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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time.c (3797B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  linux/arch/m68k/kernel/time.c
      4 *
      5 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
      6 *
      7 * This file contains the m68k-specific time handling details.
      8 * Most of the stuff is located in the machine specific files.
      9 *
     10 * 1997-09-10	Updated NTP code according to technical memorandum Jan '96
     11 *		"A Kernel Model for Precision Timekeeping" by Dave Mills
     12 */
     13
     14#include <linux/errno.h>
     15#include <linux/export.h>
     16#include <linux/module.h>
     17#include <linux/sched.h>
     18#include <linux/sched/loadavg.h>
     19#include <linux/kernel.h>
     20#include <linux/param.h>
     21#include <linux/string.h>
     22#include <linux/mm.h>
     23#include <linux/rtc.h>
     24#include <linux/platform_device.h>
     25
     26#include <asm/machdep.h>
     27#include <asm/io.h>
     28#include <asm/irq_regs.h>
     29
     30#include <linux/time.h>
     31#include <linux/timex.h>
     32#include <linux/profile.h>
     33
     34
     35unsigned long (*mach_random_get_entropy)(void);
     36EXPORT_SYMBOL_GPL(mach_random_get_entropy);
     37
     38#ifdef CONFIG_HEARTBEAT
     39void timer_heartbeat(void)
     40{
     41	/* use power LED as a heartbeat instead -- much more useful
     42	   for debugging -- based on the version for PReP by Cort */
     43	/* acts like an actual heart beat -- ie thump-thump-pause... */
     44	if (mach_heartbeat) {
     45	    static unsigned cnt = 0, period = 0, dist = 0;
     46
     47	    if (cnt == 0 || cnt == dist)
     48		mach_heartbeat( 1 );
     49	    else if (cnt == 7 || cnt == dist+7)
     50		mach_heartbeat( 0 );
     51
     52	    if (++cnt > period) {
     53		cnt = 0;
     54		/* The hyperbolic function below modifies the heartbeat period
     55		 * length in dependency of the current (5min) load. It goes
     56		 * through the points f(0)=126, f(1)=86, f(5)=51,
     57		 * f(inf)->30. */
     58		period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
     59		dist = period / 4;
     60	    }
     61	}
     62}
     63#endif /* CONFIG_HEARTBEAT */
     64
     65#ifdef CONFIG_M68KCLASSIC
     66/* machine dependent timer functions */
     67int (*mach_hwclk) (int, struct rtc_time*);
     68EXPORT_SYMBOL(mach_hwclk);
     69
     70int (*mach_get_rtc_pll)(struct rtc_pll_info *);
     71int (*mach_set_rtc_pll)(struct rtc_pll_info *);
     72EXPORT_SYMBOL(mach_get_rtc_pll);
     73EXPORT_SYMBOL(mach_set_rtc_pll);
     74
     75#if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC)
     76void read_persistent_clock64(struct timespec64 *ts)
     77{
     78	struct rtc_time time;
     79
     80	ts->tv_sec = 0;
     81	ts->tv_nsec = 0;
     82
     83	if (!mach_hwclk)
     84		return;
     85
     86	mach_hwclk(0, &time);
     87
     88	ts->tv_sec = mktime64(time.tm_year + 1900, time.tm_mon + 1, time.tm_mday,
     89			      time.tm_hour, time.tm_min, time.tm_sec);
     90}
     91#endif
     92
     93#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
     94static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
     95{
     96	mach_hwclk(0, tm);
     97	return 0;
     98}
     99
    100static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
    101{
    102	if (mach_hwclk(1, tm) < 0)
    103		return -EOPNOTSUPP;
    104	return 0;
    105}
    106
    107static int rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
    108{
    109	struct rtc_pll_info pll;
    110	struct rtc_pll_info __user *argp = (void __user *)arg;
    111
    112	switch (cmd) {
    113	case RTC_PLL_GET:
    114		if (!mach_get_rtc_pll || mach_get_rtc_pll(&pll))
    115			return -EINVAL;
    116		return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
    117
    118	case RTC_PLL_SET:
    119		if (!mach_set_rtc_pll)
    120			return -EINVAL;
    121		if (!capable(CAP_SYS_TIME))
    122			return -EACCES;
    123		if (copy_from_user(&pll, argp, sizeof(pll)))
    124			return -EFAULT;
    125		return mach_set_rtc_pll(&pll);
    126	}
    127
    128	return -ENOIOCTLCMD;
    129}
    130
    131static const struct rtc_class_ops generic_rtc_ops = {
    132	.ioctl = rtc_ioctl,
    133	.read_time = rtc_generic_get_time,
    134	.set_time = rtc_generic_set_time,
    135};
    136
    137static int __init rtc_init(void)
    138{
    139	struct platform_device *pdev;
    140
    141	if (!mach_hwclk)
    142		return -ENODEV;
    143
    144	pdev = platform_device_register_data(NULL, "rtc-generic", -1,
    145					     &generic_rtc_ops,
    146					     sizeof(generic_rtc_ops));
    147	return PTR_ERR_OR_ZERO(pdev);
    148}
    149
    150module_init(rtc_init);
    151#endif /* CONFIG_RTC_DRV_GENERIC */
    152#endif /* CONFIG M68KCLASSIC */
    153
    154void __init time_init(void)
    155{
    156	mach_sched_init();
    157}