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