2b3d89b402
Gen8 and prior Proliant systems supported the "CRU" interface to firmware. This interfaces allows linux to "call back" into firmware to source the cause of an NMI. This feature isn't fully utilized as the actual source of the NMI isn't printed, the driver only indicates that the source couldn't be determined when the call fails. With the advent of Gen9, iCRU replaces the CRU. The call back feature is no longer available in firmware. To be compatible and not attempt to call back into firmware on system not supporting CRU, the SMBIOS table is consulted to determine if it is safe to make the call back or not. This results in about half of the driver code being devoted to either making CRU calls or determing if it is safe to make CRU calls. As noted, the driver isn't really using the results of the CRU calls. Furthermore, as a consequence of the Spectre security issue, the BIOS/EFI calls are being wrapped into Spectre-disabling section. Removing the call back in hpwdt_pretimeout assists in this effort. As the CRU sourcing of the NMI isn't required for handling the NMI and there are security concerns with making the call back, remove the legacy (pre Gen9) NMI sourcing and the DMI code to determine if the system had the CRU interface. Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
445 lines
9.9 KiB
C
445 lines
9.9 KiB
C
/*
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* HPE WatchDog Driver
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* based on
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*
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* SoftDog 0.05: A Software Watchdog Device
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*
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* (c) Copyright 2015 Hewlett Packard Enterprise Development LP
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* Thomas Mingarelli <thomas.mingarelli@hpe.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/io.h>
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#include <linux/bitops.h>
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#include <linux/kernel.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/pci.h>
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#include <linux/pci_ids.h>
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#include <linux/types.h>
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#include <linux/uaccess.h>
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#include <linux/watchdog.h>
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#include <asm/nmi.h>
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#define HPWDT_VERSION "1.4.0"
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#define SECS_TO_TICKS(secs) ((secs) * 1000 / 128)
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#define TICKS_TO_SECS(ticks) ((ticks) * 128 / 1000)
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#define HPWDT_MAX_TIMER TICKS_TO_SECS(65535)
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#define DEFAULT_MARGIN 30
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static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
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static unsigned int reload; /* the computed soft_margin */
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static bool nowayout = WATCHDOG_NOWAYOUT;
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#ifdef CONFIG_HPWDT_NMI_DECODING
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static unsigned int allow_kdump = 1;
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#endif
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static char expect_release;
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static unsigned long hpwdt_is_open;
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static void __iomem *pci_mem_addr; /* the PCI-memory address */
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static unsigned long __iomem *hpwdt_nmistat;
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static unsigned long __iomem *hpwdt_timer_reg;
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static unsigned long __iomem *hpwdt_timer_con;
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static const struct pci_device_id hpwdt_devices[] = {
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{ PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) }, /* iLO2 */
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{ PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) }, /* iLO3 */
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{0}, /* terminate list */
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};
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MODULE_DEVICE_TABLE(pci, hpwdt_devices);
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/*
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* Watchdog operations
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*/
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static void hpwdt_start(void)
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{
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reload = SECS_TO_TICKS(soft_margin);
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iowrite16(reload, hpwdt_timer_reg);
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iowrite8(0x85, hpwdt_timer_con);
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}
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static void hpwdt_stop(void)
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{
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unsigned long data;
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data = ioread8(hpwdt_timer_con);
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data &= 0xFE;
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iowrite8(data, hpwdt_timer_con);
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}
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static void hpwdt_ping(void)
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{
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iowrite16(reload, hpwdt_timer_reg);
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}
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static int hpwdt_change_timer(int new_margin)
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{
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if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) {
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pr_warn("New value passed in is invalid: %d seconds\n",
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new_margin);
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return -EINVAL;
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}
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soft_margin = new_margin;
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pr_debug("New timer passed in is %d seconds\n", new_margin);
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reload = SECS_TO_TICKS(soft_margin);
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return 0;
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}
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static int hpwdt_time_left(void)
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{
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return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
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}
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#ifdef CONFIG_HPWDT_NMI_DECODING
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static int hpwdt_my_nmi(void)
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{
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return ioread8(hpwdt_nmistat) & 0x6;
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}
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/*
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* NMI Handler
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*/
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static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
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{
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if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
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return NMI_DONE;
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if (allow_kdump)
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hpwdt_stop();
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nmi_panic(regs, "An NMI occurred. Depending on your system the reason "
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"for the NMI is logged in any one of the following "
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"resources:\n"
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"1. Integrated Management Log (IML)\n"
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"2. OA Syslog\n"
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"3. OA Forward Progress Log\n"
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"4. iLO Event Log");
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return NMI_HANDLED;
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}
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#endif /* CONFIG_HPWDT_NMI_DECODING */
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/*
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* /dev/watchdog handling
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*/
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static int hpwdt_open(struct inode *inode, struct file *file)
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{
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/* /dev/watchdog can only be opened once */
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if (test_and_set_bit(0, &hpwdt_is_open))
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return -EBUSY;
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/* Start the watchdog */
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hpwdt_start();
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hpwdt_ping();
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return nonseekable_open(inode, file);
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}
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static int hpwdt_release(struct inode *inode, struct file *file)
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{
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/* Stop the watchdog */
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if (expect_release == 42) {
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hpwdt_stop();
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} else {
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pr_crit("Unexpected close, not stopping watchdog!\n");
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hpwdt_ping();
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}
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expect_release = 0;
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/* /dev/watchdog is being closed, make sure it can be re-opened */
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clear_bit(0, &hpwdt_is_open);
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return 0;
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}
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static ssize_t hpwdt_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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/* See if we got the magic character 'V' and reload the timer */
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if (len) {
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if (!nowayout) {
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size_t i;
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/* note: just in case someone wrote the magic character
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* five months ago... */
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expect_release = 0;
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/* scan to see whether or not we got the magic char. */
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for (i = 0; i != len; i++) {
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char c;
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if (get_user(c, data + i))
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return -EFAULT;
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if (c == 'V')
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expect_release = 42;
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}
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}
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/* someone wrote to us, we should reload the timer */
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hpwdt_ping();
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}
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return len;
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}
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static const struct watchdog_info ident = {
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.options = WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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.identity = "HPE iLO2+ HW Watchdog Timer",
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};
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static long hpwdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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int new_margin, options;
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int ret = -ENOTTY;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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ret = 0;
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if (copy_to_user(argp, &ident, sizeof(ident)))
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ret = -EFAULT;
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break;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(0, p);
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break;
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case WDIOC_KEEPALIVE:
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hpwdt_ping();
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ret = 0;
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break;
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case WDIOC_SETOPTIONS:
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ret = get_user(options, p);
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if (ret)
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break;
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if (options & WDIOS_DISABLECARD)
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hpwdt_stop();
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if (options & WDIOS_ENABLECARD) {
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hpwdt_start();
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hpwdt_ping();
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}
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(new_margin, p);
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if (ret)
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break;
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ret = hpwdt_change_timer(new_margin);
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if (ret)
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break;
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hpwdt_ping();
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/* Fall */
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case WDIOC_GETTIMEOUT:
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ret = put_user(soft_margin, p);
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break;
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case WDIOC_GETTIMELEFT:
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ret = put_user(hpwdt_time_left(), p);
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break;
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}
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return ret;
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}
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/*
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* Kernel interfaces
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*/
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static const struct file_operations hpwdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = hpwdt_write,
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.unlocked_ioctl = hpwdt_ioctl,
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.open = hpwdt_open,
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.release = hpwdt_release,
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};
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static struct miscdevice hpwdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &hpwdt_fops,
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};
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/*
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* Init & Exit
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*/
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static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
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{
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#ifdef CONFIG_HPWDT_NMI_DECODING
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int retval;
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/*
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* Only one function can register for NMI_UNKNOWN
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*/
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retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
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if (retval)
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goto error;
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retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
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if (retval)
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goto error1;
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retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
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if (retval)
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goto error2;
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dev_info(&dev->dev,
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"HPE Watchdog Timer Driver: NMI decoding initialized"
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", allow kernel dump: %s (default = 1/ON)\n",
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(allow_kdump == 0) ? "OFF" : "ON");
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return 0;
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error2:
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unregister_nmi_handler(NMI_SERR, "hpwdt");
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error1:
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unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
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error:
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dev_warn(&dev->dev,
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"Unable to register a die notifier (err=%d).\n",
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retval);
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return retval;
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#endif /* CONFIG_HPWDT_NMI_DECODING */
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return 0;
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}
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static void hpwdt_exit_nmi_decoding(void)
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{
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#ifdef CONFIG_HPWDT_NMI_DECODING
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unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
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unregister_nmi_handler(NMI_SERR, "hpwdt");
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unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
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#endif
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}
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static int hpwdt_init_one(struct pci_dev *dev,
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const struct pci_device_id *ent)
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{
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int retval;
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/*
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* First let's find out if we are on an iLO2+ server. We will
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* not run on a legacy ASM box.
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* So we only support the G5 ProLiant servers and higher.
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*/
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if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
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dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
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dev_warn(&dev->dev,
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"This server does not have an iLO2+ ASIC.\n");
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return -ENODEV;
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}
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/*
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* Ignore all auxilary iLO devices with the following PCI ID
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*/
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if (dev->subsystem_vendor == PCI_VENDOR_ID_HP &&
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dev->subsystem_device == 0x1979)
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return -ENODEV;
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if (pci_enable_device(dev)) {
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dev_warn(&dev->dev,
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"Not possible to enable PCI Device: 0x%x:0x%x.\n",
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ent->vendor, ent->device);
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return -ENODEV;
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}
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pci_mem_addr = pci_iomap(dev, 1, 0x80);
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if (!pci_mem_addr) {
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dev_warn(&dev->dev,
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"Unable to detect the iLO2+ server memory.\n");
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retval = -ENOMEM;
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goto error_pci_iomap;
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}
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hpwdt_nmistat = pci_mem_addr + 0x6e;
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hpwdt_timer_reg = pci_mem_addr + 0x70;
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hpwdt_timer_con = pci_mem_addr + 0x72;
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/* Make sure that timer is disabled until /dev/watchdog is opened */
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hpwdt_stop();
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/* Make sure that we have a valid soft_margin */
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if (hpwdt_change_timer(soft_margin))
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hpwdt_change_timer(DEFAULT_MARGIN);
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/* Initialize NMI Decoding functionality */
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retval = hpwdt_init_nmi_decoding(dev);
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if (retval != 0)
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goto error_init_nmi_decoding;
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retval = misc_register(&hpwdt_miscdev);
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if (retval < 0) {
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dev_warn(&dev->dev,
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"Unable to register miscdev on minor=%d (err=%d).\n",
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WATCHDOG_MINOR, retval);
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goto error_misc_register;
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}
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dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s"
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", timer margin: %d seconds (nowayout=%d).\n",
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HPWDT_VERSION, soft_margin, nowayout);
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return 0;
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error_misc_register:
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hpwdt_exit_nmi_decoding();
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error_init_nmi_decoding:
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pci_iounmap(dev, pci_mem_addr);
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error_pci_iomap:
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pci_disable_device(dev);
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return retval;
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}
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static void hpwdt_exit(struct pci_dev *dev)
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{
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if (!nowayout)
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hpwdt_stop();
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misc_deregister(&hpwdt_miscdev);
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hpwdt_exit_nmi_decoding();
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pci_iounmap(dev, pci_mem_addr);
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pci_disable_device(dev);
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}
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static struct pci_driver hpwdt_driver = {
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.name = "hpwdt",
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.id_table = hpwdt_devices,
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.probe = hpwdt_init_one,
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.remove = hpwdt_exit,
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};
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MODULE_AUTHOR("Tom Mingarelli");
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MODULE_DESCRIPTION("hp watchdog driver");
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MODULE_LICENSE("GPL");
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MODULE_VERSION(HPWDT_VERSION);
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module_param(soft_margin, int, 0);
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MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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#ifdef CONFIG_HPWDT_NMI_DECODING
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module_param(allow_kdump, int, 0);
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MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
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#endif /* CONFIG_HPWDT_NMI_DECODING */
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module_pci_driver(hpwdt_driver);
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