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 #include <asm/lowcore.h>
15 
16 /* The value of the TOD clock for 1.1.1970. */
17 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
18 
19 /* Inline functions for clock register access. */
set_clock(__u64 time)20 static inline int set_clock(__u64 time)
21 {
22 	int cc;
23 
24 	asm volatile(
25 		"   sck   %1\n"
26 		"   ipm   %0\n"
27 		"   srl   %0,28\n"
28 		: "=d" (cc) : "Q" (time) : "cc");
29 	return cc;
30 }
31 
store_clock(__u64 * time)32 static inline int store_clock(__u64 *time)
33 {
34 	int cc;
35 
36 	asm volatile(
37 		"   stck  %1\n"
38 		"   ipm   %0\n"
39 		"   srl   %0,28\n"
40 		: "=d" (cc), "=Q" (*time) : : "cc");
41 	return cc;
42 }
43 
set_clock_comparator(__u64 time)44 static inline void set_clock_comparator(__u64 time)
45 {
46 	asm volatile("sckc %0" : : "Q" (time));
47 }
48 
store_clock_comparator(__u64 * time)49 static inline void store_clock_comparator(__u64 *time)
50 {
51 	asm volatile("stckc %0" : "=Q" (*time));
52 }
53 
54 void clock_comparator_work(void);
55 
local_tick_disable(void)56 static inline unsigned long long local_tick_disable(void)
57 {
58 	unsigned long long old;
59 
60 	old = S390_lowcore.clock_comparator;
61 	S390_lowcore.clock_comparator = -1ULL;
62 	set_clock_comparator(S390_lowcore.clock_comparator);
63 	return old;
64 }
65 
local_tick_enable(unsigned long long comp)66 static inline void local_tick_enable(unsigned long long comp)
67 {
68 	S390_lowcore.clock_comparator = comp;
69 	set_clock_comparator(S390_lowcore.clock_comparator);
70 }
71 
72 #define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
73 
74 typedef unsigned long long cycles_t;
75 
get_clock(void)76 static inline unsigned long long get_clock (void)
77 {
78 	unsigned long long clk;
79 
80 	asm volatile("stck %0" : "=Q" (clk) : : "cc");
81 	return clk;
82 }
83 
get_clock_ext(char * clk)84 static inline void get_clock_ext(char *clk)
85 {
86 	asm volatile("stcke %0" : "=Q" (*clk) : : "cc");
87 }
88 
get_clock_xt(void)89 static inline unsigned long long get_clock_xt(void)
90 {
91 	unsigned char clk[16];
92 	get_clock_ext(clk);
93 	return *((unsigned long long *)&clk[1]);
94 }
95 
get_cycles(void)96 static inline cycles_t get_cycles(void)
97 {
98 	return (cycles_t) get_clock() >> 2;
99 }
100 
101 int get_sync_clock(unsigned long long *clock);
102 void init_cpu_timer(void);
103 unsigned long long monotonic_clock(void);
104 
105 void tod_to_timeval(__u64, struct timespec *);
106 
107 static inline
stck_to_timespec(unsigned long long stck,struct timespec * ts)108 void stck_to_timespec(unsigned long long stck, struct timespec *ts)
109 {
110 	tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
111 }
112 
113 extern u64 sched_clock_base_cc;
114 
115 /**
116  * get_clock_monotonic - returns current time in clock rate units
117  *
118  * The caller must ensure that preemption is disabled.
119  * The clock and sched_clock_base get changed via stop_machine.
120  * Therefore preemption must be disabled when calling this
121  * function, otherwise the returned value is not guaranteed to
122  * be monotonic.
123  */
get_clock_monotonic(void)124 static inline unsigned long long get_clock_monotonic(void)
125 {
126 	return get_clock_xt() - sched_clock_base_cc;
127 }
128 
129 #endif
130