static ssize_t network_read(const struct iio_device *dev, void *dst, size_t len,
uint32_t *mask, size_t words)
{
uintptr_t ptr = (uintptr_t) dst;
struct iio_device_pdata *pdata = dev->pdata;
int fd = pdata->fd;
ssize_t ret, read = 0;
char buf[1024];
if (!len || words != (dev->nb_channels + 31) / 32)
return -EINVAL;
snprintf(buf, sizeof(buf), "READBUF %s %lu\r\n",
dev->id, (unsigned long) len);
network_lock_dev(pdata);
ret = write_rwbuf_command(dev, buf, false);
if (ret < 0) {
network_unlock_dev(pdata);
return ret;
}
do {
ret = network_read_mask(fd, mask, words);
if (!ret)
break;
if (ret < 0) {
iio_strerror(-ret, buf, sizeof(buf));
ERROR("Unable to read mask: %s\n", buf);
network_unlock_dev(pdata);
return read ? read : ret;
}
mask = NULL; /* We read the mask only once */
ret = read_all((void *) ptr, ret, fd);
if (ret < 0) {
iio_strerror(-ret, buf, sizeof(buf));
ERROR("Unable to read response to READ: %s\n", buf);
network_unlock_dev(pdata);
return read ? read : ret;
}
ptr += ret;
read += ret;
len -= ret;
} while (len);
network_unlock_dev(pdata);
return read;
}
static ssize_t network_get_buffer(const struct iio_device *dev,
void **addr_ptr, size_t bytes_used,
uint32_t *mask, size_t words)
{
struct iio_device_pdata *pdata = dev->pdata;
ssize_t ret, read = 0;
int memfd;
bool tx;
if (pdata->is_cyclic)
return -ENOSYS;
/* We check early that the temporary file can be created, so that we can
* return -ENOSYS in case it fails, which will indicate that the
* high-speed interface is not available.
*
* O_TMPFILE -> Linux 3.11.
* TODO: use memfd_create (Linux 3.17) */
memfd = open(P_tmpdir, O_RDWR | O_TMPFILE | O_EXCL, S_IRWXU);
if (memfd < 0)
return -ENOSYS;
if (!addr_ptr || words != (dev->nb_channels + 31) / 32) {
close(memfd);
return -EINVAL;
}
if (pdata->mmap_addr)
munmap(pdata->mmap_addr, pdata->mmap_len);
if (pdata->mmap_addr && pdata->is_tx) {
char buf[1024];
snprintf(buf, sizeof(buf), "WRITEBUF %s %lu\r\n",
dev->id, (unsigned long) bytes_used);
iio_mutex_lock(pdata->lock);
ret = write_rwbuf_command(dev, buf, false);
if (ret < 0)
goto err_close_memfd;
ret = network_do_splice(pdata->fd, pdata->memfd, bytes_used);
if (ret < 0)
goto err_close_memfd;
pdata->wait_for_err_code = true;
iio_mutex_unlock(pdata->lock);
}
if (pdata->memfd >= 0)
close(pdata->memfd);
pdata->memfd = memfd;
ret = (ssize_t) ftruncate(pdata->memfd, pdata->mmap_len);
if (ret < 0) {
ret = -errno;
ERROR("Unable to truncate temp file: %zi\n", -ret);
return ret;
}
if (!pdata->is_tx) {
char buf[1024];
size_t len = pdata->mmap_len;
snprintf(buf, sizeof(buf), "READBUF %s %lu\r\n",
dev->id, (unsigned long) len);
iio_mutex_lock(pdata->lock);
ret = write_rwbuf_command(dev, buf, false);
if (ret < 0)
goto err_unlock;
do {
ret = network_read_mask(pdata->fd, mask, words);
if (!ret)
break;
if (ret < 0)
goto err_unlock;
mask = NULL; /* We read the mask only once */
ret = network_do_splice(pdata->memfd, pdata->fd, ret);
if (ret < 0)
goto err_unlock;
read += ret;
len -= ret;
} while (len);
iio_mutex_unlock(pdata->lock);
}
pdata->mmap_addr = mmap(NULL, pdata->mmap_len,
PROT_READ | PROT_WRITE, MAP_SHARED, pdata->memfd, 0);
if (pdata->mmap_addr == MAP_FAILED) {
pdata->mmap_addr = NULL;
ret = -errno;
ERROR("Unable to mmap: %zi\n", -ret);
return ret;
}
*addr_ptr = pdata->mmap_addr;
return read ? read : bytes_used;
err_close_memfd:
close(memfd);
err_unlock:
iio_mutex_unlock(pdata->lock);
return ret;
}