mei: amthif: drop mei_amthif_read

mei_amthif_read have only one difference from mei_read, it is not
calling mei_read_start().
Make mei_read_start return immediately for amthif client and drop the
special mei_amthif_read function.
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/amthif.c

@@ -84,106 +84,6 @@ int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
 	return ret;
 }
 
-/**
- * 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_amthif_read_start - queue message for sending read credential
  *

drivers/misc/mei/client.c

@@ -1462,7 +1462,7 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
 		return  -ENOTTY;
 	}
 
-	if (mei_cl_is_fixed_address(cl))
+	if (mei_cl_is_fixed_address(cl) || cl == &dev->iamthif_cl)
 		return 0;
 
 	/* HW currently supports only one pending read */

drivers/misc/mei/main.c

@@ -164,11 +164,6 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
 		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)
 		goto copy_buffer;

drivers/misc/mei/mei_dev.h

@@ -564,9 +564,6 @@ void mei_amthif_reset_params(struct mei_device *dev);
 
 int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl);
 
-int mei_amthif_read(struct mei_device *dev, struct file *file,
-		char __user *ubuf, size_t length, loff_t *offset);
-
 unsigned int mei_amthif_poll(struct file *file, poll_table *wait);
 
 int mei_amthif_release(struct mei_device *dev, struct file *file);