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OpenCloudOS-Kernel/net/sunrpc/xprtrdma/verbs.c

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/*
* Copyright (c) 2014-2017 Oracle. All rights reserved.
* Copyright (c) 2003-2007 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.
*/
/*
* verbs.c
*
* Encapsulates the major functions managing:
* o adapters
* o endpoints
* o connections
* o buffer memory
*/
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/svc_rdma.h>
#include <asm-generic/barrier.h>
#include <asm/bitops.h>
#include <rdma/ib_cm.h>
#include "xprt_rdma.h"
/*
* Globals/Macros
*/
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
/*
* internal functions
*/
static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
int
rpcrdma_alloc_wq(void)
{
struct workqueue_struct *recv_wq;
recv_wq = alloc_workqueue("xprtrdma_receive",
WQ_MEM_RECLAIM | WQ_HIGHPRI,
0);
if (!recv_wq)
return -ENOMEM;
rpcrdma_receive_wq = recv_wq;
return 0;
}
void
rpcrdma_destroy_wq(void)
{
struct workqueue_struct *wq;
if (rpcrdma_receive_wq) {
wq = rpcrdma_receive_wq;
rpcrdma_receive_wq = NULL;
destroy_workqueue(wq);
}
}
static void
rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
{
struct rpcrdma_ep *ep = context;
struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
rx_ep);
trace_xprtrdma_qp_error(r_xprt, event);
pr_err("rpcrdma: %s on device %s ep %p\n",
ib_event_msg(event->event), event->device->name, context);
if (ep->rep_connected == 1) {
ep->rep_connected = -EIO;
rpcrdma_conn_func(ep);
wake_up_all(&ep->rep_connect_wait);
}
}
/**
* rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
{
struct ib_cqe *cqe = wc->wr_cqe;
struct rpcrdma_sendctx *sc =
container_of(cqe, struct rpcrdma_sendctx, sc_cqe);
/* WARNING: Only wr_cqe and status are reliable at this point */
trace_xprtrdma_wc_send(sc, wc);
if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
ib_wc_status_msg(wc->status),
wc->status, wc->vendor_err);
rpcrdma_sendctx_put_locked(sc);
}
/**
* rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
{
struct ib_cqe *cqe = wc->wr_cqe;
struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
rr_cqe);
/* WARNING: Only wr_id and status are reliable at this point */
trace_xprtrdma_wc_receive(rep, wc);
if (wc->status != IB_WC_SUCCESS)
goto out_fail;
/* status == SUCCESS means all fields in wc are trustworthy */
rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
rep->rr_wc_flags = wc->wc_flags;
rep->rr_inv_rkey = wc->ex.invalidate_rkey;
ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
rdmab_addr(rep->rr_rdmabuf),
wc->byte_len, DMA_FROM_DEVICE);
out_schedule:
rpcrdma_reply_handler(rep);
return;
out_fail:
if (wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
ib_wc_status_msg(wc->status),
wc->status, wc->vendor_err);
rpcrdma_set_xdrlen(&rep->rr_hdrbuf, 0);
goto out_schedule;
}
static void
rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
struct rdma_conn_param *param)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
const struct rpcrdma_connect_private *pmsg = param->private_data;
unsigned int rsize, wsize;
/* Default settings for RPC-over-RDMA Version One */
r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
if (pmsg &&
pmsg->cp_magic == rpcrdma_cmp_magic &&
pmsg->cp_version == RPCRDMA_CMP_VERSION) {
r_xprt->rx_ia.ri_implicit_roundup = true;
rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
}
if (rsize < cdata->inline_rsize)
cdata->inline_rsize = rsize;
if (wsize < cdata->inline_wsize)
cdata->inline_wsize = wsize;
dprintk("RPC: %s: max send %u, max recv %u\n",
__func__, cdata->inline_wsize, cdata->inline_rsize);
rpcrdma_set_max_header_sizes(r_xprt);
}
static int
rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
{
struct rpcrdma_xprt *xprt = id->context;
struct rpcrdma_ia *ia = &xprt->rx_ia;
struct rpcrdma_ep *ep = &xprt->rx_ep;
int connstate = 0;
trace_xprtrdma_conn_upcall(xprt, event);
switch (event->event) {
case RDMA_CM_EVENT_ADDR_RESOLVED:
case RDMA_CM_EVENT_ROUTE_RESOLVED:
ia->ri_async_rc = 0;
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ADDR_ERROR:
ia->ri_async_rc = -EHOSTUNREACH;
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ROUTE_ERROR:
ia->ri_async_rc = -ENETUNREACH;
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_DEVICE_REMOVAL:
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
pr_info("rpcrdma: removing device %s for %s:%s\n",
ia->ri_device->name,
rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt));
#endif
set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
ep->rep_connected = -ENODEV;
xprt_force_disconnect(&xprt->rx_xprt);
wait_for_completion(&ia->ri_remove_done);
ia->ri_id = NULL;
ia->ri_device = NULL;
/* Return 1 to ensure the core destroys the id. */
return 1;
case RDMA_CM_EVENT_ESTABLISHED:
++xprt->rx_xprt.connect_cookie;
connstate = 1;
rpcrdma_update_connect_private(xprt, &event->param.conn);
goto connected;
case RDMA_CM_EVENT_CONNECT_ERROR:
connstate = -ENOTCONN;
goto connected;
case RDMA_CM_EVENT_UNREACHABLE:
connstate = -ENETDOWN;
goto connected;
case RDMA_CM_EVENT_REJECTED:
dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
rdma_reject_msg(id, event->status));
connstate = -ECONNREFUSED;
if (event->status == IB_CM_REJ_STALE_CONN)
connstate = -EAGAIN;
goto connected;
case RDMA_CM_EVENT_DISCONNECTED:
++xprt->rx_xprt.connect_cookie;
connstate = -ECONNABORTED;
connected:
xprt->rx_buf.rb_credits = 1;
ep->rep_connected = connstate;
rpcrdma_conn_func(ep);
wake_up_all(&ep->rep_connect_wait);
/*FALLTHROUGH*/
default:
dprintk("RPC: %s: %s:%s on %s/%s (ep 0x%p): %s\n",
__func__,
rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
ia->ri_device->name, ia->ri_ops->ro_displayname,
ep, rdma_event_msg(event->event));
break;
}
return 0;
}
static struct rdma_cm_id *
rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
{
unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
struct rdma_cm_id *id;
int rc;
trace_xprtrdma_conn_start(xprt);
init_completion(&ia->ri_done);
init_completion(&ia->ri_remove_done);
id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
IB_QPT_RC);
if (IS_ERR(id)) {
rc = PTR_ERR(id);
dprintk("RPC: %s: rdma_create_id() failed %i\n",
__func__, rc);
return id;
}
ia->ri_async_rc = -ETIMEDOUT;
rc = rdma_resolve_addr(id, NULL,
(struct sockaddr *)&xprt->rx_xprt.addr,
RDMA_RESOLVE_TIMEOUT);
if (rc) {
dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
__func__, rc);
goto out;
}
rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
if (rc < 0) {
trace_xprtrdma_conn_tout(xprt);
goto out;
}
rc = ia->ri_async_rc;
if (rc)
goto out;
ia->ri_async_rc = -ETIMEDOUT;
rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
if (rc) {
dprintk("RPC: %s: rdma_resolve_route() failed %i\n",
__func__, rc);
goto out;
}
rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
if (rc < 0) {
trace_xprtrdma_conn_tout(xprt);
goto out;
}
rc = ia->ri_async_rc;
if (rc)
goto out;
return id;
out:
rdma_destroy_id(id);
return ERR_PTR(rc);
}
/*
* Exported functions.
*/
/**
* rpcrdma_ia_open - Open and initialize an Interface Adapter.
* @xprt: transport with IA to (re)initialize
*
* Returns 0 on success, negative errno if an appropriate
* Interface Adapter could not be found and opened.
*/
int
rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
{
struct rpcrdma_ia *ia = &xprt->rx_ia;
int rc;
ia->ri_id = rpcrdma_create_id(xprt, ia);
if (IS_ERR(ia->ri_id)) {
rc = PTR_ERR(ia->ri_id);
goto out_err;
}
ia->ri_device = ia->ri_id->device;
ia->ri_pd = ib_alloc_pd(ia->ri_device, 0);
if (IS_ERR(ia->ri_pd)) {
rc = PTR_ERR(ia->ri_pd);
pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
goto out_err;
}
switch (xprt_rdma_memreg_strategy) {
case RPCRDMA_FRWR:
if (frwr_is_supported(ia)) {
ia->ri_ops = &rpcrdma_frwr_memreg_ops;
break;
}
/*FALLTHROUGH*/
case RPCRDMA_MTHCAFMR:
if (fmr_is_supported(ia)) {
ia->ri_ops = &rpcrdma_fmr_memreg_ops;
break;
}
/*FALLTHROUGH*/
default:
pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
ia->ri_device->name, xprt_rdma_memreg_strategy);
rc = -EINVAL;
goto out_err;
}
return 0;
out_err:
rpcrdma_ia_close(ia);
return rc;
}
/**
* rpcrdma_ia_remove - Handle device driver unload
* @ia: interface adapter being removed
*
* Divest transport H/W resources associated with this adapter,
* but allow it to be restored later.
*/
void
rpcrdma_ia_remove(struct rpcrdma_ia *ia)
{
struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
rx_ia);
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_req *req;
struct rpcrdma_rep *rep;
cancel_delayed_work_sync(&buf->rb_refresh_worker);
/* This is similar to rpcrdma_ep_destroy, but:
* - Don't cancel the connect worker.
* - Don't call rpcrdma_ep_disconnect, which waits
* for another conn upcall, which will deadlock.
* - rdma_disconnect is unneeded, the underlying
* connection is already gone.
*/
if (ia->ri_id->qp) {
ib_drain_qp(ia->ri_id->qp);
rdma_destroy_qp(ia->ri_id);
ia->ri_id->qp = NULL;
}
ib_free_cq(ep->rep_attr.recv_cq);
ep->rep_attr.recv_cq = NULL;
ib_free_cq(ep->rep_attr.send_cq);
ep->rep_attr.send_cq = NULL;
/* The ULP is responsible for ensuring all DMA
* mappings and MRs are gone.
*/
list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
}
rpcrdma_mrs_destroy(buf);
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
/* Allow waiters to continue */
complete(&ia->ri_remove_done);
trace_xprtrdma_remove(r_xprt);
}
/**
* rpcrdma_ia_close - Clean up/close an IA.
* @ia: interface adapter to close
*
*/
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
if (ia->ri_id->qp)
rdma_destroy_qp(ia->ri_id);
rdma_destroy_id(ia->ri_id);
}
ia->ri_id = NULL;
ia->ri_device = NULL;
/* If the pd is still busy, xprtrdma missed freeing a resource */
if (ia->ri_pd && !IS_ERR(ia->ri_pd))
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
}
/*
* Create unconnected endpoint.
*/
int
rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
struct rpcrdma_create_data_internal *cdata)
{
struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
unsigned int max_qp_wr, max_sge;
struct ib_cq *sendcq, *recvcq;
int rc;
max_sge = min_t(unsigned int, ia->ri_device->attrs.max_sge,
RPCRDMA_MAX_SEND_SGES);
if (max_sge < RPCRDMA_MIN_SEND_SGES) {
pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
return -ENOMEM;
}
ia->ri_max_send_sges = max_sge;
if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
dprintk("RPC: %s: insufficient wqe's available\n",
__func__);
return -ENOMEM;
}
max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS - 1;
/* check provider's send/recv wr limits */
if (cdata->max_requests > max_qp_wr)
cdata->max_requests = max_qp_wr;
ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
ep->rep_attr.qp_context = ep;
ep->rep_attr.srq = NULL;
ep->rep_attr.cap.max_send_wr = cdata->max_requests;
ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
ep->rep_attr.cap.max_send_wr += 1; /* drain cqe */
rc = ia->ri_ops->ro_open(ia, ep, cdata);
if (rc)
return rc;
ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
ep->rep_attr.cap.max_recv_wr += 1; /* drain cqe */
ep->rep_attr.cap.max_send_sge = max_sge;
ep->rep_attr.cap.max_recv_sge = 1;
ep->rep_attr.cap.max_inline_data = 0;
ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
ep->rep_attr.qp_type = IB_QPT_RC;
ep->rep_attr.port_num = ~0;
dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
"iovs: send %d recv %d\n",
__func__,
ep->rep_attr.cap.max_send_wr,
ep->rep_attr.cap.max_recv_wr,
ep->rep_attr.cap.max_send_sge,
ep->rep_attr.cap.max_recv_sge);
/* set trigger for requesting send completion */
ep->rep_send_batch = min_t(unsigned int, RPCRDMA_MAX_SEND_BATCH,
cdata->max_requests >> 2);
ep->rep_send_count = ep->rep_send_batch;
init_waitqueue_head(&ep->rep_connect_wait);
INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
sendcq = ib_alloc_cq(ia->ri_device, NULL,
ep->rep_attr.cap.max_send_wr + 1,
1, IB_POLL_WORKQUEUE);
if (IS_ERR(sendcq)) {
rc = PTR_ERR(sendcq);
dprintk("RPC: %s: failed to create send CQ: %i\n",
__func__, rc);
goto out1;
}
recvcq = ib_alloc_cq(ia->ri_device, NULL,
ep->rep_attr.cap.max_recv_wr + 1,
0, IB_POLL_WORKQUEUE);
if (IS_ERR(recvcq)) {
rc = PTR_ERR(recvcq);
dprintk("RPC: %s: failed to create recv CQ: %i\n",
__func__, rc);
goto out2;
}
ep->rep_attr.send_cq = sendcq;
ep->rep_attr.recv_cq = recvcq;
/* Initialize cma parameters */
memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
/* Prepare RDMA-CM private message */
pmsg->cp_magic = rpcrdma_cmp_magic;
pmsg->cp_version = RPCRDMA_CMP_VERSION;
pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);
pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);
ep->rep_remote_cma.private_data = pmsg;
ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
/* Client offers RDMA Read but does not initiate */
ep->rep_remote_cma.initiator_depth = 0;
ep->rep_remote_cma.responder_resources =
min_t(int, U8_MAX, ia->ri_device->attrs.max_qp_rd_atom);
/* Limit transport retries so client can detect server
* GID changes quickly. RPC layer handles re-establishing
* transport connection and retransmission.
*/
ep->rep_remote_cma.retry_count = 6;
/* RPC-over-RDMA handles its own flow control. In addition,
* make all RNR NAKs visible so we know that RPC-over-RDMA
* flow control is working correctly (no NAKs should be seen).
*/
ep->rep_remote_cma.flow_control = 0;
ep->rep_remote_cma.rnr_retry_count = 0;
return 0;
out2:
ib_free_cq(sendcq);
out1:
return rc;
}
/*
* rpcrdma_ep_destroy
*
* Disconnect and destroy endpoint. After this, the only
* valid operations on the ep are to free it (if dynamically
* allocated) or re-create it.
*/
void
rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
cancel_delayed_work_sync(&ep->rep_connect_worker);
if (ia->ri_id && ia->ri_id->qp) {
rpcrdma_ep_disconnect(ep, ia);
rdma_destroy_qp(ia->ri_id);
ia->ri_id->qp = NULL;
}
if (ep->rep_attr.recv_cq)
ib_free_cq(ep->rep_attr.recv_cq);
if (ep->rep_attr.send_cq)
ib_free_cq(ep->rep_attr.send_cq);
}
/* Re-establish a connection after a device removal event.
* Unlike a normal reconnection, a fresh PD and a new set
* of MRs and buffers is needed.
*/
static int
rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
int rc, err;
trace_xprtrdma_reinsert(r_xprt);
rc = -EHOSTUNREACH;
if (rpcrdma_ia_open(r_xprt))
goto out1;
rc = -ENOMEM;
err = rpcrdma_ep_create(ep, ia, &r_xprt->rx_data);
if (err) {
pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
goto out2;
}
rc = -ENETUNREACH;
err = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
if (err) {
pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
goto out3;
}
rpcrdma_mrs_create(r_xprt);
return 0;
out3:
rpcrdma_ep_destroy(ep, ia);
out2:
rpcrdma_ia_close(ia);
out1:
return rc;
}
static int
rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
struct rpcrdma_ia *ia)
{
struct rdma_cm_id *id, *old;
int err, rc;
trace_xprtrdma_reconnect(r_xprt);
rpcrdma_ep_disconnect(ep, ia);
rc = -EHOSTUNREACH;
id = rpcrdma_create_id(r_xprt, ia);
if (IS_ERR(id))
goto out;
/* As long as the new ID points to the same device as the
* old ID, we can reuse the transport's existing PD and all
* previously allocated MRs. Also, the same device means
* the transport's previous DMA mappings are still valid.
*
* This is a sanity check only. There should be no way these
* point to two different devices here.
*/
old = id;
rc = -ENETUNREACH;
if (ia->ri_device != id->device) {
pr_err("rpcrdma: can't reconnect on different device!\n");
goto out_destroy;
}
err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
if (err) {
dprintk("RPC: %s: rdma_create_qp returned %d\n",
__func__, err);
goto out_destroy;
}
/* Atomically replace the transport's ID and QP. */
rc = 0;
old = ia->ri_id;
ia->ri_id = id;
rdma_destroy_qp(old);
out_destroy:
rdma_destroy_id(old);
out:
return rc;
}
/*
* Connect unconnected endpoint.
*/
int
rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
rx_ia);
unsigned int extras;
int rc;
retry:
switch (ep->rep_connected) {
case 0:
dprintk("RPC: %s: connecting...\n", __func__);
rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
if (rc) {
dprintk("RPC: %s: rdma_create_qp failed %i\n",
__func__, rc);
rc = -ENETUNREACH;
goto out_noupdate;
}
break;
case -ENODEV:
rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
if (rc)
goto out_noupdate;
break;
default:
rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
if (rc)
goto out;
}
ep->rep_connected = 0;
rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
if (rc) {
dprintk("RPC: %s: rdma_connect() failed with %i\n",
__func__, rc);
goto out;
}
wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
if (ep->rep_connected <= 0) {
if (ep->rep_connected == -EAGAIN)
goto retry;
rc = ep->rep_connected;
goto out;
}
dprintk("RPC: %s: connected\n", __func__);
extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
if (extras)
rpcrdma_ep_post_extra_recv(r_xprt, extras);
out:
if (rc)
ep->rep_connected = rc;
out_noupdate:
return rc;
}
/*
* rpcrdma_ep_disconnect
*
* This is separate from destroy to facilitate the ability
* to reconnect without recreating the endpoint.
*
* This call is not reentrant, and must not be made in parallel
* on the same endpoint.
*/
void
rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
int rc;
rc = rdma_disconnect(ia->ri_id);
if (!rc)
/* returns without wait if not connected */
wait_event_interruptible(ep->rep_connect_wait,
ep->rep_connected != 1);
else
ep->rep_connected = rc;
trace_xprtrdma_disconnect(container_of(ep, struct rpcrdma_xprt,
rx_ep), rc);
ib_drain_qp(ia->ri_id->qp);
}
/* Fixed-size circular FIFO queue. This implementation is wait-free and
* lock-free.
*
* Consumer is the code path that posts Sends. This path dequeues a
* sendctx for use by a Send operation. Multiple consumer threads
* are serialized by the RPC transport lock, which allows only one
* ->send_request call at a time.
*
* Producer is the code path that handles Send completions. This path
* enqueues a sendctx that has been completed. Multiple producer
* threads are serialized by the ib_poll_cq() function.
*/
/* rpcrdma_sendctxs_destroy() assumes caller has already quiesced
* queue activity, and ib_drain_qp has flushed all remaining Send
* requests.
*/
static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
{
unsigned long i;
for (i = 0; i <= buf->rb_sc_last; i++)
kfree(buf->rb_sc_ctxs[i]);
kfree(buf->rb_sc_ctxs);
}
static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
{
struct rpcrdma_sendctx *sc;
sc = kzalloc(sizeof(*sc) +
ia->ri_max_send_sges * sizeof(struct ib_sge),
GFP_KERNEL);
if (!sc)
return NULL;
sc->sc_wr.wr_cqe = &sc->sc_cqe;
sc->sc_wr.sg_list = sc->sc_sges;
sc->sc_wr.opcode = IB_WR_SEND;
sc->sc_cqe.done = rpcrdma_wc_send;
return sc;
}
static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_sendctx *sc;
unsigned long i;
/* Maximum number of concurrent outstanding Send WRs. Capping
* the circular queue size stops Send Queue overflow by causing
* the ->send_request call to fail temporarily before too many
* Sends are posted.
*/
i = buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS;
dprintk("RPC: %s: allocating %lu send_ctxs\n", __func__, i);
buf->rb_sc_ctxs = kcalloc(i, sizeof(sc), GFP_KERNEL);
if (!buf->rb_sc_ctxs)
return -ENOMEM;
buf->rb_sc_last = i - 1;
for (i = 0; i <= buf->rb_sc_last; i++) {
sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
if (!sc)
goto out_destroy;
sc->sc_xprt = r_xprt;
buf->rb_sc_ctxs[i] = sc;
}
return 0;
out_destroy:
rpcrdma_sendctxs_destroy(buf);
return -ENOMEM;
}
/* The sendctx queue is not guaranteed to have a size that is a
* power of two, thus the helpers in circ_buf.h cannot be used.
* The other option is to use modulus (%), which can be expensive.
*/
static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf,
unsigned long item)
{
return likely(item < buf->rb_sc_last) ? item + 1 : 0;
}
/**
* rpcrdma_sendctx_get_locked - Acquire a send context
* @buf: transport buffers from which to acquire an unused context
*
* Returns pointer to a free send completion context; or NULL if
* the queue is empty.
*
* Usage: Called to acquire an SGE array before preparing a Send WR.
*
* The caller serializes calls to this function (per rpcrdma_buffer),
* and provides an effective memory barrier that flushes the new value
* of rb_sc_head.
*/
struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_buffer *buf)
{
struct rpcrdma_xprt *r_xprt;
struct rpcrdma_sendctx *sc;
unsigned long next_head;
next_head = rpcrdma_sendctx_next(buf, buf->rb_sc_head);
if (next_head == READ_ONCE(buf->rb_sc_tail))
goto out_emptyq;
/* ORDER: item must be accessed _before_ head is updated */
sc = buf->rb_sc_ctxs[next_head];
/* Releasing the lock in the caller acts as a memory
* barrier that flushes rb_sc_head.
*/
buf->rb_sc_head = next_head;
return sc;
out_emptyq:
/* The queue is "empty" if there have not been enough Send
* completions recently. This is a sign the Send Queue is
* backing up. Cause the caller to pause and try again.
*/
dprintk("RPC: %s: empty sendctx queue\n", __func__);
r_xprt = container_of(buf, struct rpcrdma_xprt, rx_buf);
r_xprt->rx_stats.empty_sendctx_q++;
return NULL;
}
/**
* rpcrdma_sendctx_put_locked - Release a send context
* @sc: send context to release
*
* Usage: Called from Send completion to return a sendctxt
* to the queue.
*
* The caller serializes calls to this function (per rpcrdma_buffer).
*/
void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
{
struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
unsigned long next_tail;
/* Unmap SGEs of previously completed by unsignaled
* Sends by walking up the queue until @sc is found.
*/
next_tail = buf->rb_sc_tail;
do {
next_tail = rpcrdma_sendctx_next(buf, next_tail);
/* ORDER: item must be accessed _before_ tail is updated */
rpcrdma_unmap_sendctx(buf->rb_sc_ctxs[next_tail]);
} while (buf->rb_sc_ctxs[next_tail] != sc);
/* Paired with READ_ONCE */
smp_store_release(&buf->rb_sc_tail, next_tail);
}
static void
rpcrdma_mr_recovery_worker(struct work_struct *work)
{
struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
rb_recovery_worker.work);
struct rpcrdma_mr *mr;
spin_lock(&buf->rb_recovery_lock);
while (!list_empty(&buf->rb_stale_mrs)) {
mr = rpcrdma_mr_pop(&buf->rb_stale_mrs);
spin_unlock(&buf->rb_recovery_lock);
trace_xprtrdma_recover_mr(mr);
mr->mr_xprt->rx_ia.ri_ops->ro_recover_mr(mr);
spin_lock(&buf->rb_recovery_lock);
}
spin_unlock(&buf->rb_recovery_lock);
}
void
rpcrdma_mr_defer_recovery(struct rpcrdma_mr *mr)
{
struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
spin_lock(&buf->rb_recovery_lock);
rpcrdma_mr_push(mr, &buf->rb_stale_mrs);
spin_unlock(&buf->rb_recovery_lock);
schedule_delayed_work(&buf->rb_recovery_worker, 0);
}
static void
rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
unsigned int count;
LIST_HEAD(free);
LIST_HEAD(all);
for (count = 0; count < 3; count++) {
struct rpcrdma_mr *mr;
int rc;
mr = kzalloc(sizeof(*mr), GFP_KERNEL);
if (!mr)
break;
rc = ia->ri_ops->ro_init_mr(ia, mr);
if (rc) {
kfree(mr);
break;
}
mr->mr_xprt = r_xprt;
list_add(&mr->mr_list, &free);
list_add(&mr->mr_all, &all);
}
spin_lock(&buf->rb_mrlock);
list_splice(&free, &buf->rb_mrs);
list_splice(&all, &buf->rb_all);
r_xprt->rx_stats.mrs_allocated += count;
spin_unlock(&buf->rb_mrlock);
trace_xprtrdma_createmrs(r_xprt, count);
xprt_write_space(&r_xprt->rx_xprt);
}
static void
rpcrdma_mr_refresh_worker(struct work_struct *work)
{
struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
rb_refresh_worker.work);
struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
rx_buf);
rpcrdma_mrs_create(r_xprt);
}
struct rpcrdma_req *
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
struct rpcrdma_regbuf *rb;
struct rpcrdma_req *req;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (req == NULL)
return ERR_PTR(-ENOMEM);
rb = rpcrdma_alloc_regbuf(RPCRDMA_HDRBUF_SIZE,
DMA_TO_DEVICE, GFP_KERNEL);
if (IS_ERR(rb)) {
kfree(req);
return ERR_PTR(-ENOMEM);
}
req->rl_rdmabuf = rb;
xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
req->rl_buffer = buffer;
INIT_LIST_HEAD(&req->rl_registered);
spin_lock(&buffer->rb_reqslock);
list_add(&req->rl_all, &buffer->rb_allreqs);
spin_unlock(&buffer->rb_reqslock);
return req;
}
/**
* rpcrdma_create_rep - Allocate an rpcrdma_rep object
* @r_xprt: controlling transport
*
* Returns 0 on success or a negative errno on failure.
*/
int
rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_rep *rep;
int rc;
rc = -ENOMEM;
rep = kzalloc(sizeof(*rep), GFP_KERNEL);
if (rep == NULL)
goto out;
rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
DMA_FROM_DEVICE, GFP_KERNEL);
if (IS_ERR(rep->rr_rdmabuf)) {
rc = PTR_ERR(rep->rr_rdmabuf);
goto out_free;
}
xdr_buf_init(&rep->rr_hdrbuf, rep->rr_rdmabuf->rg_base,
rdmab_length(rep->rr_rdmabuf));
rep->rr_cqe.done = rpcrdma_wc_receive;
rep->rr_rxprt = r_xprt;
INIT_WORK(&rep->rr_work, rpcrdma_deferred_completion);
rep->rr_recv_wr.next = NULL;
rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
rep->rr_recv_wr.num_sge = 1;
spin_lock(&buf->rb_lock);
list_add(&rep->rr_list, &buf->rb_recv_bufs);
spin_unlock(&buf->rb_lock);
return 0;
out_free:
kfree(rep);
out:
dprintk("RPC: %s: reply buffer %d alloc failed\n",
__func__, rc);
return rc;
}
int
rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
int i, rc;
buf->rb_max_requests = r_xprt->rx_data.max_requests;
buf->rb_bc_srv_max_requests = 0;
spin_lock_init(&buf->rb_mrlock);
spin_lock_init(&buf->rb_lock);
spin_lock_init(&buf->rb_recovery_lock);
INIT_LIST_HEAD(&buf->rb_mrs);
INIT_LIST_HEAD(&buf->rb_all);
INIT_LIST_HEAD(&buf->rb_stale_mrs);
INIT_DELAYED_WORK(&buf->rb_refresh_worker,
rpcrdma_mr_refresh_worker);
INIT_DELAYED_WORK(&buf->rb_recovery_worker,
rpcrdma_mr_recovery_worker);
rpcrdma_mrs_create(r_xprt);
INIT_LIST_HEAD(&buf->rb_send_bufs);
INIT_LIST_HEAD(&buf->rb_allreqs);
spin_lock_init(&buf->rb_reqslock);
for (i = 0; i < buf->rb_max_requests; i++) {
struct rpcrdma_req *req;
req = rpcrdma_create_req(r_xprt);
if (IS_ERR(req)) {
dprintk("RPC: %s: request buffer %d alloc"
" failed\n", __func__, i);
rc = PTR_ERR(req);
goto out;
}
list_add(&req->rl_list, &buf->rb_send_bufs);
}
INIT_LIST_HEAD(&buf->rb_recv_bufs);
for (i = 0; i <= buf->rb_max_requests; i++) {
rc = rpcrdma_create_rep(r_xprt);
if (rc)
goto out;
}
rc = rpcrdma_sendctxs_create(r_xprt);
if (rc)
goto out;
return 0;
out:
rpcrdma_buffer_destroy(buf);
return rc;
}
static struct rpcrdma_req *
rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
{
struct rpcrdma_req *req;
req = list_first_entry(&buf->rb_send_bufs,
struct rpcrdma_req, rl_list);
list_del_init(&req->rl_list);
return req;
}
static struct rpcrdma_rep *
rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
{
struct rpcrdma_rep *rep;
rep = list_first_entry(&buf->rb_recv_bufs,
struct rpcrdma_rep, rr_list);
list_del(&rep->rr_list);
return rep;
}
static void
rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
{
rpcrdma_free_regbuf(rep->rr_rdmabuf);
kfree(rep);
}
void
rpcrdma_destroy_req(struct rpcrdma_req *req)
{
rpcrdma_free_regbuf(req->rl_recvbuf);
rpcrdma_free_regbuf(req->rl_sendbuf);
rpcrdma_free_regbuf(req->rl_rdmabuf);
kfree(req);
}
static void
rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
{
struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
rx_buf);
struct rpcrdma_ia *ia = rdmab_to_ia(buf);
struct rpcrdma_mr *mr;
unsigned int count;
count = 0;
spin_lock(&buf->rb_mrlock);
while (!list_empty(&buf->rb_all)) {
mr = list_entry(buf->rb_all.next, struct rpcrdma_mr, mr_all);
list_del(&mr->mr_all);
spin_unlock(&buf->rb_mrlock);
ia->ri_ops->ro_release_mr(mr);
count++;
spin_lock(&buf->rb_mrlock);
}
spin_unlock(&buf->rb_mrlock);
r_xprt->rx_stats.mrs_allocated = 0;
dprintk("RPC: %s: released %u MRs\n", __func__, count);
}
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
cancel_delayed_work_sync(&buf->rb_recovery_worker);
cancel_delayed_work_sync(&buf->rb_refresh_worker);
rpcrdma_sendctxs_destroy(buf);
while (!list_empty(&buf->rb_recv_bufs)) {
struct rpcrdma_rep *rep;
rep = rpcrdma_buffer_get_rep_locked(buf);
rpcrdma_destroy_rep(rep);
}
buf->rb_send_count = 0;
spin_lock(&buf->rb_reqslock);
while (!list_empty(&buf->rb_allreqs)) {
struct rpcrdma_req *req;
req = list_first_entry(&buf->rb_allreqs,
struct rpcrdma_req, rl_all);
list_del(&req->rl_all);
spin_unlock(&buf->rb_reqslock);
rpcrdma_destroy_req(req);
spin_lock(&buf->rb_reqslock);
}
spin_unlock(&buf->rb_reqslock);
buf->rb_recv_count = 0;
rpcrdma_mrs_destroy(buf);
}
/**
* rpcrdma_mr_get - Allocate an rpcrdma_mr object
* @r_xprt: controlling transport
*
* Returns an initialized rpcrdma_mr or NULL if no free
* rpcrdma_mr objects are available.
*/
struct rpcrdma_mr *
rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_mr *mr = NULL;
spin_lock(&buf->rb_mrlock);
if (!list_empty(&buf->rb_mrs))
mr = rpcrdma_mr_pop(&buf->rb_mrs);
spin_unlock(&buf->rb_mrlock);
if (!mr)
goto out_nomrs;
return mr;
out_nomrs:
trace_xprtrdma_nomrs(r_xprt);
if (r_xprt->rx_ep.rep_connected != -ENODEV)
schedule_delayed_work(&buf->rb_refresh_worker, 0);
/* Allow the reply handler and refresh worker to run */
cond_resched();
return NULL;
}
static void
__rpcrdma_mr_put(struct rpcrdma_buffer *buf, struct rpcrdma_mr *mr)
{
spin_lock(&buf->rb_mrlock);
rpcrdma_mr_push(mr, &buf->rb_mrs);
spin_unlock(&buf->rb_mrlock);
}
/**
* rpcrdma_mr_put - Release an rpcrdma_mr object
* @mr: object to release
*
*/
void
rpcrdma_mr_put(struct rpcrdma_mr *mr)
{
__rpcrdma_mr_put(&mr->mr_xprt->rx_buf, mr);
}
/**
* rpcrdma_mr_unmap_and_put - DMA unmap an MR and release it
* @mr: object to release
*
*/
void
rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr)
{
struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
trace_xprtrdma_dma_unmap(mr);
ib_dma_unmap_sg(r_xprt->rx_ia.ri_device,
mr->mr_sg, mr->mr_nents, mr->mr_dir);
__rpcrdma_mr_put(&r_xprt->rx_buf, mr);
}
static struct rpcrdma_rep *
rpcrdma_buffer_get_rep(struct rpcrdma_buffer *buffers)
{
/* If an RPC previously completed without a reply (say, a
* credential problem or a soft timeout occurs) then hold off
* on supplying more Receive buffers until the number of new
* pending RPCs catches up to the number of posted Receives.
*/
if (unlikely(buffers->rb_send_count < buffers->rb_recv_count))
return NULL;
if (unlikely(list_empty(&buffers->rb_recv_bufs)))
return NULL;
buffers->rb_recv_count++;
return rpcrdma_buffer_get_rep_locked(buffers);
}
/*
* Get a set of request/reply buffers.
*
* Reply buffer (if available) is attached to send buffer upon return.
*/
struct rpcrdma_req *
rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
{
struct rpcrdma_req *req;
spin_lock(&buffers->rb_lock);
if (list_empty(&buffers->rb_send_bufs))
goto out_reqbuf;
buffers->rb_send_count++;
req = rpcrdma_buffer_get_req_locked(buffers);
req->rl_reply = rpcrdma_buffer_get_rep(buffers);
spin_unlock(&buffers->rb_lock);
return req;
out_reqbuf:
spin_unlock(&buffers->rb_lock);
return NULL;
}
/*
* Put request/reply buffers back into pool.
* Pre-decrement counter/array index.
*/
void
rpcrdma_buffer_put(struct rpcrdma_req *req)
{
struct rpcrdma_buffer *buffers = req->rl_buffer;
struct rpcrdma_rep *rep = req->rl_reply;
req->rl_reply = NULL;
spin_lock(&buffers->rb_lock);
buffers->rb_send_count--;
list_add_tail(&req->rl_list, &buffers->rb_send_bufs);
if (rep) {
buffers->rb_recv_count--;
list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
}
spin_unlock(&buffers->rb_lock);
}
/*
* Recover reply buffers from pool.
* This happens when recovering from disconnect.
*/
void
rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
{
struct rpcrdma_buffer *buffers = req->rl_buffer;
spin_lock(&buffers->rb_lock);
req->rl_reply = rpcrdma_buffer_get_rep(buffers);
spin_unlock(&buffers->rb_lock);
}
/*
* Put reply buffers back into pool when not attached to
* request. This happens in error conditions.
*/
void
rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
{
struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
spin_lock(&buffers->rb_lock);
buffers->rb_recv_count--;
list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
spin_unlock(&buffers->rb_lock);
}
/**
* rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
* @size: size of buffer to be allocated, in bytes
* @direction: direction of data movement
* @flags: GFP flags
*
* Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
* can be persistently DMA-mapped for I/O.
*
* xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
* receiving the payload of RDMA RECV operations. During Long Calls
* or Replies they may be registered externally via ro_map.
*/
struct rpcrdma_regbuf *
rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
gfp_t flags)
{
struct rpcrdma_regbuf *rb;
rb = kmalloc(sizeof(*rb) + size, flags);
if (rb == NULL)
return ERR_PTR(-ENOMEM);
rb->rg_device = NULL;
rb->rg_direction = direction;
rb->rg_iov.length = size;
return rb;
}
/**
* __rpcrdma_map_regbuf - DMA-map a regbuf
* @ia: controlling rpcrdma_ia
* @rb: regbuf to be mapped
*/
bool
__rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
{
struct ib_device *device = ia->ri_device;
if (rb->rg_direction == DMA_NONE)
return false;
rb->rg_iov.addr = ib_dma_map_single(device,
(void *)rb->rg_base,
rdmab_length(rb),
rb->rg_direction);
if (ib_dma_mapping_error(device, rdmab_addr(rb)))
return false;
rb->rg_device = device;
rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
return true;
}
static void
rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb)
{
if (!rb)
return;
if (!rpcrdma_regbuf_is_mapped(rb))
return;
ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb),
rdmab_length(rb), rb->rg_direction);
rb->rg_device = NULL;
}
/**
* rpcrdma_free_regbuf - deregister and free registered buffer
* @rb: regbuf to be deregistered and freed
*/
void
rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
{
rpcrdma_dma_unmap_regbuf(rb);
kfree(rb);
}
/*
* Prepost any receive buffer, then post send.
*
* Receive buffer is donated to hardware, reclaimed upon recv completion.
*/
int
rpcrdma_ep_post(struct rpcrdma_ia *ia,
struct rpcrdma_ep *ep,
struct rpcrdma_req *req)
{
struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
int rc;
if (req->rl_reply) {
rc = rpcrdma_ep_post_recv(ia, req->rl_reply);
if (rc)
return rc;
req->rl_reply = NULL;
}
if (!ep->rep_send_count ||
test_bit(RPCRDMA_REQ_F_TX_RESOURCES, &req->rl_flags)) {
send_wr->send_flags |= IB_SEND_SIGNALED;
ep->rep_send_count = ep->rep_send_batch;
} else {
send_wr->send_flags &= ~IB_SEND_SIGNALED;
--ep->rep_send_count;
}
rc = ia->ri_ops->ro_send(ia, req);
trace_xprtrdma_post_send(req, rc);
if (rc)
return -ENOTCONN;
return 0;
}
int
rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
struct rpcrdma_rep *rep)
{
struct ib_recv_wr *recv_wr_fail;
int rc;
if (!rpcrdma_dma_map_regbuf(ia, rep->rr_rdmabuf))
goto out_map;
rc = ib_post_recv(ia->ri_id->qp, &rep->rr_recv_wr, &recv_wr_fail);
trace_xprtrdma_post_recv(rep, rc);
if (rc)
return -ENOTCONN;
return 0;
out_map:
pr_err("rpcrdma: failed to DMA map the Receive buffer\n");
return -EIO;
}
/**
* rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
* @r_xprt: transport associated with these backchannel resources
* @count: minimum number of incoming requests expected
*
* Returns zero if all requested buffers were posted, or a negative errno.
*/
int
rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
{
struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_rep *rep;
int rc;
while (count--) {
spin_lock(&buffers->rb_lock);
if (list_empty(&buffers->rb_recv_bufs))
goto out_reqbuf;
rep = rpcrdma_buffer_get_rep_locked(buffers);
spin_unlock(&buffers->rb_lock);
rc = rpcrdma_ep_post_recv(ia, rep);
if (rc)
goto out_rc;
}
return 0;
out_reqbuf:
spin_unlock(&buffers->rb_lock);
trace_xprtrdma_noreps(r_xprt);
return -ENOMEM;
out_rc:
rpcrdma_recv_buffer_put(rep);
return rc;
}
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