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
 18static __always_inline int gettimeofday_fallback(
 19				struct __kernel_old_timeval *_tv,
 20				struct timezone *_tz)
 21{
 22	register struct timezone *tz asm("r1") = _tz;
 23	register struct __kernel_old_timeval *tv asm("r0") = _tv;
 24	register long ret asm ("r0");
 25	register long nr asm("r7") = __NR_gettimeofday;
 26
 27	asm volatile(
 28	"	swi #0\n"
 29	: "=r" (ret)
 30	: "r" (tv), "r" (tz), "r" (nr)
 31	: "memory");
 32
 33	return ret;
 34}
 35
 36static __always_inline long clock_gettime_fallback(
 37					clockid_t _clkid,
 38					struct __kernel_timespec *_ts)
 39{
 40	register struct __kernel_timespec *ts asm("r1") = _ts;
 41	register clockid_t clkid asm("r0") = _clkid;
 42	register long ret asm ("r0");
 43	register long nr asm("r7") = __NR_clock_gettime64;
 44
 45	asm volatile(
 46	"	swi #0\n"
 47	: "=r" (ret)
 48	: "r" (clkid), "r" (ts), "r" (nr)
 49	: "memory");
 50
 51	return ret;
 52}
 53
 54static __always_inline long clock_gettime32_fallback(
 55					clockid_t _clkid,
 56					struct old_timespec32 *_ts)
 57{
 58	register struct old_timespec32 *ts asm("r1") = _ts;
 59	register clockid_t clkid asm("r0") = _clkid;
 60	register long ret asm ("r0");
 61	register long nr asm("r7") = __NR_clock_gettime;
 62
 63	asm volatile(
 64	"	swi #0\n"
 65	: "=r" (ret)
 66	: "r" (clkid), "r" (ts), "r" (nr)
 67	: "memory");
 68
 69	return ret;
 70}
 71
 72static __always_inline int clock_getres_fallback(
 73					clockid_t _clkid,
 74					struct __kernel_timespec *_ts)
 75{
 76	register struct __kernel_timespec *ts asm("r1") = _ts;
 77	register clockid_t clkid asm("r0") = _clkid;
 78	register long ret asm ("r0");
 79	register long nr asm("r7") = __NR_clock_getres_time64;
 80
 81	asm volatile(
 82	"       swi #0\n"
 83	: "=r" (ret)
 84	: "r" (clkid), "r" (ts), "r" (nr)
 85	: "memory");
 86
 87	return ret;
 88}
 89
 90static __always_inline int clock_getres32_fallback(
 91					clockid_t _clkid,
 92					struct old_timespec32 *_ts)
 93{
 94	register struct old_timespec32 *ts asm("r1") = _ts;
 95	register clockid_t clkid asm("r0") = _clkid;
 96	register long ret asm ("r0");
 97	register long nr asm("r7") = __NR_clock_getres;
 98
 99	asm volatile(
100	"       swi #0\n"
101	: "=r" (ret)
102	: "r" (clkid), "r" (ts), "r" (nr)
103	: "memory");
104
105	return ret;
106}
107
108static inline bool arm_vdso_hres_capable(void)
109{
110	return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
111}
112#define __arch_vdso_hres_capable arm_vdso_hres_capable
113
114static __always_inline u64 __arch_get_hw_counter(int clock_mode,
115						 const struct vdso_time_data *vd)
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#endif /* !__ASSEMBLY__ */
139
140#endif /* __ASM_VDSO_GETTIMEOFDAY_H */