linux_dsm_epyc7002/net/sunrpc/xprtrdma/verbs.c
Linus Torvalds 89e255678f A relatively quiet cycle for nfsd. The largest piece is an RDMA update
from Chuck Lever with new trace points, miscellaneous cleanups, and
 streamlining of the send and receive paths.  Other than that, some
 miscellaneous bugfixes.
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Merge tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "A relatively quiet cycle for nfsd.

  The largest piece is an RDMA update from Chuck Lever with new trace
  points, miscellaneous cleanups, and streamlining of the send and
  receive paths.

  Other than that, some miscellaneous bugfixes"

* tag 'nfsd-4.18' of git://linux-nfs.org/~bfields/linux: (26 commits)
  nfsd: fix error handling in nfs4_set_delegation()
  nfsd: fix potential use-after-free in nfsd4_decode_getdeviceinfo
  Fix 16-byte memory leak in gssp_accept_sec_context_upcall
  svcrdma: Fix incorrect return value/type in svc_rdma_post_recvs
  svcrdma: Remove unused svc_rdma_op_ctxt
  svcrdma: Persistently allocate and DMA-map Send buffers
  svcrdma: Simplify svc_rdma_send()
  svcrdma: Remove post_send_wr
  svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxt
  svcrdma: Introduce svc_rdma_send_ctxt
  svcrdma: Clean up Send SGE accounting
  svcrdma: Refactor svc_rdma_dma_map_buf
  svcrdma: Allocate recv_ctxt's on CPU handling Receives
  svcrdma: Persistently allocate and DMA-map Receive buffers
  svcrdma: Preserve Receive buffer until svc_rdma_sendto
  svcrdma: Simplify svc_rdma_recv_ctxt_put
  svcrdma: Remove sc_rq_depth
  svcrdma: Introduce svc_rdma_recv_ctxt
  svcrdma: Trace key RDMA API events
  svcrdma: Trace key RPC/RDMA protocol events
  ...
2018-06-12 09:49:33 -07:00

1642 lines
41 KiB
C

/*
* 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"
#include <trace/events/rpcrdma.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);
/* Ensure MW is not on any rl_registered list */
if (!list_empty(&mr->mr_list))
list_del(&mr->mr_list);
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;
}