diff mbox

[4/5] drm/i915: Create a new category of display WAs

Message ID 1518549212-34904-4-git-send-email-oscar.mateo@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

oscar.mateo@intel.com Feb. 13, 2018, 7:13 p.m. UTC 
Display workarounds do not need to be re-applied on a GPU reset
(this is, in Ville's words: "at the very least wasted effort [...]
and could even be actively harmful in case we end up clobbering
something the current display configuration depends on"). Therefore,
they have to be applied in a different place that GT ones so they
deserve their own category.

Initially, populate this with the WAs that were being applied in
init_clock_gating. Actually discriminating which of these WAS is
a real display WA, a GT WA or a context WA is left for the next
patch (as it requires a good deal of careful review).

v2: Rebased to carry the init_early nomenclature over (Chris)
v3:
  - Rebased to before the WAs are stored
  - Initially populate with all WAs in init_clock_gating
v4: Rebased

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c          | 304 +-----------------------------
 drivers/gpu/drm/i915/intel_workarounds.c | 309 +++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_workarounds.h |   2 +
 3 files changed, 319 insertions(+), 296 deletions(-)

Comments

Jani Nikula Feb. 13, 2018, 8:02 p.m. UTC | #1 
On Tue, 13 Feb 2018, Oscar Mateo <oscar.mateo@intel.com> wrote:
> @@ -8979,6 +8701,7 @@ static void i830_init_clock_gating(struct drm_i915_private *dev_priv)
>  void intel_init_clock_gating(struct drm_i915_private *dev_priv)
>  {
>  	dev_priv->display.init_clock_gating(dev_priv);
> +	intel_disp_workarounds_apply(dev_priv);

Please don't abbreviate display to disp, use the full word instead,
throughout the series. Rationale:

$ git grep disp_ -- drivers/gpu/drm/i915 | wc -l
8

$ git grep display_ -- drivers/gpu/drm/i915 | wc -l
752

> diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c

> +static void bdw_disp_workarounds_apply(struct drm_i915_private *dev_priv)

If you want to shorten the names within intel_workarounds.c please
abbreviate workarounds to wa instead. I think it should be obvious
within that file. But I don't mind longer names here. It's the long
names that are used throughout the driver that I'd avoid.


BR,
Jani.
Chris Wilson Feb. 13, 2018, 8:50 p.m. UTC | #2 
Quoting Jani Nikula (2018-02-13 20:02:55)
> On Tue, 13 Feb 2018, Oscar Mateo <oscar.mateo@intel.com> wrote:
> > @@ -8979,6 +8701,7 @@ static void i830_init_clock_gating(struct drm_i915_private *dev_priv)
> >  void intel_init_clock_gating(struct drm_i915_private *dev_priv)
> >  {
> >       dev_priv->display.init_clock_gating(dev_priv);
> > +     intel_disp_workarounds_apply(dev_priv);
> 
> Please don't abbreviate display to disp, use the full word instead,
> throughout the series. Rationale:

And in general, use the full name for global functions and data. They
are written infrequently so not overburdensome, but the clarity is a
good reward. Locals by contrast quite often are more readable when using
(consistent) shorthand, or at least I think so.
-Chris
oscar.mateo@intel.com Feb. 13, 2018, 9:34 p.m. UTC | #3 
On 2/13/2018 12:50 PM, Chris Wilson wrote:
> Quoting Jani Nikula (2018-02-13 20:02:55)
>> On Tue, 13 Feb 2018, Oscar Mateo <oscar.mateo@intel.com> wrote:
>>> @@ -8979,6 +8701,7 @@ static void i830_init_clock_gating(struct drm_i915_private *dev_priv)
>>>   void intel_init_clock_gating(struct drm_i915_private *dev_priv)
>>>   {
>>>        dev_priv->display.init_clock_gating(dev_priv);
>>> +     intel_disp_workarounds_apply(dev_priv);
>> Please don't abbreviate display to disp, use the full word instead,
>> throughout the series. Rationale:
> And in general, use the full name for global functions and data. They
> are written infrequently so not overburdensome, but the clarity is a
> good reward. Locals by contrast quite often are more readable when using
> (consistent) shorthand, or at least I think so.
> -Chris

Sure, makes sense. I'll rename a few things and resend.
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index b026b02..6917a9d 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -29,6 +29,7 @@ 
 #include <drm/drm_plane_helper.h>
 #include "i915_drv.h"
 #include "intel_drv.h"
+#include "intel_workarounds.h"
 #include "../../../platform/x86/intel_ips.h"
 #include <linux/module.h>
 #include <drm/drm_atomic_helper.h>
@@ -53,92 +54,6 @@ 
  * require higher latency to switch to and wake up.
  */
 
-static void gen9_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	if (HAS_LLC(dev_priv)) {
-		/*
-		 * WaCompressedResourceDisplayNewHashMode:skl,kbl
-		 * Display WA #0390: skl,kbl
-		 *
-		 * Must match Sampler, Pixel Back End, and Media. See
-		 * WaCompressedResourceSamplerPbeMediaNewHashMode.
-		 */
-		I915_WRITE(CHICKEN_PAR1_1,
-			   I915_READ(CHICKEN_PAR1_1) |
-			   SKL_DE_COMPRESSED_HASH_MODE);
-	}
-
-	/* See Bspec note for PSR2_CTL bit 31, Wa#828:skl,bxt,kbl,cfl */
-	I915_WRITE(CHICKEN_PAR1_1,
-		   I915_READ(CHICKEN_PAR1_1) | SKL_EDP_PSR_FIX_RDWRAP);
-
-	/* WaEnableChickenDCPR:skl,bxt,kbl,glk,cfl */
-	I915_WRITE(GEN8_CHICKEN_DCPR_1,
-		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
-
-	/* WaFbcTurnOffFbcWatermark:skl,bxt,kbl,cfl */
-	/* WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl */
-	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
-		   DISP_FBC_WM_DIS |
-		   DISP_FBC_MEMORY_WAKE);
-
-	/* WaFbcHighMemBwCorruptionAvoidance:skl,bxt,kbl,cfl */
-	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_DISABLE_DUMMY0);
-
-	if (IS_SKYLAKE(dev_priv)) {
-		/* WaDisableDopClockGating */
-		I915_WRITE(GEN7_MISCCPCTL, I915_READ(GEN7_MISCCPCTL)
-			   & ~GEN7_DOP_CLOCK_GATE_ENABLE);
-	}
-}
-
-static void bxt_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	gen9_init_clock_gating(dev_priv);
-
-	/* WaDisableSDEUnitClockGating:bxt */
-	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
-		   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
-
-	/*
-	 * FIXME:
-	 * GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ applies on 3x6 GT SKUs only.
-	 */
-	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
-		   GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ);
-
-	/*
-	 * Wa: Backlight PWM may stop in the asserted state, causing backlight
-	 * to stay fully on.
-	 */
-	I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
-		   PWM1_GATING_DIS | PWM2_GATING_DIS);
-}
-
-static void glk_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	gen9_init_clock_gating(dev_priv);
-
-	/*
-	 * WaDisablePWMClockGating:glk
-	 * Backlight PWM may stop in the asserted state, causing backlight
-	 * to stay fully on.
-	 */
-	I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
-		   PWM1_GATING_DIS | PWM2_GATING_DIS);
-
-	/* WaDDIIOTimeout:glk */
-	if (IS_GLK_REVID(dev_priv, 0, GLK_REVID_A1)) {
-		u32 val = I915_READ(CHICKEN_MISC_2);
-		val &= ~(GLK_CL0_PWR_DOWN |
-			 GLK_CL1_PWR_DOWN |
-			 GLK_CL2_PWR_DOWN);
-		I915_WRITE(CHICKEN_MISC_2, val);
-	}
-
-}
-
 static void i915_pineview_get_mem_freq(struct drm_i915_private *dev_priv)
 {
 	u32 tmp;
@@ -8457,168 +8372,9 @@  static void lpt_suspend_hw(struct drm_i915_private *dev_priv)
 	}
 }
 
-static void gen8_set_l3sqc_credits(struct drm_i915_private *dev_priv,
-				   int general_prio_credits,
-				   int high_prio_credits)
-{
-	u32 misccpctl;
-	u32 val;
-
-	/* WaTempDisableDOPClkGating:bdw */
-	misccpctl = I915_READ(GEN7_MISCCPCTL);
-	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
-
-	val = I915_READ(GEN8_L3SQCREG1);
-	val &= ~L3_PRIO_CREDITS_MASK;
-	val |= L3_GENERAL_PRIO_CREDITS(general_prio_credits);
-	val |= L3_HIGH_PRIO_CREDITS(high_prio_credits);
-	I915_WRITE(GEN8_L3SQCREG1, val);
-
-	/*
-	 * Wait at least 100 clocks before re-enabling clock gating.
-	 * See the definition of L3SQCREG1 in BSpec.
-	 */
-	POSTING_READ(GEN8_L3SQCREG1);
-	udelay(1);
-	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
-}
-
-static void cnp_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	if (!HAS_PCH_CNP(dev_priv))
-		return;
-
-	/* Display WA #1181: cnp */
-	I915_WRITE(SOUTH_DSPCLK_GATE_D, I915_READ(SOUTH_DSPCLK_GATE_D) |
-		   CNP_PWM_CGE_GATING_DISABLE);
-}
-
-static void cnl_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	u32 val;
-	cnp_init_clock_gating(dev_priv);
-
-	/* This is not an Wa. Enable for better image quality */
-	I915_WRITE(_3D_CHICKEN3,
-		   _MASKED_BIT_ENABLE(_3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE));
-
-	/* WaEnableChickenDCPR:cnl */
-	I915_WRITE(GEN8_CHICKEN_DCPR_1,
-		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
-
-	/* WaFbcWakeMemOn:cnl */
-	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
-		   DISP_FBC_MEMORY_WAKE);
-
-	val = I915_READ(SLICE_UNIT_LEVEL_CLKGATE);
-	/* ReadHitWriteOnlyDisable:cnl */
-	val |= RCCUNIT_CLKGATE_DIS;
-	/* WaSarbUnitClockGatingDisable:cnl (pre-prod) */
-	if (IS_CNL_REVID(dev_priv, CNL_REVID_A0, CNL_REVID_B0))
-		val |= SARBUNIT_CLKGATE_DIS;
-	I915_WRITE(SLICE_UNIT_LEVEL_CLKGATE, val);
-
-	/* WaDisableVFclkgate:cnl */
-	val = I915_READ(UNSLICE_UNIT_LEVEL_CLKGATE);
-	val |= VFUNIT_CLKGATE_DIS;
-	I915_WRITE(UNSLICE_UNIT_LEVEL_CLKGATE, val);
-}
-
-static void cfl_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	cnp_init_clock_gating(dev_priv);
-	gen9_init_clock_gating(dev_priv);
-
-	/* WaFbcNukeOnHostModify:cfl */
-	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
-}
-
-static void kbl_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	gen9_init_clock_gating(dev_priv);
-
-	/* WaDisableSDEUnitClockGating:kbl */
-	if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
-		I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
-			   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
-
-	/* WaDisableGamClockGating:kbl */
-	if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
-		I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
-			   GEN6_GAMUNIT_CLOCK_GATE_DISABLE);
-
-	/* WaFbcNukeOnHostModify:kbl */
-	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
-}
-
-static void skl_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	gen9_init_clock_gating(dev_priv);
-
-	/* WAC6entrylatency:skl */
-	I915_WRITE(FBC_LLC_READ_CTRL, I915_READ(FBC_LLC_READ_CTRL) |
-		   FBC_LLC_FULLY_OPEN);
-
-	/* WaFbcNukeOnHostModify:skl */
-	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
-		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
-}
-
 static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)
 {
-	/* The GTT cache must be disabled if the system is using 2M pages. */
-	bool can_use_gtt_cache = !HAS_PAGE_SIZES(dev_priv,
-						 I915_GTT_PAGE_SIZE_2M);
-	enum pipe pipe;
-
-	/* 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(dev_priv, pipe) {
-		I915_WRITE(CHICKEN_PIPESL_1(pipe),
-			   I915_READ(CHICKEN_PIPESL_1(pipe)) |
-			   BDW_DPRS_MASK_VBLANK_SRD);
-	}
-
-	/* 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));
-
-	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);
-
-	/* WaProgramL3SqcReg1Default:bdw */
-	gen8_set_l3sqc_credits(dev_priv, 30, 2);
-
-	/* WaGttCachingOffByDefault:bdw */
-	I915_WRITE(HSW_GTT_CACHE_EN, can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
-
-	/* WaKVMNotificationOnConfigChange:bdw */
-	I915_WRITE(CHICKEN_PAR2_1, I915_READ(CHICKEN_PAR2_1)
-		   | KVM_CONFIG_CHANGE_NOTIFICATION_SELECT);
-
 	lpt_init_clock_gating(dev_priv);
-
-	/* WaDisableDopClockGating:bdw
-	 *
-	 * Also see the CHICKEN2 write in bdw_init_workarounds() to disable DOP
-	 * clock gating.
-	 */
-	I915_WRITE(GEN6_UCGCTL1,
-		   I915_READ(GEN6_UCGCTL1) | GEN6_EU_TCUNIT_CLOCK_GATE_DISABLE);
 }
 
 static void hsw_init_clock_gating(struct drm_i915_private *dev_priv)
@@ -8844,40 +8600,6 @@  static void vlv_init_clock_gating(struct drm_i915_private *dev_priv)
 	I915_WRITE(VLV_GUNIT_CLOCK_GATE, GCFG_DIS);
 }
 
-static void chv_init_clock_gating(struct drm_i915_private *dev_priv)
-{
-	/* WaVSRefCountFullforceMissDisable:chv */
-	/* WaDSRefCountFullforceMissDisable:chv */
-	I915_WRITE(GEN7_FF_THREAD_MODE,
-		   I915_READ(GEN7_FF_THREAD_MODE) &
-		   ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME));
-
-	/* WaDisableSemaphoreAndSyncFlipWait:chv */
-	I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
-		   _MASKED_BIT_ENABLE(GEN8_RC_SEMA_IDLE_MSG_DISABLE));
-
-	/* WaDisableCSUnitClockGating:chv */
-	I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
-		   GEN6_CSUNIT_CLOCK_GATE_DISABLE);
-
-	/* WaDisableSDEUnitClockGating:chv */
-	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
-		   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
-
-	/*
-	 * WaProgramL3SqcReg1Default:chv
-	 * See gfxspecs/Related Documents/Performance Guide/
-	 * LSQC Setting Recommendations.
-	 */
-	gen8_set_l3sqc_credits(dev_priv, 38, 2);
-
-	/*
-	 * GTT cache may not work with big pages, so if those
-	 * are ever enabled GTT cache may need to be disabled.
-	 */
-	I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL);
-}
-
 static void g4x_init_clock_gating(struct drm_i915_private *dev_priv)
 {
 	uint32_t dspclk_gate;
@@ -8979,6 +8701,7 @@  static void i830_init_clock_gating(struct drm_i915_private *dev_priv)
 void intel_init_clock_gating(struct drm_i915_private *dev_priv)
 {
 	dev_priv->display.init_clock_gating(dev_priv);
+	intel_disp_workarounds_apply(dev_priv);
 }
 
 void intel_suspend_hw(struct drm_i915_private *dev_priv)
@@ -8997,28 +8720,17 @@  static void nop_init_clock_gating(struct drm_i915_private *dev_priv)
  * @dev_priv: device private
  *
  * Setup the hooks that configure which clocks of a given platform can be
- * gated and also apply various GT and display specific workarounds for these
- * platforms. Note that some GT specific workarounds are applied separately
- * when GPU contexts or batchbuffers start their execution.
+ * gated.
  */
 void intel_init_clock_gating_hooks(struct drm_i915_private *dev_priv)
 {
-	if (IS_CANNONLAKE(dev_priv))
-		dev_priv->display.init_clock_gating = cnl_init_clock_gating;
-	else if (IS_COFFEELAKE(dev_priv))
-		dev_priv->display.init_clock_gating = cfl_init_clock_gating;
-	else if (IS_SKYLAKE(dev_priv))
-		dev_priv->display.init_clock_gating = skl_init_clock_gating;
-	else if (IS_KABYLAKE(dev_priv))
-		dev_priv->display.init_clock_gating = kbl_init_clock_gating;
-	else if (IS_BROXTON(dev_priv))
-		dev_priv->display.init_clock_gating = bxt_init_clock_gating;
-	else if (IS_GEMINILAKE(dev_priv))
-		dev_priv->display.init_clock_gating = glk_init_clock_gating;
+	if (IS_CANNONLAKE(dev_priv) || IS_COFFEELAKE(dev_priv) ||
+	    IS_GEMINILAKE(dev_priv) || IS_KABYLAKE(dev_priv)   ||
+	    IS_BROXTON(dev_priv)    || IS_SKYLAKE(dev_priv)    ||
+	    IS_CHERRYVIEW(dev_priv))
+		dev_priv->display.init_clock_gating = nop_init_clock_gating;
 	else if (IS_BROADWELL(dev_priv))
 		dev_priv->display.init_clock_gating = bdw_init_clock_gating;
-	else if (IS_CHERRYVIEW(dev_priv))
-		dev_priv->display.init_clock_gating = chv_init_clock_gating;
 	else if (IS_HASWELL(dev_priv))
 		dev_priv->display.init_clock_gating = hsw_init_clock_gating;
 	else if (IS_IVYBRIDGE(dev_priv))
diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c
index abd4e23..8a27c13 100644
--- a/drivers/gpu/drm/i915/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/intel_workarounds.c
@@ -647,6 +647,315 @@  void intel_gt_workarounds_apply(struct drm_i915_private *dev_priv)
 		MISSING_CASE(INTEL_GEN(dev_priv));
 }
 
+static void gen8_set_l3sqc_credits(struct drm_i915_private *dev_priv,
+				   int general_prio_credits,
+				   int high_prio_credits)
+{
+	u32 misccpctl;
+	u32 val;
+
+	/* WaTempDisableDOPClkGating:bdw */
+	misccpctl = I915_READ(GEN7_MISCCPCTL);
+	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
+
+	val = I915_READ(GEN8_L3SQCREG1);
+	val &= ~L3_PRIO_CREDITS_MASK;
+	val |= L3_GENERAL_PRIO_CREDITS(general_prio_credits);
+	val |= L3_HIGH_PRIO_CREDITS(high_prio_credits);
+	I915_WRITE(GEN8_L3SQCREG1, val);
+
+	/*
+	 * Wait at least 100 clocks before re-enabling clock gating.
+	 * See the definition of L3SQCREG1 in BSpec.
+	 */
+	POSTING_READ(GEN8_L3SQCREG1);
+	udelay(1);
+	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
+}
+
+static void bdw_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	/* The GTT cache must be disabled if the system is using 2M pages. */
+	bool can_use_gtt_cache = !HAS_PAGE_SIZES(dev_priv,
+						 I915_GTT_PAGE_SIZE_2M);
+	enum pipe pipe;
+
+	/* 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(dev_priv, pipe) {
+		I915_WRITE(CHICKEN_PIPESL_1(pipe),
+			   I915_READ(CHICKEN_PIPESL_1(pipe)) |
+			   BDW_DPRS_MASK_VBLANK_SRD);
+	}
+
+	/* 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));
+
+	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);
+
+	/* WaProgramL3SqcReg1Default:bdw */
+	gen8_set_l3sqc_credits(dev_priv, 30, 2);
+
+	/* WaGttCachingOffByDefault:bdw */
+	I915_WRITE(HSW_GTT_CACHE_EN, can_use_gtt_cache ? GTT_CACHE_EN_ALL : 0);
+
+	/* WaKVMNotificationOnConfigChange:bdw */
+	I915_WRITE(CHICKEN_PAR2_1, I915_READ(CHICKEN_PAR2_1)
+		   | KVM_CONFIG_CHANGE_NOTIFICATION_SELECT);
+
+	/* WaDisableDopClockGating:bdw
+	 *
+	 * Also see the CHICKEN2 write in bdw_init_workarounds() to disable DOP
+	 * clock gating.
+	 */
+	I915_WRITE(GEN6_UCGCTL1,
+		   I915_READ(GEN6_UCGCTL1) | GEN6_EU_TCUNIT_CLOCK_GATE_DISABLE);
+}
+
+static void chv_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	/* WaVSRefCountFullforceMissDisable:chv */
+	/* WaDSRefCountFullforceMissDisable:chv */
+	I915_WRITE(GEN7_FF_THREAD_MODE,
+		   I915_READ(GEN7_FF_THREAD_MODE) &
+		   ~(GEN8_FF_DS_REF_CNT_FFME | GEN7_FF_VS_REF_CNT_FFME));
+
+	/* WaDisableSemaphoreAndSyncFlipWait:chv */
+	I915_WRITE(GEN6_RC_SLEEP_PSMI_CONTROL,
+		   _MASKED_BIT_ENABLE(GEN8_RC_SEMA_IDLE_MSG_DISABLE));
+
+	/* WaDisableCSUnitClockGating:chv */
+	I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
+		   GEN6_CSUNIT_CLOCK_GATE_DISABLE);
+
+	/* WaDisableSDEUnitClockGating:chv */
+	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
+		   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
+
+	/*
+	 * WaProgramL3SqcReg1Default:chv
+	 * See gfxspecs/Related Documents/Performance Guide/
+	 * LSQC Setting Recommendations.
+	 */
+	gen8_set_l3sqc_credits(dev_priv, 38, 2);
+
+	/*
+	 * GTT cache may not work with big pages, so if those
+	 * are ever enabled GTT cache may need to be disabled.
+	 */
+	I915_WRITE(HSW_GTT_CACHE_EN, GTT_CACHE_EN_ALL);
+}
+
+static void gen9_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	if (HAS_LLC(dev_priv)) {
+		/*
+		 * WaCompressedResourceDisplayNewHashMode:skl,kbl
+		 * Display WA #0390: skl,kbl
+		 *
+		 * Must match Sampler, Pixel Back End, and Media. See
+		 * WaCompressedResourceSamplerPbeMediaNewHashMode.
+		 */
+		I915_WRITE(CHICKEN_PAR1_1,
+			   I915_READ(CHICKEN_PAR1_1) |
+			   SKL_DE_COMPRESSED_HASH_MODE);
+	}
+
+	/* See Bspec note for PSR2_CTL bit 31, Wa#828:skl,bxt,kbl,cfl */
+	I915_WRITE(CHICKEN_PAR1_1,
+		   I915_READ(CHICKEN_PAR1_1) | SKL_EDP_PSR_FIX_RDWRAP);
+
+	/* WaEnableChickenDCPR:skl,bxt,kbl,glk,cfl */
+	I915_WRITE(GEN8_CHICKEN_DCPR_1,
+		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
+
+	/* WaFbcTurnOffFbcWatermark:skl,bxt,kbl,cfl */
+	/* WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl */
+	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
+		   DISP_FBC_WM_DIS |
+		   DISP_FBC_MEMORY_WAKE);
+
+	/* WaFbcHighMemBwCorruptionAvoidance:skl,bxt,kbl,cfl */
+	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+		   ILK_DPFC_DISABLE_DUMMY0);
+
+	if (IS_SKYLAKE(dev_priv)) {
+		/* WaDisableDopClockGating */
+		I915_WRITE(GEN7_MISCCPCTL, I915_READ(GEN7_MISCCPCTL)
+			   & ~GEN7_DOP_CLOCK_GATE_ENABLE);
+	}
+}
+
+static void skl_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	gen9_disp_workarounds_apply(dev_priv);
+
+	/* WAC6entrylatency:skl */
+	I915_WRITE(FBC_LLC_READ_CTRL, I915_READ(FBC_LLC_READ_CTRL) |
+		   FBC_LLC_FULLY_OPEN);
+
+	/* WaFbcNukeOnHostModify:skl */
+	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+}
+
+static void bxt_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	gen9_disp_workarounds_apply(dev_priv);
+
+	/* WaDisableSDEUnitClockGating:bxt */
+	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
+		   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
+
+	/*
+	 * FIXME:
+	 * GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ applies on 3x6 GT SKUs only.
+	 */
+	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
+		   GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ);
+
+	/*
+	 * Wa: Backlight PWM may stop in the asserted state, causing backlight
+	 * to stay fully on.
+	 */
+	I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
+		   PWM1_GATING_DIS | PWM2_GATING_DIS);
+}
+
+static void kbl_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	gen9_disp_workarounds_apply(dev_priv);
+
+	/* WaDisableSDEUnitClockGating:kbl */
+	if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
+		I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
+			   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
+
+	/* WaDisableGamClockGating:kbl */
+	if (IS_KBL_REVID(dev_priv, 0, KBL_REVID_B0))
+		I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
+			   GEN6_GAMUNIT_CLOCK_GATE_DISABLE);
+
+	/* WaFbcNukeOnHostModify:kbl */
+	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+}
+
+static void glk_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	gen9_disp_workarounds_apply(dev_priv);
+
+	/*
+	 * WaDisablePWMClockGating:glk
+	 * Backlight PWM may stop in the asserted state, causing backlight
+	 * to stay fully on.
+	 */
+	I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) |
+		   PWM1_GATING_DIS | PWM2_GATING_DIS);
+
+	/* WaDDIIOTimeout:glk */
+	if (IS_GLK_REVID(dev_priv, 0, GLK_REVID_A1)) {
+		u32 val = I915_READ(CHICKEN_MISC_2);
+		val &= ~(GLK_CL0_PWR_DOWN |
+			 GLK_CL1_PWR_DOWN |
+			 GLK_CL2_PWR_DOWN);
+		I915_WRITE(CHICKEN_MISC_2, val);
+	}
+}
+
+static void cnp_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	if (!HAS_PCH_CNP(dev_priv))
+		return;
+
+	/* Display WA #1181: cnp */
+	I915_WRITE(SOUTH_DSPCLK_GATE_D, I915_READ(SOUTH_DSPCLK_GATE_D) |
+		   CNP_PWM_CGE_GATING_DISABLE);
+}
+
+static void cfl_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	cnp_disp_workarounds_apply(dev_priv);
+	gen9_disp_workarounds_apply(dev_priv);
+
+	/* WaFbcNukeOnHostModify:cfl */
+	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+}
+
+static void cnl_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	u32 val;
+	cnp_disp_workarounds_apply(dev_priv);
+
+	/* This is not an Wa. Enable for better image quality */
+	I915_WRITE(_3D_CHICKEN3,
+		   _MASKED_BIT_ENABLE(_3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE));
+
+	/* WaEnableChickenDCPR:cnl */
+	I915_WRITE(GEN8_CHICKEN_DCPR_1,
+		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
+
+	/* WaFbcWakeMemOn:cnl */
+	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
+		   DISP_FBC_MEMORY_WAKE);
+
+	val = I915_READ(SLICE_UNIT_LEVEL_CLKGATE);
+	/* ReadHitWriteOnlyDisable:cnl */
+	val |= RCCUNIT_CLKGATE_DIS;
+	/* WaSarbUnitClockGatingDisable:cnl (pre-prod) */
+	if (IS_CNL_REVID(dev_priv, CNL_REVID_A0, CNL_REVID_B0))
+		val |= SARBUNIT_CLKGATE_DIS;
+	I915_WRITE(SLICE_UNIT_LEVEL_CLKGATE, val);
+
+	/* WaDisableVFclkgate:cnl */
+	val = I915_READ(UNSLICE_UNIT_LEVEL_CLKGATE);
+	val |= VFUNIT_CLKGATE_DIS;
+	I915_WRITE(UNSLICE_UNIT_LEVEL_CLKGATE, val);
+}
+
+/*
+ * FIXME: Some of the WAs applied here are incorrectly classified as Display
+ * WAs. We still need to go through them and apply them in the right place.
+ */
+void intel_disp_workarounds_apply(struct drm_i915_private *dev_priv)
+{
+	if (INTEL_GEN(dev_priv) < 8)
+		return;
+	else if (IS_BROADWELL(dev_priv))
+		bdw_disp_workarounds_apply(dev_priv);
+	else if (IS_CHERRYVIEW(dev_priv))
+		chv_disp_workarounds_apply(dev_priv);
+	else if (IS_SKYLAKE(dev_priv))
+		skl_disp_workarounds_apply(dev_priv);
+	else if (IS_BROXTON(dev_priv))
+		bxt_disp_workarounds_apply(dev_priv);
+	else if (IS_KABYLAKE(dev_priv))
+		kbl_disp_workarounds_apply(dev_priv);
+	else if (IS_GEMINILAKE(dev_priv))
+		glk_disp_workarounds_apply(dev_priv);
+	else if (IS_COFFEELAKE(dev_priv))
+		cfl_disp_workarounds_apply(dev_priv);
+	else if (IS_CANNONLAKE(dev_priv))
+		cnl_disp_workarounds_apply(dev_priv);
+	else
+		MISSING_CASE(INTEL_GEN(dev_priv));
+}
+
 static int wa_ring_whitelist_reg(struct intel_engine_cs *engine,
 				 i915_reg_t reg)
 {
diff --git a/drivers/gpu/drm/i915/intel_workarounds.h b/drivers/gpu/drm/i915/intel_workarounds.h
index 8c01a3b..5c37f65 100644
--- a/drivers/gpu/drm/i915/intel_workarounds.h
+++ b/drivers/gpu/drm/i915/intel_workarounds.h
@@ -12,6 +12,8 @@ 
 
 void intel_gt_workarounds_apply(struct drm_i915_private *dev_priv);
 
+void intel_disp_workarounds_apply(struct drm_i915_private *dev_priv);
+
 int intel_whitelist_workarounds_apply(struct intel_engine_cs *engine);
 
 int intel_engine_init_bb_workarounds(struct intel_engine_cs *engine);