98fc21d3bf
Replace C structure-based XDR decoding with pointer arithmetic. Pointer arithmetic is considered more portable, and is used throughout the kernel's existing XDR encoders. The gcc optimizer generates similar assembler code either way. Byte-swapping before a memory store on x86 typically results in an instruction pipeline stall. Avoid byte-swapping when encoding a new header. svcrdma currently doesn't alter a connection's credit grant value after the connection has been accepted, so it is effectively a constant. Cache the byte-swapped value in a separate field. Christoph suggested pulling the header encoding logic into the only function that uses it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
332 lines
9.5 KiB
C
332 lines
9.5 KiB
C
/*
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* Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the BSD-type
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* license below:
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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*
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* Neither the name of the Network Appliance, Inc. nor the names of
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* its contributors may be used to endorse or promote products
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* derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* Author: Tom Tucker <tom@opengridcomputing.com>
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*/
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#include <linux/sunrpc/xdr.h>
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#include <linux/sunrpc/debug.h>
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#include <asm/unaligned.h>
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#include <linux/sunrpc/rpc_rdma.h>
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#include <linux/sunrpc/svc_rdma.h>
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#define RPCDBG_FACILITY RPCDBG_SVCXPRT
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/*
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* Decodes a read chunk list. The expected format is as follows:
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* descrim : xdr_one
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* position : __be32 offset into XDR stream
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* handle : __be32 RKEY
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* . . .
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* end-of-list: xdr_zero
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*/
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static __be32 *decode_read_list(__be32 *va, __be32 *vaend)
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{
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struct rpcrdma_read_chunk *ch = (struct rpcrdma_read_chunk *)va;
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while (ch->rc_discrim != xdr_zero) {
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if (((unsigned long)ch + sizeof(struct rpcrdma_read_chunk)) >
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(unsigned long)vaend) {
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dprintk("svcrdma: vaend=%p, ch=%p\n", vaend, ch);
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return NULL;
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}
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ch++;
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}
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return &ch->rc_position;
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}
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/*
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* Decodes a write chunk list. The expected format is as follows:
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* descrim : xdr_one
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* nchunks : <count>
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* handle : __be32 RKEY ---+
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* length : __be32 <len of segment> |
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* offset : remove va + <count>
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* . . . |
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* ---+
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*/
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static __be32 *decode_write_list(__be32 *va, __be32 *vaend)
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{
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unsigned long start, end;
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int nchunks;
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struct rpcrdma_write_array *ary =
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(struct rpcrdma_write_array *)va;
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/* Check for not write-array */
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if (ary->wc_discrim == xdr_zero)
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return &ary->wc_nchunks;
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if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
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(unsigned long)vaend) {
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dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
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return NULL;
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}
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nchunks = be32_to_cpu(ary->wc_nchunks);
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start = (unsigned long)&ary->wc_array[0];
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end = (unsigned long)vaend;
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if (nchunks < 0 ||
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nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
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(start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
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dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
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ary, nchunks, vaend);
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return NULL;
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}
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/*
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* rs_length is the 2nd 4B field in wc_target and taking its
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* address skips the list terminator
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*/
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return &ary->wc_array[nchunks].wc_target.rs_length;
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}
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static __be32 *decode_reply_array(__be32 *va, __be32 *vaend)
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{
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unsigned long start, end;
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int nchunks;
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struct rpcrdma_write_array *ary =
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(struct rpcrdma_write_array *)va;
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/* Check for no reply-array */
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if (ary->wc_discrim == xdr_zero)
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return &ary->wc_nchunks;
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if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
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(unsigned long)vaend) {
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dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
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return NULL;
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}
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nchunks = be32_to_cpu(ary->wc_nchunks);
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start = (unsigned long)&ary->wc_array[0];
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end = (unsigned long)vaend;
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if (nchunks < 0 ||
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nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
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(start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
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dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
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ary, nchunks, vaend);
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return NULL;
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}
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return (__be32 *)&ary->wc_array[nchunks];
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}
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/**
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* svc_rdma_xdr_decode_req - Parse incoming RPC-over-RDMA header
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* @rq_arg: Receive buffer
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*
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* On entry, xdr->head[0].iov_base points to first byte in the
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* RPC-over-RDMA header.
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*
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* On successful exit, head[0] points to first byte past the
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* RPC-over-RDMA header. For RDMA_MSG, this is the RPC message.
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* The length of the RPC-over-RDMA header is returned.
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*/
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int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg)
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{
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struct rpcrdma_msg *rmsgp;
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__be32 *va, *vaend;
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unsigned int len;
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u32 hdr_len;
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/* Verify that there's enough bytes for header + something */
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if (rq_arg->len <= RPCRDMA_HDRLEN_ERR) {
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dprintk("svcrdma: header too short = %d\n",
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rq_arg->len);
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return -EINVAL;
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}
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rmsgp = (struct rpcrdma_msg *)rq_arg->head[0].iov_base;
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if (rmsgp->rm_vers != rpcrdma_version) {
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dprintk("%s: bad version %u\n", __func__,
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be32_to_cpu(rmsgp->rm_vers));
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return -EPROTONOSUPPORT;
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}
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switch (be32_to_cpu(rmsgp->rm_type)) {
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case RDMA_MSG:
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case RDMA_NOMSG:
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break;
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case RDMA_DONE:
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/* Just drop it */
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dprintk("svcrdma: dropping RDMA_DONE message\n");
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return 0;
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case RDMA_ERROR:
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/* Possible if this is a backchannel reply.
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* XXX: We should cancel this XID, though.
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*/
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dprintk("svcrdma: dropping RDMA_ERROR message\n");
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return 0;
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case RDMA_MSGP:
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/* Pull in the extra for the padded case, bump our pointer */
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rmsgp->rm_body.rm_padded.rm_align =
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be32_to_cpu(rmsgp->rm_body.rm_padded.rm_align);
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rmsgp->rm_body.rm_padded.rm_thresh =
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be32_to_cpu(rmsgp->rm_body.rm_padded.rm_thresh);
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va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
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rq_arg->head[0].iov_base = va;
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len = (u32)((unsigned long)va - (unsigned long)rmsgp);
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rq_arg->head[0].iov_len -= len;
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if (len > rq_arg->len)
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return -EINVAL;
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return len;
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default:
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dprintk("svcrdma: bad rdma procedure (%u)\n",
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be32_to_cpu(rmsgp->rm_type));
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return -EINVAL;
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}
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/* The chunk list may contain either a read chunk list or a write
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* chunk list and a reply chunk list.
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*/
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va = &rmsgp->rm_body.rm_chunks[0];
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vaend = (__be32 *)((unsigned long)rmsgp + rq_arg->len);
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va = decode_read_list(va, vaend);
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if (!va) {
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dprintk("svcrdma: failed to decode read list\n");
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return -EINVAL;
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}
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va = decode_write_list(va, vaend);
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if (!va) {
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dprintk("svcrdma: failed to decode write list\n");
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return -EINVAL;
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}
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va = decode_reply_array(va, vaend);
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if (!va) {
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dprintk("svcrdma: failed to decode reply chunk\n");
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return -EINVAL;
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}
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rq_arg->head[0].iov_base = va;
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hdr_len = (unsigned long)va - (unsigned long)rmsgp;
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rq_arg->head[0].iov_len -= hdr_len;
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return hdr_len;
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}
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int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
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struct rpcrdma_msg *rmsgp,
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enum rpcrdma_errcode err, __be32 *va)
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{
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__be32 *startp = va;
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*va++ = rmsgp->rm_xid;
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*va++ = rmsgp->rm_vers;
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*va++ = xprt->sc_fc_credits;
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*va++ = rdma_error;
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*va++ = cpu_to_be32(err);
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if (err == ERR_VERS) {
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*va++ = rpcrdma_version;
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*va++ = rpcrdma_version;
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}
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return (int)((unsigned long)va - (unsigned long)startp);
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}
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/**
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* svc_rdma_xdr_get_reply_hdr_length - Get length of Reply transport header
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* @rdma_resp: buffer containing Reply transport header
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*
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* Returns length of transport header, in bytes.
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*/
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unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp)
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{
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unsigned int nsegs;
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__be32 *p;
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p = rdma_resp;
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/* RPC-over-RDMA V1 replies never have a Read list. */
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p += rpcrdma_fixed_maxsz + 1;
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/* Skip Write list. */
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while (*p++ != xdr_zero) {
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nsegs = be32_to_cpup(p++);
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p += nsegs * rpcrdma_segment_maxsz;
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}
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/* Skip Reply chunk. */
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if (*p++ != xdr_zero) {
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nsegs = be32_to_cpup(p++);
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p += nsegs * rpcrdma_segment_maxsz;
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}
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return (unsigned long)p - (unsigned long)rdma_resp;
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}
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void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
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{
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struct rpcrdma_write_array *ary;
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/* no read-list */
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rmsgp->rm_body.rm_chunks[0] = xdr_zero;
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/* write-array discrim */
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ary = (struct rpcrdma_write_array *)
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&rmsgp->rm_body.rm_chunks[1];
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ary->wc_discrim = xdr_one;
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ary->wc_nchunks = cpu_to_be32(chunks);
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/* write-list terminator */
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ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
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/* reply-array discriminator */
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ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
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}
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void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
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int chunks)
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{
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ary->wc_discrim = xdr_one;
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ary->wc_nchunks = cpu_to_be32(chunks);
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}
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void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
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int chunk_no,
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__be32 rs_handle,
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__be64 rs_offset,
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u32 write_len)
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{
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struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
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seg->rs_handle = rs_handle;
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seg->rs_offset = rs_offset;
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seg->rs_length = cpu_to_be32(write_len);
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}
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