verbs.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 <asm/bitops.h>

#include "xprt_rdma.h"

/*
 * Globals/Macros
 */

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_TRANS
#endif

static void rpcrdma_reset_frmrs(struct rpcrdma_ia *);
static void rpcrdma_reset_fmrs(struct rpcrdma_ia *);

/*
 * internal functions
 */

/*
 * handle replies in tasklet context, using a single, global list
 * rdma tasklet function -- just turn around and call the func
 * for all replies on the list
 */

static DEFINE_SPINLOCK(rpcrdma_tk_lock_g);
static LIST_HEAD(rpcrdma_tasklets_g);

static void
rpcrdma_run_tasklet(unsigned long data)
{
	struct rpcrdma_rep *rep;
	void (*func)(struct rpcrdma_rep *);
	unsigned long flags;

	data = data;
	spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
	while (!list_empty(&rpcrdma_tasklets_g)) {
		rep = list_entry(rpcrdma_tasklets_g.next,
				 struct rpcrdma_rep, rr_list);
		list_del(&rep->rr_list);
		func = rep->rr_func;
		rep->rr_func = NULL;
		spin_unlock_irqrestore(&rpcrdma_tk_lock_g, flags);

		if (func)
			func(rep);
		else
			rpcrdma_recv_buffer_put(rep);

		spin_lock_irqsave(&rpcrdma_tk_lock_g, flags);
	}
	spin_unlock_irqrestore(&rpcrdma_tk_lock_g, flags);
}

static DECLARE_TASKLET(rpcrdma_tasklet_g, rpcrdma_run_tasklet, 0UL);

static void
rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
{
	struct rpcrdma_ep *ep = context;

	dprintk("RPC:       %s: QP error %X on device %s ep %p\n",
		__func__, event->event, event->device->name, context);
	if (ep->rep_connected == 1) {
		ep->rep_connected = -EIO;
		ep->rep_func(ep);
		wake_up_all(&ep->rep_connect_wait);
	}
}

static void
rpcrdma_cq_async_error_upcall(struct ib_event *event, void *context)
{
	struct rpcrdma_ep *ep = context;

	dprintk("RPC:       %s: CQ error %X on device %s ep %p\n",
		__func__, event->event, event->device->name, context);
	if (ep->rep_connected == 1) {
		ep->rep_connected = -EIO;
		ep->rep_func(ep);
		wake_up_all(&ep->rep_connect_wait);
	}
}

static void
rpcrdma_sendcq_process_wc(struct ib_wc *wc)
{
	struct rpcrdma_mw *frmr = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;

	dprintk("RPC:       %s: frmr %p status %X opcode %d\n",
		__func__, frmr, wc->status, wc->opcode);

	if (wc->wr_id == 0ULL)
		return;
	if (wc->status != IB_WC_SUCCESS)
		frmr->r.frmr.fr_state = FRMR_IS_STALE;
}

static int
rpcrdma_sendcq_poll(struct ib_cq *cq, struct rpcrdma_ep *ep)
{
	struct ib_wc *wcs;
	int budget, count, rc;

	budget = RPCRDMA_WC_BUDGET / RPCRDMA_POLLSIZE;
	do {
		wcs = ep->rep_send_wcs;

		rc = ib_poll_cq(cq, RPCRDMA_POLLSIZE, wcs);
		if (rc <= 0)
			return rc;

		count = rc;
		while (count-- > 0)
			rpcrdma_sendcq_process_wc(wcs++);
	} while (rc == RPCRDMA_POLLSIZE && --budget);
	return 0;
}

/*
 * Handle send, fast_reg_mr, and local_inv completions.
 *
 * Send events are typically suppressed and thus do not result
 * in an upcall. Occasionally one is signaled, however. This
 * prevents the provider's completion queue from wrapping and
 * losing a completion.
 */
static void
rpcrdma_sendcq_upcall(struct ib_cq *cq, void *cq_context)
{
	struct rpcrdma_ep *ep = (struct rpcrdma_ep *)cq_context;
	int rc;

	rc = rpcrdma_sendcq_poll(cq, ep);
	if (rc) {
		dprintk("RPC:       %s: ib_poll_cq failed: %i\n",
			__func__, rc);
		return;
	}

	rc = ib_req_notify_cq(cq,
			IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
	if (rc == 0)
		return;
	if (rc < 0) {
		dprintk("RPC:       %s: ib_req_notify_cq failed: %i\n",
			__func__, rc);
		return;