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; 220 221 info->num_fences = local_info.num_fences; 222 info->sync_fence_info = (__u64)(uintptr_t)(info + 1); 223 224 err = ioctl(fd, SYNC_IOC_FILE_INFO, info); 225 if (err < 0) { 226 free(info); 227 return NULL; 228 } 229 230 return info; 231 } 232 233 static struct sync_fence_info_data *sync_file_info_to_legacy_fence_info( 234 const struct sync_file_info *info) 235 { 236 struct sync_fence_info_data *legacy_info; 237 struct sync_pt_info *legacy_pt_info; 238 const struct sync_fence_info *fence_info = sync_get_fence_info(info); 239 const uint32_t num_fences = info->num_fences; 240 241 legacy_info = malloc(4096); 242 if (legacy_info == NULL) 243 return NULL; 244 legacy_info->len = sizeof(*legacy_info) + 245 num_fences * sizeof(struct sync_pt_info); 246 strlcpy(legacy_info->name, info->name, sizeof(legacy_info->name)); 247 legacy_info->status = info->status; 248 249 legacy_pt_info = (struct sync_pt_info *)legacy_info->pt_info; 250 for (uint32_t i = 0; i < num_fences; i++) { 251 legacy_pt_info[i].len = sizeof(*legacy_pt_info); 252 strlcpy(legacy_pt_info[i].obj_name, fence_info[i].obj_name, 253 sizeof(legacy_pt_info->obj_name)); 254 strlcpy(legacy_pt_info[i].driver_name, fence_info[i].driver_name, 255 sizeof(legacy_pt_info->driver_name)); 256 legacy_pt_info[i].status = fence_info[i].status; 257 legacy_pt_info[i].timestamp_ns = fence_info[i].timestamp_ns; 258 } 259 260 return legacy_info; 261 } 262 263 static struct sync_file_info* legacy_fence_info_to_sync_file_info( 264 struct sync_fence_info_data *legacy_info) 265 { 266 struct sync_file_info *info; 267 struct sync_pt_info *pt; 268 struct sync_fence_info *fence; 269 size_t num_fences; 270 int err; 271 272 pt = NULL; 273 num_fences = 0; 274 while ((pt = sync_pt_info(legacy_info, pt)) != NULL) 275 num_fences++; 276 277 info = calloc(1, sizeof(struct sync_file_info) + 278 num_fences * sizeof(struct sync_fence_info)); 279 if (!info) { 280 free(legacy_info); 281 return NULL; 282 } 283 info->sync_fence_info = (__u64)(uintptr_t)(info + 1); 284 285 strlcpy(info->name, legacy_info->name, sizeof(info->name)); 286 info->status = legacy_info->status; 287 info->num_fences = num_fences; 288 289 pt = NULL; 290 fence = sync_get_fence_info(info); 291 while ((pt = sync_pt_info(legacy_info, pt)) != NULL) { 292 strlcpy(fence->obj_name, pt->obj_name, sizeof(fence->obj_name)); 293 strlcpy(fence->driver_name, pt->driver_name, 294 sizeof(fence->driver_name)); 295 fence->status = pt->status; 296 fence->timestamp_ns = pt->timestamp_ns; 297 fence++; 298 } 299 300 return info; 301 } 302 303 struct sync_fence_info_data *sync_fence_info(int fd) 304 { 305 struct sync_fence_info_data *legacy_info; 306 int uapi; 307 308 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire); 309 310 if (uapi == UAPI_LEGACY || uapi == UAPI_UNKNOWN) { 311 legacy_info = legacy_sync_fence_info(fd); 312 if (legacy_info || errno != ENOTTY) { 313 if (legacy_info && uapi == UAPI_UNKNOWN) { 314 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY, 315 memory_order_release); 316 } 317 return legacy_info; 318 } 319 } 320 321 struct sync_file_info* file_info; 322 file_info = modern_sync_file_info(fd); 323 if (!file_info) 324 return NULL; 325 if (uapi == UAPI_UNKNOWN) { 326 atomic_store_explicit(&g_uapi_version, UAPI_MODERN, 327 memory_order_release); 328 } 329 legacy_info = sync_file_info_to_legacy_fence_info(file_info); 330 sync_file_info_free(file_info); 331 return legacy_info; 332 } 333 334 struct sync_file_info* sync_file_info(int32_t fd) 335 { 336 struct sync_file_info *info; 337 int uapi; 338 339 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire); 340 341 if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) { 342 info = modern_sync_file_info(fd); 343 if (info || errno != ENOTTY) { 344 if (info && uapi == UAPI_UNKNOWN) { 345 atomic_store_explicit(&g_uapi_version, UAPI_MODERN, 346 memory_order_release); 347 } 348 return info; 349 } 350 } 351 352 struct sync_fence_info_data *legacy_info; 353 legacy_info = legacy_sync_fence_info(fd); 354 if (!legacy_info) 355 return NULL; 356 if (uapi == UAPI_UNKNOWN) { 357 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY, 358 memory_order_release); 359 } 360 info = legacy_fence_info_to_sync_file_info(legacy_info); 361 sync_fence_info_free(legacy_info); 362 return info; 363 } 364 365 struct sync_pt_info *sync_pt_info(struct sync_fence_info_data *info, 366 struct sync_pt_info *itr) 367 { 368 if (itr == NULL) 369 itr = (struct sync_pt_info *) info->pt_info; 370 else 371 itr = (struct sync_pt_info *) ((__u8 *)itr + itr->len); 372 373 if ((__u8 *)itr - (__u8 *)info >= (int)info->len) 374 return NULL; 375 376 return itr; 377 } 378 379 void sync_fence_info_free(struct sync_fence_info_data *info) 380 { 381 free(info); 382 } 383 384 void sync_file_info_free(struct sync_file_info *info) 385 { 386 free(info); 387 } 388 389 390 int sw_sync_timeline_create(void) 391 { 392 int ret; 393 394 ret = open("/sys/kernel/debug/sync/sw_sync", O_RDWR); 395 if (ret < 0) 396 ret = open("/dev/sw_sync", O_RDWR); 397 398 return ret; 399 } 400 401 int sw_sync_timeline_inc(int fd, unsigned count) 402 { 403 __u32 arg = count; 404 405 return ioctl(fd, SW_SYNC_IOC_INC, &arg); 406 } 407 408 int sw_sync_fence_create(int fd, const char *name, unsigned value) 409 { 410 struct sw_sync_create_fence_data data; 411 int err; 412 413 data.value = value; 414 strlcpy(data.name, name, sizeof(data.name)); 415 416 err = ioctl(fd, SW_SYNC_IOC_CREATE_FENCE, &data); 417 if (err < 0) 418 return err; 419 420 return data.fence; 421 } 422
