| Message ID | 20170308141257.12119-12-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 since it's also really outdated - we clean up pending DRM events in 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 was rather outdated this amounted to full-on rewrite.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> > --- > 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
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> Fixed all the nits, except for /* private: */, as explained, that's just kernel-doc markup to annotate internal structure stuff that users shouldn't look at. Thanks a lot for your careful read-through, Daniel
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
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 * 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: */ + 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. + */ 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. + */ 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 devlivery 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);
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> --- 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(-)