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

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * Common time prototypes and such for all ppc machines.
   4 *
   5 * Written by Cort Dougan (cort@cs.nmt.edu) to merge
   6 * Paul Mackerras' version and mine for PReP and Pmac.
   7 */
   8
   9#ifndef __POWERPC_TIME_H
  10#define __POWERPC_TIME_H
  11
  12#ifdef __KERNEL__
  13#include <linux/types.h>
  14#include <linux/percpu.h>
  15
  16#include <asm/processor.h>
  17#include <asm/cpu_has_feature.h>
  18#include <asm/vdso/timebase.h>
  19
  20/* time.c */
  21extern u64 decrementer_max;
  22
  23extern unsigned long tb_ticks_per_jiffy;
  24extern unsigned long tb_ticks_per_usec;
  25extern unsigned long tb_ticks_per_sec;
  26extern struct clock_event_device decrementer_clockevent;
  27
  28
  29extern void generic_calibrate_decr(void);
  30
  31/* Some sane defaults: 125 MHz timebase, 1GHz processor */
  32extern unsigned long ppc_proc_freq;
  33#define DEFAULT_PROC_FREQ       (DEFAULT_TB_FREQ * 8)
  34extern unsigned long ppc_tb_freq;
  35#define DEFAULT_TB_FREQ         125000000UL
  36
  37extern bool tb_invalid;
  38
  39struct div_result {
  40        u64 result_high;
  41        u64 result_low;
  42};
  43
  44static inline u64 get_vtb(void)
  45{
  46        if (cpu_has_feature(CPU_FTR_ARCH_207S))
  47                return mfspr(SPRN_VTB);
  48
  49        return 0;
  50}
  51
  52/* Accessor functions for the decrementer register.
  53 * The 4xx doesn't even have a decrementer.  I tried to use the
  54 * generic timer interrupt code, which seems OK, with the 4xx PIT
  55 * in auto-reload mode.  The problem is PIT stops counting when it
  56 * hits zero.  If it would wrap, we could use it just like a decrementer.
  57 */
  58static inline u64 get_dec(void)
  59{
  60        if (IS_ENABLED(CONFIG_40x))
  61                return mfspr(SPRN_PIT);
  62
  63        return mfspr(SPRN_DEC);
  64}
  65
  66/*
  67 * Note: Book E and 4xx processors differ from other PowerPC processors
  68 * in when the decrementer generates its interrupt: on the 1 to 0
  69 * transition for Book E/4xx, but on the 0 to -1 transition for others.
  70 */
  71static inline void set_dec(u64 val)
  72{
  73        if (IS_ENABLED(CONFIG_40x))
  74                mtspr(SPRN_PIT, (u32)val);
  75        else if (IS_ENABLED(CONFIG_BOOKE))
  76                mtspr(SPRN_DEC, val);
  77        else
  78                mtspr(SPRN_DEC, val - 1);
  79}
  80
  81static inline unsigned long tb_ticks_since(unsigned long tstamp)
  82{
  83        return mftb() - tstamp;
  84}
  85
  86#define mulhwu(x,y) \
  87({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
  88
  89#ifdef CONFIG_PPC64
  90#define mulhdu(x,y) \
  91({unsigned long z; asm ("mulhdu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
  92#else
  93extern u64 mulhdu(u64, u64);
  94#endif
  95
  96extern void div128_by_32(u64 dividend_high, u64 dividend_low,
  97                         unsigned divisor, struct div_result *dr);
  98
  99extern void secondary_cpu_time_init(void);
 100extern void __init time_init(void);
 101
 102DECLARE_PER_CPU(u64, decrementers_next_tb);
 103
 104static inline u64 timer_get_next_tb(void)
 105{
 106        return __this_cpu_read(decrementers_next_tb);
 107}
 108
 109#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 110void timer_rearm_host_dec(u64 now);
 111#endif
 112
 113/* Convert timebase ticks to nanoseconds */
 114unsigned long long tb_to_ns(unsigned long long tb_ticks);
 115
 116void timer_broadcast_interrupt(void);
 117
 118/* SPLPAR */
 119void accumulate_stolen_time(void);
 120
 121#endif /* __KERNEL__ */
 122#endif /* __POWERPC_TIME_H */
 123