diff options
Diffstat (limited to 'Documentation/DocBook/drm.tmpl')
| -rw-r--r-- | Documentation/DocBook/drm.tmpl | 274 |
1 files changed, 140 insertions, 134 deletions
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index b8bfa8d1f289..8c54f9a393cf 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -492,10 +492,10 @@ char *date;</synopsis> <sect2> <title>The Translation Table Manager (TTM)</title> <para> - TTM design background and information belongs here. + TTM design background and information belongs here. </para> <sect3> - <title>TTM initialization</title> + <title>TTM initialization</title> <warning><para>This section is outdated.</para></warning> <para> Drivers wishing to support TTM must fill out a drm_bo_driver @@ -503,42 +503,42 @@ char *date;</synopsis> 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. - </para> - <para> - The ttm_global_reference structure is made up of several fields: - </para> - <programlisting> - struct ttm_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 *); - }; - </programlisting> - <para> - There should be one global reference structure for your memory - manager as a whole, and there will be others for each object - created by the memory manager at runtime. Your global TTM should - have a type of TTM_GLOBAL_TTM_MEM. The size field for the global - object should be sizeof(struct ttm_mem_global), and the init and - release hooks should point at your driver-specific init and - release routines, which probably eventually call - ttm_mem_global_init and ttm_mem_global_release, respectively. - </para> - <para> - Once your global TTM accounting structure is set up and initialized - by calling ttm_global_item_ref() on it, - you need to create a buffer object TTM to - provide a pool for buffer object allocation by clients and the - kernel itself. The type of this object should be TTM_GLOBAL_TTM_BO, - and its size should be sizeof(struct ttm_bo_global). Again, - driver-specific init and release functions may be provided, - likely eventually calling ttm_bo_global_init() and - 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. - </para> + </para> + <para> + The ttm_global_reference structure is made up of several fields: + </para> + <programlisting> + struct ttm_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 *); + }; + </programlisting> + <para> + There should be one global reference structure for your memory + manager as a whole, and there will be others for each object + created by the memory manager at runtime. Your global TTM should + have a type of TTM_GLOBAL_TTM_MEM. The size field for the global + object should be sizeof(struct ttm_mem_global), and the init and + release hooks should point at your driver-specific init and + release routines, which probably eventually call + ttm_mem_global_init and ttm_mem_global_release, respectively. + </para> + <para> + Once your global TTM accounting structure is set up and initialized + by calling ttm_global_item_ref() on it, + you need to create a buffer object TTM to + provide a pool for buffer object allocation by clients and the + kernel itself. The type of this object should be TTM_GLOBAL_TTM_BO, + and its size should be sizeof(struct ttm_bo_global). Again, + driver-specific init and release functions may be provided, + likely eventually calling ttm_bo_global_init() and + 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. + </para> </sect3> </sect2> <sect2 id="drm-gem"> @@ -566,19 +566,19 @@ char *date;</synopsis> using driver-specific ioctls. </para> <para> - On a fundamental level, GEM involves several operations: - <itemizedlist> - <listitem>Memory allocation and freeing</listitem> - <listitem>Command execution</listitem> - <listitem>Aperture management at command execution time</listitem> - </itemizedlist> - Buffer object allocation is relatively straightforward and largely + On a fundamental level, GEM involves several operations: + <itemizedlist> + <listitem>Memory allocation and freeing</listitem> + <listitem>Command execution</listitem> + <listitem>Aperture management at command execution time</listitem> + </itemizedlist> + Buffer object allocation is relatively straightforward and largely provided by Linux's shmem layer, which provides memory to back each object. </para> <para> Device-specific operations, such as command execution, pinning, buffer - read & write, mapping, and domain ownership transfers are left to + read & write, mapping, and domain ownership transfers are left to driver-specific ioctls. </para> <sect3> @@ -738,16 +738,16 @@ char *date;</synopsis> respectively. The conversion is handled by the DRM core without any driver-specific support. </para> - <para> - GEM also supports buffer sharing with dma-buf file descriptors through - PRIME. GEM-based drivers must use the provided helpers functions to - implement the exporting and importing correctly. See <xref linkend="drm-prime-support" />. - Since sharing file descriptors is inherently more secure than the - easily guessable and global GEM names it is the preferred buffer - sharing mechanism. Sharing buffers through GEM names is only supported - for legacy userspace. Furthermore PRIME also allows cross-device - buffer sharing since it is based on dma-bufs. - </para> + <para> + GEM also supports buffer sharing with dma-buf file descriptors through + PRIME. GEM-based drivers must use the provided helpers functions to + implement the exporting and importing correctly. See <xref linkend="drm-prime-support" />. + Since sharing file descriptors is inherently more secure than the + easily guessable and global GEM names it is the preferred buffer + sharing mechanism. Sharing buffers through GEM names is only supported + for legacy userspace. Furthermore PRIME also allows cross-device + buffer sharing since it is based on dma-bufs. + </para> </sect3> <sect3 id="drm-gem-objects-mapping"> <title>GEM Objects Mapping</title> @@ -852,7 +852,7 @@ char *date;</synopsis> <sect3> <title>Command Execution</title> <para> - Perhaps the most important GEM function for GPU devices is providing a + Perhaps the most important GEM function for GPU devices is providing a command execution interface to clients. Client programs construct command buffers containing references to previously allocated memory objects, and then submit them to GEM. At that point, GEM takes care to @@ -874,95 +874,101 @@ char *date;</synopsis> <title>GEM Function Reference</title> !Edrivers/gpu/drm/drm_gem.c </sect3> - </sect2> - <sect2> - <title>VMA Offset Manager</title> + </sect2> + <sect2> + <title>VMA Offset Manager</title> !Pdrivers/gpu/drm/drm_vma_manager.c vma offset manager !Edrivers/gpu/drm/drm_vma_manager.c !Iinclude/drm/drm_vma_manager.h - </sect2> - <sect2 id="drm-prime-support"> - <title>PRIME Buffer Sharing</title> - <para> - 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. - </para> - <sect3> - <title>Overview and Driver Interface</title> - <para> - Similar to GEM global names, PRIME file descriptors are - also used to share buffer objects across processes. They offer - additional security: as file descriptors must be explicitly sent over - UNIX domain sockets to be shared between applications, they can't be - guessed like the globally unique GEM names. - </para> - <para> - Drivers that support the PRIME - API must set the DRIVER_PRIME bit in the struct - <structname>drm_driver</structname> - <structfield>driver_features</structfield> field, and implement the - <methodname>prime_handle_to_fd</methodname> and - <methodname>prime_fd_to_handle</methodname> operations. - </para> - <para> - <synopsis>int (*prime_handle_to_fd)(struct drm_device *dev, - struct drm_file *file_priv, uint32_t handle, - uint32_t flags, int *prime_fd); + </sect2> + <sect2 id="drm-prime-support"> + <title>PRIME Buffer Sharing</title> + <para> + 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. + </para> + <sect3> + <title>Overview and Driver Interface</title> + <para> + Similar to GEM global names, PRIME file descriptors are + also used to share buffer objects across processes. They offer + additional security: as file descriptors must be explicitly sent over + UNIX domain sockets to be shared between applications, they can't be + guessed like the globally unique GEM names. + </para> + <para> + Drivers that support the PRIME + API must set the DRIVER_PRIME bit in the struct + <structname>drm_driver</structname> + <structfield>driver_features</structfield> field, and implement the + <methodname>prime_handle_to_fd</methodname> and + <methodname>prime_fd_to_handle</methodname> operations. + </para> + <para> + <synopsis>int (*prime_handle_to_fd)(struct drm_device *dev, + struct drm_file *file_priv, uint32_t handle, + uint32_t flags, int *prime_fd); int (*prime_fd_to_handle)(struct drm_device *dev, - struct drm_file *file_priv, int prime_fd, - uint32_t *handle);</synopsis> - Those two operations convert a handle to a PRIME file descriptor and - vice versa. Drivers must use the kernel dma-buf buffer sharing framework - to manage the PRIME file descriptors. Similar to the mode setting - API PRIME is agnostic to the underlying buffer object manager, as - long as handles are 32bit unsigned integers. - </para> - <para> - While non-GEM drivers must implement the operations themselves, GEM - drivers must use the <function>drm_gem_prime_handle_to_fd</function> - and <function>drm_gem_prime_fd_to_handle</function> helper functions. - Those helpers rely on the driver - <methodname>gem_prime_export</methodname> and - <methodname>gem_prime_import</methodname> operations to create a dma-buf - instance from a GEM object (dma-buf exporter role) and to create a GEM - object from a dma-buf instance (dma-buf importer role). - </para> - <para> - <synopsis>struct dma_buf * (*gem_prime_export)(struct drm_device *dev, - struct drm_gem_object *obj, - int flags); + struct drm_file *file_priv, int prime_fd, + uint32_t *handle);</synopsis> + Those two operations convert a handle to a PRIME file descriptor and + vice versa. Drivers must use the kernel dma-buf buffer sharing framework + to manage the PRIME file descriptors. Similar to the mode setting + API PRIME is agnostic to the underlying buffer object manager, as + long as handles are 32bit unsigned integers. + </para> + <para> + While non-GEM drivers must implement the operations themselves, GEM + drivers must use the <function>drm_gem_prime_handle_to_fd</function> + and <function>drm_gem_prime_fd_to_handle</function> helper functions. + Those helpers rely on the driver + <methodname>gem_prime_export</methodname> and + <methodname>gem_prime_import</methodname> operations to create a dma-buf + instance from a GEM object (dma-buf exporter role) and to create a GEM + object from a dma-buf instance (dma-buf importer role). + </para> + <para> + <synopsis>struct dma_buf * (*gem_prime_export)(struct drm_device *dev, + struct drm_gem_object *obj, + int flags); struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev, - struct dma_buf *dma_buf);</synopsis> - These two operations are mandatory for GEM drivers that support - PRIME. - </para> - </sect3> - <sect3> - <title>PRIME Helper Functions</title> -!Pdrivers/gpu/drm/drm_prime.c PRIME Helpers + struct dma_buf *dma_buf);</synopsis> + These two operations are mandatory for GEM drivers that support + PRIME. + </para> </sect3> - </sect2> - <sect2> - <title>PRIME Function References</title> + <sect3> + <title>PRIME Helper Functions</title> +!Pdrivers/gpu/drm/drm_prime.c PRIME Helpers + </sect3> + </sect2> + <sect2> + <title>PRIME Function References</title> !Edrivers/gpu/drm/drm_prime.c - </sect2> - <sect2> - <title>DRM MM Range Allocator</title> - <sect3> - <title>Overview</title> + </sect2> + <sect2> + <title>DRM MM Range Allocator</title> + <sect3> + <title>Overview</title> !Pdrivers/gpu/drm/drm_mm.c Overview - </sect3> - <sect3> - <title>LRU Scan/Eviction Support</title> + </sect3> + <sect3> + <title>LRU Scan/Eviction Support</title> !Pdrivers/gpu/drm/drm_mm.c lru scan roaster - </sect3> + </sect3> </sect2> - <sect2> - <title>DRM MM Range Allocator Function References</title> + <sect2> + <title>DRM MM Range Allocator Function References</title> !Edrivers/gpu/drm/drm_mm.c !Iinclude/drm/drm_mm.h - </sect2> + </sect2> + <sect2> + <title>CMA Helper Functions Reference</title> +!Pdrivers/gpu/drm/drm_gem_cma_helper.c cma helpers +!Edrivers/gpu/drm/drm_gem_cma_helper.c +!Iinclude/drm/drm_gem_cma_helper.h + </sect2> </sect1> <!-- Internals: mode setting --> |