arch/arm/include/asm/vdso/gettimeofday.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2018 ARM Limited
   4  */
   5 #ifndef __ASM_VDSO_GETTIMEOFDAY_H
   6 #define __ASM_VDSO_GETTIMEOFDAY_H
   7
   8 #ifndef __ASSEMBLY__
   9
  10 #include <asm/errno.h>
  11 #include <asm/unistd.h>
  12 #include <asm/vdso/cp15.h>
  13 #include <uapi/linux/time.h>
  14
  15 #define VDSO_HAS_CLOCK_GETRES           1
  16
  17 extern struct vdso_data *__get_datapage(void);
  18
  19 static __always_inline int gettimeofday_fallback(
  20                                 struct __kernel_old_timeval *_tv,
  21                                 struct timezone *_tz)
  22 {
  23         register struct timezone *tz asm("r1") = _tz;
  24         register struct __kernel_old_timeval *tv asm("r0") = _tv;
  25         register long ret asm ("r0");
  26         register long nr asm("r7") = __NR_gettimeofday;
  27
  28         asm volatile(
  29         "       swi #0\n"
  30         : "=r" (ret)
  31         : "r" (tv), "r" (tz), "r" (nr)
  32         : "memory");
  33
  34         return ret;
  35 }
  36
  37 static __always_inline long clock_gettime_fallback(
  38                                         clockid_t _clkid,
  39                                         struct __kernel_timespec *_ts)
  40 {
  41         register struct __kernel_timespec *ts asm("r1") = _ts;
  42         register clockid_t clkid asm("r0") = _clkid;
  43         register long ret asm ("r0");
  44         register long nr asm("r7") = __NR_clock_gettime64;
  45
  46         asm volatile(
  47         "       swi #0\n"
  48         : "=r" (ret)
  49         : "r" (clkid), "r" (ts), "r" (nr)
  50         : "memory");
  51
  52         return ret;
  53 }
  54
  55 static __always_inline long clock_gettime32_fallback(
  56                                         clockid_t _clkid,
  57                                         struct old_timespec32 *_ts)
  58 {
  59         register struct old_timespec32 *ts asm("r1") = _ts;
  60         register clockid_t clkid asm("r0") = _clkid;
  61         register long ret asm ("r0");
  62         register long nr asm("r7") = __NR_clock_gettime;
  63
  64         asm volatile(
  65         "       swi #0\n"
  66         : "=r" (ret)
  67         : "r" (clkid), "r" (ts), "r" (nr)
  68         : "memory");
  69
  70         return ret;
  71 }
  72
  73 static __always_inline int clock_getres_fallback(
  74                                         clockid_t _clkid,
  75                                         struct __kernel_timespec *_ts)
  76 {
  77         register struct __kernel_timespec *ts asm("r1") = _ts;
  78         register clockid_t clkid asm("r0") = _clkid;
  79         register long ret asm ("r0");
  80         register long nr asm("r7") = __NR_clock_getres_time64;
  81
  82         asm volatile(
  83         "       swi #0\n"
  84         : "=r" (ret)
  85         : "r" (clkid), "r" (ts), "r" (nr)
  86         : "memory");
  87
  88         return ret;
  89 }
  90
  91 static __always_inline int clock_getres32_fallback(
  92                                         clockid_t _clkid,
  93                                         struct old_timespec32 *_ts)
  94 {
  95         register struct old_timespec32 *ts asm("r1") = _ts;
  96         register clockid_t clkid asm("r0") = _clkid;
  97         register long ret asm ("r0");
  98         register long nr asm("r7") = __NR_clock_getres;
  99
 100         asm volatile(
 101         "       swi #0\n"
 102         : "=r" (ret)
 103         : "r" (clkid), "r" (ts), "r" (nr)
 104         : "memory");
 105
 106         return ret;
 107 }
 108
 109 static inline bool arm_vdso_hres_capable(void)
 110 {
 111         return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
 112 }
 113 #define __arch_vdso_hres_capable arm_vdso_hres_capable
 114
 115 static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 116 {
 117 #ifdef CONFIG_ARM_ARCH_TIMER
 118         u64 cycle_now;
 119
 120         /*
 121          * Core checks for mode already, so this raced against a concurrent
 122          * update. Return something. Core will do another round and then
 123          * see the mode change and fallback to the syscall.
 124          */
 125         if (clock_mode == VDSO_CLOCKMODE_NONE)
 126                 return 0;
 127
 128         isb();
 129         cycle_now = read_sysreg(CNTVCT);
 130
 131         return cycle_now;
 132 #else
 133         /* Make GCC happy. This is compiled out anyway */
 134         return 0;
 135 #endif
 136 }
 137
 138 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
 139 {
 140         return __get_datapage();
 141 }
 142
 143 #endif /* !__ASSEMBLY__ */
 144
 145 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */