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                 char *data;
  98                 int len = snprintf(str_buf, 32, "%d\n", atomic_read(stat));
  99                 if (len >= 32)
 100                         return -EFAULT;
 101                 len = strlen(str_buf);
 102                 if (*ppos > len) {
 103                         *lenp = 0;
 104                         return 0;
 105                 }
 106                 data = &str_buf[*ppos];
 107                 len -= *ppos;
 108                 if (len > *lenp)
 109                         len = *lenp;
 110                 if (len && copy_to_user(buffer, str_buf, len))
 111                         return -EFAULT;
 112                 *lenp = len;
 113                 *ppos += len;
 114         }
 115         return 0;
 116 }
 117
 118 static struct ctl_table_header *svcrdma_table_header;
 119 static struct ctl_table svcrdma_parm_table[] = {
 120         {
 121                 .procname       = "max_requests",
 122                 .data           = &svcrdma_max_requests,
 123                 .maxlen         = sizeof(unsigned int),
 124                 .mode           = 0644,
 125                 .proc_handler   = proc_dointvec_minmax,
 126                 .extra1         = &min_max_requests,
 127                 .extra2         = &max_max_requests
 128         },
 129         {
 130                 .procname       = "max_req_size",
 131                 .data           = &svcrdma_max_req_size,
 132                 .maxlen         = sizeof(unsigned int),
 133                 .mode           = 0644,
 134                 .proc_handler   = proc_dointvec_minmax,
 135                 .extra1         = &min_max_inline,
 136                 .extra2         = &max_max_inline
 137         },
 138         {
 139                 .procname       = "max_outbound_read_requests",
 140                 .data           = &svcrdma_ord,
 141                 .maxlen         = sizeof(unsigned int),
 142                 .mode           = 0644,
 143                 .proc_handler   = proc_dointvec_minmax,
 144                 .extra1         = &min_ord,
 145                 .extra2         = &max_ord,
 146         },
 147
 148         {
 149                 .procname       = "rdma_stat_read",
 150                 .data           = &rdma_stat_read,
 151                 .maxlen         = sizeof(atomic_t),
 152                 .mode           = 0644,
 153                 .proc_handler   = read_reset_stat,
 154         },
 155         {
 156                 .procname       = "rdma_stat_recv",
 157                 .data           = &rdma_stat_recv,
 158                 .maxlen         = sizeof(atomic_t),
 159                 .mode           = 0644,
 160                 .proc_handler   = read_reset_stat,
 161         },
 162         {
 163                 .procname       = "rdma_stat_write",
 164                 .data           = &rdma_stat_write,
 165                 .maxlen         = sizeof(atomic_t),
 166                 .mode           = 0644,
 167                 .proc_handler   = read_reset_stat,
 168         },
 169         {
 170                 .procname       = "rdma_stat_sq_starve",
 171                 .data           = &rdma_stat_sq_starve,
 172                 .maxlen         = sizeof(atomic_t),
 173                 .mode           = 0644,
 174                 .proc_handler   = read_reset_stat,
 175         },
 176         {
 177                 .procname       = "rdma_stat_rq_starve",
 178                 .data           = &rdma_stat_rq_starve,
 179                 .maxlen         = sizeof(atomic_t),
 180                 .mode           = 0644,
 181                 .proc_handler   = read_reset_stat,
 182         },
 183         {
 184                 .procname       = "rdma_stat_rq_poll",
 185                 .data           = &rdma_stat_rq_poll,
 186                 .maxlen         = sizeof(atomic_t),
 187                 .mode           = 0644,
 188                 .proc_handler   = read_reset_stat,
 189         },
 190         {
 191                 .procname       = "rdma_stat_rq_prod",
 192                 .data           = &rdma_stat_rq_prod,
 193                 .maxlen         = sizeof(atomic_t),
 194                 .mode           = 0644,
 195                 .proc_handler   = read_reset_stat,
 196         },
 197         {
 198                 .procname       = "rdma_stat_sq_poll",
 199                 .data           = &rdma_stat_sq_poll,
 200                 .maxlen         = sizeof(atomic_t),
 201                 .mode           = 0644,
 202                 .proc_handler   = read_reset_stat,
 203         },
 204         {
 205                 .procname       = "rdma_stat_sq_prod",
 206                 .data           = &rdma_stat_sq_prod,
 207                 .maxlen         = sizeof(atomic_t),
 208                 .mode           = 0644,
 209                 .proc_handler   = read_reset_stat,
 210         },
 211         { },
 212 };
 213
 214 static struct ctl_table svcrdma_table[] = {
 215         {
 216                 .procname       = "svc_rdma",
 217                 .mode           = 0555,
 218                 .child          = svcrdma_parm_table
 219         },
 220         { },
 221 };
 222
 223 static struct ctl_table svcrdma_root_table[] = {
 224         {
 225                 .procname       = "sunrpc",
 226                 .mode           = 0555,
 227                 .child          = svcrdma_table
 228         },
 229         { },
 230 };
 231
 232 void svc_rdma_cleanup(void)
 233 {
 234         dprintk("SVCRDMA Module Removed, deregister RPC RDMA transport\n");
 235         destroy_workqueue(svc_rdma_wq);
 236         if (svcrdma_table_header) {
 237                 unregister_sysctl_table(svcrdma_table_header);
 238                 svcrdma_table_header = NULL;
 239         }
 240 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 241         svc_unreg_xprt_class(&svc_rdma_bc_class);
 242 #endif
 243         svc_unreg_xprt_class(&svc_rdma_class);
 244 }
 245
 246 int svc_rdma_init(void)
 247 {
 248         dprintk("SVCRDMA Module Init, register RPC RDMA transport\n");
 249         dprintk("\tsvcrdma_ord      : %d\n", svcrdma_ord);
 250         dprintk("\tmax_requests     : %u\n", svcrdma_max_requests);
 251         dprintk("\tmax_bc_requests  : %u\n", svcrdma_max_bc_requests);
 252         dprintk("\tmax_inline       : %d\n", svcrdma_max_req_size);
 253
 254         svc_rdma_wq = alloc_workqueue("svc_rdma", 0, 0);
 255         if (!svc_rdma_wq)
 256                 return -ENOMEM;
 257
 258         if (!svcrdma_table_header)
 259                 svcrdma_table_header =
 260                         register_sysctl_table(svcrdma_root_table);
 261
 262         /* Register RDMA with the SVC transport switch */
 263         svc_reg_xprt_class(&svc_rdma_class);
 264 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 265         svc_reg_xprt_class(&svc_rdma_bc_class);
 266 #endif
 267         return 0;
 268 }