[deliverable/linux.git] / net / sunrpc / xprtrdma / svc_rdma_marshal.c

/*
 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the BSD-type
 * license below:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *      Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 *      Neither the name of the Network Appliance, Inc. nor the names of
 *      its contributors may be used to endorse or promote products
 *      derived from this software without specific prior written
 *      permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Author: Tom Tucker <tom@opengridcomputing.com>
 */

#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/debug.h>
#include <asm/unaligned.h>
#include <linux/sunrpc/rpc_rdma.h>
#include <linux/sunrpc/svc_rdma.h>

#define RPCDBG_FACILITY	RPCDBG_SVCXPRT

/*
 * Decodes a read chunk list. The expected format is as follows:
 *    descrim  : xdr_one
 *    position : u32 offset into XDR stream
 *    handle   : u32 RKEY
 *    . . .
 *  end-of-list: xdr_zero
 */
static u32 *decode_read_list(u32 *va, u32 *vaend)
{
	struct rpcrdma_read_chunk *ch = (struct rpcrdma_read_chunk *)va;

	while (ch->rc_discrim != xdr_zero) {
		if (((unsigned long)ch + sizeof(struct rpcrdma_read_chunk)) >
		    (unsigned long)vaend) {
			dprintk("svcrdma: vaend=%p, ch=%p\n", vaend, ch);
			return NULL;
		}
		ch++;
	}
	return (u32 *)&ch->rc_position;
}

/*
 * Decodes a write chunk list. The expected format is as follows:
 *    descrim  : xdr_one
 *    nchunks  : <count>
 *       handle   : u32 RKEY              ---+
 *       length   : u32 <len of segment>     |
 *       offset   : remove va                + <count>
 *       . . .                               |
 *                                        ---+
 */
static u32 *decode_write_list(u32 *va, u32 *vaend)
{
	unsigned long start, end;
	int nchunks;

	struct rpcrdma_write_array *ary =
		(struct rpcrdma_write_array *)va;

	/* Check for not write-array */
	if (ary->wc_discrim == xdr_zero)
		return (u32 *)&ary->wc_nchunks;

	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
	    (unsigned long)vaend) {
		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
		return NULL;
	}
	nchunks = ntohl(ary->wc_nchunks);

	start = (unsigned long)&ary->wc_array[0];
	end = (unsigned long)vaend;
	if (nchunks < 0 ||
	    nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
	    (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
		dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
			ary, nchunks, vaend);
		return NULL;
	}
	/*
	 * rs_length is the 2nd 4B field in wc_target and taking its
	 * address skips the list terminator
	 */
	return (u32 *)&ary->wc_array[nchunks].wc_target.rs_length;
}

static u32 *decode_reply_array(u32 *va, u32 *vaend)
{
	unsigned long start, end;
	int nchunks;
	struct rpcrdma_write_array *ary =
		(struct rpcrdma_write_array *)va;

	/* Check for no reply-array */
	if (ary->wc_discrim == xdr_zero)
		return (u32 *)&ary->wc_nchunks;

	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
	    (unsigned long)vaend) {
		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
		return NULL;
	}
	nchunks = ntohl(ary->wc_nchunks);

	start = (unsigned long)&ary->wc_array[0];
	end = (unsigned long)vaend;
	if (nchunks < 0 ||
	    nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
	    (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
		dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
			ary, nchunks, vaend);
		return NULL;
	}
	return (u32 *)&ary->wc_array[nchunks];
}

int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
			    struct svc_rqst *rqstp)
{
	struct rpcrdma_msg *rmsgp = NULL;
	u32 *va;
	u32 *vaend;
	u32 hdr_len;

	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;

	/* Verify that there's enough bytes for header + something */
	if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
		dprintk("svcrdma: header too short = %d\n",
			rqstp->rq_arg.len);
		return -EINVAL;
	}

	/* Decode the header */
	rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
	rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
	rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
	rmsgp->rm_type = ntohl(rmsgp->rm_type);

	if (rmsgp->rm_vers != RPCRDMA_VERSION)
		return -ENOSYS;

	/* Pull in the extra for the padded case and bump our pointer */
	if (rmsgp->rm_type == RDMA_MSGP) {
		int hdrlen;
		rmsgp->rm_body.rm_padded.rm_align =
			ntohl(rmsgp->rm_body.rm_padded.rm_align);
		rmsgp->rm_body.rm_padded.rm_thresh =
			ntohl(rmsgp->rm_body.rm_padded.rm_thresh);

		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
		rqstp->rq_arg.head[0].iov_base = va;
		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
		rqstp->rq_arg.head[0].iov_len -= hdrlen;
		if (hdrlen > rqstp->rq_arg.len)
			return -EINVAL;
		return hdrlen;
	}

	/* The chunk list may contain either a read chunk list or a write
	 * chunk list and a reply chunk list.
	 */
	va = &rmsgp->rm_body.rm_chunks[0];
	vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
	va = decode_read_list(va, vaend);
	if (!va)
		return -EINVAL;
	va = decode_write_list(va, vaend);
	if (!va)
		return -EINVAL;
	va = decode_reply_array(va, vaend);
	if (!va)
		return -EINVAL;

	rqstp->rq_arg.head[0].iov_base = va;
	hdr_len = (unsigned long)va - (unsigned long)rmsgp;
	rqstp->rq_arg.head[0].iov_len -= hdr_len;

	*rdma_req = rmsgp;
	return hdr_len;
}

int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
{
	struct rpcrdma_msg *rmsgp = NULL;
	struct rpcrdma_read_chunk *ch;
	struct rpcrdma_write_array *ary;
	u32 *va;
	u32 hdrlen;

	dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
		rqstp);
	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;

	/* Pull in the extra for the padded case and bump our pointer */
	if (rmsgp->rm_type == RDMA_MSGP) {
		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
		rqstp->rq_arg.head[0].iov_base = va;
		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
		rqstp->rq_arg.head[0].iov_len -= hdrlen;
		return hdrlen;
	}

	/*
	 * Skip all chunks to find RPC msg. These were previously processed
	 */
	va = &rmsgp->rm_body.rm_chunks[0];

	/* Skip read-list */
	for (ch = (struct rpcrdma_read_chunk *)va;
	     ch->rc_discrim != xdr_zero; ch++);
	va = (u32 *)&ch->rc_position;

	/* Skip write-list */
	ary = (struct rpcrdma_write_array *)va;
	if (ary->wc_discrim == xdr_zero)
		va = (u32 *)&ary->wc_nchunks;
	else
		/*
		 * rs_length is the 2nd 4B field in wc_target and taking its
		 * address skips the list terminator
		 */
		va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;

	/* Skip reply-array */
	ary = (struct rpcrdma_write_array *)va;
	if (ary->wc_discrim == xdr_zero)
		va = (u32 *)&ary->wc_nchunks;
	else
		va = (u32 *)&ary->wc_array[ary->wc_nchunks];

	rqstp->rq_arg.head[0].iov_base = va;
	hdrlen = (unsigned long)va - (unsigned long)rmsgp;
	rqstp->rq_arg.head[0].iov_len -= hdrlen;

	return hdrlen;
}

int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
			      struct rpcrdma_msg *rmsgp,
			      enum rpcrdma_errcode err, u32 *va)
{
	u32 *startp = va;

	*va++ = htonl(rmsgp->rm_xid);
	*va++ = htonl(rmsgp->rm_vers);
	*va++ = htonl(xprt->sc_max_requests);
	*va++ = htonl(RDMA_ERROR);
	*va++ = htonl(err);
	if (err == ERR_VERS) {
		*va++ = htonl(RPCRDMA_VERSION);
		*va++ = htonl(RPCRDMA_VERSION);
	}

	return (int)((unsigned long)va - (unsigned long)startp);
}

int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
{
	struct rpcrdma_write_array *wr_ary;

	/* There is no read-list in a reply */

	/* skip write list */
	wr_ary = (struct rpcrdma_write_array *)
		&rmsgp->rm_body.rm_chunks[1];
	if (wr_ary->wc_discrim)
		wr_ary = (struct rpcrdma_write_array *)
			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
			wc_target.rs_length;
	else
		wr_ary = (struct rpcrdma_write_array *)
			&wr_ary->wc_nchunks;

	/* skip reply array */
	if (wr_ary->wc_discrim)
		wr_ary = (struct rpcrdma_write_array *)
			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
	else
		wr_ary = (struct rpcrdma_write_array *)
			&wr_ary->wc_nchunks;

	return (unsigned long) wr_ary - (unsigned long) rmsgp;
}

void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
{
	struct rpcrdma_write_array *ary;

	/* no read-list */
	rmsgp->rm_body.rm_chunks[0] = xdr_zero;

	/* write-array discrim */
	ary = (struct rpcrdma_write_array *)
		&rmsgp->rm_body.rm_chunks[1];
	ary->wc_discrim = xdr_one;
	ary->wc_nchunks = htonl(chunks);

	/* write-list terminator */
	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;

	/* reply-array discriminator */
	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
}

void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
				 int chunks)
{
	ary->wc_discrim = xdr_one;
	ary->wc_nchunks = htonl(chunks);
}

void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
				     int chunk_no,
				     __be32 rs_handle,
				     __be64 rs_offset,
				     u32 write_len)
{
	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
	seg->rs_handle = rs_handle;
	seg->rs_offset = rs_offset;
	seg->rs_length = htonl(write_len);
}

void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
				  struct rpcrdma_msg *rdma_argp,
				  struct rpcrdma_msg *rdma_resp,
				  enum rpcrdma_proc rdma_type)
{
	rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
	rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
	rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
	rdma_resp->rm_type = htonl(rdma_type);

	/* Encode <nul> chunks lists */
	rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
	rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
	rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
}
Commit	Line	Data
ef1eac0a TT	1	/*
	2	* Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
	3	*
	4	* This software is available to you under a choice of one of two
	5	* licenses. You may choose to be licensed under the terms of the GNU
	6	* General Public License (GPL) Version 2, available from the file
	7	* COPYING in the main directory of this source tree, or the BSD-type
	8	* license below:
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	*
	14	* Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions and the following disclaimer.
	16	*
	17	* Redistributions in binary form must reproduce the above
	18	* copyright notice, this list of conditions and the following
	19	* disclaimer in the documentation and/or other materials provided
	20	* with the distribution.
	21	*
	22	* Neither the name of the Network Appliance, Inc. nor the names of
	23	* its contributors may be used to endorse or promote products
	24	* derived from this software without specific prior written
	25	* permission.
	26	*
	27	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	28	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	29	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	30	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	31	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	32	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	33	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	34	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	35	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	36	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	37	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	38	*
	39	* Author: Tom Tucker <tom@opengridcomputing.com>
	40	*/
	41
	42	#include <linux/sunrpc/xdr.h>
	43	#include <linux/sunrpc/debug.h>
	44	#include <asm/unaligned.h>
	45	#include <linux/sunrpc/rpc_rdma.h>
	46	#include <linux/sunrpc/svc_rdma.h>
	47
	48	#define RPCDBG_FACILITY RPCDBG_SVCXPRT
	49
	50	/*
	51	* Decodes a read chunk list. The expected format is as follows:
	52	* descrim : xdr_one
	53	* position : u32 offset into XDR stream
	54	* handle : u32 RKEY
	55	* . . .
	56	* end-of-list: xdr_zero
	57	*/
	58	static u32 decode_read_list(u32 va, u32 *vaend)
	59	{
	60	struct rpcrdma_read_chunk ch = (struct rpcrdma_read_chunk )va;
	61
	62	while (ch->rc_discrim != xdr_zero) {
ef1eac0a TT	63	if (((unsigned long)ch + sizeof(struct rpcrdma_read_chunk)) >
	64	(unsigned long)vaend) {
	65	dprintk("svcrdma: vaend=%p, ch=%p\n", vaend, ch);
	66	return NULL;
	67	}
ef1eac0a TT	68	ch++;
	69	}
	70	return (u32 *)&ch->rc_position;
	71	}
	72
ef1eac0a TT	73	/*
	74	* Decodes a write chunk list. The expected format is as follows:
	75	* descrim : xdr_one
	76	* nchunks : <count>
	77	* handle : u32 RKEY ---+
	78	* length : u32 <len of segment> \|
	79	* offset : remove va + <count>
	80	* . . . \|
	81	* ---+
	82	*/
	83	static u32 decode_write_list(u32 va, u32 *vaend)
	84	{
b2781e10	85	unsigned long start, end;
cec56c8f TT	86	int nchunks;
cec56c8f TT	87
ef1eac0a TT	88	struct rpcrdma_write_array *ary =
	89	(struct rpcrdma_write_array *)va;
	90
	91	/* Check for not write-array */
	92	if (ary->wc_discrim == xdr_zero)
	93	return (u32 *)&ary->wc_nchunks;
	94
	95	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
	96	(unsigned long)vaend) {
	97	dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
	98	return NULL;
	99	}
cec56c8f	100	nchunks = ntohl(ary->wc_nchunks);
b2781e10 DC	101
	102	start = (unsigned long)&ary->wc_array[0];
	103	end = (unsigned long)vaend;
	104	if (nchunks < 0 \|\|
	105	nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) \|\|
	106	(start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
ef1eac0a	107	dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
cec56c8f	108	ary, nchunks, vaend);
ef1eac0a TT	109	return NULL;
ef1eac0a TT	110	}
ef1eac0a TT	111	/*
	112	* rs_length is the 2nd 4B field in wc_target and taking its
	113	* address skips the list terminator
	114	*/
cec56c8f	115	return (u32 *)&ary->wc_array[nchunks].wc_target.rs_length;
ef1eac0a TT	116	}
	117
	118	static u32 decode_reply_array(u32 va, u32 *vaend)
	119	{
b2781e10	120	unsigned long start, end;
cec56c8f	121	int nchunks;
ef1eac0a TT	122	struct rpcrdma_write_array *ary =
	123	(struct rpcrdma_write_array *)va;
	124
	125	/* Check for no reply-array */
	126	if (ary->wc_discrim == xdr_zero)
	127	return (u32 *)&ary->wc_nchunks;
	128
	129	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
	130	(unsigned long)vaend) {
	131	dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
	132	return NULL;
	133	}
cec56c8f	134	nchunks = ntohl(ary->wc_nchunks);
b2781e10 DC	135
	136	start = (unsigned long)&ary->wc_array[0];
	137	end = (unsigned long)vaend;
	138	if (nchunks < 0 \|\|
	139	nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) \|\|
	140	(start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
ef1eac0a	141	dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
cec56c8f	142	ary, nchunks, vaend);
ef1eac0a TT	143	return NULL;
ef1eac0a TT	144	}
cec56c8f	145	return (u32 *)&ary->wc_array[nchunks];
ef1eac0a TT	146	}
	147
	148	int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
	149	struct svc_rqst *rqstp)
	150	{
	151	struct rpcrdma_msg *rmsgp = NULL;
	152	u32 *va;
	153	u32 *vaend;
	154	u32 hdr_len;
	155
	156	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
	157
	158	/* Verify that there's enough bytes for header + something */
	159	if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
	160	dprintk("svcrdma: header too short = %d\n",
	161	rqstp->rq_arg.len);
	162	return -EINVAL;
	163	}
	164
	165	/* Decode the header */
	166	rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
	167	rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
	168	rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
	169	rmsgp->rm_type = ntohl(rmsgp->rm_type);
	170
	171	if (rmsgp->rm_vers != RPCRDMA_VERSION)
	172	return -ENOSYS;
	173
	174	/* Pull in the extra for the padded case and bump our pointer */
	175	if (rmsgp->rm_type == RDMA_MSGP) {
	176	int hdrlen;
	177	rmsgp->rm_body.rm_padded.rm_align =
	178	ntohl(rmsgp->rm_body.rm_padded.rm_align);
	179	rmsgp->rm_body.rm_padded.rm_thresh =
	180	ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
	181
	182	va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
	183	rqstp->rq_arg.head[0].iov_base = va;
	184	hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
	185	rqstp->rq_arg.head[0].iov_len -= hdrlen;
	186	if (hdrlen > rqstp->rq_arg.len)
	187	return -EINVAL;
	188	return hdrlen;
	189	}
	190
	191	/* The chunk list may contain either a read chunk list or a write
	192	* chunk list and a reply chunk list.
	193	*/
	194	va = &rmsgp->rm_body.rm_chunks[0];
	195	vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
	196	va = decode_read_list(va, vaend);
	197	if (!va)
	198	return -EINVAL;
	199	va = decode_write_list(va, vaend);
	200	if (!va)
	201	return -EINVAL;
	202	va = decode_reply_array(va, vaend);
	203	if (!va)
	204	return -EINVAL;
	205
	206	rqstp->rq_arg.head[0].iov_base = va;
	207	hdr_len = (unsigned long)va - (unsigned long)rmsgp;
	208	rqstp->rq_arg.head[0].iov_len -= hdr_len;
	209
210	*rdma_req = rmsgp;
211	return hdr_len;
212	}
213
214	int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
215	{
216	struct rpcrdma_msg *rmsgp = NULL;
217	struct rpcrdma_read_chunk *ch;
218	struct rpcrdma_write_array *ary;
219	u32 *va;
220	u32 hdrlen;
221
222	dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
223	rqstp);
224	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
225
226	/* Pull in the extra for the padded case and bump our pointer */
227	if (rmsgp->rm_type == RDMA_MSGP) {
228	va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
229	rqstp->rq_arg.head[0].iov_base = va;
230	hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
231	rqstp->rq_arg.head[0].iov_len -= hdrlen;
232	return hdrlen;
233	}
234
235	/*
236	* Skip all chunks to find RPC msg. These were previously processed
237	*/
238	va = &rmsgp->rm_body.rm_chunks[0];
239
240	/* Skip read-list */
241	for (ch = (struct rpcrdma_read_chunk *)va;
242	ch->rc_discrim != xdr_zero; ch++);
243	va = (u32 *)&ch->rc_position;
244
245	/* Skip write-list */
246	ary = (struct rpcrdma_write_array *)va;
247	if (ary->wc_discrim == xdr_zero)
248	va = (u32 *)&ary->wc_nchunks;
249	else
250	/*
251	* rs_length is the 2nd 4B field in wc_target and taking its
252	* address skips the list terminator
253	*/
254	va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
255
256	/* Skip reply-array */
257	ary = (struct rpcrdma_write_array *)va;
258	if (ary->wc_discrim == xdr_zero)
259	va = (u32 *)&ary->wc_nchunks;
260	else
261	va = (u32 *)&ary->wc_array[ary->wc_nchunks];
262
263	rqstp->rq_arg.head[0].iov_base = va;
264	hdrlen = (unsigned long)va - (unsigned long)rmsgp;
265	rqstp->rq_arg.head[0].iov_len -= hdrlen;
266
267	return hdrlen;
268	}
269
270	int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
271	struct rpcrdma_msg *rmsgp,
272	enum rpcrdma_errcode err, u32 *va)
273	{
274	u32 *startp = va;
275
276	*va++ = htonl(rmsgp->rm_xid);
277	*va++ = htonl(rmsgp->rm_vers);
278	*va++ = htonl(xprt->sc_max_requests);
279	*va++ = htonl(RDMA_ERROR);
280	*va++ = htonl(err);
281	if (err == ERR_VERS) {
282	*va++ = htonl(RPCRDMA_VERSION);
283	*va++ = htonl(RPCRDMA_VERSION);
284	}
285
286	return (int)((unsigned long)va - (unsigned long)startp);
287	}
288
289	int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
290	{
291	struct rpcrdma_write_array *wr_ary;
292
293	/* There is no read-list in a reply */
294
295	/* skip write list */
296	wr_ary = (struct rpcrdma_write_array *)
297	&rmsgp->rm_body.rm_chunks[1];
298	if (wr_ary->wc_discrim)
299	wr_ary = (struct rpcrdma_write_array *)
300	&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
301	wc_target.rs_length;
302	else
303	wr_ary = (struct rpcrdma_write_array *)
304	&wr_ary->wc_nchunks;
305
306	/* skip reply array */
307	if (wr_ary->wc_discrim)
308	wr_ary = (struct rpcrdma_write_array *)
309	&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
310	else
311	wr_ary = (struct rpcrdma_write_array *)
312	&wr_ary->wc_nchunks;
313
314	return (unsigned long) wr_ary - (unsigned long) rmsgp;
315	}
316
317	void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
318	{
319	struct rpcrdma_write_array *ary;
320
321	/* no read-list */
322	rmsgp->rm_body.rm_chunks[0] = xdr_zero;
323
324	/* write-array discrim */
325	ary = (struct rpcrdma_write_array *)
326	&rmsgp->rm_body.rm_chunks[1];
327	ary->wc_discrim = xdr_one;
328	ary->wc_nchunks = htonl(chunks);
329
330	/* write-list terminator */
331	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
332
333	/* reply-array discriminator */
334	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
335	}
336
337	void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
338	int chunks)
339	{
340	ary->wc_discrim = xdr_one;
341	ary->wc_nchunks = htonl(chunks);
342	}
343
344	void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
345	int chunk_no,
cec56c8f TT	346	__be32 rs_handle,
cec56c8f TT	347	__be64 rs_offset,
ef1eac0a TT	348	u32 write_len)
	349	{
	350	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
cec56c8f TT	351	seg->rs_handle = rs_handle;
cec56c8f TT	352	seg->rs_offset = rs_offset;
ef1eac0a	353	seg->rs_length = htonl(write_len);
ef1eac0a TT	354	}
	355
	356	void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
	357	struct rpcrdma_msg *rdma_argp,
	358	struct rpcrdma_msg *rdma_resp,
	359	enum rpcrdma_proc rdma_type)
	360	{
	361	rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
	362	rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
	363	rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
	364	rdma_resp->rm_type = htonl(rdma_type);
	365
	366	/* Encode <nul> chunks lists */
	367	rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
	368	rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
	369	rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
	370	}