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authorJoel Fernandes <joelagnelf@nvidia.com>2026-07-18 13:15:36 -0400
committerPaul E. McKenney <paulmck@kernel.org>2026-07-23 10:39:57 -0700
commit34ff636f322c6d5e4f0a52338fa63a7dff09a495 (patch)
tree7629759c1ec7148b95bc8ab3080df20a5ecd2273 /drivers/rtc/sysfs.c
downloadlinux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.tar.gz
linux-stable-34ff636f322c6d5e4f0a52338fa63a7dff09a495.zip
scftorture: Count single_rpc offline failures in statistics outputgrafted
scf_torture_stats_print() aggregates each invoker thread's counters into a local scf_statistics structure before printing, but the n_single_rpc_ofl field is missing from the aggregation loop. As a result, the "single_rpc_ofl" value printed in the statistics line is always zero, even when smp_call_function_single() invocations for the RPC test have failed due to offline CPUs and been counted by the invoker threads. Add the missing accumulation so that the printed value reflects the actual counts. Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'drivers/rtc/sysfs.c')
-rw-r--r--drivers/rtc/sysfs.c351
1 files changed, 351 insertions, 0 deletions
diff --git a/drivers/rtc/sysfs.c b/drivers/rtc/sysfs.c
new file mode 100644
index 000000000..4ab05e105
--- /dev/null
+++ b/drivers/rtc/sysfs.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RTC subsystem, sysfs interface
+ *
+ * Copyright (C) 2005 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ */
+
+#include <linux/kstrtox.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+#include "rtc-core.h"
+
+/* device attributes */
+
+/*
+ * NOTE: RTC times displayed in sysfs use the RTC's timezone. That's
+ * ideally UTC. However, PCs that also boot to MS-Windows normally use
+ * the local time and change to match daylight savings time. That affects
+ * attributes including date, time, since_epoch, and wakealarm.
+ */
+
+static ssize_t
+name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%s %s\n", dev_driver_string(dev->parent),
+ dev_name(dev->parent));
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t
+date_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return retval;
+
+ return sysfs_emit(buf, "%ptRd\n", &tm);
+}
+static DEVICE_ATTR_RO(date);
+
+static ssize_t
+time_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return retval;
+
+ return sysfs_emit(buf, "%ptRt\n", &tm);
+}
+static DEVICE_ATTR_RO(time);
+
+static ssize_t
+since_epoch_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct rtc_time tm;
+
+ retval = rtc_read_time(to_rtc_device(dev), &tm);
+ if (retval)
+ return retval;
+
+ return sysfs_emit(buf, "%lld\n", rtc_tm_to_time64(&tm));
+}
+static DEVICE_ATTR_RO(since_epoch);
+
+static ssize_t
+max_user_freq_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%d\n", to_rtc_device(dev)->max_user_freq);
+}
+
+static ssize_t
+max_user_freq_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t n)
+{
+ struct rtc_device *rtc = to_rtc_device(dev);
+ unsigned long val;
+ int err;
+
+ err = kstrtoul(buf, 0, &val);
+ if (err)
+ return err;
+
+ if (val >= 4096 || val == 0)
+ return -EINVAL;
+
+ rtc->max_user_freq = (int)val;
+
+ return n;
+}
+static DEVICE_ATTR_RW(max_user_freq);
+
+/**
+ * hctosys_show - indicate if the given RTC set the system time
+ * @dev: The device that the attribute belongs to.
+ * @attr: The attribute being read.
+ * @buf: The result buffer.
+ *
+ * buf is "1" if the system clock was set by this RTC at the last
+ * boot or resume event.
+ */
+static ssize_t
+hctosys_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+#ifdef CONFIG_RTC_HCTOSYS_DEVICE
+ if (rtc_hctosys_ret == 0 &&
+ strcmp(dev_name(&to_rtc_device(dev)->dev),
+ CONFIG_RTC_HCTOSYS_DEVICE) == 0)
+ return sysfs_emit(buf, "1\n");
+#endif
+ return sysfs_emit(buf, "0\n");
+}
+static DEVICE_ATTR_RO(hctosys);
+
+static ssize_t
+wakealarm_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ struct rtc_wkalrm alm;
+
+ /* Don't show disabled alarms. For uniformity, RTC alarms are
+ * conceptually one-shot, even though some common RTCs (on PCs)
+ * don't actually work that way.
+ *
+ * NOTE: RTC implementations where the alarm doesn't match an
+ * exact YYYY-MM-DD HH:MM[:SS] date *must* disable their RTC
+ * alarms after they trigger, to ensure one-shot semantics.
+ */
+ retval = rtc_read_alarm(to_rtc_device(dev), &alm);
+ if (retval)
+ return retval;
+
+ if (alm.enabled)
+ return sysfs_emit(buf, "%lld\n", rtc_tm_to_time64(&alm.time));
+
+ return 0;
+}
+
+static ssize_t
+wakealarm_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t n)
+{
+ ssize_t retval;
+ time64_t now, alarm;
+ time64_t push = 0;
+ struct rtc_wkalrm alm;
+ struct rtc_device *rtc = to_rtc_device(dev);
+ const char *buf_ptr;
+ int adjust = 0;
+
+ /* Only request alarms that trigger in the future. Disable them
+ * by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
+ */
+ retval = rtc_read_time(rtc, &alm.time);
+ if (retval < 0)
+ return retval;
+ now = rtc_tm_to_time64(&alm.time);
+
+ buf_ptr = buf;
+ if (*buf_ptr == '+') {
+ buf_ptr++;
+ if (*buf_ptr == '=') {
+ buf_ptr++;
+ push = 1;
+ } else {
+ adjust = 1;
+ }
+ }
+ retval = kstrtos64(buf_ptr, 0, &alarm);
+ if (retval)
+ return retval;
+ if (adjust)
+ alarm += now;
+ if (alarm > now || push) {
+ /* Avoid accidentally clobbering active alarms; we can't
+ * entirely prevent that here, without even the minimal
+ * locking from the /dev/rtcN api.
+ */
+ retval = rtc_read_alarm(rtc, &alm);
+ if (retval < 0)
+ return retval;
+ if (alm.enabled) {
+ if (push) {
+ push = rtc_tm_to_time64(&alm.time);
+ alarm += push;
+ } else
+ return -EBUSY;
+ } else if (push)
+ return -EINVAL;
+ alm.enabled = 1;
+ } else {
+ alm.enabled = 0;
+
+ /* Provide a valid future alarm time. Linux isn't EFI,
+ * this time won't be ignored when disabling the alarm.
+ */
+ alarm = now + 300;
+ }
+ rtc_time64_to_tm(alarm, &alm.time);
+
+ retval = rtc_set_alarm(rtc, &alm);
+ return (retval < 0) ? retval : n;
+}
+static DEVICE_ATTR_RW(wakealarm);
+
+static ssize_t
+offset_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ ssize_t retval;
+ long offset;
+
+ retval = rtc_read_offset(to_rtc_device(dev), &offset);
+ if (retval)
+ return retval;
+
+ return sysfs_emit(buf, "%ld\n", offset);
+}
+
+static ssize_t
+offset_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t n)
+{
+ ssize_t retval;
+ long offset;
+
+ retval = kstrtol(buf, 10, &offset);
+ if (retval == 0)
+ retval = rtc_set_offset(to_rtc_device(dev), offset);
+
+ return (retval < 0) ? retval : n;
+}
+static DEVICE_ATTR_RW(offset);
+
+static ssize_t
+range_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "[%lld,%llu]\n", to_rtc_device(dev)->range_min,
+ to_rtc_device(dev)->range_max);
+}
+static DEVICE_ATTR_RO(range);
+
+static struct attribute *rtc_attrs[] = {
+ &dev_attr_name.attr,
+ &dev_attr_date.attr,
+ &dev_attr_time.attr,
+ &dev_attr_since_epoch.attr,
+ &dev_attr_max_user_freq.attr,
+ &dev_attr_hctosys.attr,
+ &dev_attr_wakealarm.attr,
+ &dev_attr_offset.attr,
+ &dev_attr_range.attr,
+ NULL,
+};
+
+/* The reason to trigger an alarm with no process watching it (via sysfs)
+ * is its side effect: waking from a system state like suspend-to-RAM or
+ * suspend-to-disk. So: no attribute unless that side effect is possible.
+ * (Userspace may disable that mechanism later.)
+ */
+static bool rtc_does_wakealarm(struct rtc_device *rtc)
+{
+ if (!device_can_wakeup(rtc->dev.parent))
+ return false;
+
+ return !!test_bit(RTC_FEATURE_ALARM, rtc->features);
+}
+
+static umode_t rtc_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct rtc_device *rtc = to_rtc_device(dev);
+ umode_t mode = attr->mode;
+
+ if (attr == &dev_attr_wakealarm.attr) {
+ if (!rtc_does_wakealarm(rtc))
+ mode = 0;
+ } else if (attr == &dev_attr_offset.attr) {
+ if (!rtc->ops->set_offset)
+ mode = 0;
+ } else if (attr == &dev_attr_range.attr) {
+ if (!(rtc->range_max - rtc->range_min))
+ mode = 0;
+ }
+
+ return mode;
+}
+
+static struct attribute_group rtc_attr_group = {
+ .is_visible = rtc_attr_is_visible,
+ .attrs = rtc_attrs,
+};
+__ATTRIBUTE_GROUPS(rtc_attr);
+
+const struct attribute_group **rtc_get_dev_attribute_groups(void)
+{
+ return rtc_attr_groups;
+}
+
+int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
+{
+ size_t old_cnt = 0, add_cnt = 0, new_cnt;
+ const struct attribute_group **groups, **old;
+
+ if (grps) {
+ for (groups = grps; *groups; groups++)
+ add_cnt++;
+ /* No need to modify current groups if nothing new is provided */
+ if (add_cnt == 0)
+ return 0;
+ } else {
+ return -EINVAL;
+ }
+
+ groups = rtc->dev.groups;
+ if (groups)
+ for (; *groups; groups++)
+ old_cnt++;
+
+ new_cnt = old_cnt + add_cnt + 1;
+ groups = devm_kcalloc(&rtc->dev, new_cnt, sizeof(*groups), GFP_KERNEL);
+ if (!groups)
+ return -ENOMEM;
+ memcpy(groups, rtc->dev.groups, old_cnt * sizeof(*groups));
+ memcpy(groups + old_cnt, grps, add_cnt * sizeof(*groups));
+ groups[old_cnt + add_cnt] = NULL;
+
+ old = rtc->dev.groups;
+ rtc->dev.groups = groups;
+ if (old && old != rtc_attr_groups)
+ devm_kfree(&rtc->dev, old);
+
+ return 0;
+}
+EXPORT_SYMBOL(rtc_add_groups);
+
+int rtc_add_group(struct rtc_device *rtc, const struct attribute_group *grp)
+{
+ const struct attribute_group *groups[] = { grp, NULL };
+
+ return rtc_add_groups(rtc, groups);
+}
+EXPORT_SYMBOL(rtc_add_group);