RDMA/nldev: Add support to get status of all counters

This patch adds the ability to get the name, index and status of all
counters for each link through RDMA netlink. This can be used for
user-space to get the current optional-counter mode.

Examples:
$ rdma statistic mode
link rocep8s0f0/1 optional-counters cc_rx_ce_pkts

$ rdma statistic mode supported
link rocep8s0f0/1 supported optional-counters cc_rx_ce_pkts,cc_rx_cnp_pkts,cc_tx_cnp_pkts
link rocep8s0f1/1 supported optional-counters cc_rx_ce_pkts,cc_rx_cnp_pkts,cc_tx_cnp_pkts

Link: https://lore.kernel.org/r/20211008122439.166063-8-markzhang@nvidia.com
Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Signed-off-by: Neta Ostrovsky <netao@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/nldev.c

@@ -154,6 +154,8 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
 	[RDMA_NLDEV_NET_NS_FD]			= { .type = NLA_U32 },
 	[RDMA_NLDEV_SYS_ATTR_NETNS_MODE]	= { .type = NLA_U8 },
 	[RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK]	= { .type = NLA_U8 },
+	[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_INDEX]	= { .type = NLA_U32 },
+	[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC] = { .type = NLA_U8 },
 };
 
 static int put_driver_name_print_type(struct sk_buff *msg, const char *name,
@@ -2264,6 +2266,99 @@ static int nldev_stat_get_dumpit(struct sk_buff *skb,
 	return ret;
 }
 
+static int nldev_stat_get_counter_status_doit(struct sk_buff *skb,
+					      struct nlmsghdr *nlh,
+					      struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX], *table, *entry;
+	struct rdma_hw_stats *stats;
+	struct ib_device *device;
+	struct sk_buff *msg;
+	u32 devid, port;
+	int ret, i;
+
+	ret = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
+			  nldev_policy, extack);
+	if (ret || !tb[RDMA_NLDEV_ATTR_DEV_INDEX] ||
+	    !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
+		return -EINVAL;
+
+	devid = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
+	device = ib_device_get_by_index(sock_net(skb->sk), devid);
+	if (!device)
+		return -EINVAL;
+
+	port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
+	if (!rdma_is_port_valid(device, port)) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	stats = ib_get_hw_stats_port(device, port);
+	if (!stats) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	nlh = nlmsg_put(
+		msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
+		RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_STAT_GET_STATUS),
+		0, 0);
+
+	ret = -EMSGSIZE;
+	if (fill_nldev_handle(msg, device) ||
+	    nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, port))
+		goto err_msg;
+
+	table = nla_nest_start(msg, RDMA_NLDEV_ATTR_STAT_HWCOUNTERS);
+	if (!table)
+		goto err_msg;
+
+	mutex_lock(&stats->lock);
+	for (i = 0; i < stats->num_counters; i++) {
+		entry = nla_nest_start(msg,
+				       RDMA_NLDEV_ATTR_STAT_HWCOUNTER_ENTRY);
+		if (!entry)
+			goto err_msg_table;
+
+		if (nla_put_string(msg,
+				   RDMA_NLDEV_ATTR_STAT_HWCOUNTER_ENTRY_NAME,
+				   stats->descs[i].name) ||
+		    nla_put_u32(msg, RDMA_NLDEV_ATTR_STAT_HWCOUNTER_INDEX, i))
+			goto err_msg_entry;
+
+		if ((stats->descs[i].flags & IB_STAT_FLAG_OPTIONAL) &&
+		    (nla_put_u8(msg, RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC,
+				!test_bit(i, stats->is_disabled))))
+			goto err_msg_entry;
+
+		nla_nest_end(msg, entry);
+	}
+	mutex_unlock(&stats->lock);
+
+	nla_nest_end(msg, table);
+	nlmsg_end(msg, nlh);
+	ib_device_put(device);
+	return rdma_nl_unicast(sock_net(skb->sk), msg, NETLINK_CB(skb).portid);
+
+err_msg_entry:
+	nla_nest_cancel(msg, entry);
+err_msg_table:
+	mutex_unlock(&stats->lock);
+	nla_nest_cancel(msg, table);
+err_msg:
+	nlmsg_free(msg);
+err:
+	ib_device_put(device);
+	return ret;
+}
+
 static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
 	[RDMA_NLDEV_CMD_GET] = {
 		.doit = nldev_get_doit,
@@ -2353,6 +2448,9 @@ static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
 		.dump = nldev_res_get_mr_raw_dumpit,
 		.flags = RDMA_NL_ADMIN_PERM,
 	},
+	[RDMA_NLDEV_CMD_STAT_GET_STATUS] = {
+		.doit = nldev_stat_get_counter_status_doit,
+	},
 };
 
 void __init nldev_init(void)

include/uapi/rdma/rdma_netlink.h

@@ -297,6 +297,8 @@ enum rdma_nldev_command {
 
 	RDMA_NLDEV_CMD_RES_SRQ_GET, /* can dump */
 
+	RDMA_NLDEV_CMD_STAT_GET_STATUS,
+
 	RDMA_NLDEV_NUM_OPS
 };
 
@@ -549,6 +551,9 @@ enum rdma_nldev_attr {
 
 	RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK,	/* u8 */
 
+	RDMA_NLDEV_ATTR_STAT_HWCOUNTER_INDEX,	/* u32 */
+	RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC, /* u8 */
+
 	/*
 	 * Always the end
 	 */