drm/i915: Extract GT ring management

Although the ring management is much smaller compared to the other GT
power management functions, continue the theme of extracting it out of
the huge intel_pm.c for maintenance.

Based on a patch by Chris Wilson.
Signed-off-by: Andi Shyti <andi.shyti@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191020184139.9145-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/Makefile

@@ -87,6 +87,7 @@ gt-y += \
 	gt/intel_gt_pm_irq.o \
 	gt/intel_gt_requests.o \
 	gt/intel_hangcheck.o \
+	gt/intel_llc.o \
 	gt/intel_lrc.o \
 	gt/intel_rc6.o \
 	gt/intel_renderstate.o \

drivers/gpu/drm/i915/gt/intel_gt_types.h

@@ -17,6 +17,7 @@
 
 #include "i915_vma.h"
 #include "intel_engine_types.h"
+#include "intel_llc_types.h"
 #include "intel_reset_types.h"
 #include "intel_rc6_types.h"
 #include "intel_wakeref.h"
@@ -79,6 +80,7 @@ struct intel_gt {
 	 */
 	intel_wakeref_t awake;
 
+	struct intel_llc llc;
 	struct intel_rc6 rc6;
 
 	struct blocking_notifier_head pm_notifications;

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

+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include <linux/cpufreq.h>
+
+#include "i915_drv.h"
+#include "intel_gt.h"
+#include "intel_llc.h"
+#include "intel_sideband.h"
+
+struct ia_constants {
+	unsigned int min_gpu_freq;
+	unsigned int max_gpu_freq;
+
+	unsigned int min_ring_freq;
+	unsigned int max_ia_freq;
+};
+
+static struct intel_gt *llc_to_gt(struct intel_llc *llc)
+{
+	return container_of(llc, struct intel_gt, llc);
+}
+
+static unsigned int cpu_max_MHz(void)
+{
+	struct cpufreq_policy *policy;
+	unsigned int max_khz;
+
+	policy = cpufreq_cpu_get(0);
+	if (policy) {
+		max_khz = policy->cpuinfo.max_freq;
+		cpufreq_cpu_put(policy);
+	} else {
+		/*
+		 * Default to measured freq if none found, PCU will ensure we
+		 * don't go over
+		 */
+		max_khz = tsc_khz;
+	}
+
+	return max_khz / 1000;
+}
+
+static bool get_ia_constants(struct intel_llc *llc,
+			     struct ia_constants *consts)
+{
+	struct drm_i915_private *i915 = llc_to_gt(llc)->i915;
+	struct intel_rps *rps = &i915->gt_pm.rps;
+
+	if (rps->max_freq <= rps->min_freq)
+		return false;
+
+	consts->max_ia_freq = cpu_max_MHz();
+
+	consts->min_ring_freq =
+		intel_uncore_read(llc_to_gt(llc)->uncore, DCLK) & 0xf;
+	/* convert DDR frequency from units of 266.6MHz to bandwidth */
+	consts->min_ring_freq = mult_frac(consts->min_ring_freq, 8, 3);
+
+	consts->min_gpu_freq = rps->min_freq;
+	consts->max_gpu_freq = rps->max_freq;
+	if (INTEL_GEN(i915) >= 9) {
+		/* Convert GT frequency to 50 HZ units */
+		consts->min_gpu_freq /= GEN9_FREQ_SCALER;
+		consts->max_gpu_freq /= GEN9_FREQ_SCALER;
+	}
+
+	return true;
+}
+
+static void calc_ia_freq(struct intel_llc *llc,
+			 unsigned int gpu_freq,
+			 const struct ia_constants *consts,
+			 unsigned int *out_ia_freq,
+			 unsigned int *out_ring_freq)
+{
+	struct drm_i915_private *i915 = llc_to_gt(llc)->i915;
+	const int diff = consts->max_gpu_freq - gpu_freq;
+	unsigned int ia_freq = 0, ring_freq = 0;
+
+	if (INTEL_GEN(i915) >= 9) {
+		/*
+		 * ring_freq = 2 * GT. ring_freq is in 100MHz units
+		 * No floor required for ring frequency on SKL.
+		 */
+		ring_freq = gpu_freq;
+	} else if (INTEL_GEN(i915) >= 8) {
+		/* max(2 * GT, DDR). NB: GT is 50MHz units */
+		ring_freq = max(consts->min_ring_freq, gpu_freq);
+	} else if (IS_HASWELL(i915)) {
+		ring_freq = mult_frac(gpu_freq, 5, 4);
+		ring_freq = max(consts->min_ring_freq, ring_freq);
+		/* leave ia_freq as the default, chosen by cpufreq */
+	} else {
+		const int min_freq = 15;
+		const int scale = 180;
+
+		/*
+		 * On older processors, there is no separate ring
+		 * clock domain, so in order to boost the bandwidth
+		 * of the ring, we need to upclock the CPU (ia_freq).
+		 *
+		 * For GPU frequencies less than 750MHz,
+		 * just use the lowest ring freq.
+		 */
+		if (gpu_freq < min_freq)
+			ia_freq = 800;
+		else
+			ia_freq = consts->max_ia_freq - diff * scale / 2;
+		ia_freq = DIV_ROUND_CLOSEST(ia_freq, 100);
+	}
+
+	*out_ia_freq = ia_freq;
+	*out_ring_freq = ring_freq;
+}
+
+static void gen6_update_ring_freq(struct intel_llc *llc)
+{
+	struct drm_i915_private *i915 = llc_to_gt(llc)->i915;
+	struct ia_constants consts;
+	unsigned int gpu_freq;
+
+	if (!get_ia_constants(llc, &consts))
+		return;
+
+	/*
+	 * For each potential GPU frequency, load a ring frequency we'd like
+	 * to use for memory access.  We do this by specifying the IA frequency
+	 * the PCU should use as a reference to determine the ring frequency.
+	 */
+	for (gpu_freq = consts.max_gpu_freq;
+	     gpu_freq >= consts.min_gpu_freq;
+	     gpu_freq--) {
+		unsigned int ia_freq, ring_freq;
+
+		calc_ia_freq(llc, gpu_freq, &consts, &ia_freq, &ring_freq);
+		sandybridge_pcode_write(i915,
+					GEN6_PCODE_WRITE_MIN_FREQ_TABLE,
+					ia_freq << GEN6_PCODE_FREQ_IA_RATIO_SHIFT |
+					ring_freq << GEN6_PCODE_FREQ_RING_RATIO_SHIFT |
+					gpu_freq);
+	}
+}
+
+void intel_llc_enable(struct intel_llc *llc)
+{
+	if (HAS_LLC(llc_to_gt(llc)->i915))
+		gen6_update_ring_freq(llc);
+}
+
+void intel_llc_disable(struct intel_llc *llc)
+{
+	/* Currently there is no HW configuration to be done to disable. */
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftest_llc.c"
+#endif

drivers/gpu/drm/i915/gt/intel_llc.h

+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef INTEL_LLC_H
+#define INTEL_LLC_H
+
+struct intel_llc;
+
+void intel_llc_enable(struct intel_llc *llc);
+void intel_llc_disable(struct intel_llc *llc);
+
+#endif /* INTEL_LLC_H */

drivers/gpu/drm/i915/gt/intel_llc_types.h

+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef INTEL_LLC_TYPES_H
+#define INTEL_LLC_TYPES_H
+
+struct intel_llc {
+};
+
+#endif /* INTEL_LLC_TYPES_H */

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

@@ -5,6 +5,8 @@
  * Copyright © 2019 Intel Corporation
  */
 
+#include "selftest_llc.h"
+
 static int live_gt_resume(void *arg)
 {
 	struct intel_gt *gt = arg;
@@ -32,6 +34,13 @@ static int live_gt_resume(void *arg)
 			err = -EINVAL;
 			break;
 		}
+
+		err = st_llc_verify(&gt->llc);
+		if (err) {
+			pr_err("llc state not restored upon resume!\n");
+			intel_gt_set_wedged_on_init(gt);
+			break;
+		}
 	} while (!__igt_timeout(end_time, NULL));
 
 	return err;

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

+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "intel_pm.h" /* intel_gpu_freq() */
+#include "selftest_llc.h"
+
+static int gen6_verify_ring_freq(struct intel_llc *llc)
+{
+	struct drm_i915_private *i915 = llc_to_gt(llc)->i915;
+	struct ia_constants consts;
+	intel_wakeref_t wakeref;
+	unsigned int gpu_freq;
+	int err = 0;
+
+	wakeref = intel_runtime_pm_get(llc_to_gt(llc)->uncore->rpm);
+
+	if (!get_ia_constants(llc, &consts)) {
+		err = -ENODEV;
+		goto out_rpm;
+	}
+
+	for (gpu_freq = consts.min_gpu_freq;
+	     gpu_freq <= consts.max_gpu_freq;
+	     gpu_freq++) {
+		unsigned int ia_freq, ring_freq, found;
+		u32 val;
+
+		calc_ia_freq(llc, gpu_freq, &consts, &ia_freq, &ring_freq);
+
+		val = gpu_freq;
+		if (sandybridge_pcode_read(i915,
+					   GEN6_PCODE_READ_MIN_FREQ_TABLE,
+					   &val, NULL)) {
+			pr_err("Failed to read freq table[%d], range [%d, %d]\n",
+			       gpu_freq, consts.min_gpu_freq, consts.max_gpu_freq);
+			err = -ENXIO;
+			break;
+		}
+
+		found = (val >> 0) & 0xff;
+		if (found != ia_freq) {
+			pr_err("Min freq table(%d/[%d, %d]):%dMHz did not match expected CPU freq, found %d, expected %d\n",
+			       gpu_freq, consts.min_gpu_freq, consts.max_gpu_freq,
+			       intel_gpu_freq(i915, gpu_freq * (INTEL_GEN(i915) >= 9 ? GEN9_FREQ_SCALER : 1)),
+			       found, ia_freq);
+			err = -EINVAL;
+			break;
+		}
+
+		found = (val >> 8) & 0xff;
+		if (found != ring_freq) {
+			pr_err("Min freq table(%d/[%d, %d]):%dMHz did not match expected ring freq, found %d, expected %d\n",
+			       gpu_freq, consts.min_gpu_freq, consts.max_gpu_freq,
+			       intel_gpu_freq(i915, gpu_freq * (INTEL_GEN(i915) >= 9 ? GEN9_FREQ_SCALER : 1)),
+			       found, ring_freq);
+			err = -EINVAL;
+			break;
+		}
+	}
+
+out_rpm:
+	intel_runtime_pm_put(llc_to_gt(llc)->uncore->rpm, wakeref);
+	return err;
+}
+
+int st_llc_verify(struct intel_llc *llc)
+{
+	int err = 0;
+
+	if (HAS_LLC(llc_to_gt(llc)->i915))
+		err = gen6_verify_ring_freq(llc);
+
+	return err;
+}

drivers/gpu/drm/i915/gt/selftest_llc.h

+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef SELFTEST_LLC_H
+#define SELFTEST_LLC_H
+
+struct intel_llc;
+
+int st_llc_verify(struct intel_llc *llc);
+
+#endif /* SELFTEST_LLC_H */

drivers/gpu/drm/i915/i915_drv.h

@@ -605,13 +605,8 @@ struct intel_rps {
 	struct intel_rps_ei ei;
 };
 
-struct intel_llc_pstate {
-	bool enabled;
-};
-
 struct intel_gen6_power_mgmt {
 	struct intel_rps rps;
-	struct intel_llc_pstate llc_pstate;
 };
 
 /* defined intel_pm.c */

drivers/gpu/drm/i915/intel_pm.c

@@ -25,7 +25,6 @@
  *
  */
 
-#include <linux/cpufreq.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
 
@@ -38,6 +37,8 @@
 #include "display/intel_fbc.h"
 #include "display/intel_sprite.h"
 
+#include "gt/intel_llc.h"
+
 #include "i915_drv.h"
 #include "i915_irq.h"
 #include "i915_trace.h"
@@ -7030,93 +7031,6 @@ static void gen6_enable_rps(struct drm_i915_private *dev_priv)
 	intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
 }
 
-static void gen6_update_ring_freq(struct drm_i915_private *dev_priv)
-{
-	struct intel_rps *rps = &dev_priv->gt_pm.rps;
-	const int min_freq = 15;
-	const int scaling_factor = 180;
-	unsigned int gpu_freq;
-	unsigned int max_ia_freq, min_ring_freq;
-	unsigned int max_gpu_freq, min_gpu_freq;
-	struct cpufreq_policy *policy;
-
-	lockdep_assert_held(&rps->lock);
-
-	if (rps->max_freq <= rps->min_freq)
-		return;
-
-	policy = cpufreq_cpu_get(0);
-	if (policy) {
-		max_ia_freq = policy->cpuinfo.max_freq;
-		cpufreq_cpu_put(policy);
-	} else {
-		/*
-		 * Default to measured freq if none found, PCU will ensure we
-		 * don't go over
-		 */
-		max_ia_freq = tsc_khz;
-	}
-
-	/* Convert from kHz to MHz */
-	max_ia_freq /= 1000;
-
-	min_ring_freq = I915_READ(DCLK) & 0xf;
-	/* convert DDR frequency from units of 266.6MHz to bandwidth */
-	min_ring_freq = mult_frac(min_ring_freq, 8, 3);
-
-	min_gpu_freq = rps->min_freq;
-	max_gpu_freq = rps->max_freq;
-	if (IS_GEN9_BC(dev_priv) || INTEL_GEN(dev_priv) >= 10) {
-		/* Convert GT frequency to 50 HZ units */
-		min_gpu_freq /= GEN9_FREQ_SCALER;
-		max_gpu_freq /= GEN9_FREQ_SCALER;
-	}
-
-	/*
-	 * For each potential GPU frequency, load a ring frequency we'd like
-	 * to use for memory access.  We do this by specifying the IA frequency
-	 * the PCU should use as a reference to determine the ring frequency.
-	 */
-	for (gpu_freq = max_gpu_freq; gpu_freq >= min_gpu_freq; gpu_freq--) {
-		const int diff = max_gpu_freq - gpu_freq;
-		unsigned int ia_freq = 0, ring_freq = 0;
-
-		if (IS_GEN9_BC(dev_priv) || INTEL_GEN(dev_priv) >= 10) {
-			/*
-			 * ring_freq = 2 * GT. ring_freq is in 100MHz units
-			 * No floor required for ring frequency on SKL.
-			 */
-			ring_freq = gpu_freq;
-		} else if (INTEL_GEN(dev_priv) >= 8) {
-			/* max(2 * GT, DDR). NB: GT is 50MHz units */
-			ring_freq = max(min_ring_freq, gpu_freq);
-		} else if (IS_HASWELL(dev_priv)) {
-			ring_freq = mult_frac(gpu_freq, 5, 4);
-			ring_freq = max(min_ring_freq, ring_freq);
-			/* leave ia_freq as the default, chosen by cpufreq */
-		} else {
-			/* On older processors, there is no separate ring
-			 * clock domain, so in order to boost the bandwidth
-			 * of the ring, we need to upclock the CPU (ia_freq).
-			 *
-			 * For GPU frequencies less than 750MHz,
-			 * just use the lowest ring freq.
-			 */
-			if (gpu_freq < min_freq)
-				ia_freq = 800;
-			else
-				ia_freq = max_ia_freq - ((diff * scaling_factor) / 2);
-			ia_freq = DIV_ROUND_CLOSEST(ia_freq, 100);
-		}
-
-		sandybridge_pcode_write(dev_priv,
-					GEN6_PCODE_WRITE_MIN_FREQ_TABLE,
-					ia_freq << GEN6_PCODE_FREQ_IA_RATIO_SHIFT |
-					ring_freq << GEN6_PCODE_FREQ_RING_RATIO_SHIFT |
-					gpu_freq);
-	}
-}
-
 static int cherryview_rps_max_freq(struct drm_i915_private *dev_priv)
 {
 	u32 val, rp0;
@@ -7965,18 +7879,6 @@ void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv)
 		gen6_reset_rps_interrupts(dev_priv);
 }
 
-static inline void intel_disable_llc_pstate(struct drm_i915_private *i915)
-{
-	lockdep_assert_held(&i915->gt_pm.rps.lock);
-
-	if (!i915->gt_pm.llc_pstate.enabled)
-		return;
-
-	/* Currently there is no HW configuration to be done to disable. */
-
-	i915->gt_pm.llc_pstate.enabled = false;
-}
-
 static void intel_disable_rps(struct drm_i915_private *dev_priv)
 {
 	lockdep_assert_held(&dev_priv->gt_pm.rps.lock);
@@ -8004,23 +7906,11 @@ void intel_disable_gt_powersave(struct drm_i915_private *dev_priv)
 
 	intel_disable_rps(dev_priv);
 	if (HAS_LLC(dev_priv))
-		intel_disable_llc_pstate(dev_priv);
+		intel_llc_disable(&dev_priv->gt.llc);
 
 	mutex_unlock(&dev_priv->gt_pm.rps.lock);
 }
 
-static inline void intel_enable_llc_pstate(struct drm_i915_private *i915)
-{
-	lockdep_assert_held(&i915->gt_pm.rps.lock);
-
-	if (i915->gt_pm.llc_pstate.enabled)
-		return;
-
-	gen6_update_ring_freq(i915);
-
-	i915->gt_pm.llc_pstate.enabled = true;
-}
-
 static void intel_enable_rps(struct drm_i915_private *dev_priv)
 {
 	struct intel_rps *rps = &dev_priv->gt_pm.rps;
@@ -8064,8 +7954,8 @@ void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
 
 	if (HAS_RPS(dev_priv))
 		intel_enable_rps(dev_priv);
-	if (HAS_LLC(dev_priv))
-		intel_enable_llc_pstate(dev_priv);
+
+	intel_llc_enable(&dev_priv->gt.llc);
 
 	mutex_unlock(&dev_priv->gt_pm.rps.lock);
 }