|  | /* | 
|  | *	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); |