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
  16 typedef unsigned long cycles_t;
  17
  18 static 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 */