v4.19.13 snapshot.
diff --git a/drivers/usb/storage/protocol.h b/drivers/usb/storage/protocol.h
new file mode 100644
index 0000000..072f1ff
--- /dev/null
+++ b/drivers/usb/storage/protocol.h
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for USB Mass Storage compliant devices
+ * Protocol Functions Header File
+ *
+ * Current development and maintenance by:
+ * (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
+ *
+ * This driver is based on the 'USB Mass Storage Class' document. This
+ * describes in detail the protocol used to communicate with such
+ * devices. Clearly, the designers had SCSI and ATAPI commands in
+ * mind when they created this document. The commands are all very
+ * similar to commands in the SCSI-II and ATAPI specifications.
+ *
+ * It is important to note that in a number of cases this class
+ * exhibits class-specific exemptions from the USB specification.
+ * Notably the usage of NAK, STALL and ACK differs from the norm, in
+ * that they are used to communicate wait, failed and OK on commands.
+ *
+ * Also, for certain devices, the interrupt endpoint is used to convey
+ * status of a command.
+ */
+
+#ifndef _PROTOCOL_H_
+#define _PROTOCOL_H_
+
+/* Protocol handling routines */
+extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*);
+extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
+extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
+ struct us_data*);
+
+/* struct scsi_cmnd transfer buffer access utilities */
+enum xfer_buf_dir {TO_XFER_BUF, FROM_XFER_BUF};
+
+extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
+ unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
+ unsigned int *offset, enum xfer_buf_dir dir);
+
+extern void usb_stor_set_xfer_buf(unsigned char *buffer,
+ unsigned int buflen, struct scsi_cmnd *srb);
+#endif