linux/include/asm-ppc/time.h

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/*
* Common time prototypes and such for all ppc machines.
*
* Written by Cort Dougan (cort@fsmlabs.com) to merge
* Paul Mackerras' version and mine for PReP and Pmac.
*/
#ifdef __KERNEL__
#ifndef __ASM_TIME_H__
#define __ASM_TIME_H__
#include <linux/config.h>
#include <linux/types.h>
#include <linux/rtc.h>
#include <linux/threads.h>
#include <asm/reg.h>
/* time.c */
extern unsigned tb_ticks_per_jiffy;
extern unsigned tb_to_us;
extern unsigned tb_last_stamp;
extern unsigned long disarm_decr[NR_CPUS];
extern void to_tm(int tim, struct rtc_time * tm);
extern time_t last_rtc_update;
extern void set_dec_cpu6(unsigned int val);
int via_calibrate_decr(void);
/* Accessor functions for the decrementer register.
* The 4xx doesn't even have a decrementer. I tried to use the
* generic timer interrupt code, which seems OK, with the 4xx PIT
* in auto-reload mode. The problem is PIT stops counting when it
* hits zero. If it would wrap, we could use it just like a decrementer.
*/
static __inline__ unsigned int get_dec(void)
{
#if defined(CONFIG_40x)
return (mfspr(SPRN_PIT));
#else
return (mfspr(SPRN_DEC));
#endif
}
static __inline__ void set_dec(unsigned int val)
{
#if defined(CONFIG_40x)
return; /* Have to let it auto-reload */
#elif defined(CONFIG_8xx_CPU6)
set_dec_cpu6(val);
#else
mtspr(SPRN_DEC, val);
#endif
}
/* Accessor functions for the timebase (RTC on 601) registers. */
/* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
#ifdef CONFIG_6xx
extern __inline__ int const __USE_RTC(void) {
return (mfspr(SPRN_PVR)>>16) == 1;
}
#else
#define __USE_RTC() 0
#endif
extern __inline__ unsigned long get_tbl(void) {
unsigned long tbl;
#if defined(CONFIG_403GCX)
asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
#else
asm volatile("mftb %0" : "=r" (tbl));
#endif
return tbl;
}
extern __inline__ unsigned long get_tbu(void) {
unsigned long tbl;
#if defined(CONFIG_403GCX)
asm volatile("mfspr %0, 0x3dc" : "=r" (tbl));
#else
asm volatile("mftbu %0" : "=r" (tbl));
#endif
return tbl;
}
extern __inline__ void set_tb(unsigned int upper, unsigned int lower)
{
mtspr(SPRN_TBWL, 0);
mtspr(SPRN_TBWU, upper);
mtspr(SPRN_TBWL, lower);
}
extern __inline__ unsigned long get_rtcl(void) {
unsigned long rtcl;
asm volatile("mfrtcl %0" : "=r" (rtcl));
return rtcl;
}
extern __inline__ unsigned long get_rtcu(void)
{
unsigned long rtcu;
asm volatile("mfrtcu %0" : "=r" (rtcu));
return rtcu;
}
extern __inline__ unsigned get_native_tbl(void) {
if (__USE_RTC())
return get_rtcl();
else
return get_tbl();
}
/* On machines with RTC, this function can only be used safely
* after the timestamp and for 1 second. It is only used by gettimeofday
* however so it should not matter.
*/
extern __inline__ unsigned tb_ticks_since(unsigned tstamp) {
if (__USE_RTC()) {
int delta = get_rtcl() - tstamp;
return delta<0 ? delta + 1000000000 : delta;
} else {
return get_tbl() - tstamp;
}
}
#if 0
extern __inline__ unsigned long get_bin_rtcl(void) {
unsigned long rtcl, rtcu1, rtcu2;
asm volatile("\
1: mfrtcu %0\n\
mfrtcl %1\n\
mfrtcu %2\n\
cmpw %0,%2\n\
bne- 1b\n"
: "=r" (rtcu1), "=r" (rtcl), "=r" (rtcu2)
: : "cr0");
return rtcu2*1000000000+rtcl;
}
extern __inline__ unsigned binary_tbl(void) {
if (__USE_RTC())
return get_bin_rtcl();
else
return get_tbl();
}
#endif
/* Use mulhwu to scale processor timebase to timeval */
/* Specifically, this computes (x * y) / 2^32. -- paulus */
#define mulhwu(x,y) \
({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
unsigned mulhwu_scale_factor(unsigned, unsigned);
#endif /* __ASM_TIME_H__ */
#endif /* __KERNEL__ */