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 24 struct sync_timeline; 25 struct sync_pt; 26 struct 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 */ 51 struct 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 */ 91 struct 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 */ 118 struct 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 */ 146 struct 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 }; 161 162 /** 163 * struct sync_fence_waiter - metadata for asynchronous waiter on a fence 164 * @waiter_list: membership in sync_fence.waiter_list_head 165 * @callback: function pointer to call when fence signals 166 * @callback_data: pointer to pass to @callback 167 */ 168 struct sync_fence_waiter { 169 struct list_head waiter_list; 170 171 void (*callback)(struct sync_fence *fence, void *data); 172 void *callback_data; 173 }; 174 175 /* 176 * API for sync_timeline implementers 177 */ 178 179 /** 180 * sync_timeline_create() - creates a sync object 181 * @ops: specifies the implemention ops for the object 182 * @size: size to allocate for this obj 183 * @name: sync_timeline name 184 * 185 * Creates a new sync_timeline which will use the implemetation specified by 186 * @ops. @size bytes will be allocated allowing for implemntation specific 187 * data to be kept after the generic sync_timeline stuct. 188 */ 189 struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, 190 int size, const char *name); 191 192 /** 193 * sync_timeline_destory() - destorys a sync object 194 * @obj: sync_timeline to destroy 195 * 196 * A sync implemntation should call this when the @obj is going away 197 * (i.e. module unload.) @obj won't actually be freed until all its childern 198 * sync_pts are freed. 199 */ 200 void sync_timeline_destroy(struct sync_timeline *obj); 201 202 /** 203 * sync_timeline_signal() - signal a status change on a sync_timeline 204 * @obj: sync_timeline to signal 205 * 206 * A sync implemntation should call this any time one of it's sync_pts 207 * has signaled or has an error condition. 208 */ 209 void sync_timeline_signal(struct sync_timeline *obj); 210 211 /** 212 * sync_pt_create() - creates a sync pt 213 * @parent: sync_pt's parent sync_timeline 214 * @size: size to allocate for this pt 215 * 216 * Creates a new sync_pt as a chiled of @parent. @size bytes will be 217 * allocated allowing for implemntation specific data to be kept after 218 * the generic sync_timeline struct. 219 */ 220 struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size); 221 222 /** 223 * sync_pt_free() - frees a sync pt 224 * @pt: sync_pt to free 225 * 226 * This should only be called on sync_pts which have been created but 227 * not added to a fence. 228 */ 229 void sync_pt_free(struct sync_pt *pt); 230 231 /** 232 * sync_fence_create() - creates a sync fence 233 * @name: name of fence to create 234 * @pt: sync_pt to add to the fence 235 * 236 * Creates a fence containg @pt. Once this is called, the fence takes 237 * ownership of @pt. 238 */ 239 struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt); 240 241 /* 242 * API for sync_fence consumers 243 */ 244 245 /** 246 * sync_fence_merge() - merge two fences 247 * @name: name of new fence 248 * @a: fence a 249 * @b: fence b 250 * 251 * Creates a new fence which contains copies of all the sync_pts in both 252 * @a and @b. @a and @b remain valid, independent fences. 253 */ 254 struct sync_fence *sync_fence_merge(const char *name, 255 struct sync_fence *a, struct sync_fence *b); 256 257 /** 258 * sync_fence_fdget() - get a fence from an fd 259 * @fd: fd referencing a fence 260 * 261 * Ensures @fd references a valid fence, increments the refcount of the backing 262 * file, and returns the fence. 263 */ 264 struct sync_fence *sync_fence_fdget(int fd); 265 266 /** 267 * sync_fence_put() - puts a refernnce of a sync fence 268 * @fence: fence to put 269 * 270 * Puts a reference on @fence. If this is the last reference, the fence and 271 * all it's sync_pts will be freed 272 */ 273 void sync_fence_put(struct sync_fence *fence); 274 275 /** 276 * sync_fence_install() - installs a fence into a file descriptor 277 * @fence: fence to instal 278 * @fd: file descriptor in which to install the fence 279 * 280 * Installs @fence into @fd. @fd's should be acquired through get_unused_fd(). 281 */ 282 void sync_fence_install(struct sync_fence *fence, int fd); 283 284 /** 285 * sync_fence_wait_async() - registers and async wait on the fence 286 * @fence: fence to wait on 287 * @callback: callback 288 * @callback_data data to pass to the callback 289 * 290 * Returns 1 if @fence has already signaled. 291 * 292 * Registers a callback to be called when @fence signals or has an error 293 */ 294 int sync_fence_wait_async(struct sync_fence *fence, 295 void (*callback)(struct sync_fence *, void *data), 296 void *callback_data); 297 298 /** 299 * sync_fence_wait() - wait on fence 300 * @fence: fence to wait on 301 * @tiemout: timeout in ms 302 * 303 * Wait for @fence to be signaled or have an error. Waits indefintly 304 * if @timeout = 0 305 */ 306 int sync_fence_wait(struct sync_fence *fence, long timeout); 307 308 #endif /* __KERNEL__ */ 309 310 /** 311 * struct sync_merge_data - data passed to merge ioctl 312 * @fd2: file descriptor of second fence 313 * @name: name of new fence 314 * @fence: returns the fd of the new fence to userspace 315 */ 316 struct sync_merge_data { 317 __s32 fd2; /* fd of second fence */ 318 char name[32]; /* name of new fence */ 319 __s32 fence; /* fd on newly created fence */ 320 }; 321 322 /** 323 * struct sync_pt_info - detailed sync_pt information 324 * @len: length of sync_pt_info including any driver_data 325 * @obj_name: name of parent sync_timeline 326 * @driver_name: name of driver implmenting the parent 327 * @status: status of the sync_pt 0:active 1:signaled <0:error 328 * @timestamp_ns: timestamp of status change in nanoseconds 329 * @driver_data: any driver dependant data 330 */ 331 struct sync_pt_info { 332 __u32 len; 333 char obj_name[32]; 334 char driver_name[32]; 335 __s32 status; 336 __u64 timestamp_ns; 337 338 __u8 driver_data[0]; 339 }; 340 341 /** 342 * struct sync_fence_info_data - data returned from fence info ioctl 343 * @len: ioctl caller writes the size of the buffer its passing in. 344 * ioctl returns length of sync_fence_data reutnred to userspace 345 * including pt_info. 346 * @name: name of fence 347 * @status: status of fence. 1: signaled 0:active <0:error 348 * @pt_info: a sync_pt_info struct for every sync_pt in the fence 349 */ 350 struct sync_fence_info_data { 351 __u32 len; 352 char name[32]; 353 __s32 status; 354 355 __u8 pt_info[0]; 356 }; 357 358 #define SYNC_IOC_MAGIC '>' 359 360 /** 361 * DOC: SYNC_IOC_WAIT - wait for a fence to signal 362 * 363 * pass timeout in milliseconds. 364 */ 365 #define SYNC_IOC_WAIT _IOW(SYNC_IOC_MAGIC, 0, __u32) 366 367 /** 368 * DOC: SYNC_IOC_MERGE - merge two fences 369 * 370 * Takes a struct sync_merge_data. Creates a new fence containing copies of 371 * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the 372 * new fence's fd in sync_merge_data.fence 373 */ 374 #define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 1, struct sync_merge_data) 375 376 /** 377 * DOC: SYNC_IOC_FENCE_INFO - get detailed information on a fence 378 * 379 * Takes a struct sync_fence_info_data with extra space allocated for pt_info. 380 * Caller should write the size of the buffer into len. On return, len is 381 * updated to reflect the total size of the sync_fence_info_data including 382 * pt_info. 383 * 384 * pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence. 385 * To itterate over the sync_pt_infos, use the sync_pt_info.len field. 386 */ 387 #define SYNC_IOC_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2,\ 388 struct sync_fence_info_data) 389 390 #endif /* _LINUX_SYNC_H */ 391
