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/types.h>
13#include <linux/rtc.h>
14#include <linux/threads.h>
15
16#include <asm/reg.h>
17
18/* time.c */
19extern unsigned tb_ticks_per_jiffy;
20extern unsigned tb_to_us;
21extern unsigned tb_last_stamp;
22extern unsigned long disarm_decr[NR_CPUS];
23
24extern void to_tm(int tim, struct rtc_time * tm);
25extern time_t last_rtc_update;
26
27extern void set_dec_cpu6(unsigned int val);
28
29int via_calibrate_decr(void);
30
31/* Accessor functions for the decrementer register.
32 * The 4xx doesn't even have a decrementer.  I tried to use the
33 * generic timer interrupt code, which seems OK, with the 4xx PIT
34 * in auto-reload mode.  The problem is PIT stops counting when it
35 * hits zero.  If it would wrap, we could use it just like a decrementer.
36 */
37static __inline__ unsigned int get_dec(void)
38{
39#if defined(CONFIG_40x)
40	return (mfspr(SPRN_PIT));
41#else
42	return (mfspr(SPRN_DEC));
43#endif
44}
45
46static __inline__ void set_dec(unsigned int val)
47{
48#if defined(CONFIG_40x)
49	return;		/* Have to let it auto-reload */
50#elif defined(CONFIG_8xx_CPU6)
51	set_dec_cpu6(val);
52#else
53	mtspr(SPRN_DEC, val);
54#endif
55}
56
57/* Accessor functions for the timebase (RTC on 601) registers. */
58/* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
59#ifdef CONFIG_6xx
60extern __inline__ int __attribute_pure__ __USE_RTC(void) {
61	return (mfspr(SPRN_PVR)>>16) == 1;
62}
63#else
64#define __USE_RTC() 0
65#endif
66
67extern __inline__ unsigned long get_tbl(void) {
68	unsigned long tbl;
69#if defined(CONFIG_403GCX)
70	asm volatile("mfspr %0, 0x3dd" : "=r" (tbl));
71#else
72	asm volatile("mftb %0" : "=r" (tbl));
73#endif
74	return tbl;
75}
76
77extern __inline__ unsigned long get_tbu(void) {
78	unsigned long tbl;
79#if defined(CONFIG_403GCX)
80	asm volatile("mfspr %0, 0x3dc" : "=r" (tbl));
81#else
82	asm volatile("mftbu %0" : "=r" (tbl));
83#endif
84	return tbl;
85}
86
87extern __inline__ void set_tb(unsigned int upper, unsigned int lower)
88{
89	mtspr(SPRN_TBWL, 0);
90	mtspr(SPRN_TBWU, upper);
91	mtspr(SPRN_TBWL, lower);
92}
93
94extern __inline__ unsigned long get_rtcl(void) {
95	unsigned long rtcl;
96	asm volatile("mfrtcl %0" : "=r" (rtcl));
97	return rtcl;
98}
99
100extern __inline__ unsigned long get_rtcu(void)
101{
102	unsigned long rtcu;
103	asm volatile("mfrtcu %0" : "=r" (rtcu));
104	return rtcu;
105}
106
107extern __inline__ unsigned get_native_tbl(void) {
108	if (__USE_RTC())
109		return get_rtcl();
110	else
111	  	return get_tbl();
112}
113
114/* On machines with RTC, this function can only be used safely
115 * after the timestamp and for 1 second. It is only used by gettimeofday
116 * however so it should not matter.
117 */
118extern __inline__ unsigned tb_ticks_since(unsigned tstamp) {
119	if (__USE_RTC()) {
120		int delta = get_rtcl() - tstamp;
121		return delta<0 ? delta + 1000000000 : delta;
122	} else {
123        	return get_tbl() - tstamp;
124	}
125}
126
127
128/* Use mulhwu to scale processor timebase to timeval */
129/* Specifically, this computes (x * y) / 2^32.  -- paulus */
130#define mulhwu(x,y) \
131({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
132
133unsigned mulhwu_scale_factor(unsigned, unsigned);
134
135#define account_process_vtime(tsk)		do { } while (0)
136#define calculate_steal_time()			do { } while (0)
137#define snapshot_timebases()			do { } while (0)
138
139#endif /* __ASM_TIME_H__ */
140#endif /* __KERNEL__ */
141