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

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_VDSO_GETTIMEOFDAY_H
   3 #define __ASM_VDSO_GETTIMEOFDAY_H
   4
   5 #ifndef __ASSEMBLY__
   6
   7 #include <asm/barrier.h>
   8 #include <asm/unistd.h>
   9 #include <asm/csr.h>
  10 #include <uapi/linux/time.h>
  11
  12 #define VDSO_HAS_CLOCK_GETRES   1
  13
  14 static __always_inline
  15 int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
  16                           struct timezone *_tz)
  17 {
  18         register struct __kernel_old_timeval *tv asm("a0") = _tv;
  19         register struct timezone *tz asm("a1") = _tz;
  20         register long ret asm("a0");
  21         register long nr asm("a7") = __NR_gettimeofday;
  22
  23         asm volatile ("ecall\n"
  24                       : "=r" (ret)
  25                       : "r"(tv), "r"(tz), "r"(nr)
  26                       : "memory");
  27
  28         return ret;
  29 }
  30
  31 static __always_inline
  32 long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  33 {
  34         register clockid_t clkid asm("a0") = _clkid;
  35         register struct __kernel_timespec *ts asm("a1") = _ts;
  36         register long ret asm("a0");
  37         register long nr asm("a7") = __NR_clock_gettime;
  38
  39         asm volatile ("ecall\n"
  40                       : "=r" (ret)
  41                       : "r"(clkid), "r"(ts), "r"(nr)
  42                       : "memory");
  43
  44         return ret;
  45 }
  46
  47 static __always_inline
  48 int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  49 {
  50         register clockid_t clkid asm("a0") = _clkid;
  51         register struct __kernel_timespec *ts asm("a1") = _ts;
  52         register long ret asm("a0");
  53         register long nr asm("a7") = __NR_clock_getres;
  54
  55         asm volatile ("ecall\n"
  56                       : "=r" (ret)
  57                       : "r"(clkid), "r"(ts), "r"(nr)
  58                       : "memory");
  59
  60         return ret;
  61 }
  62
  63 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
  64                                                  const struct vdso_data *vd)
  65 {
  66         /*
  67          * The purpose of csr_read(CSR_TIME) is to trap the system into
  68          * M-mode to obtain the value of CSR_TIME. Hence, unlike other
  69          * architecture, no fence instructions surround the csr_read()
  70          */
  71         return csr_read(CSR_TIME);
  72 }
  73
  74 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
  75 {
  76         return _vdso_data;
  77 }
  78
  79 #endif /* !__ASSEMBLY__ */
  80
  81 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */