1 files changed, 266 insertions, 0 deletions
diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c
new file mode 100644
index 000000000000..b1efed546243
--- /dev/null
+++ b/net/smc/smc_sysctl.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  smc_sysctl.c: sysctl interface to SMC subsystem.
+ *
+ *  Copyright (c) 2022, Alibaba Inc.
+ *
+ *  Author: Tony Lu <tonylu@linux.alibaba.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/sysctl.h>
+#include <linux/bpf.h>
+#include <net/net_namespace.h>
+
+#include "smc.h"
+#include "smc_core.h"
+#include "smc_llc.h"
+#include "smc_sysctl.h"
+#include "smc_hs_bpf.h"
+
+static int min_sndbuf = SMC_BUF_MIN_SIZE;
+static int min_rcvbuf = SMC_BUF_MIN_SIZE;
+static int max_sndbuf = INT_MAX / 2;
+static int max_rcvbuf = INT_MAX / 2;
+static const int net_smc_wmem_init = (64 * 1024);
+static const int net_smc_rmem_init = (64 * 1024);
+static int links_per_lgr_min = SMC_LINKS_ADD_LNK_MIN;
+static int links_per_lgr_max = SMC_LINKS_ADD_LNK_MAX;
+static int conns_per_lgr_min = SMC_CONN_PER_LGR_MIN;
+static int conns_per_lgr_max = SMC_CONN_PER_LGR_MAX;
+static unsigned int smcr_max_wr_min = 2;
+static unsigned int smcr_max_wr_max = 2048;
+
+#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
+static int smc_net_replace_smc_hs_ctrl(struct net *net, const char *name)
+{
+	struct smc_hs_ctrl *ctrl = NULL;
+
+	rcu_read_lock();
+	/* null or empty name ask to clear current ctrl */
+	if (name && name[0]) {
+		ctrl = smc_hs_ctrl_find_by_name(name);
+		if (!ctrl) {
+			rcu_read_unlock();
+			return -EINVAL;
+		}
+		/* no change, just return */
+		if (ctrl == rcu_dereference(net->smc.hs_ctrl)) {
+			rcu_read_unlock();
+			return 0;
+		}
+		if (!bpf_try_module_get(ctrl, ctrl->owner)) {
+			rcu_read_unlock();
+			return -EBUSY;
+		}
+	}
+	/* xhcg old ctrl with the new one atomically */
+	ctrl = unrcu_pointer(xchg(&net->smc.hs_ctrl, RCU_INITIALIZER(ctrl)));
+	/* release old ctrl */
+	if (ctrl)
+		bpf_module_put(ctrl, ctrl->owner);
+
+	rcu_read_unlock();
+	return 0;
+}
+
+static int proc_smc_hs_ctrl(const struct ctl_table *ctl, int write,
+			    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct net *net = container_of(ctl->data, struct net, smc.hs_ctrl);
+	char val[SMC_HS_CTRL_NAME_MAX];
+	const struct ctl_table tbl = {
+		.data = val,
+		.maxlen = SMC_HS_CTRL_NAME_MAX,
+	};
+	struct smc_hs_ctrl *ctrl;
+	int ret;
+
+	rcu_read_lock();
+	ctrl = rcu_dereference(net->smc.hs_ctrl);
+	if (ctrl)
+		memcpy(val, ctrl->name, sizeof(ctrl->name));
+	else
+		val[0] = '\0';
+	rcu_read_unlock();
+
+	ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
+
+	if (write)
+		ret = smc_net_replace_smc_hs_ctrl(net, val);
+	return ret;
+}
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
+
+static struct ctl_table smc_table[] = {
+	{
+		.procname       = "autocorking_size",
+		.data           = &init_net.smc.sysctl_autocorking_size,
+		.maxlen         = sizeof(unsigned int),
+		.mode           = 0644,
+		.proc_handler	= proc_douintvec,
+	},
+	{
+		.procname	= "smcr_buf_type",
+		.data		= &init_net.smc.sysctl_smcr_buf_type,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_douintvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_TWO,
+	},
+	{
+		.procname	= "smcr_testlink_time",
+		.data		= &init_net.smc.sysctl_smcr_testlink_time,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{
+		.procname	= "wmem",
+		.data		= &init_net.smc.sysctl_wmem,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &min_sndbuf,
+		.extra2		= &max_sndbuf,
+	},
+	{
+		.procname	= "rmem",
+		.data		= &init_net.smc.sysctl_rmem,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &min_rcvbuf,
+		.extra2		= &max_rcvbuf,
+	},
+	{
+		.procname	= "smcr_max_links_per_lgr",
+		.data		= &init_net.smc.sysctl_max_links_per_lgr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &links_per_lgr_min,
+		.extra2		= &links_per_lgr_max,
+	},
+	{
+		.procname	= "smcr_max_conns_per_lgr",
+		.data		= &init_net.smc.sysctl_max_conns_per_lgr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &conns_per_lgr_min,
+		.extra2		= &conns_per_lgr_max,
+	},
+	{
+		.procname	= "limit_smc_hs",
+		.data		= &init_net.smc.limit_smc_hs,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "smcr_max_send_wr",
+		.data		= &init_net.smc.sysctl_smcr_max_send_wr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &smcr_max_wr_min,
+		.extra2		= &smcr_max_wr_max,
+	},
+	{
+		.procname	= "smcr_max_recv_wr",
+		.data		= &init_net.smc.sysctl_smcr_max_recv_wr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &smcr_max_wr_min,
+		.extra2		= &smcr_max_wr_max,
+	},
+#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
+	{
+		.procname	= "hs_ctrl",
+		.data		= &init_net.smc.hs_ctrl,
+		.mode		= 0644,
+		.maxlen		= SMC_HS_CTRL_NAME_MAX,
+		.proc_handler	= proc_smc_hs_ctrl,
+	},
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
+};
+
+int __net_init smc_sysctl_net_init(struct net *net)
+{
+	size_t table_size = ARRAY_SIZE(smc_table);
+	struct ctl_table *table;
+
+	table = smc_table;
+	if (!net_eq(net, &init_net)) {
+		int i;
+#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
+		struct smc_hs_ctrl *ctrl;
+
+		rcu_read_lock();
+		ctrl = rcu_dereference(init_net.smc.hs_ctrl);
+		if (ctrl && ctrl->flags & SMC_HS_CTRL_FLAG_INHERITABLE &&
+		    bpf_try_module_get(ctrl, ctrl->owner))
+			rcu_assign_pointer(net->smc.hs_ctrl, ctrl);
+		rcu_read_unlock();
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
+
+		table = kmemdup(table, sizeof(smc_table), GFP_KERNEL);
+		if (!table)
+			goto err_alloc;
+
+		for (i = 0; i < table_size; i++)
+			table[i].data += (void *)net - (void *)&init_net;
+	}
+
+	net->smc.smc_hdr = register_net_sysctl_sz(net, "net/smc", table,
+						  table_size);
+	if (!net->smc.smc_hdr)
+		goto err_reg;
+
+	net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
+	net->smc.sysctl_smcr_buf_type = SMCR_PHYS_CONT_BUFS;
+	net->smc.sysctl_smcr_testlink_time = SMC_LLC_TESTLINK_DEFAULT_TIME;
+	WRITE_ONCE(net->smc.sysctl_wmem, net_smc_wmem_init);
+	WRITE_ONCE(net->smc.sysctl_rmem, net_smc_rmem_init);
+	net->smc.sysctl_max_links_per_lgr = SMC_LINKS_PER_LGR_MAX_PREFER;
+	net->smc.sysctl_max_conns_per_lgr = SMC_CONN_PER_LGR_PREFER;
+	net->smc.sysctl_smcr_max_send_wr = SMCR_MAX_SEND_WR_DEF;
+	net->smc.sysctl_smcr_max_recv_wr = SMCR_MAX_RECV_WR_DEF;
+	/* disable handshake limitation by default */
+	net->smc.limit_smc_hs = 0;
+
+	return 0;
+
+err_reg:
+	if (!net_eq(net, &init_net))
+		kfree(table);
+err_alloc:
+#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
+	smc_net_replace_smc_hs_ctrl(net, NULL);
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
+	return -ENOMEM;
+}
+
+void __net_exit smc_sysctl_net_exit(struct net *net)
+{
+	const struct ctl_table *table;
+
+	table = net->smc.smc_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->smc.smc_hdr);
+#if IS_ENABLED(CONFIG_SMC_HS_CTRL_BPF)
+	smc_net_replace_smc_hs_ctrl(net, NULL);
+#endif /* CONFIG_SMC_HS_CTRL_BPF */
+
+	if (!net_eq(net, &init_net))
+		kfree(table);
+}