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 /*
  13  * 32-bit land is lacking generic time vsyscalls as well as the legacy 32-bit
  14  * time syscalls like gettimeofday. Skip these definitions since on 32-bit.
  15  */
  16 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
  17
  18 #define VDSO_HAS_CLOCK_GETRES   1
  19
  20 static __always_inline
  21 int gettimeofday_fallback(struct __kernel_old_timeval *_tv,
  22                           struct timezone *_tz)
  23 {
  24         register struct __kernel_old_timeval *tv asm("a0") = _tv;
  25         register struct timezone *tz asm("a1") = _tz;
  26         register long ret asm("a0");
  27         register long nr asm("a7") = __NR_gettimeofday;
  28
  29         asm volatile ("ecall\n"
  30                       : "=r" (ret)
  31                       : "r"(tv), "r"(tz), "r"(nr)
  32                       : "memory");
  33
  34         return ret;
  35 }
  36
  37 static __always_inline
  38 long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  39 {
  40         register clockid_t clkid asm("a0") = _clkid;
  41         register struct __kernel_timespec *ts asm("a1") = _ts;
  42         register long ret asm("a0");
  43         register long nr asm("a7") = __NR_clock_gettime;
  44
  45         asm volatile ("ecall\n"
  46                       : "=r" (ret)
  47                       : "r"(clkid), "r"(ts), "r"(nr)
  48                       : "memory");
  49
  50         return ret;
  51 }
  52
  53 static __always_inline
  54 int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  55 {
  56         register clockid_t clkid asm("a0") = _clkid;
  57         register struct __kernel_timespec *ts asm("a1") = _ts;
  58         register long ret asm("a0");
  59         register long nr asm("a7") = __NR_clock_getres;
  60
  61         asm volatile ("ecall\n"
  62                       : "=r" (ret)
  63                       : "r"(clkid), "r"(ts), "r"(nr)
  64                       : "memory");
  65
  66         return ret;
  67 }
  68
  69 #endif /* CONFIG_GENERIC_TIME_VSYSCALL */
  70
  71 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
  72                                                  const struct vdso_data *vd)
  73 {
  74         /*
  75          * The purpose of csr_read(CSR_TIME) is to trap the system into
  76          * M-mode to obtain the value of CSR_TIME. Hence, unlike other
  77          * architecture, no fence instructions surround the csr_read()
  78          */
  79         return csr_read(CSR_TIME);
  80 }
  81
  82 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
  83 {
  84         return _vdso_data;
  85 }
  86
  87 #ifdef CONFIG_TIME_NS
  88 static __always_inline
  89 const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
  90 {
  91         return _timens_data;
  92 }
  93 #endif
  94 #endif /* !__ASSEMBLY__ */
  95
  96 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */