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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timers.c (3355B)

      1/***************************************************************************/
      2
      3/*
      4 *  timers.c - Generic hardware timer support.
      5 *
      6 *  Copyright (C) 1993 Hamish Macdonald
      7 *  Copyright (C) 1999 D. Jeff Dionne
      8 *  Copyright (C) 2001 Georges Menie, Ken Desmet
      9 *
     10 * This file is subject to the terms and conditions of the GNU General Public
     11 * License.  See the file COPYING in the main directory of this archive
     12 * for more details.
     13 */
     14
     15/***************************************************************************/
     16
     17#include <linux/types.h>
     18#include <linux/kernel.h>
     19#include <linux/mm.h>
     20#include <linux/interrupt.h>
     21#include <linux/irq.h>
     22#include <linux/clocksource.h>
     23#include <linux/rtc.h>
     24#include <asm/setup.h>
     25#include <asm/machdep.h>
     26#include <asm/MC68VZ328.h>
     27
     28/***************************************************************************/
     29
     30#if defined(CONFIG_DRAGEN2)
     31/* with a 33.16 MHz clock, this will give usec resolution to the time functions */
     32#define CLOCK_SOURCE	TCTL_CLKSOURCE_SYSCLK
     33#define CLOCK_PRE	7
     34#define TICKS_PER_JIFFY	41450
     35
     36#elif defined(CONFIG_XCOPILOT_BUGS)
     37/*
     38 * The only thing I know is that CLK32 is not available on Xcopilot
     39 * I have little idea about what frequency SYSCLK has on Xcopilot.
     40 * The values for prescaler and compare registers were simply
     41 * taken from the original source
     42 */
     43#define CLOCK_SOURCE	TCTL_CLKSOURCE_SYSCLK
     44#define CLOCK_PRE	2
     45#define TICKS_PER_JIFFY	0xd7e4
     46
     47#else
     48/* default to using the 32Khz clock */
     49#define CLOCK_SOURCE	TCTL_CLKSOURCE_32KHZ
     50#define CLOCK_PRE	31
     51#define TICKS_PER_JIFFY	10
     52#endif
     53
     54static u32 m68328_tick_cnt;
     55
     56/***************************************************************************/
     57
     58static irqreturn_t hw_tick(int irq, void *dummy)
     59{
     60	/* Reset Timer1 */
     61	TSTAT &= 0;
     62
     63	m68328_tick_cnt += TICKS_PER_JIFFY;
     64	legacy_timer_tick(1);
     65	return IRQ_HANDLED;
     66}
     67
     68/***************************************************************************/
     69
     70static u64 m68328_read_clk(struct clocksource *cs)
     71{
     72	unsigned long flags;
     73	u32 cycles;
     74
     75	local_irq_save(flags);
     76	cycles = m68328_tick_cnt + TCN;
     77	local_irq_restore(flags);
     78
     79	return cycles;
     80}
     81
     82/***************************************************************************/
     83
     84static struct clocksource m68328_clk = {
     85	.name	= "timer",
     86	.rating	= 250,
     87	.read	= m68328_read_clk,
     88	.mask	= CLOCKSOURCE_MASK(32),
     89	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
     90};
     91
     92/***************************************************************************/
     93
     94void hw_timer_init(void)
     95{
     96	int ret;
     97
     98	/* disable timer 1 */
     99	TCTL = 0;
    100
    101	/* set ISR */
    102	ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL);
    103	if (ret) {
    104		pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM,
    105		       ERR_PTR(ret));
    106	}
    107
    108	/* Restart mode, Enable int, Set clock source */
    109	TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
    110	TPRER = CLOCK_PRE;
    111	TCMP = TICKS_PER_JIFFY;
    112
    113	/* Enable timer 1 */
    114	TCTL |= TCTL_TEN;
    115	clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
    116}
    117
    118/***************************************************************************/
    119
    120int m68328_hwclk(int set, struct rtc_time *t)
    121{
    122	if (!set) {
    123		long now = RTCTIME;
    124		t->tm_year = 1;
    125		t->tm_mon = 0;
    126		t->tm_mday = 1;
    127		t->tm_hour = (now >> 24) % 24;
    128		t->tm_min = (now >> 16) % 60;
    129		t->tm_sec = now % 60;
    130	}
    131
    132	return 0;
    133}
    134
    135/***************************************************************************/