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path: root/drivers/watchdog/diag288_wdt.c
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Diffstat (limited to 'drivers/watchdog/diag288_wdt.c')
-rw-r--r--drivers/watchdog/diag288_wdt.c200
1 files changed, 34 insertions, 166 deletions
diff --git a/drivers/watchdog/diag288_wdt.c b/drivers/watchdog/diag288_wdt.c
index 806a04a676b7..ea2b0171e70b 100644
--- a/drivers/watchdog/diag288_wdt.c
+++ b/drivers/watchdog/diag288_wdt.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Watchdog driver for z/VM and LPAR using the diag 288 interface.
*
@@ -5,10 +6,10 @@
* to CP.
*
* The command can be altered using the module parameter "cmd". This is
- * not recommended because it's only supported on z/VM but not whith LPAR.
+ * not recommended because it's only supported on z/VM but not with LPAR.
*
- * On LPAR, the watchdog will always trigger a system restart. the module
- * paramter cmd is meaningless here.
+ * On LPAR, the watchdog will always trigger a system restart. The module
+ * parameter cmd is meaningless here.
*
*
* Copyright IBM Corp. 2004, 2013
@@ -17,39 +18,23 @@
*
*/
-#define KMSG_COMPONENT "diag288_wdt"
-#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+#define pr_fmt(fmt) "diag288_wdt: " fmt
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
-#include <linux/miscdevice.h>
#include <linux/watchdog.h>
-#include <linux/suspend.h>
+#include <asm/machine.h>
#include <asm/ebcdic.h>
+#include <asm/diag288.h>
#include <asm/diag.h>
#include <linux/io.h>
-#include <linux/uaccess.h>
#define MAX_CMDLEN 240
#define DEFAULT_CMD "SYSTEM RESTART"
-#define MIN_INTERVAL 15 /* Minimal time supported by diag88 */
-#define MAX_INTERVAL 3600 /* One hour should be enough - pure estimation */
-
-#define WDT_DEFAULT_TIMEOUT 30
-
-/* Function codes - init, change, cancel */
-#define WDT_FUNC_INIT 0
-#define WDT_FUNC_CHANGE 1
-#define WDT_FUNC_CANCEL 2
-#define WDT_FUNC_CONCEAL 0x80000000
-
-/* Action codes for LPAR watchdog */
-#define LPARWDT_RESTART 0
-
static char wdt_cmd[MAX_CMDLEN] = DEFAULT_CMD;
static bool conceal_on;
static bool nowayout_info = WATCHDOG_NOWAYOUT;
@@ -69,82 +54,46 @@ MODULE_PARM_DESC(conceal, "Enable the CONCEAL CP option while the watchdog is ac
module_param_named(nowayout, nowayout_info, bool, 0444);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default = CONFIG_WATCHDOG_NOWAYOUT)");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("vmwatchdog");
-static int __diag288(unsigned int func, unsigned int timeout,
- unsigned long action, unsigned int len)
-{
- register unsigned long __func asm("2") = func;
- register unsigned long __timeout asm("3") = timeout;
- register unsigned long __action asm("4") = action;
- register unsigned long __len asm("5") = len;
- int err;
-
- err = -EINVAL;
- asm volatile(
- " diag %1, %3, 0x288\n"
- "0: la %0, 0\n"
- "1:\n"
- EX_TABLE(0b, 1b)
- : "+d" (err) : "d"(__func), "d"(__timeout),
- "d"(__action), "d"(__len) : "1", "cc");
- return err;
-}
+static char *cmd_buf;
-static int __diag288_vm(unsigned int func, unsigned int timeout,
- char *cmd, size_t len)
+static int diag288(unsigned int func, unsigned int timeout,
+ unsigned long action, unsigned int len)
{
diag_stat_inc(DIAG_STAT_X288);
- return __diag288(func, timeout, virt_to_phys(cmd), len);
+ return __diag288(func, timeout, action, len);
}
-static int __diag288_lpar(unsigned int func, unsigned int timeout,
- unsigned long action)
+static int diag288_str(unsigned int func, unsigned int timeout, char *cmd)
{
- diag_stat_inc(DIAG_STAT_X288);
- return __diag288(func, timeout, action, 0);
-}
+ ssize_t len;
-static unsigned long wdt_status;
+ len = strscpy(cmd_buf, cmd, MAX_CMDLEN);
+ if (len < 0)
+ return len;
+ ASCEBC(cmd_buf, MAX_CMDLEN);
+ EBC_TOUPPER(cmd_buf, MAX_CMDLEN);
-#define DIAG_WDOG_BUSY 0
+ return diag288(func, timeout, virt_to_phys(cmd_buf), len);
+}
static int wdt_start(struct watchdog_device *dev)
{
- char *ebc_cmd;
- size_t len;
int ret;
unsigned int func;
- if (test_and_set_bit(DIAG_WDOG_BUSY, &wdt_status))
- return -EBUSY;
-
- ret = -ENODEV;
-
- if (MACHINE_IS_VM) {
- ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
- if (!ebc_cmd) {
- clear_bit(DIAG_WDOG_BUSY, &wdt_status);
- return -ENOMEM;
- }
- len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
- ASCEBC(ebc_cmd, MAX_CMDLEN);
- EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
-
+ if (machine_is_vm()) {
func = conceal_on ? (WDT_FUNC_INIT | WDT_FUNC_CONCEAL)
: WDT_FUNC_INIT;
- ret = __diag288_vm(func, dev->timeout, ebc_cmd, len);
+ ret = diag288_str(func, dev->timeout, wdt_cmd);
WARN_ON(ret != 0);
- kfree(ebc_cmd);
} else {
- ret = __diag288_lpar(WDT_FUNC_INIT,
- dev->timeout, LPARWDT_RESTART);
+ ret = diag288(WDT_FUNC_INIT, dev->timeout, LPARWDT_RESTART, 0);
}
if (ret) {
pr_err("The watchdog cannot be activated\n");
- clear_bit(DIAG_WDOG_BUSY, &wdt_status);
return ret;
}
return 0;
@@ -152,33 +101,15 @@ static int wdt_start(struct watchdog_device *dev)
static int wdt_stop(struct watchdog_device *dev)
{
- int ret;
-
- diag_stat_inc(DIAG_STAT_X288);
- ret = __diag288(WDT_FUNC_CANCEL, 0, 0, 0);
-
- clear_bit(DIAG_WDOG_BUSY, &wdt_status);
-
- return ret;
+ return diag288(WDT_FUNC_CANCEL, 0, 0, 0);
}
static int wdt_ping(struct watchdog_device *dev)
{
- char *ebc_cmd;
- size_t len;
int ret;
unsigned int func;
- ret = -ENODEV;
-
- if (MACHINE_IS_VM) {
- ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
- if (!ebc_cmd)
- return -ENOMEM;
- len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
- ASCEBC(ebc_cmd, MAX_CMDLEN);
- EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
-
+ if (machine_is_vm()) {
/*
* It seems to be ok to z/VM to use the init function to
* retrigger the watchdog. On LPAR WDT_FUNC_CHANGE must
@@ -187,11 +118,10 @@ static int wdt_ping(struct watchdog_device *dev)
func = conceal_on ? (WDT_FUNC_INIT | WDT_FUNC_CONCEAL)
: WDT_FUNC_INIT;
- ret = __diag288_vm(func, dev->timeout, ebc_cmd, len);
+ ret = diag288_str(func, dev->timeout, wdt_cmd);
WARN_ON(ret != 0);
- kfree(ebc_cmd);
} else {
- ret = __diag288_lpar(WDT_FUNC_CHANGE, dev->timeout, 0);
+ ret = diag288(WDT_FUNC_CHANGE, dev->timeout, 0, 0);
}
if (ret)
@@ -229,88 +159,26 @@ static struct watchdog_device wdt_dev = {
.max_timeout = MAX_INTERVAL,
};
-/*
- * It makes no sense to go into suspend while the watchdog is running.
- * Depending on the memory size, the watchdog might trigger, while we
- * are still saving the memory.
- */
-static int wdt_suspend(void)
-{
- if (test_and_set_bit(DIAG_WDOG_BUSY, &wdt_status)) {
- pr_err("Linux cannot be suspended while the watchdog is in use\n");
- return notifier_from_errno(-EBUSY);
- }
- return NOTIFY_DONE;
-}
-
-static int wdt_resume(void)
-{
- clear_bit(DIAG_WDOG_BUSY, &wdt_status);
- return NOTIFY_DONE;
-}
-
-static int wdt_power_event(struct notifier_block *this, unsigned long event,
- void *ptr)
-{
- switch (event) {
- case PM_POST_HIBERNATION:
- case PM_POST_SUSPEND:
- return wdt_resume();
- case PM_HIBERNATION_PREPARE:
- case PM_SUSPEND_PREPARE:
- return wdt_suspend();
- default:
- return NOTIFY_DONE;
- }
-}
-
-static struct notifier_block wdt_power_notifier = {
- .notifier_call = wdt_power_event,
-};
-
static int __init diag288_init(void)
{
- int ret;
- char ebc_begin[] = {
- 194, 197, 199, 201, 213
- };
-
watchdog_set_nowayout(&wdt_dev, nowayout_info);
- if (MACHINE_IS_VM) {
- if (__diag288_vm(WDT_FUNC_INIT, 15,
- ebc_begin, sizeof(ebc_begin)) != 0) {
- pr_err("The watchdog cannot be initialized\n");
- return -EINVAL;
- }
- } else {
- if (__diag288_lpar(WDT_FUNC_INIT, 30, LPARWDT_RESTART)) {
+ if (machine_is_vm()) {
+ cmd_buf = kmalloc(MAX_CMDLEN, GFP_KERNEL);
+ if (!cmd_buf) {
pr_err("The watchdog cannot be initialized\n");
- return -EINVAL;
+ return -ENOMEM;
}
}
- if (__diag288_lpar(WDT_FUNC_CANCEL, 0, 0)) {
- pr_err("The watchdog cannot be deactivated\n");
- return -EINVAL;
- }
-
- ret = register_pm_notifier(&wdt_power_notifier);
- if (ret)
- return ret;
-
- ret = watchdog_register_device(&wdt_dev);
- if (ret)
- unregister_pm_notifier(&wdt_power_notifier);
-
- return ret;
+ return watchdog_register_device(&wdt_dev);
}
static void __exit diag288_exit(void)
{
watchdog_unregister_device(&wdt_dev);
- unregister_pm_notifier(&wdt_power_notifier);
+ kfree(cmd_buf);
}
-module_init(diag288_init);
+module_cpu_feature_match(S390_CPU_FEATURE_D288, diag288_init);
module_exit(diag288_exit);
generated by cgit (git 2.34.1) at 2025-12-26 07:45:22 +0000