drm: pre allocate node for create_block

For an upcoming patch where we introduce the i915 VMA, it's ideal to
have the drm_mm_node as part of the VMA struct (ie. it's pre-allocated).
Part of the conversion to VMAs is to kill off obj->gtt_space. Doing this
will break a bunch of code, but amongst them are 2 callers of
drm_mm_create_block(), both related to stolen memory.

It also allows us to embed the drm_mm_node into the object currently
which provides a nice transition over to the new code.

v2: Reordered to do before ripping out obj->gtt_offset.
Some minor cleanups made available because of reordering.

v3: s/continue/break on failed stolen node allocation (David)
Set obj->gtt_space on failed node allocation (David)
Only unref stolen (fix double free) on failed create_stolen (David)
Free node, and NULL it in failed create_stolen (David)
Add back accidentally removed newline (David)

CC: <dri-devel@lists.freedesktop.org>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 07cf99c..9e8dfbc 100644 (file)
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -147,12 +147,10 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
        }
 }
 
-struct drm_mm_node *drm_mm_create_block(struct drm_mm *mm,
-                                       unsigned long start,
-                                       unsigned long size,
-                                       bool atomic)
+int drm_mm_create_block(struct drm_mm *mm, struct drm_mm_node *node,
+                       unsigned long start, unsigned long size)
 {
-       struct drm_mm_node *hole, *node;
+       struct drm_mm_node *hole;
        unsigned long end = start + size;
        unsigned long hole_start;
        unsigned long hole_end;
@@ -161,10 +159,6 @@ struct drm_mm_node *drm_mm_create_block(struct drm_mm *mm,
                if (hole_start > start || hole_end < end)
                        continue;
 
-               node = drm_mm_kmalloc(mm, atomic);
-               if (unlikely(node == NULL))
-                       return NULL;
-
                node->start = start;
                node->size = size;
                node->mm = mm;
@@ -184,11 +178,11 @@ struct drm_mm_node *drm_mm_create_block(struct drm_mm *mm,
                        node->hole_follows = 1;
                }
 
-               return node;
+               return 0;
        }
 
        WARN(1, "no hole found for block 0x%lx + 0x%lx\n", start, size);
-       return NULL;
+       return -ENOSPC;
 }
 EXPORT_SYMBOL(drm_mm_create_block);
 

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 66929ea..88180a5 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -629,14 +629,26 @@ void i915_gem_setup_global_gtt(struct drm_device *dev,
 
        /* Mark any preallocated objects as occupied */
        list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
+               int ret;
                DRM_DEBUG_KMS("reserving preallocated space: %x + %zx\n",
                              obj->gtt_offset, obj->base.size);
 
                BUG_ON(obj->gtt_space != I915_GTT_RESERVED);
-               obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
-                                                    obj->gtt_offset,
-                                                    obj->base.size,
-                                                    false);
+               obj->gtt_space = kzalloc(sizeof(*obj->gtt_space), GFP_KERNEL);
+               if (!obj->gtt_space) {
+                       DRM_ERROR("Failed to preserve object at offset %x\n",
+                                 obj->gtt_offset);
+                       continue;
+               }
+               ret = drm_mm_create_block(&dev_priv->mm.gtt_space,
+                                         obj->gtt_space,
+                                         obj->gtt_offset,
+                                         obj->base.size);
+               if (ret) {
+                       DRM_DEBUG_KMS("Reservation failed\n");
+                       kfree(obj->gtt_space);
+                       obj->gtt_space = NULL;
+               }
                obj->has_global_gtt_mapping = 1;
        }
 

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 0f18d75..2746ff2 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -330,6 +330,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_i915_gem_object *obj;
        struct drm_mm_node *stolen;
+       int ret;
 
        if (dev_priv->mm.stolen_base == 0)
                return NULL;
@@ -344,11 +345,15 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
        if (WARN_ON(size == 0))
                return NULL;
 
-       stolen = drm_mm_create_block(&dev_priv->mm.stolen,
-                                    stolen_offset, size,
-                                    false);
-       if (stolen == NULL) {
+       stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
+       if (!stolen)
+               return NULL;
+
+       ret = drm_mm_create_block(&dev_priv->mm.stolen, stolen, stolen_offset,
+                                 size);
+       if (ret) {
                DRM_DEBUG_KMS("failed to allocate stolen space\n");
+               kfree(stolen);
                return NULL;
        }
 
@@ -369,13 +374,18 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
         * later.
         */
        if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
-               obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
-                                                    gtt_offset, size,
-                                                    false);
-               if (obj->gtt_space == NULL) {
+               obj->gtt_space = kzalloc(sizeof(*obj->gtt_space), GFP_KERNEL);
+               if (!obj->gtt_space) {
+                       DRM_DEBUG_KMS("-ENOMEM stolen GTT space\n");
+                       goto unref_out;
+               }
+
+               ret = drm_mm_create_block(&dev_priv->mm.gtt_space,
+                                         obj->gtt_space,
+                                         gtt_offset, size);
+               if (ret) {
                        DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
-                       drm_gem_object_unreference(&obj->base);
-                       return NULL;
+                       goto free_out;
                }
        } else
                obj->gtt_space = I915_GTT_RESERVED;
@@ -387,6 +397,13 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
        list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
        return obj;
+
+free_out:
+       kfree(obj->gtt_space);
+       obj->gtt_space = NULL;
+unref_out:
+       drm_gem_object_unreference(&obj->base);
+       return NULL;
 }
 
 void

diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index 88591ef..d8b56b7 100644 (file)
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -138,10 +138,10 @@ static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
 /*
  * Basic range manager support (drm_mm.c)
  */
-extern struct drm_mm_node *drm_mm_create_block(struct drm_mm *mm,
-                                              unsigned long start,
-                                              unsigned long size,
-                                              bool atomic);
+extern int drm_mm_create_block(struct drm_mm *mm,
+                              struct drm_mm_node *node,
+                              unsigned long start,
+                              unsigned long size);
 extern struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
                                                    unsigned long size,
                                                    unsigned alignment,
@@ -155,6 +155,7 @@ extern struct drm_mm_node *drm_mm_get_block_range_generic(
                                                unsigned long start,
                                                unsigned long end,
                                                int atomic);
+
 static inline struct drm_mm_node *drm_mm_get_block(struct drm_mm_node *parent,
                                                   unsigned long size,
                                                   unsigned alignment)