xref: /src/lib/libpthread/arch/i386/pthread_md.h

/*	$NetBSD: pthread_md.h,v 1.16 2009/03/29 09:30:05 ad Exp $	*/

/*-
 * Copyright (c) 2001, 2007, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Nathan J. Williams, and by Andrew Doran.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _LIB_PTHREAD_I386_MD_H
#define _LIB_PTHREAD_I386_MD_H

#include <sys/ucontext.h>
#include <ucontext.h>

extern int (*_md_getcontext_u)(ucontext_t *);
extern int (*_md_setcontext_u)(const ucontext_t *);
extern int (*_md_swapcontext_u)(ucontext_t *, const ucontext_t *);

#define _getcontext_u(uc) (*_md_getcontext_u)((uc))
#define _setcontext_u(uc) (*_md_setcontext_u)((uc))
#define _swapcontext_u(ouc, nuc) (*_md_swapcontext_u)((ouc), (nuc))

int _getcontext_u_s87(ucontext_t *);
int _setcontext_u_s87(const ucontext_t *);
int _swapcontext_u_s87(ucontext_t *, const ucontext_t *);
int _getcontext_u_xmm(ucontext_t *);
int _setcontext_u_xmm(const ucontext_t *);
int _swapcontext_u_xmm(ucontext_t *, const ucontext_t *);

void pthread__i386_init(void);

#define PTHREAD_MD_INIT pthread__i386_init();

static inline long
pthread__sp(void)
{
	long ret;
	__asm("movl %%esp, %0" : "=g" (ret));

	return ret;
}

#define pthread__uc_sp(ucp) ((ucp)->uc_mcontext.__gregs[_REG_UESP])
#define pthread__uc_pc(ucp) ((ucp)->uc_mcontext.__gregs[_REG_EIP])

/*
 * Set initial, sane values for registers whose values aren't just
 * "don't care".
 *
 * We use the current context instead of a guessed one because we cannot
 * assume how the GDT entries are ordered:  what is true on i386 is not
 * true anymore on amd64.
 */
#define _INITCONTEXT_U_MD(ucp)						\
	do {								\
		ucontext_t ucur;					\
		(void)getcontext(&ucur);				\
		(ucp)->uc_mcontext.__gregs[_REG_GS] =			\
		    ucur.uc_mcontext.__gregs[_REG_GS],			\
		(ucp)->uc_mcontext.__gregs[_REG_FS] =			\
		    ucur.uc_mcontext.__gregs[_REG_FS],			\
		(ucp)->uc_mcontext.__gregs[_REG_ES] =			\
		    ucur.uc_mcontext.__gregs[_REG_ES],			\
		(ucp)->uc_mcontext.__gregs[_REG_DS] =			\
		    ucur.uc_mcontext.__gregs[_REG_DS],			\
		(ucp)->uc_mcontext.__gregs[_REG_CS] =			\
		    ucur.uc_mcontext.__gregs[_REG_CS],			\
		(ucp)->uc_mcontext.__gregs[_REG_SS] =			\
		    ucur.uc_mcontext.__gregs[_REG_SS],			\
		(ucp)->uc_mcontext.__gregs[_REG_EFL] =			\
		    ucur.uc_mcontext.__gregs[_REG_EFL];			\
	} while (/*CONSTCOND*/0);

/*
 * Usable stack space below the ucontext_t.
 * See comment in pthread_switch.S about STACK_SWITCH.
 */
#define STACKSPACE	32	/* room for 8 integer values */

/*
 * Conversions between struct reg and struct mcontext. Used by
 * libpthread_dbg.
 */

#define PTHREAD_UCONTEXT_TO_REG(reg, uc) do {				\
	(reg)->r_gs  = (uc)->uc_mcontext.__gregs[_REG_GS];		\
	(reg)->r_fs  = (uc)->uc_mcontext.__gregs[_REG_FS];		\
	(reg)->r_es  = (uc)->uc_mcontext.__gregs[_REG_ES];		\
	(reg)->r_ds  = (uc)->uc_mcontext.__gregs[_REG_DS];		\
	(reg)->r_edi = (uc)->uc_mcontext.__gregs[_REG_EDI];		\
	(reg)->r_esi = (uc)->uc_mcontext.__gregs[_REG_ESI];		\
	(reg)->r_ebp = (uc)->uc_mcontext.__gregs[_REG_EBP];		\
	(reg)->r_ebx = (uc)->uc_mcontext.__gregs[_REG_EBX];		\
	(reg)->r_edx = (uc)->uc_mcontext.__gregs[_REG_EDX];		\
	(reg)->r_ecx = (uc)->uc_mcontext.__gregs[_REG_ECX];		\
	(reg)->r_eax = (uc)->uc_mcontext.__gregs[_REG_EAX];		\
	(reg)->r_eip = (uc)->uc_mcontext.__gregs[_REG_EIP];		\
	(reg)->r_cs  = (uc)->uc_mcontext.__gregs[_REG_CS];		\
	(reg)->r_eflags  = (uc)->uc_mcontext.__gregs[_REG_EFL];		\
	(reg)->r_esp = (uc)->uc_mcontext.__gregs[_REG_UESP];		\
	(reg)->r_ss  = (uc)->uc_mcontext.__gregs[_REG_SS];		\
	} while (/*CONSTCOND*/0)

#define PTHREAD_REG_TO_UCONTEXT(uc, reg) do {				\
	(uc)->uc_mcontext.__gregs[_REG_GS]  = (reg)->r_gs;		\
	(uc)->uc_mcontext.__gregs[_REG_FS]  = (reg)->r_fs; 		\
	(uc)->uc_mcontext.__gregs[_REG_ES]  = (reg)->r_es; 		\
	(uc)->uc_mcontext.__gregs[_REG_DS]  = (reg)->r_ds; 		\
	(uc)->uc_mcontext.__gregs[_REG_EDI] = (reg)->r_edi; 		\
	(uc)->uc_mcontext.__gregs[_REG_ESI] = (reg)->r_esi; 		\
	(uc)->uc_mcontext.__gregs[_REG_EBP] = (reg)->r_ebp; 		\
	(uc)->uc_mcontext.__gregs[_REG_EBX] = (reg)->r_ebx; 		\
	(uc)->uc_mcontext.__gregs[_REG_EDX] = (reg)->r_edx; 		\
	(uc)->uc_mcontext.__gregs[_REG_ECX] = (reg)->r_ecx; 		\
	(uc)->uc_mcontext.__gregs[_REG_EAX] = (reg)->r_eax; 		\
	(uc)->uc_mcontext.__gregs[_REG_EIP] = (reg)->r_eip; 		\
	(uc)->uc_mcontext.__gregs[_REG_CS]  = (reg)->r_cs; 		\
	(uc)->uc_mcontext.__gregs[_REG_EFL] = (reg)->r_eflags; 		\
	(uc)->uc_mcontext.__gregs[_REG_UESP]= (reg)->r_esp;		\
	(uc)->uc_mcontext.__gregs[_REG_SS]  = (reg)->r_ss; 		\
	/*LINTED precision loss */					\
	(uc)->uc_flags = ((uc)->uc_flags | _UC_CPU) & ~_UC_USER; 	\
	} while (/*CONSTCOND*/0)


#define PTHREAD_UCONTEXT_TO_FPREG(freg, uc)		       		\
	(void)memcpy((freg)->__data,					\
        (uc)->uc_mcontext.__fpregs.__fp_reg_set.__fpchip_state.__fp_state, \
	sizeof(struct fpreg))

#define PTHREAD_FPREG_TO_UCONTEXT(uc, freg) do {       	       		\
	(void)memcpy(							\
        (uc)->uc_mcontext.__fpregs.__fp_reg_set.__fpchip_state.__fp_state, \
	(freg)->__data, sizeof(struct fpreg));				\
	/*LINTED precision loss */					\
	(uc)->uc_flags = ((uc)->uc_flags | _UC_FPU) & ~_UC_USER;	\
	} while (/*CONSTCOND*/0)

#define PTHREAD_UCONTEXT_XREG_FLAG	_UC_FXSAVE

#define PTHREAD_UCONTEXT_TO_XREG(xreg, uc)				\
	(void)memcpy((xreg),						\
	(uc)->uc_mcontext.__fpregs.__fp_reg_set.__fp_xmm_state.__fp_xmm, \
	sizeof(struct xmmregs))

#define PTHREAD_XREG_TO_UCONTEXT(uc, xreg) do {				\
	(void)memcpy(							\
	(uc)->uc_mcontext.__fpregs.__fp_reg_set.__fp_xmm_state.__fp_xmm, \
	(xreg),								\
	sizeof(struct xmmregs));					\
	(uc)->uc_flags = ((uc)->uc_flags | _UC_FXSAVE) & ~_UC_USER;	\
	} while (/*CONSTCOND*/0)

#define	pthread__smt_pause()	__asm __volatile("rep; nop" ::: "memory")
/*	#define	PTHREAD__HAVE_THREADREG	*/

/* Don't need additional memory barriers. */
#define	PTHREAD__ATOMIC_IS_MEMBAR

static inline pthread_t
#ifdef __GNUC__
__attribute__ ((__const__))
#endif
pthread__threadreg_get(void)
{
	pthread_t self;

	__asm volatile("movl %%gs:0, %0"
		: "=r" (self)
		:);

	return self;
}

static inline void *
_atomic_cas_ptr(volatile void *ptr, void *old, void *new)
{
	volatile uintptr_t *cast = ptr;
	void *ret;

	__asm __volatile ("lock; cmpxchgl %2, %1"
		: "=a" (ret), "=m" (*cast)
		: "r" (new), "m" (*cast), "0" (old));

	return ret;
}

static inline void *
_atomic_cas_ptr_ni(volatile void *ptr, void *old, void *new)
{
	volatile uintptr_t *cast = ptr;
	void *ret;

	__asm __volatile ("cmpxchgl %2, %1"
		: "=a" (ret), "=m" (*cast)
		: "r" (new), "m" (*cast), "0" (old));

	return ret;
}

#endif /* _LIB_PTHREAD_I386_MD_H */