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Date:   Tue, 30 Jul 2019 15:52:28 -0700
Message-Id: <20190730225228.126044-1-kaleshsingh@google.com>
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Subject: [PATCH] PM/sleep: Expose suspend stats in sysfs
From:   Kalesh Singh <kaleshsingh@google.com>
To:     rjw@rjwysocki.net, gregkh@linuxfoundation.org
Cc:     trong@google.com, trong@android.com, sspatil@google.com,
        hridya@google.com, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, Kalesh Singh <kaleshsingh@google.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Userspace can get suspend stats from the suspend stats debugfs node.
Since debugfs doesn't have stable ABI, expose suspend stats in
sysfs under /sys/power/suspend_stats.

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
 kernel/power/main.c | 77 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 75 insertions(+), 2 deletions(-)

diff --git a/kernel/power/main.c b/kernel/power/main.c
index bdbd605c4215..2a0edfcd50dc 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -254,7 +254,6 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
 power_attr(pm_test);
 #endif /* CONFIG_PM_SLEEP_DEBUG */
 
-#ifdef CONFIG_DEBUG_FS
 static char *suspend_step_name(enum suspend_stat_step step)
 {
 	switch (step) {
@@ -275,6 +274,72 @@ static char *suspend_step_name(enum suspend_stat_step step)
 	}
 }
 
+#define suspend_attr(_name)						\
+static ssize_t _name##_show(struct kobject *kobj,			\
+		struct kobj_attribute *attr, char *buf)			\
+{									\
+	int index;							\
+	enum suspend_stat_step step;					\
+	char *last_failed_stat = NULL;					\
+									\
+	if (strcmp(attr->attr.name, "last_failed_dev") == 0) {		\
+		index = suspend_stats._name + REC_FAILED_NUM - 1;	\
+		index %= REC_FAILED_NUM;				\
+		last_failed_stat = suspend_stats.failed_devs[index];	\
+		return sprintf(buf, "%s\n", last_failed_stat);		\
+	} else if (strcmp(attr->attr.name, "last_failed_step") == 0) {	\
+		index = suspend_stats._name + REC_FAILED_NUM - 1;	\
+		index %= REC_FAILED_NUM;				\
+		step = suspend_stats.failed_steps[index];		\
+		last_failed_stat = suspend_step_name(step);		\
+		return sprintf(buf, "%s\n", last_failed_stat);		\
+	} else if (strcmp(attr->attr.name, "last_failed_errno") == 0) {	\
+		index = suspend_stats._name + REC_FAILED_NUM - 1;	\
+		index %= REC_FAILED_NUM;				\
+		return sprintf(buf, "%d\n", suspend_stats.errno[index]);\
+	}								\
+									\
+	return sprintf(buf, "%d\n", suspend_stats._name);		\
+}									\
+static struct kobj_attribute _name = __ATTR_RO(_name)
+
+suspend_attr(success);
+suspend_attr(fail);
+suspend_attr(failed_freeze);
+suspend_attr(failed_prepare);
+suspend_attr(failed_suspend);
+suspend_attr(failed_suspend_late);
+suspend_attr(failed_suspend_noirq);
+suspend_attr(failed_resume);
+suspend_attr(failed_resume_early);
+suspend_attr(failed_resume_noirq);
+suspend_attr(last_failed_dev);
+suspend_attr(last_failed_errno);
+suspend_attr(last_failed_step);
+
+static struct attribute *suspend_attrs[] = {
+	&success.attr,
+	&fail.attr,
+	&failed_freeze.attr,
+	&failed_prepare.attr,
+	&failed_suspend.attr,
+	&failed_suspend_late.attr,
+	&failed_suspend_noirq.attr,
+	&failed_resume.attr,
+	&failed_resume_early.attr,
+	&failed_resume_noirq.attr,
+	&last_failed_dev.attr,
+	&last_failed_errno.attr,
+	&last_failed_step.attr,
+	NULL,
+};
+
+static struct attribute_group suspend_attr_group = {
+	.name = "suspend_stats",
+	.attrs = suspend_attrs,
+};
+
+#ifdef CONFIG_DEBUG_FS
 static int suspend_stats_show(struct seq_file *s, void *unused)
 {
 	int i, index, last_dev, last_errno, last_step;
@@ -794,6 +859,14 @@ static const struct attribute_group attr_group = {
 	.attrs = g,
 };
 
+static const struct attribute_group *attr_groups[] = {
+	&attr_group,
+#ifdef CONFIG_PM_SLEEP
+	&suspend_attr_group,
+#endif
+	NULL,
+};
+
 struct workqueue_struct *pm_wq;
 EXPORT_SYMBOL_GPL(pm_wq);
 
@@ -815,7 +888,7 @@ static int __init pm_init(void)
 	power_kobj = kobject_create_and_add("power", NULL);
 	if (!power_kobj)
 		return -ENOMEM;
-	error = sysfs_create_group(power_kobj, &attr_group);
+	error = sysfs_create_groups(power_kobj, attr_groups);
 	if (error)
 		return error;
 	pm_print_times_init();
-- 
2.22.0.770.g0f2c4a37fd-goog