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 /* Prototypes for deprecated functions that used to be declared in the legacy
34 * android/sync.h. They've been moved here to make sure new code does not use
35 * them, but the functions are still defined to avoid breaking existing
36 * binaries. Eventually they can be removed altogether.
37 */
38 struct sync_fence_info_data {
39 uint32_t len;
40 char name[32];
41 int32_t status;
42 uint8_t pt_info[0];
43 };
44 struct sync_pt_info {
45 uint32_t len;
46 char obj_name[32];
47 char driver_name[32];
48 int32_t status;
49 uint64_t timestamp_ns;
50 uint8_t driver_data[0];
51 };
52 struct sync_fence_info_data* sync_fence_info(int fd);
53 struct sync_pt_info* sync_pt_info(struct sync_fence_info_data* info, struct sync_pt_info* itr);
54 void sync_fence_info_free(struct sync_fence_info_data* info);
55
56 /* Legacy Sync API */
57
58 struct sync_legacy_merge_data {
59 int32_t fd2;
60 char name[32];
61 int32_t fence;
62 };
63
64 /**
65 * DOC: SYNC_IOC_MERGE - merge two fences
66 *
67 * Takes a struct sync_merge_data. Creates a new fence containing copies of
68 * the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the
69 * new fence's fd in sync_merge_data.fence
70 *
71 * This is the legacy version of the Sync API before the de-stage that happened
72 * on Linux kernel 4.7.
73 */
74 #define SYNC_IOC_LEGACY_MERGE _IOWR(SYNC_IOC_MAGIC, 1, \
75 struct sync_legacy_merge_data)
76
77 /**
78 * DOC: SYNC_IOC_LEGACY_FENCE_INFO - get detailed information on a fence
79 *
80 * Takes a struct sync_fence_info_data with extra space allocated for pt_info.
81 * Caller should write the size of the buffer into len. On return, len is
82 * updated to reflect the total size of the sync_fence_info_data including
83 * pt_info.
84 *
85 * pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence.
86 * To iterate over the sync_pt_infos, use the sync_pt_info.len field.
87 *
88 * This is the legacy version of the Sync API before the de-stage that happened
89 * on Linux kernel 4.7.
90 */
91 #define SYNC_IOC_LEGACY_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2,\
92 struct sync_fence_info_data)
93
94 /* SW Sync API */
95
96 struct sw_sync_create_fence_data {
97 __u32 value;
98 char name[32];
99 __s32 fence;
100 };
101
102 #define SW_SYNC_IOC_MAGIC 'W'
103 #define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0, struct sw_sync_create_fence_data)
104 #define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
105
106 // ---------------------------------------------------------------------------
107 // Support for caching the sync uapi version.
108 //
109 // This library supports both legacy (android/staging) uapi and modern
110 // (mainline) sync uapi. Library calls first try one uapi, and if that fails,
111 // try the other. Since any given kernel only supports one uapi version, after
112 // the first successful syscall we know what the kernel supports and can skip
113 // trying the other.
114
115 enum uapi_version {
116 UAPI_UNKNOWN,
117 UAPI_MODERN,
118 UAPI_LEGACY
119 };
120 static atomic_int g_uapi_version = ATOMIC_VAR_INIT(UAPI_UNKNOWN);
121
122 // ---------------------------------------------------------------------------
123
sync_wait(int fd,int timeout)124 int sync_wait(int fd, int timeout)
125 {
126 struct pollfd fds;
127 int ret;
128
129 if (fd < 0) {
130 errno = EINVAL;
131 return -1;
132 }
133
134 fds.fd = fd;
135 fds.events = POLLIN;
136
137 do {
138 ret = poll(&fds, 1, timeout);
139 if (ret > 0) {
140 if (fds.revents & (POLLERR | POLLNVAL)) {
141 errno = EINVAL;
142 return -1;
143 }
144 return 0;
145 } else if (ret == 0) {
146 errno = ETIME;
147 return -1;
148 }
149 } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
150
151 return ret;
152 }
153
legacy_sync_merge(const char * name,int fd1,int fd2)154 static int legacy_sync_merge(const char *name, int fd1, int fd2)
155 {
156 struct sync_legacy_merge_data data;
157 int ret;
158
159 data.fd2 = fd2;
160 strlcpy(data.name, name, sizeof(data.name));
161 ret = ioctl(fd1, SYNC_IOC_LEGACY_MERGE, &data);
162 if (ret < 0)
163 return ret;
164 return data.fence;
165 }
166
modern_sync_merge(const char * name,int fd1,int fd2)167 static int modern_sync_merge(const char *name, int fd1, int fd2)
168 {
169 struct sync_merge_data data;
170 int ret;
171
172 data.fd2 = fd2;
173 strlcpy(data.name, name, sizeof(data.name));
174 data.flags = 0;
175 data.pad = 0;
176
177 ret = ioctl(fd1, SYNC_IOC_MERGE, &data);
178 if (ret < 0)
179 return ret;
180 return data.fence;
181 }
182
sync_merge(const char * name,int fd1,int fd2)183 int sync_merge(const char *name, int fd1, int fd2)
184 {
185 int uapi;
186 int ret;
187
188 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire);
189
190 if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) {
191 ret = modern_sync_merge(name, fd1, fd2);
192 if (ret >= 0 || errno != ENOTTY) {
193 if (ret >= 0 && uapi == UAPI_UNKNOWN) {
194 atomic_store_explicit(&g_uapi_version, UAPI_MODERN,
195 memory_order_release);
196 }
197 return ret;
198 }
199 }
200
201 ret = legacy_sync_merge(name, fd1, fd2);
202 if (ret >= 0 && uapi == UAPI_UNKNOWN) {
203 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY,
204 memory_order_release);
205 }
206 return ret;
207 }
208
legacy_sync_fence_info(int fd)209 static struct sync_fence_info_data *legacy_sync_fence_info(int fd)
210 {
211 struct sync_fence_info_data *legacy_info;
212 struct sync_pt_info *legacy_pt_info;
213 int err;
214
215 legacy_info = malloc(4096);
216 if (legacy_info == NULL)
217 return NULL;
218
219 legacy_info->len = 4096;
220 err = ioctl(fd, SYNC_IOC_LEGACY_FENCE_INFO, legacy_info);
221 if (err < 0) {
222 free(legacy_info);
223 return NULL;
224 }
225 return legacy_info;
226 }
227
modern_sync_file_info(int fd)228 static struct sync_file_info *modern_sync_file_info(int fd)
229 {
230 struct sync_file_info local_info;
231 struct sync_file_info *info;
232 int err;
233
234 memset(&local_info, 0, sizeof(local_info));
235 err = ioctl(fd, SYNC_IOC_FILE_INFO, &local_info);
236 if (err < 0)
237 return NULL;
238
239 info = calloc(1, sizeof(struct sync_file_info) +
240 local_info.num_fences * sizeof(struct sync_fence_info));
241 if (!info)
242 return NULL;
243
244 info->num_fences = local_info.num_fences;
245 info->sync_fence_info = (__u64)(uintptr_t)(info + 1);
246
247 err = ioctl(fd, SYNC_IOC_FILE_INFO, info);
248 if (err < 0) {
249 free(info);
250 return NULL;
251 }
252
253 return info;
254 }
255
sync_file_info_to_legacy_fence_info(const struct sync_file_info * info)256 static struct sync_fence_info_data *sync_file_info_to_legacy_fence_info(
257 const struct sync_file_info *info)
258 {
259 struct sync_fence_info_data *legacy_info;
260 struct sync_pt_info *legacy_pt_info;
261 const struct sync_fence_info *fence_info = sync_get_fence_info(info);
262 const uint32_t num_fences = info->num_fences;
263
264 legacy_info = malloc(4096);
265 if (legacy_info == NULL)
266 return NULL;
267 legacy_info->len = sizeof(*legacy_info) +
268 num_fences * sizeof(struct sync_pt_info);
269 strlcpy(legacy_info->name, info->name, sizeof(legacy_info->name));
270 legacy_info->status = info->status;
271
272 legacy_pt_info = (struct sync_pt_info *)legacy_info->pt_info;
273 for (uint32_t i = 0; i < num_fences; i++) {
274 legacy_pt_info[i].len = sizeof(*legacy_pt_info);
275 strlcpy(legacy_pt_info[i].obj_name, fence_info[i].obj_name,
276 sizeof(legacy_pt_info->obj_name));
277 strlcpy(legacy_pt_info[i].driver_name, fence_info[i].driver_name,
278 sizeof(legacy_pt_info->driver_name));
279 legacy_pt_info[i].status = fence_info[i].status;
280 legacy_pt_info[i].timestamp_ns = fence_info[i].timestamp_ns;
281 }
282
283 return legacy_info;
284 }
285
legacy_fence_info_to_sync_file_info(struct sync_fence_info_data * legacy_info)286 static struct sync_file_info* legacy_fence_info_to_sync_file_info(
287 struct sync_fence_info_data *legacy_info)
288 {
289 struct sync_file_info *info;
290 struct sync_pt_info *pt;
291 struct sync_fence_info *fence;
292 size_t num_fences;
293 int err;
294
295 pt = NULL;
296 num_fences = 0;
297 while ((pt = sync_pt_info(legacy_info, pt)) != NULL)
298 num_fences++;
299
300 info = calloc(1, sizeof(struct sync_file_info) +
301 num_fences * sizeof(struct sync_fence_info));
302 if (!info) {
303 return NULL;
304 }
305 info->sync_fence_info = (__u64)(uintptr_t)(info + 1);
306
307 strlcpy(info->name, legacy_info->name, sizeof(info->name));
308 info->status = legacy_info->status;
309 info->num_fences = num_fences;
310
311 pt = NULL;
312 fence = sync_get_fence_info(info);
313 while ((pt = sync_pt_info(legacy_info, pt)) != NULL) {
314 strlcpy(fence->obj_name, pt->obj_name, sizeof(fence->obj_name));
315 strlcpy(fence->driver_name, pt->driver_name,
316 sizeof(fence->driver_name));
317 fence->status = pt->status;
318 fence->timestamp_ns = pt->timestamp_ns;
319 fence++;
320 }
321
322 return info;
323 }
324
sync_fence_info(int fd)325 struct sync_fence_info_data *sync_fence_info(int fd)
326 {
327 struct sync_fence_info_data *legacy_info;
328 int uapi;
329
330 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire);
331
332 if (uapi == UAPI_LEGACY || uapi == UAPI_UNKNOWN) {
333 legacy_info = legacy_sync_fence_info(fd);
334 if (legacy_info || errno != ENOTTY) {
335 if (legacy_info && uapi == UAPI_UNKNOWN) {
336 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY,
337 memory_order_release);
338 }
339 return legacy_info;
340 }
341 }
342
343 struct sync_file_info* file_info;
344 file_info = modern_sync_file_info(fd);
345 if (!file_info)
346 return NULL;
347 if (uapi == UAPI_UNKNOWN) {
348 atomic_store_explicit(&g_uapi_version, UAPI_MODERN,
349 memory_order_release);
350 }
351 legacy_info = sync_file_info_to_legacy_fence_info(file_info);
352 sync_file_info_free(file_info);
353 return legacy_info;
354 }
355
sync_file_info(int32_t fd)356 struct sync_file_info* sync_file_info(int32_t fd)
357 {
358 struct sync_file_info *info;
359 int uapi;
360
361 uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire);
362
363 if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) {
364 info = modern_sync_file_info(fd);
365 if (info || errno != ENOTTY) {
366 if (info && uapi == UAPI_UNKNOWN) {
367 atomic_store_explicit(&g_uapi_version, UAPI_MODERN,
368 memory_order_release);
369 }
370 return info;
371 }
372 }
373
374 struct sync_fence_info_data *legacy_info;
375 legacy_info = legacy_sync_fence_info(fd);
376 if (!legacy_info)
377 return NULL;
378 if (uapi == UAPI_UNKNOWN) {
379 atomic_store_explicit(&g_uapi_version, UAPI_LEGACY,
380 memory_order_release);
381 }
382 info = legacy_fence_info_to_sync_file_info(legacy_info);
383 sync_fence_info_free(legacy_info);
384 return info;
385 }
386
sync_pt_info(struct sync_fence_info_data * info,struct sync_pt_info * itr)387 struct sync_pt_info *sync_pt_info(struct sync_fence_info_data *info,
388 struct sync_pt_info *itr)
389 {
390 if (itr == NULL)
391 itr = (struct sync_pt_info *) info->pt_info;
392 else
393 itr = (struct sync_pt_info *) ((__u8 *)itr + itr->len);
394
395 if ((__u8 *)itr - (__u8 *)info >= (int)info->len)
396 return NULL;
397
398 return itr;
399 }
400
sync_fence_info_free(struct sync_fence_info_data * info)401 void sync_fence_info_free(struct sync_fence_info_data *info)
402 {
403 free(info);
404 }
405
sync_file_info_free(struct sync_file_info * info)406 void sync_file_info_free(struct sync_file_info *info)
407 {
408 free(info);
409 }
410
411
sw_sync_timeline_create(void)412 int sw_sync_timeline_create(void)
413 {
414 int ret;
415
416 ret = open("/sys/kernel/debug/sync/sw_sync", O_RDWR);
417 if (ret < 0)
418 ret = open("/dev/sw_sync", O_RDWR);
419
420 return ret;
421 }
422
sw_sync_timeline_inc(int fd,unsigned count)423 int sw_sync_timeline_inc(int fd, unsigned count)
424 {
425 __u32 arg = count;
426
427 return ioctl(fd, SW_SYNC_IOC_INC, &arg);
428 }
429
sw_sync_fence_create(int fd,const char * name,unsigned value)430 int sw_sync_fence_create(int fd, const char *name, unsigned value)
431 {
432 struct sw_sync_create_fence_data data;
433 int err;
434
435 data.value = value;
436 strlcpy(data.name, name, sizeof(data.name));
437
438 err = ioctl(fd, SW_SYNC_IOC_CREATE_FENCE, &data);
439 if (err < 0)
440 return err;
441
442 return data.fence;
443 }
444