linux/net/sunrpc/xprtrdma/verbs.c
Chuck Lever 2fa8f88d88 xprtrdma: Use new CQ API for RPC-over-RDMA client send CQs
Calling ib_poll_cq() to sort through WCs during a completion is a
common pattern amongst RDMA consumers. Since commit 14d3a3b249
("IB: add a proper completion queue abstraction"), WC sorting can
be handled by the IB core.

By converting to this new API, xprtrdma is made a better neighbor to
other RDMA consumers, as it allows the core to schedule the delivery
of completions more fairly amongst all active consumers.

Because each ib_cqe carries a pointer to a completion method, the
core can now post its own operations on a consumer's QP, and handle
the completions itself, without changes to the consumer.

Send completions were previously handled entirely in the completion
upcall handler (ie, deferring to a process context is unneeded).
Thus IB_POLL_SOFTIRQ is a direct replacement for the current
xprtrdma send code path.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2016-03-14 14:56:08 -04:00

1296 lines
32 KiB
C

/*
* 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/prefetch.h>
#include <linux/sunrpc/addr.h>
#include <asm/bitops.h>
#include <linux/module.h> /* try_module_get()/module_put() */
#include "xprt_rdma.h"
/*
* Globals/Macros
*/
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
/*
* internal functions
*/
static struct workqueue_struct *rpcrdma_receive_wq;
int
rpcrdma_alloc_wq(void)
{
struct workqueue_struct *recv_wq;
recv_wq = alloc_workqueue("xprtrdma_receive",
WQ_MEM_RECLAIM | WQ_UNBOUND | 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;
pr_err("RPC: %s: %s on device %s ep %p\n",
__func__, 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)
{
/* WARNING: Only wr_cqe and status are reliable at this point */
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);
}
static void
rpcrdma_receive_worker(struct work_struct *work)
{
struct rpcrdma_rep *rep =
container_of(work, struct rpcrdma_rep, rr_work);
rpcrdma_reply_handler(rep);
}
/* Perform basic sanity checking to avoid using garbage
* to update the credit grant value.
*/
static void
rpcrdma_update_granted_credits(struct rpcrdma_rep *rep)
{
struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf);
struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf;
u32 credits;
if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
return;
credits = be32_to_cpu(rmsgp->rm_credit);
if (credits == 0)
credits = 1; /* don't deadlock */
else if (credits > buffer->rb_max_requests)
credits = buffer->rb_max_requests;
atomic_set(&buffer->rb_credits, credits);
}
/**
* rpcrdma_receive_wc - Invoked by RDMA provider for each polled Receive WC
* @cq: completion queue (ignored)
* @wc: completed WR
*
*/
static void
rpcrdma_receive_wc(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 */
if (wc->status != IB_WC_SUCCESS)
goto out_fail;
/* status == SUCCESS means all fields in wc are trustworthy */
if (wc->opcode != IB_WC_RECV)
return;
dprintk("RPC: %s: rep %p opcode 'recv', length %u: success\n",
__func__, rep, wc->byte_len);
rep->rr_len = wc->byte_len;
ib_dma_sync_single_for_cpu(rep->rr_device,
rdmab_addr(rep->rr_rdmabuf),
rep->rr_len, DMA_FROM_DEVICE);
rpcrdma_update_granted_credits(rep);
out_schedule:
queue_work(rpcrdma_receive_wq, &rep->rr_work);
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);
rep->rr_len = RPCRDMA_BAD_LEN;
goto out_schedule;
}
static void
rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
{
struct ib_wc wc;
while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
rpcrdma_receive_wc(NULL, &wc);
}
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;
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
struct sockaddr *sap = (struct sockaddr *)&ep->rep_remote_addr;
#endif
struct ib_qp_attr *attr = &ia->ri_qp_attr;
struct ib_qp_init_attr *iattr = &ia->ri_qp_init_attr;
int connstate = 0;
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;
dprintk("RPC: %s: CM address resolution error, ep 0x%p\n",
__func__, ep);
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ROUTE_ERROR:
ia->ri_async_rc = -ENETUNREACH;
dprintk("RPC: %s: CM route resolution error, ep 0x%p\n",
__func__, ep);
complete(&ia->ri_done);
break;
case RDMA_CM_EVENT_ESTABLISHED:
connstate = 1;
ib_query_qp(ia->ri_id->qp, attr,
IB_QP_MAX_QP_RD_ATOMIC | IB_QP_MAX_DEST_RD_ATOMIC,
iattr);
dprintk("RPC: %s: %d responder resources"
" (%d initiator)\n",
__func__, attr->max_dest_rd_atomic,
attr->max_rd_atomic);
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:
connstate = -ECONNREFUSED;
goto connected;
case RDMA_CM_EVENT_DISCONNECTED:
connstate = -ECONNABORTED;
goto connected;
case RDMA_CM_EVENT_DEVICE_REMOVAL:
connstate = -ENODEV;
connected:
dprintk("RPC: %s: %sconnected\n",
__func__, connstate > 0 ? "" : "dis");
atomic_set(&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: %pIS:%u (ep 0x%p): %s\n",
__func__, sap, rpc_get_port(sap), ep,
rdma_event_msg(event->event));
break;
}
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
if (connstate == 1) {
int ird = attr->max_dest_rd_atomic;
int tird = ep->rep_remote_cma.responder_resources;
pr_info("rpcrdma: connection to %pIS:%u on %s, memreg '%s', %d credits, %d responders%s\n",
sap, rpc_get_port(sap),
ia->ri_device->name,
ia->ri_ops->ro_displayname,
xprt->rx_buf.rb_max_requests,
ird, ird < 4 && ird < tird / 2 ? " (low!)" : "");
} else if (connstate < 0) {
pr_info("rpcrdma: connection to %pIS:%u closed (%d)\n",
sap, rpc_get_port(sap), connstate);
}
#endif
return 0;
}
static void rpcrdma_destroy_id(struct rdma_cm_id *id)
{
if (id) {
module_put(id->device->owner);
rdma_destroy_id(id);
}
}
static struct rdma_cm_id *
rpcrdma_create_id(struct rpcrdma_xprt *xprt,
struct rpcrdma_ia *ia, struct sockaddr *addr)
{
struct rdma_cm_id *id;
int rc;
init_completion(&ia->ri_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, addr, RDMA_RESOLVE_TIMEOUT);
if (rc) {
dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
__func__, rc);
goto out;
}
wait_for_completion_interruptible_timeout(&ia->ri_done,
msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
/* FIXME:
* Until xprtrdma supports DEVICE_REMOVAL, the provider must
* be pinned while there are active NFS/RDMA mounts to prevent
* hangs and crashes at umount time.
*/
if (!ia->ri_async_rc && !try_module_get(id->device->owner)) {
dprintk("RPC: %s: Failed to get device module\n",
__func__);
ia->ri_async_rc = -ENODEV;
}
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 put;
}
wait_for_completion_interruptible_timeout(&ia->ri_done,
msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
rc = ia->ri_async_rc;
if (rc)
goto put;
return id;
put:
module_put(id->device->owner);
out:
rdma_destroy_id(id);
return ERR_PTR(rc);
}
/*
* Drain any cq, prior to teardown.
*/
static void
rpcrdma_clean_cq(struct ib_cq *cq)
{
struct ib_wc wc;
int count = 0;
while (1 == ib_poll_cq(cq, 1, &wc))
++count;
if (count)
dprintk("RPC: %s: flushed %d events (last 0x%x)\n",
__func__, count, wc.opcode);
}
/*
* Exported functions.
*/
/*
* Open and initialize an Interface Adapter.
* o initializes fields of struct rpcrdma_ia, including
* interface and provider attributes and protection zone.
*/
int
rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
{
struct rpcrdma_ia *ia = &xprt->rx_ia;
int rc;
ia->ri_dma_mr = NULL;
ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
if (IS_ERR(ia->ri_id)) {
rc = PTR_ERR(ia->ri_id);
goto out1;
}
ia->ri_device = ia->ri_id->device;
ia->ri_pd = ib_alloc_pd(ia->ri_device);
if (IS_ERR(ia->ri_pd)) {
rc = PTR_ERR(ia->ri_pd);
dprintk("RPC: %s: ib_alloc_pd() failed %i\n",
__func__, rc);
goto out2;
}
if (memreg == RPCRDMA_FRMR) {
if (!(ia->ri_device->attrs.device_cap_flags &
IB_DEVICE_MEM_MGT_EXTENSIONS) ||
(ia->ri_device->attrs.max_fast_reg_page_list_len == 0)) {
dprintk("RPC: %s: FRMR registration "
"not supported by HCA\n", __func__);
memreg = RPCRDMA_MTHCAFMR;
}
}
if (memreg == RPCRDMA_MTHCAFMR) {
if (!ia->ri_device->alloc_fmr) {
dprintk("RPC: %s: MTHCAFMR registration "
"not supported by HCA\n", __func__);
rc = -EINVAL;
goto out3;
}
}
switch (memreg) {
case RPCRDMA_FRMR:
ia->ri_ops = &rpcrdma_frwr_memreg_ops;
break;
case RPCRDMA_ALLPHYSICAL:
ia->ri_ops = &rpcrdma_physical_memreg_ops;
break;
case RPCRDMA_MTHCAFMR:
ia->ri_ops = &rpcrdma_fmr_memreg_ops;
break;
default:
printk(KERN_ERR "RPC: Unsupported memory "
"registration mode: %d\n", memreg);
rc = -ENOMEM;
goto out3;
}
dprintk("RPC: %s: memory registration strategy is '%s'\n",
__func__, ia->ri_ops->ro_displayname);
rwlock_init(&ia->ri_qplock);
return 0;
out3:
ib_dealloc_pd(ia->ri_pd);
ia->ri_pd = NULL;
out2:
rpcrdma_destroy_id(ia->ri_id);
ia->ri_id = NULL;
out1:
return rc;
}
/*
* Clean up/close an IA.
* o if event handles and PD have been initialized, free them.
* o close the IA
*/
void
rpcrdma_ia_close(struct rpcrdma_ia *ia)
{
dprintk("RPC: %s: entering\n", __func__);
if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
if (ia->ri_id->qp)
rdma_destroy_qp(ia->ri_id);
rpcrdma_destroy_id(ia->ri_id);
ia->ri_id = 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);
}
/*
* Create unconnected endpoint.
*/
int
rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
struct rpcrdma_create_data_internal *cdata)
{
struct ib_cq *sendcq, *recvcq;
unsigned int max_qp_wr;
int rc;
if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_IOVS) {
dprintk("RPC: %s: insufficient sge's available\n",
__func__);
return -ENOMEM;
}
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;
/* 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;
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_send_sge = RPCRDMA_MAX_IOVS;
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_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
if (ep->rep_cqinit <= 2)
ep->rep_cqinit = 0; /* always signal? */
INIT_CQCOUNT(ep);
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,
0, IB_POLL_SOFTIRQ);
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_SOFTIRQ);
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 */
/* RPC/RDMA does not use private data */
ep->rep_remote_cma.private_data = NULL;
ep->rep_remote_cma.private_data_len = 0;
/* Client offers RDMA Read but does not initiate */
ep->rep_remote_cma.initiator_depth = 0;
if (ia->ri_device->attrs.max_qp_rd_atom > 32) /* arbitrary but <= 255 */
ep->rep_remote_cma.responder_resources = 32;
else
ep->rep_remote_cma.responder_resources =
ia->ri_device->attrs.max_qp_rd_atom;
ep->rep_remote_cma.retry_count = 7;
ep->rep_remote_cma.flow_control = 0;
ep->rep_remote_cma.rnr_retry_count = 0;
return 0;
out2:
ib_free_cq(sendcq);
out1:
if (ia->ri_dma_mr)
ib_dereg_mr(ia->ri_dma_mr);
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)
{
int rc;
dprintk("RPC: %s: entering, connected is %d\n",
__func__, ep->rep_connected);
cancel_delayed_work_sync(&ep->rep_connect_worker);
if (ia->ri_id->qp)
rpcrdma_ep_disconnect(ep, ia);
rpcrdma_clean_cq(ep->rep_attr.recv_cq);
rpcrdma_clean_cq(ep->rep_attr.send_cq);
if (ia->ri_id->qp) {
rdma_destroy_qp(ia->ri_id);
ia->ri_id->qp = NULL;
}
ib_free_cq(ep->rep_attr.recv_cq);
ib_free_cq(ep->rep_attr.send_cq);
if (ia->ri_dma_mr) {
rc = ib_dereg_mr(ia->ri_dma_mr);
dprintk("RPC: %s: ib_dereg_mr returned %i\n",
__func__, rc);
}
}
/*
* Connect unconnected endpoint.
*/
int
rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
{
struct rdma_cm_id *id, *old;
int rc = 0;
int retry_count = 0;
if (ep->rep_connected != 0) {
struct rpcrdma_xprt *xprt;
retry:
dprintk("RPC: %s: reconnecting...\n", __func__);
rpcrdma_ep_disconnect(ep, ia);
rpcrdma_flush_cqs(ep);
xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
id = rpcrdma_create_id(xprt, ia,
(struct sockaddr *)&xprt->rx_data.addr);
if (IS_ERR(id)) {
rc = -EHOSTUNREACH;
goto out;
}
/* TEMP TEMP TEMP - fail if new device:
* Deregister/remarshal *all* requests!
* Close and recreate adapter, pd, etc!
* Re-determine all attributes still sane!
* More stuff I haven't thought of!
* Rrrgh!
*/
if (ia->ri_device != id->device) {
printk("RPC: %s: can't reconnect on "
"different device!\n", __func__);
rpcrdma_destroy_id(id);
rc = -ENETUNREACH;
goto out;
}
/* END TEMP */
rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
if (rc) {
dprintk("RPC: %s: rdma_create_qp failed %i\n",
__func__, rc);
rpcrdma_destroy_id(id);
rc = -ENETUNREACH;
goto out;
}
write_lock(&ia->ri_qplock);
old = ia->ri_id;
ia->ri_id = id;
write_unlock(&ia->ri_qplock);
rdma_destroy_qp(old);
rpcrdma_destroy_id(old);
} else {
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);
/* do not update ep->rep_connected */
return -ENETUNREACH;
}
}
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);
/*
* Check state. A non-peer reject indicates no listener
* (ECONNREFUSED), which may be a transient state. All
* others indicate a transport condition which has already
* undergone a best-effort.
*/
if (ep->rep_connected == -ECONNREFUSED &&
++retry_count <= RDMA_CONNECT_RETRY_MAX) {
dprintk("RPC: %s: non-peer_reject, retry\n", __func__);
goto retry;
}
if (ep->rep_connected <= 0) {
/* Sometimes, the only way to reliably connect to remote
* CMs is to use same nonzero values for ORD and IRD. */
if (retry_count++ <= RDMA_CONNECT_RETRY_MAX + 1 &&
(ep->rep_remote_cma.responder_resources == 0 ||
ep->rep_remote_cma.initiator_depth !=
ep->rep_remote_cma.responder_resources)) {
if (ep->rep_remote_cma.responder_resources == 0)
ep->rep_remote_cma.responder_resources = 1;
ep->rep_remote_cma.initiator_depth =
ep->rep_remote_cma.responder_resources;
goto retry;
}
rc = ep->rep_connected;
} else {
struct rpcrdma_xprt *r_xprt;
unsigned int extras;
dprintk("RPC: %s: connected\n", __func__);
r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
if (extras) {
rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
if (rc) {
pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
__func__, rc);
rc = 0;
}
}
}
out:
if (rc)
ep->rep_connected = rc;
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;
rpcrdma_flush_cqs(ep);
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);
dprintk("RPC: %s: after wait, %sconnected\n", __func__,
(ep->rep_connected == 1) ? "still " : "dis");
} else {
dprintk("RPC: %s: rdma_disconnect %i\n", __func__, rc);
ep->rep_connected = rc;
}
}
struct rpcrdma_req *
rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
struct rpcrdma_req *req;
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (req == NULL)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&req->rl_free);
spin_lock(&buffer->rb_reqslock);
list_add(&req->rl_all, &buffer->rb_allreqs);
spin_unlock(&buffer->rb_reqslock);
req->rl_cqe.done = rpcrdma_wc_send;
req->rl_buffer = &r_xprt->rx_buf;
return req;
}
struct rpcrdma_rep *
rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
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(ia, cdata->inline_rsize,
GFP_KERNEL);
if (IS_ERR(rep->rr_rdmabuf)) {
rc = PTR_ERR(rep->rr_rdmabuf);
goto out_free;
}
rep->rr_device = ia->ri_device;
rep->rr_cqe.done = rpcrdma_receive_wc;
rep->rr_rxprt = r_xprt;
INIT_WORK(&rep->rr_work, rpcrdma_receive_worker);
return rep;
out_free:
kfree(rep);
out:
return ERR_PTR(rc);
}
int
rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
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_lock);
atomic_set(&buf->rb_credits, 1);
rc = ia->ri_ops->ro_init(r_xprt);
if (rc)
goto out;
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;
}
req->rl_backchannel = false;
list_add(&req->rl_free, &buf->rb_send_bufs);
}
INIT_LIST_HEAD(&buf->rb_recv_bufs);
for (i = 0; i < buf->rb_max_requests + 2; i++) {
struct rpcrdma_rep *rep;
rep = rpcrdma_create_rep(r_xprt);
if (IS_ERR(rep)) {
dprintk("RPC: %s: reply buffer %d alloc failed\n",
__func__, i);
rc = PTR_ERR(rep);
goto out;
}
list_add(&rep->rr_list, &buf->rb_recv_bufs);
}
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_free);
list_del(&req->rl_free);
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_ia *ia, struct rpcrdma_rep *rep)
{
rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
kfree(rep);
}
void
rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
{
rpcrdma_free_regbuf(ia, req->rl_sendbuf);
rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
kfree(req);
}
void
rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
{
struct rpcrdma_ia *ia = rdmab_to_ia(buf);
while (!list_empty(&buf->rb_recv_bufs)) {
struct rpcrdma_rep *rep;
rep = rpcrdma_buffer_get_rep_locked(buf);
rpcrdma_destroy_rep(ia, rep);
}
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(ia, req);
spin_lock(&buf->rb_reqslock);
}
spin_unlock(&buf->rb_reqslock);
ia->ri_ops->ro_destroy(buf);
}
struct rpcrdma_mw *
rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
struct rpcrdma_mw *mw = NULL;
spin_lock(&buf->rb_mwlock);
if (!list_empty(&buf->rb_mws)) {
mw = list_first_entry(&buf->rb_mws,
struct rpcrdma_mw, mw_list);
list_del_init(&mw->mw_list);
}
spin_unlock(&buf->rb_mwlock);
if (!mw)
pr_err("RPC: %s: no MWs available\n", __func__);
return mw;
}
void
rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
{
struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
spin_lock(&buf->rb_mwlock);
list_add_tail(&mw->mw_list, &buf->rb_mws);
spin_unlock(&buf->rb_mwlock);
}
/*
* 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;
req = rpcrdma_buffer_get_req_locked(buffers);
if (list_empty(&buffers->rb_recv_bufs))
goto out_repbuf;
req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
spin_unlock(&buffers->rb_lock);
return req;
out_reqbuf:
spin_unlock(&buffers->rb_lock);
pr_warn("RPC: %s: out of request buffers\n", __func__);
return NULL;
out_repbuf:
spin_unlock(&buffers->rb_lock);
pr_warn("RPC: %s: out of reply buffers\n", __func__);
req->rl_reply = NULL;
return req;
}
/*
* 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_niovs = 0;
req->rl_reply = NULL;
spin_lock(&buffers->rb_lock);
list_add_tail(&req->rl_free, &buffers->rb_send_bufs);
if (rep)
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);
if (!list_empty(&buffers->rb_recv_bufs))
req->rl_reply = rpcrdma_buffer_get_rep_locked(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);
list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
spin_unlock(&buffers->rb_lock);
}
/*
* Wrappers for internal-use kmalloc memory registration, used by buffer code.
*/
void
rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
{
dprintk("RPC: map_one: offset %p iova %llx len %zu\n",
seg->mr_offset,
(unsigned long long)seg->mr_dma, seg->mr_dmalen);
}
/**
* rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers
* @ia: controlling rpcrdma_ia
* @size: size of buffer to be allocated, in bytes
* @flags: GFP flags
*
* Returns pointer to private header of an area of internally
* registered memory, or an ERR_PTR. The registered buffer follows
* the end of the private header.
*
* xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
* receiving the payload of RDMA RECV operations. regbufs are not
* used for RDMA READ/WRITE operations, thus are registered only for
* LOCAL access.
*/
struct rpcrdma_regbuf *
rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
{
struct rpcrdma_regbuf *rb;
struct ib_sge *iov;
rb = kmalloc(sizeof(*rb) + size, flags);
if (rb == NULL)
goto out;
iov = &rb->rg_iov;
iov->addr = ib_dma_map_single(ia->ri_device,
(void *)rb->rg_base, size,
DMA_BIDIRECTIONAL);
if (ib_dma_mapping_error(ia->ri_device, iov->addr))
goto out_free;
iov->length = size;
iov->lkey = ia->ri_pd->local_dma_lkey;
rb->rg_size = size;
rb->rg_owner = NULL;
return rb;
out_free:
kfree(rb);
out:
return ERR_PTR(-ENOMEM);
}
/**
* rpcrdma_free_regbuf - deregister and free registered buffer
* @ia: controlling rpcrdma_ia
* @rb: regbuf to be deregistered and freed
*/
void
rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
{
struct ib_sge *iov;
if (!rb)
return;
iov = &rb->rg_iov;
ib_dma_unmap_single(ia->ri_device,
iov->addr, iov->length, DMA_BIDIRECTIONAL);
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_device *device = ia->ri_device;
struct ib_send_wr send_wr, *send_wr_fail;
struct rpcrdma_rep *rep = req->rl_reply;
struct ib_sge *iov = req->rl_send_iov;
int i, rc;
if (rep) {
rc = rpcrdma_ep_post_recv(ia, ep, rep);
if (rc)
goto out;
req->rl_reply = NULL;
}
send_wr.next = NULL;
send_wr.wr_cqe = &req->rl_cqe;
send_wr.sg_list = iov;
send_wr.num_sge = req->rl_niovs;
send_wr.opcode = IB_WR_SEND;
for (i = 0; i < send_wr.num_sge; i++)
ib_dma_sync_single_for_device(device, iov[i].addr,
iov[i].length, DMA_TO_DEVICE);
dprintk("RPC: %s: posting %d s/g entries\n",
__func__, send_wr.num_sge);
if (DECR_CQCOUNT(ep) > 0)
send_wr.send_flags = 0;
else { /* Provider must take a send completion every now and then */
INIT_CQCOUNT(ep);
send_wr.send_flags = IB_SEND_SIGNALED;
}
rc = ib_post_send(ia->ri_id->qp, &send_wr, &send_wr_fail);
if (rc)
dprintk("RPC: %s: ib_post_send returned %i\n", __func__,
rc);
out:
return rc;
}
/*
* (Re)post a receive buffer.
*/
int
rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
struct rpcrdma_ep *ep,
struct rpcrdma_rep *rep)
{
struct ib_recv_wr recv_wr, *recv_wr_fail;
int rc;
recv_wr.next = NULL;
recv_wr.wr_cqe = &rep->rr_cqe;
recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
recv_wr.num_sge = 1;
ib_dma_sync_single_for_cpu(ia->ri_device,
rdmab_addr(rep->rr_rdmabuf),
rdmab_length(rep->rr_rdmabuf),
DMA_BIDIRECTIONAL);
rc = ib_post_recv(ia->ri_id->qp, &recv_wr, &recv_wr_fail);
if (rc)
dprintk("RPC: %s: ib_post_recv returned %i\n", __func__,
rc);
return rc;
}
/**
* rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
* @r_xprt: transport associated with these backchannel resources
* @min_reqs: 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_ep *ep = &r_xprt->rx_ep;
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, ep, rep);
if (rc)
goto out_rc;
}
return 0;
out_reqbuf:
spin_unlock(&buffers->rb_lock);
pr_warn("%s: no extra receive buffers\n", __func__);
return -ENOMEM;
out_rc:
rpcrdma_recv_buffer_put(rep);
return rc;
}
/* How many chunk list items fit within our inline buffers?
*/
unsigned int
rpcrdma_max_segments(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
int bytes, segments;
bytes = min_t(unsigned int, cdata->inline_wsize, cdata->inline_rsize);
bytes -= RPCRDMA_HDRLEN_MIN;
if (bytes < sizeof(struct rpcrdma_segment) * 2) {
pr_warn("RPC: %s: inline threshold too small\n",
__func__);
return 0;
}
segments = 1 << (fls(bytes / sizeof(struct rpcrdma_segment)) - 1);
dprintk("RPC: %s: max chunk list size = %d segments\n",
__func__, segments);
return segments;
}