1 /* $OpenBSD: tcb.h,v 1.2 2011/12/24 04:21:19 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 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 #include <stddef.h> /* for offsetof */ 34 35 /* ELF TLS ABI calls for big TCB, with static TLS data at negative offsets */ 36 #define TLS_VARIANT 2 37 38 /* Read a slot from the TCB */ 39 static inline void * 40 __i386_read_tcb(int offset) 41 { 42 void *val; 43 __asm__ ("movl %%gs:(%1),%0" : "=r" (val) : "r" (offset)); 44 return val; 45 } 46 47 /* Get a pointer to the TCB itself */ 48 #define TCB_GET() __i386_read_tcb(0) 49 50 /* Get the value of a specific member in the TCB */ 51 #define TCB_GET_MEMBER(member) \ 52 __i386_read_tcb(offsetof(struct thread_control_block, member)) 53 54 /* Setting the TCB pointer can only be done via syscall, so no TCB_SET() */ 55 56 #endif /* _KERNEL */ 57 58 #endif /* _MACHINE_TCB_H_ */ 59