drm/gpuvm: add an abstraction for a VM / BO combination

Add an abstraction layer between the drm_gpuva mappings of a particular
drm_gem_object and this GEM object itself. The abstraction represents a
combination of a drm_gem_object and drm_gpuvm. The drm_gem_object holds
a list of drm_gpuvm_bo structures (the structure representing this
abstraction), while each drm_gpuvm_bo contains list of mappings of this
GEM object.

This has multiple advantages:

1) We can use the drm_gpuvm_bo structure to attach it to various lists
   of the drm_gpuvm. This is useful for tracking external and evicted
   objects per VM, which is introduced in subsequent patches.

2) Finding mappings of a certain drm_gem_object mapped in a certain
   drm_gpuvm becomes much cheaper.

3) Drivers can derive and extend the structure to easily represent
   driver specific states of a BO for a certain GPUVM.

The idea of this abstraction was taken from amdgpu, hence the credit for
this idea goes to the developers of amdgpu.

Cc: Christian König <christian.koenig@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Danilo Krummrich <dakr@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231108001259.15123-11-dakr@redhat.com

1 files changed, 16 insertions, 16 deletions

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 16364487fde9..369505447acd 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -580,7 +580,7 @@ int drm_gem_evict(struct drm_gem_object *obj);
  * drm_gem_gpuva_init() - initialize the gpuva list of a GEM object
  * @obj: the &drm_gem_object
  *
- * This initializes the &drm_gem_object's &drm_gpuva list.
+ * This initializes the &drm_gem_object's &drm_gpuvm_bo list.
  *
  * Calling this function is only necessary for drivers intending to support the
  * &drm_driver_feature DRIVER_GEM_GPUVA.
@@ -593,28 +593,28 @@ static inline void drm_gem_gpuva_init(struct drm_gem_object *obj)
 }
 
 /**
- * drm_gem_for_each_gpuva() - iternator to walk over a list of gpuvas
- * @entry__: &drm_gpuva structure to assign to in each iteration step
- * @obj__: the &drm_gem_object the &drm_gpuvas to walk are associated with
+ * drm_gem_for_each_gpuvm_bo() - iterator to walk over a list of &drm_gpuvm_bo
+ * @entry__: &drm_gpuvm_bo structure to assign to in each iteration step
+ * @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are associated with
  *
- * This iterator walks over all &drm_gpuva structures associated with the
- * &drm_gpuva_manager.
+ * This iterator walks over all &drm_gpuvm_bo structures associated with the
+ * &drm_gem_object.
  */
-#define drm_gem_for_each_gpuva(entry__, obj__) \
-	list_for_each_entry(entry__, &(obj__)->gpuva.list, gem.entry)
+#define drm_gem_for_each_gpuvm_bo(entry__, obj__) \
+	list_for_each_entry(entry__, &(obj__)->gpuva.list, list.entry.gem)
 
 /**
- * drm_gem_for_each_gpuva_safe() - iternator to safely walk over a list of
- * gpuvas
- * @entry__: &drm_gpuva structure to assign to in each iteration step
- * @next__: &next &drm_gpuva to store the next step
- * @obj__: the &drm_gem_object the &drm_gpuvas to walk are associated with
+ * drm_gem_for_each_gpuvm_bo_safe() - iterator to safely walk over a list of
+ * &drm_gpuvm_bo
+ * @entry__: &drm_gpuvm_bostructure to assign to in each iteration step
+ * @next__: &next &drm_gpuvm_bo to store the next step
+ * @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are associated with
  *
- * This iterator walks over all &drm_gpuva structures associated with the
+ * This iterator walks over all &drm_gpuvm_bo structures associated with the
  * &drm_gem_object. It is implemented with list_for_each_entry_safe(), hence
  * it is save against removal of elements.
  */
-#define drm_gem_for_each_gpuva_safe(entry__, next__, obj__) \
-	list_for_each_entry_safe(entry__, next__, &(obj__)->gpuva.list, gem.entry)
+#define drm_gem_for_each_gpuvm_bo_safe(entry__, next__, obj__) \
+	list_for_each_entry_safe(entry__, next__, &(obj__)->gpuva.list, list.entry.gem)
 
 #endif /* __DRM_GEM_H__ */