From 509e7c23c4ab3996fffdd3b73ac868ca61d884b9 Mon Sep 17 00:00:00 2001 From: Yunwei Zhang Date: Fri, 18 May 2018 15:39:57 -0700 Subject: [PATCH] drm/i915/cnl: Implement WaProgramMgsrForCorrectSliceSpecificMmioReads WaProgramMgsrForCorrectSliceSpecificMmioReads dictate that before any MMIO read into Slice/Subslice specific registers, MCR packet control register(0xFDC) needs to be programmed to point to any enabled slice/subslice pair. Otherwise, incorrect value will be returned. However, that means each subsequent MMIO read will be forwarded to a specific slice/subslice combination as read is unicast. This is OK since slice/subslice specific register values are consistent in almost all cases across slice/subslice. There are rare occasions such as INSTDONE that this value will be dependent on slice/subslice combo, in such cases, we need to program 0xFDC and recover this after. This is already covered by read_subslice_reg. Also, 0xFDC will lose its information after TDR/engine reset/power state change. References: HSD#1405586840, BSID#0575 v2: - use fls() instead of find_last_bit() (Chris) - added INTEL_SSEU to extract sseu from device info. (Chris) v3: - rebase on latest tip v5: - Added references (Mika) - Change the ordered of passing arguments and etc. (Ursulin) v7: - Moved WA explanation Comments(Oscar) - Rebased. v8: - Renamed sanitize_mcr to calculate_s_ss_select. (Oscar) - calculate s/ss selector instead of whole mcr. (Oscar) v9: - Updated function name (Oscar) - Remove redundant variables (Oscar) v10: - Separate pre-GEN10 and GEN11 mask. (Oscar) Cc: Oscar Mateo Cc: Michel Thierry Cc: Joonas Lahtinen Cc: Chris Wilson Cc: Mika Kuoppala Cc: Tvrtko Ursulin Signed-off-by: Yunwei Zhang Reviewed-by: Oscar Mateo Signed-off-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/1526683197-24656-1-git-send-email-yunwei.zhang@intel.com --- drivers/gpu/drm/i915/i915_drv.h | 2 ++ drivers/gpu/drm/i915/intel_engine_cs.c | 30 ++++++++++++++++++++---- drivers/gpu/drm/i915/intel_workarounds.c | 27 +++++++++++++++++++++ 3 files changed, 54 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index b86ed6401120e..1b8bd84f07995 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2743,6 +2743,8 @@ int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool on); int intel_engines_init_mmio(struct drm_i915_private *dev_priv); int intel_engines_init(struct drm_i915_private *dev_priv); +u32 intel_calculate_mcr_s_ss_select(struct drm_i915_private *dev_priv); + /* intel_hotplug.c */ void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, u32 pin_mask, u32 long_mask); diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 0c1f084ee5936..ad28680390b8d 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -819,12 +819,29 @@ const char *i915_cache_level_str(struct drm_i915_private *i915, int type) } } +u32 intel_calculate_mcr_s_ss_select(struct drm_i915_private *dev_priv) +{ + const struct sseu_dev_info *sseu = &(INTEL_INFO(dev_priv)->sseu); + u32 mcr_s_ss_select; + u32 slice = fls(sseu->slice_mask); + u32 subslice = fls(sseu->subslice_mask[slice]); + + if (INTEL_GEN(dev_priv) == 10) + mcr_s_ss_select = GEN8_MCR_SLICE(slice) | + GEN8_MCR_SUBSLICE(subslice); + else + mcr_s_ss_select = 0; + + return mcr_s_ss_select; +} + static inline uint32_t read_subslice_reg(struct drm_i915_private *dev_priv, int slice, int subslice, i915_reg_t reg) { uint32_t mcr_slice_subslice_mask; uint32_t mcr_slice_subslice_select; + uint32_t default_mcr_s_ss_select; uint32_t mcr; uint32_t ret; enum forcewake_domains fw_domains; @@ -841,6 +858,8 @@ read_subslice_reg(struct drm_i915_private *dev_priv, int slice, GEN8_MCR_SUBSLICE(subslice); } + default_mcr_s_ss_select = intel_calculate_mcr_s_ss_select(dev_priv); + fw_domains = intel_uncore_forcewake_for_reg(dev_priv, reg, FW_REG_READ); fw_domains |= intel_uncore_forcewake_for_reg(dev_priv, @@ -851,11 +870,10 @@ read_subslice_reg(struct drm_i915_private *dev_priv, int slice, intel_uncore_forcewake_get__locked(dev_priv, fw_domains); mcr = I915_READ_FW(GEN8_MCR_SELECTOR); - /* - * The HW expects the slice and sublice selectors to be reset to 0 - * after reading out the registers. - */ - WARN_ON_ONCE(mcr & mcr_slice_subslice_mask); + + WARN_ON_ONCE((mcr & mcr_slice_subslice_mask) != + default_mcr_s_ss_select); + mcr &= ~mcr_slice_subslice_mask; mcr |= mcr_slice_subslice_select; I915_WRITE_FW(GEN8_MCR_SELECTOR, mcr); @@ -863,6 +881,8 @@ read_subslice_reg(struct drm_i915_private *dev_priv, int slice, ret = I915_READ_FW(reg); mcr &= ~mcr_slice_subslice_mask; + mcr |= default_mcr_s_ss_select; + I915_WRITE_FW(GEN8_MCR_SELECTOR, mcr); intel_uncore_forcewake_put__locked(dev_priv, fw_domains); diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c index 2df3538ceba54..720d8635c2cf2 100644 --- a/drivers/gpu/drm/i915/intel_workarounds.c +++ b/drivers/gpu/drm/i915/intel_workarounds.c @@ -672,8 +672,35 @@ static void cfl_gt_workarounds_apply(struct drm_i915_private *dev_priv) GAMT_ECO_ENABLE_IN_PLACE_DECOMPRESS); } +static void wa_init_mcr(struct drm_i915_private *dev_priv) +{ + u32 mcr; + u32 mcr_slice_subslice_mask; + + mcr = I915_READ(GEN8_MCR_SELECTOR); + + mcr_slice_subslice_mask = GEN8_MCR_SLICE_MASK | + GEN8_MCR_SUBSLICE_MASK; + /* + * WaProgramMgsrForCorrectSliceSpecificMmioReads:cnl + * Before any MMIO read into slice/subslice specific registers, MCR + * packet control register needs to be programmed to point to any + * enabled s/ss pair. Otherwise, incorrect values will be returned. + * This means each subsequent MMIO read will be forwarded to an + * specific s/ss combination, but this is OK since these registers + * are consistent across s/ss in almost all cases. In the rare + * occasions, such as INSTDONE, where this value is dependent + * on s/ss combo, the read should be done with read_subslice_reg. + */ + mcr &= ~mcr_slice_subslice_mask; + mcr |= intel_calculate_mcr_s_ss_select(dev_priv); + I915_WRITE(GEN8_MCR_SELECTOR, mcr); +} + static void cnl_gt_workarounds_apply(struct drm_i915_private *dev_priv) { + wa_init_mcr(dev_priv); + /* WaDisableI2mCycleOnWRPort:cnl (pre-prod) */ if (IS_CNL_REVID(dev_priv, CNL_REVID_B0, CNL_REVID_B0)) I915_WRITE(GAMT_CHKN_BIT_REG, -- 2.39.5