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
sync_wait(int fd,int timeout)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
legacy_sync_merge(const char * name,int fd1,int fd2)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
modern_sync_merge(const char * name,int fd1,int fd2)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
sync_merge(const char * name,int fd1,int fd2)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
legacy_sync_fence_info(int fd)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
modern_sync_file_info(int fd)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
sync_file_info_to_legacy_fence_info(const struct sync_file_info * info)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
legacy_fence_info_to_sync_file_info(struct sync_fence_info_data * legacy_info)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
sync_fence_info(int fd)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
sync_file_info(int32_t fd)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
sync_pt_info(struct sync_fence_info_data * info,struct sync_pt_info * itr)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
sync_fence_info_free(struct sync_fence_info_data * info)379 void sync_fence_info_free(struct sync_fence_info_data *info)
380 {
381 free(info);
382 }
383
sync_file_info_free(struct sync_file_info * info)384 void sync_file_info_free(struct sync_file_info *info)
385 {
386 free(info);
387 }
388
389
sw_sync_timeline_create(void)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
sw_sync_timeline_inc(int fd,unsigned count)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
sw_sync_fence_create(int fd,const char * name,unsigned value)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