path: root/net/rds/ib_recv.c

/*
 * Copyright (c) 2006 Oracle.  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
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <rdma/rdma_cm.h>

#include "rds.h"
#include "ib.h"

static struct kmem_cache *rds_ib_incoming_slab;
static struct kmem_cache *rds_ib_frag_slab;
static atomic_t	rds_ib_allocation = ATOMIC_INIT(0);

void rds_ib_recv_init_ring(struct rds_ib_connection *ic)
{
	struct rds_ib_recv_work *recv;
	u32 i;

	for (i = 0, recv = ic->i_recvs; i < ic->i_recv_ring.w_nr; i++, recv++) {
		struct ib_sge *sge;

		recv->r_ibinc = NULL;
		recv->r_frag = NULL;

		recv->r_wr.next = NULL;
		recv->r_wr.wr_id = i;
		recv->r_wr.sg_list = recv->r_sge;
		recv->r_wr.num_sge = RDS_IB_RECV_SGE;

		sge = &recv->r_sge[0];
		sge->addr = ic->i_recv_hdrs_dma + (i * sizeof(struct rds_header));
		sge->length = sizeof(struct rds_header);
		sge->lkey = ic->i_mr->lkey;

		sge = &recv->r_sge[1];
		sge->addr = 0;
		sge->length = RDS_FRAG_SIZE;
		sge->lkey = ic->i_mr->lkey;
	}
}

/*
 * The entire 'from' list, including the from element itself, is put on
 * to the tail of the 'to' list.
 */
static void list_splice_entire_tail(struct list_head *from,
				    struct list_head *to)
{
	struct list_head *from_last = from->prev;

	list_splice_tail(from_last, to);
	list_add_tail(from_last, to);
}

static void rds_ib_cache_xfer_to_ready(struct rds_ib_refill_cache *cache)
{
	struct list_head *tmp;

	tmp = xchg(&cache->xfer, NULL);
	if (tmp) {
		if (cache->ready)
			list_splice_entire_tail(tmp, cache->ready);
		else
			cache->ready = tmp;
	}
}

static int rds_ib_recv_alloc_cache(struct rds_ib_refill_cache *cache)
{
	struct rds_ib_cache_head *head;
	int cpu;

	cache->percpu = alloc_percpu(struct rds_ib_cache_head);
	if (!cache->percpu)
	       return -ENOMEM;

	for_each_possible_cpu(cpu) {
		head = per_cpu_ptr(cache->percpu, cpu);
		head->first = NULL;
		head->count = 0;
	}
	cache->xfer = NULL;
	cache->ready = NULL;

	return 0;
}

int rds_ib_recv_alloc_caches(struct rds_ib_connection *ic)
{
	int ret;

	ret = rds_ib_recv_alloc_cache(&ic->i_cache_incs);
	if (!ret) {
		ret = rds_ib_recv_alloc_cache(&ic->i_cache_frags);
		if (ret)
			free_percpu(ic->i_cache_incs.percpu);
	}

	return ret;
}

static void rds_ib_cache_splice_all_lists(struct rds_ib_refill_cache *cache,
					  struct list_head *caller_list)
{
	struct rds_ib_cache_head *head;
	int cpu;

	for_each_possible_cpu(cpu) {
		head = per_cpu_ptr(cache->percpu, cpu