1 /* 2 * sync.c 3 * 4 * Copyright 2012 Google, Inc 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 #include <errno.h> 20 #include <fcntl.h> 21 #include <malloc.h> 22 #include <poll.h> 23 #include <stdatomic.h> 24 #include <stdint.h> 25 #include <string.h> 26 27 #include <sys/ioctl.h> 28 #include <sys/stat.h> 29 #include <sys/types.h> 30 31 #include <android/sync.h> 32 33 /* Legacy Sync API */ 34 35 struct sync_legacy_merge_data { 36 int32_t fd2; 37 char name[32]; 38 int32_t fence; 39 }; 40 41 /** 42 * DOC: SYNC_IOC_MERGE - merge two fences 43 * 44 * Takes a struct sync_merge_data. Creates a new fence containing copies of 45 * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the 46 * new fence's fd in sync_merge_data.fence 47 * 48 * This is the legacy version of the Sync API before the de-stage that happened 49 * on Linux kernel 4.7. 50 */ 51 #define SYNC_IOC_LEGACY_MERGE _IOWR(SYNC_IOC_MAGIC, 1, \ 52 struct sync_legacy_merge_data) 53 54 /** 55 * DOC: SYNC_IOC_LEGACY_FENCE_INFO - get detailed information on a fence 56 * 57 * Takes a struct sync_fence_info_data with extra space allocated for pt_info. 58 * Caller should write the size of the buffer into len. On return, len is 59 * updated to reflect the total size of the sync_fence_info_data including 60 * pt_info. 61 * 62 * pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence. 63 * To iterate over the sync_pt_infos, use the sync_pt_info.len field. 64 * 65 * This is the legacy version of the Sync API before the de-stage that happened 66 * on Linux kernel 4.7. 67 */ 68 #define SYNC_IOC_LEGACY_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2,\ 69 struct sync_fence_info_data) 70 71 /* SW Sync API */ 72 73 struct sw_sync_create_fence_data { 74 __u32 value; 75 char name[32]; 76 __s32 fence; 77 }; 78 79 #define SW_SYNC_IOC_MAGIC 'W' 80 #define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0, struct sw_sync_create_fence_data) 81 #define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32) 82 83 // --------------------------------------------------------------------------- 84 // Support for caching the sync uapi version. 85 // 86 // This library supports both legacy (android/staging) uapi and modern 87 // (mainline) sync uapi. Library calls first try one uapi, and if that fails, 88 // try the other. Since any given kernel only supports one uapi version, after 89 // the first successful syscall we know what the kernel supports and can skip 90 // trying the other. 91 92 enum uapi_version { 93 UAPI_UNKNOWN, 94 UAPI_MODERN, 95 UAPI_LEGACY 96 }; 97 static atomic_int g_uapi_version = ATOMIC_VAR_INIT(UAPI_UNKNOWN); 98 99 // --------------------------------------------------------------------------- 100 101 int sync_wait(int fd, int timeout) 102 { 103 struct pollfd fds; 104 int ret; 105 106 if (fd < 0) { 107 errno = EINVAL; 108 return -1; 109 } 110 111 fds.fd = fd; 112 fds.events = POLLIN; 113 114 do { 115 ret = poll(&fds, 1, timeout); 116 if (ret > 0) { 117 if (fds.revents & (POLLERR | POLLNVAL)) { 118 errno = EINVAL; 119 return -1; 120 } 121 return 0; 122 } else if (ret == 0) { 123 errno = ETIME; 124 return -1; 125 } 126 } while (ret == -1 && (errno == EINTR || errno == EAGAIN)); 127 128 return ret; 129 } 130 131 static int legacy_sync_merge(const char *name, int fd1, int fd2) 132 { 133 struct sync_legacy_merge_data data; 134 int ret; 135 136 data.fd2 = fd2; 137 strlcpy(data.name, name, sizeof(data.name)); 138 ret = ioctl(fd1, SYNC_IOC_LEGACY_MERGE, &data); 139 if (ret < 0) 140 return ret; 141 return data.fence; 142 } 143 144 static int modern_sync_merge(const char *name, int fd1, int fd2) 145 { 146 struct sync_merge_data data; 147 int ret; 148 149 data.fd2 = fd2; 150 strlcpy(data.name, name, sizeof(data.name)); 151 data.flags = 0; 152 data.pad = 0; 153 154 ret = ioctl(fd1, SYNC_IOC_MERGE, &data); 155 if (ret < 0) 156 return ret; 157 return data.fence; 158 } 159 160 int sync_merge(const char *name, int fd1, int fd2) 161 { 162 int uapi; 163 int ret; 164 165 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire); 166 167 if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) { 168 ret = modern_sync_merge(name, fd1, fd2); 169 if (ret >= 0 || errno != ENOTTY) { 170 if (ret >= 0 && uapi == UAPI_UNKNOWN) { 171 atomic_store_explicit(&g_uapi_version, UAPI_MODERN, 172 memory_order_release); 173 } 174 return ret; 175 } 176 } 177 178 ret = legacy_sync_merge(name, fd1, fd2); 179 if (ret >= 0 && uapi == UAPI_UNKNOWN) { 180 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY, 181 memory_order_release); 182 } 183 return ret; 184 } 185 186 static struct sync_fence_info_data *legacy_sync_fence_info(int fd) 187 { 188 struct sync_fence_info_data *legacy_info; 189 struct sync_pt_info *legacy_pt_info; 190 int err; 191 192 legacy_info = malloc(4096); 193 if (legacy_info == NULL) 194 return NULL; 195 196 legacy_info->len = 4096; 197 err = ioctl(fd, SYNC_IOC_LEGACY_FENCE_INFO, legacy_info); 198 if (err < 0) { 199 free(legacy_info); 200 return NULL; 201 } 202 return legacy_info; 203 } 204 205 static struct sync_file_info *modern_sync_file_info(int fd) 206 { 207 struct sync_file_info local_info; 208 struct sync_file_info *info; 209 int err; 210 211 memset(&local_info, 0, sizeof(local_info)); 212 err = ioctl(fd, SYNC_IOC_FILE_INFO, &local_info); 213 if (err < 0) 214 return NULL; 215 216 info = calloc(1, sizeof(struct sync_file_info) + 217 local_info.num_fences * sizeof(struct sync_fence_info)); 218 if (!info) 219 return NULL; 220 info->sync_fence_info = (__u64)(uintptr_t)(info + 1); 221 222 err = ioctl(fd, SYNC_IOC_FILE_INFO, info); 223 if (err < 0) { 224 free(info); 225 return NULL; 226 } 227 228 return info; 229 } 230 231 static struct sync_fence_info_data *sync_file_info_to_legacy_fence_info( 232 const struct sync_file_info *info) 233 { 234 struct sync_fence_info_data *legacy_info; 235 struct sync_pt_info *legacy_pt_info; 236 const struct sync_fence_info *fence_info = sync_get_fence_info(info); 237 const uint32_t num_fences = info->num_fences; 238 239 legacy_info = malloc(4096); 240 if (legacy_info == NULL) 241 return NULL; 242 legacy_info->len = sizeof(*legacy_info) + 243 num_fences * sizeof(struct sync_pt_info); 244 strlcpy(legacy_info->name, info->name, sizeof(legacy_info->name)); 245 legacy_info->status = info->status; 246 247 legacy_pt_info = (struct sync_pt_info *)legacy_info->pt_info; 248 for (uint32_t i = 0; i < num_fences; i++) { 249 legacy_pt_info[i].len = sizeof(*legacy_pt_info); 250 strlcpy(legacy_pt_info[i].obj_name, fence_info[i].obj_name, 251 sizeof(legacy_pt_info->obj_name)); 252 strlcpy(legacy_pt_info[i].driver_name, fence_info[i].driver_name, 253 sizeof(legacy_pt_info->driver_name)); 254 legacy_pt_info[i].status = fence_info[i].status; 255 legacy_pt_info[i].timestamp_ns = fence_info[i].timestamp_ns; 256 } 257 258 return legacy_info; 259 } 260 261 static struct sync_file_info* legacy_fence_info_to_sync_file_info( 262 struct sync_fence_info_data *legacy_info) 263 { 264 struct sync_file_info *info; 265 struct sync_pt_info *pt; 266 struct sync_fence_info *fence; 267 size_t num_fences; 268 int err; 269 270 pt = NULL; 271 num_fences = 0; 272 while ((pt = sync_pt_info(legacy_info, pt)) != NULL) 273 num_fences++; 274 275 info = calloc(1, sizeof(struct sync_file_info) + 276 num_fences * sizeof(struct sync_fence_info)); 277 if (!info) { 278 free(legacy_info); 279 return NULL; 280 } 281 info->sync_fence_info = (__u64)(uintptr_t)(info + 1); 282 283 strlcpy(info->name, legacy_info->name, sizeof(info->name)); 284 info->status = legacy_info->status; 285 info->num_fences = num_fences; 286 287 pt = NULL; 288 fence = sync_get_fence_info(info); 289 while ((pt = sync_pt_info(legacy_info, pt)) != NULL) { 290 strlcpy(fence->obj_name, pt->obj_name, sizeof(fence->obj_name)); 291 strlcpy(fence->driver_name, pt->driver_name, 292 sizeof(fence->driver_name)); 293 fence->status = pt->status; 294 fence->timestamp_ns = pt->timestamp_ns; 295 fence++; 296 } 297 298 return info; 299 } 300 301 struct sync_fence_info_data *sync_fence_info(int fd) 302 { 303 struct sync_fence_info_data *legacy_info; 304 int uapi; 305 306 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire); 307 308 if (uapi == UAPI_LEGACY || uapi == UAPI_UNKNOWN) { 309 legacy_info = legacy_sync_fence_info(fd); 310 if (legacy_info || errno != ENOTTY) { 311 if (legacy_info && uapi == UAPI_UNKNOWN) { 312 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY, 313 memory_order_release); 314 } 315 return legacy_info; 316 } 317 } 318 319 struct sync_file_info* file_info; 320 file_info = modern_sync_file_info(fd); 321 if (!file_info) 322 return NULL; 323 if (uapi == UAPI_UNKNOWN) { 324 atomic_store_explicit(&g_uapi_version, UAPI_MODERN, 325 memory_order_release); 326 } 327 legacy_info = sync_file_info_to_legacy_fence_info(file_info); 328 sync_file_info_free(file_info); 329 return legacy_info; 330 } 331 332 struct sync_file_info* sync_file_info(int32_t fd) 333 { 334 struct sync_file_info *info; 335 int uapi; 336 337 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire); 338 339 if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) { 340 info = modern_sync_file_info(fd); 341 if (info || errno != ENOTTY) { 342 if (info && uapi == UAPI_UNKNOWN) { 343 atomic_store_explicit(&g_uapi_version, UAPI_MODERN, 344 memory_order_release); 345 } 346 return info; 347 } 348 } 349 350 struct sync_fence_info_data *legacy_info; 351 legacy_info = legacy_sync_fence_info(fd); 352 if (!legacy_info) 353 return NULL; 354 if (uapi == UAPI_UNKNOWN) { 355 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY, 356 memory_order_release); 357 } 358 info = legacy_fence_info_to_sync_file_info(legacy_info); 359 sync_fence_info_free(legacy_info); 360 return info; 361 } 362 363 struct sync_pt_info *sync_pt_info(struct sync_fence_info_data *info, 364 struct sync_pt_info *itr) 365 { 366 if (itr == NULL) 367 itr = (struct sync_pt_info *) info->pt_info; 368 else 369 itr = (struct sync_pt_info *) ((__u8 *)itr + itr->len); 370 371 if ((__u8 *)itr - (__u8 *)info >= (int)info->len) 372 return NULL; 373 374 return itr; 375 } 376 377 void sync_fence_info_free(struct sync_fence_info_data *info) 378 { 379 free(info); 380 } 381 382 void sync_file_info_free(struct sync_file_info *info) 383 { 384 free(info); 385 } 386 387 388 int sw_sync_timeline_create(void) 389 { 390 int ret; 391 392 ret = open("/sys/kernel/debug/sync/sw_sync", O_RDWR); 393 if (ret < 0) 394 ret = open("/dev/sw_sync", O_RDWR); 395 396 return ret; 397 } 398 399 int sw_sync_timeline_inc(int fd, unsigned count) 400 { 401 __u32 arg = count; 402 403 return ioctl(fd, SW_SYNC_IOC_INC, &arg); 404 } 405 406 int sw_sync_fence_create(int fd, const char *name, unsigned value) 407 { 408 struct sw_sync_create_fence_data data; 409 int err; 410 411 data.value = value; 412 strlcpy(data.name, name, sizeof(data.name)); 413 414 err = ioctl(fd, SW_SYNC_IOC_CREATE_FENCE, &data); 415 if (err < 0) 416 return err; 417 418 return data.fence; 419 } 420
