[PATCH 03/10] drm/i915/chv: Enable Render Standby (RC6) for Cheeryview

[deepak.s@linux.intel.com]

From: Deepak S <deepak.s@linux.intel.com>

v2: Configure PCBR if BIOS fails allocate pcbr (deepak)

v3: Fix PCBR condition check during CHV RC6 Enable flag set

Signed-off-by: Deepak S <deepak.s@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h |   1 +
 drivers/gpu/drm/i915/intel_pm.c | 100 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b951d61..7090b42 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5134,6 +5134,7 @@ enum punit_power_well {
 #define GEN6_GT_GFX_RC6				0x138108
 #define GEN6_GT_GFX_RC6p			0x13810C
 #define GEN6_GT_GFX_RC6pp			0x138110
+#define VLV_PCBR_ADDR_SHIFT			12
 
 #define GEN6_PCODE_MAILBOX			0x138124
 #define   GEN6_PCODE_READY			(1<<31)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f3c5bce..421a4cc 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3264,6 +3264,18 @@ static void gen6_disable_rps(struct drm_device *dev)
 		gen6_disable_rps_interrupts(dev);
 }
 
+static void cherryview_disable_rps(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	I915_WRITE(GEN6_RC_CONTROL, 0);
+
+	if (dev_priv->vlv_pctx) {
+		drm_gem_object_unreference(&dev_priv->vlv_pctx->base);
+		dev_priv->vlv_pctx = NULL;
+	}
+}
+
 static void valleyview_disable_rps(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3642,6 +3654,28 @@ static void valleyview_check_pctx(struct drm_i915_private *dev_priv)
 			     dev_priv->vlv_pctx->stolen->start);
 }
 
+static void cherryview_setup_pctx(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long pctx_paddr;
+	struct i915_gtt *gtt = &dev_priv->gtt;
+	u32 pcbr;
+	int pctx_size = 32*1024;
+
+	pcbr = I915_READ(VLV_PCBR);
+	if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
+		/*
+		 * From the Gunit register HAS:
+		 * The Gfx driver is expected to program this register and ensure
+		 * proper allocation within Gfx stolen memory.  For example, this
+		 * register should be programmed such than the PCBR range does not
+		 * overlap with other relevant ranges.
+		 */
+		pctx_paddr = (dev_priv->mm.stolen_base + gtt->stolen_size - pctx_size);
+		I915_WRITE(VLV_PCBR, pctx_paddr);
+	}
+}
+
 static void valleyview_setup_pctx(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3697,6 +3731,61 @@ static void valleyview_cleanup_pctx(struct drm_device *dev)
 	dev_priv->vlv_pctx = NULL;
 }
 
+static void cherryview_enable_rps(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_ring_buffer *ring;
+	u32 gtfifodbg, rc6_mode = 0, pcbr;
+	int i;
+
+	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
+
+	if ((gtfifodbg = I915_READ(GTFIFODBG))) {
+		DRM_DEBUG_DRIVER("GT fifo had a previous error %x\n",
+				 gtfifodbg);
+		I915_WRITE(GTFIFODBG, gtfifodbg);
+	}
+
+	cherryview_setup_pctx(dev);
+
+	/* 1a & 1b: Get forcewake during program sequence. Although the driver
+	 * hasn't enabled a state yet where we need forcewake, BIOS may have.*/
+	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
+
+	/* 2a: Program RC6 thresholds.*/
+	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
+	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
+	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
+
+	for_each_ring(ring, dev_priv, i)
+		I915_WRITE(RING_MAX_IDLE(ring->mmio_base), 10);
+
+	I915_WRITE(GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
+
+	/* allows RC6 residency counter to work */
+	I915_WRITE(VLV_COUNTER_CONTROL,
+		   _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
+				      VLV_MEDIA_RC6_COUNT_EN |
+				      VLV_RENDER_RC6_COUNT_EN));
+
+	/* Todo: If BIOS has not configured PCBR
+	 *       then allocate in BIOS Reserved */
+
+	/* For now we assume BIOS is allocating and populating the PCBR  */
+	pcbr = I915_READ(VLV_PCBR);
+
+	DRM_DEBUG_DRIVER("PCBR offset : 0x%x\n", pcbr);
+
+	/* 3: Enable RC6 */
+	if ((intel_enable_rc6(dev) & INTEL_RC6_ENABLE) &&
+						(pcbr >> VLV_PCBR_ADDR_SHIFT))
+		rc6_mode = GEN6_RC_CTL_EI_MODE(1) | VLV_RC_CTL_CTX_RST_PARALLEL;
+
+	I915_WRITE(GEN6_RC_CONTROL, rc6_mode);
+
+	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
+}
+
 static void valleyview_enable_rps(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -4550,7 +4639,9 @@ void intel_disable_gt_powersave(struct drm_device *dev)
 		cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work);
 		cancel_work_sync(&dev_priv->rps.work);
 		mutex_lock(&dev_priv->rps.hw_lock);
-		if (IS_VALLEYVIEW(dev))
+		if (IS_CHERRYVIEW(dev))
+			cherryview_disable_rps(dev);
+		else if (IS_VALLEYVIEW(dev))
 			valleyview_disable_rps(dev);
 		else
 			gen6_disable_rps(dev);
@@ -4568,7 +4659,9 @@ static void intel_gen6_powersave_work(struct work_struct *work)
 
 	mutex_lock(&dev_priv->rps.hw_lock);
 
-	if (IS_VALLEYVIEW(dev)) {
+	if (IS_CHERRYVIEW(dev)) {
+		cherryview_enable_rps(dev);
+	} else if (IS_VALLEYVIEW(dev)) {
 		valleyview_enable_rps(dev);
 	} else if (IS_BROADWELL(dev)) {
 		gen8_enable_rps(dev);
@@ -4590,6 +4683,8 @@ void intel_enable_gt_powersave(struct drm_device *dev)
 		ironlake_enable_rc6(dev);
 		intel_init_emon(dev);
 	} else if (IS_GEN6(dev) || IS_GEN7(dev)) {
+		if (IS_VALLEYVIEW(dev))
+			valleyview_setup_pctx(dev);
 		/*
 		 * PCU communication is slow and this doesn't need to be
 		 * done at any specific time, so do this out of our fast path
@@ -5175,6 +5270,7 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 		dev_priv->mem_freq = 1333;
 		break;
 	}
+
 	DRM_DEBUG_DRIVER("DDR speed: %d MHz", dev_priv->mem_freq);
 
 	dev_priv->vlv_cdclk_freq = valleyview_cur_cdclk(dev_priv);
-- 
1.9.1