net/sunrpc/xprtrdma/svc_rdma.c

   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 struct workqueue_struct *svc_rdma_wq;
  77
  78 /*
  79  * This function implements reading and resetting an atomic_t stat
  80  * variable through read/write to a proc file. Any write to the file
  81  * resets the associated statistic to zero. Any read returns it's
  82  * current value.
  83  */
  84 static int read_reset_stat(struct ctl_table *table, int write,
  85                            void __user *buffer, size_t *lenp,
  86                            loff_t *ppos)
  87 {
  88         atomic_t *stat = (atomic_t *)table->data;
  89
  90         if (!stat)
  91                 return -EINVAL;
  92
  93         if (write)
  94                 atomic_set(stat, 0);
  95         else {
  96                 char str_buf[32];
  97                 int len = snprintf(str_buf, 32, "%d\n", atomic_read(stat));
  98                 if (len >= 32)
  99                         return -EFAULT;
 100                 len = strlen(str_buf);
 101                 if (*ppos > len) {
 102                         *lenp = 0;
 103                         return 0;
 104                 }
 105                 len -= *ppos;
 106                 if (len > *lenp)
 107                         len = *lenp;
 108                 if (len && copy_to_user(buffer, str_buf, len))
 109                         return -EFAULT;
 110                 *lenp = len;
 111                 *ppos += len;
 112         }
 113         return 0;
 114 }
 115
 116 static struct ctl_table_header *svcrdma_table_header;
 117 static struct ctl_table svcrdma_parm_table[] = {
 118         {
 119                 .procname       = "max_requests",
 120                 .data           = &svcrdma_max_requests,
 121                 .maxlen         = sizeof(unsigned int),
 122                 .mode           = 0644,
 123                 .proc_handler   = proc_dointvec_minmax,
 124                 .extra1         = &min_max_requests,
 125                 .extra2         = &max_max_requests
 126         },
 127         {
 128                 .procname       = "max_req_size",
 129                 .data           = &svcrdma_max_req_size,
 130                 .maxlen         = sizeof(unsigned int),
 131                 .mode           = 0644,
 132                 .proc_handler   = proc_dointvec_minmax,
 133                 .extra1         = &min_max_inline,
 134                 .extra2         = &max_max_inline
 135         },
 136         {
 137                 .procname       = "max_outbound_read_requests",
 138                 .data           = &svcrdma_ord,
 139                 .maxlen         = sizeof(unsigned int),
 140                 .mode           = 0644,
 141                 .proc_handler   = proc_dointvec_minmax,
 142                 .extra1         = &min_ord,
 143                 .extra2         = &max_ord,
 144         },
 145
 146         {
 147                 .procname       = "rdma_stat_read",
 148                 .data           = &rdma_stat_read,
 149                 .maxlen         = sizeof(atomic_t),
 150                 .mode           = 0644,
 151                 .proc_handler   = read_reset_stat,
 152         },
 153         {
 154                 .procname       = "rdma_stat_recv",
 155                 .data           = &rdma_stat_recv,
 156                 .maxlen         = sizeof(atomic_t),
 157                 .mode           = 0644,
 158                 .proc_handler   = read_reset_stat,
 159         },
 160         {
 161                 .procname       = "rdma_stat_write",
 162                 .data           = &rdma_stat_write,
 163                 .maxlen         = sizeof(atomic_t),
 164                 .mode           = 0644,
 165                 .proc_handler   = read_reset_stat,
 166         },
 167         {
 168                 .procname       = "rdma_stat_sq_starve",
 169                 .data           = &rdma_stat_sq_starve,
 170                 .maxlen         = sizeof(atomic_t),
 171                 .mode           = 0644,
 172                 .proc_handler   = read_reset_stat,
 173         },
 174         {
 175                 .procname       = "rdma_stat_rq_starve",
 176                 .data           = &rdma_stat_rq_starve,
 177                 .maxlen         = sizeof(atomic_t),
 178                 .mode           = 0644,
 179                 .proc_handler   = read_reset_stat,
 180         },
 181         {
 182                 .procname       = "rdma_stat_rq_poll",
 183                 .data           = &rdma_stat_rq_poll,
 184                 .maxlen         = sizeof(atomic_t),
 185                 .mode           = 0644,
 186                 .proc_handler   = read_reset_stat,
 187         },
 188         {
 189                 .procname       = "rdma_stat_rq_prod",
 190                 .data           = &rdma_stat_rq_prod,
 191                 .maxlen         = sizeof(atomic_t),
 192                 .mode           = 0644,
 193                 .proc_handler   = read_reset_stat,
 194         },
 195         {
 196                 .procname       = "rdma_stat_sq_poll",
 197                 .data           = &rdma_stat_sq_poll,
 198                 .maxlen         = sizeof(atomic_t),
 199                 .mode           = 0644,
 200                 .proc_handler   = read_reset_stat,
 201         },
 202         {
 203                 .procname       = "rdma_stat_sq_prod",
 204                 .data           = &rdma_stat_sq_prod,
 205                 .maxlen         = sizeof(atomic_t),
 206                 .mode           = 0644,
 207                 .proc_handler   = read_reset_stat,
 208         },
 209         { },
 210 };
 211
 212 static struct ctl_table svcrdma_table[] = {
 213         {
 214                 .procname       = "svc_rdma",
 215                 .mode           = 0555,
 216                 .child          = svcrdma_parm_table
 217         },
 218         { },
 219 };
 220
 221 static struct ctl_table svcrdma_root_table[] = {
 222         {
 223                 .procname       = "sunrpc",
 224                 .mode           = 0555,
 225                 .child          = svcrdma_table
 226         },
 227         { },
 228 };
 229
 230 void svc_rdma_cleanup(void)
 231 {
 232         dprintk("SVCRDMA Module Removed, deregister RPC RDMA transport\n");
 233         destroy_workqueue(svc_rdma_wq);
 234         if (svcrdma_table_header) {
 235                 unregister_sysctl_table(svcrdma_table_header);
 236                 svcrdma_table_header = NULL;
 237         }
 238 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 239         svc_unreg_xprt_class(&svc_rdma_bc_class);
 240 #endif
 241         svc_unreg_xprt_class(&svc_rdma_class);
 242 }
 243
 244 int svc_rdma_init(void)
 245 {
 246         dprintk("SVCRDMA Module Init, register RPC RDMA transport\n");
 247         dprintk("\tsvcrdma_ord      : %d\n", svcrdma_ord);
 248         dprintk("\tmax_requests     : %u\n", svcrdma_max_requests);
 249         dprintk("\tmax_bc_requests  : %u\n", svcrdma_max_bc_requests);
 250         dprintk("\tmax_inline       : %d\n", svcrdma_max_req_size);
 251
 252         svc_rdma_wq = alloc_workqueue("svc_rdma", 0, 0);
 253         if (!svc_rdma_wq)
 254                 return -ENOMEM;
 255
 256         if (!svcrdma_table_header)
 257                 svcrdma_table_header =
 258                         register_sysctl_table(svcrdma_root_table);
 259
 260         /* Register RDMA with the SVC transport switch */
 261         svc_reg_xprt_class(&svc_rdma_class);
 262 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 263         svc_reg_xprt_class(&svc_rdma_bc_class);
 264 #endif
 265         return 0;
 266 }