xref: /openbmc/linux/arch/s390/include/asm/timex.h (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  *  include/asm-s390/timex.h
3  *
4  *  S390 version
5  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *
7  *  Derived from "include/asm-i386/timex.h"
8  *    Copyright (C) 1992, Linus Torvalds
9  */
10 
11 #ifndef _ASM_S390_TIMEX_H
12 #define _ASM_S390_TIMEX_H
13 
14 /* The value of the TOD clock for 1.1.1970. */
15 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
16 
17 /* Inline functions for clock register access. */
18 static inline int set_clock(__u64 time)
19 {
20 	int cc;
21 
22 	asm volatile(
23 		"   sck   %1\n"
24 		"   ipm   %0\n"
25 		"   srl   %0,28\n"
26 		: "=d" (cc) : "Q" (time) : "cc");
27 	return cc;
28 }
29 
30 static inline int store_clock(__u64 *time)
31 {
32 	int cc;
33 
34 	asm volatile(
35 		"   stck  %1\n"
36 		"   ipm   %0\n"
37 		"   srl   %0,28\n"
38 		: "=d" (cc), "=Q" (*time) : : "cc");
39 	return cc;
40 }
41 
42 static inline void set_clock_comparator(__u64 time)
43 {
44 	asm volatile("sckc %0" : : "Q" (time));
45 }
46 
47 static inline void store_clock_comparator(__u64 *time)
48 {
49 	asm volatile("stckc %0" : "=Q" (*time));
50 }
51 
52 #define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
53 
54 typedef unsigned long long cycles_t;
55 
56 static inline unsigned long long get_clock (void)
57 {
58 	unsigned long long clk;
59 
60 	asm volatile("stck %0" : "=Q" (clk) : : "cc");
61 	return clk;
62 }
63 
64 static inline void get_clock_ext(char *clk)
65 {
66 	asm volatile("stcke %0" : "=Q" (*clk) : : "cc");
67 }
68 
69 static inline unsigned long long get_clock_xt(void)
70 {
71 	unsigned char clk[16];
72 	get_clock_ext(clk);
73 	return *((unsigned long long *)&clk[1]);
74 }
75 
76 static inline cycles_t get_cycles(void)
77 {
78 	return (cycles_t) get_clock() >> 2;
79 }
80 
81 int get_sync_clock(unsigned long long *clock);
82 void init_cpu_timer(void);
83 unsigned long long monotonic_clock(void);
84 
85 void tod_to_timeval(__u64, struct timespec *);
86 
87 static inline
88 void stck_to_timespec(unsigned long long stck, struct timespec *ts)
89 {
90 	tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
91 }
92 
93 extern u64 sched_clock_base_cc;
94 
95 /**
96  * get_clock_monotonic - returns current time in clock rate units
97  *
98  * The caller must ensure that preemption is disabled.
99  * The clock and sched_clock_base get changed via stop_machine.
100  * Therefore preemption must be disabled when calling this
101  * function, otherwise the returned value is not guaranteed to
102  * be monotonic.
103  */
104 static inline unsigned long long get_clock_monotonic(void)
105 {
106 	return get_clock_xt() - sched_clock_base_cc;
107 }
108 
109 #endif
110