[GitHub/moto-9609/android_kernel_motorola_exynos9610.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;
}

/*
 * Determine number of chunks and total bytes in chunk list. The chunk
 * list has already been verified to fit within the RPCRDMA header.
 */
void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch,
			       int *ch_count, int *byte_count)
{
	/* compute the number of bytes represented by read chunks */
	*byte_count = 0;
	*ch_count = 0;
	for (; ch->rc_discrim != 0; ch++) {
		*byte_count = *byte_count + ntohl(ch->rc_target.rs_length);
		*ch_count = *ch_count + 1;
	}
}

/*
 * 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)
{
	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);
	if (((unsigned long)&ary->wc_array[0] +
	     (sizeof(struct rpcrdma_write_chunk) * nchunks)) >
	    (unsigned long)vaend) {
		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)
{
	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);
	if (((unsigned long)&ary->wc_array[0] +
	     (sizeof(struct rpcrdma_write_chunk) * nchunks)) >
	    (unsigned long)vaend) {
		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
	73	/*
	74	* Determine number of chunks and total bytes in chunk list. The chunk
	75	* list has already been verified to fit within the RPCRDMA header.
	76	*/
	77	void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch,
	78	int ch_count, int byte_count)
	79	{
	80	/* compute the number of bytes represented by read chunks */
	81	*byte_count = 0;
	82	*ch_count = 0;
	83	for (; ch->rc_discrim != 0; ch++) {
cec56c8f	84	byte_count = byte_count + ntohl(ch->rc_target.rs_length);
ef1eac0a TT	85	ch_count = ch_count + 1;
	86	}
	87	}
	88
	89	/*
	90	* Decodes a write chunk list. The expected format is as follows:
	91	* descrim : xdr_one
	92	* nchunks : <count>
	93	* handle : u32 RKEY ---+
	94	* length : u32 <len of segment> \|
	95	* offset : remove va + <count>
	96	* . . . \|
	97	* ---+
	98	*/
	99	static u32 decode_write_list(u32 va, u32 *vaend)
	100	{
cec56c8f TT	101	int nchunks;
cec56c8f TT	102
ef1eac0a TT	103	struct rpcrdma_write_array *ary =
	104	(struct rpcrdma_write_array *)va;
	105
	106	/* Check for not write-array */
	107	if (ary->wc_discrim == xdr_zero)
	108	return (u32 *)&ary->wc_nchunks;
	109
	110	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
	111	(unsigned long)vaend) {
	112	dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
	113	return NULL;
	114	}
cec56c8f	115	nchunks = ntohl(ary->wc_nchunks);
ef1eac0a	116	if (((unsigned long)&ary->wc_array[0] +
cec56c8f	117	(sizeof(struct rpcrdma_write_chunk) * nchunks)) >
ef1eac0a TT	118	(unsigned long)vaend) {
ef1eac0a TT	119	dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
cec56c8f	120	ary, nchunks, vaend);
ef1eac0a TT	121	return NULL;
ef1eac0a TT	122	}
ef1eac0a TT	123	/*
	124	* rs_length is the 2nd 4B field in wc_target and taking its
	125	* address skips the list terminator
	126	*/
cec56c8f	127	return (u32 *)&ary->wc_array[nchunks].wc_target.rs_length;
ef1eac0a TT	128	}
	129
	130	static u32 decode_reply_array(u32 va, u32 *vaend)
	131	{
cec56c8f	132	int nchunks;
ef1eac0a TT	133	struct rpcrdma_write_array *ary =
	134	(struct rpcrdma_write_array *)va;
	135
	136	/* Check for no reply-array */
	137	if (ary->wc_discrim == xdr_zero)
	138	return (u32 *)&ary->wc_nchunks;
	139
	140	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
	141	(unsigned long)vaend) {
	142	dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
	143	return NULL;
	144	}
cec56c8f	145	nchunks = ntohl(ary->wc_nchunks);
ef1eac0a	146	if (((unsigned long)&ary->wc_array[0] +
cec56c8f	147	(sizeof(struct rpcrdma_write_chunk) * nchunks)) >
ef1eac0a TT	148	(unsigned long)vaend) {
ef1eac0a TT	149	dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
cec56c8f	150	ary, nchunks, vaend);
ef1eac0a TT	151	return NULL;
ef1eac0a TT	152	}
cec56c8f	153	return (u32 *)&ary->wc_array[nchunks];
ef1eac0a TT	154	}
	155
	156	int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
	157	struct svc_rqst *rqstp)
	158	{
	159	struct rpcrdma_msg *rmsgp = NULL;
	160	u32 *va;
	161	u32 *vaend;
	162	u32 hdr_len;
	163
	164	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
	165
	166	/* Verify that there's enough bytes for header + something */
	167	if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
	168	dprintk("svcrdma: header too short = %d\n",
	169	rqstp->rq_arg.len);
	170	return -EINVAL;
	171	}
	172
	173	/* Decode the header */
	174	rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
	175	rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
	176	rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
	177	rmsgp->rm_type = ntohl(rmsgp->rm_type);
	178
	179	if (rmsgp->rm_vers != RPCRDMA_VERSION)
	180	return -ENOSYS;
	181
	182	/* Pull in the extra for the padded case and bump our pointer */
	183	if (rmsgp->rm_type == RDMA_MSGP) {
	184	int hdrlen;
	185	rmsgp->rm_body.rm_padded.rm_align =
	186	ntohl(rmsgp->rm_body.rm_padded.rm_align);
	187	rmsgp->rm_body.rm_padded.rm_thresh =
	188	ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
	189
	190	va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
	191	rqstp->rq_arg.head[0].iov_base = va;
	192	hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
	193	rqstp->rq_arg.head[0].iov_len -= hdrlen;
	194	if (hdrlen > rqstp->rq_arg.len)
	195	return -EINVAL;
	196	return hdrlen;
	197	}
	198
	199	/* The chunk list may contain either a read chunk list or a write
	200	* chunk list and a reply chunk list.
	201	*/
	202	va = &rmsgp->rm_body.rm_chunks[0];
	203	vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
	204	va = decode_read_list(va, vaend);
	205	if (!va)
	206	return -EINVAL;
	207	va = decode_write_list(va, vaend);
	208	if (!va)
	209	return -EINVAL;
	210	va = decode_reply_array(va, vaend);
	211	if (!va)
	212	return -EINVAL;
	213
	214	rqstp->rq_arg.head[0].iov_base = va;
	215	hdr_len = (unsigned long)va - (unsigned long)rmsgp;
	216	rqstp->rq_arg.head[0].iov_len -= hdr_len;
	217
218	*rdma_req = rmsgp;
219	return hdr_len;
220	}
221
222	int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
223	{
224	struct rpcrdma_msg *rmsgp = NULL;
225	struct rpcrdma_read_chunk *ch;
226	struct rpcrdma_write_array *ary;
227	u32 *va;
228	u32 hdrlen;
229
230	dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
231	rqstp);
232	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
233
234	/* Pull in the extra for the padded case and bump our pointer */
235	if (rmsgp->rm_type == RDMA_MSGP) {
236	va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
237	rqstp->rq_arg.head[0].iov_base = va;
238	hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
239	rqstp->rq_arg.head[0].iov_len -= hdrlen;
240	return hdrlen;
241	}
242
243	/*
244	* Skip all chunks to find RPC msg. These were previously processed
245	*/
246	va = &rmsgp->rm_body.rm_chunks[0];
247
248	/* Skip read-list */
249	for (ch = (struct rpcrdma_read_chunk *)va;
250	ch->rc_discrim != xdr_zero; ch++);
251	va = (u32 *)&ch->rc_position;
252
253	/* Skip write-list */
254	ary = (struct rpcrdma_write_array *)va;
255	if (ary->wc_discrim == xdr_zero)
256	va = (u32 *)&ary->wc_nchunks;
257	else
258	/*
259	* rs_length is the 2nd 4B field in wc_target and taking its
260	* address skips the list terminator
261	*/
262	va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
263
264	/* Skip reply-array */
265	ary = (struct rpcrdma_write_array *)va;
266	if (ary->wc_discrim == xdr_zero)
267	va = (u32 *)&ary->wc_nchunks;
268	else
269	va = (u32 *)&ary->wc_array[ary->wc_nchunks];
270
271	rqstp->rq_arg.head[0].iov_base = va;
272	hdrlen = (unsigned long)va - (unsigned long)rmsgp;
273	rqstp->rq_arg.head[0].iov_len -= hdrlen;
274
275	return hdrlen;
276	}
277
278	int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
279	struct rpcrdma_msg *rmsgp,
280	enum rpcrdma_errcode err, u32 *va)
281	{
282	u32 *startp = va;
283
284	*va++ = htonl(rmsgp->rm_xid);
285	*va++ = htonl(rmsgp->rm_vers);
286	*va++ = htonl(xprt->sc_max_requests);
287	*va++ = htonl(RDMA_ERROR);
288	*va++ = htonl(err);
289	if (err == ERR_VERS) {
290	*va++ = htonl(RPCRDMA_VERSION);
291	*va++ = htonl(RPCRDMA_VERSION);
292	}
293
294	return (int)((unsigned long)va - (unsigned long)startp);
295	}
296
297	int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
298	{
299	struct rpcrdma_write_array *wr_ary;
300
301	/* There is no read-list in a reply */
302
303	/* skip write list */
304	wr_ary = (struct rpcrdma_write_array *)
305	&rmsgp->rm_body.rm_chunks[1];
306	if (wr_ary->wc_discrim)
307	wr_ary = (struct rpcrdma_write_array *)
308	&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
309	wc_target.rs_length;
310	else
311	wr_ary = (struct rpcrdma_write_array *)
312	&wr_ary->wc_nchunks;
313
314	/* skip reply array */
315	if (wr_ary->wc_discrim)
316	wr_ary = (struct rpcrdma_write_array *)
317	&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
318	else
319	wr_ary = (struct rpcrdma_write_array *)
320	&wr_ary->wc_nchunks;
321
322	return (unsigned long) wr_ary - (unsigned long) rmsgp;
323	}
324
325	void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
326	{
327	struct rpcrdma_write_array *ary;
328
329	/* no read-list */
330	rmsgp->rm_body.rm_chunks[0] = xdr_zero;
331
332	/* write-array discrim */
333	ary = (struct rpcrdma_write_array *)
334	&rmsgp->rm_body.rm_chunks[1];
335	ary->wc_discrim = xdr_one;
336	ary->wc_nchunks = htonl(chunks);
337
338	/* write-list terminator */
339	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
340
341	/* reply-array discriminator */
342	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
343	}
344
345	void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
346	int chunks)
347	{
348	ary->wc_discrim = xdr_one;
349	ary->wc_nchunks = htonl(chunks);
350	}
351
352	void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
353	int chunk_no,
cec56c8f TT	354	__be32 rs_handle,
cec56c8f TT	355	__be64 rs_offset,
ef1eac0a TT	356	u32 write_len)
	357	{
	358	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
cec56c8f TT	359	seg->rs_handle = rs_handle;
cec56c8f TT	360	seg->rs_offset = rs_offset;
ef1eac0a	361	seg->rs_length = htonl(write_len);
ef1eac0a TT	362	}
	363
	364	void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
	365	struct rpcrdma_msg *rdma_argp,
	366	struct rpcrdma_msg *rdma_resp,
	367	enum rpcrdma_proc rdma_type)
	368	{
	369	rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
	370	rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
	371	rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
	372	rdma_resp->rm_type = htonl(rdma_type);
	373
	374	/* Encode <nul> chunks lists */
	375	rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
	376	rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
	377	rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
	378	}