tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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_PPC_BOOK3S_32
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 */