linux/arch/mips/kernel/time.c
Baolin Wang f06e7aa47f
MIPS: Convert update_persistent_clock() to update_persistent_clock64()
Since struct timespec is not y2038 safe on 32bit machines, this patch
converts update_persistent_clock() to update_persistent_clock64() using
struct timespec64.

The rtc_mips_set_time() and rtc_mips_set_mmss() interfaces were using
'unsigned long' type that is not y2038 safe on 32bit machines, moreover
there is only one platform implementing rtc_mips_set_time() and two
platforms implementing rtc_mips_set_mmss(), so we can just make them each
implement update_persistent_clock64() directly, to get that helper out
of the common mips code by removing rtc_mips_set_time() and
rtc_mips_set_mmss() interfaces.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: James Hogan <jhogan@kernel.org>
2018-05-14 23:58:23 +01:00

107 lines
2.6 KiB
C

/*
* Copyright 2001 MontaVista Software Inc.
* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
* Copyright (c) 2003, 2004 Maciej W. Rozycki
*
* Common time service routines for MIPS machines.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/bug.h>
#include <linux/clockchips.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <asm/cpu-features.h>
#include <asm/cpu-type.h>
#include <asm/div64.h>
#include <asm/time.h>
/*
* forward reference
*/
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
static int null_perf_irq(void)
{
return 0;
}
int (*perf_irq)(void) = null_perf_irq;
EXPORT_SYMBOL(perf_irq);
/*
* time_init() - it does the following things.
*
* 1) plat_time_init() -
* a) (optional) set up RTC routines,
* b) (optional) calibrate and set the mips_hpt_frequency
* (only needed if you intended to use cpu counter as timer interrupt
* source)
* 2) calculate a couple of cached variables for later usage
*/
unsigned int mips_hpt_frequency;
EXPORT_SYMBOL_GPL(mips_hpt_frequency);
static __init int cpu_has_mfc0_count_bug(void)
{
switch (current_cpu_type()) {
case CPU_R4000PC:
case CPU_R4000SC:
case CPU_R4000MC:
/*
* V3.0 is documented as suffering from the mfc0 from count bug.
* Afaik this is the last version of the R4000. Later versions
* were marketed as R4400.
*/
return 1;
case CPU_R4400PC:
case CPU_R4400SC:
case CPU_R4400MC:
/*
* The published errata for the R4400 up to 3.0 say the CPU
* has the mfc0 from count bug.
*/
if ((current_cpu_data.processor_id & 0xff) <= 0x30)
return 1;
/*
* we assume newer revisions are ok
*/
return 0;
}
return 0;
}
void __init time_init(void)
{
plat_time_init();
/*
* The use of the R4k timer as a clock event takes precedence;
* if reading the Count register might interfere with the timer
* interrupt, then we don't use the timer as a clock source.
* We may still use the timer as a clock source though if the
* timer interrupt isn't reliable; the interference doesn't
* matter then, because we don't use the interrupt.
*/
if (mips_clockevent_init() != 0 || !cpu_has_mfc0_count_bug())
init_mips_clocksource();
}