drm/i915: Assert that runtime pm is active on user fw access

On user forcewake access, assert that runtime pm reference is held.
Fix and cleanup the callsites accordingly.

v2: Remove intel_runtime_pm_get() rebasehap (Deepak)

v3: use drivers own runtime state tracking as pm_runtime_active()
    will return wrong results when we are in resume callchain (Mika)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

4 files changed, 30 insertions, 120 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 7952f31..ac517eb 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -4339,6 +4339,7 @@ static int i915_forcewake_open(struct inode *inode, struct file *file)
 	if (INTEL_INFO(dev)->gen < 6)
 		return 0;
 
+	intel_runtime_pm_get(dev_priv);
 	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
 
 	return 0;
@@ -4353,6 +4354,7 @@ static int i915_forcewake_release(struct inode *inode, struct file *file)
 		return 0;
 
 	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
+	intel_runtime_pm_put(dev_priv);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c5cbcd7..61b123f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7870,19 +7870,8 @@ static void hsw_restore_lcpll(struct drm_i915_private *dev_priv)
 	/*
 	 * Make sure we're not on PC8 state before disabling PC8, otherwise
 	 * we'll hang the machine. To prevent PC8 state, just enable force_wake.
-	 *
-	 * The other problem is that hsw_restore_lcpll() is called as part of
-	 * the runtime PM resume sequence, so we can't just call
-	 * gen6_gt_force_wake_get() because that function calls
-	 * intel_runtime_pm_get(), and we can't change the runtime PM refcount
-	 * while we are on the resume sequence. So to solve this problem we have
-	 * to call special forcewake code that doesn't touch runtime PM and
-	 * doesn't enable the forcewake delayed work.
 	 */
-	spin_lock_irq(&dev_priv->uncore.lock);
-	if (dev_priv->uncore.forcewake_count++ == 0)
-		dev_priv->uncore.funcs.force_wake_get(dev_priv, FORCEWAKE_ALL);
-	spin_unlock_irq(&dev_priv->uncore.lock);
+	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
 
 	if (val & LCPLL_POWER_DOWN_ALLOW) {
 		val &= ~LCPLL_POWER_DOWN_ALLOW;
@@ -7912,11 +7901,7 @@ static void hsw_restore_lcpll(struct drm_i915_private *dev_priv)
 			DRM_ERROR("Switching back to LCPLL failed\n");
 	}
 
-	/* See the big comment above. */
-	spin_lock_irq(&dev_priv->uncore.lock);
-	if (--dev_priv->uncore.forcewake_count == 0)
-		dev_priv->uncore.funcs.force_wake_put(dev_priv, FORCEWAKE_ALL);
-	spin_unlock_irq(&dev_priv->uncore.lock);
+	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
 }
 
 /*
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index a5f614d..49c7d86 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -283,7 +283,6 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	uint64_t temp = 0;
 	uint32_t desc[4];
-	unsigned long flags;
 
 	/* XXX: You must always write both descriptors in the order below. */
 	if (ctx_obj1)
@@ -297,63 +296,17 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
 	desc[3] = (u32)(temp >> 32);
 	desc[2] = (u32)temp;
 
-	/* Set Force Wakeup bit to prevent GT from entering C6 while ELSP writes
-	 * are in progress.
-	 *
-	 * The other problem is that we can't just call gen6_gt_force_wake_get()
-	 * because that function calls intel_runtime_pm_get(), which might sleep.
-	 * Instead, we do the runtime_pm_get/put when creating/destroying requests.
-	 */
-	spin_lock_irqsave(&dev_priv->uncore.lock, flags);
-	if (IS_CHERRYVIEW(dev) || INTEL_INFO(dev)->gen >= 9) {
-		if (dev_priv->uncore.fw_rendercount++ == 0)
-			dev_priv->uncore.funcs.force_wake_get(dev_priv,
-							      FORCEWAKE_RENDER);
-		if (dev_priv->uncore.fw_mediacount++ == 0)
-			dev_priv->uncore.funcs.force_wake_get(dev_priv,
-							      FORCEWAKE_MEDIA);
-		if (INTEL_INFO(dev)->gen >= 9) {
-			if (dev_priv->uncore.fw_blittercount++ == 0)
-				dev_priv->uncore.funcs.force_wake_get(dev_priv,
-							FORCEWAKE_BLITTER);
-		}
-	} else {
-		if (dev_priv->uncore.forcewake_count++ == 0)
-			dev_priv->uncore.funcs.force_wake_get(dev_priv,
-							      FORCEWAKE_ALL);
-	}
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, flags);
-
+	gen6_gt_force_wake_get(dev_priv, FORCEWAKE_ALL);
 	I915_WRITE(RING_ELSP(ring), desc[1]);
 	I915_WRITE(RING_ELSP(ring), desc[0]);
 	I915_WRITE(RING_ELSP(ring), desc[3]);
+
 	/* The context is automatically loaded after the following */
 	I915_WRITE(RING_ELSP(ring), desc[2]);
 
 	/* ELSP is a wo register, so use another nearby reg for posting instead */
 	POSTING_READ(RING_EXECLIST_STATUS(ring));
-
-	/* Release Force Wakeup (see the big comment above). */
-	spin_lock_irqsave(&dev_priv->uncore.lock, flags);
-	if (IS_CHERRYVIEW(dev) || INTEL_INFO(dev)->gen >= 9) {
-		if (--dev_priv->uncore.fw_rendercount == 0)
-			dev_priv->uncore.funcs.force_wake_put(dev_priv,
-							      FORCEWAKE_RENDER);
-		if (--dev_priv->uncore.fw_mediacount == 0)
-			dev_priv->uncore.funcs.force_wake_put(dev_priv,
-							      FORCEWAKE_MEDIA);
-		if (INTEL_INFO(dev)->gen >= 9) {
-			if (--dev_priv->uncore.fw_blittercount == 0)
-				dev_priv->uncore.funcs.force_wake_put(dev_priv,
-							FORCEWAKE_BLITTER);
-		}
-	} else {
-		if (--dev_priv->uncore.forcewake_count == 0)
-			dev_priv->uncore.funcs.force_wake_put(dev_priv,
-							      FORCEWAKE_ALL);
-	}
-
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, flags);
+	gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
 }
 
 static int execlists_update_context(struct drm_i915_gem_object *ctx_obj,
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index b39ed79..974881e 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -24,6 +24,8 @@
 #include "i915_drv.h"
 #include "intel_drv.h"
 
+#include <linux/pm_runtime.h>
+
 #define FORCEWAKE_ACK_TIMEOUT_MS 2
 
 #define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__))
@@ -247,10 +249,6 @@ static void __vlv_force_wake_put(struct drm_i915_private *dev_priv,
 
 static void vlv_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
 {
-	unsigned long irqflags;
-
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
-
 	if (fw_engine & FORCEWAKE_RENDER &&
 	    dev_priv->uncore.fw_rendercount++ != 0)
 		fw_engine &= ~FORCEWAKE_RENDER;
@@ -260,16 +258,10 @@ static void vlv_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
 
 	if (fw_engine)
 		dev_priv->uncore.funcs.force_wake_get(dev_priv, fw_engine);
-
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
 static void vlv_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 {
-	unsigned long irqflags;
-
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
-
 	if (fw_engine & FORCEWAKE_RENDER) {
 		WARN_ON(!dev_priv->uncore.fw_rendercount);
 		if (--dev_priv->uncore.fw_rendercount != 0)
@@ -284,8 +276,6 @@ static void vlv_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 
 	if (fw_engine)
 		dev_priv->uncore.funcs.force_wake_put(dev_priv, fw_engine);
-
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
 static void __gen9_gt_force_wake_mt_reset(struct drm_i915_private *dev_priv)
@@ -380,10 +370,6 @@ __gen9_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 static void
 gen9_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
 {
-	unsigned long irqflags;
-
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
-
 	if (FORCEWAKE_RENDER & fw_engine) {
 		if (dev_priv->uncore.fw_rendercount++ == 0)
 			dev_priv->uncore.funcs.force_wake_get(dev_priv,
@@ -401,17 +387,11 @@ gen9_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
 			dev_priv->uncore.funcs.force_wake_get(dev_priv,
 							FORCEWAKE_BLITTER);
 	}
-
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
 static void
 gen9_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 {
-	unsigned long irqflags;
-
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
-
 	if (FORCEWAKE_RENDER & fw_engine) {
 		WARN_ON(dev_priv->uncore.fw_rendercount == 0);
 		if (--dev_priv->uncore.fw_rendercount == 0)
@@ -432,8 +412,6 @@ gen9_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 			dev_priv->uncore.funcs.force_wake_put(dev_priv,
 							FORCEWAKE_BLITTER);
 	}
-
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
 static void gen6_force_wake_timer(unsigned long arg)
@@ -562,19 +540,20 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
 	if (!dev_priv->uncore.funcs.force_wake_get)
 		return;
 
-	intel_runtime_pm_get(dev_priv);
+	WARN_ON(dev_priv->pm.suspended);
 
-	/* Redirect to Gen9 specific routine */
-	if (IS_GEN9(dev_priv->dev))
-		return gen9_force_wake_get(dev_priv, fw_engine);
+	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
-	/* Redirect to VLV specific routine */
-	if (IS_VALLEYVIEW(dev_priv->dev))
-		return vlv_force_wake_get(dev_priv, fw_engine);
+	if (IS_GEN9(dev_priv->dev)) {
+		gen9_force_wake_get(dev_priv, fw_engine);
+	} else if (IS_VALLEYVIEW(dev_priv->dev)) {
+		vlv_force_wake_get(dev_priv, fw_engine);
+	} else {
+		if (dev_priv->uncore.forcewake_count++ == 0)
+			dev_priv->uncore.funcs.force_wake_get(dev_priv,
+							      FORCEWAKE_ALL);
+	}
 
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
-	if (dev_priv->uncore.forcewake_count++ == 0)
-		dev_priv->uncore.funcs.force_wake_get(dev_priv, FORCEWAKE_ALL);
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
@@ -588,31 +567,22 @@ void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 	if (!dev_priv->uncore.funcs.force_wake_put)
 		return;
 
-	/* Redirect to Gen9 specific routine */
+	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
+
 	if (IS_GEN9(dev_priv->dev)) {
 		gen9_force_wake_put(dev_priv, fw_engine);
-		goto out;
-	}
-
-	/* Redirect to VLV specific routine */
-	if (IS_VALLEYVIEW(dev_priv->dev)) {
+	} else if (IS_VALLEYVIEW(dev_priv->dev)) {
 		vlv_force_wake_put(dev_priv, fw_engine);
-		goto out;
-	}
-
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
-	WARN_ON(!dev_priv->uncore.forcewake_count);
-
-	if (--dev_priv->uncore.forcewake_count == 0) {
-		dev_priv->uncore.forcewake_count++;
-		mod_timer_pinned(&dev_priv->uncore.force_wake_timer,
-				 jiffies + 1);
+	} else {
+		WARN_ON(!dev_priv->uncore.forcewake_count);
+		if (--dev_priv->uncore.forcewake_count == 0) {
+			dev_priv->uncore.forcewake_count++;
+			mod_timer_pinned(&dev_priv->uncore.force_wake_timer,
+					 jiffies + 1);
+		}
 	}
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
-
-out:
-	intel_runtime_pm_put(dev_priv);
 }
 
 void assert_force_wake_inactive(struct drm_i915_private *dev_priv)