linux/include/drm/drm_file.h
Desmond Cheong Zhi Xi 649839d7cf drm: add lockdep assert to drm_is_current_master_locked
In drm_is_current_master_locked, accessing drm_file.master should be
protected by either drm_file.master_lookup_lock or
drm_device.master_mutex. This was previously awkward to assert with
lockdep.

Following patch ("locking/lockdep: Provide lockdep_assert{,_once}()
helpers"), this assertion is now convenient. So we add in the
assertion and explain this lock design in the kerneldoc.

Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210802105957.77692-3-desmondcheongzx@gmail.com
2021-08-05 12:08:15 +02:00

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C

/*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* Copyright (c) 2009-2010, Code Aurora Forum.
* All rights reserved.
*
* Author: Rickard E. (Rik) Faith <faith@valinux.com>
* Author: Gareth Hughes <gareth@valinux.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef _DRM_FILE_H_
#define _DRM_FILE_H_
#include <linux/types.h>
#include <linux/completion.h>
#include <linux/idr.h>
#include <uapi/drm/drm.h>
#include <drm/drm_prime.h>
struct dma_fence;
struct drm_file;
struct drm_device;
struct device;
struct file;
/*
* 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.
*/
/* Note that the order of this enum is ABI (it determines
* /dev/dri/renderD* numbers).
*/
enum drm_minor_type {
DRM_MINOR_PRIMARY,
DRM_MINOR_CONTROL,
DRM_MINOR_RENDER,
};
/**
* 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 {
/* private: */
int index; /* Minor device number */
int type; /* Control or render */
struct device *kdev; /* Linux device */
struct drm_device *dev;
struct dentry *debugfs_root;
struct list_head debugfs_list;
struct mutex debugfs_lock; /* Protects debugfs_list. */
};
/**
* struct drm_pending_event - Event queued up for userspace to read
*
* This represents a DRM event. Drivers can use this as a generic completion
* mechanism, which supports kernel-internal &struct completion, &struct dma_fence
* and also the DRM-specific &struct drm_event delivery mechanism.
*/
struct drm_pending_event {
/**
* @completion:
*
* Optional pointer to a kernel internal completion signalled when
* drm_send_event() is called, useful to internally synchronize with
* nonblocking operations.
*/
struct completion *completion;
/**
* @completion_release:
*
* Optional callback currently only used by the atomic modeset helpers
* to clean up the reference count for the structure @completion is
* stored in.
*/
void (*completion_release)(struct completion *completion);
/**
* @event:
*
* Pointer to the actual event that should be sent to userspace to be
* read using drm_read(). Can be optional, since nowadays events are
* also used to signal kernel internal threads with @completion or DMA
* transactions using @fence.
*/
struct drm_event *event;
/**
* @fence:
*
* Optional DMA fence to unblock other hardware transactions which
* depend upon the nonblocking DRM operation this event represents.
*/
struct dma_fence *fence;
/**
* @file_priv:
*
* &struct drm_file where @event should be delivered to. Only set when
* @event is set.
*/
struct drm_file *file_priv;
/**
* @link:
*
* Double-linked list to keep track of this event. Can be used by the
* driver up to the point when it calls drm_send_event(), after that
* this list entry is owned by the core for its own book-keeping.
*/
struct list_head link;
/**
* @pending_link:
*
* Entry on &drm_file.pending_event_list, to keep track of all pending
* events for @file_priv, to allow correct unwinding of them when
* userspace closes the file before the event is delivered.
*/
struct list_head pending_link;
};
/**
* struct drm_file - DRM file private data
*
* This structure tracks DRM state per open file descriptor.
*/
struct drm_file {
/**
* @authenticated:
*
* Whether the client is allowed to submit rendering, which for legacy
* nodes means it must be authenticated.
*
* See also the :ref:`section on primary nodes and authentication
* <drm_primary_node>`.
*/
bool authenticated;
/**
* @stereo_allowed:
*
* True when the client has asked us to expose stereo 3D mode flags.
*/
bool stereo_allowed;
/**
* @universal_planes:
*
* True if client understands CRTC primary planes and cursor planes
* in the plane list. Automatically set when @atomic is set.
*/
bool universal_planes;
/** @atomic: True if client understands atomic properties. */
bool atomic;
/**
* @aspect_ratio_allowed:
*
* True, if client can handle picture aspect ratios, and has requested
* to pass this information along with the mode.
*/
bool aspect_ratio_allowed;
/**
* @writeback_connectors:
*
* True if client understands writeback connectors
*/
bool writeback_connectors;
/**
* @was_master:
*
* This client has or had, master capability. Protected by struct
* &drm_device.master_mutex.
*
* This is used to ensure that CAP_SYS_ADMIN is not enforced, if the
* client is or was master in the past.
*/
bool was_master;
/**
* @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>`.
*/
bool is_master;
/**
* @master:
*
* Master this node is currently associated with. Protected by struct
* &drm_device.master_mutex, and serialized by @master_lookup_lock.
*
* 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.
*
* To update @master, both &drm_device.master_mutex and
* @master_lookup_lock need to be held, therefore holding either of
* them is safe and enough for the read side.
*
* When dereferencing this pointer, either hold struct
* &drm_device.master_mutex for the duration of the pointer's use, or
* use drm_file_get_master() if struct &drm_device.master_mutex is not
* currently held and there is no other need to hold it. This prevents
* @master from being freed during use.
*
* See also @authentication and @is_master and the :ref:`section on
* primary nodes and authentication <drm_primary_node>`.
*/
struct drm_master *master;
/** @master_lock: Serializes @master. */
spinlock_t master_lookup_lock;
/** @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;
/**
* @object_idr:
*
* Mapping of mm object handles to object pointers. Used by the GEM
* subsystem. Protected by @table_lock.
*/
struct idr object_idr;
/** @table_lock: Protects @object_idr. */
spinlock_t table_lock;
/** @syncobj_idr: Mapping of sync object handles to object pointers. */
struct idr syncobj_idr;
/** @syncobj_table_lock: Protects @syncobj_idr. */
spinlock_t syncobj_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;
/**
* @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 framebuffer object to prevent it from untimely disappearing.
*/
struct list_head fbs;
/** @fbs_lock: Protects @fbs. */
struct mutex fbs_lock;
/**
* @blobs:
*
* User-created blob properties; this retains a reference on the
* property.
*
* Protected by @drm_mode_config.blob_lock;
*/
struct list_head blobs;
/** @event_wait: Waitqueue for new events added to @event_list. */
wait_queue_head_t event_wait;
/**
* @pending_event_list:
*
* List of pending &struct drm_pending_event, used to clean up pending
* events in case this file gets closed before the event is signalled.
* Uses the &drm_pending_event.pending_link entry.
*
* Protect by &drm_device.event_lock.
*/
struct list_head pending_event_list;
/**
* @event_list:
*
* List of &struct drm_pending_event, ready for delivery to userspace
* through drm_read(). Uses the &drm_pending_event.link entry.
*
* Protect by &drm_device.event_lock.
*/
struct list_head event_list;
/**
* @event_space:
*
* Available event space to prevent userspace from
* exhausting kernel memory. Currently limited to the fairly arbitrary
* value of 4KB.
*/
int event_space;
/** @event_read_lock: Serializes drm_read(). */
struct mutex event_read_lock;
/**
* @prime:
*
* Per-file buffer caches used by the PRIME buffer sharing code.
*/
struct drm_prime_file_private prime;
/* private: */
#if IS_ENABLED(CONFIG_DRM_LEGACY)
unsigned long lock_count; /* DRI1 legacy lock count */
#endif
};
/**
* 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;
}
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);
int drm_release(struct inode *inode, struct file *filp);
int drm_release_noglobal(struct inode *inode, struct file *filp);
__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait);
int drm_event_reserve_init_locked(struct drm_device *dev,
struct drm_file *file_priv,
struct drm_pending_event *p,
struct drm_event *e);
int drm_event_reserve_init(struct drm_device *dev,
struct drm_file *file_priv,
struct drm_pending_event *p,
struct drm_event *e);
void drm_event_cancel_free(struct drm_device *dev,
struct drm_pending_event *p);
void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e);
void drm_send_event(struct drm_device *dev, struct drm_pending_event *e);
void drm_send_event_timestamp_locked(struct drm_device *dev,
struct drm_pending_event *e,
ktime_t timestamp);
struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);
#ifdef CONFIG_MMU
struct drm_vma_offset_manager;
unsigned long drm_get_unmapped_area(struct file *file,
unsigned long uaddr, unsigned long len,
unsigned long pgoff, unsigned long flags,
struct drm_vma_offset_manager *mgr);
#endif /* CONFIG_MMU */
#endif /* _DRM_FILE_H_ */