diff options
Diffstat (limited to 'Documentation/gpu/drm-mm.rst')
| -rw-r--r-- | Documentation/gpu/drm-mm.rst | 58 |
1 files changed, 29 insertions, 29 deletions
diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst index 59f9822..bca8085 100644 --- a/Documentation/gpu/drm-mm.rst +++ b/Documentation/gpu/drm-mm.rst @@ -26,12 +26,12 @@ TTM, but has no video RAM management capabilities and is thus limited to UMA devices. The Translation Table Manager (TTM) ------------------------------------ +=================================== TTM design background and information belongs here. TTM initialization -~~~~~~~~~~~~~~~~~~ +------------------ **Warning** @@ -77,7 +77,7 @@ object, ttm_global_item_ref() is used to create an initial reference count for the TTM, which will call your initialization function. The Graphics Execution Manager (GEM) ------------------------------------- +==================================== The GEM design approach has resulted in a memory manager that doesn't provide full coverage of all (or even all common) use cases in its @@ -114,7 +114,7 @@ read & write, mapping, and domain ownership transfers are left to driver-specific ioctls. GEM Initialization -~~~~~~~~~~~~~~~~~~ +------------------ Drivers that use GEM must set the DRIVER_GEM bit in the struct :c:type:`struct drm_driver <drm_driver>` driver_features @@ -132,7 +132,7 @@ typically not managed by GEM, and must be initialized separately into its own DRM MM object. GEM Objects Creation -~~~~~~~~~~~~~~~~~~~~ +-------------------- GEM splits creation of GEM objects and allocation of the memory that backs them in two distinct operations. @@ -173,7 +173,7 @@ a call to :c:func:`drm_gem_private_object_init()` instead of must be managed by drivers. GEM Objects Lifetime -~~~~~~~~~~~~~~~~~~~~ +-------------------- All GEM objects are reference-counted by the GEM core. References can be acquired and release by :c:func:`calling @@ -196,7 +196,7 @@ resources created by the GEM core, which need to be released with :c:func:`drm_gem_object_release()`. GEM Objects Naming -~~~~~~~~~~~~~~~~~~ +------------------ Communication between userspace and the kernel refers to GEM objects using local handles, global names or, more recently, file descriptors. @@ -245,7 +245,7 @@ Furthermore PRIME also allows cross-device buffer sharing since it is based on dma-bufs. GEM Objects Mapping -~~~~~~~~~~~~~~~~~~~ +------------------- Because mapping operations are fairly heavyweight GEM favours read/write-like access to buffers, implemented through driver-specific @@ -304,7 +304,7 @@ Drivers that want to map the GEM object upfront instead of handling page faults can implement their own mmap file operation handler. Memory Coherency -~~~~~~~~~~~~~~~~ +---------------- When mapped to the device or used in a command buffer, backing pages for an object are flushed to memory and marked write combined so as to be @@ -320,7 +320,7 @@ blocks the client and waits for rendering to complete before performing any necessary flushing operations). Command Execution -~~~~~~~~~~~~~~~~~ +----------------- Perhaps the most important GEM function for GPU devices is providing a command execution interface to clients. Client programs construct @@ -348,8 +348,20 @@ GEM Function Reference .. kernel-doc:: include/drm/drm_gem.h :internal: +GEM CMA Helper Functions Reference +---------------------------------- + +.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c + :doc: cma helpers + +.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c + :export: + +.. kernel-doc:: include/drm/drm_gem_cma_helper.h + :internal: + VMA Offset Manager ------------------- +================== .. kernel-doc:: drivers/gpu/drm/drm_vma_manager.c :doc: vma offset manager @@ -361,14 +373,14 @@ VMA Offset Manager :internal: PRIME Buffer Sharing --------------------- +==================== PRIME is the cross device buffer sharing framework in drm, originally created for the OPTIMUS range of multi-gpu platforms. To userspace PRIME buffers are dma-buf based file descriptors. Overview and Driver Interface -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +----------------------------- Similar to GEM global names, PRIME file descriptors are also used to share buffer objects across processes. They offer additional security: @@ -406,7 +418,7 @@ struct drm_gem_object \*obj, int flags); struct drm_gem_object \* support PRIME. PRIME Helper Functions -~~~~~~~~~~~~~~~~~~~~~~ +---------------------- .. kernel-doc:: drivers/gpu/drm/drm_prime.c :doc: PRIME Helpers @@ -418,16 +430,16 @@ PRIME Function References :export: DRM MM Range Allocator ----------------------- +====================== Overview -~~~~~~~~ +-------- .. kernel-doc:: drivers/gpu/drm/drm_mm.c :doc: Overview LRU Scan/Eviction Support -~~~~~~~~~~~~~~~~~~~~~~~~~ +------------------------- .. kernel-doc:: drivers/gpu/drm/drm_mm.c :doc: lru scan roaster @@ -440,15 +452,3 @@ DRM MM Range Allocator Function References .. kernel-doc:: include/drm/drm_mm.h :internal: - -CMA Helper Functions Reference ------------------------------- - -.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c - :doc: cma helpers - -.. kernel-doc:: drivers/gpu/drm/drm_gem_cma_helper.c - :export: - -.. kernel-doc:: include/drm/drm_gem_cma_helper.h - :internal: |
