Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Common time prototypes and such for all ppc machines.
3 *
4 * Written by Cort Dougan (cort@fsmlabs.com) to merge
5 * Paul Mackerras' version and mine for PReP and Pmac.
6 */
7
8#ifdef __KERNEL__
9#ifndef __ASM_TIME_H__
10#define __ASM_TIME_H__
11
12#include <linux/config.h>
13#include <linux/types.h>
14#include <linux/rtc.h>
15#include <linux/threads.h>
16
17#include <asm/reg.h>
18
19/* time.c */
20extern unsigned tb_ticks_per_jiffy;
21extern unsigned tb_to_us;
22extern unsigned tb_last_stamp;
23extern unsigned long disarm_decr[NR_CPUS];
24
25extern void to_tm(int tim, struct rtc_time * tm);
26extern time_t last_rtc_update;
27
28extern void set_dec_cpu6(unsigned int val);
29
30int via_calibrate_decr(void);
31
32/* Accessor functions for the decrementer register.
33 * The 4xx doesn't even have a decrementer. I tried to use the
34 * generic timer interrupt code, which seems OK, with the 4xx PIT
35 * in auto-reload mode. The problem is PIT stops counting when it
36 * hits zero. If it would wrap, we could use it just like a decrementer.
37 */
38static __inline__ unsigned int get_dec(void)
39{
40#if defined(CONFIG_40x)
41 return (mfspr(SPRN_PIT));
42#else
43 return (mfspr(SPRN_DEC));
44#endif
45}
46
47static __inline__ void set_dec(unsigned int val)
48{
49#if defined(CONFIG_40x)
50 return; /* Have to let it auto-reload */
51#elif defined(CONFIG_8xx_CPU6)
52 set_dec_cpu6(val);
53#else
54 mtspr(SPRN_DEC, val);
55#endif
56}
57
58/* Accessor functions for the timebase (RTC on 601) registers. */
59/* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
60#ifdef CONFIG_6xx
61extern __inline__ int __attribute_pure__ __USE_RTC(void) {
62 return (mfspr(SPRN_PVR)>>16) == 1;
63}
64#else
65#define __USE_RTC() 0
66#endif
67
68extern __inline__ unsigned long get_tbl(void) {
69 unsigned long tbl;
70#if defined(CONFIG_403GCX)
71 asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
72#else
73 asm volatile("mftb %0" : "=r" (tbl));
74#endif
75 return tbl;
76}
77
78extern __inline__ unsigned long get_tbu(void) {
79 unsigned long tbl;
80#if defined(CONFIG_403GCX)
81 asm volatile("mfspr %0, 0x3dc" : "=r" (tbl));
82#else
83 asm volatile("mftbu %0" : "=r" (tbl));
84#endif
85 return tbl;
86}
87
88extern __inline__ void set_tb(unsigned int upper, unsigned int lower)
89{
90 mtspr(SPRN_TBWL, 0);
91 mtspr(SPRN_TBWU, upper);
92 mtspr(SPRN_TBWL, lower);
93}
94
95extern __inline__ unsigned long get_rtcl(void) {
96 unsigned long rtcl;
97 asm volatile("mfrtcl %0" : "=r" (rtcl));
98 return rtcl;
99}
100
101extern __inline__ unsigned long get_rtcu(void)
102{
103 unsigned long rtcu;
104 asm volatile("mfrtcu %0" : "=r" (rtcu));
105 return rtcu;
106}
107
108extern __inline__ unsigned get_native_tbl(void) {
109 if (__USE_RTC())
110 return get_rtcl();
111 else
112 return get_tbl();
113}
114
115/* On machines with RTC, this function can only be used safely
116 * after the timestamp and for 1 second. It is only used by gettimeofday
117 * however so it should not matter.
118 */
119extern __inline__ unsigned tb_ticks_since(unsigned tstamp) {
120 if (__USE_RTC()) {
121 int delta = get_rtcl() - tstamp;
122 return delta<0 ? delta + 1000000000 : delta;
123 } else {
124 return get_tbl() - tstamp;
125 }
126}
127
128#if 0
129extern __inline__ unsigned long get_bin_rtcl(void) {
130 unsigned long rtcl, rtcu1, rtcu2;
131 asm volatile("\
1321: mfrtcu %0\n\
133 mfrtcl %1\n\
134 mfrtcu %2\n\
135 cmpw %0,%2\n\
136 bne- 1b\n"
137 : "=r" (rtcu1), "=r" (rtcl), "=r" (rtcu2)
138 : : "cr0");
139 return rtcu2*1000000000+rtcl;
140}
141
142extern __inline__ unsigned binary_tbl(void) {
143 if (__USE_RTC())
144 return get_bin_rtcl();
145 else
146 return get_tbl();
147}
148#endif
149
150/* Use mulhwu to scale processor timebase to timeval */
151/* Specifically, this computes (x * y) / 2^32. -- paulus */
152#define mulhwu(x,y) \
153({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
154
155unsigned mulhwu_scale_factor(unsigned, unsigned);
156#endif /* __ASM_TIME_H__ */
157#endif /* __KERNEL__ */