freebsd-src/sys/arm64/linux/linux_vdso_gtod.c
Dmitry Chagin e58ff66464 linux(4): Add a write syscall wrapper
Adding a write syscall wrapper is needed due to Linux family of write
syscalls doesn't distinguish between in kernel blocking operations
and always returns EAGAIN while FreeBSD can return ENOBUFS.

MFC after:		1 month
2023-08-20 10:36:29 +03:00

149 lines
4.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
* Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/elf.h>
#include <sys/errno.h>
#include <sys/proc.h>
#include <sys/stddef.h>
#define _KERNEL
#include <sys/vdso.h>
#undef _KERNEL
#include <stdbool.h>
#include <machine/atomic.h>
#include <machine/stdarg.h>
#include <arm64/linux/linux.h>
#include <arm64/linux/linux_syscall.h>
#include <compat/linux/linux_errno.h>
#include <compat/linux/linux_time.h>
/* The kernel fixup this at vDSO install */
uintptr_t *kern_timekeep_base = NULL;
uint32_t kern_tsc_selector = 0;
static int
write(int lfd, const void *lbuf, size_t lsize)
{
register long svc asm("x8") = LINUX_SYS_linux_write;
register int fd asm("x0") = lfd;
register const char *buf asm("x1") = lbuf;
register long size asm("x2") = lsize;
register long res asm ("x0");
asm volatile(
" svc #0\n"
: "=r" (res)
: "r" (fd), "r" (buf), "r" (size), "r" (svc)
: "memory");
return (res);
}
static int
__vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *lts)
{
register long svc asm("x8") = LINUX_SYS_linux_clock_gettime;
register clockid_t clockid asm("x0") = clock_id;
register struct l_timespec *ts asm("x1") = lts;
register long res asm ("x0");
asm volatile(
" svc #0\n"
: "=r" (res)
: "r" (clockid), "r" (ts), "r" (svc)
: "memory");
return (res);
}
static int
__vdso_gettimeofday_fallback(l_timeval *ltv, struct timezone *ltz)
{
register long svc asm("x8") = LINUX_SYS_gettimeofday;
register l_timeval *tv asm("x0") = ltv;
register struct timezone *tz asm("x1") = ltz;
register long res asm ("x0");
asm volatile(
" svc #0\n"
: "=r" (res)
: "r" (tv), "r" (tz), "r" (svc)
: "memory");
return (res);
}
static int
__vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *lts)
{
register long svc asm("x8") = LINUX_SYS_linux_clock_getres;
register clockid_t clockid asm("x0") = clock_id;
register struct l_timespec *ts asm("x1") = lts;
register long res asm ("x0");
asm volatile(
" svc #0\n"
: "=r" (res)
: "r" (clockid), "r" (ts), "r" (svc)
: "memory");
return (res);
}
/*
* copied from lib/libc/aarch64/sys/__vdso_gettc.c
*/
static inline uint64_t
cp15_cntvct_get(void)
{
uint64_t reg;
__asm __volatile("mrs %0, cntvct_el0" : "=r" (reg));
return (reg);
}
static inline uint64_t
cp15_cntpct_get(void)
{
uint64_t reg;
__asm __volatile("mrs %0, cntpct_el0" : "=r" (reg));
return (reg);
}
int
__vdso_gettc(const struct vdso_timehands *th, u_int *tc)
{
if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM)
return (ENOSYS);
__asm __volatile("isb" : : : "memory");
*tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get();
return (0);
}
#include <compat/linux/linux_vdso_gtod.inc>