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_ext(char clk[16])74 static inline void get_tod_clock_ext(char clk[16])
75 {
76 typedef struct { char _[sizeof(clk)]; } addrtype;
77
78 asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
79 }
80
get_tod_clock(void)81 static inline unsigned long long get_tod_clock(void)
82 {
83 unsigned char clk[16];
84 get_tod_clock_ext(clk);
85 return *((unsigned long long *)&clk[1]);
86 }
87
get_tod_clock_fast(void)88 static inline unsigned long long get_tod_clock_fast(void)
89 {
90 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
91 unsigned long long clk;
92
93 asm volatile("stckf %0" : "=Q" (clk) : : "cc");
94 return clk;
95 #else
96 return get_tod_clock();
97 #endif
98 }
99
get_cycles(void)100 static inline cycles_t get_cycles(void)
101 {
102 return (cycles_t) get_tod_clock() >> 2;
103 }
104
105 int get_sync_clock(unsigned long long *clock);
106 void init_cpu_timer(void);
107 unsigned long long monotonic_clock(void);
108
109 void tod_to_timeval(__u64, struct timespec *);
110
111 static inline
stck_to_timespec(unsigned long long stck,struct timespec * ts)112 void stck_to_timespec(unsigned long long stck, struct timespec *ts)
113 {
114 tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
115 }
116
117 extern u64 sched_clock_base_cc;
118
119 /**
120 * get_clock_monotonic - returns current time in clock rate units
121 *
122 * The caller must ensure that preemption is disabled.
123 * The clock and sched_clock_base get changed via stop_machine.
124 * Therefore preemption must be disabled when calling this
125 * function, otherwise the returned value is not guaranteed to
126 * be monotonic.
127 */
get_tod_clock_monotonic(void)128 static inline unsigned long long get_tod_clock_monotonic(void)
129 {
130 return get_tod_clock() - sched_clock_base_cc;
131 }
132
133 /**
134 * tod_to_ns - convert a TOD format value to nanoseconds
135 * @todval: to be converted TOD format value
136 * Returns: number of nanoseconds that correspond to the TOD format value
137 *
138 * Converting a 64 Bit TOD format value to nanoseconds means that the value
139 * must be divided by 4.096. In order to achieve that we multiply with 125
140 * and divide by 512:
141 *
142 * ns = (todval * 125) >> 9;
143 *
144 * In order to avoid an overflow with the multiplication we can rewrite this.
145 * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits)
146 * we end up with
147 *
148 * ns = ((2^32 * th + tl) * 125 ) >> 9;
149 * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9);
150 *
151 */
tod_to_ns(unsigned long long todval)152 static inline unsigned long long tod_to_ns(unsigned long long todval)
153 {
154 unsigned long long ns;
155
156 ns = ((todval >> 32) << 23) * 125;
157 ns += ((todval & 0xffffffff) * 125) >> 9;
158 return ns;
159 }
160
161 #endif
162