1 /*
2 * sync abstraction
3 * Copyright 2015-2016 Collabora Ltd.
4 *
5 * Based on the implementation from the Android Open Source Project,
6 *
7 * Copyright 2012 Google, Inc
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
23 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
24 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
26 */
27
28 #ifndef _LIBSYNC_H
29 #define _LIBSYNC_H
30
31 #include <assert.h>
32 #include <errno.h>
33 #include <poll.h>
34 #include <stdbool.h>
35 #include <stdint.h>
36 #include <string.h>
37 #include <sys/ioctl.h>
38 #include <unistd.h>
39 #include <stdlib.h>
40 #include <time.h>
41
42 #include "util/detect_os.h"
43
44 #if defined(__cplusplus)
45 extern "C" {
46 #endif
47
48 #if DETECT_OS_ANDROID
49 /* On Android, rely on the system's libsync instead of rolling our own
50 * sync_wait() and sync_merge(). This gives us compatibility with pre-4.7
51 * Android kernels.
52 */
53 #include <android/sync.h>
54
55 /**
56 * Check if the fd represents a valid fence-fd.
57 *
58 * The android variant of this debug helper is implemented on top of the
59 * system's libsync for compatibility with pre-4.7 android kernels.
60 */
61 static inline bool
sync_valid_fd(int fd)62 sync_valid_fd(int fd)
63 {
64 /* sync_file_info() only available in SDK 26. */
65 #if ANDROID_API_LEVEL >= 26
66 struct sync_file_info *info = sync_file_info(fd);
67 if (!info)
68 return false;
69 sync_file_info_free(info);
70 #endif
71 return true;
72 }
73 #else
74
75 #ifndef SYNC_IOC_MERGE
76 /* duplicated from linux/sync_file.h to avoid build-time dependency
77 * on new (v4.7) kernel headers. Once distro's are mostly using
78 * something newer than v4.7 drop this and #include <linux/sync_file.h>
79 * instead.
80 */
81 struct sync_merge_data {
82 char name[32];
83 int32_t fd2;
84 int32_t fence;
85 uint32_t flags;
86 uint32_t pad;
87 };
88
89 struct sync_fence_info {
90 char obj_name[32];
91 char driver_name[32];
92 int32_t status;
93 uint32_t flags;
94 uint64_t timestamp_ns;
95 };
96
97 struct sync_file_info {
98 char name[32];
99 int32_t status;
100 uint32_t flags;
101 uint32_t num_fences;
102 uint32_t pad;
103
104 uint64_t sync_fence_info;
105 };
106
107 #define SYNC_IOC_MAGIC '>'
108 #define SYNC_IOC_MERGE _IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
109 #define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info)
110 #endif
111
112
113 static inline int sync_wait(int fd, int timeout)
114 {
115 struct pollfd fds = {0};
116 int ret;
117 struct timespec poll_start, poll_end;
118
119 fds.fd = fd;
120 fds.events = POLLIN;
121
122 do {
123 clock_gettime(CLOCK_MONOTONIC, &poll_start);
124 ret = poll(&fds, 1, timeout);
125 clock_gettime(CLOCK_MONOTONIC, &poll_end);
126 if (ret > 0) {
127 if (fds.revents & (POLLERR | POLLNVAL)) {
128 errno = EINVAL;
129 return -1;
130 }
131 return 0;
132 } else if (ret == 0) {
133 errno = ETIME;
134 return -1;
135 }
136 timeout -= (poll_end.tv_sec - poll_start.tv_sec) * 1000 +
137 (poll_end.tv_nsec - poll_end.tv_nsec) / 1000000;
138 } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
139
140 return ret;
141 }
142
143 static inline int sync_merge(const char *name, int fd1, int fd2)
144 {
145 struct sync_merge_data data = {{0}};
146 int ret;
147
148 data.fd2 = fd2;
149 strncpy(data.name, name, sizeof(data.name));
150
151 do {
152 ret = ioctl(fd1, SYNC_IOC_MERGE, &data);
153 } while (ret == -1 && (errno == EINTR || errno == EAGAIN));
154
155 if (ret < 0)
156 return ret;
157
158 return data.fence;
159 }
160
161 /**
162 * Check if the fd represents a valid fence-fd.
163 */
164 static inline bool
165 sync_valid_fd(int fd)
166 {
167 struct sync_file_info info = {{0}};
168 return ioctl(fd, SYNC_IOC_FILE_INFO, &info) >= 0;
169 }
170
171 static inline struct sync_file_info* sync_file_info(int32_t fd)
172 {
173 struct sync_file_info local_info;
174 struct sync_file_info *info;
175 int err;
176
177 memset(&local_info, 0, sizeof(local_info));
178 err = ioctl(fd, SYNC_IOC_FILE_INFO, &local_info);
179 if (err < 0)
180 return NULL;
181
182 info = (struct sync_file_info *)calloc(1, sizeof(struct sync_file_info) +
183 local_info.num_fences * sizeof(struct sync_fence_info));
184 if (!info)
185 return NULL;
186
187 info->num_fences = local_info.num_fences;
188 info->sync_fence_info = (uint64_t)(uintptr_t)(info + 1);
189
190 err = ioctl(fd, SYNC_IOC_FILE_INFO, info);
191 if (err < 0) {
192 free(info);
193 return NULL;
194 }
195
196 return info;
197 }
198
199 #endif /* DETECT_OS_ANDROID */
200
201 /* accumulate fd2 into fd1. If *fd1 is not a valid fd then dup fd2,
202 * otherwise sync_merge() and close the old *fd1. This can be used
203 * to implement the pattern:
204 *
205 * init()
206 * {
207 * batch.fence_fd = -1;
208 * }
209 *
210 * // does *NOT* take ownership of fd
211 * server_sync(int fd)
212 * {
213 * if (sync_accumulate("foo", &batch.fence_fd, fd)) {
214 * ... error ...
215 * }
216 * }
217 */
sync_accumulate(const char * name,int * fd1,int fd2)218 static inline int sync_accumulate(const char *name, int *fd1, int fd2)
219 {
220 int ret;
221
222 assert(fd2 >= 0);
223
224 if (*fd1 < 0) {
225 *fd1 = dup(fd2);
226 return 0;
227 }
228
229 ret = sync_merge(name, *fd1, fd2);
230 if (ret < 0) {
231 /* leave *fd1 as it is */
232 return ret;
233 }
234
235 close(*fd1);
236 *fd1 = ret;
237
238 return 0;
239 }
240
241 /* Helper macro to complain if fd is non-negative and not a valid fence fd.
242 * Sprinkle this around to help catch fd lifetime issues.
243 */
244 #if MESA_DEBUG
245 # include "util/log.h"
246 # define validate_fence_fd(fd) do { \
247 if (((fd) >= 0) && !sync_valid_fd(fd)) \
248 mesa_loge("%s:%d: invalid fence fd: %d", __func__, __LINE__, (fd)); \
249 } while (0)
250 #else
251 # define validate_fence_fd(fd) do {} while (0)
252 #endif
253
254 #if defined(__cplusplus)
255 }
256 #endif
257
258 #endif
259