diff options
Diffstat (limited to 'arch/arm64/include/asm/vdso/compat_gettimeofday.h')
| -rw-r--r-- | arch/arm64/include/asm/vdso/compat_gettimeofday.h | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h new file mode 100644 index 000000000000..0d513f924321 --- /dev/null +++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h @@ -0,0 +1,166 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 ARM Limited + */ +#ifndef __ASM_VDSO_COMPAT_GETTIMEOFDAY_H +#define __ASM_VDSO_COMPAT_GETTIMEOFDAY_H + +#ifndef __ASSEMBLER__ + +#include <asm/barrier.h> +#include <asm/unistd_compat_32.h> +#include <asm/errno.h> + +#include <asm/vdso/compat_barrier.h> + +#define VDSO_HAS_CLOCK_GETRES 1 + +#define BUILD_VDSO32 1 + +static __always_inline +int gettimeofday_fallback(struct __kernel_old_timeval *_tv, + struct timezone *_tz) +{ + register struct timezone *tz asm("r1") = _tz; + register struct __kernel_old_timeval *tv asm("r0") = _tv; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat32_gettimeofday; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (tv), "r" (tz), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline +long clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat32_clock_gettime64; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline +long clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) +{ + register struct old_timespec32 *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat32_clock_gettime; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline +int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) +{ + register struct __kernel_timespec *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat32_clock_getres_time64; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline +int clock_getres32_fallback(clockid_t _clkid, struct old_timespec32 *_ts) +{ + register struct old_timespec32 *ts asm("r1") = _ts; + register clockid_t clkid asm("r0") = _clkid; + register long ret asm ("r0"); + register long nr asm("r7") = __NR_compat32_clock_getres; + + asm volatile( + " swi #0\n" + : "=r" (ret) + : "r" (clkid), "r" (ts), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, + const struct vdso_time_data *vd) +{ + u64 res; + + /* + * Core checks for mode already, so this raced against a concurrent + * update. Return something. Core will do another round and then + * see the mode change and fallback to the syscall. + */ + if (clock_mode != VDSO_CLOCKMODE_ARCHTIMER) + return 0; + + /* + * This isb() is required to prevent that the counter value + * is speculated. + */ + isb(); + asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (res)); + /* + * This isb() is required to prevent that the seq lock is + * speculated. + */ + isb(); + + return res; +} + +static __always_inline const struct vdso_time_data *__arch_get_vdso_u_time_data(void) +{ + const struct vdso_time_data *ret; + + /* + * This simply puts &_vdso_time_data into ret. The reason why we don't use + * `ret = _vdso_time_data` is that the compiler tends to optimise this in a + * very suboptimal way: instead of keeping &_vdso_time_data in a register, + * it goes through a relocation almost every time _vdso_time_data must be + * accessed (even in subfunctions). This is both time and space + * consuming: each relocation uses a word in the code section, and it + * has to be loaded at runtime. + * + * This trick hides the assignment from the compiler. Since it cannot + * track where the pointer comes from, it will only use one relocation + * where __aarch64_get_vdso_u_time_data() is called, and then keep the + * result in a register. + */ + asm volatile("mov %0, %1" : "=r"(ret) : "r"(&vdso_u_time_data)); + + return ret; +} +#define __arch_get_vdso_u_time_data __arch_get_vdso_u_time_data + +static inline bool vdso_clocksource_ok(const struct vdso_clock *vc) +{ + return vc->clock_mode == VDSO_CLOCKMODE_ARCHTIMER; +} +#define vdso_clocksource_ok vdso_clocksource_ok + +#endif /* !__ASSEMBLER__ */ + +#endif /* __ASM_VDSO_COMPAT_GETTIMEOFDAY_H */ |