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. */ 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 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 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 void clock_comparator_work(void); 53 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 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 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 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 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 } 99 100 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 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 */ 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 */ 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