1 /* 2 * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved. 3 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * * Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * * Redistributions in binary form must reproduce the above 10 * copyright notice, this list of conditions and the following 11 * disclaimer in the documentation and/or other materials provided 12 * with the distribution. 13 * * Neither the name of The Linux Foundation nor the names of its 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 24 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 26 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN 27 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <cutils/log.h> 31 #include <cutils/native_handle.h> 32 #include <gralloc_priv.h> 33 #ifdef USE_GENLOCK 34 #include <linux/genlock.h> 35 #endif 36 #include <fcntl.h> 37 #include <sys/ioctl.h> 38 39 #include "genlock.h" 40 41 #define GENLOCK_DEVICE "/dev/genlock" 42 43 namespace { 44 /* Internal function to map the userspace locks to the kernel lock types */ 45 int get_kernel_lock_type(genlock_lock_type lockType) 46 { 47 int kLockType = 0; 48 #ifdef USE_GENLOCK 49 // If the user sets both a read and write lock, higher preference is 50 // given to the write lock. 51 if (lockType & GENLOCK_WRITE_LOCK) { 52 kLockType = GENLOCK_WRLOCK; 53 } else if (lockType & GENLOCK_READ_LOCK) { 54 kLockType = GENLOCK_RDLOCK; 55 } else { 56 ALOGE("%s: invalid lockType (lockType = %d)", 57 __FUNCTION__, lockType); 58 return -1; 59 } 60 #endif 61 return kLockType; 62 } 63 64 /* Internal function to perform the actual lock/unlock operations */ 65 genlock_status_t perform_lock_unlock_operation(native_handle_t *buffer_handle, 66 int lockType, int timeout, 67 int flags) 68 { 69 #ifdef USE_GENLOCK 70 if (private_handle_t::validate(buffer_handle)) { 71 ALOGE("%s: handle is invalid", __FUNCTION__); 72 return GENLOCK_FAILURE; 73 } 74 75 private_handle_t *hnd = reinterpret_cast<private_handle_t*> 76 (buffer_handle); 77 if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) { 78 if (hnd->genlockPrivFd < 0) { 79 ALOGE("%s: the lock has not been created," 80 "or has not been attached", __FUNCTION__); 81 return GENLOCK_FAILURE; 82 } 83 84 genlock_lock lock; 85 lock.op = lockType; 86 lock.flags = flags; 87 lock.timeout = timeout; 88 lock.fd = hnd->genlockHandle; 89 90 #ifdef GENLOCK_IOC_DREADLOCK 91 if (ioctl(hnd->genlockPrivFd, GENLOCK_IOC_DREADLOCK, &lock)) { 92 ALOGE("%s: GENLOCK_IOC_DREADLOCK failed (lockType0x%x," 93 "err=%s fd=%d)", __FUNCTION__, 94 lockType, strerror(errno), hnd->fd); 95 if (ETIMEDOUT == errno) 96 return GENLOCK_TIMEDOUT; 97 98 return GENLOCK_FAILURE; 99 } 100 #else 101 // depreciated 102 if (ioctl(hnd->genlockPrivFd, GENLOCK_IOC_LOCK, &lock)) { 103 ALOGE("%s: GENLOCK_IOC_LOCK failed (lockType0x%x, err=%s fd=%d)" 104 ,__FUNCTION__, lockType, strerror(errno), hnd->fd); 105 if (ETIMEDOUT == errno) 106 return GENLOCK_TIMEDOUT; 107 108 return GENLOCK_FAILURE; 109 } 110 #endif 111 } 112 #endif 113 return GENLOCK_NO_ERROR; 114 } 115 116 /* Internal function to close the fd and release the handle */ 117 void close_genlock_fd_and_handle(int& fd, int& handle) 118 { 119 if (fd >=0 ) { 120 close(fd); 121 fd = -1; 122 } 123 124 if (handle >= 0) { 125 close(handle); 126 handle = -1; 127 } 128 } 129 } 130 /* 131 * Create a genlock lock. The genlock lock file descriptor and the lock 132 * handle are stored in the buffer_handle. 133 * 134 * @param: handle of the buffer 135 * @return error status. 136 */ 137 genlock_status_t genlock_create_lock(native_handle_t *buffer_handle) 138 { 139 genlock_status_t ret = GENLOCK_NO_ERROR; 140 #ifdef USE_GENLOCK 141 if (private_handle_t::validate(buffer_handle)) { 142 ALOGE("%s: handle is invalid", __FUNCTION__); 143 return GENLOCK_FAILURE; 144 } 145 146 private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle); 147 if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) { 148 // Open the genlock device 149 int fd = open(GENLOCK_DEVICE, O_RDWR); 150 if (fd < 0) { 151 ALOGE("%s: open genlock device failed (err=%s)", __FUNCTION__, 152 strerror(errno)); 153 return GENLOCK_FAILURE; 154 } 155 156 // Create a new lock 157 genlock_lock lock; 158 if (ioctl(fd, GENLOCK_IOC_NEW, NULL)) { 159 ALOGE("%s: GENLOCK_IOC_NEW failed (error=%s)", __FUNCTION__, 160 strerror(errno)); 161 close_genlock_fd_and_handle(fd, lock.fd); 162 ret = GENLOCK_FAILURE; 163 } 164 165 // Export the lock for other processes to be able to use it. 166 if (GENLOCK_FAILURE != ret) { 167 if (ioctl(fd, GENLOCK_IOC_EXPORT, &lock)) { 168 ALOGE("%s: GENLOCK_IOC_EXPORT failed (error=%s)", __FUNCTION__, 169 strerror(errno)); 170 close_genlock_fd_and_handle(fd, lock.fd); 171 ret = GENLOCK_FAILURE; 172 } 173 } 174 175 // Store the lock params in the handle. 176 hnd->genlockPrivFd = fd; 177 hnd->genlockHandle = lock.fd; 178 } else { 179 hnd->genlockHandle = 0; 180 } 181 #endif 182 return ret; 183 } 184 185 186 /* 187 * Release a genlock lock associated with the handle. 188 * 189 * @param: handle of the buffer 190 * @return error status. 191 */ 192 genlock_status_t genlock_release_lock(native_handle_t *buffer_handle) 193 { 194 genlock_status_t ret = GENLOCK_NO_ERROR; 195 #ifdef USE_GENLOCK 196 if (private_handle_t::validate(buffer_handle)) { 197 ALOGE("%s: handle is invalid", __FUNCTION__); 198 return GENLOCK_FAILURE; 199 } 200 201 private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle); 202 if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) { 203 if (hnd->genlockPrivFd < 0) { 204 ALOGE("%s: the lock is invalid", __FUNCTION__); 205 return GENLOCK_FAILURE; 206 } 207 208 // Close the fd and reset the parameters. 209 close_genlock_fd_and_handle(hnd->genlockPrivFd, hnd->genlockHandle); 210 } 211 #endif 212 return ret; 213 } 214 215 216 /* 217 * Attach a lock to the buffer handle passed via an IPC. 218 * 219 * @param: handle of the buffer 220 * @return error status. 221 */ 222 genlock_status_t genlock_attach_lock(native_handle_t *buffer_handle) 223 { 224 genlock_status_t ret = GENLOCK_NO_ERROR; 225 #ifdef USE_GENLOCK 226 if (private_handle_t::validate(buffer_handle)) { 227 ALOGE("%s: handle is invalid", __FUNCTION__); 228 return GENLOCK_FAILURE; 229 } 230 231 private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle); 232 if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) { 233 // Open the genlock device 234 int fd = open(GENLOCK_DEVICE, O_RDWR); 235 if (fd < 0) { 236 ALOGE("%s: open genlock device failed (err=%s)", __FUNCTION__, 237 strerror(errno)); 238 return GENLOCK_FAILURE; 239 } 240 241 // Attach the local handle to an existing lock 242 genlock_lock lock; 243 lock.fd = hnd->genlockHandle; 244 if (ioctl(fd, GENLOCK_IOC_ATTACH, &lock)) { 245 ALOGE("%s: GENLOCK_IOC_ATTACH failed (err=%s)", __FUNCTION__, 246 strerror(errno)); 247 close_genlock_fd_and_handle(fd, lock.fd); 248 ret = GENLOCK_FAILURE; 249 } 250 251 // Store the relavant information in the handle 252 hnd->genlockPrivFd = fd; 253 } 254 #endif 255 return ret; 256 } 257 258 /* 259 * Lock the buffer specified by the buffer handle. The lock held by the buffer 260 * is specified by the lockType. This function will block if a write lock is 261 * requested on the buffer which has previously been locked for a read or write 262 * operation. A buffer can be locked by multiple clients for read. An optional 263 * timeout value can be specified. By default, there is no timeout. 264 * 265 * @param: handle of the buffer 266 * @param: type of lock to be acquired by the buffer. 267 * @param: timeout value in ms. GENLOCK_MAX_TIMEOUT is the maximum timeout value. 268 * @return error status. 269 */ 270 genlock_status_t genlock_lock_buffer(native_handle_t *buffer_handle, 271 genlock_lock_type_t lockType, 272 int timeout) 273 { 274 genlock_status_t ret = GENLOCK_NO_ERROR; 275 #ifdef USE_GENLOCK 276 // Translate the locktype 277 int kLockType = get_kernel_lock_type(lockType); 278 if (-1 == kLockType) { 279 ALOGE("%s: invalid lockType", __FUNCTION__); 280 return GENLOCK_FAILURE; 281 } 282 283 if (0 == timeout) { 284 ALOGW("%s: trying to lock a buffer with timeout = 0", __FUNCTION__); 285 } 286 // Call the private function to perform the lock operation specified. 287 ret = perform_lock_unlock_operation(buffer_handle, kLockType, timeout, 0); 288 #endif 289 return ret; 290 } 291 292 293 /* 294 * Unlocks a buffer that has previously been locked by the client. 295 * 296 * @param: handle of the buffer to be unlocked. 297 * @return: error status. 298 */ 299 genlock_status_t genlock_unlock_buffer(native_handle_t *buffer_handle) 300 { 301 genlock_status_t ret = GENLOCK_NO_ERROR; 302 #ifdef USE_GENLOCK 303 // Do the unlock operation by setting the unlock flag. Timeout is always 304 // 0 in this case. 305 ret = perform_lock_unlock_operation(buffer_handle, GENLOCK_UNLOCK, 0, 0); 306 #endif 307 return ret; 308 } 309 310 /* 311 * Blocks the calling process until the lock held on the handle is unlocked. 312 * 313 * @param: handle of the buffer 314 * @param: timeout value for the wait. 315 * return: error status. 316 */ 317 genlock_status_t genlock_wait(native_handle_t *buffer_handle, int timeout) { 318 #ifdef USE_GENLOCK 319 if (private_handle_t::validate(buffer_handle)) { 320 ALOGE("%s: handle is invalid", __FUNCTION__); 321 return GENLOCK_FAILURE; 322 } 323 324 private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle); 325 if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) { 326 if (hnd->genlockPrivFd < 0) { 327 ALOGE("%s: the lock is invalid", __FUNCTION__); 328 return GENLOCK_FAILURE; 329 } 330 331 if (0 == timeout) 332 ALOGW("%s: timeout = 0", __FUNCTION__); 333 334 genlock_lock lock; 335 lock.fd = hnd->genlockHandle; 336 lock.timeout = timeout; 337 if (ioctl(hnd->genlockPrivFd, GENLOCK_IOC_WAIT, &lock)) { 338 ALOGE("%s: GENLOCK_IOC_WAIT failed (err=%s)", __FUNCTION__, 339 strerror(errno)); 340 return GENLOCK_FAILURE; 341 } 342 } 343 #endif 344 return GENLOCK_NO_ERROR; 345 } 346 347 /* 348 * Convert a write lock that we own to a read lock 349 * 350 * @param: handle of the buffer 351 * @param: timeout value for the wait. 352 * return: error status. 353 */ 354 genlock_status_t genlock_write_to_read(native_handle_t *buffer_handle, 355 int timeout) { 356 genlock_status_t ret = GENLOCK_NO_ERROR; 357 #ifdef USE_GENLOCK 358 if (0 == timeout) { 359 ALOGW("%s: trying to lock a buffer with timeout = 0", __FUNCTION__); 360 } 361 // Call the private function to perform the lock operation specified. 362 #ifdef GENLOCK_IOC_DREADLOCK 363 ret = perform_lock_unlock_operation(buffer_handle, GENLOCK_RDLOCK, timeout, 364 GENLOCK_WRITE_TO_READ); 365 #else 366 // depreciated 367 ret = perform_lock_unlock_operation(buffer_handle, GENLOCK_RDLOCK, 368 timeout, 0); 369 #endif 370 #endif 371 return ret; 372 } 373
