new file mode 100644
@@ -0,0 +1,1560 @@
+/*
+ * Software iWARP device driver for Linux
+ *
+ * Authors: Bernard Metzler <bmt@zurich.ibm.com>
+ * Fredy Neeser <nfd@zurich.ibm.com>
+ *
+ * Copyright (c) 2008-2011, IBM Corporation
+ *
+ * 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 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 IBM nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/net.h>
+#include <linux/scatterlist.h>
+#include <linux/highmem.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/tcp.h>
+
+#include <rdma/iw_cm.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_smi.h>
+#include <rdma/ib_user_verbs.h>
+#include <rdma/ib_umem.h>
+
+#include "siw.h"
+#include "siw_obj.h"
+#include "siw_cm.h"
+
+
+/*
+ * ----------------------------
+ * DDP reassembly for Softiwarp
+ * ----------------------------
+ * For the ordering of transmitted DDP segments, the relevant iWARP ordering
+ * rules are as follows:
+ *
+ * - RDMAP (RFC 5040): Section 7.5, Rule 17:
+ * "RDMA Read Response Message processing at the Remote Peer (reading
+ * the specified Tagged Buffer) MUST be started only after the RDMA
+ * Read Request Message has been Delivered by the DDP layer (thus,
+ * all previous RDMA Messages have been properly submitted for
+ * ordered Placement)."
+ *
+ * - DDP (RFC 5041): Section 5.3:
+ * "At the Data Source, DDP:
+ * o MUST transmit DDP Messages in the order they were submitted to
+ * the DDP layer,
+ * o SHOULD transmit DDP Segments within a DDP Message in increasing
+ * MO order for Untagged DDP Messages, and in increasing TO order
+ * for Tagged DDP Messages."
+ *
+ * Combining these rules implies that, although RDMAP does not provide
+ * ordering between operations that are generated from the two ends of an
+ * RDMAP stream, DDP *must not* transmit an RDMA Read Response Message before
+ * it has finished transmitting SQ operations that were already submitted
+ * to the DDP layer. It follows that an iWARP transmitter must fully
+ * serialize RDMAP messages belonging to the same QP.
+ *
+ * Given that a TCP socket receives DDP segments in peer transmit order,
+ * we obtain the following ordering of received DDP segments:
+ *
+ * (i) the received DDP segments of RDMAP messages for the same QP
+ * cannot be interleaved
+ * (ii) the received DDP segments of a single RDMAP message *should*
+ * arrive in order.
+ *
+ * The Softiwarp transmitter obeys rule #2 in DDP Section 5.3.
+ * With this property, the "should" becomes a "must" in (ii) above,
+ * which simplifies DDP reassembly considerably.
+ * The Softiwarp receiver currently relies on this property
+ * and reports an error if DDP segments of the same RDMAP message
+ * do not arrive in sequence.
+ */
+
+static inline int siw_crc_rxhdr(struct siw_iwarp_rx *ctx)
+{
+ crypto_hash_init(&ctx->mpa_crc_hd);
+
+ return siw_crc_array(&ctx->mpa_crc_hd, (u8 *)&ctx->hdr,
+ ctx->fpdu_part_rcvd);
+}
+
+
+/*
+ * siw_rx_umem_init()
+ *
+ * Given memory region @mr and tagged offset @t_off within @mr,
+ * resolve corresponding ib_umem_chunk memory chunk pointer
+ * and update receive context variables to point at receive position.
+ * returns 0 on sucess and failure otherwise.
+ *
+ * NOTE: This function expects virtual addresses.
+ * TODO: Function needs generalization to support relative adressing
+ * aka "ZBVA".
+ *
+ * @rctx: Receive Context to be updated
+ * @mr: Memory Region
+ * @t_off: Offset within Memory Region
+ *
+ */
+static int siw_rx_umem_init(struct siw_iwarp_rx *rctx, struct siw_mr *mr,
+ u64 t_off)
+{
+ struct ib_umem_chunk *chunk;
+ u64 off_mr; /* offset into MR */
+ int psge_idx; /* Index of PSGE */
+
+ off_mr = t_off - (mr->mem.va & PAGE_MASK);
+ /*
+ * Equivalent to
+ * off_mr = t_off - mr->mem.va;
+ * off_mr += mr->umem->offset;
+ */
+
+ /* Skip pages not referenced by t_off */
+ psge_idx = off_mr >> PAGE_SHIFT;
+
+ list_for_each_entry(chunk, &mr->umem->chunk_list, list) {
+ if (psge_idx < chunk->nents)
+ break;
+ psge_idx -= chunk->nents;
+ }
+ if (psge_idx >= chunk->nents) {
+ dprint(DBG_MM|DBG_ON, "(QP%d): Short chunk list\n",
+ RX_QPID(rctx));
+ return -EINVAL;
+ }
+ rctx->pg_idx = psge_idx;
+ rctx->pg_off = off_mr & ~PAGE_MASK;
+ rctx->umem_chunk = chunk;
+
+ dprint(DBG_MM, "(QP%d): New chunk, idx %d\n", RX_QPID(rctx), psge_idx);
+ return 0;
+}
+
+
+/*
+ * siw_rx_umem()
+ *
+ * Receive data of @len into target referenced by @rctx.
+ * This function does not check if umem is within bounds requested by
+ * @len and @t_off. @umem_ends indicates if routine should
+ * not update chunk position pointers after the point it is
+ * currently receiving
+ *
+ * @rctx: Receive Context
+ * @len: Number of bytes to place
+ * @umen_ends: 1, if rctx chunk pointer should not be updated after len.
+ */
+static int siw_rx_umem(struct siw_iwarp_rx *rctx, int len, int umem_ends)
+{
+ struct scatterlist *p_list;
+ void *dest;
+ struct ib_umem_chunk *chunk = rctx->umem_chunk;
+ int pg_off = rctx->pg_off,
+ copied = 0,
+ bytes,
+ rv;
+
+ while (len) {
+ bytes = min(len, (int)PAGE_SIZE - pg_off);
+ p_list = &chunk->page_list[rctx->pg_idx];
+
+ dest = kmap_atomic(sg_page(p_list), KM_SOFTIRQ0);
+
+ rv = skb_copy_bits(rctx->skb, rctx->skb_offset, dest + pg_off,
+ bytes);
+
+ dprint(DBG_RX, "(QP%d): Page #%d, "
+ "bytes=%u, rv=%d returned by skb_copy_bits()\n",
+ RX_QPID(rctx), rctx->pg_idx, bytes, rv);
+
+ if (likely(!rv)) {
+ if (rctx->crc_enabled)
+ rv = siw_crc_sg(&rctx->mpa_crc_hd, p_list,
+ pg_off, bytes);
+
+ rctx->skb_offset += bytes;
+ copied += bytes;
+ len -= bytes;
+ pg_off += bytes;
+ }
+
+ kunmap_atomic(dest, KM_SOFTIRQ0);
+
+ if (unlikely(rv)) {
+ rctx->skb_copied += copied;
+ rctx->skb_new -= copied;
+ copied = -EFAULT;
+
+ dprint(DBG_RX|DBG_ON, "(QP%d): failed with %d\n",
+ RX_QPID(rctx), rv);
+
+ goto out;
+ }
+ if (pg_off == PAGE_SIZE) {
+ /*
+ * end of page
+ */
+ pg_off = 0;
+ /*
+ * reference next page chunk if
+ * - all pages in chunk used AND
+ * - current loop fills more into this umem
+ * OR the next receive will go into this umem
+ * starting at the position where we are leaving
+ * the routine.
+ */
+ if (++rctx->pg_idx == chunk->nents &&
+ (len > 0 || !umem_ends)) {
+
+ rctx->pg_idx = 0;
+ chunk = mem_chunk_next(chunk);
+ }
+ }
+ }
+ /*
+ * store chunk position for resume
+ */
+ rctx->umem_chunk = chunk;
+ rctx->pg_off = pg_off;
+
+ rctx->skb_copied += copied;
+ rctx->skb_new -= copied;
+out:
+ return copied;
+}
+
+static inline int siw_rx_kva(struct siw_iwarp_rx *rctx, int len, void *kva)
+{
+ int rv = skb_copy_bits(rctx->skb, rctx->skb_offset, kva, len);
+
+ if (likely(!rv)) {
+ rctx->skb_offset += len;
+ rctx->skb_copied += len;
+ rctx->skb_new -= len;
+ if (rctx->crc_enabled) {
+ rv = siw_crc_array(&rctx->mpa_crc_hd, kva, len);
+ if (rv)
+ goto done;
+ }
+ rv = len;
+ }
+done:
+ return rv;
+}
+
+/*
+ * siw_rresp_check_ntoh()
+ *
+ * Check incoming RRESP fragment header against expected
+ * header values and update expected values for potential next
+ * fragment.
+ *
+ * NOTE: This function must be called only if a RRESP DDP segment
+ * starts but not for fragmented consecutive pieces of an
+ * already started DDP segement.
+ */
+static inline int siw_rresp_check_ntoh(struct siw_iwarp_rx *rctx)
+{
+ struct iwarp_rdma_rresp *rresp = &rctx->hdr.rresp;
+ struct siw_wqe *wqe = rctx->dest.wqe;
+
+ u32 sink_stag = be32_to_cpu(rresp->sink_stag);
+ u64 sink_to = be64_to_cpu(rresp->sink_to);
+
+ if (rctx->first_ddp_seg) {
+ rctx->ddp_stag = wqe->wr.rread.sge[0].lkey;
+ rctx->ddp_to = wqe->wr.rread.sge[0].addr;
+ }
+ if (rctx->ddp_stag != sink_stag) {
+ dprint(DBG_RX|DBG_ON,
+ " received STAG=%08x, expected STAG=%08x\n",
+ sink_stag, rctx->ddp_stag);
+ /*
+ * Verbs: RI_EVENT_QP_LLP_INTEGRITY_ERROR_BAD_FPDU
+ */
+ return -EINVAL;
+ }
+ if (rctx->ddp_to != sink_to) {
+ dprint(DBG_RX|DBG_ON,
+ " received TO=%016llx, expected TO=%016llx\n",
+ (unsigned long long)sink_to,
+ (unsigned long long)rctx->ddp_to);
+ /*
+ * Verbs: RI_EVENT_QP_LLP_INTEGRITY_ERROR_BAD_FPDU
+ */
+ return -EINVAL;
+ }
+ if (!rctx->more_ddp_segs && (wqe->processed + rctx->fpdu_part_rem
+ != wqe->bytes)) {
+ dprint(DBG_RX|DBG_ON,
+ " RRESP length does not match RREQ, "
+ "peer sent=%d, expected %d\n",
+ wqe->processed + rctx->fpdu_part_rem, wqe->bytes);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * siw_write_check_ntoh()
+ *
+ * Check incoming WRITE fragment header against expected
+ * header values and update expected values for potential next
+ * fragment
+ *
+ * NOTE: This function must be called only if a WRITE DDP segment
+ * starts but not for fragmented consecutive pieces of an
+ * already started DDP segement.
+ */
+static inline int siw_write_check_ntoh(struct siw_iwarp_rx *rctx)
+{
+ struct iwarp_rdma_write *write = &rctx->hdr.rwrite;
+
+ u32 sink_stag = be32_to_cpu(write->sink_stag);
+ u64 sink_to = be64_to_cpu(write->sink_to);
+
+ if (rctx->first_ddp_seg) {
+ rctx->ddp_stag = sink_stag;
+ rctx->ddp_to = sink_to;
+ } else {
+ if (rctx->ddp_stag != sink_stag) {
+ dprint(DBG_RX|DBG_ON,
+ " received STAG=%08x, expected STAG=%08x\n",
+ sink_stag, rctx->ddp_stag);
+ /*
+ * Verbs: RI_EVENT_QP_LLP_INTEGRITY_ERROR_BAD_FPDU
+ */
+ return -EINVAL;
+ }
+ if (rctx->ddp_to != sink_to) {
+ dprint(DBG_RX|DBG_ON,
+ " received TO=%016llx, expected TO=%016llx\n",
+ (unsigned long long)sink_to,
+ (unsigned long long)rctx->ddp_to);
+ /*
+ * Verbs: RI_EVENT_QP_LLP_INTEGRITY_ERROR_BAD_FPDU
+ */
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+/*
+ * siw_send_check_ntoh()
+ *
+ * Check incoming SEND fragment header against expected
+ * header values and update expected MSN if no next
+ * fragment expected
+ *
+ * NOTE: This function must be called only if a SEND DDP segment
+ * starts but not for fragmented consecutive pieces of an
+ * already started DDP segement.
+ */
+static inline int siw_send_check_ntoh(struct siw_iwarp_rx *rctx)
+{
+ struct iwarp_send *send = &rctx->hdr.send;
+ struct siw_wqe *wqe = rctx->dest.wqe;
+
+ u32 ddp_msn = be32_to_cpu(send->ddp_msn);
+ u32 ddp_mo = be32_to_cpu(send->ddp_mo);
+ u32 ddp_qn = be32_to_cpu(send->ddp_qn);
+
+ if (ddp_qn != RDMAP_UNTAGGED_QN_SEND) {
+ dprint(DBG_RX|DBG_ON, " Invalid DDP QN %d for SEND\n",
+ ddp_qn);
+ return -EINVAL;
+ }
+ if (ddp_msn != rctx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]) {
+ dprint(DBG_RX|DBG_ON, " received MSN=%d, expected MSN=%d\n",
+ rctx->ddp_msn[RDMAP_UNTAGGED_QN_SEND], ddp_msn);
+ /*
+ * TODO: Error handling
+ * async_event= RI_EVENT_QP_RQ_PROTECTION_ERROR_MSN_GAP;
+ * cmpl_status= RI_WC_STATUS_LOCAL_QP_CATASTROPHIC;
+ */
+ return -EINVAL;
+ }
+ if (ddp_mo != wqe->processed) {
+ dprint(DBG_RX|DBG_ON, " Received MO=%u, expected MO=%u\n",
+ ddp_mo, wqe->processed);
+ /*
+ * Verbs: RI_EVENT_QP_LLP_INTEGRITY_ERROR_BAD_FPDU
+ */
+ return -EINVAL;
+ }
+ if (rctx->first_ddp_seg) {
+ /* initialize user memory write position */
+ rctx->sge_idx = 0;
+ rctx->sge_off = 0;
+ }
+ if (wqe->bytes < wqe->processed + rctx->fpdu_part_rem) {
+ dprint(DBG_RX|DBG_ON, " Receive space short: %d < %d\n",
+ wqe->bytes - wqe->processed, rctx->fpdu_part_rem);
+ wqe->wc_status = IB_WC_LOC_LEN_ERR;
+ return -EINVAL;
+ }
+ return 0;
+}
+
+
+/*
+ * siw_srq_fetch_wqe()
+ *
+ * Get one RQ wqe from SRQ and inform user
+ * if SRQ lower watermark reached
+ */
+static inline struct siw_wqe *siw_srq_fetch_wqe(struct siw_srq *srq)
+{
+ struct siw_wqe *wqe = NULL;
+ int qlen;
+
+ lock_srq(srq);
+ if (!list_empty(&srq->rq)) {
+ wqe = list_first_wqe(&srq->rq);
+ list_del_init(&wqe->list);
+ /*
+ * The SRQ wqe is counted for SRQ space until completed.
+ */
+ qlen = srq->max_wr - (atomic_read(&srq->space) + 1);
+ if (srq->armed && qlen < srq->limit) {
+ srq->armed = 0;
+ dprint(DBG_RX, " SRQ(%p): SRQ limit event\n", srq);
+ siw_srq_event(srq, IB_EVENT_SRQ_LIMIT_REACHED);
+ }
+ }
+ unlock_srq(srq);
+
+ return wqe;
+}
+
+static inline struct siw_wqe *siw_get_rqe(struct siw_qp *qp)
+{
+ struct siw_wqe *wqe = NULL;
+
+ if (!qp->srq) {
+ lock_rq(qp);
+ if (!list_empty(&qp->rq)) {
+ wqe = list_first_wqe(&qp->rq);
+ list_del_init(&wqe->list);
+ unlock_rq(qp);
+ } else {
+ unlock_rq(qp);
+ dprint(DBG_RX, " QP(%d): RQ empty!\n", QP_ID(qp));
+ }
+ } else {
+ wqe = siw_srq_fetch_wqe(qp->srq);
+ if (wqe) {
+ siw_qp_get(qp);
+ wqe->qp = qp;
+ } else
+ dprint(DBG_RX, " QP(%d): SRQ empty!\n", QP_ID(qp));
+ }
+ return wqe;
+}
+
+
+/*
+ * siw_proc_send:
+ *
+ * Process one incoming SEND and place data into memory referenced by
+ * receive wqe.
+ *
+ * Function supports partially received sends (suspending/resuming
+ * current receive wqe processing)
+ *
+ * return value:
+ * 0: reached the end of a DDP segment
+ * -EAGAIN: to be called again to finish the DDP segment
+ */
+int siw_proc_send(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ struct siw_wqe *wqe;
+ struct siw_sge *sge;
+ struct siw_mr *mr;
+ u32 data_bytes, /* all data bytes available */
+ rcvd_bytes; /* sum of data bytes rcvd */
+ int rv = 0;
+
+ if (rctx->first_ddp_seg) {
+ WARN_ON(rx_wqe(qp) != NULL);
+
+ wqe = siw_get_rqe(qp);
+ if (!wqe)
+ return -ENOENT;
+
+ rx_wqe(qp) = wqe;
+ wqe->wr_status = SR_WR_INPROGRESS;
+ } else {
+ wqe = rx_wqe(qp);
+ if (!wqe) {
+ /*
+ * this is a siw bug!
+ */
+ dprint(DBG_ON, "QP(%d): RQ failure\n", QP_ID(qp));
+ return -EPROTO;
+ }
+ }
+ if (rctx->state == SIW_GET_DATA_START) {
+ rv = siw_send_check_ntoh(rctx);
+ if (rv) {
+ siw_qp_event(qp, IB_EVENT_QP_FATAL);
+ return rv;
+ }
+ if (!rctx->fpdu_part_rem) /* zero length SEND */
+ return 0;
+ }
+ data_bytes = min(rctx->fpdu_part_rem, rctx->skb_new);
+ rcvd_bytes = 0;
+
+ while (data_bytes) {
+ struct siw_pd *pd;
+ u32 sge_bytes; /* data bytes avail for SGE */
+
+ sge = &wqe->wr.sgl.sge[rctx->sge_idx];
+
+ if (!sge->len) {
+ /* just skip empty sge's */
+ rctx->sge_idx++;
+ rctx->sge_off = 0;
+ continue;
+ }
+ sge_bytes = min(data_bytes, sge->len - rctx->sge_off);
+
+ /*
+ * check with QP's PD if no SRQ present, SRQ's PD otherwise
+ */
+ pd = qp->srq == NULL ? qp->pd : qp->srq->pd;
+
+ rv = siw_check_sge(pd, sge, SR_MEM_LWRITE, rctx->sge_off,
+ sge_bytes);
+ if (rv) {
+ siw_qp_event(qp, IB_EVENT_QP_ACCESS_ERR);
+ break;
+ }
+ mr = siw_mem2mr(sge->mem.obj);
+
+ if (mr->umem) {
+ /*
+ * Are we going to finish placing
+ * - the last fragment of the current SGE or
+ * - the last DDP segment (L=1) of the current
+ * RDMAP message?
+ *
+ * siw_rx_umem() must advance umem page_chunk position
+ * after sucessful receive only, if receive into
+ * current umem does not end.
+ * umem ends, if:
+ * - current SGE gets completely filled, OR
+ * - current MPA FPDU is last AND gets consumed now
+ */
+ int umem_ends =
+ ((sge_bytes + rctx->sge_off == sge->len) ||
+ (!rctx->more_ddp_segs &&
+ rctx->fpdu_part_rcvd + sge_bytes ==
+ rctx->fpdu_part_rem)) ? 1 : 0;
+
+ if (rctx->sge_off == 0) {
+ /*
+ * started a new sge: update receive pointers
+ */
+ rv = siw_rx_umem_init(rctx, mr, sge->addr);
+ if (rv)
+ break;
+ }
+ rv = siw_rx_umem(rctx, sge_bytes, umem_ends);
+ } else
+ rv = siw_rx_kva(rctx, sge_bytes,
+ (void *)(sge->addr + rctx->sge_off));
+ if (rv != sge_bytes) {
+ wqe->processed += rcvd_bytes;
+ return -EINVAL;
+ }
+ rctx->sge_off += rv;
+
+ if (rctx->sge_off == sge->len) {
+ rctx->sge_idx++;
+ rctx->sge_off = 0;
+ }
+ data_bytes -= rv;
+ rcvd_bytes += rv;
+
+ rctx->fpdu_part_rem -= rv;
+ rctx->fpdu_part_rcvd += rv;
+ }
+ wqe->processed += rcvd_bytes;
+
+ if (!rctx->fpdu_part_rem)
+ return 0;
+
+ return (rv < 0) ? rv : -EAGAIN;
+}
+
+/*
+ * siw_proc_write:
+ *
+ * Place incoming WRITE after referencing and checking target buffer
+
+ * Function supports partially received WRITEs (suspending/resuming
+ * current receive processing)
+ *
+ * return value:
+ * 0: reached the end of a DDP segment
+ * -EAGAIN: to be called again to finish the DDP segment
+ */
+
+int siw_proc_write(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ struct siw_dev *dev = qp->hdr.sdev;
+ struct siw_mem *mem;
+ struct siw_mr *mr;
+ int bytes,
+ rv;
+
+ if (rctx->state == SIW_GET_DATA_START) {
+
+ if (!rctx->fpdu_part_rem) /* zero length WRITE */
+ return 0;
+
+ rv = siw_write_check_ntoh(rctx);
+ if (rv) {
+ siw_qp_event(qp, IB_EVENT_QP_FATAL);
+ return rv;
+ }
+ }
+ bytes = min(rctx->fpdu_part_rem, rctx->skb_new);
+
+ /*
+ * NOTE: bytes > 0 is always true, since this routine
+ * gets only called if so.
+ */
+ if (rctx->first_ddp_seg) {
+ /* DEBUG Code, to be removed */
+ if (rx_mem(qp) != NULL) {
+ dprint(DBG_RX|DBG_ON, "(QP%d): Stale rctx state!\n",
+ QP_ID(qp));
+ return -EFAULT;
+ }
+ rx_mem(qp) = siw_mem_id2obj(dev, rctx->ddp_stag >> 8);
+ }
+ if (rx_mem(qp) == NULL) {
+ dprint(DBG_RX|DBG_ON, "(QP%d): "
+ "Sink STag not found or invalid, STag=0x%08x\n",
+ QP_ID(qp), rctx->ddp_stag);
+ return -EINVAL;
+ }
+ mem = rx_mem(qp);
+ /*
+ * Rtag not checked against mem's tag again because
+ * hdr check guarantees same tag as before if fragmented
+ */
+ rv = siw_check_mem(qp->pd, mem, rctx->ddp_to + rctx->fpdu_part_rcvd,
+ SR_MEM_RWRITE, bytes);
+ if (rv) {
+ siw_qp_event(qp, IB_EVENT_QP_ACCESS_ERR);
+ return rv;
+ }
+ mr = siw_mem2mr(mem);
+
+ if (mr->umem) {
+ /*
+ * Are we going to place the last piece of the last
+ * DDP segment of the current RDMAP message?
+ *
+ * It is last if:
+ * - rctx->fpdu_part_rem <= rctx->skb_new AND
+ * - payload_rem (of current DDP segment) <= rctx->skb_new
+ */
+ int last_write = ((rctx->fpdu_part_rem <= rctx->skb_new) &&
+ !rctx->more_ddp_segs) ? 1 : 0;
+
+ if (rctx->first_ddp_seg) {
+ rv = siw_rx_umem_init(rctx, mr, rctx->ddp_to);
+ if (rv)
+ return -EINVAL;
+
+ }
+ rv = siw_rx_umem(rctx, bytes, last_write);
+ } else
+ rv = siw_rx_kva(rctx, bytes,
+ (void *)(rctx->ddp_to +
+ rctx->fpdu_part_rcvd));
+
+ if (rv != bytes)
+ return -EINVAL;
+
+ rctx->fpdu_part_rem -= rv;
+ rctx->fpdu_part_rcvd += rv;
+
+ if (!rctx->fpdu_part_rem) {
+ rctx->ddp_to += rctx->fpdu_part_rcvd;
+ return 0;
+ }
+
+ return (rv < 0) ? rv : -EAGAIN;
+}
+
+/*
+ * inbound RREQ's cannot carry user data.
+ */
+int siw_proc_rreq(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ if (!rctx->fpdu_part_rem)
+ return 0;
+
+ dprint(DBG_ON|DBG_RX, "(QP%d): RREQ with MPA len %d\n", QP_ID(qp),
+ be16_to_cpu(rctx->hdr.ctrl.mpa_len));
+
+ return -EPROTO;
+}
+
+static inline struct siw_wqe *siw_get_irqe(struct siw_qp *qp)
+{
+ struct siw_wqe *wqe = NULL;
+
+ if (atomic_dec_return(&qp->irq_space) >= 0) {
+ wqe = siw_freeq_wqe_get(qp);
+ if (wqe) {
+ INIT_LIST_HEAD(&wqe->list);
+ wqe->processed = 0;
+ siw_qp_get(qp);
+ wqe->qp = qp;
+ wr_type(wqe) = SIW_WR_RDMA_READ_RESP;
+ } else
+ atomic_inc(&qp->irq_space);
+ } else
+ atomic_inc(&qp->irq_space);
+
+ return wqe;
+}
+
+/*
+ * siw_init_rresp:
+ *
+ * Process inbound RDMA READ REQ. Produce a pseudo READ RESPONSE WQE.
+ * Put it at the tail of the IRQ, if there is another WQE currently in
+ * transmit processing. If not, make it the current WQE to be processed
+ * and schedule transmit processing.
+ *
+ * Can be called from softirq context and from process
+ * context (RREAD socket loopback case!)
+ *
+ * return value:
+ * 0: success,
+ * failure code otherwise
+ */
+
+int siw_init_rresp(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ struct siw_wqe *rsp;
+
+ rsp = siw_get_irqe(qp);
+ if (rsp) {
+ rsp->wr.rresp.sge.len = be32_to_cpu(rctx->hdr.rreq.read_size);
+ rsp->bytes = rsp->wr.rresp.sge.len; /* redundant */
+
+ rsp->wr.rresp.sge.addr = be64_to_cpu(rctx->hdr.rreq.source_to);
+ rsp->wr.rresp.num_sge = rsp->bytes ? 1 : 0;
+
+ rsp->wr.rresp.sge.mem.obj = NULL; /* defer lookup */
+ rsp->wr.rresp.sge.lkey =
+ be32_to_cpu(rctx->hdr.rreq.source_stag);
+
+ rsp->wr.rresp.raddr = be64_to_cpu(rctx->hdr.rreq.sink_to);
+ rsp->wr.rresp.rtag = be32_to_cpu(rctx->hdr.rreq.sink_stag);
+
+ } else {
+ dprint(DBG_RX|DBG_ON, "(QP%d): IRD exceeded!\n", QP_ID(qp));
+ return -EPROTO;
+ }
+ rsp->wr_status = SR_WR_QUEUED;
+
+ /*
+ * Insert into IRQ
+ *
+ * TODO: Revisit ordering of genuine SQ WRs and Read Response
+ * pseudo-WRs. RDMAP specifies that there is no ordering among
+ * the two directions of transmission, so there is a degree of
+ * freedom.
+ *
+ * The current logic favours Read Responses over SQ work requests
+ * that are queued but not already in progress.
+ */
+ lock_sq(qp);
+ if (!tx_wqe(qp)) {
+ tx_wqe(qp) = rsp;
+ unlock_sq(qp);
+ /*
+ * schedule TX work, even if SQ was supended due to
+ * ORD limit: it is always OK (and may even prevent peers
+ * from appl lock) to send RRESPONSE's
+ */
+ siw_sq_queue_work(qp);
+ } else {
+ list_add_tail(&rsp->list, &qp->irq);
+ unlock_sq(qp);
+ }
+ return 0;
+}
+
+/*
+ * siw_proc_rresp:
+ *
+ * Place incoming RRESP data into memory referenced by RREQ WQE.
+ *
+ * Function supports partially received RRESP's (suspending/resuming
+ * current receive processing)
+ */
+int siw_proc_rresp(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ struct siw_wqe *wqe;
+ struct siw_mr *mr;
+ struct siw_sge *sge;
+ int bytes,
+ rv;
+
+ if (rctx->first_ddp_seg) {
+ WARN_ON(rx_wqe(qp) != NULL);
+ /*
+ * fetch pending RREQ from orq
+ */
+ lock_orq(qp);
+ if (!list_empty(&qp->orq)) {
+ wqe = list_first_entry(&qp->orq, struct siw_wqe, list);
+ list_del_init(&wqe->list);
+ } else {
+ unlock_orq(qp);
+ dprint(DBG_RX|DBG_ON, "(QP%d): ORQ empty\n",
+ QP_ID(qp));
+ /*
+ * TODO: Should generate an async error
+ */
+ rv = -ENODATA; /* or -ENOENT ? */
+ goto done;
+ }
+ unlock_orq(qp);
+
+ rx_wqe(qp) = wqe;
+
+ if (wr_type(wqe) != SIW_WR_RDMA_READ_REQ || wqe->processed) {
+ WARN_ON(wqe->processed);
+ WARN_ON(wr_type(wqe) != SIW_WR_RDMA_READ_REQ);
+ rv = -EINVAL;
+ goto done;
+ }
+
+ wqe->wr_status = SR_WR_INPROGRESS;
+
+ rv = siw_rresp_check_ntoh(rctx);
+ if (rv) {
+ siw_qp_event(qp, IB_EVENT_QP_FATAL);
+ goto done;
+ }
+ } else {
+ wqe = rx_wqe(qp);
+ if (!wqe) {
+ WARN_ON(1);
+ rv = -ENODATA;
+ goto done;
+ }
+ }
+ if (!rctx->fpdu_part_rem) /* zero length RRESPONSE */
+ return 0;
+
+ bytes = min(rctx->fpdu_part_rem, rctx->skb_new);
+ sge = wqe->wr.rread.sge; /* there is only one */
+
+ /*
+ * check target memory which resolves memory on first fragment
+ */
+ rv = siw_check_sge(qp->pd, sge, SR_MEM_LWRITE, wqe->processed, bytes);
+ if (rv) {
+ dprint(DBG_RX|DBG_ON, "(QP%d): siw_check_sge failed: %d\n",
+ QP_ID(qp), rv);
+ wqe->wc_status = IB_WC_LOC_PROT_ERR;
+ siw_qp_event(qp, IB_EVENT_QP_ACCESS_ERR);
+ goto done;
+ }
+ mr = siw_mem2mr(sge->mem.obj);
+
+ if (mr->umem) {
+ /*
+ * Are we going to finish placing the last DDP segment (L=1)
+ * of the current RDMAP message?
+ *
+ * NOTE: siw_rresp_check_ntoh() guarantees that the
+ * last inbound RDMAP Read Response message exactly matches
+ * with the RREQ WR.
+ */
+ int is_last = (bytes + wqe->processed == wqe->bytes) ? 1 : 0;
+
+ if (rctx->first_ddp_seg) {
+ rv = siw_rx_umem_init(rctx, mr, sge->addr);
+ if (rv) {
+ wqe->wc_status = IB_WC_LOC_PROT_ERR;
+ goto done;
+ }
+ }
+ rv = siw_rx_umem(rctx, bytes, is_last);
+ } else
+ rv = siw_rx_kva(rctx, bytes,
+ (void *)(sge->addr + wqe->processed));
+ if (rv != bytes) {
+ wqe->wc_status = IB_WC_GENERAL_ERR;
+ rv = -EINVAL;
+ goto done;
+ }
+ rctx->fpdu_part_rem -= rv;
+ rctx->fpdu_part_rcvd += rv;
+
+ wqe->processed += rv;
+
+ if (!rctx->fpdu_part_rem) {
+ rctx->ddp_to += rctx->fpdu_part_rcvd;
+ return 0;
+ }
+done:
+ return (rv < 0) ? rv : -EAGAIN;
+}
+
+static void siw_drain_pkt(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ char buf[128];
+ int len;
+
+ dprint(DBG_ON|DBG_RX, " (QP%d): drain %d bytes\n",
+ QP_ID(qp), rctx->fpdu_part_rem);
+
+ while (rctx->fpdu_part_rem) {
+ len = min(rctx->fpdu_part_rem, 128);
+
+ skb_copy_bits(rctx->skb, rctx->skb_offset,
+ buf, rctx->fpdu_part_rem);
+
+ rctx->skb_copied += len;
+ rctx->skb_offset += len;
+ rctx->skb_new -= len;
+ rctx->fpdu_part_rem -= len;
+ rctx->fpdu_part_rcvd += len;
+ }
+}
+
+int siw_proc_unsupp(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ WARN_ON(1);
+ siw_drain_pkt(qp, rctx);
+ return 0;
+}
+
+
+int siw_proc_terminate(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ dprint(DBG_ON, " (QP%d): RX Terminate: type=%d, layer=%d, code=%d\n",
+ QP_ID(qp),
+ __rdmap_term_etype(&rctx->hdr.terminate),
+ __rdmap_term_layer(&rctx->hdr.terminate),
+ __rdmap_term_ecode(&rctx->hdr.terminate));
+
+ siw_drain_pkt(qp, rctx);
+ return 0;
+}
+
+
+static int siw_get_trailer(struct siw_qp *qp, struct siw_iwarp_rx *rctx)
+{
+ struct sk_buff *skb = rctx->skb;
+ u8 *tbuf = (u8 *)&rctx->trailer.crc - rctx->pad;
+ int avail;
+
+ avail = min(rctx->skb_new, rctx->fpdu_part_rem);
+
+ skb_copy_bits(skb, rctx->skb_offset,
+ tbuf + rctx->fpdu_part_rcvd, avail);
+
+ rctx->fpdu_part_rcvd += avail;
+ rctx->fpdu_part_rem -= avail;
+
+ rctx->skb_new -= avail;
+ rctx->skb_offset += avail;
+ rctx->skb_copied += avail;
+
+ dprint(DBG_RX, " (QP%d): %d remaining (%d)\n", QP_ID(qp),
+ rctx->fpdu_part_rem, avail);
+
+ if (!rctx->fpdu_part_rem) {
+ __be32 crc_in, crc_own = 0;
+ /*
+ * check crc if required
+ */
+ if (!rctx->crc_enabled)
+ return 0;
+
+ if (rctx->pad && siw_crc_array(&rctx->mpa_crc_hd,
+ tbuf, rctx->pad) != 0)
+ return -EINVAL;
+
+ crypto_hash_final(&rctx->mpa_crc_hd, (u8 *)&crc_own);
+
+ /*
+ * CRC32 is computed, transmitted and received directly in NBO,
+ * so there's never a reason to convert byte order.
+ */
+ crc_in = rctx->trailer.crc;
+
+ if (crc_in != crc_own) {
+ dprint(DBG_RX|DBG_ON,
+ " (QP%d): CRC ERROR in:=%08x, own=%08x\n",
+ QP_ID(qp), crc_in, crc_own);
+ return -EINVAL;
+ }
+ return 0;
+ }
+ return -EAGAIN;
+}
+
+
+static int siw_get_hdr(struct siw_iwarp_rx *rctx)
+{
+ struct sk_buff *skb = rctx->skb;
+ struct iwarp_ctrl *c_hdr = &rctx->hdr.ctrl;
+ u8 opcode;
+
+ int bytes;
+
+ if (rctx->fpdu_part_rcvd < sizeof(struct iwarp_ctrl)) {
+ /*
+ * copy first fix part of iwarp hdr
+ */
+ bytes = min_t(int, rctx->skb_new, sizeof(struct iwarp_ctrl)
+ - rctx->fpdu_part_rcvd);
+
+ skb_copy_bits(skb, rctx->skb_offset,
+ (char *)c_hdr + rctx->fpdu_part_rcvd, bytes);
+
+ rctx->fpdu_part_rcvd += bytes;
+
+ rctx->skb_new -= bytes;
+ rctx->skb_offset += bytes;
+ rctx->skb_copied += bytes;
+
+ if (!rctx->skb_new ||
+ rctx->fpdu_part_rcvd < sizeof(struct iwarp_ctrl))
+ return -EAGAIN;
+
+ if (__ddp_version(c_hdr) != DDP_VERSION) {
+ dprint(DBG_RX|DBG_ON, " dversion %d\n",
+ __ddp_version(c_hdr));
+ return -EINVAL;
+ }
+ if (__rdmap_version(c_hdr) != RDMAP_VERSION) {
+ dprint(DBG_RX|DBG_ON, " rversion %d\n",
+ __rdmap_version(c_hdr));
+ return -EINVAL;
+ }
+ opcode = __rdmap_opcode(c_hdr);
+
+ if (opcode > RDMAP_TERMINATE) {
+ dprint(DBG_RX|DBG_ON, " opcode %d\n", opcode);
+ return -EINVAL;
+ }
+ dprint(DBG_RX, "(QP%d): New Header, opcode:%d\n",
+ RX_QPID(rctx), opcode);
+ } else
+ opcode = __rdmap_opcode(c_hdr);
+ /*
+ * figure out len of current hdr: variable length of
+ * iwarp hdr forces us to copy hdr information
+ */
+ bytes = min(rctx->skb_new,
+ iwarp_pktinfo[opcode].hdr_len - rctx->fpdu_part_rcvd);
+
+ skb_copy_bits(skb, rctx->skb_offset,
+ (char *)c_hdr + rctx->fpdu_part_rcvd, bytes);
+
+ rctx->fpdu_part_rcvd += bytes;
+
+ rctx->skb_new -= bytes;
+ rctx->skb_offset += bytes;
+ rctx->skb_copied += bytes;
+
+ if (rctx->fpdu_part_rcvd == iwarp_pktinfo[opcode].hdr_len) {
+ /*
+ * HDR receive completed. Check if the current DDP segment
+ * starts a new RDMAP message or continues a previously
+ * started RDMAP message.
+ *
+ * Note well from the comments on DDP reassembly:
+ * - Support for unordered reception of DDP segments
+ * (or FPDUs) from different RDMAP messages is not needed.
+ * - Unordered reception of DDP segments of the same
+ * RDMAP message is not supported. It is probably not
+ * needed with most peers.
+ */
+ siw_dprint_hdr(&rctx->hdr, RX_QPID(rctx), "HDR received");
+
+ if (rctx->more_ddp_segs != 0) {
+ rctx->first_ddp_seg = 0;
+ if (rctx->prev_rdmap_opcode != opcode) {
+ dprint(DBG_ON,
+ "packet intersection: %d <> %d\n",
+ rctx->prev_rdmap_opcode, opcode);
+ return -EPROTO;
+ }
+ } else {
+ rctx->prev_rdmap_opcode = opcode;
+ rctx->first_ddp_seg = 1;
+ }
+ rctx->more_ddp_segs =
+ c_hdr->ddp_rdmap_ctrl & DDP_FLAG_LAST ? 0 : 1;
+
+ return 0;
+ }
+ return -EAGAIN;
+}
+
+static inline int siw_fpdu_payload_len(struct siw_iwarp_rx *rctx)
+{
+ return be16_to_cpu(rctx->hdr.ctrl.mpa_len) - rctx->fpdu_part_rcvd
+ + MPA_HDR_SIZE;
+}
+
+static inline int siw_fpdu_trailer_len(struct siw_iwarp_rx *rctx)
+{
+ int mpa_len = be16_to_cpu(rctx->hdr.ctrl.mpa_len) + MPA_HDR_SIZE;
+
+ return MPA_CRC_SIZE + (-mpa_len & 0x3);
+}
+
+/*
+ * siw_rreq_complete()
+ *
+ * Complete the current READ REQUEST after READ RESPONSE processing.
+ * It may complete consecutive WQE's which were already SQ
+ * processed before but are awaiting completion due to completion
+ * ordering (see verbs 8.2.2.2).
+ * The READ RESPONSE may also resume SQ processing if it was stalled
+ * due to ORD exhaustion (see verbs 8.2.2.18)
+ * Function stops completion when next READ REQUEST found or ORQ empty.
+ */
+static void siw_rreq_complete(struct siw_wqe *wqe, int error)
+{
+ struct siw_qp *qp = wqe->qp;
+ int num_wc = 1;
+ enum ib_send_flags flags;
+ LIST_HEAD(c_list);
+
+ flags = wr_flags(wqe);
+
+ if (flags & IB_SEND_SIGNALED)
+ list_add(&wqe->list, &c_list);
+ else {
+ atomic_inc(&qp->sq_space);
+ siw_wqe_put(wqe);
+ num_wc = 0;
+ }
+
+ lock_orq(qp);
+
+ /* More WQE's to complete following this RREQ? */
+ if (!list_empty(&qp->orq)) {
+ struct list_head *pos, *n;
+ list_for_each_safe(pos, n, &qp->orq) {
+ wqe = list_entry_wqe(pos);
+ if (wr_type(wqe) == SIW_WR_RDMA_READ_REQ)
+ break;
+ flags |= wr_flags(wqe);
+ num_wc++;
+ dprint(DBG_WR|DBG_ON,
+ "(QP%d): Resume completion, wr_type %d\n",
+ QP_ID(qp), wr_type(wqe));
+ list_move_tail(pos, &c_list);
+ }
+ }
+ unlock_orq(qp);
+
+ if (num_wc)
+ siw_sq_complete(&c_list, qp, num_wc, flags);
+
+ /*
+ * Check if SQ processing was stalled due to ORD limit
+ */
+ if (ORD_SUSPEND_SQ(qp)) {
+ lock_sq(qp);
+
+ wqe = siw_next_tx_wqe(qp);
+
+ if (wqe && !tx_wqe(qp)) {
+ WARN_ON(wr_type(wqe) != SIW_WR_RDMA_READ_REQ);
+ list_del_init(&wqe->list);
+ tx_wqe(qp) = wqe;
+
+ list_add_tail(&wqe->list, &qp->orq);
+
+ unlock_sq(qp);
+
+ dprint(DBG_RX, "(QP%d): SQ resume (%d)\n",
+ QP_ID(qp), atomic_read(&qp->sq_space));
+
+ siw_sq_queue_work(qp);
+ } else {
+ /* only new ORQ space if not next RREQ queued */
+ atomic_inc(&qp->orq_space);
+ unlock_sq(qp);
+ }
+ } else
+ atomic_inc(&qp->orq_space);
+}
+
+/*
+ * siw_rdmap_complete()
+ *
+ * complete processing of an RDMA message after receiving all
+ * DDP segmens
+ *
+ * o SENDs + RRESPs will need for completion,
+ * o RREQs need for READ RESPONSE initialization
+ * o WRITEs need memory dereferencing
+ *
+ * TODO: Could siw_[s,r]_complete() fail? (CQ full)
+ */
+static inline int siw_rdmap_complete(struct siw_qp *qp,
+ struct siw_iwarp_rx *rctx)
+{
+ struct siw_wqe *wqe;
+ u8 opcode = __rdmap_opcode(&rctx->hdr.ctrl);
+ int rv = 0;
+
+ switch (opcode) {
+
+ case RDMAP_SEND_SE:
+ wr_flags(rx_wqe(qp)) |= IB_SEND_SOLICITED;
+ case RDMAP_SEND:
+ rctx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]++;
+
+ wqe = rx_wqe(qp);
+
+ wqe->wc_status = IB_WC_SUCCESS;
+ wqe->wr_status = SR_WR_DONE;
+
+ siw_rq_complete(wqe, qp);
+
+ break;
+
+ case RDMAP_RDMA_READ_RESP:
+ rctx->ddp_msn[RDMAP_UNTAGGED_QN_RDMA_READ]++;
+
+ wqe = rx_wqe(qp);
+
+ wqe->wc_status = IB_WC_SUCCESS;
+ wqe->wr_status = SR_WR_DONE;
+
+ siw_rreq_complete(wqe, 0);
+
+ break;
+
+ case RDMAP_RDMA_READ_REQ:
+ rv = siw_init_rresp(qp, rctx);
+
+ break;
+
+ case RDMAP_RDMA_WRITE:
+ /*
+ * Free References from memory object if
+ * attached to receive context (inbound WRITE)
+ * While a zero-length WRITE is allowed, the
+ * current implementation does not create
+ * a memory reference (it is unclear if memory
+ * rights should be checked in that case!).
+ *
+ * TODO: check zero length WRITE semantics
+ */
+ if (rx_mem(qp))
+ siw_mem_put(rx_mem(qp));
+ break;
+
+ default:
+ break;
+
+ }
+ rctx->umem_chunk = NULL; /* DEBUG aid, tentatively */
+ rx_wqe(qp) = NULL; /* also clears MEM object for WRITE */
+
+ return rv;
+}
+
+/*
+ * siw_rdmap_error()
+ *
+ * Abort processing of RDMAP message after failure.
+ * SENDs + RRESPs will need for receive completion, if
+ * already started.
+ *
+ * TODO: WRITE need local error to be surfaced.
+ *
+ */
+static inline void
+siw_rdmap_error(struct siw_qp *qp, struct siw_iwarp_rx *rctx, int status)
+{
+ struct siw_wqe *wqe;
+ u8 opcode = __rdmap_opcode(&rctx->hdr.ctrl);
+
+ switch (opcode) {
+
+ case RDMAP_SEND_SE:
+ case RDMAP_SEND:
+ rctx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]++;
+
+ wqe = rx_wqe(qp);
+ if (!wqe)
+ return;
+
+ if (opcode == RDMAP_SEND_SE)
+ wr_flags(wqe) |= IB_SEND_SOLICITED;
+
+ if (!wqe->wc_status)
+ wqe->wc_status = IB_WC_GENERAL_ERR;
+
+ wqe->wr_status = SR_WR_DONE;
+ siw_rq_complete(wqe, qp);
+
+ break;
+
+ case RDMAP_RDMA_READ_RESP:
+ /*
+ * A READ RESPONSE may flush consecutive WQE's
+ * which were SQ processed before
+ */
+ rctx->ddp_msn[RDMAP_UNTAGGED_QN_RDMA_READ]++;
+
+ if (rctx->state == SIW_GET_HDR || status == -ENODATA)
+ /* eventual RREQ left untouched */
+ break;
+
+ wqe = rx_wqe(qp);
+ if (wqe) {
+ if (status)
+ wqe->wc_status = status;
+ else
+ wqe->wc_status = IB_WC_GENERAL_ERR;
+
+ wqe->wr_status = SR_WR_DONE;
+ /*
+ * All errors turn the wqe into signalled.
+ */
+ wr_flags(wqe) |= IB_SEND_SIGNALED;
+ siw_rreq_complete(wqe, status);
+ }
+ break;
+
+ case RDMAP_RDMA_WRITE:
+ /*
+ * Free References from memory object if
+ * attached to receive context (inbound WRITE)
+ * While a zero-length WRITE is allowed, the
+ * current implementation does not create
+ * a memory reference (it is unclear if memory
+ * rights should be checked in that case!).
+ *
+ * TODO: check zero length WRITE semantics
+ */
+ if (rx_mem(qp))
+ siw_mem_put(rx_mem(qp));
+ break;
+
+ default:
+ break;
+ }
+ rctx->umem_chunk = NULL; /* DEBUG aid, tentatively */
+ rx_wqe(qp) = NULL; /* also clears MEM object for WRITE */
+}
+
+/*
+ * siw_tcp_rx_data()
+ *
+ * Main routine to consume inbound TCP payload
+ *
+ * @rd_desc: read descriptor
+ * @skb: socket buffer
+ * @off: offset in skb
+ * @len: skb->len - offset : payload in skb
+ */
+int siw_tcp_rx_data(read_descriptor_t *rd_desc, struct sk_buff *skb,
+ unsigned int off, size_t len)
+{
+ struct siw_qp *qp = rd_desc->arg.data;
+ struct siw_iwarp_rx *rctx = &qp->rx_ctx;
+ int rv;
+
+ rctx->skb = skb;
+ rctx->skb_new = skb->len - off;
+ rctx->skb_offset = off;
+ rctx->skb_copied = 0;
+
+ dprint(DBG_RX, "(QP%d): new data %d, rx-state %d\n", QP_ID(qp),
+ rctx->skb_new, rctx->state);
+
+ if (unlikely(rctx->rx_suspend == 1 ||
+ qp->attrs.state != SIW_QP_STATE_RTS)) {
+ dprint(DBG_RX|DBG_ON, "(QP%d): failed. state rx:%d, qp:%d\n",
+ QP_ID(qp), qp->rx_ctx.state, qp->attrs.state);
+ return 0;
+ }
+ while (rctx->skb_new) {
+
+ switch (rctx->state) {
+
+ case SIW_GET_HDR:
+ rv = siw_get_hdr(rctx);
+ if (!rv) {
+ if (rctx->crc_enabled &&
+ siw_crc_rxhdr(rctx) != 0) {
+ rv = -EINVAL;
+ break;
+ }
+ rctx->fpdu_part_rem =
+ siw_fpdu_payload_len(rctx);
+
+ if (rctx->fpdu_part_rem)
+ rctx->pad = -rctx->fpdu_part_rem & 0x3;
+ else
+ rctx->pad = 0;
+
+ rctx->state = SIW_GET_DATA_START;
+ rctx->fpdu_part_rcvd = 0;
+ }
+ break;
+
+ case SIW_GET_DATA_MORE:
+ /*
+ * Another data fragment of the same DDP segment.
+ * Headers will not be checked again by the
+ * opcode-specific data receive function below.
+ * Setting first_ddp_seg = 0 avoids repeating
+ * initializations that may occur only once per
+ * DDP segment.
+ */
+ rctx->first_ddp_seg = 0;
+
+ case SIW_GET_DATA_START:
+ /*
+ * Headers will be checked by the opcode-specific
+ * data receive function below.
+ */
+ rv = siw_rx_data(qp, rctx);
+ if (!rv) {
+ rctx->fpdu_part_rem =
+ siw_fpdu_trailer_len(rctx);
+ rctx->fpdu_part_rcvd = 0;
+ rctx->state = SIW_GET_TRAILER;
+ } else
+ rctx->state = SIW_GET_DATA_MORE;
+
+ break;
+
+ case SIW_GET_TRAILER:
+ /*
+ * read CRC + any padding
+ */
+ rv = siw_get_trailer(qp, rctx);
+ if (!rv) {
+ /*
+ * FPDU completed.
+ * complete RDMAP message if last fragment
+ */
+ rctx->state = SIW_GET_HDR;
+ rctx->fpdu_part_rcvd = 0;
+
+ if (!(rctx->hdr.ctrl.ddp_rdmap_ctrl
+ & DDP_FLAG_LAST))
+ /* more frags */
+ break;
+
+ rv = siw_rdmap_complete(qp, rctx);
+ if (rv)
+ break;
+ }
+ break;
+
+ default:
+ WARN_ON(1);
+ rv = -EAGAIN;
+ }
+
+ if (unlikely(rv != 0 && rv != -EAGAIN)) {
+ /*
+ * TODO: implement graceful error handling including
+ * generation (and processing) of TERMINATE
+ * messages.
+ *
+ * for now we are left with a bogus rx status
+ * unable to receive any further byte.
+ * BUT: code must handle difference between
+ *
+ * o protocol syntax (FATAL, framing lost)
+ * o crc (FATAL, framing lost since we do not
+ * trust packet header (??))
+ * o local resource (maybe non fatal, framing
+ * not lost)
+ *
+ * errors.
+ */
+ siw_rdmap_error(qp, rctx, rv);
+
+ dprint(DBG_RX|DBG_ON,
+ "(QP%d): RX ERROR %d at RX state %d\n",
+ QP_ID(qp), rv, rctx->state);
+
+ siw_dprint_rctx(rctx);
+ /*
+ * Calling siw_cm_queue_work() is safe without
+ * releasing qp->state_lock because the QP state
+ * will be transitioned to SIW_QP_STATE_ERROR
+ * by the siw_work_handler() workqueue handler
+ * after we return from siw_qp_llp_data_ready().
+ */
+ siw_qp_cm_drop(qp, 1);
+
+ break;
+ }
+ if (rv) {
+ dprint(DBG_RX, "(QP%d): "
+ "Misaligned FPDU: State: %d, missing: %d\n",
+ QP_ID(qp), rctx->state, rctx->fpdu_part_rem);
+ break;
+ }
+ }
+ return rctx->skb_copied;
+}