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drm: Update GEM refcounting docs 

I just realized that I've forgotten to update all the gem refcounting
docs. For pennance also add pretty docs for the overall drm_gem_object
structure, with a few links thrown in fore good.

As usually we need to make sure the kerneldoc reference is at most a
sect2 for otherwise it won't be listed.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1445533889-7661-1-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Daniel Vetter 2015-10-22 19:11:27 +02:00
parent 1ec218373b
commit decc60bf49
2 changed files with 100 additions and 21 deletions
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15
Documentation/DocBook/gpu.tmpl
View File

@ -635,10 +635,10 @@ char *date;</synopsis>
acquired and release by <function>calling drm_gem_object_reference</function>
and <function>drm_gem_object_unreference</function> respectively. The
caller must hold the <structname>drm_device</structname>
<structfield>struct_mutex</structfield> lock. As a convenience, GEM
provides the <function>drm_gem_object_reference_unlocked</function> and
<function>drm_gem_object_unreference_unlocked</function> functions that
can be called without holding the lock.
<structfield>struct_mutex</structfield> lock when calling
<function>drm_gem_object_reference</function>. As a convenience, GEM
provides <function>drm_gem_object_unreference_unlocked</function>
functions that can be called without holding the lock.
</para>
<para>
When the last reference to a GEM object is released the GEM core calls
@ -836,10 +836,11 @@ char *date;</synopsis>
abstracted from the client in libdrm.
</para>
</sect3>
<sect3>
<title>GEM Function Reference</title>
</sect2>
<sect2>
<title>GEM Function Reference</title>
!Edrivers/gpu/drm/drm_gem.c
</sect3>
!Iinclude/drm/drm_gem.h
</sect2>
<sect2>
<title>VMA Offset Manager</title>

106
include/drm/drm_gem.h
View File

@ -35,76 +35,129 @@
*/
/**
* This structure defines the drm_mm memory object, which will be used by the
* DRM for its buffer objects.
* struct drm_gem_object - GEM buffer object
*
* This structure defines the generic parts for GEM buffer objects, which are
* mostly around handling mmap and userspace handles.
*
* Buffer objects are often abbreviated to BO.
*/
struct drm_gem_object {
/** Reference count of this object */
/**
* @refcount:
*
* Reference count of this object
*
* Please use drm_gem_object_reference() to acquire and
* drm_gem_object_unreference() or drm_gem_object_unreference_unlocked()
* to release a reference to a GEM buffer object.
*/
struct kref refcount;
/**
* handle_count - gem file_priv handle count of this object
* @handle_count:
*
* This is the GEM file_priv handle count of this object.
*
* Each handle also holds a reference. Note that when the handle_count
* drops to 0 any global names (e.g. the id in the flink namespace) will
* be cleared.
*
* Protected by dev->object_name_lock.
* */
*/
unsigned handle_count;
/** Related drm device */
/**
* @dev: DRM dev this object belongs to.
*/
struct drm_device *dev;
/** File representing the shmem storage */
/**
* @filp:
*
* SHMEM file node used as backing storage for swappable buffer objects.
* GEM also supports driver private objects with driver-specific backing
* storage (contiguous CMA memory, special reserved blocks). In this
* case @filp is NULL.
*/
struct file *filp;
/* Mapping info for this object */
/**
* @vma_node:
*
* Mapping info for this object to support mmap. Drivers are supposed to
* allocate the mmap offset using drm_gem_create_mmap_offset(). The
* offset itself can be retrieved using drm_vma_node_offset_addr().
*
* Memory mapping itself is handled by drm_gem_mmap(), which also checks
* that userspace is allowed to access the object.
*/
struct drm_vma_offset_node vma_node;
/**
* @size:
*
* Size of the object, in bytes. Immutable over the object's
* lifetime.
*/
size_t size;
/**
* @name:
*
* Global name for this object, starts at 1. 0 means unnamed.
* Access is covered by the object_name_lock in the related drm_device
* Access is covered by dev->object_name_lock. This is used by the GEM_FLINK
* and GEM_OPEN ioctls.
*/
int name;
/**
* Memory domains. These monitor which caches contain read/write data
* @read_domains:
*
* Read memory domains. These monitor which caches contain read/write data
* related to the object. When transitioning from one set of domains
* to another, the driver is called to ensure that caches are suitably
* flushed and invalidated
* flushed and invalidated.
*/
uint32_t read_domains;
/**
* @write_domain: Corresponding unique write memory domain.
*/
uint32_t write_domain;
/**
* @pending_read_domains:
*
* While validating an exec operation, the
* new read/write domain values are computed here.
* They will be transferred to the above values
* at the point that any cache flushing occurs
*/
uint32_t pending_read_domains;
/**
* @pending_write_domain: Write domain similar to @pending_read_domains.
*/
uint32_t pending_write_domain;
/**
* dma_buf - dma buf associated with this GEM object
* @dma_buf:
*
* dma-buf associated with this GEM object.
*
* Pointer to the dma-buf associated with this gem object (either
* through importing or exporting). We break the resulting reference
* loop when the last gem handle for this object is released.
*
* Protected by obj->object_name_lock
* Protected by obj->object_name_lock.
*/
struct dma_buf *dma_buf;
/**
* import_attach - dma buf attachment backing this object
* @import_attach:
*
* dma-buf attachment backing this object.
*
* Any foreign dma_buf imported as a gem object has this set to the
* attachment point for the device. This is invariant over the lifetime
@ -133,12 +186,30 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
struct vm_area_struct *vma);
int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
/**
* drm_gem_object_reference - acquire a GEM BO reference
* @obj: GEM buffer object
*
* This acquires additional reference to @obj. It is illegal to call this
* without already holding a reference. No locks required.
*/
static inline void
drm_gem_object_reference(struct drm_gem_object *obj)
{
kref_get(&obj->refcount);
}
/**
* drm_gem_object_unreference - release a GEM BO reference
* @obj: GEM buffer object
*
* This releases a reference to @obj. Callers must hold the dev->struct_mutex
* lock when calling this function, even when the driver doesn't use
* dev->struct_mutex for anything.
*
* For drivers not encumbered with legacy locking use
* drm_gem_object_unreference_unlocked() instead.
*/
static inline void
drm_gem_object_unreference(struct drm_gem_object *obj)
{
@ -149,6 +220,13 @@ drm_gem_object_unreference(struct drm_gem_object *obj)
}
}
/**
* drm_gem_object_unreference_unlocked - release a GEM BO reference
* @obj: GEM buffer object
*
* This releases a reference to @obj. Callers must not hold the
* dev->struct_mutex lock when calling this function.
*/
static inline void
drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
{