arch/s390/include/asm/timex.h

   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 #include <linux/time64.h>
  14
  15 /* The value of the TOD clock for 1.1.1970. */
  16 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
  17
  18 /* Inline functions for clock register access. */
  19 static inline int set_tod_clock(__u64 time)
  20 {
  21         int cc;
  22
  23         asm volatile(
  24                 "   sck   %1\n"
  25                 "   ipm   %0\n"
  26                 "   srl   %0,28\n"
  27                 : "=d" (cc) : "Q" (time) : "cc");
  28         return cc;
  29 }
  30
  31 static inline int store_tod_clock(__u64 *time)
  32 {
  33         int cc;
  34
  35         asm volatile(
  36                 "   stck  %1\n"
  37                 "   ipm   %0\n"
  38                 "   srl   %0,28\n"
  39                 : "=d" (cc), "=Q" (*time) : : "cc");
  40         return cc;
  41 }
  42
  43 static inline void set_clock_comparator(__u64 time)
  44 {
  45         asm volatile("sckc %0" : : "Q" (time));
  46 }
  47
  48 static inline void store_clock_comparator(__u64 *time)
  49 {
  50         asm volatile("stckc %0" : "=Q" (*time));
  51 }
  52
  53 void clock_comparator_work(void);
  54
  55 void __init ptff_init(void);
  56
  57 extern unsigned char ptff_function_mask[16];
  58 extern unsigned long lpar_offset;
  59
  60 /* Function codes for the ptff instruction. */
  61 #define PTFF_QAF        0x00    /* query available functions */
  62 #define PTFF_QTO        0x01    /* query tod offset */
  63 #define PTFF_QSI        0x02    /* query steering information */
  64 #define PTFF_ATO        0x40    /* adjust tod offset */
  65 #define PTFF_STO        0x41    /* set tod offset */
  66 #define PTFF_SFS        0x42    /* set fine steering rate */
  67 #define PTFF_SGS        0x43    /* set gross steering rate */
  68
  69 /* Query TOD offset result */
  70 struct ptff_qto {
  71         unsigned long long physical_clock;
  72         unsigned long long tod_offset;
  73         unsigned long long logical_tod_offset;
  74         unsigned long long tod_epoch_difference;
  75 } __packed;
  76
  77 static inline int ptff_query(unsigned int nr)
  78 {
  79         unsigned char *ptr;
  80
  81         ptr = ptff_function_mask + (nr >> 3);
  82         return (*ptr & (0x80 >> (nr & 7))) != 0;
  83 }
  84
  85 static inline int ptff(void *ptff_block, size_t len, unsigned int func)
  86 {
  87         typedef struct { char _[len]; } addrtype;
  88         register unsigned int reg0 asm("0") = func;
  89         register unsigned long reg1 asm("1") = (unsigned long) ptff_block;
  90         int rc;
  91
  92         asm volatile(
  93                 "       .word   0x0104\n"
  94                 "       ipm     %0\n"
  95                 "       srl     %0,28\n"
  96                 : "=d" (rc), "+m" (*(addrtype *) ptff_block)
  97                 : "d" (reg0), "d" (reg1) : "cc");
  98         return rc;
  99 }
 100
 101 static inline unsigned long long local_tick_disable(void)
 102 {
 103         unsigned long long old;
 104
 105         old = S390_lowcore.clock_comparator;
 106         S390_lowcore.clock_comparator = -1ULL;
 107         set_clock_comparator(S390_lowcore.clock_comparator);
 108         return old;
 109 }
 110
 111 static inline void local_tick_enable(unsigned long long comp)
 112 {
 113         S390_lowcore.clock_comparator = comp;
 114         set_clock_comparator(S390_lowcore.clock_comparator);
 115 }
 116
 117 #define CLOCK_TICK_RATE         1193180 /* Underlying HZ */
 118 #define STORE_CLOCK_EXT_SIZE    16      /* stcke writes 16 bytes */
 119
 120 typedef unsigned long long cycles_t;
 121
 122 static inline void get_tod_clock_ext(char *clk)
 123 {
 124         typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
 125
 126         asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
 127 }
 128
 129 static inline unsigned long long get_tod_clock(void)
 130 {
 131         unsigned char clk[STORE_CLOCK_EXT_SIZE];
 132
 133         get_tod_clock_ext(clk);
 134         return *((unsigned long long *)&clk[1]);
 135 }
 136
 137 static inline unsigned long long get_tod_clock_fast(void)
 138 {
 139 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 140         unsigned long long clk;
 141
 142         asm volatile("stckf %0" : "=Q" (clk) : : "cc");
 143         return clk;
 144 #else
 145         return get_tod_clock();
 146 #endif
 147 }
 148
 149 static inline cycles_t get_cycles(void)
 150 {
 151         return (cycles_t) get_tod_clock() >> 2;
 152 }
 153
 154 int get_phys_clock(unsigned long long *clock);
 155 void init_cpu_timer(void);
 156 unsigned long long monotonic_clock(void);
 157
 158 void tod_to_timeval(__u64 todval, struct timespec64 *xt);
 159
 160 static inline
 161 void stck_to_timespec64(unsigned long long stck, struct timespec64 *ts)
 162 {
 163         tod_to_timeval(stck - TOD_UNIX_EPOCH, ts);
 164 }
 165
 166 extern u64 sched_clock_base_cc;
 167
 168 /**
 169  * get_clock_monotonic - returns current time in clock rate units
 170  *
 171  * The caller must ensure that preemption is disabled.
 172  * The clock and sched_clock_base get changed via stop_machine.
 173  * Therefore preemption must be disabled when calling this
 174  * function, otherwise the returned value is not guaranteed to
 175  * be monotonic.
 176  */
 177 static inline unsigned long long get_tod_clock_monotonic(void)
 178 {
 179         return get_tod_clock() - sched_clock_base_cc;
 180 }
 181
 182 /**
 183  * tod_to_ns - convert a TOD format value to nanoseconds
 184  * @todval: to be converted TOD format value
 185  * Returns: number of nanoseconds that correspond to the TOD format value
 186  *
 187  * Converting a 64 Bit TOD format value to nanoseconds means that the value
 188  * must be divided by 4.096. In order to achieve that we multiply with 125
 189  * and divide by 512:
 190  *
 191  *    ns = (todval * 125) >> 9;
 192  *
 193  * In order to avoid an overflow with the multiplication we can rewrite this.
 194  * With a split todval == 2^32 * th + tl (th upper 32 bits, tl lower 32 bits)
 195  * we end up with
 196  *
 197  *    ns = ((2^32 * th + tl) * 125 ) >> 9;
 198  * -> ns = (2^23 * th * 125) + ((tl * 125) >> 9);
 199  *
 200  */
 201 static inline unsigned long long tod_to_ns(unsigned long long todval)
 202 {
 203         unsigned long long ns;
 204
 205         ns = ((todval >> 32) << 23) * 125;
 206         ns += ((todval & 0xffffffff) * 125) >> 9;
 207         return ns;
 208 }
 209
 210 #endif