block: add bsg helper library
This moves the FC classes bsg code to the block layer and
makes it a lib so that other classes like iscsi and SAS can use it.
It is helpful because working with the request queue, bios,
creating scatterlists, etc are a pain that the LLD does not
have to worry about with normal IOs and should not have to
worry about for bsg requests.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/include/linux/bsg-lib.h b/include/linux/bsg-lib.h
new file mode 100644
index 0000000..f55ab8c
--- /dev/null
+++ b/include/linux/bsg-lib.h
@@ -0,0 +1,73 @@
+/*
+ * BSG helper library
+ *
+ * Copyright (C) 2008 James Smart, Emulex Corporation
+ * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2011 Mike Christie
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+#ifndef _BLK_BSG_
+#define _BLK_BSG_
+
+#include <linux/blkdev.h>
+
+struct request;
+struct device;
+struct scatterlist;
+struct request_queue;
+
+struct bsg_buffer {
+ unsigned int payload_len;
+ int sg_cnt;
+ struct scatterlist *sg_list;
+};
+
+struct bsg_job {
+ struct device *dev;
+ struct request *req;
+
+ /* Transport/driver specific request/reply structs */
+ void *request;
+ void *reply;
+
+ unsigned int request_len;
+ unsigned int reply_len;
+ /*
+ * On entry : reply_len indicates the buffer size allocated for
+ * the reply.
+ *
+ * Upon completion : the message handler must set reply_len
+ * to indicates the size of the reply to be returned to the
+ * caller.
+ */
+
+ /* DMA payloads for the request/response */
+ struct bsg_buffer request_payload;
+ struct bsg_buffer reply_payload;
+
+ void *dd_data; /* Used for driver-specific storage */
+};
+
+void bsg_job_done(struct bsg_job *job, int result,
+ unsigned int reply_payload_rcv_len);
+int bsg_setup_queue(struct device *dev, struct request_queue *q, char *name,
+ bsg_job_fn *job_fn, int dd_job_size);
+void bsg_request_fn(struct request_queue *q);
+void bsg_remove_queue(struct request_queue *q);
+void bsg_goose_queue(struct request_queue *q);
+
+#endif