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 30 #include <sys/cdefs.h> 31 #include <sys/elf.h> 32 #include <sys/errno.h> 33 #include <sys/proc.h> 34 #include <sys/stddef.h> 35 #define _KERNEL 36 #include <sys/vdso.h> 37 #undef _KERNEL 38 #include <stdbool.h> 39 40 #include <machine/atomic.h> 41 #include <machine/stdarg.h> 42 43 #include <arm64/linux/linux.h> 44 #include <arm64/linux/linux_syscall.h> 45 #include <compat/linux/linux_errno.h> 46 #include <compat/linux/linux_time.h> 47 48 /* The kernel fixup this at vDSO install */ 49 uintptr_t *kern_timekeep_base = NULL; 50 uint32_t kern_tsc_selector = 0; 51 52 static int 53 write(int lfd, const void *lbuf, size_t lsize) 54 { 55 register long svc asm("x8") = LINUX_SYS_write; 56 register int fd asm("x0") = lfd; 57 register const char *buf asm("x1") = lbuf; 58 register long size asm("x2") = lsize; 59 register long res asm ("x0"); 60 61 asm volatile( 62 " svc #0\n" 63 : "=r" (res) 64 : "r" (fd), "r" (buf), "r" (size), "r" (svc) 65 : "memory"); 66 return (res); 67 } 68 69 static int 70 __vdso_clock_gettime_fallback(clockid_t clock_id, struct l_timespec *lts) 71 { 72 register long svc asm("x8") = LINUX_SYS_linux_clock_gettime; 73 register clockid_t clockid asm("x0") = clock_id; 74 register struct l_timespec *ts asm("x1") = lts; 75 register long res asm ("x0"); 76 77 asm volatile( 78 " svc #0\n" 79 : "=r" (res) 80 : "r" (clockid), "r" (ts), "r" (svc) 81 : "memory"); 82 return (res); 83 } 84 85 static int 86 __vdso_gettimeofday_fallback(l_timeval *ltv, struct timezone *ltz) 87 { 88 register long svc asm("x8") = LINUX_SYS_gettimeofday; 89 register l_timeval *tv asm("x0") = ltv; 90 register struct timezone *tz asm("x1") = ltz; 91 register long res asm ("x0"); 92 93 asm volatile( 94 " svc #0\n" 95 : "=r" (res) 96 : "r" (tv), "r" (tz), "r" (svc) 97 : "memory"); 98 return (res); 99 } 100 101 static int 102 __vdso_clock_getres_fallback(clockid_t clock_id, struct l_timespec *lts) 103 { 104 register long svc asm("x8") = LINUX_SYS_linux_clock_getres; 105 register clockid_t clockid asm("x0") = clock_id; 106 register struct l_timespec *ts asm("x1") = lts; 107 register long res asm ("x0"); 108 109 asm volatile( 110 " svc #0\n" 111 : "=r" (res) 112 : "r" (clockid), "r" (ts), "r" (svc) 113 : "memory"); 114 return (res); 115 } 116 117 /* 118 * copied from lib/libc/aarch64/sys/__vdso_gettc.c 119 */ 120 121 static inline uint64_t 122 cp15_cntvct_get(void) 123 { 124 uint64_t reg; 125 126 __asm __volatile("mrs %0, cntvct_el0" : "=r" (reg)); 127 return (reg); 128 } 129 130 static inline uint64_t 131 cp15_cntpct_get(void) 132 { 133 uint64_t reg; 134 135 __asm __volatile("mrs %0, cntpct_el0" : "=r" (reg)); 136 return (reg); 137 } 138 139 int 140 __vdso_gettc(const struct vdso_timehands *th, u_int *tc) 141 { 142 143 if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM) 144 return (ENOSYS); 145 __asm __volatile("isb" : : : "memory"); 146 *tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get(); 147 return (0); 148 } 149 150 #include <compat/linux/linux_vdso_gtod.inc> 151