1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2015 The FreeBSD Foundation 5 * 6 * This software was developed by Konstantin Belousov 7 * under sponsorship from the FreeBSD Foundation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 #include <sys/elf.h> 33 #include <sys/time.h> 34 #include <sys/vdso.h> 35 #include <machine/cpufunc.h> 36 #include <machine/acle-compat.h> 37 #include <errno.h> 38 #include "libc_private.h" 39 40 static inline uint64_t 41 cp15_cntvct_get(void) 42 { 43 uint64_t reg; 44 45 __asm __volatile("mrrc\tp15, 1, %Q0, %R0, c14" : "=r" (reg)); 46 return (reg); 47 } 48 49 static inline uint64_t 50 cp15_cntpct_get(void) 51 { 52 uint64_t reg; 53 54 __asm __volatile("mrrc\tp15, 0, %Q0, %R0, c14" : "=r" (reg)); 55 return (reg); 56 } 57 58 #pragma weak __vdso_gettc 59 int 60 __vdso_gettc(const struct vdso_timehands *th, u_int *tc) 61 { 62 63 if (th->th_algo != VDSO_TH_ALGO_ARM_GENTIM) 64 return (ENOSYS); 65 /* 66 * Userspace gettimeofday() is only enabled on ARMv7 CPUs, but 67 * libc is compiled for ARMv6. Due to clang issues, .arch 68 * armv7-a directive does not work. 69 */ 70 __asm __volatile(".word\t0xf57ff06f" : : : "memory"); /* isb */ 71 *tc = th->th_physical == 0 ? cp15_cntvct_get() : cp15_cntpct_get(); 72 return (0); 73 } 74 75 #pragma weak __vdso_gettimekeep 76 int 77 __vdso_gettimekeep(struct vdso_timekeep **tk) 78 { 79 80 return (_elf_aux_info(AT_TIMEKEEP, tk, sizeof(*tk))); 81 } 82