+++ /dev/null
-/*
- * 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_MS 60000 /* 60 seconds */
-#define WDT_MAX_TIMEOUT_MS 180000 /* 180 seconds */
-#define WDT_MIN_TIMEOUT_MS 1000 /* 1 second */
-#define WDT_DEFAULT_RESOLUTION_MS 1000 /* 1 second */
-
-static unsigned int wdt_max_timeout_ms = WDT_MAX_TIMEOUT_MS;
-static unsigned int wdt_resolution_ms = WDT_DEFAULT_RESOLUTION_MS;
-
-static unsigned int timeout_ms = WDT_TIMEOUT_MS;
-module_param(timeout_ms, uint, S_IRUGO);
-MODULE_PARM_DESC(timeout_ms, "Watchdog timeout in ms (default="
- __MODULE_STRING(WDT_TIMEOUT_MS) ")");
-
-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;
-}
-
-static int sun4v_wdt_ping(struct watchdog_device *wdd)
-{
- int hverr;
-
- hverr = sun4v_mach_set_watchdog(wdd->timeout, NULL);
- if (hverr == HV_EINVAL)
- return -EINVAL;
-
- return 0;
-}
-
-static int sun4v_wdt_set_timeout(struct watchdog_device *wdd,
- unsigned int timeout)
-{
- wdd->timeout = timeout - (timeout % wdt_resolution_ms);
-
- return 0;
-}
-
-static const struct watchdog_info sun4v_wdt_ident = {
- .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
- .identity = "sun4v hypervisor watchdog",
- .firmware_version = 0,
-};
-
-static 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_MS,
-};
-
-static int hvapi_registered;
-
-static int __init sun4v_wdt_init(void)
-{
- struct mdesc_handle *handle;
- u64 node;
- const u64 *value;
- int ret = 0;
- unsigned long major = 1, minor = 1;
-
- if (sun4v_hvapi_register(HV_GRP_CORE, major, &minor) != 0)
- return -ENODEV;
- if (minor < 1) {
- sun4v_hvapi_unregister(HV_GRP_CORE);
- return -ENODEV;
- }
- hvapi_registered = 1;
-
- /*
- * There are 2 properties that can be set from the control
- * domain for the watchdog.
- * watchdog-resolution
- * watchdog-max-timeout
- *
- * If there is no handle returned, this is no sun4v system
- * so it's correct to return -ENODEV. Same for missing of the
- * platform node.
- */
-
- handle = mdesc_grab();
- if (!handle)
- return -ENODEV;
-
- node = mdesc_node_by_name(handle, MDESC_NODE_NULL, "platform");
- if (node == MDESC_NODE_NULL) {
- mdesc_release(handle);
- return -ENODEV;
- }
-
- value = mdesc_get_property(handle, node, "watchdog-resolution", NULL);
- if (value) {
- wdt_resolution_ms = *value;
- if (wdt_resolution_ms == 0 ||
- wdt_resolution_ms > WDT_DEFAULT_RESOLUTION_MS)
- wdt_resolution_ms = WDT_DEFAULT_RESOLUTION_MS;
- }
-
- value = mdesc_get_property(handle, node, "watchdog-max-timeout", NULL);
- if (value) {
- wdt_max_timeout_ms = *value;
- /*
- * If the property is defined to be smaller than default
- * then set it to default.
- */
- if (wdt_max_timeout_ms < WDT_MIN_TIMEOUT_MS) {
- mdesc_release(handle);
- return -EINVAL;
- }
- }
-
- mdesc_release(handle);
-
- if (timeout_ms < WDT_MIN_TIMEOUT_MS)
- timeout_ms = WDT_MIN_TIMEOUT_MS;
- if (timeout_ms > WDT_MAX_TIMEOUT_MS)
- timeout_ms = WDT_MAX_TIMEOUT_MS;
- if (timeout_ms > wdt_max_timeout_ms)
- timeout_ms = wdt_max_timeout_ms;
-
- /*
- * round to nearest smaller value
- */
- wdt_max_timeout_ms -= wdt_max_timeout_ms % wdt_resolution_ms;
- timeout_ms -= timeout_ms % wdt_resolution_ms;
-
- wdd.max_timeout = wdt_max_timeout_ms;
- wdd.timeout = timeout_ms;
-
- watchdog_set_nowayout(&wdd, nowayout);
-
- ret = watchdog_register_device(&wdd);
- if (ret) {
- pr_err("Failed to register watchdog device\n");
- return ret;
- }
-
- pr_info("initialized (timeout_ms=%dms, nowayout=%d)\n",
- wdd.timeout, nowayout);
-
- return 0;
-}
-
-
-static void __exit sun4v_wdt_exit(void)
-{
- if (hvapi_registered)
- sun4v_hvapi_unregister(HV_GRP_CORE);
- sun4v_wdt_stop(&wdd);
- watchdog_unregister_device(&wdd);
-}
-
-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");
-MODULE_ALIAS("sun4v_wdt");
projects / users / jedix / linux-maple.git / commitdiff