1 /*
2 * S390 version
3 * Copyright IBM Corp. 1999
4 *
5 * Derived from "include/asm-i386/timex.h"
6 * Copyright (C) 1992, Linus Torvalds
7 */
8
9 #ifndef _ASM_S390_TIMEX_H
10 #define _ASM_S390_TIMEX_H
11
12 #include <asm/lowcore.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. */
set_tod_clock(__u64 time)18 static inline int set_tod_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
store_tod_clock(__u64 * time)30 static inline int store_tod_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
set_clock_comparator(__u64 time)42 static inline void set_clock_comparator(__u64 time)
43 {
44 asm volatile("sckc %0" : : "Q" (time));
45 }
46
store_clock_comparator(__u64 * time)47 static inline void store_clock_comparator(__u64 *time)
48 {
49 asm volatile("stckc %0" : "=Q" (*time));
50 }
51
52 void clock_comparator_work(void);
53
local_tick_disable(void)54 static inline unsigned long long local_tick_disable(void)
55 {
56 unsigned long long old;
57
58 old = S390_lowcore.clock_comparator;
59 S390_lowcore.clock_comparator = -1ULL;
60 set_clock_comparator(S390_lowcore.clock_comparator);
61 return old;
62 }
63
local_tick_enable(unsigned long long comp)64 static inline void local_tick_enable(unsigned long long comp)
65 {
66 S390_lowcore.clock_comparator = comp;
67 set_clock_comparator(S390_lowcore.clock_comparator);
68 }
69
70 #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
71
72 typedef unsigned long long cycles_t;
73
get_tod_clock(void)74 static inline unsigned long long get_tod_clock(void)
75 {
76 unsigned long long clk;
77
78 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
79 asm volatile(".insn s,0xb27c0000,%0" : "=Q" (clk) : : "cc");
80 #else
81 asm volatile("stck %0" : "=Q" (clk) : : "cc");
82 #endif
83 return clk;
84 }
85
get_tod_clock_ext(char * clk)86 static inline void get_tod_clock_ext(char *clk)
87 {
88 asm volatile("stcke %0" : "=Q" (*clk) : : "cc");
89 }
90
get_tod_clock_xt(void)91 static inline unsigned long long get_tod_clock_xt(void)
92 {
93 unsigned char clk[16];
94 get_tod_clock_ext(clk);
95 return *((unsigned long long *)&clk[1]);
96 }
97
get_cycles(void)98 static inline cycles_t get_cycles(void)
99 {
100 return (cycles_t) get_tod_clock() >> 2;
101 }
102
103 int get_sync_clock(unsigned long long *clock);
104 void init_cpu_timer(void);
105 unsigned long long monotonic_clock(void);
106
107 void tod_to_timeval(__u64, struct timespec *);
108
109 static inline
stck_to_timespec(unsigned long long stck,struct timespec * ts)110 void stck_to_timespec(unsigned long long stck, struct timespec *ts)
111 {
112 tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
113 }
114
115 extern u64 sched_clock_base_cc;
116
117 /**
118 * get_clock_monotonic - returns current time in clock rate units
119 *
120 * The caller must ensure that preemption is disabled.
121 * The clock and sched_clock_base get changed via stop_machine.
122 * Therefore preemption must be disabled when calling this
123 * function, otherwise the returned value is not guaranteed to
124 * be monotonic.
125 */
get_tod_clock_monotonic(void)126 static inline unsigned long long get_tod_clock_monotonic(void)
127 {
128 return get_tod_clock_xt() - sched_clock_base_cc;
129 }
130
131 /**
132 * tod_to_ns - convert a TOD format value to nanoseconds
133 * @todval: to be converted TOD format value
134 * Returns: number of nanoseconds that correspond to the TOD format value
135 *
136 * Converting a 64 Bit TOD format value to nanoseconds means that the value
137 * must be divided by 4.096. In order to achieve that we multiply with 125
138 * and divide by 512:
139 *
140 * ns = (todval * 125) >> 9;
141 *
142 * In order to avoid an overflow with the multiplication we can rewrite this.
143 * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits)
144 * we end up with
145 *
146 * ns = ((2^32 * th + tl) * 125 ) >> 9;
147 * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9);
148 *
149 */
tod_to_ns(unsigned long long todval)150 static inline unsigned long long tod_to_ns(unsigned long long todval)
151 {
152 unsigned long long ns;
153
154 ns = ((todval >> 32) << 23) * 125;
155 ns += ((todval & 0xffffffff) * 125) >> 9;
156 return ns;
157 }
158
159 #endif
160