#define RPCDBG_FACILITY RPCDBG_SVCXPRT
+static void svc_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc);
+static void svc_rdma_wc_read_done(struct ib_cq *cq, struct ib_wc *wc);
+
/* Each R/W context contains state for one chain of RDMA Read or
* Write Work Requests.
*
info->wi_nsegs = be32_to_cpup(++chunk);
info->wi_segs = ++chunk;
svc_rdma_cc_init(rdma, &info->wi_cc, DMA_TO_DEVICE);
+ info->wi_cc.cc_cqe.done = svc_rdma_write_done;
return info;
}
svc_rdma_write_info_free(info);
}
+/* State for pulling a Read chunk.
+ */
+struct svc_rdma_read_info {
+ struct svc_rdma_op_ctxt *ri_readctxt;
+ unsigned int ri_position;
+ unsigned int ri_pageno;
+ unsigned int ri_pageoff;
+ unsigned int ri_chunklen;
+
+ struct svc_rdma_chunk_ctxt ri_cc;
+};
+
+static struct svc_rdma_read_info *
+svc_rdma_read_info_alloc(struct svcxprt_rdma *rdma)
+{
+ struct svc_rdma_read_info *info;
+
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return info;
+
+ svc_rdma_cc_init(rdma, &info->ri_cc, DMA_FROM_DEVICE);
+ info->ri_cc.cc_cqe.done = svc_rdma_wc_read_done;
+ return info;
+}
+
+static void svc_rdma_read_info_free(struct svc_rdma_read_info *info)
+{
+ svc_rdma_cc_release(&info->ri_cc);
+ kfree(info);
+}
+
+/**
+ * svc_rdma_wc_read_done - Handle completion of an RDMA Read ctx
+ * @cq: controlling Completion Queue
+ * @wc: Work Completion
+ *
+ */
+static void svc_rdma_wc_read_done(struct ib_cq *cq, struct ib_wc *wc)
+{
+ struct ib_cqe *cqe = wc->wr_cqe;
+ struct svc_rdma_chunk_ctxt *cc =
+ container_of(cqe, struct svc_rdma_chunk_ctxt, cc_cqe);
+ struct svcxprt_rdma *rdma = cc->cc_rdma;
+ struct svc_rdma_read_info *info =
+ container_of(cc, struct svc_rdma_read_info, ri_cc);
+
+ atomic_add(cc->cc_sqecount, &rdma->sc_sq_avail);
+ wake_up(&rdma->sc_send_wait);
+
+ if (unlikely(wc->status != IB_WC_SUCCESS)) {
+ set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
+ if (wc->status != IB_WC_WR_FLUSH_ERR)
+ pr_err("svcrdma: read ctx: %s (%u/0x%x)\n",
+ ib_wc_status_msg(wc->status),
+ wc->status, wc->vendor_err);
+ svc_rdma_put_context(info->ri_readctxt, 1);
+ } else {
+ spin_lock(&rdma->sc_rq_dto_lock);
+ list_add_tail(&info->ri_readctxt->list,
+ &rdma->sc_read_complete_q);
+ spin_unlock(&rdma->sc_rq_dto_lock);
+
+ set_bit(XPT_DATA, &rdma->sc_xprt.xpt_flags);
+ svc_xprt_enqueue(&rdma->sc_xprt);
+ }
+
+ svc_rdma_read_info_free(info);
+}
+
/* This function sleeps when the transport's Send Queue is congested.
*
* Assumptions:
__be32 *seg;
int ret;
- cc->cc_cqe.done = svc_rdma_write_done;
seg = info->wi_segs + info->wi_seg_no * rpcrdma_segment_maxsz;
do {
unsigned int write_len;
svc_rdma_write_info_free(info);
return ret;
}
+
+static int svc_rdma_build_read_segment(struct svc_rdma_read_info *info,
+ struct svc_rqst *rqstp,
+ u32 rkey, u32 len, u64 offset)
+{
+ struct svc_rdma_op_ctxt *head = info->ri_readctxt;
+ struct svc_rdma_chunk_ctxt *cc = &info->ri_cc;
+ struct svc_rdma_rw_ctxt *ctxt;
+ unsigned int sge_no, seg_len;
+ struct scatterlist *sg;
+ int ret;
+
+ sge_no = PAGE_ALIGN(info->ri_pageoff + len) >> PAGE_SHIFT;
+ ctxt = svc_rdma_get_rw_ctxt(cc->cc_rdma, sge_no);
+ if (!ctxt)
+ goto out_noctx;
+ ctxt->rw_nents = sge_no;
+
+ dprintk("svcrdma: reading segment %u@0x%016llx:0x%08x (%u sges)\n",
+ len, offset, rkey, sge_no);
+
+ sg = ctxt->rw_sg_table.sgl;
+ for (sge_no = 0; sge_no < ctxt->rw_nents; sge_no++) {
+ seg_len = min_t(unsigned int, len,
+ PAGE_SIZE - info->ri_pageoff);
+
+ head->arg.pages[info->ri_pageno] =
+ rqstp->rq_pages[info->ri_pageno];
+ if (!info->ri_pageoff)
+ head->count++;
+
+ sg_set_page(sg, rqstp->rq_pages[info->ri_pageno],
+ seg_len, info->ri_pageoff);
+ sg = sg_next(sg);
+
+ info->ri_pageoff += seg_len;
+ if (info->ri_pageoff == PAGE_SIZE) {
+ info->ri_pageno++;
+ info->ri_pageoff = 0;
+ }
+ len -= seg_len;
+
+ /* Safety check */
+ if (len &&
+ &rqstp->rq_pages[info->ri_pageno + 1] > rqstp->rq_page_end)
+ goto out_overrun;
+ }
+
+ ret = rdma_rw_ctx_init(&ctxt->rw_ctx, cc->cc_rdma->sc_qp,
+ cc->cc_rdma->sc_port_num,
+ ctxt->rw_sg_table.sgl, ctxt->rw_nents,
+ 0, offset, rkey, DMA_FROM_DEVICE);
+ if (ret < 0)
+ goto out_initerr;
+
+ list_add(&ctxt->rw_list, &cc->cc_rwctxts);
+ cc->cc_sqecount += ret;
+ return 0;
+
+out_noctx:
+ dprintk("svcrdma: no R/W ctxs available\n");
+ return -ENOMEM;
+
+out_overrun:
+ dprintk("svcrdma: request overruns rq_pages\n");
+ return -EINVAL;
+
+out_initerr:
+ svc_rdma_put_rw_ctxt(cc->cc_rdma, ctxt);
+ pr_err("svcrdma: failed to map pagelist (%d)\n", ret);
+ return -EIO;
+}
+
+static int svc_rdma_build_read_chunk(struct svc_rqst *rqstp,
+ struct svc_rdma_read_info *info,
+ __be32 *p)
+{
+ int ret;
+
+ info->ri_chunklen = 0;
+ while (*p++ != xdr_zero) {
+ u32 rs_handle, rs_length;
+ u64 rs_offset;
+
+ if (be32_to_cpup(p++) != info->ri_position)
+ break;
+ rs_handle = be32_to_cpup(p++);
+ rs_length = be32_to_cpup(p++);
+ p = xdr_decode_hyper(p, &rs_offset);
+
+ ret = svc_rdma_build_read_segment(info, rqstp,
+ rs_handle, rs_length,
+ rs_offset);
+ if (ret < 0)
+ break;
+
+ info->ri_chunklen += rs_length;
+ }
+
+ return ret;
+}
+
+/* If there is inline content following the Read chunk, append it to
+ * the page list immediately following the data payload. This has to
+ * be done after the reader function has determined how many pages
+ * were consumed for RDMA Read.
+ *
+ * On entry, ri_pageno and ri_pageoff point directly to the end of the
+ * page list. On exit, both have been updated to the new "next byte".
+ *
+ * Assumptions:
+ * - Inline content fits entirely in rq_pages[0]
+ * - Trailing content is only a handful of bytes
+ */
+static int svc_rdma_copy_tail(struct svc_rqst *rqstp,
+ struct svc_rdma_read_info *info)
+{
+ struct svc_rdma_op_ctxt *head = info->ri_readctxt;
+ unsigned int tail_length, remaining;
+ u8 *srcp, *destp;
+
+ /* Assert that all inline content fits in page 0. This is an
+ * implementation limit, not a protocol limit.
+ */
+ if (head->arg.head[0].iov_len > PAGE_SIZE) {
+ pr_warn_once("svcrdma: too much trailing inline content\n");
+ return -EINVAL;
+ }
+
+ srcp = head->arg.head[0].iov_base;
+ srcp += info->ri_position;
+ tail_length = head->arg.head[0].iov_len - info->ri_position;
+ remaining = tail_length;
+
+ /* If there is room on the last page in the page list, try to
+ * fit the trailing content there.
+ */
+ if (info->ri_pageoff > 0) {
+ unsigned int len;
+
+ len = min_t(unsigned int, remaining,
+ PAGE_SIZE - info->ri_pageoff);
+ destp = page_address(rqstp->rq_pages[info->ri_pageno]);
+ destp += info->ri_pageoff;
+
+ memcpy(destp, srcp, len);
+ srcp += len;
+ destp += len;
+ info->ri_pageoff += len;
+ remaining -= len;
+
+ if (info->ri_pageoff == PAGE_SIZE) {
+ info->ri_pageno++;
+ info->ri_pageoff = 0;
+ }
+ }
+
+ /* Otherwise, a fresh page is needed. */
+ if (remaining) {
+ head->arg.pages[info->ri_pageno] =
+ rqstp->rq_pages[info->ri_pageno];
+ head->count++;
+
+ destp = page_address(rqstp->rq_pages[info->ri_pageno]);
+ memcpy(destp, srcp, remaining);
+ info->ri_pageoff += remaining;
+ }
+
+ head->arg.page_len += tail_length;
+ head->arg.len += tail_length;
+ head->arg.buflen += tail_length;
+ return 0;
+}
+
+/* Construct RDMA Reads to pull over a normal Read chunk. The chunk
+ * data lands in the page list of head->arg.pages.
+ *
+ * Currently NFSD does not look at the head->arg.tail[0] iovec.
+ * Therefore, XDR round-up of the Read chunk and trailing
+ * inline content must both be added at the end of the pagelist.
+ */
+static int svc_rdma_build_normal_read_chunk(struct svc_rqst *rqstp,
+ struct svc_rdma_read_info *info,
+ __be32 *p)
+{
+ struct svc_rdma_op_ctxt *head = info->ri_readctxt;
+ int ret;
+
+ dprintk("svcrdma: Reading Read chunk at position %u\n",
+ info->ri_position);
+
+ info->ri_pageno = head->hdr_count;
+ info->ri_pageoff = 0;
+
+ ret = svc_rdma_build_read_chunk(rqstp, info, p);
+ if (ret < 0)
+ goto out;
+
+ /* Read chunk may need XDR round-up (see RFC 5666, s. 3.7).
+ */
+ if (info->ri_chunklen & 3) {
+ u32 padlen = 4 - (info->ri_chunklen & 3);
+
+ info->ri_chunklen += padlen;
+
+ /* NB: data payload always starts on XDR alignment,
+ * thus the pad can never contain a page boundary.
+ */
+ info->ri_pageoff += padlen;
+ if (info->ri_pageoff == PAGE_SIZE) {
+ info->ri_pageno++;
+ info->ri_pageoff = 0;
+ }
+ }
+
+ head->arg.page_len = info->ri_chunklen;
+ head->arg.len += info->ri_chunklen;
+ head->arg.buflen += info->ri_chunklen;
+
+ if (info->ri_position < head->arg.head[0].iov_len) {
+ ret = svc_rdma_copy_tail(rqstp, info);
+ if (ret < 0)
+ goto out;
+ }
+ head->arg.head[0].iov_len = info->ri_position;
+
+out:
+ return ret;
+}
+
+/* Construct RDMA Reads to pull over a Position Zero Read chunk.
+ * The start of the data lands in the first page just after
+ * the Transport header, and the rest lands in the page list of
+ * head->arg.pages.
+ *
+ * Assumptions:
+ * - A PZRC has an XDR-aligned length (no implicit round-up).
+ * - There can be no trailing inline content (IOW, we assume
+ * a PZRC is never sent in an RDMA_MSG message, though it's
+ * allowed by spec).
+ */
+static int svc_rdma_build_pz_read_chunk(struct svc_rqst *rqstp,
+ struct svc_rdma_read_info *info,
+ __be32 *p)
+{
+ struct svc_rdma_op_ctxt *head = info->ri_readctxt;
+ int ret;
+
+ dprintk("svcrdma: Reading Position Zero Read chunk\n");
+
+ info->ri_pageno = head->hdr_count - 1;
+ info->ri_pageoff = offset_in_page(head->byte_len);
+
+ ret = svc_rdma_build_read_chunk(rqstp, info, p);
+ if (ret < 0)
+ goto out;
+
+ head->arg.len += info->ri_chunklen;
+ head->arg.buflen += info->ri_chunklen;
+
+ if (head->arg.len <= head->sge[0].length) {
+ /* Transport header and RPC message fit entirely
+ * in page where head iovec resides.
+ */
+ head->arg.head[0].iov_len = info->ri_chunklen;
+ } else {
+ /* Transport header and part of RPC message reside
+ * in the head iovec's page.
+ */
+ head->arg.head[0].iov_len =
+ head->sge[0].length - head->byte_len;
+ head->arg.page_len =
+ info->ri_chunklen - head->arg.head[0].iov_len;
+ }
+
+out:
+ return ret;
+}
+
+/**
+ * svc_rdma_recv_read_chunk - Pull a Read chunk from the client
+ * @rdma: controlling RDMA transport
+ * @rqstp: set of pages to use as Read sink buffers
+ * @head: pages under I/O collect here
+ * @p: pointer to start of Read chunk
+ *
+ * Returns:
+ * %0 if all needed RDMA Reads were posted successfully,
+ * %-EINVAL if client provided too many segments,
+ * %-ENOMEM if rdma_rw context pool was exhausted,
+ * %-ENOTCONN if posting failed (connection is lost),
+ * %-EIO if rdma_rw initialization failed (DMA mapping, etc).
+ *
+ * Assumptions:
+ * - All Read segments in @p have the same Position value.
+ */
+int svc_rdma_recv_read_chunk(struct svcxprt_rdma *rdma, struct svc_rqst *rqstp,
+ struct svc_rdma_op_ctxt *head, __be32 *p)
+{
+ struct svc_rdma_read_info *info;
+ struct page **page;
+ int ret;
+
+ /* The request (with page list) is constructed in
+ * head->arg. Pages involved with RDMA Read I/O are
+ * transferred there.
+ */
+ head->hdr_count = head->count;
+ head->arg.head[0] = rqstp->rq_arg.head[0];
+ head->arg.tail[0] = rqstp->rq_arg.tail[0];
+ head->arg.pages = head->pages;
+ head->arg.page_base = 0;
+ head->arg.page_len = 0;
+ head->arg.len = rqstp->rq_arg.len;
+ head->arg.buflen = rqstp->rq_arg.buflen;
+
+ info = svc_rdma_read_info_alloc(rdma);
+ if (!info)
+ return -ENOMEM;
+ info->ri_readctxt = head;
+
+ info->ri_position = be32_to_cpup(p + 1);
+ if (info->ri_position)
+ ret = svc_rdma_build_normal_read_chunk(rqstp, info, p);
+ else
+ ret = svc_rdma_build_pz_read_chunk(rqstp, info, p);
+
+ /* Mark the start of the pages that can be used for the reply */
+ if (info->ri_pageoff > 0)
+ info->ri_pageno++;
+ rqstp->rq_respages = &rqstp->rq_pages[info->ri_pageno];
+ rqstp->rq_next_page = rqstp->rq_respages + 1;
+
+ if (ret < 0)
+ goto out;
+
+ ret = svc_rdma_post_chunk_ctxt(&info->ri_cc);
+
+out:
+ /* Read sink pages have been moved from rqstp->rq_pages to
+ * head->arg.pages. Force svc_recv to refill those slots
+ * in rq_pages.
+ */
+ for (page = rqstp->rq_pages; page < rqstp->rq_respages; page++)
+ *page = NULL;
+
+ if (ret < 0)
+ svc_rdma_read_info_free(info);
+ return ret;
+}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff