root/net/sunrpc/xprtrdma/svc_rdma.c

DEFINITIONS

1. read_reset_stat
2. svc_rdma_cleanup
3. svc_rdma_init

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright (c) 2015-2018 Oracle.  All rights reserved.
   4  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the BSD-type
  10  * license below:
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  *
  16  *      Redistributions of source code must retain the above copyright
  17  *      notice, this list of conditions and the following disclaimer.
  18  *
  19  *      Redistributions in binary form must reproduce the above
  20  *      copyright notice, this list of conditions and the following
  21  *      disclaimer in the documentation and/or other materials provided
  22  *      with the distribution.
  23  *
  24  *      Neither the name of the Network Appliance, Inc. nor the names of
  25  *      its contributors may be used to endorse or promote products
  26  *      derived from this software without specific prior written
  27  *      permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  30  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  32  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  33  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  34  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  35  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  *
  41  * Author: Tom Tucker <tom@opengridcomputing.com>
  42  */
  43 
  44 #include <linux/slab.h>
  45 #include <linux/fs.h>
  46 #include <linux/sysctl.h>
  47 #include <linux/workqueue.h>
  48 #include <linux/sunrpc/clnt.h>
  49 #include <linux/sunrpc/sched.h>
  50 #include <linux/sunrpc/svc_rdma.h>
  51 
  52 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
  53 
  54 /* RPC/RDMA parameters */
  55 unsigned int svcrdma_ord = 16;  /* historical default */
  56 static unsigned int min_ord = 1;
  57 static unsigned int max_ord = 255;
  58 unsigned int svcrdma_max_requests = RPCRDMA_MAX_REQUESTS;
  59 unsigned int svcrdma_max_bc_requests = RPCRDMA_MAX_BC_REQUESTS;
  60 static unsigned int min_max_requests = 4;
  61 static unsigned int max_max_requests = 16384;
  62 unsigned int svcrdma_max_req_size = RPCRDMA_DEF_INLINE_THRESH;
  63 static unsigned int min_max_inline = RPCRDMA_DEF_INLINE_THRESH;
  64 static unsigned int max_max_inline = RPCRDMA_MAX_INLINE_THRESH;
  65 
  66 atomic_t rdma_stat_recv;
  67 atomic_t rdma_stat_read;
  68 atomic_t rdma_stat_write;
  69 atomic_t rdma_stat_sq_starve;
  70 atomic_t rdma_stat_rq_starve;
  71 atomic_t rdma_stat_rq_poll;
  72 atomic_t rdma_stat_rq_prod;
  73 atomic_t rdma_stat_sq_poll;
  74 atomic_t rdma_stat_sq_prod;
  75 
  76 /*
  77  * This function implements reading and resetting an atomic_t stat
  78  * variable through read/write to a proc file. Any write to the file
  79  * resets the associated statistic to zero. Any read returns it's
  80  * current value.
  81  */
  82 static int read_reset_stat(struct ctl_table *table, int write,
  83                            void __user *buffer, size_t *lenp,
  84                            loff_t *ppos)
  85 {
  86         atomic_t *stat = (atomic_t *)table->data;
  87 
  88         if (!stat)
  89                 return -EINVAL;
  90 
  91         if (write)
  92                 atomic_set(stat, 0);
  93         else {
  94                 char str_buf[32];
  95                 int len = snprintf(str_buf, 32, "%d\n", atomic_read(stat));
  96                 if (len >= 32)
  97                         return -EFAULT;
  98                 len = strlen(str_buf);
  99                 if (*ppos > len) {
 100                         *lenp = 0;
 101                         return 0;
 102                 }
 103                 len -= *ppos;
 104                 if (len > *lenp)
 105                         len = *lenp;
 106                 if (len && copy_to_user(buffer, str_buf, len))
 107                         return -EFAULT;
 108                 *lenp = len;
 109                 *ppos += len;
 110         }
 111         return 0;
 112 }
 113 
 114 static struct ctl_table_header *svcrdma_table_header;
 115 static struct ctl_table svcrdma_parm_table[] = {
 116         {
 117                 .procname       = "max_requests",
 118                 .data           = &svcrdma_max_requests,
 119                 .maxlen         = sizeof(unsigned int),
 120                 .mode           = 0644,
 121                 .proc_handler   = proc_dointvec_minmax,
 122                 .extra1         = &min_max_requests,
 123                 .extra2         = &max_max_requests
 124         },
 125         {
 126                 .procname       = "max_req_size",
 127                 .data           = &svcrdma_max_req_size,
 128                 .maxlen         = sizeof(unsigned int),
 129                 .mode           = 0644,
 130                 .proc_handler   = proc_dointvec_minmax,
 131                 .extra1         = &min_max_inline,
 132                 .extra2         = &max_max_inline
 133         },
 134         {
 135                 .procname       = "max_outbound_read_requests",
 136                 .data           = &svcrdma_ord,
 137                 .maxlen         = sizeof(unsigned int),
 138                 .mode           = 0644,
 139                 .proc_handler   = proc_dointvec_minmax,
 140                 .extra1         = &min_ord,
 141                 .extra2         = &max_ord,
 142         },
 143 
 144         {
 145                 .procname       = "rdma_stat_read",
 146                 .data           = &rdma_stat_read,
 147                 .maxlen         = sizeof(atomic_t),
 148                 .mode           = 0644,
 149                 .proc_handler   = read_reset_stat,
 150         },
 151         {
 152                 .procname       = "rdma_stat_recv",
 153                 .data           = &rdma_stat_recv,
 154                 .maxlen         = sizeof(atomic_t),
 155                 .mode           = 0644,
 156                 .proc_handler   = read_reset_stat,
 157         },
 158         {
 159                 .procname       = "rdma_stat_write",
 160                 .data           = &rdma_stat_write,
 161                 .maxlen         = sizeof(atomic_t),
 162                 .mode           = 0644,
 163                 .proc_handler   = read_reset_stat,
 164         },
 165         {
 166                 .procname       = "rdma_stat_sq_starve",
 167                 .data           = &rdma_stat_sq_starve,
 168                 .maxlen         = sizeof(atomic_t),
 169                 .mode           = 0644,
 170                 .proc_handler   = read_reset_stat,
 171         },
 172         {
 173                 .procname       = "rdma_stat_rq_starve",
 174                 .data           = &rdma_stat_rq_starve,
 175                 .maxlen         = sizeof(atomic_t),
 176                 .mode           = 0644,
 177                 .proc_handler   = read_reset_stat,
 178         },
 179         {
 180                 .procname       = "rdma_stat_rq_poll",
 181                 .data           = &rdma_stat_rq_poll,
 182                 .maxlen         = sizeof(atomic_t),
 183                 .mode           = 0644,
 184                 .proc_handler   = read_reset_stat,
 185         },
 186         {
 187                 .procname       = "rdma_stat_rq_prod",
 188                 .data           = &rdma_stat_rq_prod,
 189                 .maxlen         = sizeof(atomic_t),
 190                 .mode           = 0644,
 191                 .proc_handler   = read_reset_stat,
 192         },
 193         {
 194                 .procname       = "rdma_stat_sq_poll",
 195                 .data           = &rdma_stat_sq_poll,
 196                 .maxlen         = sizeof(atomic_t),
 197                 .mode           = 0644,
 198                 .proc_handler   = read_reset_stat,
 199         },
 200         {
 201                 .procname       = "rdma_stat_sq_prod",
 202                 .data           = &rdma_stat_sq_prod,
 203                 .maxlen         = sizeof(atomic_t),
 204                 .mode           = 0644,
 205                 .proc_handler   = read_reset_stat,
 206         },
 207         { },
 208 };
 209 
 210 static struct ctl_table svcrdma_table[] = {
 211         {
 212                 .procname       = "svc_rdma",
 213                 .mode           = 0555,
 214                 .child          = svcrdma_parm_table
 215         },
 216         { },
 217 };
 218 
 219 static struct ctl_table svcrdma_root_table[] = {
 220         {
 221                 .procname       = "sunrpc",
 222                 .mode           = 0555,
 223                 .child          = svcrdma_table
 224         },
 225         { },
 226 };
 227 
 228 void svc_rdma_cleanup(void)
 229 {
 230         dprintk("SVCRDMA Module Removed, deregister RPC RDMA transport\n");
 231         if (svcrdma_table_header) {
 232                 unregister_sysctl_table(svcrdma_table_header);
 233                 svcrdma_table_header = NULL;
 234         }
 235         svc_unreg_xprt_class(&svc_rdma_class);
 236 }
 237 
 238 int svc_rdma_init(void)
 239 {
 240         dprintk("SVCRDMA Module Init, register RPC RDMA transport\n");
 241         dprintk("\tsvcrdma_ord      : %d\n", svcrdma_ord);
 242         dprintk("\tmax_requests     : %u\n", svcrdma_max_requests);
 243         dprintk("\tmax_bc_requests  : %u\n", svcrdma_max_bc_requests);
 244         dprintk("\tmax_inline       : %d\n", svcrdma_max_req_size);
 245 
 246         if (!svcrdma_table_header)
 247                 svcrdma_table_header =
 248                         register_sysctl_table(svcrdma_root_table);
 249 
 250         /* Register RDMA with the SVC transport switch */
 251         svc_reg_xprt_class(&svc_rdma_class);
 252         return 0;
 253 }