Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2015-2016 Mentor Graphics
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/watchdog.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include "watchdog_pretimeout.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) /* Default watchdog pretimeout governor */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) static struct watchdog_governor *default_gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) /* The spinlock protects default_gov, wdd->gov and pretimeout_list */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) static DEFINE_SPINLOCK(pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) /* List of watchdog devices, which can generate a pretimeout event */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) static LIST_HEAD(pretimeout_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) struct watchdog_pretimeout {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	struct watchdog_device		*wdd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	struct list_head		entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) /* The mutex protects governor list and serializes external interfaces */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) static DEFINE_MUTEX(governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) /* List of the registered watchdog pretimeout governors */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) static LIST_HEAD(governor_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) struct governor_priv {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	struct watchdog_governor	*gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct list_head		entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) static struct governor_priv *find_governor_by_name(const char *gov_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	struct governor_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	list_for_each_entry(priv, &governor_list, entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		if (sysfs_streq(gov_name, priv->gov->name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 			return priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) int watchdog_pretimeout_available_governors_get(char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	struct governor_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	mutex_lock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	list_for_each_entry(priv, &governor_list, entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 		count += sprintf(buf + count, "%s\n", priv->gov->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	mutex_unlock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	spin_lock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	if (wdd->gov)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 		count = sprintf(buf, "%s\n", wdd->gov->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	spin_unlock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 				     const char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	struct governor_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	mutex_lock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	priv = find_governor_by_name(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	if (!priv) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		mutex_unlock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	spin_lock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	wdd->gov = priv->gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	spin_unlock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	mutex_unlock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) void watchdog_notify_pretimeout(struct watchdog_device *wdd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	spin_lock_irqsave(&pretimeout_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	if (!wdd->gov) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		spin_unlock_irqrestore(&pretimeout_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	wdd->gov->pretimeout(wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	spin_unlock_irqrestore(&pretimeout_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) EXPORT_SYMBOL_GPL(watchdog_notify_pretimeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) int watchdog_register_governor(struct watchdog_governor *gov)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	struct watchdog_pretimeout *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	struct governor_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	if (!priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	mutex_lock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	if (find_governor_by_name(gov->name)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		mutex_unlock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		kfree(priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	priv->gov = gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	list_add(&priv->entry, &governor_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	if (!strncmp(gov->name, WATCHDOG_PRETIMEOUT_DEFAULT_GOV,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		     WATCHDOG_GOV_NAME_MAXLEN)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 		spin_lock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		default_gov = gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		list_for_each_entry(p, &pretimeout_list, entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 			if (!p->wdd->gov)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 				p->wdd->gov = default_gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		spin_unlock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	mutex_unlock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) EXPORT_SYMBOL(watchdog_register_governor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) void watchdog_unregister_governor(struct watchdog_governor *gov)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	struct watchdog_pretimeout *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	struct governor_priv *priv, *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	mutex_lock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	list_for_each_entry_safe(priv, t, &governor_list, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		if (priv->gov == gov) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 			list_del(&priv->entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 			kfree(priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	spin_lock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	list_for_each_entry(p, &pretimeout_list, entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		if (p->wdd->gov == gov)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 			p->wdd->gov = default_gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	spin_unlock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	mutex_unlock(&governor_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) EXPORT_SYMBOL(watchdog_unregister_governor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) int watchdog_register_pretimeout(struct watchdog_device *wdd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	struct watchdog_pretimeout *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	if (!(wdd->info->options & WDIOF_PRETIMEOUT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	p = kzalloc(sizeof(*p), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	if (!p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	spin_lock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	list_add(&p->entry, &pretimeout_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	p->wdd = wdd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	wdd->gov = default_gov;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	spin_unlock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) void watchdog_unregister_pretimeout(struct watchdog_device *wdd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	struct watchdog_pretimeout *p, *t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	if (!(wdd->info->options & WDIOF_PRETIMEOUT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	spin_lock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	wdd->gov = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	list_for_each_entry_safe(p, t, &pretimeout_list, entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		if (p->wdd == wdd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 			list_del(&p->entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	spin_unlock_irq(&pretimeout_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	kfree(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) }