[PATCH 06/18] drm/i915: Delay allocation of stolen space for FBC

[Chris Wilson <chris@chris-wilson.co.uk>]

As we may wish to wrap regions preallocated by the BIOS, we need to do
that before carving out contiguous chunks of stolen space for FBC.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_drv.h        |    2 +
 drivers/gpu/drm/i915/i915_gem_stolen.c |  115 ++++++++++++++++----------------
 drivers/gpu/drm/i915/intel_display.c   |    3 +
 drivers/gpu/drm/i915/intel_pm.c        |    3 +-
 4 files changed, 66 insertions(+), 57 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 589b2f3..997abb3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1516,6 +1516,8 @@ int i915_gem_evict_everything(struct drm_device *dev);
 
 /* i915_gem_stolen.c */
 int i915_gem_init_stolen(struct drm_device *dev);
+int i915_gem_stolen_setup_compression(struct drm_device *dev);
+void i915_gem_stolen_cleanup_compression(struct drm_device *dev);
 void i915_gem_cleanup_stolen(struct drm_device *dev);
 
 /* i915_gem_tiling.c */
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index d023ed6..68ef22a 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -89,21 +89,13 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev)
 	return base;
 }
 
-static void i915_warn_stolen(struct drm_device *dev)
-{
-	DRM_INFO("not enough stolen space for compressed buffer, disabling\n");
-	DRM_INFO("hint: you may be able to increase stolen memory size in the BIOS to avoid this\n");
-}
-
-static void i915_setup_compression(struct drm_device *dev, int size)
+static int i915_setup_compression(struct drm_device *dev, int size)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
-	unsigned long cfb_base;
-	unsigned long ll_base = 0;
 
-	/* Just in case the BIOS is doing something questionable. */
-	intel_disable_fbc(dev);
+	DRM_DEBUG_KMS("reserving %d bytes of contiguous stolen space for FBC\n",
+		      size);
 
 	compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
 	if (compressed_fb)
@@ -111,11 +103,11 @@ static void i915_setup_compression(struct drm_device *dev, int size)
 	if (!compressed_fb)
 		goto err;
 
-	cfb_base = dev_priv->mm.stolen_base + compressed_fb->start;
-	if (!cfb_base)
-		goto err_fb;
-
-	if (!(IS_GM45(dev) || HAS_PCH_SPLIT(dev))) {
+	if (HAS_PCH_SPLIT(dev))
+		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
+	else if (IS_GM45(dev)) {
+		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
+	} else {
 		compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
 						    4096, 4096, 0);
 		if (compressed_llb)
@@ -124,56 +116,81 @@ static void i915_setup_compression(struct drm_device *dev, int size)
 		if (!compressed_llb)
 			goto err_fb;
 
-		ll_base = dev_priv->mm.stolen_base + compressed_llb->start;
-		if (!ll_base)
-			goto err_llb;
-	}
+		dev_priv->compressed_llb = compressed_llb;
 
-	dev_priv->cfb_size = size;
+		I915_WRITE(FBC_CFB_BASE,
+			   dev_priv->mm.stolen_base + compressed_fb->start);
+		I915_WRITE(FBC_LL_BASE,
+			   dev_priv->mm.stolen_base + compressed_llb->start);
+	}
 
 	dev_priv->compressed_fb = compressed_fb;
-	if (HAS_PCH_SPLIT(dev))
-		I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
-	else if (IS_GM45(dev)) {
-		I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
-	} else {
-		I915_WRITE(FBC_CFB_BASE, cfb_base);
-		I915_WRITE(FBC_LL_BASE, ll_base);
-		dev_priv->compressed_llb = compressed_llb;
-	}
+	dev_priv->cfb_size = size;
 
-	DRM_DEBUG_KMS("FBC base 0x%08lx, ll base 0x%08lx, size %dM\n",
-		      (long)cfb_base, (long)ll_base, size >> 20);
-	return;
+	return size;
 
-err_llb:
-	drm_mm_put_block(compressed_llb);
 err_fb:
 	drm_mm_put_block(compressed_fb);
 err:
 	dev_priv->no_fbc_reason = FBC_STOLEN_TOO_SMALL;
-	i915_warn_stolen(dev);
+	DRM_INFO("not enough stolen space for compressed buffer (need %d bytes), disabling\n", size);
+	DRM_INFO("hint: you may be able to increase stolen memory size in the BIOS to avoid this\n");
+	return 0;
+}
+
+int i915_gem_stolen_setup_compression(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_mm_node *node;
+	unsigned long hole_start, hole_end, size;
+
+	if (dev_priv->mm.stolen_base == 0)
+		return 0;
+
+	if (dev_priv->cfb_size)
+		return dev_priv->cfb_size;
+
+	/* Try to set up FBC with a reasonable compressed buffer size */
+	size = 0;
+	drm_mm_for_each_hole(node, &dev_priv->mm.stolen, hole_start, hole_end) {
+		unsigned long hole_size = hole_end - hole_start;
+		if (hole_size > size)
+			size = hole_size;
+	}
+
+	/* Try to get a 32M buffer... */
+	if (size > (36*1024*1024))
+		size = 32*1024*1024;
+	else /* fall back to 3/4 of the stolen space */
+		size = size * 3 / 4;
+
+	return i915_setup_compression(dev, size);
 }
 
-static void i915_cleanup_compression(struct drm_device *dev)
+void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	drm_mm_put_block(dev_priv->compressed_fb);
+	if (dev_priv->cfb_size == 0)
+		return;
+
+	if (dev_priv->compressed_fb)
+		drm_mm_put_block(dev_priv->compressed_fb);
+
 	if (dev_priv->compressed_llb)
 		drm_mm_put_block(dev_priv->compressed_llb);
+
+	dev_priv->cfb_size = 0;
 }
 
 void i915_gem_cleanup_stolen(struct drm_device *dev)
 {
-	if (I915_HAS_FBC(dev) && i915_powersave)
-		i915_cleanup_compression(dev);
+	i915_gem_stolen_cleanup_compression(dev);
 }
 
 int i915_gem_init_stolen(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	unsigned long prealloc_size = dev_priv->mm.gtt->stolen_size;
 
 	dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 	if (dev_priv->mm.stolen_base == 0)
@@ -183,21 +200,7 @@ int i915_gem_init_stolen(struct drm_device *dev)
 		      dev_priv->mm.gtt->stolen_size, dev_priv->mm.stolen_base);
 
 	/* Basic memrange allocator for stolen space */
-	drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size);
-
-	/* Try to set up FBC with a reasonable compressed buffer size */
-	if (I915_HAS_FBC(dev) && i915_powersave) {
-		int cfb_size;
-
-		/* Leave 1M for line length buffer & misc. */
-
-		/* Try to get a 32M buffer... */
-		if (prealloc_size > (36*1024*1024))
-			cfb_size = 32*1024*1024;
-		else /* fall back to 7/8 of the stolen space */
-			cfb_size = prealloc_size * 7 / 8;
-		i915_setup_compression(dev, cfb_size);
-	}
+	drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->mm.gtt->stolen_size);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c2c219b..2ef497d0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8351,6 +8351,9 @@ void intel_modeset_init(struct drm_device *dev)
 	/* Just disable it once at startup */
 	i915_disable_vga(dev);
 	intel_setup_outputs(dev);
+
+	/* Just in case the BIOS is doing something questionable. */
+	intel_disable_fbc(dev);
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 2b3cddf..9ee53cb 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -440,7 +440,7 @@ void intel_update_fbc(struct drm_device *dev)
 		dev_priv->no_fbc_reason = FBC_MODULE_PARAM;
 		goto out_disable;
 	}
-	if (intel_fb->obj->base.size > dev_priv->cfb_size) {
+	if (intel_fb->obj->base.size > i915_gem_stolen_setup_compression(dev)) {
 		DRM_DEBUG_KMS("framebuffer too large, disabling "
 			      "compression\n");
 		dev_priv->no_fbc_reason = FBC_STOLEN_TOO_SMALL;
@@ -526,6 +526,7 @@ out_disable:
 		DRM_DEBUG_KMS("unsupported config, disabling FBC\n");
 		intel_disable_fbc(dev);
 	}
+	i915_gem_stolen_cleanup_compression(dev);
 }
 
 static void i915_pineview_get_mem_freq(struct drm_device *dev)
-- 
1.7.10.4