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 time_early_init(void);
  56
  57 extern unsigned char ptff_function_mask[16];
  58
  59 /* Function codes for the ptff instruction. */
  60 #define PTFF_QAF        0x00    /* query available functions */
  61 #define PTFF_QTO        0x01    /* query tod offset */
  62 #define PTFF_QSI        0x02    /* query steering information */
  63 #define PTFF_QUI        0x04    /* query UTC 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 /* Query UTC information result */
  86 struct ptff_qui {
  87         unsigned int tm : 2;
  88         unsigned int ts : 2;
  89         unsigned int : 28;
  90         unsigned int pad_0x04;
  91         unsigned long leap_event;
  92         short old_leap;
  93         short new_leap;
  94         unsigned int pad_0x14;
  95         unsigned long prt[5];
  96         unsigned long cst[3];
  97         unsigned int skew;
  98         unsigned int pad_0x5c[41];
  99 } __packed;
 100
 101 /*
 102  * ptff - Perform timing facility function
 103  * @ptff_block: Pointer to ptff parameter block
 104  * @len: Length of parameter block
 105  * @func: Function code
 106  * Returns: Condition code (0 on success)
 107  */
 108 #define ptff(ptff_block, len, func)                                     \
 109 ({                                                                      \
 110         struct addrtype { char _[len]; };                               \
 111         register unsigned int reg0 asm("0") = func;                     \
 112         register unsigned long reg1 asm("1") = (unsigned long) (ptff_block);\
 113         int rc;                                                         \
 114                                                                         \
 115         asm volatile(                                                   \
 116                 "       .word   0x0104\n"                               \
 117                 "       ipm     %0\n"                                   \
 118                 "       srl     %0,28\n"                                \
 119                 : "=d" (rc), "+m" (*(struct addrtype *) reg1)           \
 120                 : "d" (reg0), "d" (reg1) : "cc");                       \
 121         rc;                                                             \
 122 })
 123
 124 static inline unsigned long long local_tick_disable(void)
 125 {
 126         unsigned long long old;
 127
 128         old = S390_lowcore.clock_comparator;
 129         S390_lowcore.clock_comparator = -1ULL;
 130         set_clock_comparator(S390_lowcore.clock_comparator);
 131         return old;
 132 }
 133
 134 static inline void local_tick_enable(unsigned long long comp)
 135 {
 136         S390_lowcore.clock_comparator = comp;
 137         set_clock_comparator(S390_lowcore.clock_comparator);
 138 }
 139
 140 #define CLOCK_TICK_RATE         1193180 /* Underlying HZ */
 141 #define STORE_CLOCK_EXT_SIZE    16      /* stcke writes 16 bytes */
 142
 143 typedef unsigned long long cycles_t;
 144
 145 static inline void get_tod_clock_ext(char *clk)
 146 {
 147         typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
 148
 149         asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
 150 }
 151
 152 static inline unsigned long long get_tod_clock(void)
 153 {
 154         unsigned char clk[STORE_CLOCK_EXT_SIZE];
 155
 156         get_tod_clock_ext(clk);
 157         return *((unsigned long long *)&clk[1]);
 158 }
 159
 160 static inline unsigned long long get_tod_clock_fast(void)
 161 {
 162 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 163         unsigned long long clk;
 164
 165         asm volatile("stckf %0" : "=Q" (clk) : : "cc");
 166         return clk;
 167 #else
 168         return get_tod_clock();
 169 #endif
 170 }
 171
 172 static inline cycles_t get_cycles(void)
 173 {
 174         return (cycles_t) get_tod_clock() >> 2;
 175 }
 176
 177 int get_phys_clock(unsigned long long *clock);
 178 void init_cpu_timer(void);
 179 unsigned long long monotonic_clock(void);
 180
 181 extern u64 sched_clock_base_cc;
 182
 183 /**
 184  * get_clock_monotonic - returns current time in clock rate units
 185  *
 186  * The caller must ensure that preemption is disabled.
 187  * The clock and sched_clock_base get changed via stop_machine.
 188  * Therefore preemption must be disabled when calling this
 189  * function, otherwise the returned value is not guaranteed to
 190  * be monotonic.
 191  */
 192 static inline unsigned long long get_tod_clock_monotonic(void)
 193 {
 194         return get_tod_clock() - sched_clock_base_cc;
 195 }
 196
 197 /**
 198  * tod_to_ns - convert a TOD format value to nanoseconds
 199  * @todval: to be converted TOD format value
 200  * Returns: number of nanoseconds that correspond to the TOD format value
 201  *
 202  * Converting a 64 Bit TOD format value to nanoseconds means that the value
 203  * must be divided by 4.096. In order to achieve that we multiply with 125
 204  * and divide by 512:
 205  *
 206  *    ns = (todval * 125) >> 9;
 207  *
 208  * In order to avoid an overflow with the multiplication we can rewrite this.
 209  * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
 210  * we end up with
 211  *
 212  *    ns = ((2^9 * th + tl) * 125 ) >> 9;
 213  * -> ns = (th * 125) + ((tl * 125) >> 9);
 214  *
 215  */
 216 static inline unsigned long long tod_to_ns(unsigned long long todval)
 217 {
 218         return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
 219 }
 220
 221 #endif