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/unistd.h> 12 13 #define VDSO_HAS_CLOCK_GETRES 1 14 15 static __always_inline 16 int gettimeofday_fallback(struct __kernel_old_timeval *_tv, 17 struct timezone *_tz) 18 { 19 register struct timezone *tz asm("x1") = _tz; 20 register struct __kernel_old_timeval *tv asm("x0") = _tv; 21 register long ret asm ("x0"); 22 register long nr asm("x8") = __NR_gettimeofday; 23 24 asm volatile( 25 " svc #0\n" 26 : "=r" (ret) 27 : "r" (tv), "r" (tz), "r" (nr) 28 : "memory"); 29 30 return ret; 31 } 32 33 static __always_inline 34 long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) 35 { 36 register struct __kernel_timespec *ts asm("x1") = _ts; 37 register clockid_t clkid asm("x0") = _clkid; 38 register long ret asm ("x0"); 39 register long nr asm("x8") = __NR_clock_gettime; 40 41 asm volatile( 42 " svc #0\n" 43 : "=r" (ret) 44 : "r" (clkid), "r" (ts), "r" (nr) 45 : "memory"); 46 47 return ret; 48 } 49 50 static __always_inline 51 int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) 52 { 53 register struct __kernel_timespec *ts asm("x1") = _ts; 54 register clockid_t clkid asm("x0") = _clkid; 55 register long ret asm ("x0"); 56 register long nr asm("x8") = __NR_clock_getres; 57 58 asm volatile( 59 " svc #0\n" 60 : "=r" (ret) 61 : "r" (clkid), "r" (ts), "r" (nr) 62 : "memory"); 63 64 return ret; 65 } 66 67 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, 68 const struct vdso_data *vd) 69 { 70 u64 res; 71 72 /* 73 * Core checks for mode already, so this raced against a concurrent 74 * update. Return something. Core will do another round and then 75 * see the mode change and fallback to the syscall. 76 */ 77 if (clock_mode == VDSO_CLOCKMODE_NONE) 78 return 0; 79 80 /* 81 * This isb() is required to prevent that the counter value 82 * is speculated. 83 */ 84 isb(); 85 asm volatile("mrs %0, cntvct_el0" : "=r" (res) :: "memory"); 86 arch_counter_enforce_ordering(res); 87 88 return res; 89 } 90 91 static __always_inline 92 const struct vdso_data *__arch_get_vdso_data(void) 93 { 94 return _vdso_data; 95 } 96 97 #ifdef CONFIG_TIME_NS 98 static __always_inline 99 const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd) 100 { 101 return _timens_data; 102 } 103 #endif 104 105 #endif /* !__ASSEMBLY__ */ 106 107 #endif /* __ASM_VDSO_GETTIMEOFDAY_H */ 108