[Intel-gfx] [PATCH 08/12] drm/i915: Use mmio workaround list for skl/bxt

[Mika Kuoppala]

Some registers are, naturally, lost in gpu reset/suspend cycle.
And some registers, for example in display domain and are not subject
to gpu reset so they retain their contents.

As hang recovery triggers a reset, recoverable gpu hang can currently
flush out essential workarounds and cause havoc later on.

When register GEN8_GARBNTL is missing the WaEnableGapsTsvCreditFix:skl,
it can cause random system hangs [1]. This workaround was added in:
commit 245d96670d26 ("drm/i915:skl: Add WaEnableGapsTsvCreditFix").
But another set of system hangs were observed and the failure pattern
indicated that there was random gpu hang preceding the system hang [2].
This lead to the realization that we lose this workaround and BDW_SCRATCH1
on reset.

Add workarounds in skl/bxt init clock gating path to mmio workaround
list. This exposes these registers to the same testing mechanism in use
with the lri workarounds, gem_workarounds.

References: [1] https://bugs.freedesktop.org/show_bug.cgi?id=90854
References: https://bugs.freedesktop.org/show_bug.cgi?id=92315
Testcase: igt/gem_workarounds
Reported-by: Tomi Sarvela <tomix.p.sarvela at intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index e97f271..61136e1 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -73,12 +73,11 @@ static void gen9_init_clock_gating(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	/* WaEnableLbsSlaRetryTimerDecrement:skl */
-	I915_WRITE(BDW_SCRATCH1, I915_READ(BDW_SCRATCH1) |
+	WA_SET_BIT(MMIO, BDW_SCRATCH1,
 		   GEN9_LBS_SLA_RETRY_TIMER_DECREMENT_ENABLE);
 
 	/* WaDisableKillLogic:bxt,skl */
-	I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) |
-		   ECOCHK_DIS_TLB);
+	WA_SET_BIT(MMIO, GAM_ECOCHK, ECOCHK_DIS_TLB);
 }
 
 static void skl_init_clock_gating(struct drm_device *dev)
@@ -89,12 +88,11 @@ static void skl_init_clock_gating(struct drm_device *dev)
 
 	if (INTEL_REVID(dev) <= SKL_REVID_D0) {
 		/* WaDisableHDCInvalidation:skl */
-		I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) |
-			   BDW_DISABLE_HDC_INVALIDATION);
+		WA_SET_BIT(MMIO, GAM_ECOCHK, BDW_DISABLE_HDC_INVALIDATION);
 
 		/* WaDisableChickenBitTSGBarrierAckForFFSliceCS:skl */
-		I915_WRITE(FF_SLICE_CS_CHICKEN2,
-			   _MASKED_BIT_ENABLE(GEN9_TSG_BARRIER_ACK_DISABLE));
+		WA_SET_BIT_MASKED(MMIO, FF_SLICE_CS_CHICKEN2,
+				  GEN9_TSG_BARRIER_ACK_DISABLE);
 	}
 
 	/* GEN8_L3SQCREG4 has a dependency with WA batch so any new changes
@@ -102,13 +100,12 @@ static void skl_init_clock_gating(struct drm_device *dev)
 	 */
 	if (INTEL_REVID(dev) <= SKL_REVID_E0)
 		/* WaDisableLSQCROPERFforOCL:skl */
-		I915_WRITE(GEN8_L3SQCREG4, I915_READ(GEN8_L3SQCREG4) |
-			   GEN8_LQSC_RO_PERF_DIS);
+		WA_SET_BIT(MMIO, GEN8_L3SQCREG4, GEN8_LQSC_RO_PERF_DIS);
 
 	/* WaEnableGapsTsvCreditFix:skl */
 	if (IS_SKYLAKE(dev) && (INTEL_REVID(dev) >= SKL_REVID_C0)) {
-		I915_WRITE(GEN8_GARBCNTL, (I915_READ(GEN8_GARBCNTL) |
-					   GEN9_GAPS_TSV_CREDIT_DISABLE));
+		WA_SET_BIT(MMIO, GEN8_GARBCNTL,
+			   GEN9_GAPS_TSV_CREDIT_DISABLE);
 	}
 }
 
@@ -119,25 +116,23 @@ static void bxt_init_clock_gating(struct drm_device *dev)
 	gen9_init_clock_gating(dev);
 
 	/* WaDisableSDEUnitClockGating:bxt */
-	I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) |
-		   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
+	WA_SET_BIT(MMIO, 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_SET_BIT(MMIO, GEN8_UCGCTL6, GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ);
 
 	/* WaStoreMultiplePTEenable:bxt */
 	/* This is a requirement according to Hardware specification */
 	if (INTEL_REVID(dev) == BXT_REVID_A0)
-		I915_WRITE(TILECTL, I915_READ(TILECTL) | TILECTL_TLBPF);
+		WA_SET_BIT(MMIO, TILECTL, TILECTL_TLBPF);
 
 	/* WaSetClckGatingDisableMedia:bxt */
 	if (INTEL_REVID(dev) == BXT_REVID_A0) {
-		I915_WRITE(GEN7_MISCCPCTL, (I915_READ(GEN7_MISCCPCTL) &
-					    ~GEN8_DOP_CLOCK_GATE_MEDIA_ENABLE));
+		WA_CLR_BIT(MMIO, GEN7_MISCCPCTL,
+			   GEN8_DOP_CLOCK_GATE_MEDIA_ENABLE);
 	}
 }
 
-- 
2.1.4