Re: [PATCH 11/24] drm/doc: Document drm_file.[hc]

Daniel Vetter
2017-03-14T13:27:06Z

On Mon, Mar 13, 2017 at 01:53:28PM -0400, Sean Paul wrote:
> On Wed, Mar 08, 2017 at 03:12:44PM +0100, Daniel Vetter wrote:
> > 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 since it's also really outdated - we clean up pending DRM events in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 was rather outdated this amounted to full-on rewrite.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.
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
>
> Overall, awesome patch, really does a good job explaining the parameters and how
> they interact with each other (bonus points for the lock breadcrumbs). I just
> have a few optional nits and some spelling errors.
>
> Reviewed-by: Sean Paul <seanpaul@chromium.org>

Merged up to this one to drm-misc. As mentioned a few times on irc, I'd
like to get the post/preclose patches through relevant driver trees, for
maximum amount of testing.
-Daniel
>
> > ---
> > Documentation/gpu/drm-internals.rst | 52 +------
> > Documentation/gpu/drm-uapi.rst | 4 +
> > drivers/gpu/drm/drm_file.c | 66 +++++----
> > include/drm/drm_drv.h | 81 ++++++++++-
> > include/drm/drm_file.h | 267 ++++++++++++++++++++++++++++++++----
> > 5 files changed, 356 insertions(+), 114 deletions(-)
> >
> > diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst
> > index ea329b71c459..7a2fe4a02212 100644
> > --- a/Documentation/gpu/drm-internals.rst
> > +++ b/Documentation/gpu/drm-internals.rst
> > @@ -246,61 +246,15 @@ drivers.
> > Open/Close, File Operations and IOCTLs
> > ======================================
> >
> > -Open and Close
> > ---------------
> > -
> > -Open and close handlers. None of those methods are mandatory::
> > -
> > - int (*firstopen) (struct drm_device *);
> > - void (*lastclose) (struct drm_device *);
> > - int (*open) (struct drm_device *, struct drm_file *);
> > - void (*preclose) (struct drm_device *, struct drm_file *);
> > - void (*postclose) (struct drm_device *, struct drm_file *);
> > -
> > -The firstopen method is called by the DRM core for legacy UMS (User Mode
> > -Setting) drivers only when an application opens a device that has no
> > -other opened file handle. UMS drivers can implement it to acquire device
> > -resources. KMS drivers can't use the method and must acquire resources
> > -in the load method instead.
> > -
> > -Similarly the lastclose method is called when the last application
> > -holding a file handle opened on the device closes it, for both UMS and
> > -KMS drivers. Additionally, the method is also called at module unload
> > -time or, for hot-pluggable devices, when the device is unplugged. The
> > -firstopen and lastclose calls can thus be unbalanced.
> > -
> > -The open method is called every time the device is opened by an
> > -application. Drivers can allocate per-file private data in this method
> > -and store them in the struct :c:type:`struct drm_file
> > -<drm_file>` driver_priv field. Note that the open method is
> > -called before firstopen.
> > -
> > -The close operation is split into preclose and postclose methods.
> > -Drivers must stop and cleanup all per-file operations in the preclose
> > -method. For instance pending vertical blanking and page flip events must
> > -be cancelled. No per-file operation is allowed on the file handle after
> > -returning from the preclose method.
> > -
> > -Finally the postclose method is called as the last step of the close
> > -operation, right before calling the lastclose method if no other open
> > -file handle exists for the device. Drivers that have allocated per-file
> > -private data in the open method should free it here.
> > -
> > -The lastclose method should restore CRTC and plane properties to default
> > -value, so that a subsequent open of the device will not inherit state
> > -from the previous user. It can also be used to execute delayed power
> > -switching state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
> > -infrastructure. Beyond that KMS drivers should not do any
> > -further cleanup. Only legacy UMS drivers might need to clean up device
> > -state so that the vga console or an independent fbdev driver could take
> > -over.
> > -
> > File Operations
> > ---------------
> >
> > .. kernel-doc:: drivers/gpu/drm/drm_file.c
> > :doc: file operations
> >
> > +.. kernel-doc:: include/drm/drm_file.h
> > + :internal:
> > +
> > .. kernel-doc:: drivers/gpu/drm/drm_file.c
> > :export:
> >
> > diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
> > index fcc228ef5bc4..352652810dab 100644
> > --- a/Documentation/gpu/drm-uapi.rst
> > +++ b/Documentation/gpu/drm-uapi.rst
> > @@ -21,6 +21,8 @@ libdrm Device Lookup
> > :doc: getunique and setversion story
> >
> >
> > +.. _drm_primary_node:
> > +
> > Primary Nodes, DRM Master and Authentication
> > ============================================
> >
> > @@ -103,6 +105,8 @@ is already rather painful for the DRM subsystem, with multiple different uAPIs
> > for the same thing co-existing. If we add a few more complete mistakes into the
> > mix every year it would be entirely unmanageable.
> >
> > +.. _drm_render_node:
> > +
> > Render nodes
> > ============
> >
> > diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> > index d9e63d73d3ec..a8813a1115dc 100644
> > --- a/drivers/gpu/drm/drm_file.c
> > +++ b/drivers/gpu/drm/drm_file.c
> > @@ -50,12 +50,14 @@ DEFINE_MUTEX(drm_global_mutex);
> > *
> > * Drivers must define the file operations structure that forms the DRM
> > * userspace API entry point, even though most of those operations are
> > - * implemented in the DRM core. The mandatory functions are drm_open(),
> > + * implemented in the DRM core. The resulting &struct file_operations must be
> > + * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
> > * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
> > - * (note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n). Drivers which
> > - * implement private ioctls that require 32/64 bit compatibility support must
> > - * provide their own .compat_ioctl() handler that processes private ioctls and
> > - * calls drm_compat_ioctl() for core ioctls.
> > + * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
> > + * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
> > + * that require 32/64 bit compatibility support must provide their own
> > + * &file_operations.compat_ioctl handler that processes private ioctls and calls
> > + * drm_compat_ioctl() for core ioctls.
> > *
> > * In addition drm_read() and drm_poll() provide support for DRM events. DRM
> > * events are a generic and extensible means to send asynchronous events to
> > @@ -63,10 +65,14 @@ DEFINE_MUTEX(drm_global_mutex);
> > * page flip completions by the KMS API. But drivers can also use it for their
> > * own needs, e.g. to signal completion of rendering.
> > *
> > + * For the driver-side event interface see drm_event_reserve_init() and
> > + * drm_send_event() as the main starting points.
> > + *
> > * The memory mapping implementation will vary depending on how the driver
> > * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
> > * function, modern drivers should use one of the provided memory-manager
> > - * specific implementations. For GEM-based drivers this is drm_gem_mmap().
> > + * specific implementations. For GEM-based drivers this is drm_gem_mmap(), and
> > + * for drivers which use the CMA GEM helpers it's drm_gem_cma_mmap().
> > *
> > * No other file operations are supported by the DRM userspace API. Overall the
> > * following is an example #file_operations structure::
> > @@ -82,6 +88,9 @@ DEFINE_MUTEX(drm_global_mutex);
> > * .llseek = no_llseek,
> > * .mmap = drm_gem_mmap,
> > * };
> > + *
> > + * FIXME: We should have a macro for this (and the CMA version) so that drivers
> > + * don't have to repeat it all the time.
> > */
> >
> > static int drm_open_helper(struct file *filp, struct drm_minor *minor);
> > @@ -111,9 +120,9 @@ static int drm_setup(struct drm_device * dev)
> > * @inode: device inode
> > * @filp: file pointer.
> > *
> > - * This function must be used by drivers as their .open() #file_operations
> > - * method. It looks up the correct DRM device and instantiates all the per-file
> > - * resources for it.
> > + * This function must be used by drivers as their &file_operations.open method.
> > + * It looks up the correct DRM device and instantiates all the per-file
> > + * resources for it. It also calls the &drm_driver.open driver callback.
> > *
> > * RETURNS:
> > *
> > @@ -298,11 +307,6 @@ static void drm_events_release(struct drm_file *file_priv)
> > spin_unlock_irqrestore(&dev->event_lock, flags);
> > }
> >
> > -/*
> > - * drm_legacy_dev_reinit
> > - *
> > - * Reinitializes a legacy/ums drm device in it's lastclose function.
> > - */
> > static void drm_legacy_dev_reinit(struct drm_device *dev)
> > {
> > if (dev->irq_enabled)
> > @@ -327,15 +331,6 @@ static void drm_legacy_dev_reinit(struct drm_device *dev)
> > DRM_DEBUG("lastclose completed\n");
> > }
> >
> > -/*
> > - * Take down the DRM device.
> > - *
> > - * \param dev DRM device structure.
> > - *
> > - * Frees every resource in \p dev.
> > - *
> > - * \sa drm_device
> > - */
> > void drm_lastclose(struct drm_device * dev)
> > {
> > DRM_DEBUG("\n");
> > @@ -353,9 +348,11 @@ void drm_lastclose(struct drm_device * dev)
> > * @inode: device inode
> > * @filp: file pointer.
> > *
> > - * This function must be used by drivers as their .release() #file_operations
> > - * method. It frees any resources associated with the open file, and if this is
> > - * the last open file for the DRM device also proceeds to call drm_lastclose().
> > + * This function must be used by drivers as their &file_operations.release
> > + * method. It frees any resources associated with the open file, and calls the
> > + * &drm_driver.preclose and &drm_driver.lastclose driver callbacks. If this is
> > + * the last open file for the DRM device also proceeds to call the
> > + * &drm_driver.lastclose driver callback.
> > *
> > * RETURNS:
> > *
> > @@ -443,13 +440,13 @@ EXPORT_SYMBOL(drm_release);
> > * @count: count in bytes to read
> > * @offset: offset to read
> > *
> > - * This function must be used by drivers as their .read() #file_operations
> > + * This function must be used by drivers as their &file_operations.read
> > * method iff they use DRM events for asynchronous signalling to userspace.
> > * Since events are used by the KMS API for vblank and page flip completion this
> > * means all modern display drivers must use it.
> > *
> > - * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
> > - * must set the .llseek() #file_operation to no_llseek(). Polling support is
> > + * @offset is ignored, DRM events are read like a pipe. Therefore drivers also
> > + * must set the &file_operation.llseek to no_llseek(). Polling support is
>
> nit: double space before 'to'
>
> > * provided by drm_poll().
> > *
> > * This function will only ever read a full event. Therefore userspace must
> > @@ -537,10 +534,10 @@ EXPORT_SYMBOL(drm_read);
> > * @filp: file pointer
> > * @wait: poll waiter table
> > *
> > - * This function must be used by drivers as their .read() #file_operations
> > - * method iff they use DRM events for asynchronous signalling to userspace.
> > - * Since events are used by the KMS API for vblank and page flip completion this
> > - * means all modern display drivers must use it.
> > + * This function must be used by drivers as their &file_operations.read method
> > + * iff they use DRM events for asynchronous signalling to userspace. Since
> > + * events are used by the KMS API for vblank and page flip completion this means
> > + * all modern display drivers must use it.
> > *
> > * See also drm_read().
> > *
> > @@ -650,7 +647,8 @@ EXPORT_SYMBOL(drm_event_reserve_init);
> > * @p: tracking structure for the pending event
> > *
> > * This function frees the event @p initialized with drm_event_reserve_init()
> > - * and releases any allocated space.
> > + * and releases any allocated space. It is used to cancel an event when the
> > + * nonblocking operation could not be submitted and needed to be aborted.
> > */
> > void drm_event_cancel_free(struct drm_device *dev,
> > struct drm_pending_event *p)
> > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> > index 4321d012c4ba..8f900fb30275 100644
> > --- a/include/drm/drm_drv.h
> > +++ b/include/drm/drm_drv.h
> > @@ -64,7 +64,6 @@ struct drm_mode_create_dumb;
> > * structure for GEM drivers.
> > */
> > struct drm_driver {
> > -
> > /**
> > * @load:
> > *
> > @@ -76,14 +75,94 @@ struct drm_driver {
> > * See drm_dev_init() and drm_dev_register() for proper and
> > * race-free way to set up a &struct drm_device.
> > *
> > + * This is deprecated, do not use!
> > + *
> > * Returns:
> > *
> > * Zero on success, non-zero value on failure.
> > */
> > int (*load) (struct drm_device *, unsigned long flags);
> > +
> > + /**
> > + * @open:
> > + *
> > + * Driver callback when a new &struct drm_file is opened. Useful for
> > + * setting up driver-private data structures like buffer allocators,
> > + * execution contexts or similar things. Such driver-private resources
> > + * must be released again in @postclose.
> > + *
> > + * Since the display/modeset side of DRM can only be owned by exactly
> > + * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
> > + * there should never be a need to set up any modeset related resources
> > + * in this callback. Doing so would be a driver design bug.
> > + *
> > + * Returns:
> > + *
> > + * 0 on success, a negative error code on failure, which will be
> > + * promoted to userspace as the result of the open() system call.
> > + */
> > int (*open) (struct drm_device *, struct drm_file *);
> > +
> > + /**
> > + * @preclose:
> > + *
> > + * One of the driver callbacks when a new &struct drm_file is closed.
> > + * Useful for tearing down driver-private data structures allocated in
> > + * @open like buffer allocators, execution contexts or similar things.
> > + *
> > + * Since the display/modeset side of DRM can only be owned by exactly
> > + * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
> > + * there should never be a need to tear down any modeset related
> > + * resources in this callback. Doing so would be a driver design bug.
> > + *
> > + * FIXME: It is not really clear why there's both @preclose and
> > + * @postclose. Without a really good reason, use @postclose only.
> > + */
> > void (*preclose) (struct drm_device *, struct drm_file *file_priv);
> > +
> > + /**
> > + * @postclose:
> > + *
> > + * One of the driver callbacks when a new &struct drm_file is closed.
> > + * Useful for tearing down driver-private data structures allocated in
> > + * @open like buffer allocators, execution contexts or similar things.
> > + *
> > + * Since the display/modeset side of DRM can only be owned by exactly
> > + * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
> > + * there should never be a need to tear down any modeset related
> > + * resources in this callback. Doing so would be a driver design bug.
> > + *
> > + * FIXME: It is not really clear why there's both @preclose and
> > + * @postclose. Without a really good reason, use @postclose only.
> > + */
> > void (*postclose) (struct drm_device *, struct drm_file *);
> > +
> > + /**
> > + * @lastclose:
> > + *
> > + * Called when the last &struct drm_file has been closed and there's
> > + * currently no userspace client for the &struct drm_device.
> > + *
> > + * Modern drivers should only use this to force-restore the fbdev
> > + * framebuffer using drm_fb_helper_restore_fbdev_mode_unlocked().
> > + * Anything else would indicate there's something seriously wrong.
> > + * Modern drivers can also use this to execute delayed power switching
> > + * state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
> > + * infrastructure.
> > + *
> > + * This is called after @preclose and @postclose have been called.
> > + *
> > + * NOTE:
> > + *
> > + * All legacy drivers use this callback to de-initialize the hardware.
> > + * This is purely because of the shadow-attach model, where the DRM
> > + * kernel driver does not really own the hardware. Instead ownershipe is
> > + * handled with the help of userspace through an inheritedly racy dance
> > + * to set/unset the VT into raw mode.
> > + *
> > + * Legacy drivers initialize the hardware in the @firstopen callback,
> > + * which isn't even called for modern drivers.
> > + */
> > void (*lastclose) (struct drm_device *);
> >
> > /**
> > diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> > index 4e347399a7bd..67244f2c0c54 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: */
>
> Same comment here re: the private comment. I don't think it adds anything beyond
> what you've already said in the overview.
>
> > + 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 +74,288 @@ 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
> > + * nonblcoking operations.
>
> nonblocking
>
> > + */
> > 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 per open file descriptor DRM state.
>
> nit: 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>`.
> > + */
> > +
>
> nit: extra line
>
> > 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
>
> nit: double space before Protected
>
> > + * &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;
> > +
> > +
>
> nit: extra line
>
> > + /** @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 devlivery to userspace
>
> Dat 'dev' muscle memory :-)
>
> > + * 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);
> > --
> > 2.11.0
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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