/*
* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <cutils/log.h>
#include <cutils/native_handle.h>
#include <gralloc_priv.h>
#ifdef USE_GENLOCK
#include <linux/genlock.h>
#endif
#include <fcntl.h>
#include <sys/ioctl.h>
#include "genlock.h"
#define GENLOCK_DEVICE "/dev/genlock"
namespace {
/* Internal function to map the userspace locks to the kernel lock types */
int get_kernel_lock_type(genlock_lock_type lockType)
{
int kLockType = 0;
#ifdef USE_GENLOCK
// If the user sets both a read and write lock, higher preference is
// given to the write lock.
if (lockType & GENLOCK_WRITE_LOCK) {
kLockType = GENLOCK_WRLOCK;
} else if (lockType & GENLOCK_READ_LOCK) {
kLockType = GENLOCK_RDLOCK;
} else {
ALOGE("%s: invalid lockType (lockType = %d)",
__FUNCTION__, lockType);
return -1;
}
#endif
return kLockType;
}
/* Internal function to perform the actual lock/unlock operations */
genlock_status_t perform_lock_unlock_operation(native_handle_t *buffer_handle,
int lockType, int timeout,
int flags)
{
#ifdef USE_GENLOCK
if (private_handle_t::validate(buffer_handle)) {
ALOGE("%s: handle is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
private_handle_t *hnd = reinterpret_cast<private_handle_t*>
(buffer_handle);
if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) {
if (hnd->genlockPrivFd < 0) {
ALOGE("%s: the lock has not been created,"
"or has not been attached", __FUNCTION__);
return GENLOCK_FAILURE;
}
genlock_lock lock;
lock.op = lockType;
lock.flags = flags;
lock.timeout = timeout;
lock.fd = hnd->genlockHandle;
#ifdef GENLOCK_IOC_DREADLOCK
if (ioctl(hnd->genlockPrivFd, GENLOCK_IOC_DREADLOCK, &lock)) {
ALOGE("%s: GENLOCK_IOC_DREADLOCK failed (lockType0x%x,"
"err=%s fd=%d)", __FUNCTION__,
lockType, strerror(errno), hnd->fd);
if (ETIMEDOUT == errno)
return GENLOCK_TIMEDOUT;
return GENLOCK_FAILURE;
}
#else
// depreciated
if (ioctl(hnd->genlockPrivFd, GENLOCK_IOC_LOCK, &lock)) {
ALOGE("%s: GENLOCK_IOC_LOCK failed (lockType0x%x, err=%s fd=%d)"
,__FUNCTION__, lockType, strerror(errno), hnd->fd);
if (ETIMEDOUT == errno)
return GENLOCK_TIMEDOUT;
return GENLOCK_FAILURE;
}
#endif
}
#endif
return GENLOCK_NO_ERROR;
}
/* Internal function to close the fd and release the handle */
void close_genlock_fd_and_handle(int& fd, int& handle)
{
if (fd >=0 ) {
close(fd);
fd = -1;
}
if (handle >= 0) {
close(handle);
handle = -1;
}
}
}
/*
* Create a genlock lock. The genlock lock file descriptor and the lock
* handle are stored in the buffer_handle.
*
* @param: handle of the buffer
* @return error status.
*/
genlock_status_t genlock_create_lock(native_handle_t *buffer_handle)
{
genlock_status_t ret = GENLOCK_NO_ERROR;
#ifdef USE_GENLOCK
if (private_handle_t::validate(buffer_handle)) {
ALOGE("%s: handle is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle);
if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) {
// Open the genlock device
int fd = open(GENLOCK_DEVICE, O_RDWR);
if (fd < 0) {
ALOGE("%s: open genlock device failed (err=%s)", __FUNCTION__,
strerror(errno));
return GENLOCK_FAILURE;
}
// Create a new lock
genlock_lock lock;
if (ioctl(fd, GENLOCK_IOC_NEW, NULL)) {
ALOGE("%s: GENLOCK_IOC_NEW failed (error=%s)", __FUNCTION__,
strerror(errno));
close_genlock_fd_and_handle(fd, lock.fd);
ret = GENLOCK_FAILURE;
}
// Export the lock for other processes to be able to use it.
if (GENLOCK_FAILURE != ret) {
if (ioctl(fd, GENLOCK_IOC_EXPORT, &lock)) {
ALOGE("%s: GENLOCK_IOC_EXPORT failed (error=%s)", __FUNCTION__,
strerror(errno));
close_genlock_fd_and_handle(fd, lock.fd);
ret = GENLOCK_FAILURE;
}
}
// Store the lock params in the handle.
hnd->genlockPrivFd = fd;
hnd->genlockHandle = lock.fd;
} else {
hnd->genlockHandle = 0;
}
#endif
return ret;
}
/*
* Release a genlock lock associated with the handle.
*
* @param: handle of the buffer
* @return error status.
*/
genlock_status_t genlock_release_lock(native_handle_t *buffer_handle)
{
genlock_status_t ret = GENLOCK_NO_ERROR;
#ifdef USE_GENLOCK
if (private_handle_t::validate(buffer_handle)) {
ALOGE("%s: handle is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle);
if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) {
if (hnd->genlockPrivFd < 0) {
ALOGE("%s: the lock is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
// Close the fd and reset the parameters.
close_genlock_fd_and_handle(hnd->genlockPrivFd, hnd->genlockHandle);
}
#endif
return ret;
}
/*
* Attach a lock to the buffer handle passed via an IPC.
*
* @param: handle of the buffer
* @return error status.
*/
genlock_status_t genlock_attach_lock(native_handle_t *buffer_handle)
{
genlock_status_t ret = GENLOCK_NO_ERROR;
#ifdef USE_GENLOCK
if (private_handle_t::validate(buffer_handle)) {
ALOGE("%s: handle is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle);
if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) {
// Open the genlock device
int fd = open(GENLOCK_DEVICE, O_RDWR);
if (fd < 0) {
ALOGE("%s: open genlock device failed (err=%s)", __FUNCTION__,
strerror(errno));
return GENLOCK_FAILURE;
}
// Attach the local handle to an existing lock
genlock_lock lock;
lock.fd = hnd->genlockHandle;
if (ioctl(fd, GENLOCK_IOC_ATTACH, &lock)) {
ALOGE("%s: GENLOCK_IOC_ATTACH failed (err=%s)", __FUNCTION__,
strerror(errno));
close_genlock_fd_and_handle(fd, lock.fd);
ret = GENLOCK_FAILURE;
}
// Store the relavant information in the handle
hnd->genlockPrivFd = fd;
}
#endif
return ret;
}
/*
* Lock the buffer specified by the buffer handle. The lock held by the buffer
* is specified by the lockType. This function will block if a write lock is
* requested on the buffer which has previously been locked for a read or write
* operation. A buffer can be locked by multiple clients for read. An optional
* timeout value can be specified. By default, there is no timeout.
*
* @param: handle of the buffer
* @param: type of lock to be acquired by the buffer.
* @param: timeout value in ms. GENLOCK_MAX_TIMEOUT is the maximum timeout value.
* @return error status.
*/
genlock_status_t genlock_lock_buffer(native_handle_t *buffer_handle,
genlock_lock_type_t lockType,
int timeout)
{
genlock_status_t ret = GENLOCK_NO_ERROR;
#ifdef USE_GENLOCK
// Translate the locktype
int kLockType = get_kernel_lock_type(lockType);
if (-1 == kLockType) {
ALOGE("%s: invalid lockType", __FUNCTION__);
return GENLOCK_FAILURE;
}
if (0 == timeout) {
ALOGW("%s: trying to lock a buffer with timeout = 0", __FUNCTION__);
}
// Call the private function to perform the lock operation specified.
ret = perform_lock_unlock_operation(buffer_handle, kLockType, timeout, 0);
#endif
return ret;
}
/*
* Unlocks a buffer that has previously been locked by the client.
*
* @param: handle of the buffer to be unlocked.
* @return: error status.
*/
genlock_status_t genlock_unlock_buffer(native_handle_t *buffer_handle)
{
genlock_status_t ret = GENLOCK_NO_ERROR;
#ifdef USE_GENLOCK
// Do the unlock operation by setting the unlock flag. Timeout is always
// 0 in this case.
ret = perform_lock_unlock_operation(buffer_handle, GENLOCK_UNLOCK, 0, 0);
#endif
return ret;
}
/*
* Blocks the calling process until the lock held on the handle is unlocked.
*
* @param: handle of the buffer
* @param: timeout value for the wait.
* return: error status.
*/
genlock_status_t genlock_wait(native_handle_t *buffer_handle, int timeout) {
#ifdef USE_GENLOCK
if (private_handle_t::validate(buffer_handle)) {
ALOGE("%s: handle is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
private_handle_t *hnd = reinterpret_cast<private_handle_t*>(buffer_handle);
if ((hnd->flags & private_handle_t::PRIV_FLAGS_UNSYNCHRONIZED) == 0) {
if (hnd->genlockPrivFd < 0) {
ALOGE("%s: the lock is invalid", __FUNCTION__);
return GENLOCK_FAILURE;
}
if (0 == timeout)
ALOGW("%s: timeout = 0", __FUNCTION__);
genlock_lock lock;
lock.fd = hnd->genlockHandle;
lock.timeout = timeout;
if (ioctl(hnd->genlockPrivFd, GENLOCK_IOC_WAIT, &lock)) {
ALOGE("%s: GENLOCK_IOC_WAIT failed (err=%s)", __FUNCTION__,
strerror(errno));
return GENLOCK_FAILURE;
}
}
#endif
return GENLOCK_NO_ERROR;
}
/*
* Convert a write lock that we own to a read lock
*
* @param: handle of the buffer
* @param: timeout value for the wait.
* return: error status.
*/
genlock_status_t genlock_write_to_read(native_handle_t *buffer_handle,
int timeout) {
genlock_status_t ret = GENLOCK_NO_ERROR;
#ifdef USE_GENLOCK
if (0 == timeout) {
ALOGW("%s: trying to lock a buffer with timeout = 0", __FUNCTION__);
}
// Call the private function to perform the lock operation specified.
#ifdef GENLOCK_IOC_DREADLOCK
ret = perform_lock_unlock_operation(buffer_handle, GENLOCK_RDLOCK, timeout,
GENLOCK_WRITE_TO_READ);
#else
// depreciated
ret = perform_lock_unlock_operation(buffer_handle, GENLOCK_RDLOCK,
timeout, 0);
#endif
#endif
return ret;
}