drm/i915: Define a separate variable and control for RPS waitboost frequency

To allow the user finer control over waitboosting, allow them to set the
frequency we request for the boost. This also them allows to effectively
disable the boosting by setting the boost request to a low frequency.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1468397438-21226-5-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -1381,6 +1381,8 @@ static int i915_frequency_info(struct seq_file *m, void *unused)
 			   intel_gpu_freq(dev_priv, dev_priv->rps.idle_freq));
 		seq_printf(m, "Min freq: %d MHz\n",
 			   intel_gpu_freq(dev_priv, dev_priv->rps.min_freq));
+		seq_printf(m, "Boost freq: %d MHz\n",
+			   intel_gpu_freq(dev_priv, dev_priv->rps.boost_freq));
 		seq_printf(m, "Max freq: %d MHz\n",
 			   intel_gpu_freq(dev_priv, dev_priv->rps.max_freq));
 		seq_printf(m,

drivers/gpu/drm/i915/i915_drv.h

@@ -1170,6 +1170,7 @@ struct intel_gen6_power_mgmt {
 	u8 max_freq_softlimit;	/* Max frequency permitted by the driver */
 	u8 max_freq;		/* Maximum frequency, RP0 if not overclocking */
 	u8 min_freq;		/* AKA RPn. Minimum frequency */
+	u8 boost_freq;		/* Frequency to request when wait boosting */
 	u8 idle_freq;		/* Frequency to request when we are idle */
 	u8 efficient_freq;	/* AKA RPe. Pre-determined balanced frequency */
 	u8 rp1_freq;		/* "less than" RP0 power/freqency */

drivers/gpu/drm/i915/i915_irq.c

@@ -1105,9 +1105,10 @@ static void gen6_pm_rps_work(struct work_struct *work)
 	new_delay = dev_priv->rps.cur_freq;
 	min = dev_priv->rps.min_freq_softlimit;
 	max = dev_priv->rps.max_freq_softlimit;
-
-	if (client_boost) {
-		new_delay = dev_priv->rps.max_freq_softlimit;
+	if (client_boost || any_waiters(dev_priv))
+		max = dev_priv->rps.max_freq;
+	if (client_boost && new_delay < dev_priv->rps.boost_freq) {
+		new_delay = dev_priv->rps.boost_freq;
 		adj = 0;
 	} else if (pm_iir & GEN6_PM_RP_UP_THRESHOLD) {
 		if (adj > 0)
@@ -1122,7 +1123,7 @@ static void gen6_pm_rps_work(struct work_struct *work)
 			new_delay = dev_priv->rps.efficient_freq;
 			adj = 0;
 		}
-	} else if (any_waiters(dev_priv)) {
+	} else if (client_boost || any_waiters(dev_priv)) {
 		adj = 0;
 	} else if (pm_iir & GEN6_PM_RP_DOWN_TIMEOUT) {
 		if (dev_priv->rps.cur_freq > dev_priv->rps.efficient_freq)

drivers/gpu/drm/i915/i915_sysfs.c

@@ -318,6 +318,41 @@ static ssize_t gt_cur_freq_mhz_show(struct device *kdev,
 	return snprintf(buf, PAGE_SIZE, "%d\n", ret);
 }
 
+static ssize_t gt_boost_freq_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf)
+{
+	struct drm_minor *minor = dev_to_drm_minor(kdev);
+	struct drm_i915_private *dev_priv = to_i915(minor->dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n",
+			intel_gpu_freq(dev_priv, dev_priv->rps.boost_freq));
+}
+
+static ssize_t gt_boost_freq_mhz_store(struct device *kdev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t count)
+{
+	struct drm_minor *minor = dev_to_drm_minor(kdev);
+	struct drm_device *dev = minor->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 val;
+	ssize_t ret;
+
+	ret = kstrtou32(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	/* Validate against (static) hardware limits */
+	val = intel_freq_opcode(dev_priv, val);
+	if (val < dev_priv->rps.min_freq || val > dev_priv->rps.max_freq)
+		return -EINVAL;
+
+	mutex_lock(&dev_priv->rps.hw_lock);
+	dev_priv->rps.boost_freq = val;
+	mutex_unlock(&dev_priv->rps.hw_lock);
+
+	return count;
+}
+
 static ssize_t vlv_rpe_freq_mhz_show(struct device *kdev,
 				     struct device_attribute *attr, char *buf)
 {
@@ -465,6 +500,7 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
 
 static DEVICE_ATTR(gt_act_freq_mhz, S_IRUGO, gt_act_freq_mhz_show, NULL);
 static DEVICE_ATTR(gt_cur_freq_mhz, S_IRUGO, gt_cur_freq_mhz_show, NULL);
+static DEVICE_ATTR(gt_boost_freq_mhz, S_IRUGO, gt_boost_freq_mhz_show, gt_boost_freq_mhz_store);
 static DEVICE_ATTR(gt_max_freq_mhz, S_IRUGO | S_IWUSR, gt_max_freq_mhz_show, gt_max_freq_mhz_store);
 static DEVICE_ATTR(gt_min_freq_mhz, S_IRUGO | S_IWUSR, gt_min_freq_mhz_show, gt_min_freq_mhz_store);
 
@@ -498,6 +534,7 @@ static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr
 static const struct attribute *gen6_attrs[] = {
 	&dev_attr_gt_act_freq_mhz.attr,
 	&dev_attr_gt_cur_freq_mhz.attr,
+	&dev_attr_gt_boost_freq_mhz.attr,
 	&dev_attr_gt_max_freq_mhz.attr,
 	&dev_attr_gt_min_freq_mhz.attr,
 	&dev_attr_gt_RP0_freq_mhz.attr,
@@ -509,6 +546,7 @@ static const struct attribute *gen6_attrs[] = {
 static const struct attribute *vlv_attrs[] = {
 	&dev_attr_gt_act_freq_mhz.attr,
 	&dev_attr_gt_cur_freq_mhz.attr,
+	&dev_attr_gt_boost_freq_mhz.attr,
 	&dev_attr_gt_max_freq_mhz.attr,
 	&dev_attr_gt_min_freq_mhz.attr,
 	&dev_attr_gt_RP0_freq_mhz.attr,

drivers/gpu/drm/i915/intel_pm.c

@@ -4911,7 +4911,7 @@ void gen6_rps_boost(struct drm_i915_private *dev_priv,
 	 */
 	if (!(dev_priv->gt.awake &&
 	      dev_priv->rps.enabled &&
-	      dev_priv->rps.cur_freq < dev_priv->rps.max_freq_softlimit))
+	      dev_priv->rps.cur_freq < dev_priv->rps.boost_freq))
 		return;
 
 	/* Force a RPS boost (and don't count it against the client) if
@@ -6532,6 +6532,9 @@ void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
 		}
 	}
 
+	/* Finally allow us to boost to max by default */
+	dev_priv->rps.boost_freq = dev_priv->rps.max_freq;
+
 	mutex_unlock(&dev_priv->rps.hw_lock);
 }