drm/i915: Create VMAs

Formerly: "drm/i915: Create VMAs (part 1)"

In a previous patch, the notion of a VM was introduced. A VMA describes
an area of part of the VM address space. A VMA is similar to the concept
in the linux mm. However, instead of representing regular memory, a VMA
is backed by a GEM BO. There may be many VMAs for a given object, one
for each VM the object is to be used in. This may occur through flink,
dma-buf, or a number of other transient states.

Currently the code depends on only 1 VMA per object, for the global GTT
(and aliasing PPGTT). The following patches will address this and make
the rest of the infrastructure more suited

v2: s/i915_obj/i915_gem_obj (Chris)

v3: Only move an object to the now global unbound list if there are no
more VMAs for the object which are bound into a VM (ie. the list is
empty).

v4: killed obj->gtt_space
some reworks due to rebase

v5: Free vma on error path (Imre)

v6: Another missed vma free in i915_gem_object_bind_to_gtt error path
(Imre)
Fixed vma freeing in stolen preallocation (Imre)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Imre Deak <imre.deak@intel.com>
[danvet: Squash in fixup from Ben to not deref a non-existing vma in
set_cache_level, reported by Chris.]
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 ee21af3..bd1b95e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -533,6 +533,17 @@ struct i915_hw_ppgtt {
        int (*enable)(struct drm_device *dev);
 };
 
+/* To make things as simple as possible (ie. no refcounting), a VMA's lifetime
+ * will always be <= an objects lifetime. So object refcounting should cover us.
+ */
+struct i915_vma {
+       struct drm_mm_node node;
+       struct drm_i915_gem_object *obj;
+       struct i915_address_space *vm;
+
+       struct list_head vma_link; /* Link in the object's VMA list */
+};
+
 struct i915_ctx_hang_stats {
        /* This context had batch pending when hang was declared */
        unsigned batch_pending;
@@ -1229,8 +1240,9 @@ struct drm_i915_gem_object {
 
        const struct drm_i915_gem_object_ops *ops;
 
-       /** Current space allocated to this object in the GTT, if any. */
-       struct drm_mm_node gtt_space;
+       /** List of VMAs backed by this object */
+       struct list_head vma_list;
+
        /** Stolen memory for this object, instead of being backed by shmem. */
        struct drm_mm_node *stolen;
        struct list_head global_list;
@@ -1356,18 +1368,32 @@ struct drm_i915_gem_object {
 
 #define to_intel_bo(x) container_of(x, struct drm_i915_gem_object, base)
 
-/* Offset of the first PTE pointing to this object */
-static inline unsigned long
-i915_gem_obj_ggtt_offset(struct drm_i915_gem_object *o)
+/* This is a temporary define to help transition us to real VMAs. If you see
+ * this, you're either reviewing code, or bisecting it. */
+static inline struct i915_vma *
+__i915_gem_obj_to_vma(struct drm_i915_gem_object *obj)
 {
-       return o->gtt_space.start;
+       if (list_empty(&obj->vma_list))
+               return NULL;
+       return list_first_entry(&obj->vma_list, struct i915_vma, vma_link);
 }
 
 /* Whether or not this object is currently mapped by the translation tables */
 static inline bool
 i915_gem_obj_ggtt_bound(struct drm_i915_gem_object *o)
 {
-       return drm_mm_node_allocated(&o->gtt_space);
+       struct i915_vma *vma = __i915_gem_obj_to_vma(o);
+       if (vma == NULL)
+               return false;
+       return drm_mm_node_allocated(&vma->node);
+}
+
+/* Offset of the first PTE pointing to this object */
+static inline unsigned long
+i915_gem_obj_ggtt_offset(struct drm_i915_gem_object *o)
+{
+       BUG_ON(list_empty(&o->vma_list));
+       return __i915_gem_obj_to_vma(o)->node.start;
 }
 
 /* The size used in the translation tables may be larger than the actual size of
@@ -1377,14 +1403,15 @@ i915_gem_obj_ggtt_bound(struct drm_i915_gem_object *o)
 static inline unsigned long
 i915_gem_obj_ggtt_size(struct drm_i915_gem_object *o)
 {
-       return o->gtt_space.size;
+       BUG_ON(list_empty(&o->vma_list));
+       return __i915_gem_obj_to_vma(o)->node.size;
 }
 
 static inline void
 i915_gem_obj_ggtt_set_color(struct drm_i915_gem_object *o,
                            enum i915_cache_level color)
 {
-       o->gtt_space.color = color;
+       __i915_gem_obj_to_vma(o)->node.color = color;
 }
 
 /**
@@ -1691,6 +1718,9 @@ 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,
                                     uint32_t alignment,

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8830856..bd8c008 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2587,6 +2587,7 @@ int
 i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 {
        drm_i915_private_t *dev_priv = obj->base.dev->dev_private;
+       struct i915_vma *vma;
        int ret;
 
        if (!i915_gem_obj_ggtt_bound(obj))
@@ -2624,11 +2625,20 @@ i915_gem_object_unbind(struct drm_i915_gem_object *obj)
        i915_gem_object_unpin_pages(obj);
 
        list_del(&obj->mm_list);
-       list_move_tail(&obj->global_list, &dev_priv->mm.unbound_list);
        /* Avoid an unnecessary call to unbind on rebind. */
        obj->map_and_fenceable = true;
 
-       drm_mm_remove_node(&obj->gtt_space);
+       vma = __i915_gem_obj_to_vma(obj);
+       list_del(&vma->vma_link);
+       drm_mm_remove_node(&vma->node);
+       i915_gem_vma_destroy(vma);
+
+       /* Since the unbound list is global, only move to that list if
+        * no more VMAs exist.
+        * NB: Until we have real VMAs there will only ever be one */
+       WARN_ON(!list_empty(&obj->vma_list));
+       if (list_empty(&obj->vma_list))
+               list_move_tail(&obj->global_list, &dev_priv->mm.unbound_list);
 
        return 0;
 }
@@ -3079,8 +3089,12 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
        bool mappable, fenceable;
        size_t gtt_max = map_and_fenceable ?
                dev_priv->gtt.mappable_end : dev_priv->gtt.base.total;
+       struct i915_vma *vma;
        int ret;
 
+       if (WARN_ON(!list_empty(&obj->vma_list)))
+               return -EBUSY;
+
        fence_size = i915_gem_get_gtt_size(dev,
                                           obj->base.size,
                                           obj->tiling_mode);
@@ -3119,9 +3133,15 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 
        i915_gem_object_pin_pages(obj);
 
+       vma = i915_gem_vma_create(obj, &dev_priv->gtt.base);
+       if (vma == NULL) {
+               i915_gem_object_unpin_pages(obj);
+               return -ENOMEM;
+       }
+
 search_free:
        ret = drm_mm_insert_node_in_range_generic(&dev_priv->gtt.base.mm,
-                                                 &obj->gtt_space,
+                                                 &vma->node,
                                                  size, alignment,
                                                  obj->cache_level, 0, gtt_max);
        if (ret) {
@@ -3132,25 +3152,21 @@ search_free:
                if (ret == 0)
                        goto search_free;
 
-               i915_gem_object_unpin_pages(obj);
-               return ret;
+               goto err_out;
        }
-       if (WARN_ON(!i915_gem_valid_gtt_space(dev, &obj->gtt_space,
+       if (WARN_ON(!i915_gem_valid_gtt_space(dev, &vma->node,
                                              obj->cache_level))) {
-               i915_gem_object_unpin_pages(obj);
-               drm_mm_remove_node(&obj->gtt_space);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto err_out;
        }
 
        ret = i915_gem_gtt_prepare_object(obj);
-       if (ret) {
-               i915_gem_object_unpin_pages(obj);
-               drm_mm_remove_node(&obj->gtt_space);
-               return ret;
-       }
+       if (ret)
+               goto err_out;
 
        list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
        list_add_tail(&obj->mm_list, &vm->inactive_list);
+       list_add(&vma->vma_link, &obj->vma_list);
 
        fenceable =
                i915_gem_obj_ggtt_size(obj) == fence_size &&
@@ -3164,6 +3180,12 @@ search_free:
        trace_i915_gem_object_bind(obj, map_and_fenceable);
        i915_gem_verify_gtt(dev);
        return 0;
+
+err_out:
+       i915_gem_vma_destroy(vma);
+       i915_gem_object_unpin_pages(obj);
+       drm_mm_remove_node(&vma->node);
+       return ret;
 }
 
 void
@@ -3309,6 +3331,7 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
 {
        struct drm_device *dev = obj->base.dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
+       struct i915_vma *vma = __i915_gem_obj_to_vma(obj);
        int ret;
 
        if (obj->cache_level == cache_level)
@@ -3319,7 +3342,7 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
                return -EBUSY;
        }
 
-       if (!i915_gem_valid_gtt_space(dev, &obj->gtt_space, cache_level)) {
+       if (vma && !i915_gem_valid_gtt_space(dev, &vma->node, cache_level)) {
                ret = i915_gem_object_unbind(obj);
                if (ret)
                        return ret;
@@ -3864,6 +3887,7 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
        INIT_LIST_HEAD(&obj->global_list);
        INIT_LIST_HEAD(&obj->ring_list);
        INIT_LIST_HEAD(&obj->exec_list);
+       INIT_LIST_HEAD(&obj->vma_list);
 
        obj->ops = ops;
 
@@ -3984,6 +4008,26 @@ 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_address_space *vm)
+{
+       struct i915_vma *vma = kzalloc(sizeof(*vma), GFP_KERNEL);
+       if (vma == NULL)
+               return ERR_PTR(-ENOMEM);
+
+       INIT_LIST_HEAD(&vma->vma_link);
+       vma->vm = vm;
+       vma->obj = obj;
+
+       return vma;
+}
+
+void i915_gem_vma_destroy(struct i915_vma *vma)
+{
+       WARN_ON(vma->node.allocated);
+       kfree(vma);
+}
+
 int
 i915_gem_idle(struct drm_device *dev)
 {

diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index 43b8235..df61f33 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -34,11 +34,13 @@
 static bool
 mark_free(struct drm_i915_gem_object *obj, struct list_head *unwind)
 {
+       struct i915_vma *vma = __i915_gem_obj_to_vma(obj);
+
        if (obj->pin_count)
                return false;
 
        list_add(&obj->exec_list, unwind);
-       return drm_mm_scan_add_block(&obj->gtt_space);
+       return drm_mm_scan_add_block(&vma->node);
 }
 
 int
@@ -49,6 +51,7 @@ i915_gem_evict_something(struct drm_device *dev, int min_size,
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct i915_address_space *vm = &dev_priv->gtt.base;
        struct list_head eviction_list, unwind_list;
+       struct i915_vma *vma;
        struct drm_i915_gem_object *obj;
        int ret = 0;
 
@@ -106,8 +109,8 @@ none:
                obj = list_first_entry(&unwind_list,
                                       struct drm_i915_gem_object,
                                       exec_list);
-
-               ret = drm_mm_scan_remove_block(&obj->gtt_space);
+               vma = __i915_gem_obj_to_vma(obj);
+               ret = drm_mm_scan_remove_block(&vma->node);
                BUG_ON(ret);
 
                list_del_init(&obj->exec_list);
@@ -127,7 +130,8 @@ found:
                obj = list_first_entry(&unwind_list,
                                       struct drm_i915_gem_object,
                                       exec_list);
-               if (drm_mm_scan_remove_block(&obj->gtt_space)) {
+               vma = __i915_gem_obj_to_vma(obj);
+               if (drm_mm_scan_remove_block(&vma->node)) {
                        list_move(&obj->exec_list, &eviction_list);
                        drm_gem_object_reference(&obj->base);
                        continue;

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 999ecfe..3b639a9 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -662,16 +662,17 @@ 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) {
+               struct i915_vma *vma = __i915_gem_obj_to_vma(obj);
                int ret;
                DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
                              i915_gem_obj_ggtt_offset(obj), obj->base.size);
 
                WARN_ON(i915_gem_obj_ggtt_bound(obj));
-               ret = drm_mm_reserve_node(&dev_priv->gtt.base.mm,
-                                         &obj->gtt_space);
+               ret = drm_mm_reserve_node(&dev_priv->gtt.base.mm, &vma->node);
                if (ret)
                        DRM_DEBUG_KMS("Reservation failed\n");
                obj->has_global_gtt_mapping = 1;
+               list_add(&vma->vma_link, &obj->vma_list);
        }
 
        dev_priv->gtt.base.start = start;

diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index cb527e7..fc894f7 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -351,6 +351,7 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
        struct i915_address_space *vm = &dev_priv->gtt.base;
        struct drm_i915_gem_object *obj;
        struct drm_mm_node *stolen;
+       struct i915_vma *vma;
        int ret;
 
        if (dev_priv->mm.stolen_base == 0)
@@ -390,18 +391,24 @@ 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, &dev_priv->gtt.base);
+       if (!vma) {
+               ret = -ENOMEM;
+               goto err_out;
+       }
+
        /* To simplify the initialisation sequence between KMS and GTT,
         * we allow construction of the stolen object prior to
         * setting up the GTT space. The actual reservation will occur
         * later.
         */
-       obj->gtt_space.start = gtt_offset;
-       obj->gtt_space.size = size;
+       vma->node.start = gtt_offset;
+       vma->node.size = size;
        if (drm_mm_initialized(&dev_priv->gtt.base.mm)) {
-               ret = drm_mm_reserve_node(&dev_priv->gtt.base.mm,
-                                         &obj->gtt_space);
+               ret = drm_mm_reserve_node(&dev_priv->gtt.base.mm, &vma->node);
                if (ret) {
                        DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
+                       i915_gem_vma_destroy(vma);
                        goto err_out;
                }
        }