[Intel-gfx] [PATCH] drm/i915/vlv: Added/removed Render specific Hw Workarounds for VLV

akash.goel at intel.com akash.goel at intel.com
Thu Jan 9 12:51:49 CET 2014


From: akashgoe <akash.goel at intel.com>

The following changes leads to stable behavior, especially
when playing 3D Apps, benchmarks.

Added 4 new rendering specific Workarounds
1. WaTlbInvalidateStoreDataBefore :-
     Before pipecontrol with TLB invalidate set,
     need 2 store data commands
2. WaReadAfterWriteHazard :-
     Send 8 store dword commands after flush
     for read after write hazard
     (HSD Gen6 bug_de 3047871)
3. WaVSThreadDispatchOverride
     Performance optimization - Hw will
     decide which half slice the thread
     will dispatch, May not be really needed
     for VLV, as its single slice
4. WaDisable_RenderCache_OperationalFlush
     Operational flush cannot be enabled on
     BWG A0 [Errata BWT006]

Removed 3 workarounds as not needed for VLV+(B0 onwards)
1. WaDisableRHWOOptimizationForRenderHang
2. WaDisableL3CacheAging
3. WaDisableDopClockGating

Modified the implementation of 1 workaround
1. WaDisableL3Bank2xClockGate
    Disabling L3 clock gating- MMIO 940c[25] = 1

Modified the programming of 2 registers in render ring init function
1. GFX_MODE_GEN7 (Enabling TLB invalidate)
2. MI_MODE (Enabling MI Flush)

Change-Id: Ib60f8dc7d2213552e498d588e1bba7eaa1a921ed
Signed-off-by: akashgoe <akash.goel at intel.com>
Signed-off-by: Akash Goel <akash.goel at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h         |  3 ++
 drivers/gpu/drm/i915/intel_pm.c         | 32 +++++++++++-------
 drivers/gpu/drm/i915/intel_ringbuffer.c | 58 ++++++++++++++++++++++++++++++---
 3 files changed, 77 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a699efd..d829754 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -934,6 +934,9 @@
 #define   ECO_GATING_CX_ONLY	(1<<3)
 #define   ECO_FLIP_DONE		(1<<0)
 
+#define GEN7_CACHE_MODE_0	0x07000 /* IVB+ only */
+#define GEN7_RC_OP_FLUSH_ENABLE (1<<0)
+
 #define CACHE_MODE_1		0x7004 /* IVB+ */
 #define   PIXEL_SUBSPAN_COLLECT_OPT_DISABLE (1<<6)
 
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 469170c..e4d220c 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4947,22 +4947,18 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 		   _MASKED_BIT_ENABLE(GEN7_MAX_PS_THREAD_DEP |
 				      GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE));
 
-	/* Apply the WaDisableRHWOOptimizationForRenderHang:vlv workaround. */
-	I915_WRITE(GEN7_COMMON_SLICE_CHICKEN1,
-		   GEN7_CSC1_RHWO_OPT_DISABLE_IN_RCC);
-
-	/* WaApplyL3ControlAndL3ChickenMode:vlv */
-	I915_WRITE(GEN7_L3CNTLREG1, I915_READ(GEN7_L3CNTLREG1) | GEN7_L3AGDIS);
 	I915_WRITE(GEN7_L3_CHICKEN_MODE_REGISTER, GEN7_WA_L3_CHICKEN_MODE);
 
+	/* WaDisable_RenderCache_OperationalFlush
+	 * Clear bit 0, so we do a AND with the mask
+	 * to keep other bits the same */
+	I915_WRITE(GEN7_CACHE_MODE_0,  (I915_READ(GEN7_CACHE_MODE_0) |
+			  _MASKED_BIT_DISABLE(GEN7_RC_OP_FLUSH_ENABLE)));
+
 	/* WaForceL3Serialization:vlv */
 	I915_WRITE(GEN7_L3SQCREG4, I915_READ(GEN7_L3SQCREG4) &
 		   ~L3SQ_URB_READ_CAM_MATCH_DISABLE);
 
-	/* WaDisableDopClockGating:vlv */
-	I915_WRITE(GEN7_ROW_CHICKEN2,
-		   _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
-
 	/* This is required by WaCatErrorRejectionIssue:vlv */
 	I915_WRITE(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG,
 		   I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) |
@@ -4991,10 +4987,24 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 		   GEN6_RCPBUNIT_CLOCK_GATE_DISABLE |
 		   GEN6_RCCUNIT_CLOCK_GATE_DISABLE);
 
-	I915_WRITE(GEN7_UCGCTL4, GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
+	/* WaDisableL3Bank2xClockGate
+	 * Disabling L3 clock gating- MMIO 940c[25] = 1
+	 * Set bit 25, to disable L3_BANK_2x_CLK_GATING */
+	I915_WRITE(GEN7_UCGCTL4,
+		I915_READ(GEN7_UCGCTL4) | GEN7_L3BANK2X_CLOCK_GATE_DISABLE);
 
 	I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE);
 
+	/* WaVSThreadDispatchOverride
+	 * Hw will decide which half slice the thread will dispatch.
+	 * May not be needed for VLV, as its a single slice */
+	I915_WRITE(GEN7_CACHE_MODE_0,
+		I915_READ(GEN7_FF_THREAD_MODE) &
+		(~GEN7_FF_VS_SCHED_LOAD_BALANCE));
+
+	/* WaDisable4x2SubspanOptimization,
+	 * Disable combining of two 2x2 subspans into a 4x2 subspan
+	 * Set chicken bit to disable subspan optimization */
 	I915_WRITE(CACHE_MODE_1,
 		   _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 442c9a6..c9350a1 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -563,7 +563,9 @@ static int init_render_ring(struct intel_ring_buffer *ring)
 	int ret = init_ring_common(ring);
 
 	if (INTEL_INFO(dev)->gen > 3)
-		I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
+		if (!IS_VALLEYVIEW(dev))
+			I915_WRITE(MI_MODE,
+				_MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
 
 	/* We need to disable the AsyncFlip performance optimisations in order
 	 * to use MI_WAIT_FOR_EVENT within the CS. It should already be
@@ -579,10 +581,17 @@ static int init_render_ring(struct intel_ring_buffer *ring)
 		I915_WRITE(GFX_MODE,
 			   _MASKED_BIT_ENABLE(GFX_TLB_INVALIDATE_ALWAYS));
 
-	if (IS_GEN7(dev))
-		I915_WRITE(GFX_MODE_GEN7,
-			   _MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
-			   _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
+	if (IS_GEN7(dev)) {
+		if (IS_VALLEYVIEW(dev)) {
+			I915_WRITE(GFX_MODE_GEN7,
+				_MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
+			I915_WRITE(MI_MODE, I915_READ(MI_MODE) |
+				_MASKED_BIT_ENABLE(MI_FLUSH_ENABLE));
+		} else
+			I915_WRITE(GFX_MODE_GEN7,
+				_MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
+				_MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
+	}
 
 	if (INTEL_INFO(dev)->gen >= 5) {
 		ret = init_pipe_control(ring);
@@ -2157,6 +2166,7 @@ int
 intel_ring_flush_all_caches(struct intel_ring_buffer *ring)
 {
 	int ret;
+	int i;
 
 	if (!ring->gpu_caches_dirty)
 		return 0;
@@ -2165,6 +2175,26 @@ intel_ring_flush_all_caches(struct intel_ring_buffer *ring)
 	if (ret)
 		return ret;
 
+	/* WaReadAfterWriteHazard*/
+	/* Send a number of Store Data commands here to finish
+	   flushing hardware pipeline.This is needed in the case
+	   where the next workload tries reading from the same
+	   surface that this batch writes to. Without these StoreDWs,
+	   not all of the data will actually be flushd to the surface
+	   by the time the next batch starts reading it, possibly
+	   causing a small amount of corruption.*/
+	ret = intel_ring_begin(ring, 4 * 12);
+	if (ret)
+		return ret;
+	for (i = 0; i < 12; i++) {
+		intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
+		intel_ring_emit(ring, I915_GEM_HWS_SCRATCH_INDEX <<
+						MI_STORE_DWORD_INDEX_SHIFT);
+		intel_ring_emit(ring, 0);
+		intel_ring_emit(ring, MI_NOOP);
+	}
+	intel_ring_advance(ring);
+
 	trace_i915_gem_ring_flush(ring, 0, I915_GEM_GPU_DOMAINS);
 
 	ring->gpu_caches_dirty = false;
@@ -2176,6 +2206,24 @@ intel_ring_invalidate_all_caches(struct intel_ring_buffer *ring)
 {
 	uint32_t flush_domains;
 	int ret;
+	int i;
+
+	/* WaTlbInvalidateStoreDataBefore*/
+	/* Before pipecontrol with TLB invalidate set, need 2 store
+	   data commands (such as MI_STORE_DATA_IMM or MI_STORE_DATA_INDEX)
+	   Without this, hardware cannot guarantee the command after the
+	   PIPE_CONTROL with TLB inv will not use the old TLB values.*/
+	ret = intel_ring_begin(ring, 4 * 2);
+	if (ret)
+		return ret;
+	for (i = 0; i < 2; i++) {
+		intel_ring_emit(ring, MI_STORE_DWORD_INDEX);
+		intel_ring_emit(ring, I915_GEM_HWS_SCRATCH_INDEX <<
+						MI_STORE_DWORD_INDEX_SHIFT);
+		intel_ring_emit(ring, 0);
+		intel_ring_emit(ring, MI_NOOP);
+	}
+	intel_ring_advance(ring);
 
 	flush_domains = 0;
 	if (ring->gpu_caches_dirty)
-- 
1.8.5.2




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