u-boot/arch/x86/lib/tsc_timer.c

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/*
* Copyright (c) 2012 The Chromium OS Authors.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/i8254.h>
#include <asm/ibmpc.h>
#include <asm/msr.h>
#include <asm/u-boot-x86.h>
DECLARE_GLOBAL_DATA_PTR;
void timer_set_base(u64 base)
{
gd->arch.tsc_base = base;
}
/*
* Get the number of CPU time counter ticks since it was read first time after
* restart. This yields a free running counter guaranteed to take almost 6
* years to wrap around even at 100GHz clock rate.
*/
u64 __attribute__((no_instrument_function)) get_ticks(void)
{
u64 now_tick = rdtsc();
/* We assume that 0 means the base hasn't been set yet */
if (!gd->arch.tsc_base)
panic("No tick base available");
return now_tick - gd->arch.tsc_base;
}
#define PLATFORM_INFO_MSR 0xce
/* Get the speed of the TSC timer in MHz */
unsigned __attribute__((no_instrument_function)) long get_tbclk_mhz(void)
{
u32 ratio;
u64 platform_info = native_read_msr(PLATFORM_INFO_MSR);
/* 100MHz times Max Non Turbo ratio */
ratio = (platform_info >> 8) & 0xff;
return 100 * ratio;
}
unsigned long get_tbclk(void)
{
return get_tbclk_mhz() * 1000 * 1000;
}
static ulong get_ms_timer(void)
{
return (get_ticks() * 1000) / get_tbclk();
}
ulong get_timer(ulong base)
{
return get_ms_timer() - base;
}
ulong __attribute__((no_instrument_function)) timer_get_us(void)
{
return get_ticks() / get_tbclk_mhz();
}
ulong timer_get_boot_us(void)
{
return timer_get_us();
}
void __udelay(unsigned long usec)
{
u64 now = get_ticks();
u64 stop;
stop = now + usec * get_tbclk_mhz();
while ((int64_t)(stop - get_ticks()) > 0)
;
}
int timer_init(void)
{
#ifdef CONFIG_SYS_PCAT_TIMER
/* Set up the PCAT timer if required */
pcat_timer_init();
#endif
return 0;
}