drm/i915: Add Wa_14010733141

The WA requires the following procedure for VDBox SFC reset:

If (MFX-SFC usage is 1) {
	1.Issue a MFX-SFC forced lock
	2.Wait for MFX-SFC forced lock ack
	3.Check the MFX-SFC usage bit
	If (MFX-SFC usage bit is 1)
		Reset VDBOX and SFC
	else
		Reset VDBOX
	Release the force lock MFX-SFC
}
else if(HCP+SFC usage is 1) {
	1.Issue a VE-SFC forced lock
	2.Wait for SFC forced lock ack
	3.Check the VE-SFC usage bit
	If (VE-SFC usage bit is 1)
		Reset VDBOX
	else
		Reset VDBOX and SFC
	Release the force lock VE-SFC.
}
else
	Reset VDBOX

- Restructure: the changes to the original code flow should stay
  relatively minimal; we only need to do an extra HCP check after the
  usual VD-MFX check and, if true, switch the register/bit we're
  performing the lock on.(MattR)

v2:
- Assign unlock mask using paired_engine->mask instead of using
  BIT(paired_vecs->id). (Daniele)

Bspec: 52890, 53509

Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
Co-developed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210526094852.286424-2-aditya.swarup@intel.com

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -338,106 +338,170 @@ static int gen6_reset_engines(struct intel_gt *gt,
 	return gen6_hw_domain_reset(gt, hw_mask);
 }
 
-static int gen11_lock_sfc(struct intel_engine_cs *engine, u32 *hw_mask)
+static struct intel_engine_cs *find_sfc_paired_vecs_engine(struct intel_engine_cs *engine)
+{
+	int vecs_id;
+
+	GEM_BUG_ON(engine->class != VIDEO_DECODE_CLASS);
+
+	vecs_id = _VECS((engine->instance) / 2);
+
+	return engine->gt->engine[vecs_id];
+}
+
+struct sfc_lock_data {
+	i915_reg_t lock_reg;
+	i915_reg_t ack_reg;
+	i915_reg_t usage_reg;
+	u32 lock_bit;
+	u32 ack_bit;
+	u32 usage_bit;
+	u32 reset_bit;
+};
+
+static void get_sfc_forced_lock_data(struct intel_engine_cs *engine,
+				     struct sfc_lock_data *sfc_lock)
+{
+	switch (engine->class) {
+	default:
+		MISSING_CASE(engine->class);
+		fallthrough;
+	case VIDEO_DECODE_CLASS:
+		sfc_lock->lock_reg = GEN11_VCS_SFC_FORCED_LOCK(engine);
+		sfc_lock->lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
+
+		sfc_lock->ack_reg = GEN11_VCS_SFC_LOCK_STATUS(engine);
+		sfc_lock->ack_bit  = GEN11_VCS_SFC_LOCK_ACK_BIT;
+
+		sfc_lock->usage_reg = GEN11_VCS_SFC_LOCK_STATUS(engine);
+		sfc_lock->usage_bit = GEN11_VCS_SFC_USAGE_BIT;
+		sfc_lock->reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
+
+		break;
+	case VIDEO_ENHANCEMENT_CLASS:
+		sfc_lock->lock_reg = GEN11_VECS_SFC_FORCED_LOCK(engine);
+		sfc_lock->lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
+
+		sfc_lock->ack_reg = GEN11_VECS_SFC_LOCK_ACK(engine);
+		sfc_lock->ack_bit  = GEN11_VECS_SFC_LOCK_ACK_BIT;
+
+		sfc_lock->usage_reg = GEN11_VECS_SFC_USAGE(engine);
+		sfc_lock->usage_bit = GEN11_VECS_SFC_USAGE_BIT;
+		sfc_lock->reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
+
+		break;
+	}
+}
+
+static int gen11_lock_sfc(struct intel_engine_cs *engine,
+			  u32 *reset_mask,
+			  u32 *unlock_mask)
 {
 	struct intel_uncore *uncore = engine->uncore;
 	u8 vdbox_sfc_access = engine->gt->info.vdbox_sfc_access;
-	i915_reg_t sfc_forced_lock, sfc_forced_lock_ack;
-	u32 sfc_forced_lock_bit, sfc_forced_lock_ack_bit;
-	i915_reg_t sfc_usage;
-	u32 sfc_usage_bit;
-	u32 sfc_reset_bit;
+	struct sfc_lock_data sfc_lock;
+	bool lock_obtained, lock_to_other = false;
 	int ret;
 
 	switch (engine->class) {
 	case VIDEO_DECODE_CLASS:
 		if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
 			return 0;
 
-		sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
-
-		sfc_forced_lock_ack = GEN11_VCS_SFC_LOCK_STATUS(engine);
-		sfc_forced_lock_ack_bit  = GEN11_VCS_SFC_LOCK_ACK_BIT;
+		fallthrough;
+	case VIDEO_ENHANCEMENT_CLASS:
+		get_sfc_forced_lock_data(engine, &sfc_lock);
 
-		sfc_usage = GEN11_VCS_SFC_LOCK_STATUS(engine);
-		sfc_usage_bit = GEN11_VCS_SFC_USAGE_BIT;
-		sfc_reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
 		break;
+	default:
+		return 0;
+	}
 
-	case VIDEO_ENHANCEMENT_CLASS:
-		sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
+	if (!(intel_uncore_read_fw(uncore, sfc_lock.usage_reg) & sfc_lock.usage_bit)) {
+		struct intel_engine_cs *paired_vecs;
 
-		sfc_forced_lock_ack = GEN11_VECS_SFC_LOCK_ACK(engine);
-		sfc_forced_lock_ack_bit  = GEN11_VECS_SFC_LOCK_ACK_BIT;
+		if (engine->class != VIDEO_DECODE_CLASS ||
+		    !IS_GEN(engine->i915, 12))
+			return 0;
 
-		sfc_usage = GEN11_VECS_SFC_USAGE(engine);
-		sfc_usage_bit = GEN11_VECS_SFC_USAGE_BIT;
-		sfc_reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
-		break;
+		/*
+		 * Wa_14010733141
+		 *
+		 * If the VCS-MFX isn't using the SFC, we also need to check
+		 * whether VCS-HCP is using it.  If so, we need to issue a *VE*
+		 * forced lock on the VE engine that shares the same SFC.
+		 */
+		if (!(intel_uncore_read_fw(uncore,
+					   GEN12_HCP_SFC_LOCK_STATUS(engine)) &
+		      GEN12_HCP_SFC_USAGE_BIT))
+			return 0;
 
-	default:
-		return 0;
+		paired_vecs = find_sfc_paired_vecs_engine(engine);
+		get_sfc_forced_lock_data(paired_vecs, &sfc_lock);
+		lock_to_other = true;
+		*unlock_mask |= paired_vecs->mask;
+	} else {
+		*unlock_mask |= engine->mask;
 	}
 
 	/*
-	 * If the engine is using a SFC, tell the engine that a software reset
+	 * If the engine is using an SFC, tell the engine that a software reset
 	 * is going to happen. The engine will then try to force lock the SFC.
 	 * If SFC ends up being locked to the engine we want to reset, we have
 	 * to reset it as well (we will unlock it once the reset sequence is
 	 * completed).
 	 */
-	if (!(intel_uncore_read_fw(uncore, sfc_usage) & sfc_usage_bit))
-		return 0;
-
-	rmw_set_fw(uncore, sfc_forced_lock, sfc_forced_lock_bit);
+	rmw_set_fw(uncore, sfc_lock.lock_reg, sfc_lock.lock_bit);
 
 	ret = __intel_wait_for_register_fw(uncore,
-					   sfc_forced_lock_ack,
-					   sfc_forced_lock_ack_bit,
-					   sfc_forced_lock_ack_bit,
+					   sfc_lock.ack_reg,
+					   sfc_lock.ack_bit,
+					   sfc_lock.ack_bit,
 					   1000, 0, NULL);
 
-	/* Was the SFC released while we were trying to lock it? */
-	if (!(intel_uncore_read_fw(uncore, sfc_usage) & sfc_usage_bit))
+	/*
+	 * Was the SFC released while we were trying to lock it?
+	 *
+	 * We should reset both the engine and the SFC if:
+	 *  - We were locking the SFC to this engine and the lock succeeded
+	 *       OR
+	 *  - We were locking the SFC to a different engine (Wa_14010733141)
+	 *    but the SFC was released before the lock was obtained.
+	 *
+	 * Otherwise we need only reset the engine by itself and we can
+	 * leave the SFC alone.
+	 */
+	lock_obtained = (intel_uncore_read_fw(uncore, sfc_lock.usage_reg) &
+			sfc_lock.usage_bit) != 0;
+	if (lock_obtained == lock_to_other)
 		return 0;
 
 	if (ret) {
 		ENGINE_TRACE(engine, "Wait for SFC forced lock ack failed\n");
 		return ret;
 	}
 
-	*hw_mask |= sfc_reset_bit;
+	*reset_mask |= sfc_lock.reset_bit;
 	return 0;
 }
 
 static void gen11_unlock_sfc(struct intel_engine_cs *engine)
 {
 	struct intel_uncore *uncore = engine->uncore;
 	u8 vdbox_sfc_access = engine->gt->info.vdbox_sfc_access;
-	i915_reg_t sfc_forced_lock;
-	u32 sfc_forced_lock_bit;
-
-	switch (engine->class) {
-	case VIDEO_DECODE_CLASS:
-		if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
-			return;
-
-		sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
-		break;
+	struct sfc_lock_data sfc_lock = {};
 
-	case VIDEO_ENHANCEMENT_CLASS:
-		sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
-		break;
+	if (engine->class != VIDEO_DECODE_CLASS &&
+	    engine->class != VIDEO_ENHANCEMENT_CLASS)
+		return;
 
-	default:
+	if (engine->class == VIDEO_DECODE_CLASS &&
+	    (BIT(engine->instance) & vdbox_sfc_access) == 0)
 		return;
-	}
 
-	rmw_clear_fw(uncore, sfc_forced_lock, sfc_forced_lock_bit);
+	get_sfc_forced_lock_data(engine, &sfc_lock);
+
+	rmw_clear_fw(uncore, sfc_lock.lock_reg, sfc_lock.lock_bit);
 }
 
 static int gen11_reset_engines(struct intel_gt *gt,
@@ -456,34 +520,38 @@ static int gen11_reset_engines(struct intel_gt *gt,
 	};
 	struct intel_engine_cs *engine;
 	intel_engine_mask_t tmp;
-	u32 hw_mask;
+	u32 reset_mask, unlock_mask = 0;
 	int ret;
 
 	if (engine_mask == ALL_ENGINES) {
-		hw_mask = GEN11_GRDOM_FULL;
+		reset_mask = GEN11_GRDOM_FULL;
 	} else {
-		hw_mask = 0;
+		reset_mask = 0;
 		for_each_engine_masked(engine, gt, engine_mask, tmp) {
 			GEM_BUG_ON(engine->id >= ARRAY_SIZE(hw_engine_mask));
-			hw_mask |= hw_engine_mask[engine->id];
-			ret = gen11_lock_sfc(engine, &hw_mask);
+			reset_mask |= hw_engine_mask[engine->id];
+			ret = gen11_lock_sfc(engine, &reset_mask, &unlock_mask);
 			if (ret)
 				goto sfc_unlock;
 		}
 	}
 
-	ret = gen6_hw_domain_reset(gt, hw_mask);
+	ret = gen6_hw_domain_reset(gt, reset_mask);
 
 sfc_unlock:
 	/*
 	 * We unlock the SFC based on the lock status and not the result of
 	 * gen11_lock_sfc to make sure that we clean properly if something
 	 * wrong happened during the lock (e.g. lock acquired after timeout
 	 * expiration).
+	 *
+	 * Due to Wa_14010733141, we may have locked an SFC to an engine that
+	 * wasn't being reset.  So instead of calling gen11_unlock_sfc()
+	 * on engine_mask, we instead call it on the mask of engines that our
+	 * gen11_lock_sfc() calls told us actually had locks attempted.
 	 */
-	if (engine_mask != ALL_ENGINES)
-		for_each_engine_masked(engine, gt, engine_mask, tmp)
-			gen11_unlock_sfc(engine);
+	for_each_engine_masked(engine, gt, unlock_mask, tmp)
+		gen11_unlock_sfc(engine);
 
 	return ret;
 }

drivers/gpu/drm/i915/i915_reg.h

@@ -416,6 +416,12 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define GEN11_VECS_SFC_USAGE(engine)		_MMIO((engine)->mmio_base + 0x2014)
 #define   GEN11_VECS_SFC_USAGE_BIT		(1 << 0)
 
+#define GEN12_HCP_SFC_FORCED_LOCK(engine)	_MMIO((engine)->mmio_base + 0x2910)
+#define   GEN12_HCP_SFC_FORCED_LOCK_BIT		REG_BIT(0)
+#define GEN12_HCP_SFC_LOCK_STATUS(engine)	_MMIO((engine)->mmio_base + 0x2914)
+#define   GEN12_HCP_SFC_LOCK_ACK_BIT		REG_BIT(1)
+#define   GEN12_HCP_SFC_USAGE_BIT			REG_BIT(0)
+
 #define GEN12_SFC_DONE(n)		_MMIO(0x1cc00 + (n) * 0x100)
 #define GEN12_SFC_DONE_MAX		4