kernel
*/
@@ -296,6 +303,12 @@
#define RING_CTL(base) ((base)+0x3c)
#define RING_SYNC_0(base) ((base)+0x40)
#define RING_SYNC_1(base) ((base)+0x44)
+#define RVSYNC (RING_SYNC_0(dev_priv->ring[RCS].mmio_base))
+#define RBSYNC (RING_SYNC_1(dev_priv->ring[RCS].mmio_base))
+#define VRSYNC (RING_SYNC_1(dev_priv->ring[VCS].mmio_base))
+#define VBSYNC (RING_SYNC_0(dev_priv->ring[VCS].mmio_base))
+#define BRSYNC (RING_SYNC_0(dev_priv->ring[BCS].mmio_base))
+#define BVSYNC (RING_SYNC_1(dev_priv->ring[BCS].mmio_base))
#define RING_MAX_IDLE(base) ((base)+0x54)
#define RING_HWS_PGA(base) ((base)+0x80)
#define RING_HWS_PGA_GEN6(base) ((base)+0x2080)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index c30626e..3bac2d5 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -315,33 +315,32 @@ static void render_ring_cleanup(struct intel_ring_buffer *ring)
}
static void
-update_semaphore(struct intel_ring_buffer *ring, int i, u32 seqno)
+update_mboxes(struct intel_ring_buffer *ring,
+ u32 seqno,
+ u32 mmio_offset)
{
- struct drm_device *dev = ring->dev;
- struct drm_i915_private *dev_priv = dev->dev_private;
- int id;
-
- /*
- * cs -> 1 = vcs, 0 = bcs
- * vcs -> 1 = bcs, 0 = cs,
- * bcs -> 1 = cs, 0 = vcs.
- */
- id = ring - dev_priv->ring;
- id += 2 - i;
- id %= 3;
-
- intel_ring_emit(ring,
- MI_SEMAPHORE_MBOX |
- MI_SEMAPHORE_REGISTER |
- MI_SEMAPHORE_UPDATE);
+ 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,
- RING_SYNC_0(dev_priv->ring[id].mmio_base) + 4*i);
+ intel_ring_emit(ring, mmio_offset);
}
-static int
+/**
+ * gen6_add_request - Update the semaphore mailbox registers
+ *
+ * @ring - ring that is adding a request
+ * @mbox1_reg - mailbox address for RCS or VCS ring
+ * @mbox2_reg - mailbox address for VCS or BCS ring
+ *
+ * Update the mailbox registers in the *other* rings with the current seqno.
+ * This acts like a signal in the canonical semaphore.
+ */
+static u32
gen6_add_request(struct intel_ring_buffer *ring,
- u32 *result)
+ u32 mbox1_reg,
+ u32 mbox2_reg)
{
u32 seqno;
int ret;
@@ -351,43 +350,119 @@ gen6_add_request(struct intel_ring_buffer *ring,
return ret;
seqno = i915_gem_get_seqno(ring->dev);
- update_semaphore(ring, 0, seqno);
- update_semaphore(ring, 1, seqno);
+ update_mboxes(ring, seqno, mbox1_reg);
+ update_mboxes(ring, seqno, mbox2_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);
intel_ring_emit(ring, MI_USER_INTERRUPT);
intel_ring_advance(ring);
- *result = seqno;
+ return seqno;
+}
+
+static int
+gen6_blt_add_request(struct intel_ring_buffer *ring,
+ u32 *result)
+{
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ *result = gen6_add_request(ring,
+ RBSYNC, /* render->blitter sync */
+ VBSYNC); /* video->blitter sync */
return 0;
}
-int
-intel_ring_sync(struct intel_ring_buffer *ring,
- struct intel_ring_buffer *to,
+static int
+gen6_bsd_add_request(struct intel_ring_buffer *ring,
+ u32 *result)
+{
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ *result = gen6_add_request(ring,
+ RVSYNC, /* video->render sync */
+ BVSYNC); /* video->blitter sync */
+ return 0;
+}
+
+static int
+gen6_render_add_request(struct intel_ring_buffer *ring,
+ u32 *result)
+{
+ struct drm_device *dev = ring->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ *result = gen6_add_request(ring,
+ VRSYNC, /* render->video sync */
+ BRSYNC); /* render->blitter sync */
+ return 0;
+}
+
+static int
+intel_ring_sync(struct intel_ring_buffer *waiter,
+ struct intel_ring_buffer *signaller,
+ int ring,
u32 seqno)
{
int ret;
+ u32 temp = MI_SEMAPHORE_MBOX |
+ MI_SEMAPHORE_COMPARE |
+ MI_SEMAPHORE_REGISTER;
- ret = intel_ring_begin(ring, 4);
+ ret = intel_ring_begin(waiter, 4);
if (ret)
return ret;
- intel_ring_emit(ring,
- MI_SEMAPHORE_MBOX |
- MI_SEMAPHORE_REGISTER |
- intel_ring_sync_index(ring, to) << 17 |
- MI_SEMAPHORE_COMPARE);
- intel_ring_emit(ring, seqno);
- intel_ring_emit(ring, 0);
- intel_ring_emit(ring, MI_NOOP);
- intel_ring_advance(ring);
+ intel_ring_emit(waiter, temp | signaller->semaphore_register[ring]);
+ intel_ring_emit(waiter, seqno);
+ intel_ring_emit(waiter, 0);
+ intel_ring_emit(waiter, MI_NOOP);
+ intel_ring_advance(waiter);
return 0;
}
+/* VCS->RCS (RVSYNC) or BCS->RCS (RBSYNC) */
+int
+render_ring_sync_to(struct intel_ring_buffer *waiter,
+ struct intel_ring_buffer *signaller,
+ u32 seqno)
+{
+ WARN_ON(signaller->semaphore_register[RCS] == MI_SEMAPHORE_SYNC_INVALID);
+ return intel_ring_sync(waiter,
+ signaller,
+ RCS,
+ seqno);
+}
+
+/* RCS->VCS (VRSYNC) or BCS->VCS (VBSYNC) */
+int
+gen6_bsd_ring_sync_to(struct intel_ring_buffer *waiter,
+ struct intel_ring_buffer *signaller,
+ u32 seqno)
+{
+ WARN_ON(signaller->semaphore_register[VCS] == MI_SEMAPHORE_SYNC_INVALID);
+ return intel_ring_sync(waiter,
+ signaller,
+ VCS,
+ seqno);
+}
+
+/* RCS->BCS (BRSYNC) or VCS->BCS (BVSYNC) */
+int
+gen6_blt_ring_sync_to(struct intel_ring_buffer *waiter,
+ struct intel_ring_buffer *signaller,
+ u32 seqno)
+{
+ WARN_ON(signaller->semaphore_register[BCS] == MI_SEMAPHORE_SYNC_INVALID);
+ return intel_ring_sync(waiter,
+ signaller,
+ BCS,
+ seqno);
+}
+
+
+
#define PIPE_CONTROL_FLUSH(ring__, addr__) \
do { \
intel_ring_emit(ring__, GFX_OP_PIPE_CONTROL | PIPE_CONTROL_QW_WRITE | \
@@ -1027,6 +1102,10 @@ static const struct intel_ring_buffer render_ring = {
.irq_put = render_ring_put_irq,
.dispatch_execbuffer = render_ring_dispatch_execbuffer,
.cleanup = render_ring_cleanup,
+ .sync_to = render_ring_sync_to,
+ .semaphore_register = {MI_SEMAPHORE_SYNC_INVALID,
+ MI_SEMAPHORE_SYNC_RV,
+ MI_SEMAPHORE_SYNC_RB},
};
/* ring buffer for bit-stream decoder */
@@ -1149,11 +1228,15 @@ static const struct intel_ring_buffer gen6_bsd_ring = {
.init = init_ring_common,
.write_tail = gen6_bsd_ring_write_tail,
.flush = gen6_ring_flush,
- .add_request = gen6_add_request,
+ .add_request = gen6_bsd_add_request,
.get_seqno = ring_get_seqno,
.irq_get = gen6_bsd_ring_get_irq,
.irq_put = gen6_bsd_ring_put_irq,
.dispatch_execbuffer = gen6_ring_dispatch_execbuffer,
+ .sync_to = gen6_bsd_ring_sync_to,
+ .semaphore_register = {MI_SEMAPHORE_SYNC_VR,
+ MI_SEMAPHORE_SYNC_INVALID,
+ MI_SEMAPHORE_SYNC_VB},
};
/* Blitter support (SandyBridge+) */
@@ -1279,12 +1362,16 @@ static const struct intel_ring_buffer gen6_blt_ring = {
.init = blt_ring_init,
.write_tail = ring_write_tail,
.flush = blt_ring_flush,
- .add_request = gen6_add_request,
+ .add_request = gen6_blt_add_request,
.get_seqno = ring_get_seqno,
.irq_get = blt_ring_get_irq,
.irq_put = blt_ring_put_irq,
.dispatch_execbuffer = gen6_ring_dispatch_execbuffer,
.cleanup = blt_ring_cleanup,
+ .sync_to = gen6_blt_ring_sync_to,
+ .semaphore_register = {MI_SEMAPHORE_SYNC_BR,
+ MI_SEMAPHORE_SYNC_BV,
+ MI_SEMAPHORE_SYNC_INVALID},
};
int intel_init_render_ring_buffer(struct drm_device *dev)
@@ -1294,7 +1381,7 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
*ring = render_ring;
if (INTEL_INFO(dev)->gen >= 6) {
- ring->add_request = gen6_add_request;
+ ring->add_request = gen6_render_add_request;
ring->irq_get = gen6_render_ring_get_irq;
ring->irq_put = gen6_render_ring_put_irq;
} else if (IS_GEN5(dev)) {
@@ -1317,7 +1404,7 @@ int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size)
*ring = render_ring;
if (INTEL_INFO(dev)->gen >= 6) {
- ring->add_request = gen6_add_request;
+ ring->add_request = gen6_render_add_request;
ring->irq_get = gen6_render_ring_get_irq;
ring->irq_put = gen6_render_ring_put_irq;
} else if (IS_GEN5(dev)) {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 39ac2b6..98052fd 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -75,7 +75,11 @@ struct intel_ring_buffer {
int (*dispatch_execbuffer)(struct intel_ring_buffer *ring,
u32 offset, u32 length);
void (*cleanup)(struct intel_ring_buffer *ring);
+ int (*sync_to)(struct intel_ring_buffer *ring,
+ struct intel_ring_buffer *to,
+ u32 seqno);
+ u32 semaphore_register[3];
/**
* List of objects currently involved in rendering from the
* ringbuffer.
@@ -180,9 +184,6 @@ static inline void intel_ring_emit(struct intel_ring_buffer *ring,
void intel_ring_advance(struct intel_ring_buffer *ring);
u32 intel_ring_get_seqno(struct intel_ring_buffer *ring);
-int intel_ring_sync(struct intel_ring_buffer *ring,
- struct intel_ring_buffer *to,
- u32 seqno);
int intel_init_render_ring_buffer(struct drm_device *dev);
int intel_init_bsd_ring_buffer(struct drm_device *dev);
--
1.7.6.1
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