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Message-Id: <1308228153-22720-1-git-send-email-bmt@zurich.ibm.com>
Date: Thu, 16 Jun 2011 14:42:33 +0200
From: Bernard Metzler <bmt@...ich.ibm.com>
To: netdev@...r.kernel.org
Cc: linux-rdma@...r.kernel.org, Bernard Metzler <bmt@...ich.ibm.com>
Subject: [PATCH 10/14] SIWv2: Transmit path: siw_qp_tx.c
---
drivers/infiniband/hw/siw/siw_qp_tx.c | 1332 +++++++++++++++++++++++++++++++++
1 files changed, 1332 insertions(+), 0 deletions(-)
create mode 100644 drivers/infiniband/hw/siw/siw_qp_tx.c
diff --git a/drivers/infiniband/hw/siw/siw_qp_tx.c b/drivers/infiniband/hw/siw/siw_qp_tx.c
new file mode 100644
index 0000000..54e0037
--- /dev/null
+++ b/drivers/infiniband/hw/siw/siw_qp_tx.c
@@ -0,0 +1,1332 @@
+/*
+ * Software iWARP device driver for Linux
+ *
+ * Authors: Bernard Metzler <bmt@...ich.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"
+
+static bool zcopy_tx = 1;
+module_param(zcopy_tx, bool, 0644);
+MODULE_PARM_DESC(zcopy_tx, "Zero copy user data transmit if possible");
+
+static DEFINE_PER_CPU(atomic_t, siw_workq_len);
+
+static inline int siw_crc_txhdr(struct siw_iwarp_tx *ctx)
+{
+ crypto_hash_init(&ctx->mpa_crc_hd);
+ return siw_crc_array(&ctx->mpa_crc_hd, (u8 *)&ctx->pkt,
+ ctx->ctrl_len);
+}
+
+#define PKT_FRAGMENTED 1
+#define PKT_COMPLETE 0
+
+/*
+ * siw_qp_prepare_tx()
+ *
+ * Prepare tx state for sending out one fpdu. Builds complete pkt
+ * if no user data or only immediate data are present.
+ *
+ * returns PKT_COMPLETE if complete pkt built, PKT_FRAGMENTED otherwise.
+ */
+static int siw_qp_prepare_tx(struct siw_iwarp_tx *c_tx)
+{
+ struct siw_wqe *wqe = c_tx->wqe;
+ u32 *crc = NULL;
+
+ dprint(DBG_TX, "(QP%d):\n", TX_QPID(c_tx));
+
+ switch (wr_type(wqe)) {
+
+ case SIW_WR_RDMA_READ_REQ:
+ memcpy(&c_tx->pkt.ctrl,
+ &iwarp_pktinfo[RDMAP_RDMA_READ_REQ].ctrl,
+ sizeof(struct iwarp_ctrl));
+
+ c_tx->pkt.rreq.rsvd = 0;
+ c_tx->pkt.rreq.ddp_qn = htonl(RDMAP_UNTAGGED_QN_RDMA_READ);
+ c_tx->pkt.rreq.ddp_msn =
+ htonl(++c_tx->ddp_msn[RDMAP_UNTAGGED_QN_RDMA_READ]);
+ c_tx->pkt.rreq.ddp_mo = 0;
+ c_tx->pkt.rreq.sink_stag = htonl(wqe->wr.rread.sge[0].lkey);
+ c_tx->pkt.rreq.sink_to =
+ cpu_to_be64(wqe->wr.rread.sge[0].addr); /* abs addr! */
+ c_tx->pkt.rreq.source_stag = htonl(wqe->wr.rread.rtag);
+ c_tx->pkt.rreq.source_to = cpu_to_be64(wqe->wr.rread.raddr);
+ c_tx->pkt.rreq.read_size = htonl(wqe->bytes);
+
+ dprint(DBG_TX, ": RREQ: Sink: %x, 0x%016llx\n",
+ wqe->wr.rread.sge[0].lkey, wqe->wr.rread.sge[0].addr);
+
+ c_tx->ctrl_len = sizeof(struct iwarp_rdma_rreq);
+ crc = &c_tx->pkt.rreq_pkt.crc;
+ break;
+
+ case SIW_WR_SEND:
+ if (wr_flags(wqe) & IB_SEND_SOLICITED)
+ memcpy(&c_tx->pkt.ctrl,
+ &iwarp_pktinfo[RDMAP_SEND_SE].ctrl,
+ sizeof(struct iwarp_ctrl));
+ else
+ memcpy(&c_tx->pkt.ctrl,
+ &iwarp_pktinfo[RDMAP_SEND].ctrl,
+ sizeof(struct iwarp_ctrl));
+
+ c_tx->pkt.send.ddp_qn = RDMAP_UNTAGGED_QN_SEND;
+ c_tx->pkt.send.ddp_msn =
+ htonl(++c_tx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]);
+ c_tx->pkt.send.ddp_mo = 0;
+ c_tx->pkt.send.rsvd = 0;
+
+ c_tx->ctrl_len = sizeof(struct iwarp_send);
+
+ if (!wqe->bytes)
+ crc = &c_tx->pkt.send_pkt.crc;
+ break;
+
+ case SIW_WR_RDMA_WRITE:
+ memcpy(&c_tx->pkt.ctrl, &iwarp_pktinfo[RDMAP_RDMA_WRITE].ctrl,
+ sizeof(struct iwarp_ctrl));
+
+ c_tx->pkt.rwrite.sink_stag = htonl(wqe->wr.write.rtag);
+ c_tx->pkt.rwrite.sink_to = cpu_to_be64(wqe->wr.write.raddr);
+ c_tx->ctrl_len = sizeof(struct iwarp_rdma_write);
+
+ if (!wqe->bytes)
+ crc = &c_tx->pkt.write_pkt.crc;
+ break;
+
+ case SIW_WR_RDMA_READ_RESP:
+ memcpy(&c_tx->pkt.ctrl,
+ &iwarp_pktinfo[RDMAP_RDMA_READ_RESP].ctrl,
+ sizeof(struct iwarp_ctrl));
+
+ /* NBO */
+ c_tx->pkt.rresp.sink_stag = wqe->wr.rresp.rtag;
+ c_tx->pkt.rresp.sink_to = cpu_to_be64(wqe->wr.rresp.raddr);
+
+ c_tx->ctrl_len = sizeof(struct iwarp_rdma_rresp);
+
+ dprint(DBG_TX, ": RRESP: Sink: %x, 0x%016llx\n",
+ wqe->wr.rresp.rtag, wqe->wr.rresp.raddr);
+
+ if (!wqe->bytes)
+ crc = &c_tx->pkt.rresp_pkt.crc;
+ break;
+
+ default:
+ dprint(DBG_ON, "Unsupported WQE type %d\n", wr_type(wqe));
+ BUG();
+ break;
+ }
+ c_tx->ctrl_sent = 0;
+ c_tx->sge_idx = 0;
+ c_tx->sge_off = 0;
+ c_tx->pg_idx = 0;
+ c_tx->umem_chunk = NULL;
+
+ /*
+ * Do complete CRC if enabled and short packet
+ */
+ if (crc) {
+ *crc = 0;
+ if (c_tx->crc_enabled) {
+ if (siw_crc_txhdr(c_tx) != 0)
+ return -EINVAL;
+ crypto_hash_final(&c_tx->mpa_crc_hd, (u8 *)crc);
+ }
+ }
+ c_tx->ctrl_len += MPA_CRC_SIZE;
+
+ /*
+ * Allow direct sending out of user buffer if WR is non signalled
+ * and payload is over threshold and no CRC is enabled.
+ * Per RDMA verbs, the application should not change the send buffer
+ * until the work completed. In iWarp, work completion is only
+ * local delivery to TCP. TCP may reuse the buffer for
+ * retransmission. Changing unsent data also breaks the CRC,
+ * if applied.
+ * Inline buffers are already out of user control and can be
+ * send 0copy.
+ */
+ if (zcopy_tx &&
+ (!(wr_flags(wqe) & IB_SEND_SIGNALED) || SIW_INLINED_DATA(wqe)) &&
+ wqe->bytes > SENDPAGE_THRESH &&
+ wr_type(wqe) != SIW_WR_RDMA_READ_REQ)
+ c_tx->use_sendpage = 1;
+ else
+ c_tx->use_sendpage = 0;
+
+ return crc == NULL ? PKT_FRAGMENTED : PKT_COMPLETE;
+}
+
+/*
+ * Send out one complete FPDU. Used for fixed sized packets like
+ * Read Requests or zero length SENDs, WRITEs, READ.responses.
+ * Also used for pushing an FPDU hdr only.
+ */
+static inline int siw_tx_ctrl(struct siw_iwarp_tx *c_tx, struct socket *s,
+ int flags)
+{
+ struct msghdr msg = {.msg_flags = flags};
+ struct kvec iov = {
+ .iov_base = (char *)&c_tx->pkt.ctrl + c_tx->ctrl_sent,
+ .iov_len = c_tx->ctrl_len - c_tx->ctrl_sent};
+
+ int rv = kernel_sendmsg(s, &msg, &iov, 1,
+ c_tx->ctrl_len - c_tx->ctrl_sent);
+
+ dprint(DBG_TX, " (QP%d): op=%d, %d of %d sent (%d)\n",
+ TX_QPID(c_tx), c_tx->pkt.ctrl.opcode,
+ c_tx->ctrl_sent + rv, c_tx->ctrl_len, rv);
+
+ if (rv >= 0) {
+ c_tx->ctrl_sent += rv;
+
+ if (c_tx->ctrl_sent == c_tx->ctrl_len) {
+ siw_dprint_hdr(&c_tx->pkt.hdr, TX_QPID(c_tx),
+ "CTRL sent");
+ if (!(flags & MSG_MORE))
+ c_tx->new_tcpseg = 1;
+ rv = 0;
+ } else if (c_tx->ctrl_sent < c_tx->ctrl_len)
+ rv = -EAGAIN;
+ else
+ BUG();
+ }
+ return rv;
+}
+
+/*
+ * 0copy TCP transmit interface.
+ *
+ * Push page array page by page or in one shot.
+ * Pushing the whole page array requires the inner do_tcp_sendpages
+ * function to be exported by the kernel.
+ */
+static int siw_tcp_sendpages(struct socket *s, struct page **page,
+ int offset, size_t size)
+{
+ int rv = 0;
+
+#ifdef SIW_SENDPAGES_EXPORT
+ struct sock *sk = s->sk;
+
+ if (!(sk->sk_route_caps & NETIF_F_SG) ||
+ !(sk->sk_route_caps & NETIF_F_ALL_CSUM)) {
+ /* FIXME:
+ * This should also be handled in a
+ * loop
+ */
+ return -EFAULT;
+ }
+
+ lock_sock(sk);
+ TCP_CHECK_TIMER(sk);
+
+ /*
+ * just return what sendpages has return
+ */
+ rv = do_tcp_sendpages(sk, page, offset, size, MSG_MORE|MSG_DONTWAIT);
+
+ TCP_CHECK_TIMER(sk);
+ release_sock(sk);
+ if (rv == -EAGAIN)
+ rv = 0;
+#else
+ /*
+ * If do_tcp_sendpages() function is not exported
+ * push page by page
+ */
+ size_t todo = size;
+ int i;
+
+ for (i = 0; size > 0; i++) {
+ size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);
+
+ rv = s->ops->sendpage(s, page[i], offset, bytes,
+ MSG_MORE|MSG_DONTWAIT);
+ if (rv <= 0)
+ break;
+
+ size -= rv;
+
+ if (rv != bytes)
+ break;
+
+ offset = 0;
+ }
+ if (rv >= 0 || rv == -EAGAIN)
+ rv = todo - size;
+#endif
+ return rv;
+}
+
+/*
+ * siw_0copy_tx()
+ *
+ * Pushes list of pages to TCP socket. If pages from multiple
+ * SGE's, all referenced pages of each SGE are pushed in one
+ * shot.
+ */
+static int siw_0copy_tx(struct socket *s, struct page **page,
+ struct siw_sge *sge, unsigned int offset,
+ unsigned int size)
+{
+ int i = 0, sent = 0, rv;
+ int sge_bytes = min(sge->len - offset, size);
+
+ offset = (sge->addr + offset) & ~PAGE_MASK;
+
+ while (sent != size) {
+
+ rv = siw_tcp_sendpages(s, &page[i], offset, sge_bytes);
+ if (rv >= 0) {
+ sent += rv;
+ if (size == sent || sge_bytes > rv)
+ break;
+
+ i += PAGE_ALIGN(sge_bytes + offset) >> PAGE_SHIFT;
+ sge++;
+ sge_bytes = min(sge->len, size - sent);
+ offset = sge->addr & ~PAGE_MASK;
+ } else {
+ sent = rv;
+ break;
+ }
+ }
+ return sent;
+}
+
+/*
+ * siw_tx_umem_init()
+ *
+ * Resolve memory chunk and update page index pointer
+ *
+ * @chunk: Umem Chunk to be updated
+ * @p_idx Page Index to be updated
+ * @mr: Memory Region
+ * @va: Virtual Address within MR
+ *
+ */
+static void siw_tx_umem_init(struct ib_umem_chunk **chunk, int *page_index,
+ struct siw_mr *mr, u64 va)
+{
+ struct ib_umem_chunk *cp;
+ int p_ix;
+
+ BUG_ON(va < mr->mem.va);
+ va -= mr->mem.va & PAGE_MASK;
+ /*
+ * equivalent to
+ * va += mr->umem->offset;
+ * va = va >> PAGE_SHIFT;
+ */
+
+ p_ix = va >> PAGE_SHIFT;
+
+ list_for_each_entry(cp, &mr->umem->chunk_list, list) {
+ if (p_ix < cp->nents)
+ break;
+ p_ix -= cp->nents;
+ }
+ BUG_ON(p_ix >= cp->nents);
+
+ dprint(DBG_MM, "(): New chunk 0x%p: Page idx %d, nents %d\n",
+ cp, p_ix, cp->nents);
+
+ *chunk = cp;
+ *page_index = p_ix;
+
+ return;
+}
+
+/*
+ * update memory chunk and page index from given starting point
+ * before current transmit described by: c_tx->sge_off,
+ * sge->addr, c_tx->pg_idx, and c_tx->umem_chunk
+ */
+static inline void
+siw_umem_chunk_update(struct siw_iwarp_tx *c_tx, struct siw_mr *mr,
+ struct siw_sge *sge, unsigned int off)
+{
+ struct ib_umem_chunk *chunk = c_tx->umem_chunk;
+ u64 va_start = sge->addr + c_tx->sge_off;
+
+ off += (unsigned int)(va_start & ~PAGE_MASK); /* + first page offset */
+ off >>= PAGE_SHIFT; /* bytes offset becomes pages offset */
+
+ list_for_each_entry_from(chunk, &mr->umem->chunk_list, list) {
+ if (c_tx->pg_idx + off < chunk->nents)
+ break;
+ off -= chunk->nents - c_tx->pg_idx;
+ c_tx->pg_idx = 0;
+ }
+ c_tx->pg_idx += off;
+
+ c_tx->umem_chunk = chunk;
+}
+
+#define MAX_TRAILER (MPA_CRC_SIZE + 4)
+#define MAX_ARRAY 32 /* Max number of kernel_sendmsg elements */
+
+static inline void
+siw_save_txstate(struct siw_iwarp_tx *c_tx, struct ib_umem_chunk *chunk,
+ unsigned int pg_idx, unsigned int sge_idx,
+ unsigned int sge_off)
+{
+ c_tx->umem_chunk = chunk;
+ c_tx->pg_idx = pg_idx;
+ c_tx->sge_idx = sge_idx;
+ c_tx->sge_off = sge_off;
+}
+/*
+ * Write out iov referencing hdr, data and trailer of current FPDU.
+ * Update transmit state dependent on write return status
+ */
+static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
+{
+ struct siw_wqe *wqe = c_tx->wqe;
+ struct siw_sge *sge = &wqe->wr.sgl.sge[c_tx->sge_idx],
+ *first_sge = sge;
+ struct siw_mr *mr = NULL;
+ struct ib_umem_chunk *chunk = c_tx->umem_chunk;
+
+ struct kvec iov[MAX_ARRAY];
+ struct page *page_array[MAX_ARRAY];
+ struct msghdr msg = {.msg_flags = MSG_DONTWAIT};
+
+ int seg = 0, do_crc = c_tx->do_crc, is_kva = 0, rv;
+ unsigned int data_len = c_tx->bytes_unsent,
+ hdr_len = 0,
+ trl_len = 0,
+ sge_off = c_tx->sge_off,
+ sge_idx = c_tx->sge_idx,
+ pg_idx = c_tx->pg_idx;
+
+
+ if (c_tx->state == SIW_SEND_HDR) {
+ if (c_tx->use_sendpage) {
+ rv = siw_tx_ctrl(c_tx, s, MSG_DONTWAIT|MSG_MORE);
+ if (rv)
+ goto done;
+
+ c_tx->state = SIW_SEND_DATA;
+ } else {
+ iov[0].iov_base =
+ (char *)&c_tx->pkt.ctrl + c_tx->ctrl_sent;
+ iov[0].iov_len = hdr_len =
+ c_tx->ctrl_len - c_tx->ctrl_sent;
+ seg = 1;
+ siw_dprint_hdr(&c_tx->pkt.hdr, TX_QPID(c_tx),
+ "HDR to send: ");
+ }
+ }
+
+ wqe->processed += data_len;
+
+ while (data_len) { /* walk the list of SGE's */
+ unsigned int sge_len = min(sge->len - sge_off, data_len);
+ unsigned int fp_off = (sge->addr + sge_off) & ~PAGE_MASK;
+
+ BUG_ON(!sge_len);
+
+ if (!SIW_INLINED_DATA(wqe)) {
+ mr = siw_mem2mr(sge->mem.obj);
+ if (!mr->umem)
+ is_kva = 1;
+ else if (!chunk) {
+ siw_tx_umem_init(&chunk, &pg_idx, mr,
+ sge->addr + sge_off);
+
+ if (!c_tx->umem_chunk)
+ /* Starting first tx for this WQE */
+ siw_save_txstate(c_tx, chunk, pg_idx,
+ sge_idx, sge_off);
+ }
+ } else
+ is_kva = 1;
+
+ if (is_kva && !c_tx->use_sendpage) {
+ /*
+ * tx from kernel virtual address: either inline data
+ * or memory region with assigned kernel buffer
+ */
+ iov[seg].iov_base = (void *)(sge->addr + sge_off);
+ iov[seg].iov_len = sge_len;
+
+ if (do_crc)
+ siw_crc_array(&c_tx->mpa_crc_hd,
+ iov[seg].iov_base, sge_len);
+ sge_off += sge_len;
+ data_len -= sge_len;
+ seg++;
+ goto sge_done;
+ }
+
+ while (sge_len) {
+ struct scatterlist *sl;
+ size_t plen = min((int)PAGE_SIZE - fp_off, sge_len);
+
+ BUG_ON(plen <= 0);
+ if (!is_kva) {
+ sl = &chunk->page_list[pg_idx];
+ page_array[seg] = sg_page(sl);
+ if (!c_tx->use_sendpage) {
+ iov[seg].iov_base = kmap(sg_page(sl))
+ + fp_off;
+ iov[seg].iov_len = plen;
+ }
+ if (do_crc)
+ siw_crc_sg(&c_tx->mpa_crc_hd, sl,
+ fp_off, plen);
+ } else {
+ u64 pa = ((sge->addr + sge_off) & PAGE_MASK);
+ page_array[seg] = virt_to_page(pa);
+ if (do_crc)
+ siw_crc_array(&c_tx->mpa_crc_hd,
+ (void *)(sge->addr + sge_off),
+ plen);
+ }
+
+ sge_len -= plen;
+ sge_off += plen;
+ data_len -= plen;
+
+ if (!is_kva && plen + fp_off == PAGE_SIZE &&
+ sge_off < sge->len && ++pg_idx == chunk->nents) {
+ chunk = mem_chunk_next(chunk);
+ pg_idx = 0;
+ }
+ fp_off = 0;
+ if (++seg > MAX_ARRAY) {
+ int i = (hdr_len > 0) ? 1 : 0;
+
+ dprint(DBG_ON, "(QP%d): Too many fragments\n",
+ TX_QPID(c_tx));
+ if (!is_kva) {
+ seg--;
+ while (i < seg)
+ kunmap(page_array[i++]);
+ }
+ wqe->processed = 0;
+ rv = -EINVAL;
+ goto done_crc;
+ }
+ }
+sge_done:
+ /* Update SGE variables at end of SGE */
+ if (sge_off == sge->len &&
+ (data_len != 0 || wqe->processed < wqe->bytes)) {
+ sge_idx++;
+ sge++;
+ sge_off = 0;
+ chunk = NULL;
+ }
+ }
+ /* trailer */
+ if (likely(c_tx->state != SIW_SEND_TRAILER)) {
+ iov[seg].iov_base = &c_tx->trailer.pad[4 - c_tx->pad];
+ iov[seg].iov_len = trl_len = MAX_TRAILER - (4 - c_tx->pad);
+ } else {
+ iov[seg].iov_base = &c_tx->trailer.pad[c_tx->ctrl_sent];
+ iov[seg].iov_len = trl_len = MAX_TRAILER - c_tx->ctrl_sent;
+ }
+
+ if (c_tx->pad) {
+ *(u32 *)c_tx->trailer.pad = 0;
+ if (do_crc)
+ siw_crc_array(&c_tx->mpa_crc_hd,
+ (u8 *)&c_tx->trailer.crc - c_tx->pad,
+ c_tx->pad);
+ }
+ if (!c_tx->crc_enabled)
+ c_tx->trailer.crc = 0;
+ else if (do_crc)
+ crypto_hash_final(&c_tx->mpa_crc_hd, (u8 *)&c_tx->trailer.crc);
+
+ data_len = c_tx->bytes_unsent;
+
+ if (c_tx->tcp_seglen >= (int)MPA_MIN_FRAG &&
+ TX_MORE_WQE(TX_QP(c_tx))) {
+ msg.msg_flags |= MSG_MORE;
+ c_tx->new_tcpseg = 0;
+ } else
+ c_tx->new_tcpseg = 1;
+
+ if (c_tx->use_sendpage) {
+ rv = siw_0copy_tx(s, page_array, first_sge, c_tx->sge_off,
+ data_len);
+ if (rv == data_len) {
+ rv = kernel_sendmsg(s, &msg, &iov[seg], 1, trl_len);
+ if (rv > 0)
+ rv += data_len;
+ else
+ rv = data_len;
+ }
+ } else {
+ rv = kernel_sendmsg(s, &msg, iov, seg + 1,
+ hdr_len + data_len + trl_len);
+ if (!is_kva) {
+ int i = (hdr_len > 0) ? 1 : 0;
+ while (i < seg)
+ kunmap(page_array[i++]);
+ }
+ }
+ if (rv < (int)hdr_len) {
+ /* Not even complete hdr pushed or negative rv */
+ wqe->processed -= data_len;
+ if (rv >= 0) {
+ c_tx->ctrl_sent += rv;
+ rv = -EAGAIN;
+ }
+ goto done_crc;
+ }
+
+ rv -= hdr_len;
+
+ if (rv >= (int)data_len) {
+ /* all user data pushed to TCP or no data to push */
+ if (data_len > 0 && wqe->processed < wqe->bytes)
+ /* Save the current state for next tx */
+ siw_save_txstate(c_tx, chunk, pg_idx, sge_idx,
+ sge_off);
+
+ rv -= data_len;
+
+ if (rv == trl_len) /* all pushed */
+ rv = 0;
+ else {
+ c_tx->state = SIW_SEND_TRAILER;
+ c_tx->ctrl_len = MAX_TRAILER;
+ c_tx->ctrl_sent = rv + 4 - c_tx->pad;
+ c_tx->bytes_unsent = 0;
+ rv = -EAGAIN;
+ }
+
+ } else if (data_len > 0) {
+ /* Maybe some user data pushed to TCP */
+ c_tx->state = SIW_SEND_DATA;
+ wqe->processed -= data_len - rv;
+
+ if (rv) {
+ /*
+ * Some bytes out. Recompute tx state based
+ * on old state and bytes pushed
+ */
+ c_tx->bytes_unsent -= rv;
+ sge = &wqe->wr.sgl.sge[c_tx->sge_idx];
+
+ if (!is_kva && c_tx->sge_idx == sge_idx &&
+ c_tx->umem_chunk)
+ /*
+ * same SGE as starting SGE for this FPDU
+ */
+ siw_umem_chunk_update(c_tx, mr, sge, rv);
+ else {
+ while (sge->len <= c_tx->sge_off + rv) {
+ rv -= sge->len - c_tx->sge_off;
+ c_tx->sge_idx++;
+ c_tx->sge_off = 0;
+ sge = &wqe->wr.sgl.sge[c_tx->sge_idx];
+ }
+ c_tx->umem_chunk = NULL;
+ }
+ c_tx->sge_off += rv;
+ BUG_ON(c_tx->sge_off >= sge->len);
+ }
+ rv = -EAGAIN;
+ }
+done_crc:
+ c_tx->do_crc = 0;
+done:
+ return rv;
+}
+
+static void siw_calculate_tcpseg(struct siw_iwarp_tx *c_tx, struct socket *s)
+{
+ /*
+ * refresh TCP segement len if we start a new segment or
+ * remaining segment len is less than MPA_MIN_FRAG or
+ * the socket send buffer is empty.
+ */
+ if (c_tx->new_tcpseg || c_tx->tcp_seglen < (int)MPA_MIN_FRAG ||
+ !tcp_send_head(s->sk))
+
+ c_tx->tcp_seglen = get_tcp_mss(s->sk);
+}
+
+
+/*
+ * siw_unseg_txlen()
+ *
+ * Compute complete tcp payload len if packet would not
+ * get fragmented
+ */
+static inline int siw_unseg_txlen(struct siw_iwarp_tx *c_tx)
+{
+ int pad = c_tx->bytes_unsent ? -c_tx->bytes_unsent & 0x3 : 0;
+
+ return c_tx->bytes_unsent + c_tx->ctrl_len + pad + MPA_CRC_SIZE;
+}
+
+
+/*
+ * siw_prepare_fpdu()
+ *
+ * Prepares transmit context to send out one FPDU if FPDU will contain
+ * user data and user data are not immediate data.
+ * Checks and locks involved memory segments of data to be sent.
+ * Computes maximum FPDU length to fill up TCP MSS if possible.
+ *
+ * @qp: QP from which to transmit
+ * @wqe: Current WQE causing transmission
+ *
+ * TODO: Take into account real available sendspace on socket
+ * to avoid header misalignment due to send pausing within
+ * fpdu transmission
+ */
+static int siw_prepare_fpdu(struct siw_qp *qp, struct siw_wqe *wqe)
+{
+ struct siw_iwarp_tx *c_tx = &qp->tx_ctx;
+ int rv = 0;
+
+ /*
+ * TODO: TCP Fragmentation dynamics needs for further investigation.
+ * Resuming SQ processing may start with full-sized packet
+ * or short packet which resets MSG_MORE and thus helps
+ * to synchronize.
+ * This version resumes with short packet.
+ */
+ c_tx->ctrl_len = iwarp_pktinfo[c_tx->pkt.ctrl.opcode].hdr_len;
+ c_tx->ctrl_sent = 0;
+
+ /*
+ * Update target buffer offset if any
+ */
+ if (!c_tx->pkt.ctrl.t) {
+ /* Untagged message */
+ c_tx->pkt.c_untagged.ddp_mo = cpu_to_be32(wqe->processed);
+ } else {
+ /* Tagged message */
+ if (wr_type(wqe) == SIW_WR_RDMA_READ_RESP) {
+ c_tx->pkt.c_tagged.ddp_to =
+ cpu_to_be64(wqe->wr.rresp.raddr + wqe->processed);
+ } else {
+ c_tx->pkt.c_tagged.ddp_to =
+ cpu_to_be64(wqe->wr.write.raddr + wqe->processed);
+ }
+ }
+
+ /* First guess: one big unsegmented DDP segment */
+ c_tx->bytes_unsent = wqe->bytes - wqe->processed;
+ c_tx->tcp_seglen -= siw_unseg_txlen(c_tx);
+
+ if (c_tx->tcp_seglen >= 0) {
+ /* Whole DDP segment fits into current TCP segment */
+ c_tx->pkt.ctrl.l = 1;
+ c_tx->pad = -c_tx->bytes_unsent & 0x3;
+ } else {
+ /* Trim DDP payload to fit into current TCP segment */
+ c_tx->bytes_unsent += c_tx->tcp_seglen;
+ c_tx->bytes_unsent &= ~0x3;
+ c_tx->pad = 0;
+ c_tx->pkt.ctrl.l = 0;
+ }
+ c_tx->pkt.ctrl.mpa_len =
+ htons(c_tx->ctrl_len + c_tx->bytes_unsent - MPA_HDR_SIZE);
+
+#ifdef SIW_TX_FULLSEGS
+ c_tx->fpdu_len =
+ c_tx->ctrl_len + c_tx->bytes_unsent + c_tx->pad + MPA_CRC_SIZE;
+#endif
+ /*
+ * Init MPA CRC computation
+ */
+ if (c_tx->crc_enabled) {
+ siw_crc_txhdr(c_tx);
+ c_tx->do_crc = 1;
+ }
+ if (c_tx->bytes_unsent && !SIW_INLINED_DATA(wqe)) {
+ struct siw_sge *sge = &wqe->wr.sgl.sge[c_tx->sge_idx];
+ /*
+ * Reference memory to be tx'd
+ */
+ BUG_ON(c_tx->sge_idx > wqe->wr.sgl.num_sge - 1);
+
+ if (wr_type(wqe) != SIW_WR_RDMA_READ_RESP)
+ rv = siw_check_sgl(qp->pd, sge, SR_MEM_LREAD,
+ c_tx->sge_off, c_tx->bytes_unsent);
+ else
+ rv = siw_check_sge(qp->pd, sge, SR_MEM_RREAD,
+ c_tx->sge_off, c_tx->bytes_unsent);
+ }
+ return rv;
+}
+
+#ifdef SIW_TX_FULLSEGS
+static inline int siw_test_wspace(struct socket *s, struct siw_iwarp_tx *c_tx)
+{
+ struct sock *sk = s->sk;
+ int rv = 0;
+
+ lock_sock(sk);
+ if (sk_stream_wspace(sk) < (int)c_tx->fpdu_len) {
+ set_bit(SOCK_NOSPACE, &s->flags);
+ rv = -EAGAIN;
+ }
+ release_sock(sk);
+
+ return rv;
+}
+#endif
+/*
+ * siw_qp_sq_proc_tx()
+ *
+ * Process one WQE which needs transmission on the wire.
+ * Return with:
+ * -EAGAIN, if handover to tcp remained incomplete
+ * 0, if handover to tcp complete
+ * < 0, if other errors happend.
+ *
+ * @qp: QP to send from
+ * @wqe: WQE causing transmission
+ */
+static int siw_qp_sq_proc_tx(struct siw_qp *qp, struct siw_wqe *wqe)
+{
+ struct siw_iwarp_tx *c_tx = &qp->tx_ctx;
+ struct socket *s = qp->attrs.llp_stream_handle;
+ int rv = 0;
+
+
+ if (wqe->wr_status == SR_WR_QUEUED) {
+ wqe->wr_status = SR_WR_INPROGRESS;
+
+ siw_calculate_tcpseg(c_tx, s);
+
+ rv = siw_qp_prepare_tx(c_tx);
+ if (rv == PKT_FRAGMENTED) {
+ c_tx->state = SIW_SEND_HDR;
+ rv = siw_prepare_fpdu(qp, wqe);
+ if (rv)
+ return rv;
+ } else if (rv == PKT_COMPLETE)
+ c_tx->state = SIW_SEND_SHORT_FPDU;
+ else
+ goto tx_done;
+ }
+next_segment:
+#ifdef SIW_TX_FULLSEGS
+ rv = siw_test_wspace(s, c_tx);
+ if (rv < 0)
+ goto tx_done;
+#endif
+
+ if (c_tx->state == SIW_SEND_SHORT_FPDU) {
+ enum siw_wr_opcode tx_type = wr_type(wqe);
+
+ /*
+ * Always end current TCP segment (no MSG_MORE flag):
+ * trying to fill segment would result in excessive delay.
+ */
+ rv = siw_tx_ctrl(c_tx, s, MSG_DONTWAIT);
+
+ if (!rv && tx_type != SIW_WR_RDMA_READ_REQ)
+ wqe->processed = wqe->bytes;
+
+ goto tx_done;
+
+ } else
+ rv = siw_tx_hdt(c_tx, s);
+
+ if (!rv) {
+ /* Verbs, 6.4.: Try stopping sending after a full DDP segment
+ * if the connection goes down (== peer halfclose)
+ */
+ if (unlikely(c_tx->tx_suspend)) {
+ rv = -ECONNABORTED;
+ goto tx_done;
+ }
+ /*
+ * One segment sent. Processing completed if last segment.
+ * Do next segment otherwise. Stop if tx error.
+ */
+ if (c_tx->pkt.ctrl.l == 1) {
+ dprint(DBG_TX, "(QP%d): WR completed\n", QP_ID(qp));
+ goto tx_done;
+ }
+ c_tx->state = SIW_SEND_HDR;
+
+ siw_calculate_tcpseg(c_tx, s);
+
+ rv = siw_prepare_fpdu(qp, wqe);
+ if (!rv)
+ goto next_segment;
+ }
+tx_done:
+ return rv;
+}
+
+
+/*
+ * siw_wqe_sq_processed()
+ *
+ * Called after WQE processing completed.
+ * If WQE is not of signalled typ, it can be released.
+ * If the ORQ is empty, a signalled WQE is attached to the CQ.
+ * Otherwise, it is appended to the end of the ORQ for later
+ * completion. To keep WQE ordering, the ORQ is always consumed FIFO.
+ */
+static void siw_wqe_sq_processed(struct siw_wqe *wqe, struct siw_qp *qp)
+{
+ unsigned long flags;
+ LIST_HEAD(c_list);
+
+ if (!(wr_flags(wqe) & IB_SEND_SIGNALED)) {
+ siw_wqe_put(wqe);
+ return;
+ }
+ lock_orq_rxsave(qp, flags);
+
+ if (ORQ_EMPTY(qp)) {
+ unlock_orq_rxsave(qp, flags);
+ dprint(DBG_WR|DBG_TX,
+ "(QP%d): Immediate completion, wr_type %d\n",
+ QP_ID(qp), wr_type(wqe));
+ list_add_tail(&wqe->list, &c_list);
+ siw_sq_complete(&c_list, qp, 1, wr_flags(wqe));
+ } else {
+ list_add_tail(&wqe->list, &qp->orq);
+ unlock_orq_rxsave(qp, flags);
+ dprint(DBG_WR|DBG_TX,
+ "(QP%d): Defer completion, wr_type %d\n",
+ QP_ID(qp), wr_type(wqe));
+ }
+}
+
+static int siw_qp_sq_proc_local(struct siw_qp *qp, struct siw_wqe *wqe)
+{
+ printk(KERN_ERR "local WR's not yet implemented\n");
+ BUG();
+ return 0;
+}
+
+
+/*
+ * siw_qp_sq_process()
+ *
+ * Core TX path routine for RDMAP/DDP/MPA using a TCP kernel socket.
+ * Sends RDMAP payload for the current SQ WR @wqe of @qp in one or more
+ * MPA FPDUs, each containing a DDP segment.
+ *
+ * SQ processing may occur in user context as a result of posting
+ * new WQE's or from siw_sq_work_handler() context. Processing in
+ * user context is limited to non-kernel verbs users.
+ *
+ * SQ processing may get paused anytime, possibly in the middle of a WR
+ * or FPDU, if insufficient send space is available. SQ processing
+ * gets resumed from siw_sq_work_handler(), if send space becomes
+ * available again.
+ *
+ * Must be called with the QP state read-locked.
+ *
+ * TODO:
+ * To be solved more seriously: an outbound RREQ can be satisfied
+ * by the corresponding RRESP _before_ it gets assigned to the ORQ.
+ * This happens regularly in RDMA READ via loopback case. Since both
+ * outbound RREQ and inbound RRESP can be handled by the same CPU
+ * locking the ORQ is dead-lock prone and thus not an option.
+ * Tentatively, the RREQ gets assigned to the ORQ _before_ being
+ * sent (and pulled back in case of send failure).
+ */
+int siw_qp_sq_process(struct siw_qp *qp, int user_ctx)
+{
+ struct siw_wqe *wqe;
+ enum siw_wr_opcode tx_type;
+ unsigned long flags;
+ int rv = 0;
+ int max_burst;
+
+ if (user_ctx)
+ max_burst = SQ_USER_MAXBURST;
+ else
+ max_burst = max(qp->attrs.sq_size, qp->attrs.ird);
+
+ atomic_inc(&qp->tx_ctx.in_use);
+
+ wait_event(qp->tx_ctx.waitq, atomic_read(&qp->tx_ctx.in_use) == 1);
+
+ wqe = tx_wqe(qp);
+ BUG_ON(wqe == NULL);
+
+next_wqe:
+ /*
+ * Stop QP processing if SQ state changed
+ */
+ if (unlikely(qp->tx_ctx.tx_suspend)) {
+ dprint(DBG_WR|DBG_TX, "(QP%d): tx suspend\n", QP_ID(qp));
+ goto done;
+ }
+ tx_type = wr_type(wqe);
+
+ dprint(DBG_WR|DBG_TX,
+ " QP(%d): WR type %d, state %d, data %u, sent %u, id %llu\n",
+ QP_ID(qp), wr_type(wqe), wqe->wr_status, wqe->bytes,
+ wqe->processed, (unsigned long long)wr_id(wqe));
+
+ if (SIW_WQE_IS_TX(wqe))
+ rv = siw_qp_sq_proc_tx(qp, wqe);
+ else
+ rv = siw_qp_sq_proc_local(qp, wqe);
+
+ if (!rv) {
+ /*
+ * WQE processing done
+ */
+ switch (tx_type) {
+
+ case SIW_WR_SEND:
+ case SIW_WR_RDMA_WRITE:
+
+ wqe->wc_status = IB_WC_SUCCESS;
+ wqe->wr_status = SR_WR_DONE;
+ siw_wqe_sq_processed(wqe, qp);
+ break;
+
+ case SIW_WR_RDMA_READ_REQ:
+ /*
+ * already enqueued to ORQ queue
+ */
+ break;
+
+ case SIW_WR_RDMA_READ_RESP:
+ /*
+ * silently recyclye wqe
+ */
+ /* XXX DEBUG AID, please remove */
+ wqe->wr_status = SR_WR_DONE;
+ siw_wqe_put(wqe);
+ break;
+ default:
+ BUG();
+ }
+
+ lock_sq_rxsave(qp, flags);
+
+ wqe = siw_next_tx_wqe(qp);
+ if (!wqe) {
+ tx_wqe(qp) = NULL;
+ unlock_sq_rxsave(qp, flags);
+ goto done;
+ }
+ if (wr_type(wqe) == SIW_WR_RDMA_READ_REQ) {
+ if (ORD_SUSPEND_SQ(qp)) {
+ tx_wqe(qp) = NULL;
+ unlock_sq_rxsave(qp, flags);
+ dprint(DBG_WR|DBG_TX,
+ " QP%d PAUSE SQ: ORD limit\n",
+ QP_ID(qp));
+ goto done;
+ } else {
+ tx_wqe(qp) = wqe;
+ siw_rreq_queue(wqe, qp);
+ }
+ } else {
+ list_del_init(&wqe->list);
+ tx_wqe(qp) = wqe;
+ }
+ unlock_sq_rxsave(qp, flags);
+
+ if (--max_burst == 0) {
+ if (user_ctx) {
+ /*
+ * Avoid to keep the user sending from its
+ * context for too long (blocking user thread)
+ */
+ siw_sq_queue_work(qp);
+ goto done;
+ } else {
+ /*
+ * Avoid to starve other QP's tx if consumer
+ * keeps posting new tx work for current cpu.
+ */
+ int workq_len =
+ atomic_read(&get_cpu_var(siw_workq_len));
+
+ put_cpu_var(siw_workq_len);
+
+ if (workq_len) {
+ /* Another QP's work on same WQ */
+ siw_sq_queue_work(qp);
+ goto done;
+ }
+ }
+ max_burst = max(qp->attrs.sq_size, qp->attrs.ird);
+ }
+ goto next_wqe;
+
+ } else if (rv == -EAGAIN) {
+ dprint(DBG_WR|DBG_TX,
+ "(QP%d): SQ paused: hd/tr %d of %d, data %d\n",
+ QP_ID(qp), qp->tx_ctx.ctrl_sent, qp->tx_ctx.ctrl_len,
+ qp->tx_ctx.bytes_unsent);
+ rv = 0;
+ goto done;
+ } else {
+ /*
+ * WQE processing failed.
+ * Verbs 8.3.2:
+ * o It turns any WQE into a signalled WQE.
+ * o Local catastrophic error must be surfaced
+ * o QP must be moved into Terminate state: done by code
+ * doing socket state change processing
+ *
+ * o TODO: Termination message must be sent.
+ * o TODO: Implement more precise work completion errors,
+ * see enum ib_wc_status in ib_verbs.h
+ */
+ dprint(DBG_ON, " (QP%d): WQE type %d processing failed: %d\n",
+ QP_ID(qp), wr_type(wqe), rv);
+
+ lock_sq_rxsave(qp, flags);
+ /*
+ * RREQ may have already been completed by inbound RRESP!
+ */
+ if (tx_type == RDMAP_RDMA_READ_REQ) {
+ lock_orq(qp);
+ if (!ORQ_EMPTY(qp) &&
+ wqe == list_entry_wqe(qp->orq.prev)) {
+ /*
+ * wqe still on the ORQ
+ * TODO: fix a potential race condition if the
+ * rx path is currently referencing the wqe(!)
+ */
+ dprint(DBG_ON, " (QP%d): Bad RREQ in ORQ\n",
+ QP_ID(qp));
+ list_del_init(&wqe->list);
+ unlock_orq(qp);
+ } else {
+ /*
+ * already completed by inbound RRESP
+ */
+ dprint(DBG_ON, " (QP%d): Bad RREQ completed\n",
+ QP_ID(qp));
+ unlock_orq(qp);
+ tx_wqe(qp) = NULL;
+ unlock_sq_rxsave(qp, flags);
+
+ goto done;
+ }
+ }
+ tx_wqe(qp) = NULL;
+ unlock_sq_rxsave(qp, flags);
+ /*
+ * immediately suspends further TX processing
+ */
+ if (!qp->tx_ctx.tx_suspend)
+ siw_qp_cm_drop(qp, 0);
+
+ switch (tx_type) {
+
+ case SIW_WR_SEND:
+ case SIW_WR_RDMA_WRITE:
+ case SIW_WR_RDMA_READ_REQ:
+ wqe->wr_status = SR_WR_DONE;
+ wqe->wc_status = IB_WC_LOC_QP_OP_ERR;
+ wqe->error = rv;
+ wr_flags(wqe) |= IB_SEND_SIGNALED;
+ if (tx_type != SIW_WR_RDMA_READ_REQ)
+ /*
+ * RREQ already enqueued to ORQ queue
+ */
+ siw_wqe_sq_processed(wqe, qp);
+
+ siw_async_ev(qp, NULL, IB_EVENT_QP_FATAL);
+
+ break;
+
+ case SIW_WR_RDMA_READ_RESP:
+ /*
+ * Recyclye wqe
+ */
+ dprint(DBG_WR|DBG_TX|DBG_ON, "(QP%d): "
+ "Processing RRESPONSE failed with %d\n",
+ QP_ID(qp), rv);
+
+ siw_async_ev(qp, NULL, IB_EVENT_QP_REQ_ERR);
+
+ siw_wqe_put(wqe);
+ break;
+
+ default:
+ BUG();
+ }
+ }
+done:
+ atomic_dec(&qp->tx_ctx.in_use);
+ wake_up(&qp->tx_ctx.waitq);
+
+ return rv;
+}
+
+static struct workqueue_struct *siw_sq_wq;
+
+int __init siw_sq_worker_init(void)
+{
+ siw_sq_wq = create_workqueue("siw_sq_wq");
+ if (!siw_sq_wq)
+ return -ENOMEM;
+
+ dprint(DBG_TX|DBG_OBJ, " Init WQ\n");
+ return 0;
+}
+
+
+void __exit siw_sq_worker_exit(void)
+{
+ dprint(DBG_TX|DBG_OBJ, " Destroy WQ\n");
+ if (siw_sq_wq) {
+ flush_workqueue(siw_sq_wq);
+ destroy_workqueue(siw_sq_wq);
+ }
+}
+
+
+/*
+ * siw_sq_work_handler()
+ *
+ * Scheduled by siw_qp_llp_write_space() socket callback if socket
+ * send space became available again. This function resumes SQ
+ * processing.
+ */
+static void siw_sq_work_handler(struct work_struct *w)
+{
+ struct siw_sq_work *this_work;
+ struct siw_qp *qp;
+ int rv;
+
+ atomic_dec(&get_cpu_var(siw_workq_len));
+ put_cpu_var(siw_workq_len);
+
+ this_work = container_of(w, struct siw_sq_work, work);
+ qp = container_of(this_work, struct siw_qp, sq_work);
+
+ dprint(DBG_TX|DBG_OBJ, "(QP%d)\n", QP_ID(qp));
+
+ if (down_read_trylock(&qp->state_lock)) {
+ if (likely(qp->attrs.state == SIW_QP_STATE_RTS &&
+ !qp->tx_ctx.tx_suspend)) {
+
+ rv = siw_qp_sq_process(qp, 0);
+ up_read(&qp->state_lock);
+
+ if (rv < 0) {
+ dprint(DBG_TX, "(QP%d): failed: %d\n",
+ QP_ID(qp), rv);
+
+ if (!qp->tx_ctx.tx_suspend)
+ siw_qp_cm_drop(qp, 0);
+ }
+ } else {
+ dprint(DBG_ON|DBG_TX, "(QP%d): state: %d %d\n",
+ QP_ID(qp), qp->attrs.state,
+ qp->tx_ctx.tx_suspend);
+ up_read(&qp->state_lock);
+ }
+ } else {
+ dprint(DBG_ON|DBG_TX, "(QP%d): QP locked\n", QP_ID(qp));
+ }
+ siw_qp_put(qp);
+}
+
+
+int siw_sq_queue_work(struct siw_qp *qp)
+{
+ int cpu, rv;
+
+ dprint(DBG_TX|DBG_OBJ, "(QP%d)\n", QP_ID(qp));
+
+ siw_qp_get(qp);
+
+ INIT_WORK(&qp->sq_work.work, siw_sq_work_handler);
+
+ cpu = get_cpu();
+#if NR_CPUS > 1
+ if (in_softirq()) {
+ int sq_cpu;
+ if (cpu == qp->cpu) {
+ /*
+ * Try not to use the current CPU for tx traffic.
+ */
+ for_each_online_cpu(sq_cpu) {
+ if (sq_cpu != cpu)
+ break;
+ }
+ } else
+ sq_cpu = qp->cpu;
+
+ if (cpu_online(sq_cpu))
+ cpu = sq_cpu;
+ }
+#endif
+ atomic_inc(&per_cpu(siw_workq_len, cpu));
+ /*
+ * Remember CPU: Avoid spreading SQ work of QP over WQ's
+ */
+ qp->cpu = cpu;
+ rv = queue_work_on(cpu, siw_sq_wq, &qp->sq_work.work);
+
+ put_cpu();
+
+ return rv;
+}
--
1.5.4.3
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