drm/i915: Only save and restore fences for UMS

With KMS, we can simply relinquish the fence when we idle the GPU and
reassign it upon first use.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_gem.c

@@ -1905,11 +1905,22 @@ static void i915_gem_reset_ring_lists(struct drm_i915_private *dev_priv,
 	}
 }
 
+static void i915_gem_reset_fences(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i];
+		if (reg->obj)
+			i915_gem_clear_fence_reg(reg->obj);
+	}
+}
+
 void i915_gem_reset(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj;
-	int i;
 
 	i915_gem_reset_ring_lists(dev_priv, &dev_priv->render_ring);
 	i915_gem_reset_ring_lists(dev_priv, &dev_priv->bsd_ring);
@@ -1940,15 +1951,7 @@ void i915_gem_reset(struct drm_device *dev)
 	}
 
 	/* The fence registers are invalidated so clear them out */
-	for (i = 0; i < 16; i++) {
-		struct drm_i915_fence_reg *reg;
-
-		reg = &dev_priv->fence_regs[i];
-		if (!reg->obj)
-			continue;
-
-		i915_gem_clear_fence_reg(reg->obj);
-	}
+	i915_gem_reset_fences(dev);
 }
 
 /**
@@ -4706,6 +4709,8 @@ i915_gem_idle(struct drm_device *dev)
 		}
 	}
 
+	i915_gem_reset_fences(dev);
+
 	/* Hack!  Don't let anybody do execbuf while we don't control the chip.
 	 * We need to replace this with a semaphore, or something.
 	 * And not confound mm.suspended!

drivers/gpu/drm/i915/i915_suspend.c

@@ -235,6 +235,7 @@ static void i915_restore_vga(struct drm_device *dev)
 static void i915_save_modeset_reg(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	int i;
 
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return;
@@ -367,6 +368,28 @@ static void i915_save_modeset_reg(struct drm_device *dev)
 	}
 	i915_save_palette(dev, PIPE_B);
 	dev_priv->savePIPEBSTAT = I915_READ(PIPEBSTAT);
+
+	/* Fences */
+	switch (INTEL_INFO(dev)->gen) {
+	case 6:
+		for (i = 0; i < 16; i++)
+			dev_priv->saveFENCE[i] = I915_READ64(FENCE_REG_SANDYBRIDGE_0 + (i * 8));
+		break;
+	case 5:
+	case 4:
+		for (i = 0; i < 16; i++)
+			dev_priv->saveFENCE[i] = I915_READ64(FENCE_REG_965_0 + (i * 8));
+		break;
+	case 3:
+		if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
+			for (i = 0; i < 8; i++)
+				dev_priv->saveFENCE[i+8] = I915_READ(FENCE_REG_945_8 + (i * 4));
+	case 2:
+		for (i = 0; i < 8; i++)
+			dev_priv->saveFENCE[i] = I915_READ(FENCE_REG_830_0 + (i * 4));
+		break;
+	}
+
 	return;
 }
 
@@ -375,10 +398,33 @@ static void i915_restore_modeset_reg(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int dpll_a_reg, fpa0_reg, fpa1_reg;
 	int dpll_b_reg, fpb0_reg, fpb1_reg;
+	int i;
 
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return;
 
+	/* Fences */
+	switch (INTEL_INFO(dev)->gen) {
+	case 6:
+		for (i = 0; i < 16; i++)
+			I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + (i * 8), dev_priv->saveFENCE[i]);
+		break;
+	case 5:
+	case 4:
+		for (i = 0; i < 16; i++)
+			I915_WRITE64(FENCE_REG_965_0 + (i * 8), dev_priv->saveFENCE[i]);
+		break;
+	case 3:
+	case 2:
+		if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
+			for (i = 0; i < 8; i++)
+				I915_WRITE(FENCE_REG_945_8 + (i * 4), dev_priv->saveFENCE[i+8]);
+		for (i = 0; i < 8; i++)
+			I915_WRITE(FENCE_REG_830_0 + (i * 4), dev_priv->saveFENCE[i]);
+		break;
+	}
+
+
 	if (HAS_PCH_SPLIT(dev)) {
 		dpll_a_reg = PCH_DPLL_A;
 		dpll_b_reg = PCH_DPLL_B;
@@ -788,28 +834,6 @@ int i915_save_state(struct drm_device *dev)
 	for (i = 0; i < 3; i++)
 		dev_priv->saveSWF2[i] = I915_READ(SWF30 + (i << 2));
 
-	/* Fences */
-	switch (INTEL_INFO(dev)->gen) {
-	case 6:
-		for (i = 0; i < 16; i++)
-			dev_priv->saveFENCE[i] = I915_READ64(FENCE_REG_SANDYBRIDGE_0 + (i * 8));
-		break;
-	case 5:
-	case 4:
-		for (i = 0; i < 16; i++)
-			dev_priv->saveFENCE[i] = I915_READ64(FENCE_REG_965_0 + (i * 8));
-		break;
-	case 3:
-		if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
-			for (i = 0; i < 8; i++)
-				dev_priv->saveFENCE[i+8] = I915_READ(FENCE_REG_945_8 + (i * 4));
-	case 2:
-		for (i = 0; i < 8; i++)
-			dev_priv->saveFENCE[i] = I915_READ(FENCE_REG_830_0 + (i * 4));
-		break;
-
-	}
-
 	return 0;
 }
 
@@ -823,27 +847,6 @@ int i915_restore_state(struct drm_device *dev)
 	/* Hardware status page */
 	I915_WRITE(HWS_PGA, dev_priv->saveHWS);
 
-	/* Fences */
-	switch (INTEL_INFO(dev)->gen) {
-	case 6:
-		for (i = 0; i < 16; i++)
-			I915_WRITE64(FENCE_REG_SANDYBRIDGE_0 + (i * 8), dev_priv->saveFENCE[i]);
-		break;
-	case 5:
-	case 4:
-		for (i = 0; i < 16; i++)
-			I915_WRITE64(FENCE_REG_965_0 + (i * 8), dev_priv->saveFENCE[i]);
-		break;
-	case 3:
-	case 2:
-		if (IS_I945G(dev) || IS_I945GM(dev) || IS_G33(dev))
-			for (i = 0; i < 8; i++)
-				I915_WRITE(FENCE_REG_945_8 + (i * 4), dev_priv->saveFENCE[i+8]);
-		for (i = 0; i < 8; i++)
-			I915_WRITE(FENCE_REG_830_0 + (i * 4), dev_priv->saveFENCE[i]);
-		break;
-	}
-
 	i915_restore_display(dev);
 
 	/* Interrupt state */