/**
* mei_amthif_read_start - queue message for sending read credential
*
* @cl: host client
* @file: file pointer of message recipient
*
* Return: 0 on success, <0 on failure.
*/
static int mei_amthif_read_start(struct mei_cl *cl, const struct file *file)
{
struct mei_device *dev = cl->dev;
struct mei_cl_cb *cb;
int rets;
cb = mei_io_cb_init(cl, MEI_FOP_READ, file);
if (!cb) {
rets = -ENOMEM;
goto err;
}
rets = mei_io_cb_alloc_buf(cb, mei_cl_mtu(cl));
if (rets)
goto err;
list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
dev->iamthif_state = MEI_IAMTHIF_READING;
dev->iamthif_fp = cb->fp;
dev->iamthif_current_cb = cb;
return 0;
err:
mei_io_cb_free(cb);
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
*
* returns >=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;
int id;
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;
}
id = mei_me_cl_by_id(dev, cl->me_client_id);
if (id < 0) {
rets = -ENOTTY;
goto out;
}
if (length == 0) {
rets = 0;
goto out;
}
if (length > dev->me_clients[id].props.max_msg_length) {
rets = -EFBIG;
goto out;
}
if (cl->state != MEI_FILE_CONNECTED) {
dev_err(&dev->pdev->dev, "host client = %d, is not connected to ME client = %d",
cl->host_client_id, cl->me_client_id);
rets = -ENODEV;
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) ||
cl->reading_state == MEI_READ_COMPLETE) {
*offset = 0;
list_del(&write_cb->list);
mei_io_cb_free(write_cb);
write_cb = NULL;
}
}
}
/* free entry used in read */
if (cl->reading_state == MEI_READ_COMPLETE) {
*offset = 0;
write_cb = mei_cl_find_read_cb(cl);
if (write_cb) {
list_del(&write_cb->list);
mei_io_cb_free(write_cb);
write_cb = NULL;
cl->reading_state = MEI_IDLE;
cl->read_cb = NULL;
}
} else if (cl->reading_state == MEI_IDLE)
*offset = 0;
write_cb = mei_io_cb_init(cl, file);
if (!write_cb) {
dev_err(&dev->pdev->dev, "write cb allocation failed\n");
rets = -ENOMEM;
goto out;
}
rets = mei_io_cb_alloc_req_buf(write_cb, length);
if (rets)
goto out;
rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
if (rets) {
dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
rets = -EFAULT;
goto out;
}
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_write(dev, write_cb);
if (rets) {
dev_err(&dev->pdev->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;
}