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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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 */