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 (4115B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
      4 *
      5 * Adapted for PowerPC (PReP) by Gary Thomas
      6 * Modified by Cort Dougan (cort@cs.nmt.edu).
      7 * Copied and modified from arch/i386/kernel/time.c
      8 *
      9 */
     10#include <linux/errno.h>
     11#include <linux/sched.h>
     12#include <linux/kernel.h>
     13#include <linux/param.h>
     14#include <linux/string.h>
     15#include <linux/mm.h>
     16#include <linux/interrupt.h>
     17#include <linux/time.h>
     18#include <linux/timex.h>
     19#include <linux/kernel_stat.h>
     20#include <linux/mc146818rtc.h>
     21#include <linux/init.h>
     22#include <linux/bcd.h>
     23#include <linux/ioport.h>
     24#include <linux/of_address.h>
     25
     26#include <asm/io.h>
     27#include <asm/nvram.h>
     28#include <asm/sections.h>
     29#include <asm/time.h>
     30
     31#include <platforms/chrp/chrp.h>
     32
     33#define NVRAM_AS0  0x74
     34#define NVRAM_AS1  0x75
     35#define NVRAM_DATA 0x77
     36
     37static int nvram_as1 = NVRAM_AS1;
     38static int nvram_as0 = NVRAM_AS0;
     39static int nvram_data = NVRAM_DATA;
     40
     41long __init chrp_time_init(void)
     42{
     43	struct device_node *rtcs;
     44	struct resource r;
     45	int base;
     46
     47	rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
     48	if (rtcs == NULL)
     49		rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc");
     50	if (rtcs == NULL)
     51		return 0;
     52	if (of_address_to_resource(rtcs, 0, &r)) {
     53		of_node_put(rtcs);
     54		return 0;
     55	}
     56	of_node_put(rtcs);
     57
     58	base = r.start;
     59	nvram_as1 = 0;
     60	nvram_as0 = base;
     61	nvram_data = base + 1;
     62
     63	return 0;
     64}
     65
     66static int chrp_cmos_clock_read(int addr)
     67{
     68	if (nvram_as1 != 0)
     69		outb(addr>>8, nvram_as1);
     70	outb(addr, nvram_as0);
     71	return (inb(nvram_data));
     72}
     73
     74static void chrp_cmos_clock_write(unsigned long val, int addr)
     75{
     76	if (nvram_as1 != 0)
     77		outb(addr>>8, nvram_as1);
     78	outb(addr, nvram_as0);
     79	outb(val, nvram_data);
     80	return;
     81}
     82
     83/*
     84 * Set the hardware clock. -- Cort
     85 */
     86int chrp_set_rtc_time(struct rtc_time *tmarg)
     87{
     88	unsigned char save_control, save_freq_select;
     89	struct rtc_time tm = *tmarg;
     90
     91	spin_lock(&rtc_lock);
     92
     93	save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */
     94
     95	chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL);
     96
     97	save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
     98
     99	chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
    100
    101	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
    102		tm.tm_sec = bin2bcd(tm.tm_sec);
    103		tm.tm_min = bin2bcd(tm.tm_min);
    104		tm.tm_hour = bin2bcd(tm.tm_hour);
    105		tm.tm_mon = bin2bcd(tm.tm_mon);
    106		tm.tm_mday = bin2bcd(tm.tm_mday);
    107		tm.tm_year = bin2bcd(tm.tm_year);
    108	}
    109	chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS);
    110	chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES);
    111	chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS);
    112	chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH);
    113	chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH);
    114	chrp_cmos_clock_write(tm.tm_year,RTC_YEAR);
    115
    116	/* The following flags have to be released exactly in this order,
    117	 * otherwise the DS12887 (popular MC146818A clone with integrated
    118	 * battery and quartz) will not reset the oscillator and will not
    119	 * update precisely 500 ms later. You won't find this mentioned in
    120	 * the Dallas Semiconductor data sheets, but who believes data
    121	 * sheets anyway ...                           -- Markus Kuhn
    122	 */
    123	chrp_cmos_clock_write(save_control, RTC_CONTROL);
    124	chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT);
    125
    126	spin_unlock(&rtc_lock);
    127	return 0;
    128}
    129
    130void chrp_get_rtc_time(struct rtc_time *tm)
    131{
    132	unsigned int year, mon, day, hour, min, sec;
    133
    134	do {
    135		sec = chrp_cmos_clock_read(RTC_SECONDS);
    136		min = chrp_cmos_clock_read(RTC_MINUTES);
    137		hour = chrp_cmos_clock_read(RTC_HOURS);
    138		day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH);
    139		mon = chrp_cmos_clock_read(RTC_MONTH);
    140		year = chrp_cmos_clock_read(RTC_YEAR);
    141	} while (sec != chrp_cmos_clock_read(RTC_SECONDS));
    142
    143	if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
    144		sec = bcd2bin(sec);
    145		min = bcd2bin(min);
    146		hour = bcd2bin(hour);
    147		day = bcd2bin(day);
    148		mon = bcd2bin(mon);
    149		year = bcd2bin(year);
    150	}
    151	if (year < 70)
    152		year += 100;
    153	tm->tm_sec = sec;
    154	tm->tm_min = min;
    155	tm->tm_hour = hour;
    156	tm->tm_mday = day;
    157	tm->tm_mon = mon;
    158	tm->tm_year = year;
    159}