From: Tvrtko Ursulin <tvrtko.ursu...@intel.com>

Static table wastes space for invalid combinations and
engines which are not supported by Gen6 (legacy semaphores).

Replace it with a function devised by Dave Gordon.

I have verified that it generates the same mappings between
mbox selectors and signalling registers.

v2: Add a comment describing what gen6_sem_f does.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
Cc: Dave Gordon <david.s.gor...@intel.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_reg.h         |  7 ++---
 drivers/gpu/drm/i915/intel_engine_cs.c  | 48 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_ringbuffer.c | 40 ++-------------------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  3 +++
 4 files changed, 57 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9397ddec26b9..c2fe718582c8 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1604,9 +1604,10 @@ enum skl_disp_power_wells {
 #define RING_HEAD(base)                _MMIO((base)+0x34)
 #define RING_START(base)       _MMIO((base)+0x38)
 #define RING_CTL(base)         _MMIO((base)+0x3c)
-#define RING_SYNC_0(base)      _MMIO((base)+0x40)
-#define RING_SYNC_1(base)      _MMIO((base)+0x44)
-#define RING_SYNC_2(base)      _MMIO((base)+0x48)
+#define RING_SYNC(base, n)     _MMIO((base) + 0x40 + (n) * 4)
+#define RING_SYNC_0(base)      RING_SYNC(base, 0)
+#define RING_SYNC_1(base)      RING_SYNC(base, 1)
+#define RING_SYNC_2(base)      RING_SYNC(base, 2)
 #define GEN6_RVSYNC    (RING_SYNC_0(RENDER_RING_BASE))
 #define GEN6_RBSYNC    (RING_SYNC_1(RENDER_RING_BASE))
 #define GEN6_RVESYNC   (RING_SYNC_2(RENDER_RING_BASE))
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c 
b/drivers/gpu/drm/i915/intel_engine_cs.c
index f4a35ec78481..9837fddae259 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -209,3 +209,51 @@ int intel_engine_init_common(struct intel_engine_cs 
*engine)
 
        return i915_cmd_parser_init_ring(engine);
 }
+
+#define I915_NUM_GEN6_SEMAPHORE_ENGINES (4)
+
+static int gen6_sem_f(unsigned int x, unsigned int y)
+{
+       if (x == y)
+               return -1;
+
+       x = intel_engines[x].guc_id;
+       y = intel_engines[y].guc_id;
+
+       if (x >= I915_NUM_GEN6_SEMAPHORE_ENGINES ||
+           y >= I915_NUM_GEN6_SEMAPHORE_ENGINES)
+               return -1;
+
+       x -= x >= y;
+       if (y == 1)
+               x = 3 - x;
+       x += y & 1;
+       return x % 3;
+}
+
+u32 gen6_wait_mbox(enum intel_engine_id x, enum intel_engine_id y)
+{
+       int r;
+
+       r = gen6_sem_f(x, y);
+       if (r < 0)
+               return MI_SEMAPHORE_SYNC_INVALID;
+
+       if (r == 1)
+               r = 2;
+       else if (r == 2)
+               r = 1;
+
+       return r << 16;
+}
+
+i915_reg_t gen6_signal_reg(enum intel_engine_id x, enum intel_engine_id y)
+{
+       int r;
+
+       r = gen6_sem_f(x, y);
+       if (r < 0)
+               return GEN6_NOSYNC;
+
+       return RING_SYNC(intel_engines[y].mmio_base, r);
+}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c 
b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 0b5d1de8a7fb..fabf8b6bcae6 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2745,44 +2745,8 @@ static void intel_ring_init_semaphores(struct 
drm_i915_private *dev_priv,
                 * sema between VCS2 and RCS later.
                 */
                for (i = 0; i < I915_NUM_ENGINES; i++) {
-                       static const struct {
-                               u32 wait_mbox;
-                               i915_reg_t mbox_reg;
-                       } sem_data[I915_NUM_ENGINES][I915_NUM_ENGINES] = {
-                               [RCS] = {
-                                       [VCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_RV,  .mbox_reg = GEN6_VRSYNC },
-                                       [BCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_RB,  .mbox_reg = GEN6_BRSYNC },
-                                       [VECS] = { .wait_mbox = 
MI_SEMAPHORE_SYNC_RVE, .mbox_reg = GEN6_VERSYNC },
-                               },
-                               [VCS] = {
-                                       [RCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_VR,  .mbox_reg = GEN6_RVSYNC },
-                                       [BCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_VB,  .mbox_reg = GEN6_BVSYNC },
-                                       [VECS] = { .wait_mbox = 
MI_SEMAPHORE_SYNC_VVE, .mbox_reg = GEN6_VEVSYNC },
-                               },
-                               [BCS] = {
-                                       [RCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_BR,  .mbox_reg = GEN6_RBSYNC },
-                                       [VCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_BV,  .mbox_reg = GEN6_VBSYNC },
-                                       [VECS] = { .wait_mbox = 
MI_SEMAPHORE_SYNC_BVE, .mbox_reg = GEN6_VEBSYNC },
-                               },
-                               [VECS] = {
-                                       [RCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_VER, .mbox_reg = GEN6_RVESYNC },
-                                       [VCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_VEV, .mbox_reg = GEN6_VVESYNC },
-                                       [BCS] =  { .wait_mbox = 
MI_SEMAPHORE_SYNC_VEB, .mbox_reg = GEN6_BVESYNC },
-                               },
-                       };
-                       u32 wait_mbox;
-                       i915_reg_t mbox_reg;
-
-                       if (i == engine->id || i == VCS2) {
-                               wait_mbox = MI_SEMAPHORE_SYNC_INVALID;
-                               mbox_reg = GEN6_NOSYNC;
-                       } else {
-                               wait_mbox = sem_data[engine->id][i].wait_mbox;
-                               mbox_reg = sem_data[engine->id][i].mbox_reg;
-                       }
-
-                       engine->semaphore.mbox.wait[i] = wait_mbox;
-                       engine->semaphore.mbox.signal[i] = mbox_reg;
+                       engine->semaphore.mbox.wait[i] = 
gen6_wait_mbox(engine->id, i);
+                       engine->semaphore.mbox.signal[i] = 
gen6_signal_reg(engine->id, i);
                }
        }
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h 
b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 0f8019488d33..cb3d22752b07 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -493,6 +493,9 @@ int intel_ring_invalidate_all_caches(struct 
drm_i915_gem_request *req);
 int intel_init_pipe_control(struct intel_engine_cs *engine, int size);
 void intel_fini_pipe_control(struct intel_engine_cs *engine);
 
+u32 gen6_wait_mbox(enum intel_engine_id x, enum intel_engine_id y);
+i915_reg_t gen6_signal_reg(enum intel_engine_id x, enum intel_engine_id y);
+
 void intel_engine_setup_common(struct intel_engine_cs *engine);
 int intel_engine_init_common(struct intel_engine_cs *engine);
 
-- 
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to