1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org> 5 * Copyright (c) 2021 Dmitry Chagin <dchagin@FreeBSD.org> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/elf.h> 30 #include <sys/errno.h> 31 #include <sys/proc.h> 32 #include <sys/stddef.h> 33 #define _KERNEL 34 #include <sys/vdso.h> 35 #undef _KERNEL 36 #include <stdbool.h> 37 38 #include <machine/atomic.h> 39 #include <machine/stdarg.h> 40 41 #include <arm64/linux/linux.h> 42 #include <arm64/linux/linux_syscall.h> 43 #include <compat/linux/linux_errno.h> 44 #include <compat/linux/linux_time.h> 45 46 /* The kernel fixup this at vDSO install */ 47 uintptr_t *kern_timekeep_base = NULL; 48 uint32_t kern_tsc_selector = 0; 49 50 static int 51 write(int lfd, const void *lbuf, size_t lsize) 52 { 53 register long svc asm("x8") = LINUX_SYS_linux_write; 54 register int fd asm("x0") = lfd; 55 register const char *buf asm("x1") = lbuf; 56 register long size asm("x2") = lsize; 57 register long res asm ("x0"); 58 59 asm volatile( 60 " svc #0\n" 61 : "=r" (res) 62 : "r" (fd), "r" (buf), "r" (size), "r" (svc) 63 : "memory"); 64 return (res); 65 } 66 67 static int 68 __vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *lts) 69 { 70 register long svc asm("x8") = LINUX_SYS_linux_clock_gettime; 71 register clockid_t clockid asm("x0") = clock_id; 72 register struct l_timespec *ts asm("x1") = lts; 73 register long res asm ("x0"); 74 75 asm volatile( 76 " svc #0\n" 77 : "=r" (res) 78 : "r" (clockid), "r" (ts), "r" (svc) 79 : "memory"); 80 return (res); 81 } 82 83 static int 84 __vdso_gettimeofday_fallback(l_timeval *ltv, struct timezone *ltz) 85 { 86 register long svc asm("x8") = LINUX_SYS_gettimeofday; 87 register l_timeval *tv asm("x0") = ltv; 88 register struct timezone *tz asm("x1") = ltz; 89 register long res asm ("x0"); 90 91 asm volatile( 92 " svc #0\n" 93 : "=r" (res) 94 : "r" (tv), "r" (tz), "r" (svc) 95 : "memory"); 96 return (res); 97 } 98 99 static int 100 __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *lts) 101 { 102 register long svc asm("x8") = LINUX_SYS_linux_clock_getres; 103 register clockid_t clockid asm("x0") = clock_id; 104 register struct l_timespec *ts asm("x1") = lts; 105 register long res asm ("x0"); 106 107 asm volatile( 108 " svc #0\n" 109 : "=r" (res) 110 : "r" (clockid), "r" (ts), "r" (svc) 111 : "memory"); 112 return (res); 113 } 114 115 /* 116 * copied from lib/libc/aarch64/sys/__vdso_gettc.c 117 */ 118 119 static inline uint64_t 120 cp15_cntvct_get(void) 121 { 122 uint64_t reg; 123 124 __asm __volatile("mrs %0, cntvct_el0" : "=r" (reg)); 125 return (reg); 126 } 127 128 static inline uint64_t 129 cp15_cntpct_get(void) 130 { 131 uint64_t reg; 132 133 __asm __volatile("mrs %0, cntpct_el0" : "=r" (reg)); 134 return (reg); 135 } 136 137 int 138 __vdso_gettc(const struct vdso_timehands *th, u_int *tc) 139 { 140 141 if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM) 142 return (ENOSYS); 143 __asm __volatile("isb" : : : "memory"); 144 *tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get(); 145 return (0); 146 } 147 148 #include <compat/linux/linux_vdso_gtod.inc> 149