3 * Copyright IBM Corp. 1999
5 * Derived from "include/asm-i386/timex.h"
6 * Copyright (C) 1992, Linus Torvalds
9 #ifndef _ASM_S390_TIMEX_H
10 #define _ASM_S390_TIMEX_H
12 #include <asm/lowcore.h>
14 /* The value of the TOD clock for 1.1.1970. */
15 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
17 /* Inline functions for clock register access. */
18 static inline int set_tod_clock(__u64 time)
26 : "=d" (cc) : "Q" (time) : "cc");
30 static inline int store_tod_clock(__u64 *time)
38 : "=d" (cc), "=Q" (*time) : : "cc");
42 static inline void set_clock_comparator(__u64 time)
44 asm volatile("sckc %0" : : "Q" (time));
47 static inline void store_clock_comparator(__u64 *time)
49 asm volatile("stckc %0" : "=Q" (*time));
52 void clock_comparator_work(void);
54 static inline unsigned long long local_tick_disable(void)
56 unsigned long long old;
58 old = S390_lowcore.clock_comparator;
59 S390_lowcore.clock_comparator = -1ULL;
60 set_clock_comparator(S390_lowcore.clock_comparator);
64 static inline void local_tick_enable(unsigned long long comp)
66 S390_lowcore.clock_comparator = comp;
67 set_clock_comparator(S390_lowcore.clock_comparator);
70 #define CLOCK_TICK_RATE 1193180 /* Underlying HZ */
71 #define STORE_CLOCK_EXT_SIZE 16 /* stcke writes 16 bytes */
73 typedef unsigned long long cycles_t;
75 static inline void get_tod_clock_ext(char *clk)
77 typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
79 asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
82 static inline unsigned long long get_tod_clock(void)
84 unsigned char clk[STORE_CLOCK_EXT_SIZE];
86 get_tod_clock_ext(clk);
87 return *((unsigned long long *)&clk[1]);
90 static inline unsigned long long get_tod_clock_fast(void)
92 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
93 unsigned long long clk;
95 asm volatile("stckf %0" : "=Q" (clk) : : "cc");
98 return get_tod_clock();
102 static inline cycles_t get_cycles(void)
104 return (cycles_t) get_tod_clock() >> 2;
107 int get_sync_clock(unsigned long long *clock);
108 void init_cpu_timer(void);
109 unsigned long long monotonic_clock(void);
111 void tod_to_timeval(__u64, struct timespec *);
114 void stck_to_timespec(unsigned long long stck, struct timespec *ts)
116 tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
119 extern u64 sched_clock_base_cc;
122 * get_clock_monotonic - returns current time in clock rate units
124 * The caller must ensure that preemption is disabled.
125 * The clock and sched_clock_base get changed via stop_machine.
126 * Therefore preemption must be disabled when calling this
127 * function, otherwise the returned value is not guaranteed to
130 static inline unsigned long long get_tod_clock_monotonic(void)
132 return get_tod_clock() - sched_clock_base_cc;
136 * tod_to_ns - convert a TOD format value to nanoseconds
137 * @todval: to be converted TOD format value
138 * Returns: number of nanoseconds that correspond to the TOD format value
140 * Converting a 64 Bit TOD format value to nanoseconds means that the value
141 * must be divided by 4.096. In order to achieve that we multiply with 125
144 * ns = (todval * 125) >> 9;
146 * In order to avoid an overflow with the multiplication we can rewrite this.
147 * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits)
150 * ns = ((2^32 * th + tl) * 125 ) >> 9;
151 * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9);
154 static inline unsigned long long tod_to_ns(unsigned long long todval)
156 unsigned long long ns;
158 ns = ((todval >> 32) << 23) * 125;
159 ns += ((todval & 0xffffffff) * 125) >> 9;