svc_rdma.c

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/*
 * Copyright (c) 2005-2006 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.
 *
 * Author: Tom Tucker <[email protected]>
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/sysctl.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/svc_rdma.h>
#include "xprt_rdma.h"

#define RPCDBG_FACILITY RPCDBG_SVCXPRT

/* RPC/RDMA parameters */
unsigned int svcrdma_ord = RPCRDMA_ORD;
static unsigned int min_ord = 1;
static unsigned int max_ord = 4096;
unsigned int svcrdma_max_requests = RPCRDMA_MAX_REQUESTS;
static unsigned int min_max_requests = 4;
static unsigned int max_max_requests = 16384;
unsigned int svcrdma_max_req_size = RPCRDMA_MAX_REQ_SIZE;
static unsigned int min_max_inline = 4096;
static unsigned int max_max_inline = 65536;

atomic_t rdma_stat_recv;
atomic_t rdma_stat_read;
atomic_t rdma_stat_write;
atomic_t rdma_stat_sq_starve;
atomic_t rdma_stat_rq_starve;
atomic_t rdma_stat_rq_poll;
atomic_t rdma_stat_rq_prod;
atomic_t rdma_stat_sq_poll;
atomic_t rdma_stat_sq_prod;

/* Temporary NFS request map and context caches */
struct kmem_cache *svc_rdma_map_cachep;
struct kmem_cache *svc_rdma_ctxt_cachep;

struct workqueue_struct *svc_rdma_wq;

/*
 * This function implements reading and resetting an atomic_t stat
 * variable through read/write to a proc file. Any write to the file
 * resets the associated statistic to zero. Any read returns it's
 * current value.
 */
static int read_reset_stat(ctl_table *table, int write,
               void __user *buffer, size_t *lenp,
               loff_t *ppos)
{
    atomic_t *stat = (atomic_t *)table->data;

    if (!stat)
        return -EINVAL;

    if (write)
        atomic_set(stat, 0);
    else {
        char str_buf[32];
        char *data;
        int len = snprintf(str_buf, 32, "%d\n", atomic_read(stat));
        if (len >= 32)
            return -EFAULT;
        len = strlen(str_buf);
        if (*ppos > len) {
            *lenp = 0;
            return 0;
        }
        data = &str_buf[*ppos];
        len -= *ppos;
        if (len > *lenp)
            len = *lenp;
        if (len && copy_to_user(buffer, str_buf, len))
            return -EFAULT;
        *lenp = len;
        *ppos += len;
    }
    return 0;
}

static struct ctl_table_header *svcrdma_table_header;
static ctl_table svcrdma_parm_table[] = {
    {
        .procname   = "max_requests",
        .data       = &svcrdma_max_requests,
        .maxlen     = sizeof(unsigned int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec_minmax,
        .extra1     = &min_max_requests,
        .extra2     = &max_max_requests
    },
    {
        .procname   = "max_req_size",
        .data       = &svcrdma_max_req_size,
        .maxlen     = sizeof(unsigned int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec_minmax,
        .extra1     = &min_max_inline,
        .extra2     = &max_max_inline
    },
    {
        .procname   = "max_outbound_read_requests",
        .data       = &svcrdma_ord,
        .maxlen     = sizeof(unsigned int),
        .mode       = 0644,
        .proc_handler   = proc_dointvec_minmax,
        .extra1     = &min_ord,
        .extra2     = &max_ord,
    },

    {
        .procname   = "rdma_stat_read",
        .data       = &rdma_stat_read,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_recv",
        .data       = &rdma_stat_recv,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_write",
        .data       = &rdma_stat_write,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_sq_starve",
        .data       = &rdma_stat_sq_starve,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_rq_starve",
        .data       = &rdma_stat_rq_starve,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_rq_poll",
        .data       = &rdma_stat_rq_poll,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_rq_prod",
        .data       = &rdma_stat_rq_prod,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_sq_poll",
        .data       = &rdma_stat_sq_poll,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    {
        .procname   = "rdma_stat_sq_prod",
        .data       = &rdma_stat_sq_prod,
        .maxlen     = sizeof(atomic_t),
        .mode       = 0644,
        .proc_handler   = read_reset_stat,
    },
    { },
};

static ctl_table svcrdma_table[] = {
    {
        .procname   = "svc_rdma",
        .mode       = 0555,
        .child      = svcrdma_parm_table
    },
    { },
};

static ctl_table svcrdma_root_table[] = {
    {
        .procname   = "sunrpc",
        .mode       = 0555,
        .child      = svcrdma_table
    },
    { },
};

void svc_rdma_cleanup(void)
{
    dprintk("SVCRDMA Module Removed, deregister RPC RDMA transport\n");
    destroy_workqueue(svc_rdma_wq);
    if (svcrdma_table_header) {
        unregister_sysctl_table(svcrdma_table_header);
        svcrdma_table_header = NULL;
    }
    svc_unreg_xprt_class(&svc_rdma_class);
    kmem_cache_destroy(svc_rdma_map_cachep);
    kmem_cache_destroy(svc_rdma_ctxt_cachep);
}

int svc_rdma_init(void)
{
    dprintk("SVCRDMA Module Init, register RPC RDMA transport\n");
    dprintk("\tsvcrdma_ord      : %d\n", svcrdma_ord);
    dprintk("\tmax_requests     : %d\n", svcrdma_max_requests);
    dprintk("\tsq_depth         : %d\n",
        svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT);
    dprintk("\tmax_inline       : %d\n", svcrdma_max_req_size);

    svc_rdma_wq = alloc_workqueue("svc_rdma", 0, 0);
    if (!svc_rdma_wq)
        return -ENOMEM;

    if (!svcrdma_table_header)
        svcrdma_table_header =
            register_sysctl_table(svcrdma_root_table);

    /* Create the temporary map cache */
    svc_rdma_map_cachep = kmem_cache_create("svc_rdma_map_cache",
                        sizeof(struct svc_rdma_req_map),
                        0,
                        SLAB_HWCACHE_ALIGN,
                        NULL);
    if (!svc_rdma_map_cachep) {
        printk(KERN_INFO "Could not allocate map cache.\n");
        goto err0;
    }

    /* Create the temporary context cache */
    svc_rdma_ctxt_cachep =
        kmem_cache_create("svc_rdma_ctxt_cache",
                  sizeof(struct svc_rdma_op_ctxt),
                  0,
                  SLAB_HWCACHE_ALIGN,
                  NULL);
    if (!svc_rdma_ctxt_cachep) {
        printk(KERN_INFO "Could not allocate WR ctxt cache.\n");
        goto err1;
    }

    /* Register RDMA with the SVC transport switch */
    svc_reg_xprt_class(&svc_rdma_class);
    return 0;
 err1:
    kmem_cache_destroy(svc_rdma_map_cachep);
 err0:
    unregister_sysctl_table(svcrdma_table_header);
    destroy_workqueue(svc_rdma_wq);
    return -ENOMEM;
}
MODULE_AUTHOR("Tom Tucker <[email protected]>");
MODULE_DESCRIPTION("SVC RDMA Transport");
MODULE_LICENSE("Dual BSD/GPL");
module_init(svc_rdma_init);
module_exit(svc_rdma_cleanup);