sync.h revision af7582f293cdc29999d05f75b1ec835ffa43cb68
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 */ 47struct sync_timeline_ops { 48 const char *driver_name; 49 50 /* required */ 51 struct sync_pt *(*dup)(struct sync_pt *pt); 52 53 /* required */ 54 int (*has_signaled)(struct sync_pt *pt); 55 56 /* required */ 57 int (*compare)(struct sync_pt *a, struct sync_pt *b); 58 59 /* optional */ 60 void (*free_pt)(struct sync_pt *sync_pt); 61 62 /* optional */ 63 void (*release_obj)(struct sync_timeline *sync_timeline); 64 65 /* optional */ 66 void (*print_obj)(struct seq_file *s, 67 struct sync_timeline *sync_timeline); 68 69 /* optional */ 70 void (*print_pt)(struct seq_file *s, struct sync_pt *sync_pt); 71}; 72 73/** 74 * struct sync_timeline - sync object 75 * @ops: ops that define the implementaiton of the sync_timeline 76 * @name: name of the sync_timeline. Useful for debugging 77 * @destoryed: set when sync_timeline is destroyed 78 * @child_list_head: list of children sync_pts for this sync_timeline 79 * @child_list_lock: lock protecting @child_list_head, destroyed, and 80 * sync_pt.status 81 * @active_list_head: list of active (unsignaled/errored) sync_pts 82 * @sync_timeline_list: membership in global sync_timeline_list 83 */ 84struct sync_timeline { 85 const struct sync_timeline_ops *ops; 86 char name[32]; 87 88 /* protected by child_list_lock */ 89 bool destroyed; 90 91 struct list_head child_list_head; 92 spinlock_t child_list_lock; 93 94 struct list_head active_list_head; 95 spinlock_t active_list_lock; 96 97 struct list_head sync_timeline_list; 98}; 99 100/** 101 * struct sync_pt - sync point 102 * @parent: sync_timeline to which this sync_pt belongs 103 * @child_list: membership in sync_timeline.child_list_head 104 * @active_list: membership in sync_timeline.active_list_head 105 * @fence: sync_fence to which the sync_pt belongs 106 * @pt_list: membership in sync_fence.pt_list_head 107 * @status: 1: signaled, 0:active, <0: error 108 * @timestamp: time which sync_pt status transitioned from active to 109 * singaled or error. 110 */ 111struct sync_pt { 112 struct sync_timeline *parent; 113 struct list_head child_list; 114 115 struct list_head active_list; 116 117 struct sync_fence *fence; 118 struct list_head pt_list; 119 120 /* protected by parent->active_list_lock */ 121 int status; 122 123 ktime_t timestamp; 124}; 125 126/** 127 * struct sync_fence - sync fence 128 * @file: file representing this fence 129 * @name: name of sync_fence. Useful for debugging 130 * @pt_list_head: list of sync_pts in ths fence. immutable once fence 131 * is created 132 * @waiter_list_head: list of asynchronous waiters on this fence 133 * @waiter_list_lock: lock protecting @waiter_list_head and @status 134 * @status: 1: signaled, 0:active, <0: error 135 * 136 * @wq: wait queue for fence signaling 137 * @sync_fence_list: membership in global fence list 138 */ 139struct sync_fence { 140 struct file *file; 141 char name[32]; 142 143 /* this list is immutable once the fence is created */ 144 struct list_head pt_list_head; 145 146 struct list_head waiter_list_head; 147 spinlock_t waiter_list_lock; /* also protects status */ 148 int status; 149 150 wait_queue_head_t wq; 151 152 struct list_head sync_fence_list; 153}; 154 155/** 156 * struct sync_fence_waiter - metadata for asynchronous waiter on a fence 157 * @waiter_list: membership in sync_fence.waiter_list_head 158 * @callback: function pointer to call when fence signals 159 * @callback_data: pointer to pass to @callback 160 */ 161struct sync_fence_waiter { 162 struct list_head waiter_list; 163 164 void (*callback)(struct sync_fence *fence, void *data); 165 void *callback_data; 166}; 167 168/* 169 * API for sync_timeline implementers 170 */ 171 172/** 173 * sync_timeline_create() - creates a sync object 174 * @ops: specifies the implemention ops for the object 175 * @size: size to allocate for this obj 176 * @name: sync_timeline name 177 * 178 * Creates a new sync_timeline which will use the implemetation specified by 179 * @ops. @size bytes will be allocated allowing for implemntation specific 180 * data to be kept after the generic sync_timeline stuct. 181 */ 182struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops, 183 int size, const char *name); 184 185/** 186 * sync_timeline_destory() - destorys a sync object 187 * @obj: sync_timeline to destroy 188 * 189 * A sync implemntation should call this when the @obj is going away 190 * (i.e. module unload.) @obj won't actually be freed until all its childern 191 * sync_pts are freed. 192 */ 193void sync_timeline_destroy(struct sync_timeline *obj); 194 195/** 196 * sync_timeline_signal() - signal a status change on a sync_timeline 197 * @obj: sync_timeline to signal 198 * 199 * A sync implemntation should call this any time one of it's sync_pts 200 * has signaled or has an error condition. 201 */ 202void sync_timeline_signal(struct sync_timeline *obj); 203 204/** 205 * sync_pt_create() - creates a sync pt 206 * @parent: sync_pt's parent sync_timeline 207 * @size: size to allocate for this pt 208 * 209 * Creates a new sync_pt as a chiled of @parent. @size bytes will be 210 * allocated allowing for implemntation specific data to be kept after 211 * the generic sync_timeline struct. 212 */ 213struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size); 214 215/** 216 * sync_pt_free() - frees a sync pt 217 * @pt: sync_pt to free 218 * 219 * This should only be called on sync_pts which have been created but 220 * not added to a fence. 221 */ 222void sync_pt_free(struct sync_pt *pt); 223 224/** 225 * sync_fence_create() - creates a sync fence 226 * @name: name of fence to create 227 * @pt: sync_pt to add to the fence 228 * 229 * Creates a fence containg @pt. Once this is called, the fence takes 230 * ownership of @pt. 231 */ 232struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt); 233 234/* 235 * API for sync_fence consumers 236 */ 237 238/** 239 * sync_fence_merge() - merge two fences 240 * @name: name of new fence 241 * @a: fence a 242 * @b: fence b 243 * 244 * Creates a new fence which contains copies of all the sync_pts in both 245 * @a and @b. @a and @b remain valid, independent fences. 246 */ 247struct sync_fence *sync_fence_merge(const char *name, 248 struct sync_fence *a, struct sync_fence *b); 249 250/** 251 * sync_fence_fdget() - get a fence from an fd 252 * @fd: fd referencing a fence 253 * 254 * Ensures @fd references a valid fence, increments the refcount of the backing 255 * file, and returns the fence. 256 */ 257struct sync_fence *sync_fence_fdget(int fd); 258 259/** 260 * sync_fence_put() - puts a refernnce of a sync fence 261 * @fence: fence to put 262 * 263 * Puts a reference on @fence. If this is the last reference, the fence and 264 * all it's sync_pts will be freed 265 */ 266void sync_fence_put(struct sync_fence *fence); 267 268/** 269 * sync_fence_install() - installs a fence into a file descriptor 270 * @fence: fence to instal 271 * @fd: file descriptor in which to install the fence 272 * 273 * Installs @fence into @fd. @fd's should be acquired through get_unused_fd(). 274 */ 275void sync_fence_install(struct sync_fence *fence, int fd); 276 277/** 278 * sync_fence_wait_async() - registers and async wait on the fence 279 * @fence: fence to wait on 280 * @callback: callback 281 * @callback_data data to pass to the callback 282 * 283 * Returns 1 if @fence has already signaled. 284 * 285 * Registers a callback to be called when @fence signals or has an error 286 */ 287int sync_fence_wait_async(struct sync_fence *fence, 288 void (*callback)(struct sync_fence *, void *data), 289 void *callback_data); 290 291/** 292 * sync_fence_wait() - wait on fence 293 * @fence: fence to wait on 294 * @tiemout: timeout in ms 295 * 296 * Wait for @fence to be signaled or have an error. Waits indefintly 297 * if @timeout = 0 298 */ 299int sync_fence_wait(struct sync_fence *fence, long timeout); 300 301#endif /* __KERNEL__ */ 302 303/** 304 * struct sync_merge_data - data passed to merge ioctl 305 * @fd2: file descriptor of second fence 306 * @name: name of new fence 307 * @fence: returns the fd of the new fence to userspace 308 */ 309struct sync_merge_data { 310 __s32 fd2; /* fd of second fence */ 311 char name[32]; /* name of new fence */ 312 __s32 fence; /* fd on newly created fence */ 313}; 314 315#define SYNC_IOC_MAGIC '>' 316 317/** 318 * DOC: SYNC_IOC_WAIT - wait for a fence to signal 319 * 320 * pass timeout in milliseconds. 321 */ 322#define SYNC_IOC_WAIT _IOW(SYNC_IOC_MAGIC, 0, __u32) 323 324/** 325 * DOC: SYNC_IOC_MERGE - merge two fences 326 * 327 * Takes a struct sync_merge_data. Creates a new fence containing copies of 328 * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the 329 * new fence's fd in sync_merge_data.fence 330 */ 331#define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 1, struct sync_merge_data) 332 333#endif /* _LINUX_SYNC_H */ 334