[Intel-gfx] [PATCH] drm/i915/vlv: Added/removed Render specific Hw Workarounds for VLV
Jani Nikula
jani.nikula at linux.intel.com
Thu Jan 9 13:26:28 CET 2014
On Thu, 09 Jan 2014, akash.goel at intel.com wrote:
> 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)
Frankly, I don't know much about these particular workarounds, but for
bisecting any regressions it would probably be a good idea to split the
patch per workaround touched.
BR,
Jani.
>
> 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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--
Jani Nikula, Intel Open Source Technology Center
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