Re: [RFC] drm/i915/bdw: Initialize BDW workarounds in render ring init fn

Ville Syrjälä
2014-07-28T17:01:52Z

On Mon, Jul 28, 2014 at 05:31:46PM +0100, arun.siluvery@linux.intel.com wrote:
> From: Arun Siluvery <arun.siluvery@linux.intel.com>
>
> The workarounds at the moment are initialized in init_clock_gating() but
> they are lost during reset; In case of execlists some workarounds modify
> registers that are part of register state context, since these are not
> initialized until init_clock_gating() default context ends up with
> incorrect values as render context is restored and saved before updated
> by workarounds hence move them to render ring init fn. This should be
> ok as these workarounds are not related to display clock gating.
>
> Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 46 ++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_pm.c | 59 ----------------------------
> drivers/gpu/drm/i915/intel_ringbuffer.c | 68 +++++++++++++++++++++++++++++++++
> 3 files changed, 114 insertions(+), 59 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 083683c..cf7da30 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2397,20 +2397,65 @@ static int i915_shared_dplls_info(struct seq_file *m, void *unused)
> seq_printf(m, " dpll_md: 0x%08x\n", pll->hw_state.dpll_md);
> seq_printf(m, " fp0: 0x%08x\n", pll->hw_state.fp0);
> seq_printf(m, " fp1: 0x%08x\n", pll->hw_state.fp1);
> seq_printf(m, " wrpll: 0x%08x\n", pll->hw_state.wrpll);
> }
> drm_modeset_unlock_all(dev);
>
> return 0;
> }
>
> +static int i915_workaround_info(struct seq_file *m, void *unused)
> +{
> + struct drm_info_node *node = (struct drm_info_node *) m->private;
> + struct drm_device *dev = node->minor->dev;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + int ret;
> +
> + ret = mutex_lock_interruptible(&dev->struct_mutex);
> + if (ret)
> + return ret;
> +
> + if (IS_BROADWELL(dev)) {
> + seq_printf(m, "GEN8_ROW_CHICKEN:\t0x%08x\n",
> + I915_READ(GEN8_ROW_CHICKEN));
> + seq_printf(m, "HALF_SLICE_CHICKEN3:\t0x%08x\n",
> + I915_READ(HALF_SLICE_CHICKEN3));
> + seq_printf(m, "GAMTARBMODE:\t0x%08x\n", I915_READ(GAMTARBMODE));
> + seq_printf(m, "_3D_CHICKEN3:\t0x%08x\n",
> + I915_READ(_3D_CHICKEN3));
> + seq_printf(m, "COMMON_SLICE_CHICKEN2:\t0x%08x\n",
> + I915_READ(COMMON_SLICE_CHICKEN2));
> + seq_printf(m, "GEN7_HALF_SLICE_CHICKEN1:\t0x%08x\n",
> + I915_READ(GEN7_HALF_SLICE_CHICKEN1));
> + seq_printf(m, "GEN7_ROW_CHICKEN2:\t0x%08x\n",
> + I915_READ(GEN7_ROW_CHICKEN2));
> + seq_printf(m, "GAM_ECOCHK:\t0x%08x\n",
> + I915_READ(GAM_ECOCHK));
> + seq_printf(m, "HDC_CHICKEN0:\t0x%08x\n",
> + I915_READ(HDC_CHICKEN0));
> + seq_printf(m, "GEN7_FF_THREAD_MODE:\t0x%08x\n",
> + I915_READ(GEN7_FF_THREAD_MODE));
> + seq_printf(m, "GEN8_UCGCTL6:\t0x%08x\n",
> + I915_READ(GEN8_UCGCTL6));
> + seq_printf(m, "GEN6_RC_SLEEP_PSMI_CONTROL:\t0x%08x\n",
> + I915_READ(GEN6_RC_SLEEP_PSMI_CONTROL));
> + seq_printf(m, "CACHE_MODE_1:\t0x%08x\n",
> + I915_READ(CACHE_MODE_1));
> + } else
> + DRM_DEBUG_DRIVER("Not available for Gen%d\n",
> + INTEL_INFO(dev)->gen);
> +
> + mutex_unlock(&dev->struct_mutex);
> + return 0;
> +}
> +

This smells like a separate patch. But I'm not sure we want at all since
intel_reg_read will provide the same information.

> struct pipe_crc_info {
> const char *name;
> struct drm_device *dev;
> enum pipe pipe;
> };
>
> static int i915_pipe_crc_open(struct inode *inode, struct file *filep)
> {
> struct pipe_crc_info *info = inode->i_private;
> struct drm_i915_private *dev_priv = info->dev->dev_private;
> @@ -3904,20 +3949,21 @@ static const struct drm_info_list i915_debugfs_list[] = {
> {"i915_ppgtt_info", i915_ppgtt_info, 0},
> {"i915_llc", i915_llc, 0},
> {"i915_edp_psr_status", i915_edp_psr_status, 0},
> {"i915_sink_crc_eDP1", i915_sink_crc, 0},
> {"i915_energy_uJ", i915_energy_uJ, 0},
> {"i915_pc8_status", i915_pc8_status, 0},
> {"i915_power_domain_info", i915_power_domain_info, 0},
> {"i915_display_info", i915_display_info, 0},
> {"i915_semaphore_status", i915_semaphore_status, 0},
> {"i915_shared_dplls_info", i915_shared_dplls_info, 0},
> + {"i915_workaround_info", i915_workaround_info, 0},
> };
> #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
>
> static const struct i915_debugfs_files {
> const char *name;
> const struct file_operations *fops;
> } i915_debugfs_files[] = {
> {"i915_wedged", &i915_wedged_fops},
> {"i915_max_freq", &i915_max_freq_fops},
> {"i915_min_freq", &i915_min_freq_fops},
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 3f88f29..9597f95 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -5393,101 +5393,42 @@ static void gen8_init_clock_gating(struct drm_device *dev)
> struct drm_i915_private *dev_priv = dev->dev_private;
> enum pipe pipe;
>
> I915_WRITE(WM3_LP_ILK, 0);
> I915_WRITE(WM2_LP_ILK, 0);
> I915_WRITE(WM1_LP_ILK, 0);
>
> /* FIXME(BDW): Check all the w/a, some might only apply to
> * pre-production hw. */
>
> - /* WaDisablePartialInstShootdown:bdw */
> - I915_WRITE(GEN8_ROW_CHICKEN,
> - _MASKED_BIT_ENABLE(PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE));
> -
> - /* WaDisableThreadStallDopClockGating:bdw */
> - /* FIXME: Unclear whether we really need this on production bdw. */
> - I915_WRITE(GEN8_ROW_CHICKEN,
> - _MASKED_BIT_ENABLE(STALL_DOP_GATING_DISABLE));
> -
> - /*
> - * This GEN8_CENTROID_PIXEL_OPT_DIS W/A is only needed for
> - * pre-production hardware
> - */
> - I915_WRITE(HALF_SLICE_CHICKEN3,
> - _MASKED_BIT_ENABLE(GEN8_CENTROID_PIXEL_OPT_DIS));
> - I915_WRITE(HALF_SLICE_CHICKEN3,
> - _MASKED_BIT_ENABLE(GEN8_SAMPLER_POWER_BYPASS_DIS));
> - I915_WRITE(GAMTARBMODE, _MASKED_BIT_ENABLE(ARB_MODE_BWGTLB_DISABLE));
> -
> - I915_WRITE(_3D_CHICKEN3,
> - _MASKED_BIT_ENABLE(_3D_CHICKEN_SDE_LIMIT_FIFO_POLY_DEPTH(2)));
> -
> - I915_WRITE(COMMON_SLICE_CHICKEN2,
> - _MASKED_BIT_ENABLE(GEN8_CSC2_SBE_VUE_CACHE_CONSERVATIVE));
> -
> - I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
> - _MASKED_BIT_ENABLE(GEN7_SINGLE_SUBSCAN_DISPATCH_ENABLE));
> -
> - /* WaDisableDopClockGating:bdw May not be needed for production */
> - I915_WRITE(GEN7_ROW_CHICKEN2,
> - _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
> -
> - /* WaSwitchSolVfFArbitrationPriority:bdw */
> - I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);
>
> /* WaPsrDPAMaskVBlankInSRD:bdw */
> I915_WRITE(CHICKEN_PAR1_1,
> I915_READ(CHICKEN_PAR1_1) | DPA_MASK_VBLANK_SRD);
>
> /* WaPsrDPRSUnmaskVBlankInSRD:bdw */
> for_each_pipe(pipe) {
> I915_WRITE(CHICKEN_PIPESL_1(pipe),
> I915_READ(CHICKEN_PIPESL_1(pipe)) |
> BDW_DPRS_MASK_VBLANK_SRD);
> }
>
> - /* Use Force Non-Coherent whenever executing a 3D context. This is a
> - * workaround for for a possible hang in the unlikely event a TLB
> - * invalidation occurs during a PSD flush.
> - */
> - I915_WRITE(HDC_CHICKEN0,
> - I915_READ(HDC_CHICKEN0) |
> - _MASKED_BIT_ENABLE(HDC_FORCE_NON_COHERENT));
> -
> - /* WaVSRefCountFullforceMissDisable:bdw */
> - /* WaDSRefCountFullforceMissDisable:bdw */
> - I915_WRITE(GEN7_FF_THREAD_MODE,
> - I915_READ(GEN7_FF_THREAD_MODE) &
> - ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME));
> -
> /*
> * BSpec recommends 8x4 when MSAA is used,
> * however in practice 16x4 seems fastest.
> *
> * Note that PS/WM thread counts depend on the WIZ hashing
> * disable bit, which we don't touch here, but it's good
> * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
> */
> I915_WRITE(GEN7_GT_MODE,
> GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);

GT_MODE doesn't get clobbered by a reset? I would have expected it to
behave the same way as CACHE_MODE_{0,1).

> -
> - I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
> - _MASKED_BIT_ENABLE(GEN8_RC_SEMA_IDLE_MSG_DISABLE));
> -
> - /* WaDisableSDEUnitClockGating:bdw */
> - I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
> - GEN8_SDEUNIT_CLOCK_GATE_DISABLE);

And I would have expected the UCGCTL registers to not be clobbered. IIRC
they didn't get clobbered on my IVB, but my memory might be wrong here.

> -
> - /* Wa4x4STCOptimizationDisable:bdw */
> - I915_WRITE(CACHE_MODE_1,
> - _MASKED_BIT_ENABLE(GEN8_4x4_STC_OPTIMIZATION_DISABLE));
> }
>
> static void haswell_init_clock_gating(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> ilk_init_lp_watermarks(dev);
>
> /* L3 caching of data atomics doesn't work -- disable it. */
> I915_WRITE(HSW_SCRATCH1, HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index b3d8f76..6818e34 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -591,20 +591,85 @@ init_pipe_control(struct intel_engine_cs *ring)
> return 0;
>
> err_unpin:
> i915_gem_object_ggtt_unpin(ring->scratch.obj);
> err_unref:
> drm_gem_object_unreference(&ring->scratch.obj->base);
> err:
> return ret;
> }
>
> +static void bdw_init_workarounds(struct drm_device *dev)
> +{
> + struct drm_i915_private *dev_priv = dev->dev_private;
> +
> + /* WaDisablePartialInstShootdown:bdw */
> + I915_WRITE(GEN8_ROW_CHICKEN,
> + _MASKED_BIT_ENABLE(PARTIAL_INSTRUCTION_SHOOTDOWN_DISABLE));
> +
> + /* WaDisableThreadStallDopClockGating:bdw */
> + /* FIXME: Unclear whether we really need these on production bdw. */
> + I915_WRITE(GEN8_ROW_CHICKEN,
> + _MASKED_BIT_ENABLE(STALL_DOP_GATING_DISABLE));
> +
> + /*
> + * This GEN8_CENTROID_PIXEL_OPT_DIS W/A is only needed for
> + * pre-production hardware
> + */
> + I915_WRITE(HALF_SLICE_CHICKEN3,
> + _MASKED_BIT_ENABLE(GEN8_CENTROID_PIXEL_OPT_DIS));
> + I915_WRITE(HALF_SLICE_CHICKEN3,
> + _MASKED_BIT_ENABLE(GEN8_SAMPLER_POWER_BYPASS_DIS));
> + I915_WRITE(GAMTARBMODE, _MASKED_BIT_ENABLE(ARB_MODE_BWGTLB_DISABLE));
> +
> + I915_WRITE(_3D_CHICKEN3,
> + _MASKED_BIT_ENABLE(_3D_CHICKEN_SDE_LIMIT_FIFO_POLY_DEPTH(2)));
> +
> + I915_WRITE(COMMON_SLICE_CHICKEN2,
> + _MASKED_BIT_ENABLE(GEN8_CSC2_SBE_VUE_CACHE_CONSERVATIVE));
> +
> + I915_WRITE(GEN7_HALF_SLICE_CHICKEN1,
> + _MASKED_BIT_ENABLE(GEN7_SINGLE_SUBSCAN_DISPATCH_ENABLE));
> +
> + /* WaDisableDopClockGating:bdw May not be needed for production */
> + I915_WRITE(GEN7_ROW_CHICKEN2,
> + _MASKED_BIT_ENABLE(DOP_CLOCK_GATING_DISABLE));
> +
> + /* WaSwitchSolVfFArbitrationPriority:bdw */
> + I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);
> +
> + /* Use Force Non-Coherent whenever executing a 3D context. This is a
> + * workaround for for a possible hang in the unlikely event a TLB
> + * invalidation occurs during a PSD flush.
> + */
> + I915_WRITE(HDC_CHICKEN0,
> + I915_READ(HDC_CHICKEN0) |

You might kill this read since it's a masked register. Maybe as a
separate prep-patch.

> + _MASKED_BIT_ENABLE(HDC_FORCE_NON_COHERENT));
> +
> + /* WaVSRefCountFullforceMissDisable:bdw */
> + /* WaDSRefCountFullforceMissDisable:bdw */
> + I915_WRITE(GEN7_FF_THREAD_MODE,
> + I915_READ(GEN7_FF_THREAD_MODE) &
> + ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME));
> +
> + /* WaDisableSDEUnitClockGating:bdw */
> + I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
> + GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
> +
> + I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
> + _MASKED_BIT_ENABLE(GEN8_RC_SEMA_IDLE_MSG_DISABLE));
> +
> + /* Wa4x4STCOptimizationDisable:bdw */
> + I915_WRITE(CACHE_MODE_1,
> + _MASKED_BIT_ENABLE(GEN8_4x4_STC_OPTIMIZATION_DISABLE));

I think it would be nice to reorder this function a bit to keep similar registers
close to each other. The current mismash makes it easy to overlook a
workaround and then we may end up with duplicates (wouldn't be the first
time that happened).

> +}
> +
> static int init_render_ring(struct intel_engine_cs *ring)
> {
> struct drm_device *dev = ring->dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> int ret = init_ring_common(ring);
> if (ret)
> return ret;
>
> /* WaTimedSingleVertexDispatch:cl,bw,ctg,elk,ilk,snb */
> if (INTEL_INFO(dev)->gen >= 4 && INTEL_INFO(dev)->gen < 7)
> @@ -646,20 +711,23 @@ static int init_render_ring(struct intel_engine_cs *ring)
> I915_WRITE(CACHE_MODE_0,
> _MASKED_BIT_DISABLE(CM0_STC_EVICT_DISABLE_LRA_SNB));
> }
>
> if (INTEL_INFO(dev)->gen >= 6)
> I915_WRITE(INSTPM, _MASKED_BIT_ENABLE(INSTPM_FORCE_ORDERING));
>
> if (HAS_L3_DPF(dev))
> I915_WRITE_IMR(ring, ~GT_PARITY_ERROR(dev));
>
> + if (IS_BROADWELL(dev))
> + bdw_init_workarounds(dev);
> +
> return ret;
> }
>
> static void render_ring_cleanup(struct intel_engine_cs *ring)
> {
> struct drm_device *dev = ring->dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> if (dev_priv->semaphore_obj) {
> i915_gem_object_ggtt_unpin(dev_priv->semaphore_obj);
> --
> 1.9.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Ville Syrjälä
Intel OTC