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 (791B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  Cobalt time initialization.
      4 *
      5 *  Copyright (C) 2007  Yoichi Yuasa <yuasa@linux-mips.org>
      6 */
      7#include <linux/i8253.h>
      8#include <linux/init.h>
      9
     10#include <asm/gt64120.h>
     11#include <asm/time.h>
     12
     13#define GT641XX_BASE_CLOCK	50000000	/* 50MHz */
     14
     15void __init plat_time_init(void)
     16{
     17	u32 start, end;
     18	int i = HZ / 10;
     19
     20	setup_pit_timer();
     21
     22	gt641xx_set_base_clock(GT641XX_BASE_CLOCK);
     23
     24	/*
     25	 * MIPS counter frequency is measured during a 100msec interval
     26	 * using GT64111 timer0.
     27	 */
     28	while (!gt641xx_timer0_state())
     29		;
     30
     31	start = read_c0_count();
     32
     33	while (i--)
     34		while (!gt641xx_timer0_state())
     35			;
     36
     37	end = read_c0_count();
     38
     39	mips_hpt_frequency = (end - start) * 10;
     40	printk(KERN_INFO "MIPS counter frequency %dHz\n", mips_hpt_frequency);
     41}