drm/i915: pre-alloc instead of drm_mm search/get_block

i915 is the last user of the weird search+get_block drm_mm API. Convert it
to an explicit kmalloc()+insert_node(). This drops the last user of the
node-cache in drm_mm. We can remove it now in a follow-up patch.

v2:
 - simplify error path in i915_setup_compression()
v3:
 - simplify error path even more

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 47 insertions, 31 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index e3551706f4ff..a3d1a125b5e0 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -112,34 +112,36 @@ 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);
+        int ret;
 
-        /* Try to over-allocate to reduce reallocations and fragmentation */
-        compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
-                                           size <<= 1, 4096,
-                                           DRM_MM_SEARCH_DEFAULT);
-        if (!compressed_fb)
-                compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
-                                                   size >>= 1, 4096,
-                                                   DRM_MM_SEARCH_DEFAULT);
-        if (compressed_fb)
-                compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
+        compressed_fb = kzalloc(sizeof(*compressed_fb), GFP_KERNEL);
         if (!compressed_fb)
-                goto err;
+                goto err_llb;
+
+        /* Try to over-allocate to reduce reallocations and fragmentation */
+        ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_fb,
+                                 size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
+        if (ret)
+                ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_fb,
+                                         size >>= 1, 4096,
+                                         DRM_MM_SEARCH_DEFAULT);
+        if (ret)
+                goto err_llb;
 
         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,
-                                                    DRM_MM_SEARCH_DEFAULT);
-                if (compressed_llb)
-                        compressed_llb = drm_mm_get_block(compressed_llb,
-                                                          4096, 4096);
+                compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
                 if (!compressed_llb)
                         goto err_fb;
 
+                ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
+                                         4096, 4096, DRM_MM_SEARCH_DEFAULT);
+                if (ret)
+                        goto err_fb;
+
                 dev_priv->fbc.compressed_llb = compressed_llb;
 
                 I915_WRITE(FBC_CFB_BASE,
@@ -157,8 +159,10 @@ static int i915_setup_compression(struct drm_device *dev, int size)
         return 0;
 
 err_fb:
-        drm_mm_put_block(compressed_fb);
-err:
+        kfree(compressed_llb);
+        drm_mm_remove_node(compressed_fb);
+err_llb:
+        kfree(compressed_fb);
         pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
         return -ENOSPC;
 }
@@ -186,11 +190,15 @@ void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
         if (dev_priv->fbc.size == 0)
                 return;
 
-        if (dev_priv->fbc.compressed_fb)
-                drm_mm_put_block(dev_priv->fbc.compressed_fb);
+        if (dev_priv->fbc.compressed_fb) {
+                drm_mm_remove_node(dev_priv->fbc.compressed_fb);
+                kfree(dev_priv->fbc.compressed_fb);
+        }
 
-        if (dev_priv->fbc.compressed_llb)
-                drm_mm_put_block(dev_priv->fbc.compressed_llb);
+        if (dev_priv->fbc.compressed_llb) {
+                drm_mm_remove_node(dev_priv->fbc.compressed_llb);
+                kfree(dev_priv->fbc.compressed_llb);
+        }
 
         dev_priv->fbc.size = 0;
 }
@@ -323,6 +331,7 @@ i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
         struct drm_i915_private *dev_priv = dev->dev_private;
         struct drm_i915_gem_object *obj;
         struct drm_mm_node *stolen;
+        int ret;
 
         if (!drm_mm_initialized(&dev_priv->mm.stolen))
                 return NULL;
@@ -331,18 +340,23 @@ i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
         if (size == 0)
                 return NULL;
 
-        stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096,
-                                    DRM_MM_SEARCH_DEFAULT);
-        if (stolen)
-                stolen = drm_mm_get_block(stolen, size, 4096);
-        if (stolen == NULL)
+        stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
+        if (!stolen)
                 return NULL;
 
+        ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
+                                 4096, DRM_MM_SEARCH_DEFAULT);
+        if (ret) {
+                kfree(stolen);
+                return NULL;
+        }
+
         obj = _i915_gem_object_create_stolen(dev, stolen);
         if (obj)
                 return obj;
 
-        drm_mm_put_block(stolen);
+        drm_mm_remove_node(stolen);
+        kfree(stolen);
         return NULL;
 }
 
@@ -386,7 +400,8 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
         obj = _i915_gem_object_create_stolen(dev, stolen);
         if (obj == NULL) {
                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
-                drm_mm_put_block(stolen);
+                drm_mm_remove_node(stolen);
+                kfree(stolen);
                 return NULL;
         }
 
@@ -426,7 +441,8 @@ void
 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 {
         if (obj->stolen) {
-                drm_mm_put_block(obj->stolen);
+                drm_mm_remove_node(obj->stolen);
+                kfree(obj->stolen);
                 obj->stolen = NULL;
         }
 }