arch/s390/include/asm/timex.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  S390 version
   4  *    Copyright IBM Corp. 1999
   5  *
   6  *  Derived from "include/asm-i386/timex.h"
   7  *    Copyright (C) 1992, Linus Torvalds
   8  */
   9
  10 #ifndef _ASM_S390_TIMEX_H
  11 #define _ASM_S390_TIMEX_H
  12
  13 #include <linux/preempt.h>
  14 #include <linux/time64.h>
  15 #include <asm/lowcore.h>
  16
  17 /* The value of the TOD clock for 1.1.1970. */
  18 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
  19
  20 extern u64 clock_comparator_max;
  21
  22 /* Inline functions for clock register access. */
  23 static inline int set_tod_clock(__u64 time)
  24 {
  25         int cc;
  26
  27         asm volatile(
  28                 "   sck   %1\n"
  29                 "   ipm   %0\n"
  30                 "   srl   %0,28\n"
  31                 : "=d" (cc) : "Q" (time) : "cc");
  32         return cc;
  33 }
  34
  35 static inline int store_tod_clock(__u64 *time)
  36 {
  37         int cc;
  38
  39         asm volatile(
  40                 "   stck  %1\n"
  41                 "   ipm   %0\n"
  42                 "   srl   %0,28\n"
  43                 : "=d" (cc), "=Q" (*time) : : "cc");
  44         return cc;
  45 }
  46
  47 static inline void set_clock_comparator(__u64 time)
  48 {
  49         asm volatile("sckc %0" : : "Q" (time));
  50 }
  51
  52 static inline void set_tod_programmable_field(u16 val)
  53 {
  54         register unsigned long reg0 asm("0") = val;
  55
  56         asm volatile("sckpf" : : "d" (reg0));
  57 }
  58
  59 void clock_comparator_work(void);
  60
  61 void __init time_early_init(void);
  62
  63 extern unsigned char ptff_function_mask[16];
  64
  65 /* Function codes for the ptff instruction. */
  66 #define PTFF_QAF        0x00    /* query available functions */
  67 #define PTFF_QTO        0x01    /* query tod offset */
  68 #define PTFF_QSI        0x02    /* query steering information */
  69 #define PTFF_QUI        0x04    /* query UTC information */
  70 #define PTFF_ATO        0x40    /* adjust tod offset */
  71 #define PTFF_STO        0x41    /* set tod offset */
  72 #define PTFF_SFS        0x42    /* set fine steering rate */
  73 #define PTFF_SGS        0x43    /* set gross steering rate */
  74
  75 /* Query TOD offset result */
  76 struct ptff_qto {
  77         unsigned long long physical_clock;
  78         unsigned long long tod_offset;
  79         unsigned long long logical_tod_offset;
  80         unsigned long long tod_epoch_difference;
  81 } __packed;
  82
  83 static inline int ptff_query(unsigned int nr)
  84 {
  85         unsigned char *ptr;
  86
  87         ptr = ptff_function_mask + (nr >> 3);
  88         return (*ptr & (0x80 >> (nr & 7))) != 0;
  89 }
  90
  91 /* Query UTC information result */
  92 struct ptff_qui {
  93         unsigned int tm : 2;
  94         unsigned int ts : 2;
  95         unsigned int : 28;
  96         unsigned int pad_0x04;
  97         unsigned long leap_event;
  98         short old_leap;
  99         short new_leap;
 100         unsigned int pad_0x14;
 101         unsigned long prt[5];
 102         unsigned long cst[3];
 103         unsigned int skew;
 104         unsigned int pad_0x5c[41];
 105 } __packed;
 106
 107 /*
 108  * ptff - Perform timing facility function
 109  * @ptff_block: Pointer to ptff parameter block
 110  * @len: Length of parameter block
 111  * @func: Function code
 112  * Returns: Condition code (0 on success)
 113  */
 114 #define ptff(ptff_block, len, func)                                     \
 115 ({                                                                      \
 116         struct addrtype { char _[len]; };                               \
 117         register unsigned int reg0 asm("0") = func;                     \
 118         register unsigned long reg1 asm("1") = (unsigned long) (ptff_block);\
 119         int rc;                                                         \
 120                                                                         \
 121         asm volatile(                                                   \
 122                 "       .word   0x0104\n"                               \
 123                 "       ipm     %0\n"                                   \
 124                 "       srl     %0,28\n"                                \
 125                 : "=d" (rc), "+m" (*(struct addrtype *) reg1)           \
 126                 : "d" (reg0), "d" (reg1) : "cc");                       \
 127         rc;                                                             \
 128 })
 129
 130 static inline unsigned long long local_tick_disable(void)
 131 {
 132         unsigned long long old;
 133
 134         old = S390_lowcore.clock_comparator;
 135         S390_lowcore.clock_comparator = clock_comparator_max;
 136         set_clock_comparator(S390_lowcore.clock_comparator);
 137         return old;
 138 }
 139
 140 static inline void local_tick_enable(unsigned long long comp)
 141 {
 142         S390_lowcore.clock_comparator = comp;
 143         set_clock_comparator(S390_lowcore.clock_comparator);
 144 }
 145
 146 #define CLOCK_TICK_RATE         1193180 /* Underlying HZ */
 147 #define STORE_CLOCK_EXT_SIZE    16      /* stcke writes 16 bytes */
 148
 149 typedef unsigned long long cycles_t;
 150
 151 static inline void get_tod_clock_ext(char *clk)
 152 {
 153         typedef struct { char _[STORE_CLOCK_EXT_SIZE]; } addrtype;
 154
 155         asm volatile("stcke %0" : "=Q" (*(addrtype *) clk) : : "cc");
 156 }
 157
 158 static inline unsigned long long get_tod_clock(void)
 159 {
 160         char clk[STORE_CLOCK_EXT_SIZE];
 161
 162         get_tod_clock_ext(clk);
 163         return *((unsigned long long *)&clk[1]);
 164 }
 165
 166 static inline unsigned long long get_tod_clock_fast(void)
 167 {
 168 #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
 169         unsigned long long clk;
 170
 171         asm volatile("stckf %0" : "=Q" (clk) : : "cc");
 172         return clk;
 173 #else
 174         return get_tod_clock();
 175 #endif
 176 }
 177
 178 static inline cycles_t get_cycles(void)
 179 {
 180         return (cycles_t) get_tod_clock() >> 2;
 181 }
 182
 183 int get_phys_clock(unsigned long *clock);
 184 void init_cpu_timer(void);
 185
 186 extern unsigned char tod_clock_base[16] __aligned(8);
 187
 188 /**
 189  * get_clock_monotonic - returns current time in clock rate units
 190  *
 191  * The clock and tod_clock_base get changed via stop_machine.
 192  * Therefore preemption must be disabled, otherwise the returned
 193  * value is not guaranteed to be monotonic.
 194  */
 195 static inline unsigned long long get_tod_clock_monotonic(void)
 196 {
 197         unsigned long long tod;
 198
 199         preempt_disable_notrace();
 200         tod = get_tod_clock() - *(unsigned long long *) &tod_clock_base[1];
 201         preempt_enable_notrace();
 202         return tod;
 203 }
 204
 205 /**
 206  * tod_to_ns - convert a TOD format value to nanoseconds
 207  * @todval: to be converted TOD format value
 208  * Returns: number of nanoseconds that correspond to the TOD format value
 209  *
 210  * Converting a 64 Bit TOD format value to nanoseconds means that the value
 211  * must be divided by 4.096. In order to achieve that we multiply with 125
 212  * and divide by 512:
 213  *
 214  *    ns = (todval * 125) >> 9;
 215  *
 216  * In order to avoid an overflow with the multiplication we can rewrite this.
 217  * With a split todval == 2^9 * th + tl (th upper 55 bits, tl lower 9 bits)
 218  * we end up with
 219  *
 220  *    ns = ((2^9 * th + tl) * 125 ) >> 9;
 221  * -> ns = (th * 125) + ((tl * 125) >> 9);
 222  *
 223  */
 224 static inline unsigned long long tod_to_ns(unsigned long long todval)
 225 {
 226         return ((todval >> 9) * 125) + (((todval & 0x1ff) * 125) >> 9);
 227 }
 228
 229 /**
 230  * tod_after - compare two 64 bit TOD values
 231  * @a: first 64 bit TOD timestamp
 232  * @b: second 64 bit TOD timestamp
 233  *
 234  * Returns: true if a is later than b
 235  */
 236 static inline int tod_after(unsigned long long a, unsigned long long b)
 237 {
 238         if (MACHINE_HAS_SCC)
 239                 return (long long) a > (long long) b;
 240         return a > b;
 241 }
 242
 243 /**
 244  * tod_after_eq - compare two 64 bit TOD values
 245  * @a: first 64 bit TOD timestamp
 246  * @b: second 64 bit TOD timestamp
 247  *
 248  * Returns: true if a is later than b
 249  */
 250 static inline int tod_after_eq(unsigned long long a, unsigned long long b)
 251 {
 252         if (MACHINE_HAS_SCC)
 253                 return (long long) a >= (long long) b;
 254         return a >= b;
 255 }
 256
 257 #endif