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