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Diffstat (limited to 'include/linux/sync.h')
| -rw-r--r-- | include/linux/sync.h | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/include/linux/sync.h b/include/linux/sync.h new file mode 100644 index 00000000..38ea986d --- /dev/null +++ b/include/linux/sync.h @@ -0,0 +1,426 @@ +/* + * include/linux/sync.h + * + * Copyright (C) 2012 Google, Inc. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#ifndef _LINUX_SYNC_H +#define _LINUX_SYNC_H + +#include <linux/types.h> +#ifdef __KERNEL__ + +#include <linux/kref.h> +#include <linux/ktime.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/wait.h> + +struct sync_timeline; +struct sync_pt; +struct sync_fence; + +/** + * struct sync_timeline_ops - sync object implementation ops + * @driver_name: name of the implentation + * @dup: duplicate a sync_pt + * @has_signaled: returns: + * 1 if pt has signaled + * 0 if pt has not signaled + * <0 on error + * @compare: returns: + * 1 if b will signal before a + * 0 if a and b will signal at the same time + * -1 if a will signabl before b + * @free_pt: called before sync_pt is freed + * @release_obj: called before sync_timeline is freed + * @print_obj: deprecated + * @print_pt: deprecated + * @fill_driver_data: write implmentation specific driver data to data. + * should return an error if there is not enough room + * as specified by size. This information is returned + * to userspace by SYNC_IOC_FENCE_INFO. + * @timeline_value_str: fill str with the value of the sync_timeline's counter + * @pt_value_str: fill str with the value of the sync_pt + */ +struct sync_timeline_ops { + const char *driver_name; + + /* required */ + struct sync_pt *(*dup)(struct sync_pt *pt); + + /* required */ + int (*has_signaled)(struct sync_pt *pt); + + /* required */ + int (*compare)(struct sync_pt *a, struct sync_pt *b); + + /* optional */ + void (*free_pt)(struct sync_pt *sync_pt); + + /* optional */ + void (*release_obj)(struct sync_timeline *sync_timeline); + + /* deprecated */ + void (*print_obj)(struct seq_file *s, + struct sync_timeline *sync_timeline); + + /* deprecated */ + void (*print_pt)(struct seq_file *s, struct sync_pt *sync_pt); + + /* optional */ + int (*fill_driver_data)(struct sync_pt *syncpt, void *data, int size); + + /* optional */ + void (*timeline_value_str)(struct sync_timeline *timeline, char *str, + int size); + + /* optional */ + void (*pt_value_str)(struct sync_pt *pt, char *str, int size); +}; + +/** + * struct sync_timeline - sync object + * @kref: reference count on fence. + * @ops: ops that define the implementaiton of the sync_timeline + * @name: name of the sync_timeline. Useful for debugging + * @destoryed: set when sync_timeline is destroyed + * @child_list_head: list of children sync_pts for this sync_timeline + * @child_list_lock: lock protecting @child_list_head, destroyed, and + * sync_pt.status + * @active_list_head: list of active (unsignaled/errored) sync_pts + * @sync_timeline_list: membership in global sync_timeline_list + */ +struct sync_timeline { + struct kref kref; + const struct sync_timeline_ops *ops; + char name[32]; + + /* protected by child_list_lock */ + bool destroyed; + + struct list_head child_list_head; + spinlock_t child_list_lock; + + struct list_head active_list_head; + spinlock_t active_list_lock; + + struct list_head sync_timeline_list; +}; + +/** + * struct sync_pt - sync point + * @parent: sync_timeline to which this sync_pt belongs + * @child_list: membership in sync_timeline.child_list_head + * @active_list: membership in sync_timeline.active_list_head + * @signaled_list: membership in temorary signaled_list on stack + * @fence: sync_fence to which the sync_pt belongs + * @pt_list: membership in sync_fence.pt_list_head + * @status: 1: signaled, 0:active, <0: error + * @timestamp: time which sync_pt status transitioned from active to + * singaled or error. + */ +struct sync_pt { + struct sync_timeline *parent; + struct list_head child_list; + + struct list_head active_list; + struct list_head signaled_list; + + struct sync_fence *fence; + struct list_head pt_list; + + /* protected by parent->active_list_lock */ + int status; + + ktime_t timestamp; +}; + +/** + * struct sync_fence - sync fence + * @file: file representing this fence + * @kref: referenace count on fence. + * @name: name of sync_fence. Useful for debugging + * @pt_list_head: list of sync_pts in ths fence. immutable once fence + * is created + * @waiter_list_head: list of asynchronous waiters on this fence + * @waiter_list_lock: lock protecting @waiter_list_head and @status + * @status: 1: signaled, 0:active, <0: error + * + * @wq: wait queue for fence signaling + * @sync_fence_list: membership in global fence list + */ +struct sync_fence { + struct file *file; + struct kref kref; + char name[32]; + + /* this list is immutable once the fence is created */ + struct list_head pt_list_head; + + struct list_head waiter_list_head; + spinlock_t waiter_list_lock; /* also protects status */ + int status; + + wait_queue_head_t wq; + + struct list_head sync_fence_list; +}; + +struct sync_fence_waiter; +typedef void (*sync_callback_t)(struct sync_fence *fence, + struct sync_fence_waiter *waiter); + +/** + * struct sync_fence_waiter - metadata for asynchronous waiter on a fence + * @waiter_list: membership in sync_fence.waiter_list_head + * @callback: function pointer to call when fence signals + * @callback_data: pointer to pass to @callback + */ +struct sync_fence_waiter { + struct list_head waiter_list; + + sync_callback_t callback; +}; + +static inline void sync_fence_waiter_init(struct sync_fence_waiter *waiter, + sync_callback_t callback) +{ + waiter->callback = callback; +} + +/* + * API for sync_timeline implementers + */ + +/** + * sync_timeline_create() - creates a sync object + * @ops: specifies the implemention ops for the object + * @size: size to allocate for this obj + * @name: sync_timeline name + * + * Creates a new sync_timeline which will use the implemetation specified by + * @ops. @size bytes will be allocated allowing for implemntation specific + * data to be kept after the generic sync_timeline stuct. + */ +struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, + int size, const char *name); + +/** + * sync_timeline_destory() - destorys a sync object + * @obj: sync_timeline to destroy + * + * A sync implemntation should call this when the @obj is going away + * (i.e. module unload.) @obj won't actually be freed until all its childern + * sync_pts are freed. + */ +void sync_timeline_destroy(struct sync_timeline *obj); + +/** + * sync_timeline_signal() - signal a status change on a sync_timeline + * @obj: sync_timeline to signal + * + * A sync implemntation should call this any time one of it's sync_pts + * has signaled or has an error condition. + */ +void sync_timeline_signal(struct sync_timeline *obj); + +/** + * sync_pt_create() - creates a sync pt + * @parent: sync_pt's parent sync_timeline + * @size: size to allocate for this pt + * + * Creates a new sync_pt as a chiled of @parent. @size bytes will be + * allocated allowing for implemntation specific data to be kept after + * the generic sync_timeline struct. + */ +struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size); + +/** + * sync_pt_free() - frees a sync pt + * @pt: sync_pt to free + * + * This should only be called on sync_pts which have been created but + * not added to a fence. + */ +void sync_pt_free(struct sync_pt *pt); + +/** + * sync_fence_create() - creates a sync fence + * @name: name of fence to create + * @pt: sync_pt to add to the fence + * + * Creates a fence containg @pt. Once this is called, the fence takes + * ownership of @pt. + */ +struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt); + +/* + * API for sync_fence consumers + */ + +/** + * sync_fence_merge() - merge two fences + * @name: name of new fence + * @a: fence a + * @b: fence b + * + * Creates a new fence which contains copies of all the sync_pts in both + * @a and @b. @a and @b remain valid, independent fences. + */ +struct sync_fence *sync_fence_merge(const char *name, + struct sync_fence *a, struct sync_fence *b); + +/** + * sync_fence_fdget() - get a fence from an fd + * @fd: fd referencing a fence + * + * Ensures @fd references a valid fence, increments the refcount of the backing + * file, and returns the fence. + */ +struct sync_fence *sync_fence_fdget(int fd); + +/** + * sync_fence_put() - puts a refernnce of a sync fence + * @fence: fence to put + * + * Puts a reference on @fence. If this is the last reference, the fence and + * all it's sync_pts will be freed + */ +void sync_fence_put(struct sync_fence *fence); + +/** + * sync_fence_install() - installs a fence into a file descriptor + * @fence: fence to instal + * @fd: file descriptor in which to install the fence + * + * Installs @fence into @fd. @fd's should be acquired through get_unused_fd(). + */ +void sync_fence_install(struct sync_fence *fence, int fd); + +/** + * sync_fence_wait_async() - registers and async wait on the fence + * @fence: fence to wait on + * @waiter: waiter callback struck + * + * Returns 1 if @fence has already signaled. + * + * Registers a callback to be called when @fence signals or has an error. + * @waiter should be initialized with sync_fence_waiter_init(). + */ +int sync_fence_wait_async(struct sync_fence *fence, + struct sync_fence_waiter *waiter); + +/** + * sync_fence_cancel_async() - cancels an async wait + * @fence: fence to wait on + * @waiter: waiter callback struck + * + * returns 0 if waiter was removed from fence's async waiter list. + * returns -ENOENT if waiter was not found on fence's async waiter list. + * + * Cancels a previously registered async wait. Will fail gracefully if + * @waiter was never registered or if @fence has already signaled @waiter. + */ +int sync_fence_cancel_async(struct sync_fence *fence, + struct sync_fence_waiter *waiter); + +/** + * sync_fence_wait() - wait on fence + * @fence: fence to wait on + * @tiemout: timeout in ms + * + * Wait for @fence to be signaled or have an error. Waits indefinitely + * if @timeout < 0 + */ +int sync_fence_wait(struct sync_fence *fence, long timeout); + +#endif /* __KERNEL__ */ + +/** + * struct sync_merge_data - data passed to merge ioctl + * @fd2: file descriptor of second fence + * @name: name of new fence + * @fence: returns the fd of the new fence to userspace + */ +struct sync_merge_data { + __s32 fd2; /* fd of second fence */ + char name[32]; /* name of new fence */ + __s32 fence; /* fd on newly created fence */ +}; + +/** + * struct sync_pt_info - detailed sync_pt information + * @len: length of sync_pt_info including any driver_data + * @obj_name: name of parent sync_timeline + * @driver_name: name of driver implmenting the parent + * @status: status of the sync_pt 0:active 1:signaled <0:error + * @timestamp_ns: timestamp of status change in nanoseconds + * @driver_data: any driver dependant data + */ +struct sync_pt_info { + __u32 len; + char obj_name[32]; + char driver_name[32]; + __s32 status; + __u64 timestamp_ns; + + __u8 driver_data[0]; +}; + +/** + * struct sync_fence_info_data - data returned from fence info ioctl + * @len: ioctl caller writes the size of the buffer its passing in. + * ioctl returns length of sync_fence_data reutnred to userspace + * including pt_info. + * @name: name of fence + * @status: status of fence. 1: signaled 0:active <0:error + * @pt_info: a sync_pt_info struct for every sync_pt in the fence + */ +struct sync_fence_info_data { + __u32 len; + char name[32]; + __s32 status; + + __u8 pt_info[0]; +}; + +#define SYNC_IOC_MAGIC '>' + +/** + * DOC: SYNC_IOC_WAIT - wait for a fence to signal + * + * pass timeout in milliseconds. Waits indefinitely timeout < 0. + */ +#define SYNC_IOC_WAIT _IOW(SYNC_IOC_MAGIC, 0, __s32) + +/** + * DOC: SYNC_IOC_MERGE - merge two fences + * + * Takes a struct sync_merge_data. Creates a new fence containing copies of + * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the + * new fence's fd in sync_merge_data.fence + */ +#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 1, struct sync_merge_data) + +/** + * DOC: SYNC_IOC_FENCE_INFO - get detailed information on a fence + * + * Takes a struct sync_fence_info_data with extra space allocated for pt_info. + * Caller should write the size of the buffer into len. On return, len is + * updated to reflect the total size of the sync_fence_info_data including + * pt_info. + * + * pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence. + * To itterate over the sync_pt_infos, use the sync_pt_info.len field. + */ +#define SYNC_IOC_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2,\ + struct sync_fence_info_data) + +#endif /* _LINUX_SYNC_H */ |