cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ip32-reset.c (3651B)

      1/*
      2 * This file is subject to the terms and conditions of the GNU General Public
      3 * License.  See the file "COPYING" in the main directory of this archive
      4 * for more details.
      5 *
      6 * Copyright (C) 2001 Keith M Wesolowski
      7 * Copyright (C) 2001 Paul Mundt
      8 * Copyright (C) 2003 Guido Guenther <agx@sigxcpu.org>
      9 */
     10
     11#include <linux/compiler.h>
     12#include <linux/init.h>
     13#include <linux/kernel.h>
     14#include <linux/module.h>
     15#include <linux/panic_notifier.h>
     16#include <linux/sched.h>
     17#include <linux/sched/signal.h>
     18#include <linux/notifier.h>
     19#include <linux/delay.h>
     20#include <linux/rtc/ds1685.h>
     21#include <linux/interrupt.h>
     22#include <linux/pm.h>
     23
     24#include <asm/addrspace.h>
     25#include <asm/irq.h>
     26#include <asm/reboot.h>
     27#include <asm/wbflush.h>
     28#include <asm/ip32/mace.h>
     29#include <asm/ip32/crime.h>
     30#include <asm/ip32/ip32_ints.h>
     31
     32#define POWERDOWN_TIMEOUT	120
     33/*
     34 * Blink frequency during reboot grace period and when panicked.
     35 */
     36#define POWERDOWN_FREQ		(HZ / 4)
     37#define PANIC_FREQ		(HZ / 8)
     38
     39extern struct platform_device ip32_rtc_device;
     40
     41static struct timer_list power_timer, blink_timer;
     42static unsigned long blink_timer_timeout;
     43static int has_panicked, shutting_down;
     44
     45static __noreturn void ip32_poweroff(void *data)
     46{
     47	void (*poweroff_func)(struct platform_device *) =
     48		symbol_get(ds1685_rtc_poweroff);
     49
     50#ifdef CONFIG_MODULES
     51	/* If the first __symbol_get failed, our module wasn't loaded. */
     52	if (!poweroff_func) {
     53		request_module("rtc-ds1685");
     54		poweroff_func = symbol_get(ds1685_rtc_poweroff);
     55	}
     56#endif
     57
     58	if (!poweroff_func)
     59		pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
     60	else {
     61		(*poweroff_func)((struct platform_device *)data);
     62		symbol_put(ds1685_rtc_poweroff);
     63	}
     64
     65	unreachable();
     66}
     67
     68static void ip32_machine_restart(char *cmd) __noreturn;
     69static void ip32_machine_restart(char *cmd)
     70{
     71	msleep(20);
     72	crime->control = CRIME_CONTROL_HARD_RESET;
     73	unreachable();
     74}
     75
     76static void blink_timeout(struct timer_list *unused)
     77{
     78	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
     79	mace->perif.ctrl.misc = led;
     80	mod_timer(&blink_timer, jiffies + blink_timer_timeout);
     81}
     82
     83static void ip32_machine_halt(void)
     84{
     85	ip32_poweroff(&ip32_rtc_device);
     86}
     87
     88static void power_timeout(struct timer_list *unused)
     89{
     90	ip32_poweroff(&ip32_rtc_device);
     91}
     92
     93void ip32_prepare_poweroff(void)
     94{
     95	if (has_panicked)
     96		return;
     97
     98	if (shutting_down || kill_cad_pid(SIGINT, 1)) {
     99		/* No init process or button pressed twice.  */
    100		ip32_poweroff(&ip32_rtc_device);
    101	}
    102
    103	shutting_down = 1;
    104	blink_timer_timeout = POWERDOWN_FREQ;
    105	blink_timeout(&blink_timer);
    106
    107	timer_setup(&power_timer, power_timeout, 0);
    108	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
    109	add_timer(&power_timer);
    110}
    111
    112static int panic_event(struct notifier_block *this, unsigned long event,
    113		       void *ptr)
    114{
    115	unsigned long led;
    116
    117	if (has_panicked)
    118		return NOTIFY_DONE;
    119	has_panicked = 1;
    120
    121	/* turn off the green LED */
    122	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
    123	mace->perif.ctrl.misc = led;
    124
    125	blink_timer_timeout = PANIC_FREQ;
    126	blink_timeout(&blink_timer);
    127
    128	return NOTIFY_DONE;
    129}
    130
    131static struct notifier_block panic_block = {
    132	.notifier_call = panic_event,
    133};
    134
    135static __init int ip32_reboot_setup(void)
    136{
    137	/* turn on the green led only */
    138	unsigned long led = mace->perif.ctrl.misc;
    139	led |= MACEISA_LED_RED;
    140	led &= ~MACEISA_LED_GREEN;
    141	mace->perif.ctrl.misc = led;
    142
    143	_machine_restart = ip32_machine_restart;
    144	_machine_halt = ip32_machine_halt;
    145	pm_power_off = ip32_machine_halt;
    146
    147	timer_setup(&blink_timer, blink_timeout, 0);
    148	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
    149
    150	return 0;
    151}
    152
    153subsys_initcall(ip32_reboot_setup);