/**
* mei_release - the release function
*
* @inode: pointer to inode structure
* @file: pointer to file structure
*
* returns 0 on success, <0 on error
*/
static int mei_release(struct inode *inode, struct file *file)
{
struct mei_cl *cl = file->private_data;
struct mei_cl_cb *cb;
struct mei_device *dev;
int rets = 0;
if (WARN_ON(!cl || !cl->dev))
return -ENODEV;
dev = cl->dev;
mutex_lock(&dev->device_lock);
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_release(dev, file);
goto out;
}
if (cl->state == MEI_FILE_CONNECTED) {
cl->state = MEI_FILE_DISCONNECTING;
cl_dbg(dev, cl, "disconnecting\n");
rets = mei_cl_disconnect(cl);
}
mei_cl_flush_queues(cl);
cl_dbg(dev, cl, "removing\n");
mei_cl_unlink(cl);
/* free read cb */
cb = NULL;
if (cl->read_cb) {
cb = mei_cl_find_read_cb(cl);
/* Remove entry from read list */
if (cb)
list_del(&cb->list);
cb = cl->read_cb;
cl->read_cb = NULL;
}
file->private_data = NULL;
mei_io_cb_free(cb);
kfree(cl);
out:
mutex_unlock(&dev->device_lock);
return rets;
}
/**
* mei_release - the release function
*
* @inode: pointer to inode structure
* @file: pointer to file structure
*
* Return: 0 on success, <0 on error
*/
static int mei_release(struct inode *inode, struct file *file)
{
struct mei_cl *cl = file->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 (cl == &dev->iamthif_cl) {
rets = mei_amthif_release(dev, file);
goto out;
}
rets = mei_cl_disconnect(cl);
mei_cl_flush_queues(cl, file);
cl_dbg(dev, cl, "removing\n");
mei_cl_unlink(cl);
file->private_data = NULL;
kfree(cl);
out:
mutex_unlock(&dev->device_lock);
return rets;
}
/**
* 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_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_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;
}