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/*-
 * Copyright (c) 1989, 1990 William F. Jolitz.
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)ipl.s
 *
 * $FreeBSD$
 */


/*
 * AT/386
 * Vector interrupt control section
 */

	.text

/*
 * void doreti(struct trapframe)
 *
 * Handle return from interrupts, traps and syscalls.
 */
	SUPERALIGN_TEXT
	.type	_doreti,@function
_doreti:
	FAKE_MCOUNT(_bintr)		/* init "from" _bintr -> _doreti */
doreti_next:
	decb	PCPU(INTR_NESTING_LEVEL)

	/* Check for ASTs that can be handled now. */
	testl	$AST_PENDING,PCPU(ASTPENDING)
	je	doreti_exit		/* no AST, exit */
	testb	$SEL_RPL_MASK,TF_CS(%esp)  /* are we in user mode? */
	jne	doreti_ast		/* yes, do it now. */
	testl	$PSL_VM,TF_EFLAGS(%esp) /* kernel mode */
	je	doreti_exit		/* and not VM86 mode, defer */
	cmpl	$1,_in_vm86call		/* are we in a VM86 call? */
	jne	doreti_ast		/* yes, we can do it */

	/*
	 * doreti_exit:	release MP lock, pop registers, iret.
	 *
	 *	Note that the syscall trap shortcuts to doreti_syscall_ret.
	 *	The segment register pop is a special case, since it may
	 *	fault if (for example) a sigreturn specifies bad segment
	 *	registers.  The fault is handled in trap.c.
	 */
doreti_exit:
	MEXITCOUNT

	.globl	doreti_popl_fs
	.globl	doreti_syscall_ret
doreti_syscall_ret:
doreti_popl_fs:
	popl	%fs
	.globl	doreti_popl_es
doreti_popl_es:
	popl	%es
	.globl	doreti_popl_ds
doreti_popl_ds:
	popl	%ds
	popal
	addl	$8,%esp
	.globl	doreti_iret
doreti_iret:
	iret

  	/*
	 * doreti_iret_fault and friends.  Alternative return code for
	 * the case where we get a fault in the doreti_exit code
	 * above.  trap() (i386/i386/trap.c) catches this specific
	 * case, sends the process a signal and continues in the
	 * corresponding place in the code below.
	 */
	ALIGN_TEXT
	.globl	doreti_iret_fault
doreti_iret_fault:
	subl	$8,%esp
	pushal
	pushl	%ds
	.globl	doreti_popl_ds_fault
doreti_popl_ds_fault:
	pushl	%es
	.globl	doreti_popl_es_fault
doreti_popl_es_fault:
	pushl	%fs
	.globl	doreti_popl_fs_fault
doreti_popl_fs_fault:
	movl	$0,TF_ERR(%esp)	/* XXX should be the error code */
	movl	$T_PROTFLT,TF_TRAPNO(%esp)
	jmp	alltraps_with_regs_pushed

	ALIGN_TEXT
doreti_ast:
	andl	$~AST_PENDING,PCPU(ASTPENDING)
	sti
	movl	$T_ASTFLT,TF_TRAPNO(%esp)
	call	_ast
	movb	$1,PCPU(INTR_NESTING_LEVEL) /* for doreti_next to decrement */
	jmp	doreti_next

#ifdef APIC_IO
#include "i386/isa/apic_ipl.s"
#else
#include "i386/isa/icu_ipl.s"
#endif /* APIC_IO */
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