ASR_BASE

Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/kernel/power/wakeup_reason.c b/marvell/linux/kernel/power/wakeup_reason.c
new file mode 100644
index 0000000..6c9f16a
--- /dev/null
+++ b/marvell/linux/kernel/power/wakeup_reason.c
@@ -0,0 +1,438 @@
+/*
+ * kernel/power/wakeup_reason.c
+ *
+ * Logs the reasons which caused the kernel to resume from
+ * the suspend mode.
+ *
+ * Copyright (C) 2020 Google, Inc.
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/wakeup_reason.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/notifier.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+
+/*
+ * struct wakeup_irq_node - stores data and relationships for IRQs logged as
+ * either base or nested wakeup reasons during suspend/resume flow.
+ * @siblings - for membership on leaf or parent IRQ lists
+ * @irq      - the IRQ number
+ * @irq_name - the name associated with the IRQ, or a default if none
+ */
+struct wakeup_irq_node {
+	struct list_head siblings;
+	int irq;
+	const char *irq_name;
+};
+
+enum wakeup_reason_flag {
+	RESUME_NONE = 0,
+	RESUME_IRQ,
+	RESUME_ABORT,
+	RESUME_ABNORMAL,
+};
+
+static DEFINE_SPINLOCK(wakeup_reason_lock);
+
+static LIST_HEAD(leaf_irqs);   /* kept in ascending IRQ sorted order */
+static LIST_HEAD(parent_irqs); /* unordered */
+
+static struct kmem_cache *wakeup_irq_nodes_cache;
+
+static const char *default_irq_name = "(unnamed)";
+
+static struct kobject *kobj;
+
+static bool capture_reasons;
+static int wakeup_reason;
+static char non_irq_wake_reason[MAX_SUSPEND_ABORT_LEN];
+
+static ktime_t last_monotime; /* monotonic time before last suspend */
+static ktime_t curr_monotime; /* monotonic time after last suspend */
+static ktime_t last_stime; /* monotonic boottime offset before last suspend */
+static ktime_t curr_stime; /* monotonic boottime offset after last suspend */
+
+static void init_node(struct wakeup_irq_node *p, int irq)
+{
+	struct irq_desc *desc;
+
+	INIT_LIST_HEAD(&p->siblings);
+
+	p->irq = irq;
+	desc = irq_to_desc(irq);
+	if (desc && desc->action && desc->action->name)
+		p->irq_name = desc->action->name;
+	else
+		p->irq_name = default_irq_name;
+}
+
+static struct wakeup_irq_node *create_node(int irq)
+{
+	struct wakeup_irq_node *result;
+
+	result = kmem_cache_alloc(wakeup_irq_nodes_cache, GFP_ATOMIC);
+	if (unlikely(!result))
+		pr_warn("Failed to log wakeup IRQ %d\n", irq);
+	else
+		init_node(result, irq);
+
+	return result;
+}
+
+static void delete_list(struct list_head *head)
+{
+	struct wakeup_irq_node *n;
+
+	while (!list_empty(head)) {
+		n = list_first_entry(head, struct wakeup_irq_node, siblings);
+		list_del(&n->siblings);
+		kmem_cache_free(wakeup_irq_nodes_cache, n);
+	}
+}
+
+static bool add_sibling_node_sorted(struct list_head *head, int irq)
+{
+	struct wakeup_irq_node *n = NULL;
+	struct list_head *predecessor = head;
+
+	if (unlikely(WARN_ON(!head)))
+		return NULL;
+
+	if (!list_empty(head))
+		list_for_each_entry(n, head, siblings) {
+			if (n->irq < irq)
+				predecessor = &n->siblings;
+			else if (n->irq == irq)
+				return true;
+			else
+				break;
+		}
+
+	n = create_node(irq);
+	if (n) {
+		list_add(&n->siblings, predecessor);
+		return true;
+	}
+
+	return false;
+}
+
+static struct wakeup_irq_node *find_node_in_list(struct list_head *head,
+						 int irq)
+{
+	struct wakeup_irq_node *n;
+
+	if (unlikely(WARN_ON(!head)))
+		return NULL;
+
+	list_for_each_entry(n, head, siblings)
+		if (n->irq == irq)
+			return n;
+
+	return NULL;
+}
+
+void log_irq_wakeup_reason(int irq)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&wakeup_reason_lock, flags);
+	if (wakeup_reason == RESUME_ABNORMAL || wakeup_reason == RESUME_ABORT) {
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return;
+	}
+
+	if (!capture_reasons) {
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return;
+	}
+
+	if (find_node_in_list(&parent_irqs, irq) == NULL)
+		add_sibling_node_sorted(&leaf_irqs, irq);
+
+	wakeup_reason = RESUME_IRQ;
+	spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+}
+
+void log_threaded_irq_wakeup_reason(int irq, int parent_irq)
+{
+	struct wakeup_irq_node *parent;
+	unsigned long flags;
+
+	/*
+	 * Intentionally unsynchronized.  Calls that come in after we have
+	 * resumed should have a fast exit path since there's no work to be
+	 * done, any any coherence issue that could cause a wrong value here is
+	 * both highly improbable - given the set/clear timing - and very low
+	 * impact (parent IRQ gets logged instead of the specific child).
+	 */
+	if (!capture_reasons)
+		return;
+
+	spin_lock_irqsave(&wakeup_reason_lock, flags);
+
+	if (wakeup_reason == RESUME_ABNORMAL || wakeup_reason == RESUME_ABORT) {
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return;
+	}
+
+	if (!capture_reasons || (find_node_in_list(&leaf_irqs, irq) != NULL)) {
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return;
+	}
+
+	parent = find_node_in_list(&parent_irqs, parent_irq);
+	if (parent != NULL)
+		add_sibling_node_sorted(&leaf_irqs, irq);
+	else {
+		parent = find_node_in_list(&leaf_irqs, parent_irq);
+		if (parent != NULL) {
+			list_del_init(&parent->siblings);
+			list_add_tail(&parent->siblings, &parent_irqs);
+			add_sibling_node_sorted(&leaf_irqs, irq);
+		}
+	}
+
+	spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+}
+EXPORT_SYMBOL_GPL(log_threaded_irq_wakeup_reason);
+
+static void __log_abort_or_abnormal_wake(bool abort, const char *fmt,
+					 va_list args)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&wakeup_reason_lock, flags);
+
+	/* Suspend abort or abnormal wake reason has already been logged. */
+	if (wakeup_reason != RESUME_NONE) {
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return;
+	}
+
+	if (abort)
+		wakeup_reason = RESUME_ABORT;
+	else
+		wakeup_reason = RESUME_ABNORMAL;
+
+	vsnprintf(non_irq_wake_reason, MAX_SUSPEND_ABORT_LEN, fmt, args);
+
+	spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+}
+
+void log_suspend_abort_reason(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	__log_abort_or_abnormal_wake(true, fmt, args);
+	va_end(args);
+}
+EXPORT_SYMBOL_GPL(log_suspend_abort_reason);
+
+void log_abnormal_wakeup_reason(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	__log_abort_or_abnormal_wake(false, fmt, args);
+	va_end(args);
+}
+EXPORT_SYMBOL_GPL(log_abnormal_wakeup_reason);
+
+void clear_wakeup_reasons(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&wakeup_reason_lock, flags);
+
+	delete_list(&leaf_irqs);
+	delete_list(&parent_irqs);
+	wakeup_reason = RESUME_NONE;
+	capture_reasons = true;
+
+	spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+}
+
+static void print_wakeup_sources(void)
+{
+	struct wakeup_irq_node *n;
+	unsigned long flags;
+
+	spin_lock_irqsave(&wakeup_reason_lock, flags);
+
+	capture_reasons = false;
+
+	if (wakeup_reason == RESUME_ABORT) {
+		pr_info("Abort: %s\n", non_irq_wake_reason);
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return;
+	}
+
+	if (wakeup_reason == RESUME_IRQ && !list_empty(&leaf_irqs))
+		list_for_each_entry(n, &leaf_irqs, siblings)
+			pr_pm_debug("Resume caused by IRQ %d, %s\n", n->irq,
+				n->irq_name);
+	else if (wakeup_reason == RESUME_ABNORMAL)
+		pr_pm_debug("Resume caused by %s\n", non_irq_wake_reason);
+	else
+		pr_pm_debug("Resume cause unknown\n");
+
+	spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+}
+
+static ssize_t last_resume_reason_show(struct kobject *kobj,
+				       struct kobj_attribute *attr, char *buf)
+{
+	ssize_t buf_offset = 0;
+	struct wakeup_irq_node *n;
+	unsigned long flags;
+
+	spin_lock_irqsave(&wakeup_reason_lock, flags);
+
+	if (wakeup_reason == RESUME_ABORT) {
+		buf_offset = scnprintf(buf, PAGE_SIZE, "Abort: %s",
+				       non_irq_wake_reason);
+		spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+		return buf_offset;
+	}
+
+	if (wakeup_reason == RESUME_IRQ && !list_empty(&leaf_irqs))
+		list_for_each_entry(n, &leaf_irqs, siblings)
+			buf_offset += scnprintf(buf + buf_offset,
+						PAGE_SIZE - buf_offset,
+						"%d %s\n", n->irq, n->irq_name);
+	else if (wakeup_reason == RESUME_ABNORMAL)
+		buf_offset = scnprintf(buf, PAGE_SIZE, "-1 %s",
+				       non_irq_wake_reason);
+
+	spin_unlock_irqrestore(&wakeup_reason_lock, flags);
+
+	return buf_offset;
+}
+
+static ssize_t last_suspend_time_show(struct kobject *kobj,
+			struct kobj_attribute *attr, char *buf)
+{
+	struct timespec64 sleep_time;
+	struct timespec64 total_time;
+	struct timespec64 suspend_resume_time;
+
+	/*
+	 * total_time is calculated from monotonic bootoffsets because
+	 * unlike CLOCK_MONOTONIC it include the time spent in suspend state.
+	 */
+	total_time = ktime_to_timespec64(ktime_sub(curr_stime, last_stime));
+
+	/*
+	 * suspend_resume_time is calculated as monotonic (CLOCK_MONOTONIC)
+	 * time interval before entering suspend and post suspend.
+	 */
+	suspend_resume_time =
+		ktime_to_timespec64(ktime_sub(curr_monotime, last_monotime));
+
+	/* sleep_time = total_time - suspend_resume_time */
+	sleep_time = timespec64_sub(total_time, suspend_resume_time);
+
+	/* Export suspend_resume_time and sleep_time in pair here. */
+	return sprintf(buf, "%llu.%09lu %llu.%09lu\n",
+		       (unsigned long long)suspend_resume_time.tv_sec,
+		       suspend_resume_time.tv_nsec,
+		       (unsigned long long)sleep_time.tv_sec,
+		       sleep_time.tv_nsec);
+}
+
+static struct kobj_attribute resume_reason = __ATTR_RO(last_resume_reason);
+static struct kobj_attribute suspend_time = __ATTR_RO(last_suspend_time);
+
+static struct attribute *attrs[] = {
+	&resume_reason.attr,
+	&suspend_time.attr,
+	NULL,
+};
+static struct attribute_group attr_group = {
+	.attrs = attrs,
+};
+
+/* Detects a suspend and clears all the previous wake up reasons*/
+static int wakeup_reason_pm_event(struct notifier_block *notifier,
+		unsigned long pm_event, void *unused)
+{
+	switch (pm_event) {
+	case PM_SUSPEND_PREPARE:
+		/* monotonic time since boot */
+		last_monotime = ktime_get();
+		/* monotonic time since boot including the time spent in suspend */
+		last_stime = ktime_get_boottime();
+		clear_wakeup_reasons();
+		break;
+	case PM_POST_SUSPEND:
+		/* monotonic time since boot */
+		curr_monotime = ktime_get();
+		/* monotonic time since boot including the time spent in suspend */
+		curr_stime = ktime_get_boottime();
+		print_wakeup_sources();
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block wakeup_reason_pm_notifier_block = {
+	.notifier_call = wakeup_reason_pm_event,
+};
+
+static int __init wakeup_reason_init(void)
+{
+	if (register_pm_notifier(&wakeup_reason_pm_notifier_block)) {
+		pr_warn("[%s] failed to register PM notifier\n", __func__);
+		goto fail;
+	}
+
+	kobj = kobject_create_and_add("wakeup_reasons", kernel_kobj);
+	if (!kobj) {
+		pr_warn("[%s] failed to create a sysfs kobject\n", __func__);
+		goto fail_unregister_pm_notifier;
+	}
+
+	if (sysfs_create_group(kobj, &attr_group)) {
+		pr_warn("[%s] failed to create a sysfs group\n", __func__);
+		goto fail_kobject_put;
+	}
+
+	wakeup_irq_nodes_cache =
+		kmem_cache_create("wakeup_irq_node_cache",
+				  sizeof(struct wakeup_irq_node), 0, 0, NULL);
+	if (!wakeup_irq_nodes_cache)
+		goto fail_remove_group;
+
+	return 0;
+
+fail_remove_group:
+	sysfs_remove_group(kobj, &attr_group);
+fail_kobject_put:
+	kobject_put(kobj);
+fail_unregister_pm_notifier:
+	unregister_pm_notifier(&wakeup_reason_pm_notifier_block);
+fail:
+	return 1;
+}
+
+late_initcall(wakeup_reason_init);