/* * 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 */ #include #include #include #include #include #include #include #define RPCDBG_FACILITY RPCDBG_SVCXPRT /* * Replace the pages in the rq_argpages array with the pages from the SGE in * the RDMA_RECV completion. The SGL should contain full pages up until the * last one. */ static void rdma_build_arg_xdr(struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *ctxt, u32 byte_count) { struct page *page; u32 bc; int sge_no; /* Swap the page in the SGE with the page in argpages */ page = ctxt->pages[0]; put_page(rqstp->rq_pages[0]); rqstp->rq_pages[0] = page; /* Set up the XDR head */ rqstp->rq_arg.head[0].iov_base = page_address(page); rqstp->rq_arg.head[0].iov_len = min(byte_count, ctxt->sge[0].length); rqstp->rq_arg.len = byte_count; rqstp->rq_arg.buflen = byte_count; /* Compute bytes past head in the SGL */ bc = byte_count - rqstp->rq_arg.head[0].iov_len; /* If data remains, store it in the pagelist */ rqstp->rq_arg.page_len = bc; rqstp->rq_arg.page_base = 0; rqstp->rq_arg.pages = &rqstp->rq_pages[1]; sge_no = 1; while (bc && sge_no < ctxt->count) { page = ctxt->pages[sge_no]; put_page(rqstp->rq_pages[sge_no]); rqstp->rq_pages[sge_no] = page; bc -= min(bc, ctxt->sge[sge_no].length); rqstp->rq_arg.buflen += ctxt->sge[sge_no].length; sge_no++; } rqstp->rq_respages = &rqstp->rq_pages[sge_no]; /* We should never run out of SGE because the limit is defined to * support the max allowed RPC data length */ BUG_ON(bc && (sge_no == ctxt->count)); BUG_ON((rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len) != byte_count); BUG_ON(rqstp->rq_arg.len != byte_count); /* If not all pages were used from the SGL, free the remaining ones */ bc = sge_no; while (sge_no < ctxt->count) { page = ctxt->pages[sge_no++]; put_page(page); } ctxt->count = bc; /* Set up tail */ rqstp->rq_arg.tail[0].iov_base = NULL; rqstp->rq_arg.tail[0].iov_len = 0; } struct chunk_sge { int start; /* sge no for this chunk */ int count; /* sge count for this chunk */ }; /* Encode a read-chunk-list as an array of IB SGE * * Assumptions: * - chunk[0]->position points to pages[0] at an offset of 0 * - pages[] is not physically or virtually contigous and consists of * PAGE_SIZE elements. * * Output: * - sge array pointing into pages[] array. * - chunk_sge array specifying sge index and count for each * chunk in the read list * */ static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head, struct rpcrdma_msg *rmsgp, struct ib_sge *sge, struct chunk_sge *ch_sge_ary, int ch_count, int byte_count) { int sge_no; int sge_bytes; int page_off; int page_no; int ch_bytes; int ch_no; struct rpcrdma_read_chunk *ch; sge_no = 0; page_no = 0; page_off = 0; ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; ch_no = 0; ch_bytes = ch->rc_target.rs_length; head->arg.head[0] = rqstp->rq_arg.head[0]; head->arg.tail[0] = rqstp->rq_arg.tail[0]; head->arg.pages = &head->pages[head->count]; head->sge[0].length = head->count; /* save count of hdr pages */ head->arg.page_base = 0; head->arg.page_len = ch_bytes; head->arg.len = rqstp->rq_arg.len + ch_bytes; head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes; head->count++; ch_sge_ary[0].start = 0; while (byte_count) { sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes); sge[sge_no].addr = ib_dma_map_page(xprt->sc_cm_id->device, rqstp->rq_arg.pages[page_no], page_off, sge_bytes, DMA_FROM_DEVICE); sge[sge_no].length = sge_bytes; sge[sge_no].lkey = xprt->sc_phys_mr->lkey; /* * Don't bump head->count here because the same page * may be used by multiple SGE. */ head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no]; rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1]; byte_count -= sge_bytes; ch_bytes -= sge_bytes; sge_no++; /* * If all bytes for this chunk have been mapped to an * SGE, move to the next SGE */ if (ch_bytes == 0) { ch_sge_ary[ch_no].count = sge_no - ch_sge_ary[ch_no].start; ch_no++; ch++; ch_sge_ary[ch_no].start = sge_no; ch_bytes = ch->rc_target.rs_length; /* If bytes remaining account for next chunk */ if (byte_count) { head->arg.page_len += ch_bytes; head->arg.len += ch_bytes; head->arg.buflen += ch_bytes; } } /* * If this SGE consumed all of the page, move to the * next page */ if ((sge_bytes + page_off) == PAGE_SIZE) { page_no++; page_off = 0; /* * If there are still bytes left to map, bump * the page count */ if (byte_count) head->count++; } else page_off += sge_bytes; } BUG_ON(byte_count != 0); return sge_no; } static void rdma_set_ctxt_sge(struct svc_rdma_op_ctxt *ctxt, struct ib_sge *sge, u64 *sgl_offset, int count) { int i; ctxt->count = count; for (i = 0; i < count; i++) { ctxt->sge[i].addr = sge[i].addr; ctxt->sge[i].length = sge[i].length; *sgl_offset = *sgl_offset + sge[i].length; } } static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) { if ((RDMA_TRANSPORT_IWARP == rdma_node_get_transport(xprt->sc_cm_id-> device->node_type)) && sge_count > 1) return 1; else return min_t(int, sge_count, xprt->sc_max_sge); } /* * Use RDMA_READ to read data from the advertised client buffer into the * XDR stream starting at rq_arg.head[0].iov_base. * Each chunk in the array * contains the following fields: * discrim - '1', This isn't used for data placement * position - The xdr stream offset (the same for every chunk) * handle - RMR for client memory region * length - data transfer length * offset - 64 bit tagged offset in remote memory region * * On our side, we need to read into a pagelist. The first page immediately * follows the RPC header. * * This function returns: * 0 - No error and no read-list found. * * 1 - Successful read-list processing. The data is not yet in * the pagelist and therefore the RPC request must be deferred. The * I/O completion will enqueue the transport again and * svc_rdma_recvfrom will complete the request. * * <0 - Error processing/posting read-list. * * NOTE: The ctxt must not be touched after the last WR has been posted * because the I/O completion processing may occur on another * processor and free / modify the context. Ne touche pas! */ static int rdma_read_xdr(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp, struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *hdr_ctxt) { struct ib_send_wr read_wr; int err = 0; int ch_no; struct ib_sge *sge; int ch_count; int byte_count; int sge_count; u64 sgl_offset; struct rpcrdma_read_chunk *ch; struct svc_rdma_op_ctxt *ctxt = NULL; struct svc_rdma_op_ctxt *tmp_sge_ctxt; struct svc_rdma_op_ctxt *tmp_ch_ctxt; struct chunk_sge *ch_sge_ary; /* If no read list is present, return 0 */ ch = svc_rdma_get_read_chunk(rmsgp); if (!ch) return 0; /* Allocate temporary contexts to keep SGE */ BUG_ON(sizeof(struct ib_sge) < sizeof(struct chunk_sge)); tmp_sge_ctxt = svc_rdma_get_context(xprt); sge = tmp_sge_ctxt->sge; tmp_ch_ctxt = svc_rdma_get_context(xprt); ch_sge_ary = (struct chunk_sge *)tmp_ch_ctxt->sge; svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count); sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp, sge, ch_sge_ary, ch_count, byte_count); sgl_offset = 0; ch_no = 0; for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; ch->rc_discrim != 0; ch++, ch_no++) { next_sge: ctxt = svc_rdma_get_context(xprt); ctxt->direction = DMA_FROM_DEVICE; clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); /* Prepare READ WR */ memset(&read_wr, 0, sizeof read_wr); ctxt->wr_op = IB_WR_RDMA_READ; read_wr.wr_id = (unsigned long)ctxt; read_wr.opcode = IB_WR_RDMA_READ; read_wr.send_flags = IB_SEND_SIGNALED; read_wr.wr.rdma.rkey = ch->rc_target.rs_handle; read_wr.wr.rdma.remote_addr = get_unaligned(&(ch->rc_target.rs_offset)) + sgl_offset; read_wr.sg_list = &sge[ch_sge_ary[ch_no].start]; read_wr.num_sge = rdma_read_max_sge(xprt, ch_sge_ary[ch_no].count); rdma_set_ctxt_sge(ctxt, &sge[ch_sge_ary[ch_no].start], &sgl_offset, read_wr.num_sge); if (((ch+1)->rc_discrim == 0) && (read_wr.num_sge == ch_sge_ary[ch_no].count)) { /* * Mark the last RDMA_READ with a bit to * indicate all RPC data has been fetched from * the client and the RPC needs to be enqueued. */ set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); ctxt->read_hdr = hdr_ctxt; } /* Post the read */ err = svc_rdma_send(xprt, &read_wr); if (err) { printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n", err); set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); svc_rdma_put_context(ctxt, 0); goto out; } atomic_inc(&rdma_stat_read); if (read_wr.num_sge < ch_sge_ary[ch_no].count) { ch_sge_ary[ch_no].count -= read_wr.num_sge; ch_sge_ary[ch_no].start += read_wr.num_sge; goto next_sge; } sgl_offset = 0; err = 1; } out: svc_rdma_put_context(tmp_sge_ctxt, 0); svc_rdma_put_context(tmp_ch_ctxt, 0); /* Detach arg pages. svc_recv will replenish them */ for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++) rqstp->rq_pages[ch_no] = NULL; /* * Detach res pages. svc_release must see a resused count of * zero or it will attempt to put them. */ while (rqstp->rq_resused) rqstp->rq_respages[--rqstp->rq_resused] = NULL; return err; } static int rdma_read_complete(struct svc_rqst *rqstp, struct svc_rdma_op_ctxt *head) { int page_no; int ret; BUG_ON(!head); /* Copy RPC pages */ for (page_no = 0; page_no < head->count; page_no++) { put_page(rqstp->rq_pages[page_no]); rqstp->rq_pages[page_no] = head->pages[page_no]; } /* Point rq_arg.pages past header */ rqstp->rq_arg.pages = &rqstp->rq_pages[head->sge[0].length]; rqstp->rq_arg.page_len = head->arg.page_len; rqstp->rq_arg.page_base = head->arg.page_base; /* rq_respages starts after the last arg page */ rqstp->rq_respages = &rqstp->rq_arg.pages[page_no]; rqstp->rq_resused = 0; /* Rebuild rq_arg head and tail. */ rqstp->rq_arg.head[0] = head->arg.head[0]; rqstp->rq_arg.tail[0] = head->arg.tail[0]; rqstp->rq_arg.len = head->arg.len; rqstp->rq_arg.buflen = head->arg.buflen; /* Free the context */ svc_rdma_put_context(head, 0); /* XXX: What should this be? */ rqstp->rq_prot = IPPROTO_MAX; ret = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len + rqstp->rq_arg.tail[0].iov_len; dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, " "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, rqstp->rq_arg.head[0].iov_len); svc_xprt_received(rqstp->rq_xprt); return ret; } /* * Set up the rqstp thread context to point to the RQ buffer. If * necessary, pull additional data from the client with an RDMA_READ * request. */ int svc_rdma_recvfrom(struct svc_rqst *rqstp) { struct svc_xprt *xprt = rqstp->rq_xprt; struct svcxprt_rdma *rdma_xprt = container_of(xprt, struct svcxprt_rdma, sc_xprt); struct svc_rdma_op_ctxt *ctxt = NULL; struct rpcrdma_msg *rmsgp; int ret = 0; int len; dprintk("svcrdma: rqstp=%p\n", rqstp); spin_lock_bh(&rdma_xprt->sc_read_complete_lock); if (!list_empty(&rdma_xprt->sc_read_complete_q)) { ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, struct svc_rdma_op_ctxt, dto_q); list_del_init(&ctxt->dto_q); } spin_unlock_bh(&rdma_xprt->sc_read_complete_lock); if (ctxt) return rdma_read_complete(rqstp, ctxt); spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, struct svc_rdma_op_ctxt, dto_q); list_del_init(&ctxt->dto_q); } else { atomic_inc(&rdma_stat_rq_starve); clear_bit(XPT_DATA, &xprt->xpt_flags); ctxt = NULL; } spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); if (!ctxt) { /* This is the EAGAIN path. The svc_recv routine will * return -EAGAIN, the nfsd thread will go to call into * svc_recv again and we shouldn't be on the active * transport list */ if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) goto close_out; BUG_ON(ret); goto out; } dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n", ctxt, rdma_xprt, rqstp, ctxt->wc_status); BUG_ON(ctxt->wc_status != IB_WC_SUCCESS); atomic_inc(&rdma_stat_recv); /* Build up the XDR from the receive buffers. */ rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len); /* Decode the RDMA header. */ len = svc_rdma_xdr_decode_req(&rmsgp, rqstp); rqstp->rq_xprt_hlen = len; /* If the request is invalid, reply with an error */ if (len < 0) { if (len == -ENOSYS) (void)svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS); goto close_out; } /* Read read-list data. */ ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt); if (ret > 0) { /* read-list posted, defer until data received from client. */ svc_xprt_received(xprt); return 0; } if (ret < 0) { /* Post of read-list failed, free context. */ svc_rdma_put_context(ctxt, 1); return 0; } ret = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len + rqstp->rq_arg.tail[0].iov_len; svc_rdma_put_context(ctxt, 0); out: dprintk("svcrdma: ret = %d, rq_arg.len =%d, " "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, rqstp->rq_arg.head[0].iov_len); rqstp->rq_prot = IPPROTO_MAX; svc_xprt_copy_addrs(rqstp, xprt); svc_xprt_received(xprt); return ret; close_out: if (ctxt) svc_rdma_put_context(ctxt, 1); dprintk("svcrdma: transport %p is closing\n", xprt); /* * Set the close bit and enqueue it. svc_recv will see the * close bit and call svc_xprt_delete */ set_bit(XPT_CLOSE, &xprt->xpt_flags); svc_xprt_received(xprt); return 0; }