tegrakernel/kernel/kernel-4.9/drivers/watchdog/hpwdt.c

445 lines
9.9 KiB
C

/*
* HPE WatchDog Driver
* based on
*
* SoftDog 0.05: A Software Watchdog Device
*
* (c) Copyright 2015 Hewlett Packard Enterprise Development LP
* Thomas Mingarelli <thomas.mingarelli@hpe.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <asm/nmi.h>
#define HPWDT_VERSION "1.4.0"
#define SECS_TO_TICKS(secs) ((secs) * 1000 / 128)
#define TICKS_TO_SECS(ticks) ((ticks) * 128 / 1000)
#define HPWDT_MAX_TIMER TICKS_TO_SECS(65535)
#define DEFAULT_MARGIN 30
static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
static unsigned int reload; /* the computed soft_margin */
static bool nowayout = WATCHDOG_NOWAYOUT;
#ifdef CONFIG_HPWDT_NMI_DECODING
static unsigned int allow_kdump = 1;
#endif
static char expect_release;
static unsigned long hpwdt_is_open;
static void __iomem *pci_mem_addr; /* the PCI-memory address */
static unsigned long __iomem *hpwdt_nmistat;
static unsigned long __iomem *hpwdt_timer_reg;
static unsigned long __iomem *hpwdt_timer_con;
static const struct pci_device_id hpwdt_devices[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) }, /* iLO2 */
{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) }, /* iLO3 */
{0}, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, hpwdt_devices);
/*
* Watchdog operations
*/
static void hpwdt_start(void)
{
reload = SECS_TO_TICKS(soft_margin);
iowrite16(reload, hpwdt_timer_reg);
iowrite8(0x85, hpwdt_timer_con);
}
static void hpwdt_stop(void)
{
unsigned long data;
data = ioread8(hpwdt_timer_con);
data &= 0xFE;
iowrite8(data, hpwdt_timer_con);
}
static void hpwdt_ping(void)
{
iowrite16(reload, hpwdt_timer_reg);
}
static int hpwdt_change_timer(int new_margin)
{
if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
pr_warn("New value passed in is invalid: %d seconds\n",
new_margin);
return -EINVAL;
}
soft_margin = new_margin;
pr_debug("New timer passed in is %d seconds\n", new_margin);
reload = SECS_TO_TICKS(soft_margin);
return 0;
}
static int hpwdt_time_left(void)
{
return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
}
#ifdef CONFIG_HPWDT_NMI_DECODING
static int hpwdt_my_nmi(void)
{
return ioread8(hpwdt_nmistat) & 0x6;
}
/*
* NMI Handler
*/
static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
{
if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
return NMI_DONE;
if (allow_kdump)
hpwdt_stop();
nmi_panic(regs, "An NMI occurred. Depending on your system the reason "
"for the NMI is logged in any one of the following "
"resources:\n"
"1. Integrated Management Log (IML)\n"
"2. OA Syslog\n"
"3. OA Forward Progress Log\n"
"4. iLO Event Log");
return NMI_HANDLED;
}
#endif /* CONFIG_HPWDT_NMI_DECODING */
/*
* /dev/watchdog handling
*/
static int hpwdt_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &hpwdt_is_open))
return -EBUSY;
/* Start the watchdog */
hpwdt_start();
hpwdt_ping();
return nonseekable_open(inode, file);
}
static int hpwdt_release(struct inode *inode, struct file *file)
{
/* Stop the watchdog */
if (expect_release == 42) {
hpwdt_stop();
} else {
pr_crit("Unexpected close, not stopping watchdog!\n");
hpwdt_ping();
}
expect_release = 0;
/* /dev/watchdog is being closed, make sure it can be re-opened */
clear_bit(0, &hpwdt_is_open);
return 0;
}
static ssize_t hpwdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (len) {
if (!nowayout) {
size_t i;
/* note: just in case someone wrote the magic character
* five months ago... */
expect_release = 0;
/* scan to see whether or not we got the magic char. */
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
expect_release = 42;
}
}
/* someone wrote to us, we should reload the timer */
hpwdt_ping();
}
return len;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "HPE iLO2+ HW Watchdog Timer",
};
static long hpwdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_margin, options;
int ret = -ENOTTY;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = 0;
if (copy_to_user(argp, &ident, sizeof(ident)))
ret = -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, p);
break;
case WDIOC_KEEPALIVE:
hpwdt_ping();
ret = 0;
break;
case WDIOC_SETOPTIONS:
ret = get_user(options, p);
if (ret)
break;
if (options & WDIOS_DISABLECARD)
hpwdt_stop();
if (options & WDIOS_ENABLECARD) {
hpwdt_start();
hpwdt_ping();
}
break;
case WDIOC_SETTIMEOUT:
ret = get_user(new_margin, p);
if (ret)
break;
ret = hpwdt_change_timer(new_margin);
if (ret)
break;
hpwdt_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
ret = put_user(soft_margin, p);
break;
case WDIOC_GETTIMELEFT:
ret = put_user(hpwdt_time_left(), p);
break;
}
return ret;
}
/*
* Kernel interfaces
*/
static const struct file_operations hpwdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = hpwdt_write,
.unlocked_ioctl = hpwdt_ioctl,
.open = hpwdt_open,
.release = hpwdt_release,
};
static struct miscdevice hpwdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &hpwdt_fops,
};
/*
* Init & Exit
*/
static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
{
#ifdef CONFIG_HPWDT_NMI_DECODING
int retval;
/*
* Only one function can register for NMI_UNKNOWN
*/
retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
if (retval)
goto error;
retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
if (retval)
goto error1;
retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
if (retval)
goto error2;
dev_info(&dev->dev,
"HPE Watchdog Timer Driver: NMI decoding initialized"
", allow kernel dump: %s (default = 1/ON)\n",
(allow_kdump == 0) ? "OFF" : "ON");
return 0;
error2:
unregister_nmi_handler(NMI_SERR, "hpwdt");
error1:
unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
error:
dev_warn(&dev->dev,
"Unable to register a die notifier (err=%d).\n",
retval);
return retval;
#endif /* CONFIG_HPWDT_NMI_DECODING */
return 0;
}
static void hpwdt_exit_nmi_decoding(void)
{
#ifdef CONFIG_HPWDT_NMI_DECODING
unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
unregister_nmi_handler(NMI_SERR, "hpwdt");
unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
#endif
}
static int hpwdt_init_one(struct pci_dev *dev,
const struct pci_device_id *ent)
{
int retval;
/*
* First let's find out if we are on an iLO2+ server. We will
* not run on a legacy ASM box.
* So we only support the G5 ProLiant servers and higher.
*/
if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
dev_warn(&dev->dev,
"This server does not have an iLO2+ ASIC.\n");
return -ENODEV;
}
/*
* Ignore all auxilary iLO devices with the following PCI ID
*/
if (dev->subsystem_vendor == PCI_VENDOR_ID_HP &&
dev->subsystem_device == 0x1979)
return -ENODEV;
if (pci_enable_device(dev)) {
dev_warn(&dev->dev,
"Not possible to enable PCI Device: 0x%x:0x%x.\n",
ent->vendor, ent->device);
return -ENODEV;
}
pci_mem_addr = pci_iomap(dev, 1, 0x80);
if (!pci_mem_addr) {
dev_warn(&dev->dev,
"Unable to detect the iLO2+ server memory.\n");
retval = -ENOMEM;
goto error_pci_iomap;
}
hpwdt_nmistat = pci_mem_addr + 0x6e;
hpwdt_timer_reg = pci_mem_addr + 0x70;
hpwdt_timer_con = pci_mem_addr + 0x72;
/* Make sure that timer is disabled until /dev/watchdog is opened */
hpwdt_stop();
/* Make sure that we have a valid soft_margin */
if (hpwdt_change_timer(soft_margin))
hpwdt_change_timer(DEFAULT_MARGIN);
/* Initialize NMI Decoding functionality */
retval = hpwdt_init_nmi_decoding(dev);
if (retval != 0)
goto error_init_nmi_decoding;
retval = misc_register(&hpwdt_miscdev);
if (retval < 0) {
dev_warn(&dev->dev,
"Unable to register miscdev on minor=%d (err=%d).\n",
WATCHDOG_MINOR, retval);
goto error_misc_register;
}
dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s"
", timer margin: %d seconds (nowayout=%d).\n",
HPWDT_VERSION, soft_margin, nowayout);
return 0;
error_misc_register:
hpwdt_exit_nmi_decoding();
error_init_nmi_decoding:
pci_iounmap(dev, pci_mem_addr);
error_pci_iomap:
pci_disable_device(dev);
return retval;
}
static void hpwdt_exit(struct pci_dev *dev)
{
if (!nowayout)
hpwdt_stop();
misc_deregister(&hpwdt_miscdev);
hpwdt_exit_nmi_decoding();
pci_iounmap(dev, pci_mem_addr);
pci_disable_device(dev);
}
static struct pci_driver hpwdt_driver = {
.name = "hpwdt",
.id_table = hpwdt_devices,
.probe = hpwdt_init_one,
.remove = hpwdt_exit,
};
MODULE_AUTHOR("Tom Mingarelli");
MODULE_DESCRIPTION("hp watchdog driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(HPWDT_VERSION);
module_param(soft_margin, int, 0);
MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
#ifdef CONFIG_HPWDT_NMI_DECODING
module_param(allow_kdump, int, 0);
MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
#endif /* CONFIG_HPWDT_NMI_DECODING */
module_pci_driver(hpwdt_driver);