1/* $OpenBSD: tcb.h,v 1.4 2016/09/04 08:49:35 guenther Exp $ */ 2/* 3 * Copyright (c) 2011 Philip Guenther <guenther@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#ifndef _MACHINE_TCB_H_ 19#define _MACHINE_TCB_H_ 20 21#ifdef _KERNEL 22 23#include <machine/sysarch.h> 24#include <machine/pcb.h> 25 26#define TCB_GET(p) \ 27 ((void *)i386_get_threadbase(p, TSEG_GS)) 28#define TCB_SET(p, addr) \ 29 i386_set_threadbase(p, (uint32_t)(addr), TSEG_GS) 30 31#else /* _KERNEL */ 32 33/* ELF TLS ABI calls for big TCB, with static TLS data at negative offsets */ 34#define TLS_VARIANT 2 35 36/* Read a slot from the TCB */ 37static inline void * 38__i386_read_tcb(int offset) 39{ 40 void *val; 41 __asm__ ("movl %%gs:(%1),%0" : "=r" (val) : "r" (offset)); 42 return val; 43} 44 45/* Get a pointer to the TCB itself */ 46#define TCB_GET() __i386_read_tcb(0) 47 48/* Setting the TCB pointer can only be done via syscall, so no TCB_SET() */ 49 50#endif /* _KERNEL */ 51#endif /* _MACHINE_TCB_H_ */ 52