sync.h revision c0f61a4e6145728153d0b94152b4dd5b06899b3b
1/* 2 * include/linux/sync.h 3 * 4 * Copyright (C) 2012 Google, Inc. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 */ 12 13#ifndef _LINUX_SYNC_H 14#define _LINUX_SYNC_H 15 16#include <linux/types.h> 17#ifdef __KERNEL__ 18 19#include <linux/ktime.h> 20#include <linux/list.h> 21#include <linux/spinlock.h> 22#include <linux/wait.h> 23 24struct sync_timeline; 25struct sync_pt; 26struct sync_fence; 27 28/** 29 * struct sync_timeline_ops - sync object implementation ops 30 * @driver_name: name of the implentation 31 * @dup: duplicate a sync_pt 32 * @has_signaled: returns: 33 * 1 if pt has signaled 34 * 0 if pt has not signaled 35 * <0 on error 36 * @compare: returns: 37 * 1 if b will signal before a 38 * 0 if a and b will signal at the same time 39 * -1 if a will signabl before b 40 * @free_pt: called before sync_pt is freed 41 * @release_obj: called before sync_timeline is freed 42 * @print_obj: print aditional debug information about sync_timeline. 43 * should not print a newline 44 * @print_pt: print aditional debug information about sync_pt. 45 * should not print a newline 46 * @fill_driver_data: write implmentation specific driver data to data. 47 * should return an error if there is not enough room 48 * as specified by size. This information is returned 49 * to userspace by SYNC_IOC_FENCE_INFO. 50 */ 51struct sync_timeline_ops { 52 const char *driver_name; 53 54 /* required */ 55 struct sync_pt *(*dup)(struct sync_pt *pt); 56 57 /* required */ 58 int (*has_signaled)(struct sync_pt *pt); 59 60 /* required */ 61 int (*compare)(struct sync_pt *a, struct sync_pt *b); 62 63 /* optional */ 64 void (*free_pt)(struct sync_pt *sync_pt); 65 66 /* optional */ 67 void (*release_obj)(struct sync_timeline *sync_timeline); 68 69 /* optional */ 70 void (*print_obj)(struct seq_file *s, 71 struct sync_timeline *sync_timeline); 72 73 /* optional */ 74 void (*print_pt)(struct seq_file *s, struct sync_pt *sync_pt); 75 76 /* optional */ 77 int (*fill_driver_data)(struct sync_pt *syncpt, void *data, int size); 78}; 79 80/** 81 * struct sync_timeline - sync object 82 * @ops: ops that define the implementaiton of the sync_timeline 83 * @name: name of the sync_timeline. Useful for debugging 84 * @destoryed: set when sync_timeline is destroyed 85 * @child_list_head: list of children sync_pts for this sync_timeline 86 * @child_list_lock: lock protecting @child_list_head, destroyed, and 87 * sync_pt.status 88 * @active_list_head: list of active (unsignaled/errored) sync_pts 89 * @sync_timeline_list: membership in global sync_timeline_list 90 */ 91struct sync_timeline { 92 const struct sync_timeline_ops *ops; 93 char name[32]; 94 95 /* protected by child_list_lock */ 96 bool destroyed; 97 98 struct list_head child_list_head; 99 spinlock_t child_list_lock; 100 101 struct list_head active_list_head; 102 spinlock_t active_list_lock; 103 104 struct list_head sync_timeline_list; 105}; 106 107/** 108 * struct sync_pt - sync point 109 * @parent: sync_timeline to which this sync_pt belongs 110 * @child_list: membership in sync_timeline.child_list_head 111 * @active_list: membership in sync_timeline.active_list_head 112 * @fence: sync_fence to which the sync_pt belongs 113 * @pt_list: membership in sync_fence.pt_list_head 114 * @status: 1: signaled, 0:active, <0: error 115 * @timestamp: time which sync_pt status transitioned from active to 116 * singaled or error. 117 */ 118struct sync_pt { 119 struct sync_timeline *parent; 120 struct list_head child_list; 121 122 struct list_head active_list; 123 124 struct sync_fence *fence; 125 struct list_head pt_list; 126 127 /* protected by parent->active_list_lock */ 128 int status; 129 130 ktime_t timestamp; 131}; 132 133/** 134 * struct sync_fence - sync fence 135 * @file: file representing this fence 136 * @name: name of sync_fence. Useful for debugging 137 * @pt_list_head: list of sync_pts in ths fence. immutable once fence 138 * is created 139 * @waiter_list_head: list of asynchronous waiters on this fence 140 * @waiter_list_lock: lock protecting @waiter_list_head and @status 141 * @status: 1: signaled, 0:active, <0: error 142 * 143 * @wq: wait queue for fence signaling 144 * @sync_fence_list: membership in global fence list 145 */ 146struct sync_fence { 147 struct file *file; 148 char name[32]; 149 150 /* this list is immutable once the fence is created */ 151 struct list_head pt_list_head; 152 153 struct list_head waiter_list_head; 154 spinlock_t waiter_list_lock; /* also protects status */ 155 int status; 156 157 wait_queue_head_t wq; 158 159 struct list_head sync_fence_list; 160}; 161 162struct sync_fence_waiter; 163typedef void (*sync_callback_t)(struct sync_fence *fence, 164 struct sync_fence_waiter *waiter); 165 166/** 167 * struct sync_fence_waiter - metadata for asynchronous waiter on a fence 168 * @waiter_list: membership in sync_fence.waiter_list_head 169 * @callback: function pointer to call when fence signals 170 * @callback_data: pointer to pass to @callback 171 */ 172struct sync_fence_waiter { 173 struct list_head waiter_list; 174 175 sync_callback_t callback; 176}; 177 178static inline void sync_fence_waiter_init(struct sync_fence_waiter *waiter, 179 sync_callback_t callback) 180{ 181 waiter->callback = callback; 182} 183 184/* 185 * API for sync_timeline implementers 186 */ 187 188/** 189 * sync_timeline_create() - creates a sync object 190 * @ops: specifies the implemention ops for the object 191 * @size: size to allocate for this obj 192 * @name: sync_timeline name 193 * 194 * Creates a new sync_timeline which will use the implemetation specified by 195 * @ops. @size bytes will be allocated allowing for implemntation specific 196 * data to be kept after the generic sync_timeline stuct. 197 */ 198struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, 199 int size, const char *name); 200 201/** 202 * sync_timeline_destory() - destorys a sync object 203 * @obj: sync_timeline to destroy 204 * 205 * A sync implemntation should call this when the @obj is going away 206 * (i.e. module unload.) @obj won't actually be freed until all its childern 207 * sync_pts are freed. 208 */ 209void sync_timeline_destroy(struct sync_timeline *obj); 210 211/** 212 * sync_timeline_signal() - signal a status change on a sync_timeline 213 * @obj: sync_timeline to signal 214 * 215 * A sync implemntation should call this any time one of it's sync_pts 216 * has signaled or has an error condition. 217 */ 218void sync_timeline_signal(struct sync_timeline *obj); 219 220/** 221 * sync_pt_create() - creates a sync pt 222 * @parent: sync_pt's parent sync_timeline 223 * @size: size to allocate for this pt 224 * 225 * Creates a new sync_pt as a chiled of @parent. @size bytes will be 226 * allocated allowing for implemntation specific data to be kept after 227 * the generic sync_timeline struct. 228 */ 229struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size); 230 231/** 232 * sync_pt_free() - frees a sync pt 233 * @pt: sync_pt to free 234 * 235 * This should only be called on sync_pts which have been created but 236 * not added to a fence. 237 */ 238void sync_pt_free(struct sync_pt *pt); 239 240/** 241 * sync_fence_create() - creates a sync fence 242 * @name: name of fence to create 243 * @pt: sync_pt to add to the fence 244 * 245 * Creates a fence containg @pt. Once this is called, the fence takes 246 * ownership of @pt. 247 */ 248struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt); 249 250/* 251 * API for sync_fence consumers 252 */ 253 254/** 255 * sync_fence_merge() - merge two fences 256 * @name: name of new fence 257 * @a: fence a 258 * @b: fence b 259 * 260 * Creates a new fence which contains copies of all the sync_pts in both 261 * @a and @b. @a and @b remain valid, independent fences. 262 */ 263struct sync_fence *sync_fence_merge(const char *name, 264 struct sync_fence *a, struct sync_fence *b); 265 266/** 267 * sync_fence_fdget() - get a fence from an fd 268 * @fd: fd referencing a fence 269 * 270 * Ensures @fd references a valid fence, increments the refcount of the backing 271 * file, and returns the fence. 272 */ 273struct sync_fence *sync_fence_fdget(int fd); 274 275/** 276 * sync_fence_put() - puts a refernnce of a sync fence 277 * @fence: fence to put 278 * 279 * Puts a reference on @fence. If this is the last reference, the fence and 280 * all it's sync_pts will be freed 281 */ 282void sync_fence_put(struct sync_fence *fence); 283 284/** 285 * sync_fence_install() - installs a fence into a file descriptor 286 * @fence: fence to instal 287 * @fd: file descriptor in which to install the fence 288 * 289 * Installs @fence into @fd. @fd's should be acquired through get_unused_fd(). 290 */ 291void sync_fence_install(struct sync_fence *fence, int fd); 292 293/** 294 * sync_fence_wait_async() - registers and async wait on the fence 295 * @fence: fence to wait on 296 * @waiter: waiter callback struck 297 * 298 * Returns 1 if @fence has already signaled. 299 * 300 * Registers a callback to be called when @fence signals or has an error. 301 * @waiter should be initialized with sync_fence_waiter_init(). 302 */ 303int sync_fence_wait_async(struct sync_fence *fence, 304 struct sync_fence_waiter *waiter); 305 306/** 307 * sync_fence_cancel_async() - cancels an async wait 308 * @fence: fence to wait on 309 * @waiter: waiter callback struck 310 * 311 * returns 0 if waiter was removed from fence's async waiter list. 312 * returns -ENOENT if waiter was not found on fence's async waiter list. 313 * 314 * Cancels a previously registered async wait. Will fail gracefully if 315 * @waiter was never registered or if @fence has already signaled @waiter. 316 */ 317int sync_fence_cancel_async(struct sync_fence *fence, 318 struct sync_fence_waiter *waiter); 319 320/** 321 * sync_fence_wait() - wait on fence 322 * @fence: fence to wait on 323 * @tiemout: timeout in ms 324 * 325 * Wait for @fence to be signaled or have an error. Waits indefintly 326 * if @timeout = 0 327 */ 328int sync_fence_wait(struct sync_fence *fence, long timeout); 329 330#endif /* __KERNEL__ */ 331 332/** 333 * struct sync_merge_data - data passed to merge ioctl 334 * @fd2: file descriptor of second fence 335 * @name: name of new fence 336 * @fence: returns the fd of the new fence to userspace 337 */ 338struct sync_merge_data { 339 __s32 fd2; /* fd of second fence */ 340 char name[32]; /* name of new fence */ 341 __s32 fence; /* fd on newly created fence */ 342}; 343 344/** 345 * struct sync_pt_info - detailed sync_pt information 346 * @len: length of sync_pt_info including any driver_data 347 * @obj_name: name of parent sync_timeline 348 * @driver_name: name of driver implmenting the parent 349 * @status: status of the sync_pt 0:active 1:signaled <0:error 350 * @timestamp_ns: timestamp of status change in nanoseconds 351 * @driver_data: any driver dependant data 352 */ 353struct sync_pt_info { 354 __u32 len; 355 char obj_name[32]; 356 char driver_name[32]; 357 __s32 status; 358 __u64 timestamp_ns; 359 360 __u8 driver_data[0]; 361}; 362 363/** 364 * struct sync_fence_info_data - data returned from fence info ioctl 365 * @len: ioctl caller writes the size of the buffer its passing in. 366 * ioctl returns length of sync_fence_data reutnred to userspace 367 * including pt_info. 368 * @name: name of fence 369 * @status: status of fence. 1: signaled 0:active <0:error 370 * @pt_info: a sync_pt_info struct for every sync_pt in the fence 371 */ 372struct sync_fence_info_data { 373 __u32 len; 374 char name[32]; 375 __s32 status; 376 377 __u8 pt_info[0]; 378}; 379 380#define SYNC_IOC_MAGIC '>' 381 382/** 383 * DOC: SYNC_IOC_WAIT - wait for a fence to signal 384 * 385 * pass timeout in milliseconds. 386 */ 387#define SYNC_IOC_WAIT _IOW(SYNC_IOC_MAGIC, 0, __u32) 388 389/** 390 * DOC: SYNC_IOC_MERGE - merge two fences 391 * 392 * Takes a struct sync_merge_data. Creates a new fence containing copies of 393 * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the 394 * new fence's fd in sync_merge_data.fence 395 */ 396#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 1, struct sync_merge_data) 397 398/** 399 * DOC: SYNC_IOC_FENCE_INFO - get detailed information on a fence 400 * 401 * Takes a struct sync_fence_info_data with extra space allocated for pt_info. 402 * Caller should write the size of the buffer into len. On return, len is 403 * updated to reflect the total size of the sync_fence_info_data including 404 * pt_info. 405 * 406 * pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence. 407 * To itterate over the sync_pt_infos, use the sync_pt_info.len field. 408 */ 409#define SYNC_IOC_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2,\ 410 struct sync_fence_info_data) 411 412#endif /* _LINUX_SYNC_H */ 413