1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
  4 *
  5 *  smc_sysctl.c: sysctl interface to SMC subsystem.
  6 *
  7 *  Copyright (c) 2022, Alibaba Inc.
  8 *
  9 *  Author: Tony Lu <tonylu@linux.alibaba.com>
 10 *
 11 */
 12
 13#include <linux/init.h>
 14#include <linux/sysctl.h>
 15#include <net/net_namespace.h>
 16
 17#include "smc.h"
 18#include "smc_core.h"
 19#include "smc_llc.h"
 20#include "smc_sysctl.h"
 21
 22static int min_sndbuf = SMC_BUF_MIN_SIZE;
 23static int min_rcvbuf = SMC_BUF_MIN_SIZE;
 24static int max_sndbuf = INT_MAX / 2;
 25static int max_rcvbuf = INT_MAX / 2;
 26static const int net_smc_wmem_init = (64 * 1024);
 27static const int net_smc_rmem_init = (64 * 1024);
 28static int links_per_lgr_min = SMC_LINKS_ADD_LNK_MIN;
 29static int links_per_lgr_max = SMC_LINKS_ADD_LNK_MAX;
 30static int conns_per_lgr_min = SMC_CONN_PER_LGR_MIN;
 31static int conns_per_lgr_max = SMC_CONN_PER_LGR_MAX;
 32
 33static struct ctl_table smc_table[] = {
 34	{
 35		.procname       = "autocorking_size",
 36		.data           = &init_net.smc.sysctl_autocorking_size,
 37		.maxlen         = sizeof(unsigned int),
 38		.mode           = 0644,
 39		.proc_handler	= proc_douintvec,
 40	},
 41	{
 42		.procname	= "smcr_buf_type",
 43		.data		= &init_net.smc.sysctl_smcr_buf_type,
 44		.maxlen		= sizeof(unsigned int),
 45		.mode		= 0644,
 46		.proc_handler	= proc_douintvec_minmax,
 47		.extra1		= SYSCTL_ZERO,
 48		.extra2		= SYSCTL_TWO,
 49	},
 50	{
 51		.procname	= "smcr_testlink_time",
 52		.data		= &init_net.smc.sysctl_smcr_testlink_time,
 53		.maxlen		= sizeof(int),
 54		.mode		= 0644,
 55		.proc_handler	= proc_dointvec_jiffies,
 56	},
 57	{
 58		.procname	= "wmem",
 59		.data		= &init_net.smc.sysctl_wmem,
 60		.maxlen		= sizeof(int),
 61		.mode		= 0644,
 62		.proc_handler	= proc_dointvec_minmax,
 63		.extra1		= &min_sndbuf,
 64		.extra2		= &max_sndbuf,
 65	},
 66	{
 67		.procname	= "rmem",
 68		.data		= &init_net.smc.sysctl_rmem,
 69		.maxlen		= sizeof(int),
 70		.mode		= 0644,
 71		.proc_handler	= proc_dointvec_minmax,
 72		.extra1		= &min_rcvbuf,
 73		.extra2		= &max_rcvbuf,
 74	},
 75	{
 76		.procname	= "smcr_max_links_per_lgr",
 77		.data		= &init_net.smc.sysctl_max_links_per_lgr,
 78		.maxlen		= sizeof(int),
 79		.mode		= 0644,
 80		.proc_handler	= proc_dointvec_minmax,
 81		.extra1		= &links_per_lgr_min,
 82		.extra2		= &links_per_lgr_max,
 83	},
 84	{
 85		.procname	= "smcr_max_conns_per_lgr",
 86		.data		= &init_net.smc.sysctl_max_conns_per_lgr,
 87		.maxlen		= sizeof(int),
 88		.mode		= 0644,
 89		.proc_handler	= proc_dointvec_minmax,
 90		.extra1		= &conns_per_lgr_min,
 91		.extra2		= &conns_per_lgr_max,
 92	},
 93	{  }
 94};
 95
 96int __net_init smc_sysctl_net_init(struct net *net)
 97{
 98	struct ctl_table *table;
 99
100	table = smc_table;
101	if (!net_eq(net, &init_net)) {
102		int i;
103
104		table = kmemdup(table, sizeof(smc_table), GFP_KERNEL);
105		if (!table)
106			goto err_alloc;
107
108		for (i = 0; i < ARRAY_SIZE(smc_table) - 1; i++)
109			table[i].data += (void *)net - (void *)&init_net;
110	}
111
112	net->smc.smc_hdr = register_net_sysctl_sz(net, "net/smc", table,
113						  ARRAY_SIZE(smc_table));
114	if (!net->smc.smc_hdr)
115		goto err_reg;
116
117	net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
118	net->smc.sysctl_smcr_buf_type = SMCR_PHYS_CONT_BUFS;
119	net->smc.sysctl_smcr_testlink_time = SMC_LLC_TESTLINK_DEFAULT_TIME;
120	WRITE_ONCE(net->smc.sysctl_wmem, net_smc_wmem_init);
121	WRITE_ONCE(net->smc.sysctl_rmem, net_smc_rmem_init);
122	net->smc.sysctl_max_links_per_lgr = SMC_LINKS_PER_LGR_MAX_PREFER;
123	net->smc.sysctl_max_conns_per_lgr = SMC_CONN_PER_LGR_PREFER;
124
125	return 0;
126
127err_reg:
128	if (!net_eq(net, &init_net))
129		kfree(table);
130err_alloc:
131	return -ENOMEM;
132}
133
134void __net_exit smc_sysctl_net_exit(struct net *net)
135{
136	struct ctl_table *table;
137
138	table = net->smc.smc_hdr->ctl_table_arg;
139	unregister_net_sysctl_table(net->smc.smc_hdr);
140	if (!net_eq(net, &init_net))
141		kfree(table);
142}