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