msm-5.15/drivers/soc/qcom/qcom_wdt_core.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2021, The Linux Foundation. All rights reserved.
 * Copyright (c) 2021-2023, Qualcomm Innovation Center, Inc. All rights reserved.
 */
#include <linux/irqdomain.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/of.h>
#include <linux/cpu_pm.h>
#include <linux/platform_device.h>
#include <linux/wait.h>
#include <linux/reboot.h>
#include <linux/panic_notifier.h>
#include <linux/qcom_scm.h>
#include <soc/qcom/minidump.h>
#include <soc/qcom/watchdog.h>
#include <linux/cpumask.h>
#include <linux/cpu_pm.h>
#include <uapi/linux/sched/types.h>
#include <linux/sched/clock.h>
#include <linux/irq.h>
#include <linux/sort.h>
#include <linux/kernel_stat.h>
#include <linux/kallsyms.h>
#include <linux/kdebug.h>
#include <asm/hardirq.h>
#include <linux/suspend.h>
#include <linux/notifier.h>

#define MASK_SIZE        32
#define COMPARE_RET      -1

typedef int (*compare_t) (const void *lhs, const void *rhs);
static struct msm_watchdog_data *wdog_data;

static void qcom_wdt_dump_cpu_alive_mask(struct msm_watchdog_data *wdog_dd)
{
	static char alive_mask_buf[MASK_SIZE];

	scnprintf(alive_mask_buf, MASK_SIZE, "%*pb1", cpumask_pr_args(
				&wdog_dd->alive_mask));
	dev_info(wdog_dd->dev, "cpu alive mask from last pet %s\n",
				alive_mask_buf);
}

#ifdef CONFIG_QCOM_IRQ_STAT
static int cmp_irq_info_fn(const void *a, const void *b)
{
	struct qcom_irq_info *lhs = (struct qcom_irq_info *)a;
	struct qcom_irq_info *rhs = (struct qcom_irq_info *)b;

	if (lhs->total_count < rhs->total_count)
		return 1;

	if (lhs->total_count > rhs->total_count)
		return COMPARE_RET;

	return 0;
}

static void swap_irq_info_fn(void *a, void *b, int size)
{
	struct qcom_irq_info temp;
	struct qcom_irq_info *lhs = (struct qcom_irq_info *)a;
	struct qcom_irq_info *rhs = (struct qcom_irq_info *)b;

	temp = *lhs;
	*lhs = *rhs;
	*rhs = temp;
}

static struct qcom_irq_info *search(struct qcom_irq_info *key,
				    struct qcom_irq_info *base,
				    size_t num, compare_t cmp)
{
	struct qcom_irq_info *pivot = NULL;
	int result;

	while (num > 0) {
		pivot = base + (num >> 1);
		result = cmp(key, pivot);

		if (result == 0)
			goto out;

		if (result > 0) {
			base = pivot + 1;
			num--;
		}

		if (num)
			num >>= 1;
	}

out:
	if (pivot)
		pr_debug("*pivot:%u key:%u\n",
			pivot->total_count, key->total_count);

	return pivot;
}
/*
static void print_irq_stat(struct msm_watchdog_data *wdog_dd)
{
	int index;
	int cpu, ipi_nr;
	struct qcom_irq_info *info;

	pr_info("(virq:irq_count)- ");
	for (index = 0; index < NR_TOP_HITTERS; index++) {
		info = &wdog_dd->irq_counts[index];
		if (info->name) {
			if (info->chipname)
				pr_cont("%s:%s(%u):%u ", info->chipname,
					info->name, info->irq, info->total_count);
			else
				pr_cont("%s(%u):%u ", info->name,
					info->irq, info->total_count);
		} else {
			pr_cont("%u:%u ", info->irq, info->total_count);
		}
	}
	pr_cont("\n");

	pr_info("(cpu:irq_count)- ");
	for_each_possible_cpu(cpu)
		pr_cont("%u:%u ", cpu, wdog_dd->tot_irq_count[cpu]);
	pr_cont("\n");

	pr_info("(ipi:irq_count)- ");
	ipi_nr = nr_ipi_get();
	for (index = 0; index < ipi_nr; index++) {
		info = &wdog_dd->ipi_counts[index];
		pr_cont("%u:%u ", info->irq, info->total_count);
	}
	pr_cont("\n");
}
*/
static void compute_irq_stat(struct work_struct *work)
{
	unsigned int count;
	int index = 0, cpu, irq, ipi_nr;
	struct irq_desc *desc, **desc_ipi_arr;
	struct qcom_irq_info *pos;
	struct qcom_irq_info *start;
	struct qcom_irq_info key = {0};
	unsigned int running;
	struct msm_watchdog_data *wdog_dd = container_of(work,
					    struct msm_watchdog_data,
					    irq_counts_work);

	size_t arr_size = ARRAY_SIZE(wdog_dd->irq_counts);

	/* avoid parallel execution from bark handler and queued
	 * irq_counts_work.
	 */
	running = atomic_xchg(&wdog_dd->irq_counts_running, 1);
	if (running)
		return;

	/* per irq counts */
	rcu_read_lock();
	for_each_irq_nr(irq) {
		desc = irq_to_desc(irq);
		if (!desc)
			continue;

		count = kstat_irqs_usr(irq);
		if (!count)
			continue;

		if (index < arr_size) {
			wdog_dd->irq_counts[index].irq = irq;
			wdog_dd->irq_counts[index].total_count = count;
			wdog_dd->irq_counts[index].name = (desc->action) ?
					desc->action->name : NULL;
			wdog_dd->irq_counts[index].chipname = (desc->irq_data.chip) ?
					desc->irq_data.chip->name : NULL;
			for_each_possible_cpu(cpu)
				wdog_dd->irq_counts[index].irq_counter[cpu] =
					*per_cpu_ptr(desc->kstat_irqs, cpu);

			index++;
			if (index == arr_size)
				sort(wdog_dd->irq_counts, arr_size,
				     sizeof(*pos), cmp_irq_info_fn,
				     swap_irq_info_fn);

			continue;
		}

		key.total_count = count;
		start = wdog_dd->irq_counts + (arr_size - 1);
		pos = search(&key, wdog_dd->irq_counts,
			     arr_size, cmp_irq_info_fn);

		if (pos && (pos->total_count >= key.total_count)) {
			if (pos < start)
				pos++;
			else
				pos = NULL;
		}

		pr_debug("count :%u irq:%u\n", count, irq);
		if (pos && pos < start) {
			start--;
			for (; start >= pos ; start--)
				*(start + 1) = *start;
		}

		if (pos) {
			pos->irq = irq;
			pos->total_count = count;
			pos->name = (desc->action) ?
				desc->action->name : NULL;
			pos->chipname = (desc->irq_data.chip) ?
				desc->irq_data.chip->name : NULL;
			for_each_possible_cpu(cpu)
				pos->irq_counter[cpu] =
					*per_cpu_ptr(desc->kstat_irqs, cpu);
		}
	}
	rcu_read_unlock();

	/* per cpu total irq counts */
	for_each_possible_cpu(cpu)
		wdog_dd->tot_irq_count[cpu] = kstat_cpu_irqs_sum(cpu);

	/* per IPI counts */
	ipi_nr = nr_ipi_get();
	desc_ipi_arr = ipi_desc_get();
	for (index = 0; index < ipi_nr; index++) {
		wdog_dd->ipi_counts[index].total_count = 0;
		wdog_dd->ipi_counts[index].irq = index;
		irq = irq_desc_get_irq(desc_ipi_arr[index]);
		for_each_possible_cpu(cpu) {
			wdog_dd->ipi_counts[index].irq_counter[cpu] =
				kstat_irqs_cpu(irq, cpu);
			wdog_dd->ipi_counts[index].total_count +=
				wdog_dd->ipi_counts[index].irq_counter[cpu];
		}
	}

	//print_irq_stat(wdog_dd);
	atomic_xchg(&wdog_dd->irq_counts_running, 0);
}

static void queue_irq_counts_work(struct work_struct *irq_counts_work)
{
	queue_work(system_unbound_wq, irq_counts_work);
}
#else
static void queue_irq_counts_work(struct work_struct *irq_counts_work) { }
static void compute_irq_stat(struct work_struct *work) { }
#endif

static int qcom_wdt_hibernation_notifier(struct notifier_block *nb,
				unsigned long event, void *dummy)
{
	if (event == PM_HIBERNATION_PREPARE || ((event == PM_SUSPEND_PREPARE)
				&& pm_suspend_via_firmware()))
		wdog_data->hibernate = true;
	else if (event == PM_POST_HIBERNATION || ((event == PM_POST_SUSPEND)
				&& pm_suspend_via_firmware()))
		wdog_data->hibernate = false;
	return NOTIFY_OK;
}

static struct notifier_block qcom_wdt_notif_block = {
	.notifier_call = qcom_wdt_hibernation_notifier,
};

#ifdef CONFIG_PM_SLEEP
/**
 *  qcom_wdt_pet_suspend() - Suspends qcom watchdog functionality.
 *
 *  @dev: qcom watchdog device structure
 *
 *  All watchdogs should have the ability to be suspended, this
 *  will cause the watchdog counter to reset and HW counter will
 *  freeze when deepest low power mode is entered.
 *
 */
int qcom_wdt_pet_suspend(struct device *dev)
{
	struct msm_watchdog_data *wdog_data =
			(struct msm_watchdog_data *)dev_get_drvdata(dev);

	if (!wdog_data)
		return 0;

	if (wdog_data->user_pet_enabled)
		del_timer_sync(&wdog_data->user_pet_timer);

	spin_lock(&wdog_data->freeze_lock);
	wdog_data->freeze_in_progress = true;
	spin_unlock(&wdog_data->freeze_lock);
	wdog_data->ops->reset_wdt(wdog_data);
	del_timer_sync(&wdog_data->pet_timer);
	if (wdog_data->wakeup_irq_enable) {
		if (wdog_data->hibernate) {
			wdog_data->ops->disable_wdt(wdog_data);
			wdog_data->enabled = false;
		}
		wdog_data->last_pet = sched_clock();
		return 0;
	}

	wdog_data->ops->disable_wdt(wdog_data);
	wdog_data->enabled = false;
	wdog_data->last_pet = sched_clock();
	return 0;
}
EXPORT_SYMBOL(qcom_wdt_pet_suspend);

/**
 *  qcom_wdt_pet_resume() - Resumes qcom watchdog after a suspend.
 *
 *  @dev: qcom watchdog device structure
 *
 *  All watchdogs should have the ability to be resumed after a suspend.
 *  This will cause the watchdog counter to be reset and resumed.
 *
 */
int qcom_wdt_pet_resume(struct device *dev)
{
	uint32_t val;
	struct msm_watchdog_data *wdog_data =
			(struct msm_watchdog_data *)dev_get_drvdata(dev);
	unsigned long delay_time = 0;

	if (!wdog_data)
		return 0;

	val = BIT(EN);
	if (wdog_data->user_pet_enabled) {
		delay_time = msecs_to_jiffies(wdog_data->bark_time + 3 * 1000);
		wdog_data->user_pet_timer.expires = jiffies + delay_time;
		add_timer(&wdog_data->user_pet_timer);
	}

	delay_time = msecs_to_jiffies(wdog_data->pet_time);
	spin_lock(&wdog_data->freeze_lock);
	wdog_data->pet_timer.expires = jiffies + delay_time;
	add_timer(&wdog_data->pet_timer);
	wdog_data->freeze_in_progress = false;
	spin_unlock(&wdog_data->freeze_lock);
	if (wdog_data->wakeup_irq_enable) {
		if (wdog_data->hibernate) {
			wdog_data->ops->set_bark_time(wdog_data->bark_time, wdog_data);
			wdog_data->ops->set_bite_time(wdog_data->bark_time + 3 * 1000, wdog_data);
			val |= BIT(UNMASKED_INT_EN);
			wdog_data->ops->enable_wdt(val, wdog_data);
			wdog_data->enabled = true;
		}
		wdog_data->ops->reset_wdt(wdog_data);
		wdog_data->last_pet = sched_clock();
		return 0;
	}

	wdog_data->ops->enable_wdt(val, wdog_data);
	wdog_data->ops->reset_wdt(wdog_data);
	wdog_data->enabled = true;
	wdog_data->last_pet = sched_clock();
	return 0;
}
EXPORT_SYMBOL(qcom_wdt_pet_resume);
#endif

static void qcom_wdt_reset_on_oops(struct msm_watchdog_data *wdog_dd,
			int timeout)
{
	wdog_dd->ops->reset_wdt(wdog_dd);
	wdog_dd->ops->set_bark_time((timeout + 10) * 1000,
					wdog_dd);
	wdog_dd->ops->set_bite_time((timeout + 10) * 1000,
					wdog_dd);
}

static int qcom_wdt_panic_handler(struct notifier_block *this,
			      unsigned long event, void *ptr)
{
	struct msm_watchdog_data *wdog_dd = container_of(this,
				struct msm_watchdog_data, panic_blk);

	wdog_dd->in_panic = true;
	if (WDOG_BITE_EARLY_PANIC) {
		pr_info("Triggering early bite\n");
		qcom_wdt_trigger_bite();
	}
	if (panic_timeout == 0) {
		wdog_dd->ops->disable_wdt(wdog_dd);
	} else {
		qcom_wdt_reset_on_oops(wdog_dd, panic_timeout);
	}
	return NOTIFY_DONE;
}

#ifdef CONFIG_QCOM_MINIDUMP_PANIC_DUMP
static int qcom_wdt_die_handler(struct notifier_block *this,
				unsigned long val, void *data)
{
	struct msm_watchdog_data *wdog_dd = container_of(this,
				struct msm_watchdog_data, die_blk);

	qcom_wdt_reset_on_oops(wdog_dd, 5);
	return NOTIFY_DONE;
}

static void qcom_wdt_register_die_notifier(struct msm_watchdog_data *wdog_dd)
{
	wdog_dd->die_blk.notifier_call = qcom_wdt_die_handler;
	wdog_dd->die_blk.priority = INT_MAX - 1;
	register_die_notifier(&wdog_dd->die_blk);
}

static void qcom_wdt_unregister_die_notifier(struct msm_watchdog_data *wdog_dd)
{
	unregister_die_notifier(&wdog_dd->die_blk);
}
#else
static void qcom_wdt_register_die_notifier(struct msm_watchdog_data *wdog_dd) { }
static void qcom_wdt_unregister_die_notifier(struct msm_watchdog_data *wdog_dd) { }
#endif

static void qcom_wdt_disable(struct msm_watchdog_data *wdog_dd)
{
	wdog_dd->ops->disable_wdt(wdog_dd);

	if (wdog_dd->irq_ppi) {
		disable_percpu_irq(wdog_dd->bark_irq);
		free_percpu_irq(wdog_dd->bark_irq,
				(void __percpu *)wdog_dd->wdog_cpu_dd);
	} else {
		devm_free_irq(wdog_dd->dev, wdog_dd->bark_irq, wdog_dd);
	}

	wdog_dd->enabled = false;
	/*Ensure all cpus see update to enable*/
	smp_mb();
	atomic_notifier_chain_unregister(&panic_notifier_list,
						&wdog_dd->panic_blk);
	qcom_wdt_unregister_die_notifier(wdog_dd);
	unregister_restart_handler(&wdog_dd->restart_blk);
	del_timer_sync(&wdog_dd->pet_timer);
	if (wdog_dd->user_pet_enabled)
		del_timer_sync(&wdog_dd->user_pet_timer);
	wdog_dd->ops->disable_wdt(wdog_dd);
	dev_err(wdog_dd->dev, "QCOM Apps Watchdog deactivated\n");
}

static int restart_wdog_handler(struct notifier_block *this,
			       unsigned long event, void *ptr)
{
	struct msm_watchdog_data *wdog_dd = container_of(this,
				struct msm_watchdog_data, restart_blk);
	if (WDOG_BITE_ON_PANIC && wdog_dd->in_panic) {
		/*
		 * Trigger a watchdog bite here and if this fails,
		 * device will take the usual restart path.
		 */
		pr_info("Triggering late bite\n");
		qcom_wdt_trigger_bite();
	}
	return NOTIFY_DONE;
}

static ssize_t qcom_wdt_disable_get(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);
	int ret;
	int disable_val;

	mutex_lock(&wdog_dd->disable_lock);
	disable_val  = wdog_dd->enabled ? 0 : 1;
	ret = scnprintf(buf, PAGE_SIZE, "%d\n", disable_val);
	mutex_unlock(&wdog_dd->disable_lock);
	return ret;
}

static ssize_t qcom_wdt_disable_set(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);
	u8 disable;
	int ret;

	ret = kstrtou8(buf, 10, &disable);
	if (ret) {
		dev_err(wdog_dd->dev, "invalid user input\n");
		return ret;
	}
	if (disable == 1) {
		mutex_lock(&wdog_dd->disable_lock);
		if (!wdog_dd->enabled) {
			dev_err(wdog_dd->dev, "MSM Apps Watchdog already disabled\n");
			mutex_unlock(&wdog_dd->disable_lock);
			return count;
		}
		ret = qcom_scm_sec_wdog_deactivate();
		if (ret) {
			dev_err(wdog_dd->dev,
				"Failed to deactivate secure wdog, ret = %d\n",
				 ret);
		}
		qcom_wdt_disable(wdog_dd);
		mutex_unlock(&wdog_dd->disable_lock);
	} else {
		pr_err("invalid operation, only disable = 1 supported\n");
		return -EINVAL;
	}
	return count;
}

static DEVICE_ATTR(disable, 0600, qcom_wdt_disable_get, qcom_wdt_disable_set);

/*
 * Userspace Watchdog Support:
 * Write 1 to the "user_pet_enabled" file to enable hw support for a
 * userspace watchdog.
 * Userspace is required to pet the watchdog by continuing to write 1
 * to this file in the expected interval.
 * Userspace may disable this requirement by writing 0 to this same
 * file.
 */
static void __qcom_wdt_user_pet(struct msm_watchdog_data *wdog_dd)
{
	wdog_dd->user_pet_complete = true;
	wake_up(&wdog_dd->pet_complete);
}

static ssize_t qcom_wdt_user_pet_enabled_get(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);
	int ret;

	ret = scnprintf(buf, PAGE_SIZE, "%d\n",
			wdog_dd->user_pet_enabled);
	return ret;
}

static ssize_t qcom_wdt_user_pet_enabled_set(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);
	int ret;
	unsigned long delay_time = 0;
	bool already_enabled = wdog_dd->user_pet_enabled;

	ret = strtobool(buf, &wdog_dd->user_pet_enabled);
	if (ret) {
		dev_err(wdog_dd->dev, "invalid user input\n");
		return ret;
	}

	delay_time = msecs_to_jiffies(wdog_dd->bark_time + 3 * 1000);
	if (wdog_dd->user_pet_enabled)
		mod_timer(&wdog_dd->user_pet_timer, jiffies + delay_time);
	else if (already_enabled)
		del_timer_sync(&wdog_dd->user_pet_timer);

	__qcom_wdt_user_pet(wdog_dd);

	return count;
}

static DEVICE_ATTR(user_pet_enabled, 0600, qcom_wdt_user_pet_enabled_get,
						qcom_wdt_user_pet_enabled_set);

static ssize_t qcom_wdt_pet_time_get(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);
	int ret;

	ret = scnprintf(buf, PAGE_SIZE, "%d\n", wdog_dd->pet_time);
	return ret;
}

static DEVICE_ATTR(pet_time, 0400, qcom_wdt_pet_time_get, NULL);

static ssize_t wakeup_enable_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);

	return scnprintf(buf, PAGE_SIZE, "%d\n", wdog_dd->wakeup_irq_enable);
}
static ssize_t wakeup_enable_store(struct device *dev, struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct msm_watchdog_data *wdog_dd = dev_get_drvdata(dev);
	u8 enable;
	int ret;

	ret = kstrtou8(buf, 10, &enable);
	if (ret || enable > 1) {
		dev_err(wdog_dd->dev, "invalid user input\n");
		return ret ? : -EINVAL;
	}
	mutex_lock(&wdog_dd->disable_lock);
	/* echo 1 > wakeup_enable means wakeup irq is enabled */
	wdog_dd->wakeup_irq_enable = enable;
	if (wdog_dd->enabled) {
		u8 val = BIT(EN);

		if (wdog_dd->wakeup_irq_enable)
			val |= BIT(UNMASKED_INT_EN);
		wdog_dd->ops->enable_wdt(val, wdog_dd);
	}
	mutex_unlock(&wdog_dd->disable_lock);
	return count;
}
static DEVICE_ATTR_ADMIN_RW(wakeup_enable);

static void qcom_wdt_keep_alive_response(void *info)
{
	struct msm_watchdog_data *wdog_dd = info;
	int cpu = smp_processor_id();

	cpumask_set_cpu(cpu, &wdog_dd->alive_mask);
	wdog_dd->ping_end[cpu] = sched_clock();
	/* Make sure alive mask is cleared and set in order */
	smp_mb();
}

/*
 * If this function does not return, it implies one of the
 * other cpu's is not responsive.
 */
static void qcom_wdt_ping_other_cpus(struct msm_watchdog_data *wdog_dd)
{
	int cpu;

	cpumask_clear(&wdog_dd->alive_mask);
	/* Make sure alive mask is cleared and set in order */
	smp_mb();
	for_each_cpu(cpu, cpu_online_mask) {
		if (!wdog_dd->cpu_idle_pc_state[cpu]) {
			wdog_dd->ping_start[cpu] = sched_clock();
			smp_call_function_single(cpu,
						 qcom_wdt_keep_alive_response,
						 wdog_dd, 1);
		}
	}
}

static void qcom_wdt_pet_task_wakeup(struct timer_list *t)
{
	struct msm_watchdog_data *wdog_dd =
		from_timer(wdog_dd, t, pet_timer);
	wdog_dd->timer_expired = true;
	wdog_dd->timer_fired = sched_clock();
	wake_up(&wdog_dd->pet_complete);
}
static void qcom_wdt_user_pet_bite(struct timer_list *t)
{
	struct msm_watchdog_data *wdog_dd =
		from_timer(wdog_dd, t, user_pet_timer);
	if (!wdog_dd->user_pet_complete) {
		dev_info(wdog_dd->dev, "QCOM Apps Watchdog user pet timeout!\n");
		qcom_wdt_trigger_bite();
	}
}

static __ref int qcom_wdt_kthread(void *arg)
{
	struct msm_watchdog_data *wdog_dd = arg;
	unsigned long delay_time = 0;
	struct sched_param param = {.sched_priority = MAX_RT_PRIO-1};
	int ret, cpu;

	sched_setscheduler(current, SCHED_FIFO, &param);
	while (!kthread_should_stop()) {
		do {
			ret = wait_event_interruptible(wdog_dd->pet_complete,
						wdog_dd->timer_expired);
		} while (ret != 0);

		wdog_dd->thread_start = sched_clock();
		for_each_cpu(cpu, cpu_present_mask)
			wdog_dd->ping_start[cpu] = wdog_dd->ping_end[cpu] = 0;

		if (wdog_dd->do_ipi_ping)
			qcom_wdt_ping_other_cpus(wdog_dd);

		do {
			ret = wait_event_interruptible(wdog_dd->pet_complete,
						wdog_dd->user_pet_complete);
		} while (ret != 0);

		wdog_dd->timer_expired = false;
		wdog_dd->user_pet_complete = !wdog_dd->user_pet_enabled;

		if (wdog_dd->enabled) {
			delay_time = msecs_to_jiffies(wdog_dd->pet_time);
			wdog_dd->ops->reset_wdt(wdog_dd);
			wdog_dd->last_pet = sched_clock();
		}
		/* Check again before scheduling
		 * Could have been changed on other cpu
		 */
		if (!kthread_should_stop()) {
			spin_lock(&wdog_dd->freeze_lock);
			if (!wdog_dd->freeze_in_progress)
				mod_timer(&wdog_dd->pet_timer,
					jiffies + delay_time);
			spin_unlock(&wdog_dd->freeze_lock);
		}

		queue_irq_counts_work(&wdog_dd->irq_counts_work);
	}
	return 0;
}

static int qcom_wdt_cpu_pm_notify(struct notifier_block *this,
			      unsigned long action, void *v)
{
	struct msm_watchdog_data *wdog_dd = container_of(this,
				struct msm_watchdog_data, wdog_cpu_pm_nb);
	int cpu;

	cpu = raw_smp_processor_id();

	switch (action) {
	case CPU_PM_ENTER:
		wdog_dd->cpu_idle_pc_state[cpu] = 1;
		break;
	case CPU_PM_ENTER_FAILED:
	case CPU_PM_EXIT:
		wdog_dd->cpu_idle_pc_state[cpu] = 0;
		break;
	}

	return NOTIFY_OK;
}

/**
 * qcom_wdt_remove() - Removes the watchdog and stops it's kthread.
 *
 *  @pdev: watchdog platform_device
 *
 *  Upon the removal of the module all watchdog data along with the kthread
 *  will be cleaned up and the watchdog device will be removed from memory.
 *
 */
int qcom_wdt_remove(struct platform_device *pdev)
{
	struct msm_watchdog_data *wdog_dd = platform_get_drvdata(pdev);

	if (!IPI_CORES_IN_LPM)
		cpu_pm_unregister_notifier(&wdog_dd->wdog_cpu_pm_nb);

	mutex_lock(&wdog_dd->disable_lock);
	if (wdog_dd->enabled)
		qcom_wdt_disable(wdog_dd);

	mutex_unlock(&wdog_dd->disable_lock);
	device_remove_file(wdog_dd->dev, &dev_attr_disable);
	if (wdog_dd->irq_ppi)
		free_percpu((void __percpu *)wdog_dd->wdog_cpu_dd);
	irq_dispose_mapping(wdog_dd->bark_irq);
	dev_info(wdog_dd->dev, "QCOM Apps Watchdog Exit - Deactivated\n");
	del_timer_sync(&wdog_dd->pet_timer);
	if (wdog_dd->user_pet_enabled)
		del_timer_sync(&wdog_dd->user_pet_timer);
	wdog_dd->timer_expired = true;
	wdog_dd->user_pet_complete = true;
	kthread_stop(wdog_dd->watchdog_task);
	flush_work(&wdog_dd->irq_counts_work);
	return 0;
}
EXPORT_SYMBOL(qcom_wdt_remove);

/**
 * qcom_wdt_trigger_bite - Executes a watchdog bite.
 *
 * Return: function will not return, to allow for the bite to occur
 */
void qcom_wdt_trigger_bite(void)
{
	if (!wdog_data)
		return;
	compute_irq_stat(&wdog_data->irq_counts_work);
	dev_err(wdog_data->dev, "Causing a QCOM Apps Watchdog bite!\n");
	wdog_data->ops->show_wdt_status(wdog_data);
	wdog_data->ops->set_bite_time(1, wdog_data);
	wdog_data->ops->reset_wdt(wdog_data);
	/* Delay to make sure bite occurs */
	mdelay(10000);
	/*
	 * This function induces the non-secure bite and control
	 * should not return to the calling function. Non-secure
	 * bite interrupt is affined to all the cores and it may
	 * not be handled by the same cores which configured
	 * non-secure bite. So add forever loop here.
	 */
	while (1)
		udelay(1);

}
EXPORT_SYMBOL(qcom_wdt_trigger_bite);

static irqreturn_t qcom_wdt_bark_handler(int irq, void *dev_id)
{
	struct msm_watchdog_data *wdog_dd = dev_id;
	unsigned long nanosec_rem;
	unsigned long long t = sched_clock();

	nanosec_rem = do_div(t, 1000000000);
	dev_info(wdog_dd->dev, "QCOM Apps Watchdog bark! Now = %lu.%06lu\n",
			(unsigned long) t, nanosec_rem / 1000);

	nanosec_rem = do_div(wdog_dd->last_pet, 1000000000);
	dev_info(wdog_dd->dev, "QCOM Apps Watchdog last pet at %lu.%06lu\n",
			(unsigned long) wdog_dd->last_pet, nanosec_rem / 1000);
	if (wdog_dd->do_ipi_ping)
		qcom_wdt_dump_cpu_alive_mask(wdog_dd);

	if (wdog_dd->freeze_in_progress)
		dev_info(wdog_dd->dev, "Suspend in progress\n");

	md_dump_process();
	qcom_wdt_trigger_bite();

	return IRQ_HANDLED;
}

static irqreturn_t qcom_wdt_ppi_bark(int irq, void *dev_id_percpu)
{
	void *dev_id = raw_cpu_ptr((void __percpu *)dev_id_percpu);
	struct msm_watchdog_data *wdog_dd = *((struct msm_watchdog_data **)dev_id);

	return qcom_wdt_bark_handler(irq, wdog_dd);
}

static int qcom_wdt_init_sysfs(struct msm_watchdog_data *wdog_dd)
{
	int error = 0;

	error |= device_create_file(wdog_dd->dev, &dev_attr_disable);
	error |= device_create_file(wdog_dd->dev, &dev_attr_wakeup_enable);
	if (QCOM_WATCHDOG_USERSPACE_PET) {
		error |= device_create_file(wdog_dd->dev, &dev_attr_pet_time);
		error |= device_create_file(wdog_dd->dev,
					    &dev_attr_user_pet_enabled);
	}
	if (error)
		dev_err(wdog_dd->dev, "cannot create sysfs attribute\n");

	return error;
}

static int qcom_wdt_init(struct msm_watchdog_data *wdog_dd,
			struct platform_device *pdev)
{
	unsigned long delay_time;
	uint32_t val;
	int ret;
	void *wdog_cpu_dd_v;

	if (wdog_dd->irq_ppi) {
		wdog_dd->wdog_cpu_dd = alloc_percpu(struct msm_watchdog_data *);
		if (!wdog_dd->wdog_cpu_dd) {
			dev_err(wdog_dd->dev, "failed to allocate cpu data\n");
			return -ENOMEM;
		}
		wdog_cpu_dd_v = raw_cpu_ptr((void __percpu *)wdog_dd->wdog_cpu_dd);
		*((struct msm_watchdog_data **)wdog_cpu_dd_v) = wdog_dd;
		ret = request_percpu_irq(wdog_dd->bark_irq, qcom_wdt_ppi_bark,
					"apps_wdog_bark",
					(void __percpu *)wdog_dd->wdog_cpu_dd);
		if (ret) {
			dev_err(wdog_dd->dev, "failed to request bark irq\n");
			free_percpu((void __percpu *)wdog_dd->wdog_cpu_dd);
			return ret;
		}
	} else {
		ret = devm_request_irq(wdog_dd->dev, wdog_dd->bark_irq,
				qcom_wdt_bark_handler,
				IRQF_TRIGGER_RISING | IRQF_NO_SUSPEND,
				"apps_wdog_bark", wdog_dd);
		if (ret) {
			dev_err(wdog_dd->dev, "failed to request bark irq: %d\n", ret);
			return -EINVAL;
		}
	}

	wdog_data->hibernate = false;
	ret = register_pm_notifier(&qcom_wdt_notif_block);
	if (ret)
		return ret;

	INIT_WORK(&wdog_dd->irq_counts_work, compute_irq_stat);
	atomic_set(&wdog_dd->irq_counts_running, 0);
	delay_time = msecs_to_jiffies(wdog_dd->pet_time);
	wdog_dd->ops->set_bark_time(wdog_dd->bark_time, wdog_dd);
	wdog_dd->ops->set_bite_time(wdog_dd->bark_time + 3 * 1000, wdog_dd);
	wdog_dd->panic_blk.priority = INT_MAX - 1;
	wdog_dd->panic_blk.notifier_call = qcom_wdt_panic_handler;
	atomic_notifier_chain_register(&panic_notifier_list,
				       &wdog_dd->panic_blk);
	qcom_wdt_register_die_notifier(wdog_dd);
	wdog_dd->restart_blk.priority = 255;
	wdog_dd->restart_blk.notifier_call = restart_wdog_handler;
	register_restart_handler(&wdog_dd->restart_blk);
	mutex_init(&wdog_dd->disable_lock);
	init_waitqueue_head(&wdog_dd->pet_complete);
	wdog_dd->timer_expired = false;
	wdog_dd->user_pet_complete = true;
	wdog_dd->user_pet_enabled = false;
	spin_lock_init(&wdog_dd->freeze_lock);
	wdog_dd->freeze_in_progress = false;
	wake_up_process(wdog_dd->watchdog_task);
	timer_setup(&wdog_dd->pet_timer, qcom_wdt_pet_task_wakeup, 0);
	wdog_dd->pet_timer.expires = jiffies + delay_time;
	add_timer(&wdog_dd->pet_timer);
	timer_setup(&wdog_dd->user_pet_timer, qcom_wdt_user_pet_bite, 0);
	val = BIT(EN);
	if (wdog_dd->wakeup_irq_enable)
		val |= BIT(UNMASKED_INT_EN);

	ret = wdog_dd->ops->enable_wdt(val, wdog_dd);
	if (ret) {
		atomic_notifier_chain_unregister(&panic_notifier_list,
						 &wdog_dd->panic_blk);
		qcom_wdt_unregister_die_notifier(wdog_dd);
		unregister_restart_handler(&wdog_dd->restart_blk);

		if (wdog_dd->irq_ppi) {
			free_percpu_irq(wdog_dd->bark_irq,
					(void __percpu *)wdog_dd->wdog_cpu_dd);
			free_percpu((void __percpu *)wdog_dd->wdog_cpu_dd);
		}

		del_timer_sync(&wdog_dd->pet_timer);
		flush_work(&wdog_dd->irq_counts_work);
		dev_err(wdog_dd->dev, "Failed Initializing QCOM Apps Watchdog\n");
		return ret;
	}

	wdog_dd->ops->reset_wdt(wdog_dd);
	wdog_dd->last_pet = sched_clock();
	wdog_dd->enabled = true;

	qcom_wdt_init_sysfs(wdog_dd);

	if (wdog_dd->irq_ppi)
		enable_percpu_irq(wdog_dd->bark_irq, 0);
	if (!IPI_CORES_IN_LPM) {
		wdog_dd->wdog_cpu_pm_nb.notifier_call = qcom_wdt_cpu_pm_notify;
		cpu_pm_register_notifier(&wdog_dd->wdog_cpu_pm_nb);
	}
	dev_info(wdog_dd->dev, "QCOM Apps Watchdog Initialized\n");

	return 0;
}

static void qcom_wdt_dump_pdata(struct msm_watchdog_data *pdata)
{
	dev_dbg(pdata->dev, "wdog bark_time %d", pdata->bark_time);
	dev_dbg(pdata->dev, "wdog pet_time %d", pdata->pet_time);
	dev_dbg(pdata->dev, "wdog perform ipi ping %d", pdata->do_ipi_ping);
	dev_dbg(pdata->dev, "wdog base address is 0x%lx\n", (unsigned long)
								pdata->base);
}

static void qcom_wdt_dt_to_pdata(struct platform_device *pdev,
				struct msm_watchdog_data *pdata)
{
	pdata->bark_irq = platform_get_irq(pdev, 0);
	pdata->irq_ppi = irq_is_percpu(pdata->bark_irq);
	pdata->bark_time = QCOM_WATCHDOG_BARK_TIME;
	pdata->pet_time = QCOM_WATCHDOG_PET_TIME;
	pdata->do_ipi_ping = QCOM_WATCHDOG_IPI_PING;
	pdata->wakeup_irq_enable = QCOM_WATCHDOG_WAKEUP_ENABLE;
	qcom_wdt_dump_pdata(pdata);
}

/**
 *  qcom_wdt_register() - Creates QCOM Apps watchdog device.
 *
 *  @pdev: watchdog platform_device
 *  @ops:  watchdog operations
 *
 *  All QCOM Apps watchdogs should be created the same way, this acts
 *  as a framework for this purpose.
 *
 *  0 on success, negative errno on failure.
 */
int qcom_wdt_register(struct platform_device *pdev,
			struct msm_watchdog_data *wdog_dd,
			char *wdog_dd_name)
{
	struct md_region md_entry;
	int ret;

	if (!pdev || !wdog_dd || !wdog_dd_name) {
		pr_err("wdt_register input incorrect\n");
		return -EINVAL;
	}

	qcom_wdt_dt_to_pdata(pdev, wdog_dd);
	wdog_data = wdog_dd;
	wdog_dd->dev = &pdev->dev;
	platform_set_drvdata(pdev, wdog_dd);
	cpumask_clear(&wdog_dd->alive_mask);
	wdog_dd->watchdog_task = kthread_create(qcom_wdt_kthread, wdog_dd,
						wdog_dd_name);
	if (IS_ERR(wdog_dd->watchdog_task)) {
		ret = PTR_ERR(wdog_dd->watchdog_task);
		goto err;
	}
	ret = qcom_wdt_init(wdog_dd, pdev);
	if (ret) {
		kthread_stop(wdog_dd->watchdog_task);
		goto err;
	}

	/* Add wdog info to minidump table */
	strlcpy(md_entry.name, "KWDOGDATA", sizeof(md_entry.name));
	md_entry.virt_addr = (uintptr_t)wdog_dd;
	md_entry.phys_addr = virt_to_phys(wdog_dd);
	md_entry.size = sizeof(*wdog_dd);
	if (msm_minidump_add_region(&md_entry) < 0)
		dev_err(wdog_dd->dev, "Failed to add Wdt data in Minidump\n");

	return 0;
err:
	return ret;
}
EXPORT_SYMBOL(qcom_wdt_register);

MODULE_DESCRIPTION("QCOM Watchdog Driver Core");
MODULE_LICENSE("GPL v2");