drm/i915: inline vma_create into lookup_or_create_vma

In the execbuf code we don't clean up any vmas which ended up not
getting bound for code simplicity. To make sure that we don't end up
creating multiple vma for the same vm kill the somewhat dangerous
vma_create function and inline it into lookup_or_create.

This is just a safety measure to prevent surprises in the future.

Also update the somewhat confused comment in the execbuf code and
clarify what kind of magic is going on with a new one.

v2: Keep the function separate as requested by Chris. But give it a __
prefix for paranoia and move it tighter together with the other vma
stuff.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Widawsky <ben@bwidawsk.net>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index fc35ae39b9a1a91b869c8241979e17742b16350f..b06a90fdfa558bddb0d4d7af7dc30a1cd285faff 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1748,8 +1748,6 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
 struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
                                                  size_t size);
 void i915_gem_free_object(struct drm_gem_object *obj);
-struct i915_vma *i915_gem_vma_create(struct drm_i915_gem_object *obj,
-                                    struct i915_address_space *vm);
 void i915_gem_vma_destroy(struct i915_vma *vma);
 
 int __must_check i915_gem_object_pin(struct drm_i915_gem_object *obj,

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f0d63cfe8a832929e446f23a4b885130f9840837..d4eda836e8464b43b5a0b9949c0cf8d59d9b60c7 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4120,8 +4120,19 @@ void i915_gem_free_object(struct drm_gem_object *gem_obj)
        i915_gem_object_free(obj);
 }
 
-struct i915_vma *i915_gem_vma_create(struct drm_i915_gem_object *obj,
+struct i915_vma *i915_gem_obj_to_vma(struct drm_i915_gem_object *obj,
                                     struct i915_address_space *vm)
+{
+       struct i915_vma *vma;
+       list_for_each_entry(vma, &obj->vma_list, vma_link)
+               if (vma->vm == vm)
+                       return vma;
+
+       return NULL;
+}
+
+static struct i915_vma *__i915_gem_vma_create(struct drm_i915_gem_object *obj,
+                                             struct i915_address_space *vm)
 {
        struct i915_vma *vma = kzalloc(sizeof(*vma), GFP_KERNEL);
        if (vma == NULL)
@@ -4142,6 +4153,19 @@ struct i915_vma *i915_gem_vma_create(struct drm_i915_gem_object *obj,
        return vma;
 }
 
+struct i915_vma *
+i915_gem_obj_lookup_or_create_vma(struct drm_i915_gem_object *obj,
+                                 struct i915_address_space *vm)
+{
+       struct i915_vma *vma;
+
+       vma = i915_gem_obj_to_vma(obj, vm);
+       if (!vma)
+               vma = __i915_gem_vma_create(obj, vm);
+
+       return vma;
+}
+
 void i915_gem_vma_destroy(struct i915_vma *vma)
 {
        WARN_ON(vma->node.allocated);
@@ -4868,27 +4892,3 @@ unsigned long i915_gem_obj_size(struct drm_i915_gem_object *o,
 
        return 0;
 }
-
-struct i915_vma *i915_gem_obj_to_vma(struct drm_i915_gem_object *obj,
-                                    struct i915_address_space *vm)
-{
-       struct i915_vma *vma;
-       list_for_each_entry(vma, &obj->vma_list, vma_link)
-               if (vma->vm == vm)
-                       return vma;
-
-       return NULL;
-}
-
-struct i915_vma *
-i915_gem_obj_lookup_or_create_vma(struct drm_i915_gem_object *obj,
-                                 struct i915_address_space *vm)
-{
-       struct i915_vma *vma;
-
-       vma = i915_gem_obj_to_vma(obj, vm);
-       if (!vma)
-               vma = i915_gem_vma_create(obj, vm);
-
-       return vma;
-}

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index c3b36f552ef16335ac5165b9c25318423b2383d2..9b3b5f8f954c72c5860b1667afe0ca103a269d3b 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -123,11 +123,16 @@ eb_lookup_vmas(struct eb_vmas *eb,
        list_for_each_entry(obj, &objects, obj_exec_link) {
                struct i915_vma *vma;
 
+               /*
+                * NOTE: We can leak any vmas created here when something fails
+                * later on. But that's no issue since vma_unbind can deal with
+                * vmas which are not actually bound. And since only
+                * lookup_or_create exists as an interface to get at the vma
+                * from the (obj, vm) we don't run the risk of creating
+                * duplicated vmas for the same vm.
+                */
                vma = i915_gem_obj_lookup_or_create_vma(obj, vm);
                if (IS_ERR(vma)) {
-                       /* XXX: We don't need an error path fro vma because if
-                        * the vma was created just for this execbuf, object
-                        * unreference should kill it off.*/
                        DRM_DEBUG("Failed to lookup VMA\n");
                        ret = PTR_ERR(vma);
                        goto out;

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index 7f4c510a751b3825d3c768f71414956e77d92b2b..b2391852359d42ddea5cc5d9d103992a22eaffec 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -375,7 +375,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
        if (gtt_offset == I915_GTT_OFFSET_NONE)
                return obj;
 
-       vma = i915_gem_vma_create(obj, ggtt);
+       vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
        if (IS_ERR(vma)) {
                ret = PTR_ERR(vma);
                goto err_out;