summaryrefslogtreecommitdiffstats
path: root/include/drm/drm_file.h
diff options
context:
space:
mode:
authorDaniel Vetter <daniel.vetter@ffwll.ch>2017-03-08 15:12:44 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-03-14 14:38:33 +0100
commitb93658f83fa7f89cde5cfba7158da2be8cac42b2 (patch)
treefd39bd7cc02e2d6f40734b252474c0265af3ab81 /include/drm/drm_file.h
parent7d52cb88c9ca20c32288de6ed62b32410c936ccc (diff)
downloadlinux-b93658f83fa7f89cde5cfba7158da2be8cac42b2.tar.bz2
drm/doc: Document drm_file.[hc]
Well, mostly drm_file.h, and clean up all related things: - I didnt' figure out the difference between preclose and postclose. The existing explanation in drm-internals.rst didn't convince me, since it's also really outdated - we clean up pending DRM events in the core nowadays. I put a FIXME in for the future. - Another FIXME is to have a macro for default fops. - Lots of links all around, main areas are to tie the overview in drm_file.c more into the callbacks in struct drm_device, and the other is to link render/primary node code to the right sections in drm-uapi.rst. - Also moved the open/close stuff to drm_drv.h from drm-internals.rst, seems like the better place for that information. Since that section was rather outdated this amounted to full-on rewrite. A big missing piece here is some overview graph, but I think better to wait with that one until drm_device and drm_driver are also fully documented. v2: Nits from Sean. Reviewed-by: Sean Paul <seanpaul@chromium.org> Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170308141257.12119-12-daniel.vetter@ffwll.ch
Diffstat (limited to 'include/drm/drm_file.h')
-rw-r--r--include/drm/drm_file.h265
1 files changed, 235 insertions, 30 deletions
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 4e347399a7bd..5dd27ae5c47c 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -45,6 +45,7 @@ struct drm_device;
* FIXME: Not sure we want to have drm_minor here in the end, but to avoid
* header include loops we need it here for now.
*/
+
enum drm_minor_type {
DRM_MINOR_PRIMARY,
DRM_MINOR_CONTROL,
@@ -52,12 +53,19 @@ enum drm_minor_type {
};
/**
- * DRM minor structure. This structure represents a drm minor number.
+ * struct drm_minor - DRM device minor structure
+ *
+ * This structure represents a DRM minor number for device nodes in /dev.
+ * Entirely opaque to drivers and should never be inspected directly by drivers.
+ * Drivers instead should only interact with &struct drm_file and of course
+ * &struct drm_device, which is also where driver-private data and resources can
+ * be attached to.
*/
struct drm_minor {
- int index; /**< Minor device number */
- int type; /**< Control or render */
- struct device *kdev; /**< Linux device */
+ /* private: */
+ int index; /* Minor device number */
+ int type; /* Control or render */
+ struct device *kdev; /* Linux device */
struct drm_device *dev;
struct dentry *debugfs_root;
@@ -66,89 +74,286 @@ struct drm_minor {
struct mutex debugfs_lock; /* Protects debugfs_list. */
};
-/* Event queued up for userspace to read */
+/**
+ * struct drm_pending_event - Event queued up for userspace to read
+ *
+ * This represents a DRM event. Drivers can use this as a generic completion
+ * mechanism, which supports kernel-internal &struct completion, &struct dma_fence
+ * and also the DRM-specific &struct drm_event delivery mechanism.
+ */
struct drm_pending_event {
+ /**
+ * @completion:
+ *
+ * Optional pointer to a kernel internal completion signalled when
+ * drm_send_event() is called, useful to internally synchronize with
+ * nonblocking operations.
+ */
struct completion *completion;
+
+ /**
+ * @completion_release:
+ *
+ * Optional callback currently only used by the atomic modeset helpers
+ * to clean up the reference count for the structure @completion is
+ * stored in.
+ */
void (*completion_release)(struct completion *completion);
+
+ /**
+ * @event:
+ *
+ * Pointer to the actual event that should be sent to userspace to be
+ * read using drm_read(). Can be optional, since nowadays events are
+ * also used to signal kernel internal threads with @completion or DMA
+ * transactions using @fence.
+ */
struct drm_event *event;
+
+ /**
+ * @fence:
+ *
+ * Optional DMA fence to unblock other hardware transactions which
+ * depend upon the nonblocking DRM operation this event represents.
+ */
struct dma_fence *fence;
+
+ /**
+ * @file_priv:
+ *
+ * &struct drm_file where @event should be delivered to. Only set when
+ * @event is set.
+ */
+ struct drm_file *file_priv;
+
+ /**
+ * @link:
+ *
+ * Double-linked list to keep track of this event. Can be used by the
+ * driver up to the point when it calls drm_send_event(), after that
+ * this list entry is owned by the core for its own book-keeping.
+ */
struct list_head link;
+
+ /**
+ * @pending_link:
+ *
+ * Entry on &drm_file.pending_event_list, to keep track of all pending
+ * events for @file_priv, to allow correct unwinding of them when
+ * userspace closes the file before the event is delivered.
+ */
struct list_head pending_link;
- struct drm_file *file_priv;
};
-/** File private data */
+/**
+ * struct drm_file - DRM file private data
+ *
+ * This structure tracks DRM state per open file descriptor.
+ */
struct drm_file {
+ /**
+ * @authenticated:
+ *
+ * Whether the client is allowed to submit rendering, which for legacy
+ * nodes means it must be authenticated.
+ *
+ * See also the :ref:`section on primary nodes and authentication
+ * <drm_primary_node>`.
+ */
unsigned authenticated :1;
- /* true when the client has asked us to expose stereo 3D mode flags */
+
+ /**
+ * @stereo_allowed:
+ *
+ * True when the client has asked us to expose stereo 3D mode flags.
+ */
unsigned stereo_allowed :1;
- /*
- * true if client understands CRTC primary planes and cursor planes
- * in the plane list
+
+ /**
+ * @universal_planes:
+ *
+ * True if client understands CRTC primary planes and cursor planes
+ * in the plane list. Automatically set when @atomic is set.
*/
unsigned universal_planes:1;
- /* true if client understands atomic properties */
+
+ /** @atomic: True if client understands atomic properties. */
unsigned atomic:1;
- /*
- * This client is the creator of @master.
- * Protected by struct drm_device::master_mutex.
+
+ /**
+ * @is_master:
+ *
+ * This client is the creator of @master. Protected by struct
+ * &drm_device.master_mutex.
+ *
+ * See also the :ref:`section on primary nodes and authentication
+ * <drm_primary_node>`.
*/
unsigned is_master:1;
+ /**
+ * @master:
+ *
+ * Master this node is currently associated with. Only relevant if
+ * drm_is_primary_client() returns true. Note that this only
+ * matches &drm_device.master if the master is the currently active one.
+ *
+ * See also @authentication and @is_master and the :ref:`section on
+ * primary nodes and authentication <drm_primary_node>`.
+ */
+ struct drm_master *master;
+
+ /** @pid: Process that opened this file. */
struct pid *pid;
+
+ /** @magic: Authentication magic, see @authenticated. */
drm_magic_t magic;
+
+ /**
+ * @lhead:
+ *
+ * List of all open files of a DRM device, linked into
+ * &drm_device.filelist. Protected by &drm_device.filelist_mutex.
+ */
struct list_head lhead;
+
+ /** @minor: &struct drm_minor for this file. */
struct drm_minor *minor;
- unsigned long lock_count;
- /** Mapping of mm object handles to object pointers. */
+ /**
+ * @object_idr:
+ *
+ * Mapping of mm object handles to object pointers. Used by the GEM
+ * subsystem. Protected by @table_lock.
+ */
struct idr object_idr;
- /** Lock for synchronization of access to object_idr. */
+
+ /** @table_lock: Protects @object_idr. */
spinlock_t table_lock;
+ /** @filp: Pointer to the core file structure. */
struct file *filp;
+
+ /**
+ * @driver_priv:
+ *
+ * Optional pointer for driver private data. Can be allocated in
+ * &drm_driver.open and should be freed in &drm_driver.postclose.
+ */
void *driver_priv;
- struct drm_master *master; /* master this node is currently associated with
- N.B. not always dev->master */
/**
- * fbs - List of framebuffers associated with this file.
+ * @fbs:
+ *
+ * List of &struct drm_framebuffer associated with this file, using the
+ * &drm_framebuffer.filp_head entry.
*
- * Protected by fbs_lock. Note that the fbs list holds a reference on
- * the fb object to prevent it from untimely disappearing.
+ * Protected by @fbs_lock. Note that the @fbs list holds a reference on
+ * the framebuffer object to prevent it from untimely disappearing.
*/
struct list_head fbs;
+
+ /** @fbs_lock: Protects @fbs. */
struct mutex fbs_lock;
- /** User-created blob properties; this retains a reference on the
- * property. */
+ /**
+ * @blobs:
+ *
+ * User-created blob properties; this retains a reference on the
+ * property.
+ *
+ * Protected by @drm_mode_config.blob_lock;
+ */
struct list_head blobs;
+ /** @event_wait: Waitqueue for new events added to @event_list. */
wait_queue_head_t event_wait;
+
+ /**
+ * @pending_event_list:
+ *
+ * List of pending &struct drm_pending_event, used to clean up pending
+ * events in case this file gets closed before the event is signalled.
+ * Uses the &drm_pending_event.pending_link entry.
+ *
+ * Protect by &drm_device.event_lock.
+ */
struct list_head pending_event_list;
+
+ /**
+ * @event_list:
+ *
+ * List of &struct drm_pending_event, ready for delivery to userspace
+ * through drm_read(). Uses the &drm_pending_event.link entry.
+ *
+ * Protect by &drm_device.event_lock.
+ */
struct list_head event_list;
+
+ /**
+ * @event_space:
+ *
+ * Available event space to prevent userspace from
+ * exhausting kernel memory. Currently limited to the fairly arbitrary
+ * value of 4KB.
+ */
int event_space;
+ /** @event_read_lock: Serializes drm_read(). */
struct mutex event_read_lock;
+ /**
+ * @prime:
+ *
+ * Per-file buffer caches used by the PRIME buffer sharing code.
+ */
struct drm_prime_file_private prime;
+
+ /* private: */
+ unsigned long lock_count; /* DRI1 legacy lock count */
};
+/**
+ * drm_is_primary_client - is this an open file of the primary node
+ * @file_priv: DRM file
+ *
+ * Returns true if this is an open file of the primary node, i.e.
+ * &drm_file.minor of @file_priv is a primary minor.
+ *
+ * See also the :ref:`section on primary nodes and authentication
+ * <drm_primary_node>`.
+ */
+static inline bool drm_is_primary_client(const struct drm_file *file_priv)
+{
+ return file_priv->minor->type == DRM_MINOR_PRIMARY;
+}
+
+/**
+ * drm_is_render_client - is this an open file of the render node
+ * @file_priv: DRM file
+ *
+ * Returns true if this is an open file of the render node, i.e.
+ * &drm_file.minor of @file_priv is a render minor.
+ *
+ * See also the :ref:`section on render nodes <drm_render_node>`.
+ */
static inline bool drm_is_render_client(const struct drm_file *file_priv)
{
return file_priv->minor->type == DRM_MINOR_RENDER;
}
+/**
+ * drm_is_control_client - is this an open file of the control node
+ * @file_priv: DRM file
+ *
+ * Control nodes are deprecated and in the process of getting removed from the
+ * DRM userspace API. Do not ever use!
+ */
static inline bool drm_is_control_client(const struct drm_file *file_priv)
{
return file_priv->minor->type == DRM_MINOR_CONTROL;
}
-static inline bool drm_is_primary_client(const struct drm_file *file_priv)
-{
- return file_priv->minor->type == DRM_MINOR_PRIMARY;
-}
-
int drm_open(struct inode *inode, struct file *filp);
ssize_t drm_read(struct file *filp, char __user *buffer,
size_t count, loff_t *offset);