cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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bcm47xx_wdt.c (5890B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 *  Watchdog driver for Broadcom BCM47XX
      4 *
      5 *  Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
      6 *  Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
      7 *  Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de>
      8 *
      9 */
     10
     11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
     12
     13#include <linux/bcm47xx_wdt.h>
     14#include <linux/bitops.h>
     15#include <linux/errno.h>
     16#include <linux/kernel.h>
     17#include <linux/module.h>
     18#include <linux/moduleparam.h>
     19#include <linux/platform_device.h>
     20#include <linux/types.h>
     21#include <linux/watchdog.h>
     22#include <linux/timer.h>
     23#include <linux/jiffies.h>
     24
     25#define DRV_NAME		"bcm47xx_wdt"
     26
     27#define WDT_DEFAULT_TIME	30	/* seconds */
     28#define WDT_SOFTTIMER_MAX	255	/* seconds */
     29#define WDT_SOFTTIMER_THRESHOLD	60	/* seconds */
     30
     31static int timeout = WDT_DEFAULT_TIME;
     32static bool nowayout = WATCHDOG_NOWAYOUT;
     33
     34module_param(timeout, int, 0);
     35MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
     36				__MODULE_STRING(WDT_DEFAULT_TIME) ")");
     37
     38module_param(nowayout, bool, 0);
     39MODULE_PARM_DESC(nowayout,
     40		"Watchdog cannot be stopped once started (default="
     41				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
     42
     43static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
     44{
     45	return container_of(wdd, struct bcm47xx_wdt, wdd);
     46}
     47
     48static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
     49{
     50	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
     51
     52	wdt->timer_set_ms(wdt, wdd->timeout * 1000);
     53
     54	return 0;
     55}
     56
     57static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
     58{
     59	return 0;
     60}
     61
     62static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
     63{
     64	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
     65
     66	wdt->timer_set(wdt, 0);
     67
     68	return 0;
     69}
     70
     71static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
     72					unsigned int new_time)
     73{
     74	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
     75	u32 max_timer = wdt->max_timer_ms;
     76
     77	if (new_time < 1 || new_time > max_timer / 1000) {
     78		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
     79			max_timer / 1000, new_time);
     80		return -EINVAL;
     81	}
     82
     83	wdd->timeout = new_time;
     84	return 0;
     85}
     86
     87static int bcm47xx_wdt_restart(struct watchdog_device *wdd,
     88			       unsigned long action, void *data)
     89{
     90	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
     91
     92	wdt->timer_set(wdt, 1);
     93
     94	return 0;
     95}
     96
     97static const struct watchdog_ops bcm47xx_wdt_hard_ops = {
     98	.owner		= THIS_MODULE,
     99	.start		= bcm47xx_wdt_hard_start,
    100	.stop		= bcm47xx_wdt_hard_stop,
    101	.ping		= bcm47xx_wdt_hard_keepalive,
    102	.set_timeout	= bcm47xx_wdt_hard_set_timeout,
    103	.restart        = bcm47xx_wdt_restart,
    104};
    105
    106static void bcm47xx_wdt_soft_timer_tick(struct timer_list *t)
    107{
    108	struct bcm47xx_wdt *wdt = from_timer(wdt, t, soft_timer);
    109	u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);
    110
    111	if (!atomic_dec_and_test(&wdt->soft_ticks)) {
    112		wdt->timer_set_ms(wdt, next_tick);
    113		mod_timer(&wdt->soft_timer, jiffies + HZ);
    114	} else {
    115		pr_crit("Watchdog will fire soon!!!\n");
    116	}
    117}
    118
    119static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
    120{
    121	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
    122
    123	atomic_set(&wdt->soft_ticks, wdd->timeout);
    124
    125	return 0;
    126}
    127
    128static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
    129{
    130	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
    131
    132	bcm47xx_wdt_soft_keepalive(wdd);
    133	bcm47xx_wdt_soft_timer_tick(&wdt->soft_timer);
    134
    135	return 0;
    136}
    137
    138static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
    139{
    140	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
    141
    142	del_timer_sync(&wdt->soft_timer);
    143	wdt->timer_set(wdt, 0);
    144
    145	return 0;
    146}
    147
    148static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
    149					unsigned int new_time)
    150{
    151	if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
    152		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
    153			WDT_SOFTTIMER_MAX, new_time);
    154		return -EINVAL;
    155	}
    156
    157	wdd->timeout = new_time;
    158	return 0;
    159}
    160
    161static const struct watchdog_info bcm47xx_wdt_info = {
    162	.identity	= DRV_NAME,
    163	.options	= WDIOF_SETTIMEOUT |
    164				WDIOF_KEEPALIVEPING |
    165				WDIOF_MAGICCLOSE,
    166};
    167
    168static const struct watchdog_ops bcm47xx_wdt_soft_ops = {
    169	.owner		= THIS_MODULE,
    170	.start		= bcm47xx_wdt_soft_start,
    171	.stop		= bcm47xx_wdt_soft_stop,
    172	.ping		= bcm47xx_wdt_soft_keepalive,
    173	.set_timeout	= bcm47xx_wdt_soft_set_timeout,
    174	.restart        = bcm47xx_wdt_restart,
    175};
    176
    177static int bcm47xx_wdt_probe(struct platform_device *pdev)
    178{
    179	int ret;
    180	bool soft;
    181	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
    182
    183	if (!wdt)
    184		return -ENXIO;
    185
    186	soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;
    187
    188	if (soft) {
    189		wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
    190		timer_setup(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick, 0);
    191	} else {
    192		wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
    193	}
    194
    195	wdt->wdd.info = &bcm47xx_wdt_info;
    196	wdt->wdd.timeout = WDT_DEFAULT_TIME;
    197	wdt->wdd.parent = &pdev->dev;
    198	ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
    199	if (ret)
    200		goto err_timer;
    201	watchdog_set_nowayout(&wdt->wdd, nowayout);
    202	watchdog_set_restart_priority(&wdt->wdd, 64);
    203	watchdog_stop_on_reboot(&wdt->wdd);
    204
    205	ret = watchdog_register_device(&wdt->wdd);
    206	if (ret)
    207		goto err_timer;
    208
    209	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
    210		timeout, nowayout ? ", nowayout" : "",
    211		soft ? ", Software Timer" : "");
    212	return 0;
    213
    214err_timer:
    215	if (soft)
    216		del_timer_sync(&wdt->soft_timer);
    217
    218	return ret;
    219}
    220
    221static int bcm47xx_wdt_remove(struct platform_device *pdev)
    222{
    223	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
    224
    225	watchdog_unregister_device(&wdt->wdd);
    226
    227	return 0;
    228}
    229
    230static struct platform_driver bcm47xx_wdt_driver = {
    231	.driver		= {
    232		.name	= "bcm47xx-wdt",
    233	},
    234	.probe		= bcm47xx_wdt_probe,
    235	.remove		= bcm47xx_wdt_remove,
    236};
    237
    238module_platform_driver(bcm47xx_wdt_driver);
    239
    240MODULE_AUTHOR("Aleksandar Radovanovic");
    241MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
    242MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
    243MODULE_LICENSE("GPL");