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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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b6dfb2477f
All watchdog drivers implement the same set of ioctl commands, and fortunately all of them are compatible between 32-bit and 64-bit architectures. Modern drivers always go through drivers/watchdog/wdt.c as an abstraction layer, but older ones implement their own file_operations on a character device for this. Move the handling from fs/compat_ioctl.c into the individual drivers. Note that most of the legacy drivers will never be used on 64-bit hardware, because they are for an old 32-bit SoC implementation, but doing them all at once is safer than trying to guess which ones do or do not need the compat_ioctl handling. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
629 lines
15 KiB
C
629 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* FIXME: add wdrtas_get_status and wdrtas_get_boot_status as soon as
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* RTAS calls are available
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*/
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/*
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* RTAS watchdog driver
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*
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* (C) Copyright IBM Corp. 2005
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* device driver to exploit watchdog RTAS functions
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*
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* Authors : Utz Bacher <utz.bacher@de.ibm.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/fs.h>
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#include <linux/init.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/notifier.h>
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#include <linux/reboot.h>
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#include <linux/types.h>
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#include <linux/watchdog.h>
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#include <linux/uaccess.h>
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#include <asm/rtas.h>
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#define WDRTAS_MAGIC_CHAR 42
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#define WDRTAS_SUPPORTED_MASK (WDIOF_SETTIMEOUT | \
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WDIOF_MAGICCLOSE)
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MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com>");
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MODULE_DESCRIPTION("RTAS watchdog driver");
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MODULE_LICENSE("GPL");
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static bool wdrtas_nowayout = WATCHDOG_NOWAYOUT;
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static atomic_t wdrtas_miscdev_open = ATOMIC_INIT(0);
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static char wdrtas_expect_close;
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static int wdrtas_interval;
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#define WDRTAS_THERMAL_SENSOR 3
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static int wdrtas_token_get_sensor_state;
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#define WDRTAS_SURVEILLANCE_IND 9000
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static int wdrtas_token_set_indicator;
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#define WDRTAS_SP_SPI 28
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static int wdrtas_token_get_sp;
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static int wdrtas_token_event_scan;
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#define WDRTAS_DEFAULT_INTERVAL 300
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#define WDRTAS_LOGBUFFER_LEN 128
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static char wdrtas_logbuffer[WDRTAS_LOGBUFFER_LEN];
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/*** watchdog access functions */
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/**
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* wdrtas_set_interval - sets the watchdog interval
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* @interval: new interval
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*
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* returns 0 on success, <0 on failures
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*
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* wdrtas_set_interval sets the watchdog keepalive interval by calling the
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* RTAS function set-indicator (surveillance). The unit of interval is
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* seconds.
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*/
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static int wdrtas_set_interval(int interval)
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{
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long result;
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static int print_msg = 10;
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/* rtas uses minutes */
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interval = (interval + 59) / 60;
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result = rtas_call(wdrtas_token_set_indicator, 3, 1, NULL,
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WDRTAS_SURVEILLANCE_IND, 0, interval);
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if (result < 0 && print_msg) {
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pr_err("setting the watchdog to %i timeout failed: %li\n",
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interval, result);
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print_msg--;
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}
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return result;
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}
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#define WDRTAS_SP_SPI_LEN 4
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/**
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* wdrtas_get_interval - returns the current watchdog interval
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* @fallback_value: value (in seconds) to use, if the RTAS call fails
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*
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* returns the interval
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*
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* wdrtas_get_interval returns the current watchdog keepalive interval
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* as reported by the RTAS function ibm,get-system-parameter. The unit
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* of the return value is seconds.
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*/
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static int wdrtas_get_interval(int fallback_value)
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{
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long result;
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char value[WDRTAS_SP_SPI_LEN];
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spin_lock(&rtas_data_buf_lock);
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memset(rtas_data_buf, 0, WDRTAS_SP_SPI_LEN);
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result = rtas_call(wdrtas_token_get_sp, 3, 1, NULL,
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WDRTAS_SP_SPI, __pa(rtas_data_buf),
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WDRTAS_SP_SPI_LEN);
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memcpy(value, rtas_data_buf, WDRTAS_SP_SPI_LEN);
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spin_unlock(&rtas_data_buf_lock);
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if (value[0] != 0 || value[1] != 2 || value[3] != 0 || result < 0) {
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pr_warn("could not get sp_spi watchdog timeout (%li). Continuing\n",
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result);
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return fallback_value;
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}
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/* rtas uses minutes */
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return ((int)value[2]) * 60;
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}
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/**
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* wdrtas_timer_start - starts watchdog
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*
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* wdrtas_timer_start starts the watchdog by calling the RTAS function
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* set-interval (surveillance)
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*/
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static void wdrtas_timer_start(void)
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{
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wdrtas_set_interval(wdrtas_interval);
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}
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/**
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* wdrtas_timer_stop - stops watchdog
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*
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* wdrtas_timer_stop stops the watchdog timer by calling the RTAS function
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* set-interval (surveillance)
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*/
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static void wdrtas_timer_stop(void)
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{
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wdrtas_set_interval(0);
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}
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/**
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* wdrtas_timer_keepalive - resets watchdog timer to keep system alive
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*
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* wdrtas_timer_keepalive restarts the watchdog timer by calling the
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* RTAS function event-scan and repeats these calls as long as there are
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* events available. All events will be dumped.
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*/
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static void wdrtas_timer_keepalive(void)
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{
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long result;
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do {
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result = rtas_call(wdrtas_token_event_scan, 4, 1, NULL,
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RTAS_EVENT_SCAN_ALL_EVENTS, 0,
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(void *)__pa(wdrtas_logbuffer),
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WDRTAS_LOGBUFFER_LEN);
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if (result < 0)
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pr_err("event-scan failed: %li\n", result);
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if (result == 0)
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print_hex_dump(KERN_INFO, "dumping event, data: ",
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DUMP_PREFIX_OFFSET, 16, 1,
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wdrtas_logbuffer, WDRTAS_LOGBUFFER_LEN, false);
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} while (result == 0);
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}
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/**
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* wdrtas_get_temperature - returns current temperature
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*
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* returns temperature or <0 on failures
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*
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* wdrtas_get_temperature returns the current temperature in Fahrenheit. It
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* uses the RTAS call get-sensor-state, token 3 to do so
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*/
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static int wdrtas_get_temperature(void)
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{
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int result;
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int temperature = 0;
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result = rtas_get_sensor(WDRTAS_THERMAL_SENSOR, 0, &temperature);
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if (result < 0)
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pr_warn("reading the thermal sensor failed: %i\n", result);
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else
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temperature = ((temperature * 9) / 5) + 32; /* fahrenheit */
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return temperature;
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}
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/**
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* wdrtas_get_status - returns the status of the watchdog
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*
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* returns a bitmask of defines WDIOF_... as defined in
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* include/linux/watchdog.h
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*/
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static int wdrtas_get_status(void)
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{
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return 0; /* TODO */
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}
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/**
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* wdrtas_get_boot_status - returns the reason for the last boot
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*
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* returns a bitmask of defines WDIOF_... as defined in
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* include/linux/watchdog.h, indicating why the watchdog rebooted the system
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*/
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static int wdrtas_get_boot_status(void)
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{
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return 0; /* TODO */
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}
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/*** watchdog API and operations stuff */
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/* wdrtas_write - called when watchdog device is written to
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* @file: file structure
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* @buf: user buffer with data
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* @len: amount to data written
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* @ppos: position in file
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*
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* returns the number of successfully processed characters, which is always
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* the number of bytes passed to this function
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*
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* wdrtas_write processes all the data given to it and looks for the magic
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* character 'V'. This character allows the watchdog device to be closed
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* properly.
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*/
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static ssize_t wdrtas_write(struct file *file, const char __user *buf,
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size_t len, loff_t *ppos)
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{
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int i;
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char c;
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if (!len)
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goto out;
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if (!wdrtas_nowayout) {
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wdrtas_expect_close = 0;
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/* look for 'V' */
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for (i = 0; i < len; i++) {
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if (get_user(c, buf + i))
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return -EFAULT;
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/* allow to close device */
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if (c == 'V')
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wdrtas_expect_close = WDRTAS_MAGIC_CHAR;
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}
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}
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wdrtas_timer_keepalive();
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out:
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return len;
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}
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/**
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* wdrtas_ioctl - ioctl function for the watchdog device
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* @file: file structure
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* @cmd: command for ioctl
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* @arg: argument pointer
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*
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* returns 0 on success, <0 on failure
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*
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* wdrtas_ioctl implements the watchdog API ioctls
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*/
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static long wdrtas_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int __user *argp = (void __user *)arg;
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int i;
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static const struct watchdog_info wdinfo = {
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.options = WDRTAS_SUPPORTED_MASK,
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.firmware_version = 0,
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.identity = "wdrtas",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &wdinfo, sizeof(wdinfo)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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i = wdrtas_get_status();
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return put_user(i, argp);
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case WDIOC_GETBOOTSTATUS:
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i = wdrtas_get_boot_status();
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return put_user(i, argp);
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case WDIOC_GETTEMP:
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if (wdrtas_token_get_sensor_state == RTAS_UNKNOWN_SERVICE)
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return -EOPNOTSUPP;
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i = wdrtas_get_temperature();
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return put_user(i, argp);
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case WDIOC_SETOPTIONS:
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if (get_user(i, argp))
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return -EFAULT;
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if (i & WDIOS_DISABLECARD)
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wdrtas_timer_stop();
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if (i & WDIOS_ENABLECARD) {
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wdrtas_timer_keepalive();
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wdrtas_timer_start();
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}
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/* not implemented. Done by H8
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if (i & WDIOS_TEMPPANIC) {
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} */
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return 0;
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case WDIOC_KEEPALIVE:
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wdrtas_timer_keepalive();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(i, argp))
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return -EFAULT;
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if (wdrtas_set_interval(i))
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return -EINVAL;
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wdrtas_timer_keepalive();
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if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE)
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wdrtas_interval = i;
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else
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wdrtas_interval = wdrtas_get_interval(i);
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/* fallthrough */
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case WDIOC_GETTIMEOUT:
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return put_user(wdrtas_interval, argp);
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default:
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return -ENOTTY;
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}
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}
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/**
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* wdrtas_open - open function of watchdog device
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* @inode: inode structure
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* @file: file structure
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*
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* returns 0 on success, -EBUSY if the file has been opened already, <0 on
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* other failures
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*
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* function called when watchdog device is opened
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*/
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static int wdrtas_open(struct inode *inode, struct file *file)
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{
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/* only open once */
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if (atomic_inc_return(&wdrtas_miscdev_open) > 1) {
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atomic_dec(&wdrtas_miscdev_open);
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return -EBUSY;
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}
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wdrtas_timer_start();
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wdrtas_timer_keepalive();
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return stream_open(inode, file);
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}
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/**
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* wdrtas_close - close function of watchdog device
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* @inode: inode structure
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* @file: file structure
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*
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* returns 0 on success
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*
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* close function. Always succeeds
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*/
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static int wdrtas_close(struct inode *inode, struct file *file)
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{
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/* only stop watchdog, if this was announced using 'V' before */
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if (wdrtas_expect_close == WDRTAS_MAGIC_CHAR)
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wdrtas_timer_stop();
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else {
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pr_warn("got unexpected close. Watchdog not stopped.\n");
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wdrtas_timer_keepalive();
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}
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wdrtas_expect_close = 0;
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atomic_dec(&wdrtas_miscdev_open);
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return 0;
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}
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/**
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* wdrtas_temp_read - gives back the temperature in fahrenheit
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* @file: file structure
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* @buf: user buffer
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* @count: number of bytes to be read
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* @ppos: position in file
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*
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* returns always 1 or -EFAULT in case of user space copy failures, <0 on
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* other failures
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*
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* wdrtas_temp_read gives the temperature to the users by copying this
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* value as one byte into the user space buffer. The unit is Fahrenheit...
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*/
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static ssize_t wdrtas_temp_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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int temperature = 0;
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temperature = wdrtas_get_temperature();
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if (temperature < 0)
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return temperature;
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if (copy_to_user(buf, &temperature, 1))
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return -EFAULT;
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return 1;
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}
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/**
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* wdrtas_temp_open - open function of temperature device
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* @inode: inode structure
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* @file: file structure
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*
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* returns 0 on success, <0 on failure
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*
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* function called when temperature device is opened
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*/
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static int wdrtas_temp_open(struct inode *inode, struct file *file)
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{
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return stream_open(inode, file);
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}
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/**
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* wdrtas_temp_close - close function of temperature device
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* @inode: inode structure
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* @file: file structure
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*
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* returns 0 on success
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*
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* close function. Always succeeds
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*/
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static int wdrtas_temp_close(struct inode *inode, struct file *file)
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{
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return 0;
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}
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/**
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* wdrtas_reboot - reboot notifier function
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* @nb: notifier block structure
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* @code: reboot code
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* @ptr: unused
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*
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* returns NOTIFY_DONE
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*
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* wdrtas_reboot stops the watchdog in case of a reboot
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*/
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static int wdrtas_reboot(struct notifier_block *this,
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unsigned long code, void *ptr)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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wdrtas_timer_stop();
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return NOTIFY_DONE;
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}
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/*** initialization stuff */
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static const struct file_operations wdrtas_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = wdrtas_write,
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.unlocked_ioctl = wdrtas_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = wdrtas_open,
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.release = wdrtas_close,
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};
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static struct miscdevice wdrtas_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &wdrtas_fops,
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};
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static const struct file_operations wdrtas_temp_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.read = wdrtas_temp_read,
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.open = wdrtas_temp_open,
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.release = wdrtas_temp_close,
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};
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static struct miscdevice wdrtas_tempdev = {
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.minor = TEMP_MINOR,
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.name = "temperature",
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.fops = &wdrtas_temp_fops,
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};
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static struct notifier_block wdrtas_notifier = {
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.notifier_call = wdrtas_reboot,
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};
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/**
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* wdrtas_get_tokens - reads in RTAS tokens
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*
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* returns 0 on success, <0 on failure
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*
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* wdrtas_get_tokens reads in the tokens for the RTAS calls used in
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* this watchdog driver. It tolerates, if "get-sensor-state" and
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* "ibm,get-system-parameter" are not available.
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*/
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static int wdrtas_get_tokens(void)
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{
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wdrtas_token_get_sensor_state = rtas_token("get-sensor-state");
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if (wdrtas_token_get_sensor_state == RTAS_UNKNOWN_SERVICE) {
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pr_warn("couldn't get token for get-sensor-state. Trying to continue without temperature support.\n");
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}
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wdrtas_token_get_sp = rtas_token("ibm,get-system-parameter");
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if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE) {
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pr_warn("couldn't get token for ibm,get-system-parameter. Trying to continue with a default timeout value of %i seconds.\n",
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WDRTAS_DEFAULT_INTERVAL);
|
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}
|
|
|
|
wdrtas_token_set_indicator = rtas_token("set-indicator");
|
|
if (wdrtas_token_set_indicator == RTAS_UNKNOWN_SERVICE) {
|
|
pr_err("couldn't get token for set-indicator. Terminating watchdog code.\n");
|
|
return -EIO;
|
|
}
|
|
|
|
wdrtas_token_event_scan = rtas_token("event-scan");
|
|
if (wdrtas_token_event_scan == RTAS_UNKNOWN_SERVICE) {
|
|
pr_err("couldn't get token for event-scan. Terminating watchdog code.\n");
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* wdrtas_unregister_devs - unregisters the misc dev handlers
|
|
*
|
|
* wdrtas_register_devs unregisters the watchdog and temperature watchdog
|
|
* misc devs
|
|
*/
|
|
static void wdrtas_unregister_devs(void)
|
|
{
|
|
misc_deregister(&wdrtas_miscdev);
|
|
if (wdrtas_token_get_sensor_state != RTAS_UNKNOWN_SERVICE)
|
|
misc_deregister(&wdrtas_tempdev);
|
|
}
|
|
|
|
/**
|
|
* wdrtas_register_devs - registers the misc dev handlers
|
|
*
|
|
* returns 0 on success, <0 on failure
|
|
*
|
|
* wdrtas_register_devs registers the watchdog and temperature watchdog
|
|
* misc devs
|
|
*/
|
|
static int wdrtas_register_devs(void)
|
|
{
|
|
int result;
|
|
|
|
result = misc_register(&wdrtas_miscdev);
|
|
if (result) {
|
|
pr_err("couldn't register watchdog misc device. Terminating watchdog code.\n");
|
|
return result;
|
|
}
|
|
|
|
if (wdrtas_token_get_sensor_state != RTAS_UNKNOWN_SERVICE) {
|
|
result = misc_register(&wdrtas_tempdev);
|
|
if (result) {
|
|
pr_warn("couldn't register watchdog temperature misc device. Continuing without temperature support.\n");
|
|
wdrtas_token_get_sensor_state = RTAS_UNKNOWN_SERVICE;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* wdrtas_init - init function of the watchdog driver
|
|
*
|
|
* returns 0 on success, <0 on failure
|
|
*
|
|
* registers the file handlers and the reboot notifier
|
|
*/
|
|
static int __init wdrtas_init(void)
|
|
{
|
|
if (wdrtas_get_tokens())
|
|
return -ENODEV;
|
|
|
|
if (wdrtas_register_devs())
|
|
return -ENODEV;
|
|
|
|
if (register_reboot_notifier(&wdrtas_notifier)) {
|
|
pr_err("could not register reboot notifier. Terminating watchdog code.\n");
|
|
wdrtas_unregister_devs();
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (wdrtas_token_get_sp == RTAS_UNKNOWN_SERVICE)
|
|
wdrtas_interval = WDRTAS_DEFAULT_INTERVAL;
|
|
else
|
|
wdrtas_interval = wdrtas_get_interval(WDRTAS_DEFAULT_INTERVAL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* wdrtas_exit - exit function of the watchdog driver
|
|
*
|
|
* unregisters the file handlers and the reboot notifier
|
|
*/
|
|
static void __exit wdrtas_exit(void)
|
|
{
|
|
if (!wdrtas_nowayout)
|
|
wdrtas_timer_stop();
|
|
|
|
wdrtas_unregister_devs();
|
|
|
|
unregister_reboot_notifier(&wdrtas_notifier);
|
|
}
|
|
|
|
module_init(wdrtas_init);
|
|
module_exit(wdrtas_exit);
|