arch/powerpc/include/asm/vdso/timebase.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Common timebase prototypes and such for all ppc machines.
   4  */
   5
   6 #ifndef _ASM_POWERPC_VDSO_TIMEBASE_H
   7 #define _ASM_POWERPC_VDSO_TIMEBASE_H
   8
   9 #include <asm/reg.h>
  10
  11 /*
  12  * We use __powerpc64__ here because we want the compat VDSO to use the 32-bit
  13  * version below in the else case of the ifdef.
  14  */
  15 #if defined(__powerpc64__) && (defined(CONFIG_PPC_CELL) || defined(CONFIG_E500))
  16 #define mftb()          ({unsigned long rval;                           \
  17                         asm volatile(                                   \
  18                                 "90:    mfspr %0, %2;\n"                \
  19                                 ASM_FTR_IFSET(                          \
  20                                         "97:    cmpwi %0,0;\n"          \
  21                                         "       beq- 90b;\n", "", %1)   \
  22                         : "=r" (rval) \
  23                         : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL) : "cr0"); \
  24                         rval;})
  25 #elif defined(CONFIG_PPC_8xx)
  26 #define mftb()          ({unsigned long rval;   \
  27                         asm volatile("mftbl %0" : "=r" (rval)); rval;})
  28 #else
  29 #define mftb()          ({unsigned long rval;   \
  30                         asm volatile("mfspr %0, %1" : \
  31                                      "=r" (rval) : "i" (SPRN_TBRL)); rval;})
  32 #endif /* !CONFIG_PPC_CELL */
  33
  34 #if defined(CONFIG_PPC_8xx)
  35 #define mftbu()         ({unsigned long rval;   \
  36                         asm volatile("mftbu %0" : "=r" (rval)); rval;})
  37 #else
  38 #define mftbu()         ({unsigned long rval;   \
  39                         asm volatile("mfspr %0, %1" : "=r" (rval) : \
  40                                 "i" (SPRN_TBRU)); rval;})
  41 #endif
  42
  43 #define mttbl(v)        asm volatile("mttbl %0":: "r"(v))
  44 #define mttbu(v)        asm volatile("mttbu %0":: "r"(v))
  45
  46 /* For compatibility, get_tbl() is defined as get_tb() on ppc64 */
  47 static inline unsigned long get_tbl(void)
  48 {
  49         return mftb();
  50 }
  51
  52 static __always_inline u64 get_tb(void)
  53 {
  54         unsigned int tbhi, tblo, tbhi2;
  55
  56         /*
  57          * We use __powerpc64__ here not CONFIG_PPC64 because we want the compat
  58          * VDSO to use the 32-bit compatible version in the while loop below.
  59          */
  60         if (__is_defined(__powerpc64__))
  61                 return mftb();
  62
  63         do {
  64                 tbhi = mftbu();
  65                 tblo = mftb();
  66                 tbhi2 = mftbu();
  67         } while (tbhi != tbhi2);
  68
  69         return ((u64)tbhi << 32) | tblo;
  70 }
  71
  72 static inline void set_tb(unsigned int upper, unsigned int lower)
  73 {
  74         mtspr(SPRN_TBWL, 0);
  75         mtspr(SPRN_TBWU, upper);
  76         mtspr(SPRN_TBWL, lower);
  77 }
  78
  79 #endif /* _ASM_POWERPC_VDSO_TIMEBASE_H */