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;
 27extern u64 decrementer_max;
 28
 29
 30extern void generic_calibrate_decr(void);
 31
 32#ifdef CONFIG_PPC_SPLPAR
 33extern u64 get_boot_tb(void);
 34#endif
 35
 36/* Some sane defaults: 125 MHz timebase, 1GHz processor */
 37extern unsigned long ppc_proc_freq;
 38#define DEFAULT_PROC_FREQ	(DEFAULT_TB_FREQ * 8)
 39extern unsigned long ppc_tb_freq;
 40#define DEFAULT_TB_FREQ		125000000UL
 41
 42extern bool tb_invalid;
 43
 44struct div_result {
 45	u64 result_high;
 46	u64 result_low;
 47};
 48
 49static inline u64 get_vtb(void)
 50{
 51	if (cpu_has_feature(CPU_FTR_ARCH_207S))
 52		return mfspr(SPRN_VTB);
 53
 54	return 0;
 55}
 56
 57/* Accessor functions for the decrementer register.
 58 * The 4xx doesn't even have a decrementer.  I tried to use the
 59 * generic timer interrupt code, which seems OK, with the 4xx PIT
 60 * in auto-reload mode.  The problem is PIT stops counting when it
 61 * hits zero.  If it would wrap, we could use it just like a decrementer.
 62 */
 63static inline u64 get_dec(void)
 64{
 65	return mfspr(SPRN_DEC);
 66}
 67
 68/*
 69 * Note: Book E and 4xx processors differ from other PowerPC processors
 70 * in when the decrementer generates its interrupt: on the 1 to 0
 71 * transition for Book E/4xx, but on the 0 to -1 transition for others.
 72 */
 73static inline void set_dec(u64 val)
 74{
 75	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
 93#define mulhdu(x, y)	mul_u64_u64_shr(x, y, 64)
 94#endif
 95
 96extern void secondary_cpu_time_init(void);
 97extern void __init time_init(void);
 98
 99DECLARE_PER_CPU(u64, decrementers_next_tb);
100
101static inline u64 timer_get_next_tb(void)
102{
103	return __this_cpu_read(decrementers_next_tb);
104}
105
106#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
107void timer_rearm_host_dec(u64 now);
108#endif
109
110/* Convert timebase ticks to nanoseconds */
111unsigned long long tb_to_ns(unsigned long long tb_ticks);
112
113void timer_broadcast_interrupt(void);
114
115/* SPLPAR and VIRT_CPU_ACCOUNTING_NATIVE */
116void pseries_accumulate_stolen_time(void);
117u64 pseries_calculate_stolen_time(u64 stop_tb);
118
119#endif /* __KERNEL__ */
120#endif /* __POWERPC_TIME_H */