/**
* mei_wd_ops_start - wd start command from the watchdog core.
*
* @wd_dev: watchdog device struct
*
* Return: 0 if success, negative errno code for failure
*/
static int mei_wd_ops_start(struct watchdog_device *wd_dev)
{
struct mei_device *dev;
struct mei_cl *cl;
int err = -ENODEV;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
cl = &dev->wd_cl;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
dev_dbg(dev->dev, "wd: dev_state != MEI_DEV_ENABLED dev_state = %s\n",
mei_dev_state_str(dev->dev_state));
goto end_unlock;
}
if (!mei_cl_is_connected(cl)) {
cl_dbg(dev, cl, "MEI Driver is not connected to Watchdog Client\n");
goto end_unlock;
}
mei_wd_set_start_timeout(dev, dev->wd_timeout);
err = 0;
end_unlock:
mutex_unlock(&dev->device_lock);
return err;
}
/**
* mei_amthif_host_init - mei initialization amthif client.
*
* @dev: the device structure
* @me_cl: me client
*
* Return: 0 on success, <0 on failure.
*/
int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
{
struct mei_cl *cl = &dev->iamthif_cl;
int ret;
mutex_lock(&dev->device_lock);
if (mei_cl_is_connected(cl)) {
ret = 0;
goto out;
}
dev->iamthif_state = MEI_IAMTHIF_IDLE;
mei_cl_init(cl, dev);
ret = mei_cl_link(cl);
if (ret < 0) {
dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
goto out;
}
ret = mei_cl_connect(cl, me_cl, NULL);
out:
mutex_unlock(&dev->device_lock);
return ret;
}
/**
* mei_fasync - asynchronous io support
*
* @fd: file descriptor
* @file: pointer to file structure
* @band: band bitmap
*
* Return: negative on error,
* 0 if it did no changes,
* and positive a process was added or deleted
*/
static int mei_fasync(int fd, struct file *file, int band)
{
struct mei_cl *cl = file->private_data;
if (!mei_cl_is_connected(cl))
return -ENODEV;
return fasync_helper(fd, file, band, &cl->ev_async);
}
/**
* mei_poll - the poll function
*
* @file: pointer to file structure
* @wait: pointer to poll_table structure
*
* returns poll mask
*/
static unsigned int mei_poll(struct file *file, poll_table *wait)
{
struct mei_cl *cl = file->private_data;
struct mei_device *dev;
unsigned int mask = 0;
if (WARN_ON(!cl || !cl->dev))
return POLLERR;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (!mei_cl_is_connected(cl)) {
mask = POLLERR;
goto out;
}
mutex_unlock(&dev->device_lock);
if (cl == &dev->iamthif_cl)
return mei_amthif_poll(dev, file, wait);
poll_wait(file, &cl->tx_wait, wait);
mutex_lock(&dev->device_lock);
if (!mei_cl_is_connected(cl)) {
mask = POLLERR;
goto out;
}
if (MEI_WRITE_COMPLETE == cl->writing_state)
mask |= (POLLIN | POLLRDNORM);
out:
mutex_unlock(&dev->device_lock);
return mask;
}
/**
* mei_fsync - the fsync handler
*
* @fp: pointer to file structure
* @start: unused
* @end: unused
* @datasync: unused
*
* Return: 0 on success, -ENODEV if client is not connected
*/
static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
{
struct mei_cl *cl = fp->private_data;
struct mei_device *dev;
int rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
while (mei_cl_is_write_queued(cl)) {
mutex_unlock(&dev->device_lock);
rets = wait_event_interruptible(cl->tx_wait,
cl->writing_state == MEI_WRITE_COMPLETE ||
!mei_cl_is_connected(cl));
mutex_lock(&dev->device_lock);
if (rets) {
if (signal_pending(current))
rets = -EINTR;
goto out;
}
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
}
rets = 0;
out:
mutex_unlock(&dev->device_lock);
return rets;
}
/**
* mei_poll - the poll function
*
* @file: pointer to file structure
* @wait: pointer to poll_table structure
*
* Return: poll mask
*/
static __poll_t mei_poll(struct file *file, poll_table *wait)
{
__poll_t req_events = poll_requested_events(wait);
struct mei_cl *cl = file->private_data;
struct mei_device *dev;
__poll_t mask = 0;
bool notify_en;
if (WARN_ON(!cl || !cl->dev))
return EPOLLERR;
dev = cl->dev;
mutex_lock(&dev->device_lock);
notify_en = cl->notify_en && (req_events & EPOLLPRI);
if (dev->dev_state != MEI_DEV_ENABLED ||
!mei_cl_is_connected(cl)) {
mask = EPOLLERR;
goto out;
}
if (notify_en) {
poll_wait(file, &cl->ev_wait, wait);
if (cl->notify_ev)
mask |= EPOLLPRI;
}
if (req_events & (EPOLLIN | EPOLLRDNORM)) {
poll_wait(file, &cl->rx_wait, wait);
if (!list_empty(&cl->rd_completed))
mask |= EPOLLIN | EPOLLRDNORM;
else
mei_cl_read_start(cl, mei_cl_mtu(cl), file);
}
if (req_events & (POLLOUT | POLLWRNORM)) {
poll_wait(file, &cl->tx_wait, wait);
if (cl->tx_cb_queued < dev->tx_queue_limit)
mask |= POLLOUT | POLLWRNORM;
}
out:
mutex_unlock(&dev->device_lock);
return mask;
}
/**
* mei_poll - the poll function
*
* @file: pointer to file structure
* @wait: pointer to poll_table structure
*
* Return: poll mask
*/
static unsigned int mei_poll(struct file *file, poll_table *wait)
{
unsigned long req_events = poll_requested_events(wait);
struct mei_cl *cl = file->private_data;
struct mei_device *dev;
unsigned int mask = 0;
bool notify_en;
if (WARN_ON(!cl || !cl->dev))
return POLLERR;
dev = cl->dev;
mutex_lock(&dev->device_lock);
notify_en = cl->notify_en && (req_events & POLLPRI);
if (dev->dev_state != MEI_DEV_ENABLED ||
!mei_cl_is_connected(cl)) {
mask = POLLERR;
goto out;
}
if (notify_en) {
poll_wait(file, &cl->ev_wait, wait);
if (cl->notify_ev)
mask |= POLLPRI;
}
if (cl == &dev->iamthif_cl) {
mask |= mei_amthif_poll(file, wait);
goto out;
}
if (req_events & (POLLIN | POLLRDNORM)) {
poll_wait(file, &cl->rx_wait, wait);
if (!list_empty(&cl->rd_completed))
mask |= POLLIN | POLLRDNORM;
else
mei_cl_read_start(cl, mei_cl_mtu(cl), file);
}
out:
mutex_unlock(&dev->device_lock);
return mask;
}
/**
* mei_wd_stop - sends watchdog stop message to fw.
*
* @dev: the device structure
*
* Return: 0 if success
* on error:
* -EIO when message send fails
* -EINVAL when invalid message is to be sent
* -ETIME on message timeout
*/
int mei_wd_stop(struct mei_device *dev)
{
struct mei_cl *cl = &dev->wd_cl;
int ret;
if (!mei_cl_is_connected(cl) ||
dev->wd_state != MEI_WD_RUNNING)
return 0;
memcpy(dev->wd_data, mei_stop_wd_params, MEI_WD_STOP_MSG_SIZE);
dev->wd_state = MEI_WD_STOPPING;
ret = mei_cl_flow_ctrl_creds(cl);
if (ret < 0)
goto err;
if (ret && mei_hbuf_acquire(dev)) {
ret = mei_wd_send(dev);
if (ret)
goto err;
dev->wd_pending = false;
} else {
dev->wd_pending = true;
}
mutex_unlock(&dev->device_lock);
ret = wait_event_timeout(dev->wait_stop_wd,
dev->wd_state == MEI_WD_IDLE,
msecs_to_jiffies(MEI_WD_STOP_TIMEOUT));
mutex_lock(&dev->device_lock);
if (dev->wd_state != MEI_WD_IDLE) {
/* timeout */
ret = -ETIME;
dev_warn(dev->dev, "wd: stop failed to complete ret=%d\n", ret);
goto err;
}
dev_dbg(dev->dev, "wd: stop completed after %u msec\n",
MEI_WD_STOP_TIMEOUT - jiffies_to_msecs(ret));
return 0;
err:
return ret;
}
/**
* mei_wd_ops_ping - wd ping command from the watchdog core.
*
* @wd_dev: watchdog device struct
*
* Return: 0 if success, negative errno code for failure
*/
static int mei_wd_ops_ping(struct watchdog_device *wd_dev)
{
struct mei_device *dev;
struct mei_cl *cl;
int ret;
dev = watchdog_get_drvdata(wd_dev);
if (!dev)
return -ENODEV;
cl = &dev->wd_cl;
mutex_lock(&dev->device_lock);
if (!mei_cl_is_connected(cl)) {
cl_err(dev, cl, "wd: not connected.\n");
ret = -ENODEV;
goto end;
}
dev->wd_state = MEI_WD_RUNNING;
ret = mei_cl_flow_ctrl_creds(cl);
if (ret < 0)
goto end;
/* Check if we can send the ping to HW*/
if (ret && mei_hbuf_acquire(dev)) {
dev_dbg(dev->dev, "wd: sending ping\n");
ret = mei_wd_send(dev);
if (ret)
goto end;
dev->wd_pending = false;
} else {
dev->wd_pending = true;
}
end:
mutex_unlock(&dev->device_lock);
return ret;
}
/**
* mei_ioctl_connect_client - the connect to fw client IOCTL function
*
* @file: private data of the file object
* @data: IOCTL connect data, input and output parameters
*
* Locking: called under "dev->device_lock" lock
*
* Return: 0 on success, <0 on failure.
*/
static int mei_ioctl_connect_client(struct file *file,
struct mei_connect_client_data *data)
{
struct mei_device *dev;
struct mei_client *client;
struct mei_me_client *me_cl;
struct mei_cl *cl;
int rets;
cl = file->private_data;
dev = cl->dev;
if (dev->dev_state != MEI_DEV_ENABLED)
return -ENODEV;
if (cl->state != MEI_FILE_INITIALIZING &&
cl->state != MEI_FILE_DISCONNECTED)
return -EBUSY;
/* find ME client we're trying to connect to */
me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
if (!me_cl) {
dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
&data->in_client_uuid);
rets = -ENOTTY;
goto end;
}
if (me_cl->props.fixed_address) {
bool forbidden = dev->override_fixed_address ?
!dev->allow_fixed_address : !dev->hbm_f_fa_supported;
if (forbidden) {
dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
&data->in_client_uuid);
rets = -ENOTTY;
goto end;
}
}
dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
me_cl->client_id);
dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
me_cl->props.protocol_version);
dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
me_cl->props.max_msg_length);
/* if we're connecting to amthif client then we will use the
* existing connection
*/
if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
dev_dbg(dev->dev, "FW Client is amthi\n");
if (!mei_cl_is_connected(&dev->iamthif_cl)) {
rets = -ENODEV;
goto end;
}
mei_cl_unlink(cl);
kfree(cl);
cl = NULL;
dev->iamthif_open_count++;
file->private_data = &dev->iamthif_cl;
client = &data->out_client_properties;
client->max_msg_length = me_cl->props.max_msg_length;
client->protocol_version = me_cl->props.protocol_version;
rets = dev->iamthif_cl.status;
goto end;
}
/* prepare the output buffer */
client = &data->out_client_properties;
client->max_msg_length = me_cl->props.max_msg_length;
client->protocol_version = me_cl->props.protocol_version;
dev_dbg(dev->dev, "Can connect?\n");
rets = mei_cl_connect(cl, me_cl, file);
end:
mei_me_cl_put(me_cl);
return rets;
}
/**
* mei_write - the write function.
*
* @file: pointer to file structure
* @ubuf: pointer to user buffer
* @length: buffer length
* @offset: data offset in buffer
*
* Return: >=0 data length on success , <0 on error
*/
static ssize_t mei_write(struct file *file, const char __user *ubuf,
size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_cl_cb *cb;
struct mei_device *dev;
int rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
if (!mei_cl_is_connected(cl)) {
cl_err(dev, cl, "is not connected");
rets = -ENODEV;
goto out;
}
if (!mei_me_cl_is_active(cl->me_cl)) {
rets = -ENOTTY;
goto out;
}
if (length > mei_cl_mtu(cl)) {
rets = -EFBIG;
goto out;
}
if (length == 0) {
rets = 0;
goto out;
}
*offset = 0;
cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
if (!cb) {
rets = -ENOMEM;
goto out;
}
rets = copy_from_user(cb->buf.data, ubuf, length);
if (rets) {
dev_dbg(dev->dev, "failed to copy data from userland\n");
rets = -EFAULT;
mei_io_cb_free(cb);
goto out;
}
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_write(cl, cb);
if (!rets)
rets = length;
goto out;
}
rets = mei_cl_write(cl, cb);
out:
mutex_unlock(&dev->device_lock);
return rets;
}
/**
* mei_read - the read function.
*
* @file: pointer to file structure
* @ubuf: pointer to user buffer
* @length: buffer length
* @offset: data offset in buffer
*
* Return: >=0 data length on success , <0 on error
*/
static ssize_t mei_read(struct file *file, char __user *ubuf,
size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_device *dev;
struct mei_cl_cb *cb = NULL;
bool nonblock = !!(file->f_flags & O_NONBLOCK);
int rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
if (length == 0) {
rets = 0;
goto out;
}
if (ubuf == NULL) {
rets = -EMSGSIZE;
goto out;
}
cb = mei_cl_read_cb(cl, file);
if (cb)
goto copy_buffer;
if (*offset > 0)
*offset = 0;
rets = mei_cl_read_start(cl, length, file);
if (rets && rets != -EBUSY) {
cl_dbg(dev, cl, "mei start read failure status = %d\n", rets);
goto out;
}
if (nonblock) {
rets = -EAGAIN;
goto out;
}
if (rets == -EBUSY &&
!mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, file)) {
rets = -ENOMEM;
goto out;
}
do {
mutex_unlock(&dev->device_lock);
if (wait_event_interruptible(cl->rx_wait,
(!list_empty(&cl->rd_completed)) ||
(!mei_cl_is_connected(cl)))) {
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
mutex_lock(&dev->device_lock);
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
cb = mei_cl_read_cb(cl, file);
} while (!cb);
copy_buffer:
/* now copy the data to user space */
if (cb->status) {
rets = cb->status;
cl_dbg(dev, cl, "read operation failed %d\n", rets);
goto free;
}
cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
cb->buf.size, cb->buf_idx, *offset);
if (*offset >= cb->buf_idx) {
rets = 0;
goto free;
}
/* length is being truncated to PAGE_SIZE,
* however buf_idx may point beyond that */
length = min_t(size_t, length, cb->buf_idx - *offset);
if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
dev_dbg(dev->dev, "failed to copy data to userland\n");
rets = -EFAULT;
goto free;
}
rets = length;
*offset += length;
/* not all data was read, keep the cb */
if (*offset < cb->buf_idx)
goto out;
free:
mei_io_cb_free(cb);
*offset = 0;
out:
cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
mutex_unlock(&dev->device_lock);
return rets;
}
/**
* mei_write - the write function.
*
* @file: pointer to file structure
* @ubuf: pointer to user buffer
* @length: buffer length
* @offset: data offset in buffer
*
* Return: >=0 data length on success , <0 on error
*/
static ssize_t mei_write(struct file *file, const char __user *ubuf,
size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_cl_cb *cb;
struct mei_device *dev;
int rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
if (!mei_cl_is_connected(cl)) {
cl_err(dev, cl, "is not connected");
rets = -ENODEV;
goto out;
}
if (!mei_me_cl_is_active(cl->me_cl)) {
rets = -ENOTTY;
goto out;
}
if (length > mei_cl_mtu(cl)) {
rets = -EFBIG;
goto out;
}
if (length == 0) {
rets = 0;
goto out;
}
while (cl->tx_cb_queued >= dev->tx_queue_limit) {
if (file->f_flags & O_NONBLOCK) {
rets = -EAGAIN;
goto out;
}
mutex_unlock(&dev->device_lock);
rets = wait_event_interruptible(cl->tx_wait,
cl->writing_state == MEI_WRITE_COMPLETE ||
(!mei_cl_is_connected(cl)));
mutex_lock(&dev->device_lock);
if (rets) {
if (signal_pending(current))
rets = -EINTR;
goto out;
}
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
}
*offset = 0;
cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
if (!cb) {
rets = -ENOMEM;
goto out;
}
rets = copy_from_user(cb->buf.data, ubuf, length);
if (rets) {
dev_dbg(dev->dev, "failed to copy data from userland\n");
rets = -EFAULT;
mei_io_cb_free(cb);
goto out;
}
rets = mei_cl_write(cl, cb);
out:
mutex_unlock(&dev->device_lock);
return rets;
}
/**
* mei_amthif_read - read data from AMTHIF client
*
* @dev: the device structure
* @file: pointer to file object
* @ubuf: pointer to user data in user space
* @length: data length to read
* @offset: data read offset
*
* Locking: called under "dev->device_lock" lock
*
* Return:
* returned data length on success,
* zero if no data to read,
* negative on failure.
*/
int mei_amthif_read(struct mei_device *dev, struct file *file,
char __user *ubuf, size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_cl_cb *cb;
int rets;
int wait_ret;
dev_dbg(dev->dev, "checking amthif data\n");
cb = mei_cl_read_cb(cl, file);
/* Check for if we can block or not*/
if (cb == NULL && file->f_flags & O_NONBLOCK)
return -EAGAIN;
dev_dbg(dev->dev, "waiting for amthif data\n");
while (cb == NULL) {
/* unlock the Mutex */
mutex_unlock(&dev->device_lock);
wait_ret = wait_event_interruptible(cl->rx_wait,
!list_empty(&cl->rd_completed) ||
!mei_cl_is_connected(cl));
/* Locking again the Mutex */
mutex_lock(&dev->device_lock);
if (wait_ret)
return -ERESTARTSYS;
if (!mei_cl_is_connected(cl)) {
rets = -ENODEV;
goto out;
}
cb = mei_cl_read_cb(cl, file);
}
if (cb->status) {
rets = cb->status;
dev_dbg(dev->dev, "read operation failed %d\n", rets);
goto free;
}
dev_dbg(dev->dev, "Got amthif data\n");
/* if the whole message will fit remove it from the list */
if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
list_del_init(&cb->list);
else if (cb->buf_idx <= *offset) {
/* end of the message has been reached */
list_del_init(&cb->list);
rets = 0;
goto free;
}
/* else means that not full buffer will be read and do not
* remove message from deletion list
*/
dev_dbg(dev->dev, "amthif cb->buf.size - %zu cb->buf_idx - %zu\n",
cb->buf.size, cb->buf_idx);
/* length is being truncated to PAGE_SIZE, however,
* the buf_idx may point beyond */
length = min_t(size_t, length, (cb->buf_idx - *offset));
if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
dev_dbg(dev->dev, "failed to copy data to userland\n");
rets = -EFAULT;
} else {
rets = length;
if ((*offset + length) < cb->buf_idx) {
*offset += length;
goto out;
}
}
free:
dev_dbg(dev->dev, "free amthif cb memory.\n");
*offset = 0;
mei_io_cb_free(cb);
out:
return rets;
}
/**
* mei_write - the write function.
*
* @file: pointer to file structure
* @ubuf: pointer to user buffer
* @length: buffer length
* @offset: data offset in buffer
*
* Return: >=0 data length on success , <0 on error
*/
static ssize_t mei_write(struct file *file, const char __user *ubuf,
size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_cl_cb *write_cb = NULL;
struct mei_device *dev;
unsigned long timeout = 0;
int rets;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
if (!mei_cl_is_connected(cl)) {
cl_err(dev, cl, "is not connected");
rets = -ENODEV;
goto out;
}
if (!mei_me_cl_is_active(cl->me_cl)) {
rets = -ENOTTY;
goto out;
}
if (length > mei_cl_mtu(cl)) {
rets = -EFBIG;
goto out;
}
if (length == 0) {
rets = 0;
goto out;
}
if (cl == &dev->iamthif_cl) {
write_cb = mei_amthif_find_read_list_entry(dev, file);
if (write_cb) {
timeout = write_cb->read_time +
mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
if (time_after(jiffies, timeout)) {
*offset = 0;
mei_io_cb_free(write_cb);
write_cb = NULL;
}
}
}
*offset = 0;
write_cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
if (!write_cb) {
rets = -ENOMEM;
goto out;
}
rets = copy_from_user(write_cb->buf.data, ubuf, length);
if (rets) {
dev_dbg(dev->dev, "failed to copy data from userland\n");
rets = -EFAULT;
goto out;
}
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_write(cl, write_cb);
if (rets) {
dev_err(dev->dev,
"amthif write failed with status = %d\n", rets);
goto out;
}
mutex_unlock(&dev->device_lock);
return length;
}
rets = mei_cl_write(cl, write_cb, false);
out:
mutex_unlock(&dev->device_lock);
if (rets < 0)
mei_io_cb_free(write_cb);
return rets;
}
/**
* mei_read - the read function.
*
* @file: pointer to file structure
* @ubuf: pointer to user buffer
* @length: buffer length
* @offset: data offset in buffer
*
* Return: >=0 data length on success , <0 on error
*/
static ssize_t mei_read(struct file *file, char __user *ubuf,
size_t length, loff_t *offset)
{
struct mei_cl *cl = file->private_data;
struct mei_device *dev;
struct mei_cl_cb *cb = NULL;
int rets;
int err;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (dev->dev_state != MEI_DEV_ENABLED) {
rets = -ENODEV;
goto out;
}
if (length == 0) {
rets = 0;
goto out;
}
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_read(dev, file, ubuf, length, offset);
goto out;
}
cb = mei_cl_read_cb(cl, file);
if (cb) {
/* read what left */
if (cb->buf_idx > *offset)
goto copy_buffer;
/* offset is beyond buf_idx we have no more data return 0 */
if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
rets = 0;
goto free;
}
/* Offset needs to be cleaned for contiguous reads*/
if (cb->buf_idx == 0 && *offset > 0)
*offset = 0;
} else if (*offset > 0) {
*offset = 0;
}
err = mei_cl_read_start(cl, length, file);
if (err && err != -EBUSY) {
cl_dbg(dev, cl, "mei start read failure status = %d\n", err);
rets = err;
goto out;
}
if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
if (file->f_flags & O_NONBLOCK) {
rets = -EAGAIN;
goto out;
}
mutex_unlock(&dev->device_lock);
if (wait_event_interruptible(cl->rx_wait,
(!list_empty(&cl->rd_completed)) ||
(!mei_cl_is_connected(cl)))) {
if (signal_pending(current))
return -EINTR;
return -ERESTARTSYS;
}
mutex_lock(&dev->device_lock);
if (!mei_cl_is_connected(cl)) {
rets = -EBUSY;
goto out;
}
}
cb = mei_cl_read_cb(cl, file);
if (!cb) {
if (mei_cl_is_fixed_address(cl) && dev->allow_fixed_address) {
cb = mei_cl_read_cb(cl, NULL);
if (cb)
goto copy_buffer;
}
rets = 0;
goto out;
}
copy_buffer:
/* now copy the data to user space */
if (cb->status) {
rets = cb->status;
cl_dbg(dev, cl, "read operation failed %d\n", rets);
goto free;
}
cl_dbg(dev, cl, "buf.size = %d buf.idx = %ld\n",
cb->buf.size, cb->buf_idx);
if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
rets = -EMSGSIZE;
goto free;
}
/* length is being truncated to PAGE_SIZE,
* however buf_idx may point beyond that */
length = min_t(size_t, length, cb->buf_idx - *offset);
if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
dev_dbg(dev->dev, "failed to copy data to userland\n");
rets = -EFAULT;
goto free;
}
rets = length;
*offset += length;
if ((unsigned long)*offset < cb->buf_idx)
goto out;
free:
mei_io_cb_free(cb);
out:
cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
mutex_unlock(&dev->device_lock);
return rets;
}