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Release 4.14 drivers/watchdog/sun4v_wdt.c

Directory: drivers/watchdog
/*
 *      sun4v watchdog timer
 *      (c) Copyright 2016 Oracle Corporation
 *
 *      Implement a simple watchdog driver using the built-in sun4v hypervisor
 *      watchdog support. If time expires, the hypervisor stops or bounces
 *      the guest domain.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/watchdog.h>
#include <asm/hypervisor.h>
#include <asm/mdesc.h>


#define WDT_TIMEOUT			60

#define WDT_MAX_TIMEOUT			31536000

#define WDT_MIN_TIMEOUT			1

#define WDT_DEFAULT_RESOLUTION_MS	1000	
/* 1 second */


static unsigned int timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
	__MODULE_STRING(WDT_TIMEOUT) ")");


static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, S_IRUGO);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


static int sun4v_wdt_stop(struct watchdog_device *wdd) { sun4v_mach_set_watchdog(0, NULL); return 0; }

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Wim Coekaerts21100.00%1100.00%
Total21100.00%1100.00%


static int sun4v_wdt_ping(struct watchdog_device *wdd) { int hverr; /* * HV watchdog timer will round up the timeout * passed in to the nearest multiple of the * watchdog resolution in milliseconds. */ hverr = sun4v_mach_set_watchdog(wdd->timeout * 1000, NULL); if (hverr == HV_EINVAL) return -EINVAL; return 0; }

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static int sun4v_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { wdd->timeout = timeout; return 0; }

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Wim Coekaerts24100.00%1100.00%
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static const struct watchdog_info sun4v_wdt_ident = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .identity = "sun4v hypervisor watchdog", .firmware_version = 0, }; static const struct watchdog_ops sun4v_wdt_ops = { .owner = THIS_MODULE, .start = sun4v_wdt_ping, .stop = sun4v_wdt_stop, .ping = sun4v_wdt_ping, .set_timeout = sun4v_wdt_set_timeout, }; static struct watchdog_device wdd = { .info = &sun4v_wdt_ident, .ops = &sun4v_wdt_ops, .min_timeout = WDT_MIN_TIMEOUT, .max_timeout = WDT_MAX_TIMEOUT, .timeout = WDT_TIMEOUT, };
static int __init sun4v_wdt_init(void) { struct mdesc_handle *handle; u64 node; const u64 *value; int err = 0; unsigned long major = 1, minor = 1; /* * There are 2 properties that can be set from the control * domain for the watchdog. * watchdog-resolution * watchdog-max-timeout * * We can expect a handle to be returned otherwise something * serious is wrong. Correct to return -ENODEV here. */ handle = mdesc_grab(); if (!handle) return -ENODEV; node = mdesc_node_by_name(handle, MDESC_NODE_NULL, "platform"); err = -ENODEV; if (node == MDESC_NODE_NULL) goto out_release; /* * This is a safe way to validate if we are on the right * platform. */ if (sun4v_hvapi_register(HV_GRP_CORE, major, &minor)) goto out_hv_unreg; /* Allow value of watchdog-resolution up to 1s (default) */ value = mdesc_get_property(handle, node, "watchdog-resolution", NULL); err = -EINVAL; if (value) { if (*value == 0 || *value > WDT_DEFAULT_RESOLUTION_MS) goto out_hv_unreg; } value = mdesc_get_property(handle, node, "watchdog-max-timeout", NULL); if (value) { /* * If the property value (in ms) is smaller than * min_timeout, return -EINVAL. */ if (*value < wdd.min_timeout * 1000) goto out_hv_unreg; /* * If the property value is smaller than * default max_timeout then set watchdog max_timeout to * the value of the property in seconds. */ if (*value < wdd.max_timeout * 1000) wdd.max_timeout = *value / 1000; } watchdog_init_timeout(&wdd, timeout, NULL); watchdog_set_nowayout(&wdd, nowayout); err = watchdog_register_device(&wdd); if (err) goto out_hv_unreg; pr_info("initialized (timeout=%ds, nowayout=%d)\n", wdd.timeout, nowayout); mdesc_release(handle); return 0; out_hv_unreg: sun4v_hvapi_unregister(HV_GRP_CORE); out_release: mdesc_release(handle); return err; }

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Wim Coekaerts257100.00%1100.00%
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static void __exit sun4v_wdt_exit(void) { sun4v_hvapi_unregister(HV_GRP_CORE); watchdog_unregister_device(&wdd); }

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Wim Coekaerts20100.00%1100.00%
Total20100.00%1100.00%

module_init(sun4v_wdt_init); module_exit(sun4v_wdt_exit); MODULE_AUTHOR("Wim Coekaerts <wim.coekaerts@oracle.com>"); MODULE_DESCRIPTION("sun4v watchdog driver"); MODULE_LICENSE("GPL");

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Wim Coekaerts58399.83%150.00%
Bhumika Goyal10.17%150.00%
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Directory: drivers/watchdog
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