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/barrier.h>
  11 #include <asm/errno.h>
  12 #include <asm/unistd.h>
  13 #include <asm/vdso/cp15.h>
  14 #include <uapi/linux/time.h>
  15
  16 #define VDSO_HAS_CLOCK_GETRES           1
  17
  18 extern struct vdso_data *__get_datapage(void);
  19
  20 static __always_inline int gettimeofday_fallback(
  21                                 struct __kernel_old_timeval *_tv,
  22                                 struct timezone *_tz)
  23 {
  24         register struct timezone *tz asm("r1") = _tz;
  25         register struct __kernel_old_timeval *tv asm("r0") = _tv;
  26         register long ret asm ("r0");
  27         register long nr asm("r7") = __NR_gettimeofday;
  28
  29         asm volatile(
  30         "       swi #0\n"
  31         : "=r" (ret)
  32         : "r" (tv), "r" (tz), "r" (nr)
  33         : "memory");
  34
  35         return ret;
  36 }
  37
  38 static __always_inline long clock_gettime_fallback(
  39                                         clockid_t _clkid,
  40                                         struct __kernel_timespec *_ts)
  41 {
  42         register struct __kernel_timespec *ts asm("r1") = _ts;
  43         register clockid_t clkid asm("r0") = _clkid;
  44         register long ret asm ("r0");
  45         register long nr asm("r7") = __NR_clock_gettime64;
  46
  47         asm volatile(
  48         "       swi #0\n"
  49         : "=r" (ret)
  50         : "r" (clkid), "r" (ts), "r" (nr)
  51         : "memory");
  52
  53         return ret;
  54 }
  55
  56 static __always_inline long clock_gettime32_fallback(
  57                                         clockid_t _clkid,
  58                                         struct old_timespec32 *_ts)
  59 {
  60         register struct old_timespec32 *ts asm("r1") = _ts;
  61         register clockid_t clkid asm("r0") = _clkid;
  62         register long ret asm ("r0");
  63         register long nr asm("r7") = __NR_clock_gettime;
  64
  65         asm volatile(
  66         "       swi #0\n"
  67         : "=r" (ret)
  68         : "r" (clkid), "r" (ts), "r" (nr)
  69         : "memory");
  70
  71         return ret;
  72 }
  73
  74 static __always_inline int clock_getres_fallback(
  75                                         clockid_t _clkid,
  76                                         struct __kernel_timespec *_ts)
  77 {
  78         register struct __kernel_timespec *ts asm("r1") = _ts;
  79         register clockid_t clkid asm("r0") = _clkid;
  80         register long ret asm ("r0");
  81         register long nr asm("r7") = __NR_clock_getres_time64;
  82
  83         asm volatile(
  84         "       swi #0\n"
  85         : "=r" (ret)
  86         : "r" (clkid), "r" (ts), "r" (nr)
  87         : "memory");
  88
  89         return ret;
  90 }
  91
  92 static __always_inline int clock_getres32_fallback(
  93                                         clockid_t _clkid,
  94                                         struct old_timespec32 *_ts)
  95 {
  96         register struct old_timespec32 *ts asm("r1") = _ts;
  97         register clockid_t clkid asm("r0") = _clkid;
  98         register long ret asm ("r0");
  99         register long nr asm("r7") = __NR_clock_getres;
 100
 101         asm volatile(
 102         "       swi #0\n"
 103         : "=r" (ret)
 104         : "r" (clkid), "r" (ts), "r" (nr)
 105         : "memory");
 106
 107         return ret;
 108 }
 109
 110 static inline bool arm_vdso_hres_capable(void)
 111 {
 112         return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
 113 }
 114 #define __arch_vdso_hres_capable arm_vdso_hres_capable
 115
 116 static __always_inline u64 __arch_get_hw_counter(int clock_mode,
 117                                                  const struct vdso_data *vd)
 118 {
 119 #ifdef CONFIG_ARM_ARCH_TIMER
 120         u64 cycle_now;
 121
 122         /*
 123          * Core checks for mode already, so this raced against a concurrent
 124          * update. Return something. Core will do another round and then
 125          * see the mode change and fallback to the syscall.
 126          */
 127         if (clock_mode == VDSO_CLOCKMODE_NONE)
 128                 return 0;
 129
 130         isb();
 131         cycle_now = read_sysreg(CNTVCT);
 132
 133         return cycle_now;
 134 #else
 135         /* Make GCC happy. This is compiled out anyway */
 136         return 0;
 137 #endif
 138 }
 139
 140 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
 141 {
 142         return __get_datapage();
 143 }
 144
 145 #endif /* !__ASSEMBLY__ */
 146
 147 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */