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Diffstat (limited to 'Documentation/gpu/drm-mm.rst')
| -rw-r--r-- | Documentation/gpu/drm-mm.rst | 40 |
1 files changed, 29 insertions, 11 deletions
diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst index cb5daffcd6be..1ea94fc86caa 100644 --- a/Documentation/gpu/drm-mm.rst +++ b/Documentation/gpu/drm-mm.rst @@ -34,25 +34,26 @@ TTM initialization ------------------ **Warning** - This section is outdated. -Drivers wishing to support TTM must fill out a drm_bo_driver -structure. The structure contains several fields with function pointers -for initializing the TTM, allocating and freeing memory, waiting for -command completion and fence synchronization, and memory migration. See -the radeon_ttm.c file for an example of usage. +Drivers wishing to support TTM must pass a filled :c:type:`ttm_bo_driver +<ttm_bo_driver>` structure to ttm_bo_device_init, together with an +initialized global reference to the memory manager. The ttm_bo_driver +structure contains several fields with function pointers for +initializing the TTM, allocating and freeing memory, waiting for command +completion and fence synchronization, and memory migration. -The ttm_global_reference structure is made up of several fields: +The :c:type:`struct drm_global_reference <drm_global_reference>` is made +up of several fields: .. code-block:: c - struct ttm_global_reference { + struct drm_global_reference { enum ttm_global_types global_type; size_t size; void *object; - int (*init) (struct ttm_global_reference *); - void (*release) (struct ttm_global_reference *); + int (*init) (struct drm_global_reference *); + void (*release) (struct drm_global_reference *); }; @@ -76,6 +77,12 @@ ttm_bo_global_release(), respectively. Also, like the previous object, ttm_global_item_ref() is used to create an initial reference count for the TTM, which will call your initialization function. +See the radeon_ttm.c file for an example of usage. + +.. kernel-doc:: drivers/gpu/drm/drm_global.c + :export: + + The Graphics Execution Manager (GEM) ==================================== @@ -303,6 +310,17 @@ created. Drivers that want to map the GEM object upfront instead of handling page faults can implement their own mmap file operation handler. +For platforms without MMU the GEM core provides a helper method +:c:func:`drm_gem_cma_get_unmapped_area`. The mmap() routines will call +this to get a proposed address for the mapping. + +To use :c:func:`drm_gem_cma_get_unmapped_area`, drivers must fill the +struct :c:type:`struct file_operations <file_operations>` get_unmapped_area +field with a pointer on :c:func:`drm_gem_cma_get_unmapped_area`. + +More detailed information about get_unmapped_area can be found in +Documentation/nommu-mmap.txt + Memory Coherency ---------------- @@ -442,7 +460,7 @@ LRU Scan/Eviction Support ------------------------- .. kernel-doc:: drivers/gpu/drm/drm_mm.c - :doc: lru scan roaster + :doc: lru scan roster DRM MM Range Allocator Function References ------------------------------------------ |