LXR linux/arch/powerpc/include/asm/time.h

   1/*
   2 * Common time prototypes and such for all ppc machines.
   3 *
   4 * Written by Cort Dougan (cort@cs.nmt.edu) to merge
   5 * Paul Mackerras' version and mine for PReP and Pmac.
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the License, or (at your option) any later version.
  11 */
  12
  13#ifndef __POWERPC_TIME_H
  14#define __POWERPC_TIME_H
  15
  16#ifdef __KERNEL__
  17#include <linux/types.h>
  18#include <linux/percpu.h>
  19
  20#include <asm/processor.h>
  21#include <asm/cpu_has_feature.h>
  22
  23/* time.c */
  24extern unsigned long tb_ticks_per_jiffy;
  25extern unsigned long tb_ticks_per_usec;
  26extern unsigned long tb_ticks_per_sec;
  27extern struct clock_event_device decrementer_clockevent;
  28
  29
  30extern void generic_calibrate_decr(void);
  31extern void hdec_interrupt(struct pt_regs *regs);
  32
  33/* Some sane defaults: 125 MHz timebase, 1GHz processor */
  34extern unsigned long ppc_proc_freq;
  35#define DEFAULT_PROC_FREQ       (DEFAULT_TB_FREQ * 8)
  36extern unsigned long ppc_tb_freq;
  37#define DEFAULT_TB_FREQ         125000000UL
  38
  39struct div_result {
  40        u64 result_high;
  41        u64 result_low;
  42};
  43
  44/* Accessor functions for the timebase (RTC on 601) registers. */
  45/* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
  46#ifdef CONFIG_6xx
  47#define __USE_RTC()     (cpu_has_feature(CPU_FTR_USE_RTC))
  48#else
  49#define __USE_RTC()     0
  50#endif
  51
  52#ifdef CONFIG_PPC64
  53
  54/* For compatibility, get_tbl() is defined as get_tb() on ppc64 */
  55#define get_tbl         get_tb
  56
  57#else
  58
  59static inline unsigned long get_tbl(void)
  60{
  61#if defined(CONFIG_403GCX)
  62        unsigned long tbl;
  63        asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
  64        return tbl;
  65#else
  66        return mftbl();
  67#endif
  68}
  69
  70static inline unsigned int get_tbu(void)
  71{
  72#ifdef CONFIG_403GCX
  73        unsigned int tbu;
  74        asm volatile("mfspr %0, 0x3dc" : "=r" (tbu));
  75        return tbu;
  76#else
  77        return mftbu();
  78#endif
  79}
  80#endif /* !CONFIG_PPC64 */
  81
  82static inline unsigned int get_rtcl(void)
  83{
  84        unsigned int rtcl;
  85
  86        asm volatile("mfrtcl %0" : "=r" (rtcl));
  87        return rtcl;
  88}
  89
  90static inline u64 get_rtc(void)
  91{
  92        unsigned int hi, lo, hi2;
  93
  94        do {
  95                asm volatile("mfrtcu %0; mfrtcl %1; mfrtcu %2"
  96                             : "=r" (hi), "=r" (lo), "=r" (hi2));
  97        } while (hi2 != hi);
  98        return (u64)hi * 1000000000 + lo;
  99}
 100
 101static inline u64 get_vtb(void)
 102{
 103#ifdef CONFIG_PPC_BOOK3S_64
 104        if (cpu_has_feature(CPU_FTR_ARCH_207S))
 105                return mfspr(SPRN_VTB);
 106#endif
 107        return 0;
 108}
 109
 110#ifdef CONFIG_PPC64
 111static inline u64 get_tb(void)
 112{
 113        return mftb();
 114}
 115#else /* CONFIG_PPC64 */
 116static inline u64 get_tb(void)
 117{
 118        unsigned int tbhi, tblo, tbhi2;
 119
 120        do {
 121                tbhi = get_tbu();
 122                tblo = get_tbl();
 123                tbhi2 = get_tbu();
 124        } while (tbhi != tbhi2);
 125
 126        return ((u64)tbhi << 32) | tblo;
 127}
 128#endif /* !CONFIG_PPC64 */
 129
 130static inline u64 get_tb_or_rtc(void)
 131{
 132        return __USE_RTC() ? get_rtc() : get_tb();
 133}
 134
 135static inline void set_tb(unsigned int upper, unsigned int lower)
 136{
 137        mtspr(SPRN_TBWL, 0);
 138        mtspr(SPRN_TBWU, upper);
 139        mtspr(SPRN_TBWL, lower);
 140}
 141
 142/* Accessor functions for the decrementer register.
 143 * The 4xx doesn't even have a decrementer.  I tried to use the
 144 * generic timer interrupt code, which seems OK, with the 4xx PIT
 145 * in auto-reload mode.  The problem is PIT stops counting when it
 146 * hits zero.  If it would wrap, we could use it just like a decrementer.
 147 */
 148static inline u64 get_dec(void)
 149{
 150#if defined(CONFIG_40x)
 151        return (mfspr(SPRN_PIT));
 152#else
 153        return (mfspr(SPRN_DEC));
 154#endif
 155}
 156
 157/*
 158 * Note: Book E and 4xx processors differ from other PowerPC processors
 159 * in when the decrementer generates its interrupt: on the 1 to 0
 160 * transition for Book E/4xx, but on the 0 to -1 transition for others.
 161 */
 162static inline void set_dec(u64 val)
 163{
 164#if defined(CONFIG_40x)
 165        mtspr(SPRN_PIT, (u32) val);
 166#else
 167#ifndef CONFIG_BOOKE
 168        --val;
 169#endif
 170        mtspr(SPRN_DEC, val);
 171#endif /* not 40x */
 172}
 173
 174static inline unsigned long tb_ticks_since(unsigned long tstamp)
 175{
 176        if (__USE_RTC()) {
 177                int delta = get_rtcl() - (unsigned int) tstamp;
 178                return delta < 0 ? delta + 1000000000 : delta;
 179        }
 180        return get_tbl() - tstamp;
 181}
 182
 183#define mulhwu(x,y) \
 184({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
 185
 186#ifdef CONFIG_PPC64
 187#define mulhdu(x,y) \
 188({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
 189#else
 190extern u64 mulhdu(u64, u64);
 191#endif
 192
 193extern void div128_by_32(u64 dividend_high, u64 dividend_low,
 194                         unsigned divisor, struct div_result *dr);
 195
 196extern void secondary_cpu_time_init(void);
 197extern void __init time_init(void);
 198
 199DECLARE_PER_CPU(u64, decrementers_next_tb);
 200
 201/* Convert timebase ticks to nanoseconds */
 202unsigned long long tb_to_ns(unsigned long long tb_ticks);
 203
 204#endif /* __KERNEL__ */
 205#endif /* __POWERPC_TIME_H */
 206