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 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 86 static inline void get_tod_clock_ext(char *clk) 87 { 88 asm volatile("stcke %0" : "=Q" (*clk) : : "cc"); 89 } 90 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 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 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 */ 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 */ 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