drm/i915: Rename and comment all the RPS *stuff*

The names of the struct members for RPS are stupid. Every time I need to
do anything in this code I have to spend a significant amount of time to
remember what it all means. By renaming the variables (and adding the
comments) I hope to clear up the situation. Indeed doing this make some
upcoming patches more readable.

I've avoided ILK because it's possible that the naming used for Ironlake
matches what is in the docs. I believe the ILK power docs were never
published, and I am too lazy to dig them up.

v2: leave rp0, and rp1 in the names. It is useful to have these limits
available at times. min_freq and max_freq (which may be equal to rp0, or
rp1 depending on the platform) represent the actual HW min and max.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 60 insertions, 58 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index dd631d19b2b..3db7c40cc9a 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2907,9 +2907,9 @@ static u32 gen6_rps_limits(struct drm_i915_private *dev_priv, u8 val)
 	 * the hw runs at the minimal clock before selecting the desired
 	 * frequency, if the down threshold expires in that window we will not
 	 * receive a down interrupt. */
-	limits = dev_priv->rps.max_delay << 24;
-	if (val <= dev_priv->rps.min_delay)
-		limits |= dev_priv->rps.min_delay << 16;
+	limits = dev_priv->rps.max_freq_softlimit << 24;
+	if (val <= dev_priv->rps.min_freq_softlimit)
+		limits |= dev_priv->rps.min_freq_softlimit << 16;
 
 	return limits;
 }
@@ -2921,26 +2921,26 @@ static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
 	new_power = dev_priv->rps.power;
 	switch (dev_priv->rps.power) {
 	case LOW_POWER:
-		if (val > dev_priv->rps.rpe_delay + 1 && val > dev_priv->rps.cur_delay)
+		if (val > dev_priv->rps.efficient_freq + 1 && val > dev_priv->rps.cur_freq)
 			new_power = BETWEEN;
 		break;
 
 	case BETWEEN:
-		if (val <= dev_priv->rps.rpe_delay && val < dev_priv->rps.cur_delay)
+		if (val <= dev_priv->rps.efficient_freq && val < dev_priv->rps.cur_freq)
 			new_power = LOW_POWER;
-		else if (val >= dev_priv->rps.rp0_delay && val > dev_priv->rps.cur_delay)
+		else if (val >= dev_priv->rps.rp0_freq && val > dev_priv->rps.cur_freq)
 			new_power = HIGH_POWER;
 		break;
 
 	case HIGH_POWER:
-		if (val < (dev_priv->rps.rp1_delay + dev_priv->rps.rp0_delay) >> 1 && val < dev_priv->rps.cur_delay)
+		if (val < (dev_priv->rps.rp1_freq + dev_priv->rps.rp0_freq) >> 1 && val < dev_priv->rps.cur_freq)
 			new_power = BETWEEN;
 		break;
 	}
 	/* Max/min bins are special */
-	if (val == dev_priv->rps.min_delay)
+	if (val == dev_priv->rps.min_freq_softlimit)
 		new_power = LOW_POWER;
-	if (val == dev_priv->rps.max_delay)
+	if (val == dev_priv->rps.max_freq_softlimit)
 		new_power = HIGH_POWER;
 	if (new_power == dev_priv->rps.power)
 		return;
@@ -3014,10 +3014,10 @@ void gen6_set_rps(struct drm_device *dev, u8 val)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
-	WARN_ON(val > dev_priv->rps.max_delay);
-	WARN_ON(val < dev_priv->rps.min_delay);
+	WARN_ON(val > dev_priv->rps.max_freq_softlimit);
+	WARN_ON(val < dev_priv->rps.min_freq_softlimit);
 
-	if (val == dev_priv->rps.cur_delay) {
+	if (val == dev_priv->rps.cur_freq) {
 		/* min/max delay may still have been modified so be sure to
 		 * write the limits value */
 		I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
@@ -3045,7 +3045,7 @@ void gen6_set_rps(struct drm_device *dev, u8 val)
 
 	POSTING_READ(GEN6_RPNSWREQ);
 
-	dev_priv->rps.cur_delay = val;
+	dev_priv->rps.cur_freq = val;
 
 	trace_intel_gpu_freq_change(val * 50);
 }
@@ -3065,7 +3065,7 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
 	 * When we are idle.  Drop to min voltage state.
 	 */
 
-	if (dev_priv->rps.cur_delay <= dev_priv->rps.min_delay)
+	if (dev_priv->rps.cur_freq <= dev_priv->rps.min_freq_softlimit)
 		return;
 
 	/* Mask turbo interrupt so that they will not come in between */
@@ -3082,10 +3082,10 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
 		return;
 	}
 
-	dev_priv->rps.cur_delay = dev_priv->rps.min_delay;
+	dev_priv->rps.cur_freq = dev_priv->rps.min_freq_softlimit;
 
 	vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ,
-					dev_priv->rps.min_delay);
+					dev_priv->rps.min_freq_softlimit);
 
 	if (wait_for(((vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS))
 				& GENFREQSTATUS) == 0, 5))
@@ -3099,7 +3099,7 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
 	/* Unmask Up interrupts */
 	dev_priv->rps.rp_up_masked = true;
 	gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
-						dev_priv->rps.min_delay);
+						dev_priv->rps.min_freq_softlimit);
 }
 
 void gen6_rps_idle(struct drm_i915_private *dev_priv)
@@ -3111,7 +3111,7 @@ void gen6_rps_idle(struct drm_i915_private *dev_priv)
 		if (IS_VALLEYVIEW(dev))
 			vlv_set_rps_idle(dev_priv);
 		else
-			gen6_set_rps(dev_priv->dev, dev_priv->rps.min_delay);
+			gen6_set_rps(dev_priv->dev, dev_priv->rps.min_freq_softlimit);
 		dev_priv->rps.last_adj = 0;
 	}
 	mutex_unlock(&dev_priv->rps.hw_lock);
@@ -3124,9 +3124,9 @@ void gen6_rps_boost(struct drm_i915_private *dev_priv)
 	mutex_lock(&dev_priv->rps.hw_lock);
 	if (dev_priv->rps.enabled) {
 		if (IS_VALLEYVIEW(dev))
-			valleyview_set_rps(dev_priv->dev, dev_priv->rps.max_delay);
+			valleyview_set_rps(dev_priv->dev, dev_priv->rps.max_freq_softlimit);
 		else
-			gen6_set_rps(dev_priv->dev, dev_priv->rps.max_delay);
+			gen6_set_rps(dev_priv->dev, dev_priv->rps.max_freq_softlimit);
 		dev_priv->rps.last_adj = 0;
 	}
 	mutex_unlock(&dev_priv->rps.hw_lock);
@@ -3137,20 +3137,20 @@ void valleyview_set_rps(struct drm_device *dev, u8 val)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
-	WARN_ON(val > dev_priv->rps.max_delay);
-	WARN_ON(val < dev_priv->rps.min_delay);
+	WARN_ON(val > dev_priv->rps.max_freq_softlimit);
+	WARN_ON(val < dev_priv->rps.min_freq_softlimit);
 
 	DRM_DEBUG_DRIVER("GPU freq request from %d MHz (%u) to %d MHz (%u)\n",
-			 vlv_gpu_freq(dev_priv, dev_priv->rps.cur_delay),
-			 dev_priv->rps.cur_delay,
+			 vlv_gpu_freq(dev_priv, dev_priv->rps.cur_freq),
+			 dev_priv->rps.cur_freq,
 			 vlv_gpu_freq(dev_priv, val), val);
 
-	if (val == dev_priv->rps.cur_delay)
+	if (val == dev_priv->rps.cur_freq)
 		return;
 
 	vlv_punit_write(dev_priv, PUNIT_REG_GPU_FREQ_REQ, val);
 
-	dev_priv->rps.cur_delay = val;
+	dev_priv->rps.cur_freq = val;
 
 	trace_intel_gpu_freq_change(vlv_gpu_freq(dev_priv, val));
 }
@@ -3292,8 +3292,8 @@ static void gen8_enable_rps(struct drm_device *dev)
 
 	/* Docs recommend 900MHz, and 300 MHz respectively */
 	I915_WRITE(GEN6_RP_INTERRUPT_LIMITS,
-		   dev_priv->rps.max_delay << 24 |
-		   dev_priv->rps.min_delay << 16);
+		   dev_priv->rps.max_freq_softlimit << 24 |
+		   dev_priv->rps.min_freq_softlimit << 16);
 
 	I915_WRITE(GEN6_RP_UP_THRESHOLD, 7600000 / 128); /* 76ms busyness per EI, 90% */
 	I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 31300000 / 128); /* 313ms busyness per EI, 70%*/
@@ -3352,20 +3352,22 @@ static void gen6_enable_rps(struct drm_device *dev)
 	rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
 	gt_perf_status = I915_READ(GEN6_GT_PERF_STATUS);
 
-	/* In units of 50MHz */
-	dev_priv->rps.hw_max = hw_max = rp_state_cap & 0xff;
+	/* All of these values are in units of 50MHz */
+	dev_priv->rps.cur_freq = 0;
+	/* hw_max = RP0 until we check for overclocking */
+	dev_priv->rps.max_freq = hw_max = rp_state_cap & 0xff;
+	/* static values from HW: RP0 < RPe < RP1 < RPn (min_freq) */
+	dev_priv->rps.rp1_freq = (rp_state_cap >>  8) & 0xff;
+	dev_priv->rps.rp0_freq = (rp_state_cap >>  0) & 0xff;
+	dev_priv->rps.efficient_freq = dev_priv->rps.rp1_freq;
 	dev_priv->rps.min_freq = hw_min = (rp_state_cap >> 16) & 0xff;
-	dev_priv->rps.rp1_delay = (rp_state_cap >>  8) & 0xff;
-	dev_priv->rps.rp0_delay = (rp_state_cap >>  0) & 0xff;
-	dev_priv->rps.rpe_delay = dev_priv->rps.rp1_delay;
-	dev_priv->rps.cur_delay = 0;
 
 	/* Preserve min/max settings in case of re-init */
-	if (dev_priv->rps.max_delay == 0)
-		dev_priv->rps.max_delay = hw_max;
+	if (dev_priv->rps.max_freq_softlimit == 0)
+		dev_priv->rps.max_freq_softlimit = hw_max;
 
-	if (dev_priv->rps.min_delay == 0)
-		dev_priv->rps.min_delay = hw_min;
+	if (dev_priv->rps.min_freq_softlimit == 0)
+		dev_priv->rps.min_freq_softlimit = hw_min;
 
 	/* disable the counters and set deterministic thresholds */
 	I915_WRITE(GEN6_RC_CONTROL, 0);
@@ -3420,13 +3422,13 @@ static void gen6_enable_rps(struct drm_device *dev)
 	ret = sandybridge_pcode_read(dev_priv, GEN6_READ_OC_PARAMS, &pcu_mbox);
 	if (!ret && (pcu_mbox & (1<<31))) { /* OC supported */
 		DRM_DEBUG_DRIVER("Overclocking supported. Max: %dMHz, Overclock max: %dMHz\n",
-				 (dev_priv->rps.max_delay & 0xff) * 50,
+				 (dev_priv->rps.max_freq_softlimit & 0xff) * 50,
 				 (pcu_mbox & 0xff) * 50);
-		dev_priv->rps.hw_max = pcu_mbox & 0xff;
+		dev_priv->rps.max_freq = pcu_mbox & 0xff;
 	}
 
 	dev_priv->rps.power = HIGH_POWER; /* force a reset */
-	gen6_set_rps(dev_priv->dev, dev_priv->rps.min_delay);
+	gen6_set_rps(dev_priv->dev, dev_priv->rps.min_freq_softlimit);
 
 	gen6_enable_rps_interrupts(dev);
 
@@ -3482,9 +3484,9 @@ void gen6_update_ring_freq(struct drm_device *dev)
 	 * 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 = dev_priv->rps.max_delay; gpu_freq >= dev_priv->rps.min_delay;
+	for (gpu_freq = dev_priv->rps.max_freq_softlimit; gpu_freq >= dev_priv->rps.min_freq_softlimit;
 	     gpu_freq--) {
-		int diff = dev_priv->rps.max_delay - gpu_freq;
+		int diff = dev_priv->rps.max_freq_softlimit - gpu_freq;
 		unsigned int ia_freq = 0, ring_freq = 0;
 
 		if (INTEL_INFO(dev)->gen >= 8) {
@@ -3650,20 +3652,20 @@ static void valleyview_enable_rps(struct drm_device *dev)
 	DRM_DEBUG_DRIVER("GPLL enabled? %s\n", val & 0x10 ? "yes" : "no");
 	DRM_DEBUG_DRIVER("GPU status: 0x%08x\n", val);
 
-	dev_priv->rps.cur_delay = (val >> 8) & 0xff;
+	dev_priv->rps.cur_freq = (val >> 8) & 0xff;
 	DRM_DEBUG_DRIVER("current GPU freq: %d MHz (%u)\n",
-			 vlv_gpu_freq(dev_priv, dev_priv->rps.cur_delay),
-			 dev_priv->rps.cur_delay);
+			 vlv_gpu_freq(dev_priv, dev_priv->rps.cur_freq),
+			 dev_priv->rps.cur_freq);
 
-	dev_priv->rps.hw_max = hw_max = valleyview_rps_max_freq(dev_priv);
+	dev_priv->rps.max_freq = hw_max = valleyview_rps_max_freq(dev_priv);
 	DRM_DEBUG_DRIVER("max GPU freq: %d MHz (%u)\n",
 			 vlv_gpu_freq(dev_priv, hw_max),
 			 hw_max);
 
-	dev_priv->rps.rpe_delay = valleyview_rps_rpe_freq(dev_priv);
+	dev_priv->rps.efficient_freq = valleyview_rps_rpe_freq(dev_priv);
 	DRM_DEBUG_DRIVER("RPe GPU freq: %d MHz (%u)\n",
-			 vlv_gpu_freq(dev_priv, dev_priv->rps.rpe_delay),
-			 dev_priv->rps.rpe_delay);
+			 vlv_gpu_freq(dev_priv, dev_priv->rps.efficient_freq),
+			 dev_priv->rps.efficient_freq);
 
 	hw_min = valleyview_rps_min_freq(dev_priv);
 	DRM_DEBUG_DRIVER("min GPU freq: %d MHz (%u)\n",
@@ -3671,17 +3673,17 @@ static void valleyview_enable_rps(struct drm_device *dev)
 			 hw_min);
 
 	/* Preserve min/max settings in case of re-init */
-	if (dev_priv->rps.max_delay == 0)
-		dev_priv->rps.max_delay = hw_max;
+	if (dev_priv->rps.max_freq_softlimit == 0)
+		dev_priv->rps.max_freq_softlimit = hw_max;
 
-	if (dev_priv->rps.min_delay == 0)
-		dev_priv->rps.min_delay = hw_min;
+	if (dev_priv->rps.min_freq_softlimit == 0)
+		dev_priv->rps.min_freq_softlimit = hw_min;
 
 	DRM_DEBUG_DRIVER("setting GPU freq to %d MHz (%u)\n",
-			 vlv_gpu_freq(dev_priv, dev_priv->rps.rpe_delay),
-			 dev_priv->rps.rpe_delay);
+			 vlv_gpu_freq(dev_priv, dev_priv->rps.efficient_freq),
+			 dev_priv->rps.efficient_freq);
 
-	valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
+	valleyview_set_rps(dev_priv->dev, dev_priv->rps.efficient_freq);
 
 	dev_priv->rps.rp_up_masked = false;
 	dev_priv->rps.rp_down_masked = false;
@@ -4122,7 +4124,7 @@ static unsigned long __i915_gfx_val(struct drm_i915_private *dev_priv)
 
 	assert_spin_locked(&mchdev_lock);
 
-	pxvid = I915_READ(PXVFREQ_BASE + (dev_priv->rps.cur_delay * 4));
+	pxvid = I915_READ(PXVFREQ_BASE + (dev_priv->rps.cur_freq * 4));
 	pxvid = (pxvid >> 24) & 0x7f;
 	ext_v = pvid_to_extvid(dev_priv, pxvid);