floppy: add defines for sizes of cmd & reply buffers of floppy_raw_cmd

Use FD_RAW_CMD_SIZE, FD_RAW_REPLY_SIZE defines instead of magic numbers
for cmd & reply buffers of struct floppy_raw_cmd. Remove local to
floppy.c MAX_REPLIES define, as it is now FD_RAW_REPLY_SIZE.
FD_RAW_CMD_FULLSIZE added as we allow command to also fill reply_count
and reply fields.

Link: https://lore.kernel.org/r/20200501134416.72248-4-efremov@linux.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Denis Efremov <efremov@linux.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/include/uapi/linux/fd.h b/include/uapi/linux/fd.h
index 3f6b7be4c096..2e9c2c1c18e6 100644
--- a/include/uapi/linux/fd.h
+++ b/include/uapi/linux/fd.h
@@ -360,10 +360,20 @@ struct floppy_raw_cmd {
 	int buffer_length; /* length of allocated buffer */
 
 	unsigned char rate;
+
+#define FD_RAW_CMD_SIZE 16
+#define FD_RAW_REPLY_SIZE 16
+#define FD_RAW_CMD_FULLSIZE (FD_RAW_CMD_SIZE + 1 + FD_RAW_REPLY_SIZE)
+
+	/* The command may take up the space initially intended for the reply
+	 * and the reply count. Needed for long 82078 commands such as RESTORE,
+	 * which takes 17 command bytes.
+	 */
+
 	unsigned char cmd_count;
-	unsigned char cmd[16];
+	unsigned char cmd[FD_RAW_CMD_SIZE];
 	unsigned char reply_count;
-	unsigned char reply[16];
+	unsigned char reply[FD_RAW_REPLY_SIZE];
 	int track;
 	int resultcode;