docs: cgroup-v2: fix misc.events key format descriptiongrafted

In misc cgroup, misc.events does not output a simple "max" key. Instead,
each registered misc resource outputs a separate key suffixed with ".max"
(i.e., "<res>.max").
Update the documentation to clarify that the entry key is "<res>.max".

Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Cheng Lingfei <chenglingfei@foxmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/tools/lib/thermal/sampling.c b/tools/lib/thermal/sampling.c
new file mode 100644
index 000000000..f67c1f9ea
--- /dev/null
+++ b/tools/lib/thermal/sampling.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: LGPL-2.1+
+// Copyright (C) 2022, Linaro Ltd - Daniel Lezcano <daniel.lezcano@linaro.org>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <thermal.h>
+#include "thermal_nl.h"
+
+static int handle_thermal_sample(struct nl_msg *n, void *arg)
+{
+	struct nlmsghdr *nlh = nlmsg_hdr(n);
+	struct genlmsghdr *genlhdr = genlmsg_hdr(nlh);
+	struct nlattr *attrs[THERMAL_GENL_ATTR_MAX + 1];
+	struct thermal_handler_param *thp = arg;
+	struct thermal_handler *th = thp->th;
+
+	arg = thp->arg;
+
+	genlmsg_parse(nlh, 0, attrs, THERMAL_GENL_ATTR_MAX, NULL);
+
+	switch (genlhdr->cmd) {
+
+	case THERMAL_GENL_SAMPLING_TEMP:
+		return th->ops->sampling.tz_temp(
+			nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_ID]),
+			nla_get_u32(attrs[THERMAL_GENL_ATTR_TZ_TEMP]), arg);
+	default:
+		return THERMAL_ERROR;
+	}
+}
+
+thermal_error_t thermal_sampling_handle(struct thermal_handler *th, void *arg)
+{
+	struct thermal_handler_param thp = { .th = th, .arg = arg };
+
+	if (!th)
+		return THERMAL_ERROR;
+
+	if (nl_cb_set(th->cb_sampling, NL_CB_VALID, NL_CB_CUSTOM,
+		      handle_thermal_sample, &thp))
+		return THERMAL_ERROR;
+
+	return nl_recvmsgs(th->sk_sampling, th->cb_sampling);
+}
+
+int thermal_sampling_fd(struct thermal_handler *th)
+{
+	if (!th)
+		return -1;
+
+	return nl_socket_get_fd(th->sk_sampling);
+}
+
+thermal_error_t thermal_sampling_exit(struct thermal_handler *th)
+{
+	if (nl_unsubscribe_thermal(th->sk_sampling, th->cb_sampling,
+				   THERMAL_GENL_SAMPLING_GROUP_NAME))
+		return THERMAL_ERROR;
+
+	nl_thermal_disconnect(th->sk_sampling, th->cb_sampling);
+
+	return THERMAL_SUCCESS;
+}
+
+thermal_error_t thermal_sampling_init(struct thermal_handler *th)
+{
+	if (nl_thermal_connect(&th->sk_sampling, &th->cb_sampling))
+		return THERMAL_ERROR;
+
+	if (nl_subscribe_thermal(th->sk_sampling, th->cb_sampling,
+				 THERMAL_GENL_SAMPLING_GROUP_NAME))
+		return THERMAL_ERROR;
+
+	return THERMAL_SUCCESS;
+}