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cabe17d017
If the BIOS default timeout for the watchdog is too small userspace may not have enough time to configure new timeout after opening the device before the system is already reset. For this reason program default timeout of 30 seconds in the driver probe and allow userspace to change this from command line or through module parameter (wdat_wdt.timeout). Reported-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
550 lines
13 KiB
C
550 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* ACPI Hardware Watchdog (WDAT) driver.
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*
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* Copyright (C) 2016, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*/
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#include <linux/acpi.h>
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#include <linux/ioport.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/watchdog.h>
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#define MAX_WDAT_ACTIONS ACPI_WDAT_ACTION_RESERVED
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/**
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* struct wdat_instruction - Single ACPI WDAT instruction
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* @entry: Copy of the ACPI table instruction
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* @reg: Register the instruction is accessing
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* @node: Next instruction in action sequence
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*/
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struct wdat_instruction {
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struct acpi_wdat_entry entry;
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void __iomem *reg;
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struct list_head node;
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};
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/**
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* struct wdat_wdt - ACPI WDAT watchdog device
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* @pdev: Parent platform device
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* @wdd: Watchdog core device
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* @period: How long is one watchdog period in ms
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* @stopped_in_sleep: Is this watchdog stopped by the firmware in S1-S5
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* @stopped: Was the watchdog stopped by the driver in suspend
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* @actions: An array of instruction lists indexed by an action number from
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* the WDAT table. There can be %NULL entries for not implemented
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* actions.
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*/
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struct wdat_wdt {
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struct platform_device *pdev;
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struct watchdog_device wdd;
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unsigned int period;
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bool stopped_in_sleep;
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bool stopped;
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struct list_head *instructions[MAX_WDAT_ACTIONS];
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};
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#define to_wdat_wdt(wdd) container_of(wdd, struct wdat_wdt, wdd)
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static bool nowayout = WATCHDOG_NOWAYOUT;
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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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#define WDAT_DEFAULT_TIMEOUT 30
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static int timeout = WDAT_DEFAULT_TIMEOUT;
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
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__MODULE_STRING(WDAT_DEFAULT_TIMEOUT) ")");
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static int wdat_wdt_read(struct wdat_wdt *wdat,
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const struct wdat_instruction *instr, u32 *value)
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{
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const struct acpi_generic_address *gas = &instr->entry.register_region;
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switch (gas->access_width) {
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case 1:
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*value = ioread8(instr->reg);
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break;
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case 2:
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*value = ioread16(instr->reg);
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break;
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case 3:
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*value = ioread32(instr->reg);
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break;
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default:
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return -EINVAL;
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}
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dev_dbg(&wdat->pdev->dev, "Read %#x from 0x%08llx\n", *value,
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gas->address);
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return 0;
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}
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static int wdat_wdt_write(struct wdat_wdt *wdat,
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const struct wdat_instruction *instr, u32 value)
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{
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const struct acpi_generic_address *gas = &instr->entry.register_region;
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switch (gas->access_width) {
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case 1:
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iowrite8((u8)value, instr->reg);
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break;
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case 2:
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iowrite16((u16)value, instr->reg);
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break;
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case 3:
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iowrite32(value, instr->reg);
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break;
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default:
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return -EINVAL;
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}
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dev_dbg(&wdat->pdev->dev, "Wrote %#x to 0x%08llx\n", value,
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gas->address);
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return 0;
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}
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static int wdat_wdt_run_action(struct wdat_wdt *wdat, unsigned int action,
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u32 param, u32 *retval)
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{
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struct wdat_instruction *instr;
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if (action >= ARRAY_SIZE(wdat->instructions))
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return -EINVAL;
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if (!wdat->instructions[action])
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return -EOPNOTSUPP;
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dev_dbg(&wdat->pdev->dev, "Running action %#x\n", action);
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/* Run each instruction sequentially */
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list_for_each_entry(instr, wdat->instructions[action], node) {
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const struct acpi_wdat_entry *entry = &instr->entry;
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const struct acpi_generic_address *gas;
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u32 flags, value, mask, x, y;
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bool preserve;
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int ret;
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gas = &entry->register_region;
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preserve = entry->instruction & ACPI_WDAT_PRESERVE_REGISTER;
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flags = entry->instruction & ~ACPI_WDAT_PRESERVE_REGISTER;
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value = entry->value;
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mask = entry->mask;
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switch (flags) {
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case ACPI_WDAT_READ_VALUE:
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ret = wdat_wdt_read(wdat, instr, &x);
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if (ret)
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return ret;
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x >>= gas->bit_offset;
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x &= mask;
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if (retval)
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*retval = x == value;
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break;
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case ACPI_WDAT_READ_COUNTDOWN:
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ret = wdat_wdt_read(wdat, instr, &x);
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if (ret)
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return ret;
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x >>= gas->bit_offset;
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x &= mask;
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if (retval)
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*retval = x;
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break;
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case ACPI_WDAT_WRITE_VALUE:
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x = value & mask;
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x <<= gas->bit_offset;
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if (preserve) {
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ret = wdat_wdt_read(wdat, instr, &y);
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if (ret)
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return ret;
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y = y & ~(mask << gas->bit_offset);
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x |= y;
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}
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ret = wdat_wdt_write(wdat, instr, x);
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if (ret)
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return ret;
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break;
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case ACPI_WDAT_WRITE_COUNTDOWN:
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x = param;
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x &= mask;
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x <<= gas->bit_offset;
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if (preserve) {
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ret = wdat_wdt_read(wdat, instr, &y);
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if (ret)
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return ret;
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y = y & ~(mask << gas->bit_offset);
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x |= y;
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}
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ret = wdat_wdt_write(wdat, instr, x);
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if (ret)
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return ret;
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break;
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default:
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dev_err(&wdat->pdev->dev, "Unknown instruction: %u\n",
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flags);
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return -EINVAL;
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}
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}
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return 0;
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}
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static int wdat_wdt_enable_reboot(struct wdat_wdt *wdat)
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{
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int ret;
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/*
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* WDAT specification says that the watchdog is required to reboot
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* the system when it fires. However, it also states that it is
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* recommeded to make it configurable through hardware register. We
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* enable reboot now if it is configurable, just in case.
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*/
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ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_REBOOT, 0, NULL);
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if (ret && ret != -EOPNOTSUPP) {
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dev_err(&wdat->pdev->dev,
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"Failed to enable reboot when watchdog triggers\n");
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return ret;
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}
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return 0;
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}
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static void wdat_wdt_boot_status(struct wdat_wdt *wdat)
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{
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u32 boot_status = 0;
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int ret;
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ret = wdat_wdt_run_action(wdat, ACPI_WDAT_GET_STATUS, 0, &boot_status);
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if (ret && ret != -EOPNOTSUPP) {
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dev_err(&wdat->pdev->dev, "Failed to read boot status\n");
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return;
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}
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if (boot_status)
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wdat->wdd.bootstatus = WDIOF_CARDRESET;
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/* Clear the boot status in case BIOS did not do it */
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ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_STATUS, 0, NULL);
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if (ret && ret != -EOPNOTSUPP)
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dev_err(&wdat->pdev->dev, "Failed to clear boot status\n");
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}
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static void wdat_wdt_set_running(struct wdat_wdt *wdat)
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{
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u32 running = 0;
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int ret;
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ret = wdat_wdt_run_action(wdat, ACPI_WDAT_GET_RUNNING_STATE, 0,
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&running);
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if (ret && ret != -EOPNOTSUPP)
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dev_err(&wdat->pdev->dev, "Failed to read running state\n");
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if (running)
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set_bit(WDOG_HW_RUNNING, &wdat->wdd.status);
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}
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static int wdat_wdt_start(struct watchdog_device *wdd)
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{
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return wdat_wdt_run_action(to_wdat_wdt(wdd),
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ACPI_WDAT_SET_RUNNING_STATE, 0, NULL);
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}
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static int wdat_wdt_stop(struct watchdog_device *wdd)
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{
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return wdat_wdt_run_action(to_wdat_wdt(wdd),
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ACPI_WDAT_SET_STOPPED_STATE, 0, NULL);
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}
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static int wdat_wdt_ping(struct watchdog_device *wdd)
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{
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return wdat_wdt_run_action(to_wdat_wdt(wdd), ACPI_WDAT_RESET, 0, NULL);
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}
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static int wdat_wdt_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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struct wdat_wdt *wdat = to_wdat_wdt(wdd);
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unsigned int periods;
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int ret;
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periods = timeout * 1000 / wdat->period;
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ret = wdat_wdt_run_action(wdat, ACPI_WDAT_SET_COUNTDOWN, periods, NULL);
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if (!ret)
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wdd->timeout = timeout;
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return ret;
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}
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static unsigned int wdat_wdt_get_timeleft(struct watchdog_device *wdd)
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{
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struct wdat_wdt *wdat = to_wdat_wdt(wdd);
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u32 periods = 0;
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wdat_wdt_run_action(wdat, ACPI_WDAT_GET_CURRENT_COUNTDOWN, 0, &periods);
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return periods * wdat->period / 1000;
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}
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static const struct watchdog_info wdat_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.firmware_version = 0,
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.identity = "wdat_wdt",
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};
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static const struct watchdog_ops wdat_wdt_ops = {
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.owner = THIS_MODULE,
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.start = wdat_wdt_start,
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.stop = wdat_wdt_stop,
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.ping = wdat_wdt_ping,
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.set_timeout = wdat_wdt_set_timeout,
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.get_timeleft = wdat_wdt_get_timeleft,
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};
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static int wdat_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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const struct acpi_wdat_entry *entries;
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const struct acpi_table_wdat *tbl;
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struct wdat_wdt *wdat;
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struct resource *res;
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void __iomem **regs;
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acpi_status status;
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int i, ret;
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status = acpi_get_table(ACPI_SIG_WDAT, 0,
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(struct acpi_table_header **)&tbl);
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if (ACPI_FAILURE(status))
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return -ENODEV;
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wdat = devm_kzalloc(dev, sizeof(*wdat), GFP_KERNEL);
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if (!wdat)
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return -ENOMEM;
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regs = devm_kcalloc(dev, pdev->num_resources, sizeof(*regs),
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GFP_KERNEL);
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if (!regs)
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return -ENOMEM;
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/* WDAT specification wants to have >= 1ms period */
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if (tbl->timer_period < 1)
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return -EINVAL;
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if (tbl->min_count > tbl->max_count)
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return -EINVAL;
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wdat->period = tbl->timer_period;
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wdat->wdd.min_hw_heartbeat_ms = wdat->period * tbl->min_count;
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wdat->wdd.max_hw_heartbeat_ms = wdat->period * tbl->max_count;
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wdat->stopped_in_sleep = tbl->flags & ACPI_WDAT_STOPPED;
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wdat->wdd.info = &wdat_wdt_info;
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wdat->wdd.ops = &wdat_wdt_ops;
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wdat->pdev = pdev;
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/* Request and map all resources */
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for (i = 0; i < pdev->num_resources; i++) {
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void __iomem *reg;
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res = &pdev->resource[i];
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if (resource_type(res) == IORESOURCE_MEM) {
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reg = devm_ioremap_resource(dev, res);
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if (IS_ERR(reg))
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return PTR_ERR(reg);
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} else if (resource_type(res) == IORESOURCE_IO) {
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reg = devm_ioport_map(dev, res->start, 1);
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if (!reg)
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return -ENOMEM;
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} else {
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dev_err(dev, "Unsupported resource\n");
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return -EINVAL;
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}
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regs[i] = reg;
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}
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entries = (struct acpi_wdat_entry *)(tbl + 1);
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for (i = 0; i < tbl->entries; i++) {
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const struct acpi_generic_address *gas;
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struct wdat_instruction *instr;
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struct list_head *instructions;
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unsigned int action;
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struct resource r;
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int j;
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action = entries[i].action;
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if (action >= MAX_WDAT_ACTIONS) {
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dev_dbg(dev, "Skipping unknown action: %u\n", action);
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continue;
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}
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instr = devm_kzalloc(dev, sizeof(*instr), GFP_KERNEL);
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if (!instr)
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return -ENOMEM;
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INIT_LIST_HEAD(&instr->node);
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instr->entry = entries[i];
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gas = &entries[i].register_region;
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memset(&r, 0, sizeof(r));
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r.start = gas->address;
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r.end = r.start + ACPI_ACCESS_BYTE_WIDTH(gas->access_width) - 1;
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if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
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r.flags = IORESOURCE_MEM;
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} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
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r.flags = IORESOURCE_IO;
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} else {
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dev_dbg(dev, "Unsupported address space: %d\n",
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gas->space_id);
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continue;
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}
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/* Find the matching resource */
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for (j = 0; j < pdev->num_resources; j++) {
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res = &pdev->resource[j];
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if (resource_contains(res, &r)) {
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instr->reg = regs[j] + r.start - res->start;
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break;
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}
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}
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if (!instr->reg) {
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dev_err(dev, "I/O resource not found\n");
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return -EINVAL;
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}
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instructions = wdat->instructions[action];
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if (!instructions) {
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instructions = devm_kzalloc(dev,
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sizeof(*instructions),
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GFP_KERNEL);
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if (!instructions)
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return -ENOMEM;
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INIT_LIST_HEAD(instructions);
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wdat->instructions[action] = instructions;
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}
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list_add_tail(&instr->node, instructions);
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}
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wdat_wdt_boot_status(wdat);
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wdat_wdt_set_running(wdat);
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ret = wdat_wdt_enable_reboot(wdat);
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if (ret)
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return ret;
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platform_set_drvdata(pdev, wdat);
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/*
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* Set initial timeout so that userspace has time to configure the
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* watchdog properly after it has opened the device. In some cases
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* the BIOS default is too short and causes immediate reboot.
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*/
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if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms ||
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timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) {
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dev_warn(dev, "Invalid timeout %d given, using %d\n",
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timeout, WDAT_DEFAULT_TIMEOUT);
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timeout = WDAT_DEFAULT_TIMEOUT;
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}
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ret = wdat_wdt_set_timeout(&wdat->wdd, timeout);
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if (ret)
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return ret;
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watchdog_set_nowayout(&wdat->wdd, nowayout);
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return devm_watchdog_register_device(dev, &wdat->wdd);
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}
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#ifdef CONFIG_PM_SLEEP
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static int wdat_wdt_suspend_noirq(struct device *dev)
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{
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struct wdat_wdt *wdat = dev_get_drvdata(dev);
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int ret;
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if (!watchdog_active(&wdat->wdd))
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return 0;
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/*
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* We need to stop the watchdog if firmare is not doing it or if we
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* are going suspend to idle (where firmware is not involved). If
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* firmware is stopping the watchdog we kick it here one more time
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* to give it some time.
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*/
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wdat->stopped = false;
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if (acpi_target_system_state() == ACPI_STATE_S0 ||
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!wdat->stopped_in_sleep) {
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ret = wdat_wdt_stop(&wdat->wdd);
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if (!ret)
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wdat->stopped = true;
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} else {
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ret = wdat_wdt_ping(&wdat->wdd);
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}
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return ret;
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}
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static int wdat_wdt_resume_noirq(struct device *dev)
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{
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struct wdat_wdt *wdat = dev_get_drvdata(dev);
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int ret;
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if (!watchdog_active(&wdat->wdd))
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return 0;
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if (!wdat->stopped) {
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/*
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* Looks like the boot firmware reinitializes the watchdog
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* before it hands off to the OS on resume from sleep so we
|
|
* stop and reprogram the watchdog here.
|
|
*/
|
|
ret = wdat_wdt_stop(&wdat->wdd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wdat_wdt_set_timeout(&wdat->wdd, wdat->wdd.timeout);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wdat_wdt_enable_reboot(wdat);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = wdat_wdt_ping(&wdat->wdd);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return wdat_wdt_start(&wdat->wdd);
|
|
}
|
|
#endif
|
|
|
|
static const struct dev_pm_ops wdat_wdt_pm_ops = {
|
|
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(wdat_wdt_suspend_noirq,
|
|
wdat_wdt_resume_noirq)
|
|
};
|
|
|
|
static struct platform_driver wdat_wdt_driver = {
|
|
.probe = wdat_wdt_probe,
|
|
.driver = {
|
|
.name = "wdat_wdt",
|
|
.pm = &wdat_wdt_pm_ops,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(wdat_wdt_driver);
|
|
|
|
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
|
|
MODULE_DESCRIPTION("ACPI Hardware Watchdog (WDAT) driver");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("platform:wdat_wdt");
|