drm/i915/guc/rc: Setup and enable GuCRC feature

This feature hands over the control of HW RC6 to the GuC.
GuC decides when to put HW into RC6 based on it's internal
busyness algorithms.

GuCRC needs GuC submission to be enabled, and only
supported on Gen12+ for now.

When GuCRC is enabled, do not set HW RC6. Use a H2G message
to tell GuC to enable GuCRC. When disabling RC6, tell GuC to
revert RC6 control back to KMD. KMD is still responsible for
enabling everything related to Coarse Power Gating though.

v2: Address comments (Michal W)
v3: Don't set hysterisis values when GuCRC is used (Matt Roper)
v4: checkpatch()
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730202119.23810-15-vinay.belgaumkar@intel.com

drivers/gpu/drm/i915/Makefile

@@ -186,6 +186,7 @@ i915-y += gt/uc/intel_uc.o \
 	  gt/uc/intel_guc_fw.o \
 	  gt/uc/intel_guc_log.o \
 	  gt/uc/intel_guc_log_debugfs.o \
+	  gt/uc/intel_guc_rc.o \
 	  gt/uc/intel_guc_slpc.o \
 	  gt/uc/intel_guc_submission.o \
 	  gt/uc/intel_huc.o \

drivers/gpu/drm/i915/gt/intel_rc6.c

@@ -62,20 +62,25 @@ static void gen11_rc6_enable(struct intel_rc6 *rc6)
 	u32 pg_enable;
 	int i;
 
-	/* 2b: Program RC6 thresholds.*/
-	set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
-	set(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
+	/*
+	 * With GuCRC, these parameters are set by GuC
+	 */
+	if (!intel_uc_uses_guc_rc(&gt->uc)) {
+		/* 2b: Program RC6 thresholds.*/
+		set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
+		set(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
 
-	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
-	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
-	for_each_engine(engine, rc6_to_gt(rc6), id)
-		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
+		set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
+		set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
+		for_each_engine(engine, rc6_to_gt(rc6), id)
+			set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
 
-	set(uncore, GUC_MAX_IDLE_COUNT, 0xA);
+		set(uncore, GUC_MAX_IDLE_COUNT, 0xA);
 
-	set(uncore, GEN6_RC_SLEEP, 0);
+		set(uncore, GEN6_RC_SLEEP, 0);
 
-	set(uncore, GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
+		set(uncore, GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
+	}
 
 	/*
 	 * 2c: Program Coarse Power Gating Policies.
@@ -98,11 +103,19 @@ static void gen11_rc6_enable(struct intel_rc6 *rc6)
 	set(uncore, GEN9_MEDIA_PG_IDLE_HYSTERESIS, 60);
 	set(uncore, GEN9_RENDER_PG_IDLE_HYSTERESIS, 60);
 
-	/* 3a: Enable RC6 */
-	rc6->ctl_enable =
-		GEN6_RC_CTL_HW_ENABLE |
-		GEN6_RC_CTL_RC6_ENABLE |
-		GEN6_RC_CTL_EI_MODE(1);
+	/* 3a: Enable RC6
+	 *
+	 * With GuCRC, we do not enable bit 31 of RC_CTL,
+	 * thus allowing GuC to control RC6 entry/exit fully instead.
+	 * We will not set the HW ENABLE and EI bits
+	 */
+	if (!intel_guc_rc_enable(&gt->uc.guc))
+		rc6->ctl_enable = GEN6_RC_CTL_RC6_ENABLE;
+	else
+		rc6->ctl_enable =
+			GEN6_RC_CTL_HW_ENABLE |
+			GEN6_RC_CTL_RC6_ENABLE |
+			GEN6_RC_CTL_EI_MODE(1);
 
 	pg_enable =
 		GEN9_RENDER_PG_ENABLE |
@@ -513,6 +526,10 @@ static void __intel_rc6_disable(struct intel_rc6 *rc6)
 {
 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
+	struct intel_gt *gt = rc6_to_gt(rc6);
+
+	/* Take control of RC6 back from GuC */
+	intel_guc_rc_disable(&gt->uc.guc);
 
 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
 	if (GRAPHICS_VER(i915) >= 9)

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

@@ -135,6 +135,7 @@ enum intel_guc_action {
 	INTEL_GUC_ACTION_SET_CONTEXT_PREEMPTION_TIMEOUT = 0x1007,
 	INTEL_GUC_ACTION_CONTEXT_RESET_NOTIFICATION = 0x1008,
 	INTEL_GUC_ACTION_ENGINE_FAILURE_NOTIFICATION = 0x1009,
+	INTEL_GUC_ACTION_SETUP_PC_GUCRC = 0x3004,
 	INTEL_GUC_ACTION_AUTHENTICATE_HUC = 0x4000,
 	INTEL_GUC_ACTION_REGISTER_CONTEXT = 0x4502,
 	INTEL_GUC_ACTION_DEREGISTER_CONTEXT = 0x4503,
@@ -145,6 +146,11 @@ enum intel_guc_action {
 	INTEL_GUC_ACTION_LIMIT
 };
 
+enum intel_guc_rc_options {
+	INTEL_GUCRC_HOST_CONTROL,
+	INTEL_GUCRC_FIRMWARE_CONTROL,
+};
+
 enum intel_guc_preempt_options {
 	INTEL_GUC_PREEMPT_OPTION_DROP_WORK_Q = 0x4,
 	INTEL_GUC_PREEMPT_OPTION_DROP_SUBMIT_Q = 0x8,

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

@@ -159,6 +159,7 @@ void intel_guc_init_early(struct intel_guc *guc)
 	intel_guc_log_init_early(&guc->log);
 	intel_guc_submission_init_early(guc);
 	intel_guc_slpc_init_early(&guc->slpc);
+	intel_guc_rc_init_early(guc);
 
 	mutex_init(&guc->send_mutex);
 	spin_lock_init(&guc->irq_lock);

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

@@ -59,6 +59,8 @@ struct intel_guc {
 
 	bool submission_supported;
 	bool submission_selected;
+	bool rc_supported;
+	bool rc_selected;
 
 	struct i915_vma *ads_vma;
 	struct __guc_ads_blob *ads_blob;

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

+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#include "intel_guc_rc.h"
+#include "gt/intel_gt.h"
+#include "i915_drv.h"
+
+static bool __guc_rc_supported(struct intel_guc *guc)
+{
+	/* GuC RC is unavailable for pre-Gen12 */
+	return guc->submission_supported &&
+		GRAPHICS_VER(guc_to_gt(guc)->i915) >= 12;
+}
+
+static bool __guc_rc_selected(struct intel_guc *guc)
+{
+	if (!intel_guc_rc_is_supported(guc))
+		return false;
+
+	return guc->submission_selected;
+}
+
+void intel_guc_rc_init_early(struct intel_guc *guc)
+{
+	guc->rc_supported = __guc_rc_supported(guc);
+	guc->rc_selected = __guc_rc_selected(guc);
+}
+
+static int guc_action_control_gucrc(struct intel_guc *guc, bool enable)
+{
+	u32 rc_mode = enable ? INTEL_GUCRC_FIRMWARE_CONTROL :
+				INTEL_GUCRC_HOST_CONTROL;
+	u32 action[] = {
+		INTEL_GUC_ACTION_SETUP_PC_GUCRC,
+		rc_mode
+	};
+	int ret;
+
+	ret = intel_guc_send(guc, action, ARRAY_SIZE(action));
+	ret = ret > 0 ? -EPROTO : ret;
+
+	return ret;
+}
+
+static int __guc_rc_control(struct intel_guc *guc, bool enable)
+{
+	struct intel_gt *gt = guc_to_gt(guc);
+	struct drm_device *drm = &guc_to_gt(guc)->i915->drm;
+	int ret;
+
+	if (!intel_uc_uses_guc_rc(&gt->uc))
+		return -EOPNOTSUPP;
+
+	if (!intel_guc_is_ready(guc))
+		return -EINVAL;
+
+	ret = guc_action_control_gucrc(guc, enable);
+	if (ret) {
+		drm_err(drm, "Failed to %s GuC RC (%pe)\n",
+			enabledisable(enable), ERR_PTR(ret));
+		return ret;
+	}
+
+	drm_info(&gt->i915->drm, "GuC RC: %s\n",
+		 enableddisabled(enable));
+
+	return 0;
+}
+
+int intel_guc_rc_enable(struct intel_guc *guc)
+{
+	return __guc_rc_control(guc, true);
+}
+
+int intel_guc_rc_disable(struct intel_guc *guc)
+{
+	return __guc_rc_control(guc, false);
+}

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

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+
+#ifndef _INTEL_GUC_RC_H_
+#define _INTEL_GUC_RC_H_
+
+#include "intel_guc_submission.h"
+
+void intel_guc_rc_init_early(struct intel_guc *guc);
+
+static inline bool intel_guc_rc_is_supported(struct intel_guc *guc)
+{
+	return guc->rc_supported;
+}
+
+static inline bool intel_guc_rc_is_wanted(struct intel_guc *guc)
+{
+	return guc->submission_selected && intel_guc_rc_is_supported(guc);
+}
+
+static inline bool intel_guc_rc_is_used(struct intel_guc *guc)
+{
+	return intel_guc_submission_is_used(guc) && intel_guc_rc_is_wanted(guc);
+}
+
+int intel_guc_rc_enable(struct intel_guc *guc);
+int intel_guc_rc_disable(struct intel_guc *guc);
+
+#endif

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

@@ -7,6 +7,7 @@
 #define _INTEL_UC_H_
 
 #include "intel_guc.h"
+#include "intel_guc_rc.h"
 #include "intel_guc_submission.h"
 #include "intel_guc_slpc.h"
 #include "intel_huc.h"
@@ -85,6 +86,7 @@ uc_state_checkers(guc, guc);
 uc_state_checkers(huc, huc);
 uc_state_checkers(guc, guc_submission);
 uc_state_checkers(guc, guc_slpc);
+uc_state_checkers(guc, guc_rc);
 
 #undef uc_state_checkers
 #undef __uc_state_checker