提交 72fc19ff 编写于 作者: R Ralf Baechle

[MIPS] Fix and cleanup the MIPS part of the (ab)use of CLOCK_TICK_RATE.

This is the clock rate of the i8253 PIT.  A MIPS system may not have
a PIT by the symbol is used all over the kernel including some APIs.
So keeping it defined to the number for the PIT is the only sane thing
for now.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
上级 c9294022
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003 by Ralf Baechle
*/
#ifndef __ASM_MACH_AU1X00_TIMEX_H
#define __ASM_MACH_AU1X00_TIMEX_H
#define CLOCK_TICK_RATE ((HZ * 100000UL) / 2)
#endif /* __ASM_MACH_AU1X00_TIMEX_H */
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003, 2005 by Ralf Baechle
*/
#ifndef __ASM_MACH_GENERIC_TIMEX_H
#define __ASM_MACH_GENERIC_TIMEX_H
#define CLOCK_TICK_RATE 500000
#endif /* __ASM_MACH_GENERIC_TIMEX_H */
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003 by Ralf Baechle
*/
#ifndef __ASM_MACH_JAZZ_TIMEX_H
#define __ASM_MACH_JAZZ_TIMEX_H
/*
* Jazz is still using the R4030 100Hz counter
*/
#define CLOCK_TICK_RATE 100
#endif /* __ASM_MACH_JAZZ_TIMEX_H */
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2005 Daniel Jacobowitz
*/
#ifndef __ASM_MACH_QEMU_TIMEX_H
#define __ASM_MACH_QEMU_TIMEX_H
/*
* We use a simulated i8254 PIC...
*/
#define CLOCK_TICK_RATE 1193182
#endif /* __ASM_MACH_QEMU_TIMEX_H */
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003, 2005 by Ralf Baechle
*/
#ifndef __ASM_MACH_RM200_TIMEX_H
#define __ASM_MACH_RM200_TIMEX_H
#define CLOCK_TICK_RATE 1193182
#endif /* __ASM_MACH_RM200_TIMEX_H */
......@@ -13,27 +13,12 @@
#include <asm/mipsregs.h>
/*
* This is the frequency of the timer used for Linux's timer interrupt.
* The value should be defined as accurate as possible or under certain
* circumstances Linux timekeeping might become inaccurate or fail.
*
* For many system the exact clockrate of the timer isn't known but due to
* the way this value is used we can get away with a wrong value as long
* as this value is:
*
* - a multiple of HZ
* - a divisor of the actual rate
*
* 500000 is a good such cheat value.
*
* The obscure number 1193182 is the same as used by the original i8254
* time in legacy PC hardware; the chip unfortunately also found in a
* bunch of MIPS systems. The last remaining user of the i8254 for the
* timer interrupt is the RM200; it's a very standard system so there is
* no reason to make this a separate architecture.
* This is the clock rate of the i8253 PIT. A MIPS system may not have
* a PIT by the symbol is used all over the kernel including some APIs.
* So keeping it defined to the number for the PIT is the only sane thing
* for now.
*/
#include <timex.h>
#define CLOCK_TICK_RATE 1193182
/*
* Standard way to access the cycle counter.
......
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