LXR linux/arch/powerpc/include/asm/timex.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_POWERPC_TIMEX_H
   3#define _ASM_POWERPC_TIMEX_H
   4
   5#ifdef __KERNEL__
   6
   7/*
   8 * PowerPC architecture timex specifications
   9 */
  10
  11#include <asm/cputable.h>
  12#include <asm/reg.h>
  13
  14#define CLOCK_TICK_RATE 1024000 /* Underlying HZ */
  15
  16typedef unsigned long cycles_t;
  17
  18static inline cycles_t get_cycles(void)
  19{
  20#ifdef __powerpc64__
  21        return mftb();
  22#else
  23        cycles_t ret;
  24
  25        /*
  26         * For the "cycle" counter we use the timebase lower half.
  27         * Currently only used on SMP.
  28         */
  29
  30        ret = 0;
  31
  32        __asm__ __volatile__(
  33#ifdef CONFIG_PPC_8xx
  34                "97:    mftb %0\n"
  35#else
  36                "97:    mfspr %0, %2\n"
  37#endif
  38                "99:\n"
  39                ".section __ftr_fixup,\"a\"\n"
  40                ".align 2\n"
  41                "98:\n"
  42                "       .long %1\n"
  43                "       .long 0\n"
  44                "       .long 97b-98b\n"
  45                "       .long 99b-98b\n"
  46                "       .long 0\n"
  47                "       .long 0\n"
  48                ".previous"
  49                : "=r" (ret) : "i" (CPU_FTR_601), "i" (SPRN_TBRL));
  50        return ret;
  51#endif
  52}
  53
  54#endif  /* __KERNEL__ */
  55#endif  /* _ASM_POWERPC_TIMEX_H */
  56