drm/i915/guc: Support OA when Wa_16011777198 is enabled

On DG2, a w/a resets RCS/CCS before it goes into RC6. This breaks OA
since OA does not expect engine resets during its use. Fix it by
disabling RC6.

v2: (Ashutosh)
- Bring back slpc_unset_param helper
- Update commit msg
- Use with_intel_runtime_pm helper for set/unset

v3: (Ashutosh)
- Just use intel_uc_uses_guc_rc
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026222102.5526-15-umesh.nerlige.ramappa@intel.com

drivers/gpu/drm/i915/gt/uc/abi/guc_actions_slpc_abi.h

@@ -128,6 +128,15 @@ enum slpc_media_ratio_mode {
 	SLPC_MEDIA_RATIO_MODE_FIXED_ONE_TO_TWO = 2,
 };
 
+enum slpc_gucrc_mode {
+	SLPC_GUCRC_MODE_HW = 0,
+	SLPC_GUCRC_MODE_GUCRC_NO_RC6 = 1,
+	SLPC_GUCRC_MODE_GUCRC_STATIC_TIMEOUT = 2,
+	SLPC_GUCRC_MODE_GUCRC_DYNAMIC_HYSTERESIS = 3,
+
+	SLPC_GUCRC_MODE_MAX,
+};
+
 enum slpc_event_id {
 	SLPC_EVENT_RESET = 0,
 	SLPC_EVENT_SHUTDOWN = 1,

drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c

@@ -137,6 +137,17 @@ static int guc_action_slpc_set_param(struct intel_guc *guc, u8 id, u32 value)
 	return ret > 0 ? -EPROTO : ret;
 }
 
+static int guc_action_slpc_unset_param(struct intel_guc *guc, u8 id)
+{
+	u32 request[] = {
+		GUC_ACTION_HOST2GUC_PC_SLPC_REQUEST,
+		SLPC_EVENT(SLPC_EVENT_PARAMETER_UNSET, 1),
+		id,
+	};
+
+	return intel_guc_send(guc, request, ARRAY_SIZE(request));
+}
+
 static bool slpc_is_running(struct intel_guc_slpc *slpc)
 {
 	return slpc_get_state(slpc) == SLPC_GLOBAL_STATE_RUNNING;
@@ -190,6 +201,15 @@ static int slpc_set_param(struct intel_guc_slpc *slpc, u8 id, u32 value)
 	return ret;
 }
 
+static int slpc_unset_param(struct intel_guc_slpc *slpc, u8 id)
+{
+	struct intel_guc *guc = slpc_to_guc(slpc);
+
+	GEM_BUG_ON(id >= SLPC_MAX_PARAM);
+
+	return guc_action_slpc_unset_param(guc, id);
+}
+
 static int slpc_force_min_freq(struct intel_guc_slpc *slpc, u32 freq)
 {
 	struct drm_i915_private *i915 = slpc_to_i915(slpc);
@@ -644,6 +664,52 @@ static void slpc_get_rp_values(struct intel_guc_slpc *slpc)
 		slpc->boost_freq = slpc->rp0_freq;
 }
 
+/**
+ * intel_guc_slpc_override_gucrc_mode() - override GUCRC mode
+ * @slpc: pointer to intel_guc_slpc.
+ * @mode: new value of the mode.
+ *
+ * This function will override the GUCRC mode.
+ *
+ * Return: 0 on success, non-zero error code on failure.
+ */
+int intel_guc_slpc_override_gucrc_mode(struct intel_guc_slpc *slpc, u32 mode)
+{
+	int ret;
+	struct drm_i915_private *i915 = slpc_to_i915(slpc);
+	intel_wakeref_t wakeref;
+
+	if (mode >= SLPC_GUCRC_MODE_MAX)
+		return -EINVAL;
+
+	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
+		ret = slpc_set_param(slpc, SLPC_PARAM_PWRGATE_RC_MODE, mode);
+		if (ret)
+			drm_err(&i915->drm,
+				"Override gucrc mode %d failed %d\n",
+				mode, ret);
+	}
+
+	return ret;
+}
+
+int intel_guc_slpc_unset_gucrc_mode(struct intel_guc_slpc *slpc)
+{
+	struct drm_i915_private *i915 = slpc_to_i915(slpc);
+	intel_wakeref_t wakeref;
+	int ret = 0;
+
+	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
+		ret = slpc_unset_param(slpc, SLPC_PARAM_PWRGATE_RC_MODE);
+		if (ret)
+			drm_err(&i915->drm,
+				"Unsetting gucrc mode failed %d\n",
+				ret);
+	}
+
+	return ret;
+}
+
 /*
  * intel_guc_slpc_enable() - Start SLPC
  * @slpc: pointer to intel_guc_slpc.

drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h

@@ -44,5 +44,7 @@ int intel_guc_slpc_set_media_ratio_mode(struct intel_guc_slpc *slpc, u32 val);
 void intel_guc_pm_intrmsk_enable(struct intel_gt *gt);
 void intel_guc_slpc_boost(struct intel_guc_slpc *slpc);
 void intel_guc_slpc_dec_waiters(struct intel_guc_slpc *slpc);
+int intel_guc_slpc_unset_gucrc_mode(struct intel_guc_slpc *slpc);
+int intel_guc_slpc_override_gucrc_mode(struct intel_guc_slpc *slpc, u32 mode);
 
 #endif

drivers/gpu/drm/i915/i915_perf.c

@@ -209,6 +209,7 @@
 #include "gt/intel_lrc.h"
 #include "gt/intel_lrc_reg.h"
 #include "gt/intel_ring.h"
+#include "gt/uc/intel_guc_slpc.h"
 
 #include "i915_drv.h"
 #include "i915_file_private.h"
@@ -1582,6 +1583,15 @@ static void i915_oa_stream_destroy(struct i915_perf_stream *stream)
 
 	free_oa_buffer(stream);
 
+	/*
+	 * Wa_16011777198:dg2: Unset the override of GUCRC mode to enable rc6.
+	 */
+	if (intel_uc_uses_guc_rc(&gt->uc) &&
+	    (IS_DG2_GRAPHICS_STEP(gt->i915, G10, STEP_A0, STEP_C0) ||
+	     IS_DG2_GRAPHICS_STEP(gt->i915, G11, STEP_A0, STEP_B0)))
+		drm_WARN_ON(&gt->i915->drm,
+			    intel_guc_slpc_unset_gucrc_mode(&gt->uc.guc.slpc));
+
 	intel_uncore_forcewake_put(stream->uncore, FORCEWAKE_ALL);
 	intel_engine_pm_put(stream->engine);
 
@@ -3265,6 +3275,23 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
 	intel_engine_pm_get(stream->engine);
 	intel_uncore_forcewake_get(stream->uncore, FORCEWAKE_ALL);
 
+	/*
+	 * Wa_16011777198:dg2: GuC resets render as part of the Wa. This causes
+	 * OA to lose the configuration state. Prevent this by overriding GUCRC
+	 * mode.
+	 */
+	if (intel_uc_uses_guc_rc(&gt->uc) &&
+	    (IS_DG2_GRAPHICS_STEP(gt->i915, G10, STEP_A0, STEP_C0) ||
+	     IS_DG2_GRAPHICS_STEP(gt->i915, G11, STEP_A0, STEP_B0))) {
+		ret = intel_guc_slpc_override_gucrc_mode(&gt->uc.guc.slpc,
+							 SLPC_GUCRC_MODE_GUCRC_NO_RC6);
+		if (ret) {
+			drm_dbg(&stream->perf->i915->drm,
+				"Unable to override gucrc mode\n");
+			goto err_config;
+		}
+	}
+
 	ret = alloc_oa_buffer(stream);
 	if (ret)
 		goto err_oa_buf_alloc;