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/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* 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.
*
* $FreeBSD$
*/
#include "opt_npx.h"
#include <machine/asmacros.h>
#include <sys/ipl.h>
#include <sys/mutex.h>
#include <machine/lock.h>
#include <machine/psl.h>
#include <machine/trap.h>
#ifdef SMP
#include <machine/smptests.h> /** various SMP options */
#endif
#include "assym.s"
#define SEL_RPL_MASK 0x0003
.text
/*****************************************************************************/
/* Trap handling */
/*****************************************************************************/
/*
* Trap and fault vector routines.
*
* Most traps are 'trap gates', SDT_SYS386TGT. A trap gate pushes state on
* the stack that mostly looks like an interrupt, but does not disable
* interrupts. A few of the traps we are use are interrupt gates,
* SDT_SYS386IGT, which are nearly the same thing except interrupts are
* disabled on entry.
*
* The cpu will push a certain amount of state onto the kernel stack for
* the current process. The amount of state depends on the type of trap
* and whether the trap crossed rings or not. See i386/include/frame.h.
* At the very least the current EFLAGS (status register, which includes
* the interrupt disable state prior to the trap), the code segment register,
* and the return instruction pointer are pushed by the cpu. The cpu
* will also push an 'error' code for certain traps. We push a dummy
* error code for those traps where the cpu doesn't in order to maintain
* a consistent frame. We also push a contrived 'trap number'.
*
* The cpu does not push the general registers, we must do that, and we
* must restore them prior to calling 'iret'. The cpu adjusts the %cs and
* %ss segment registers, but does not mess with %ds, %es, or %fs. Thus we
* must load them with appropriate values for supervisor mode operation.
*
* On entry to a trap or interrupt WE DO NOT OWN THE MP LOCK. This means
* that we must be careful in regards to accessing global variables. We
* save (push) the current cpl (our software interrupt disable mask), call
* the trap function, then call _doreti to restore the cpl and deal with
* ASTs (software interrupts). _doreti will determine if the restoration
* of the cpl unmasked any pending interrupts and will issue those interrupts
* synchronously prior to doing the iret.
*
* At the moment we must own the MP lock to do any cpl manipulation, which
* means we must own it prior to calling _doreti. The syscall case attempts
* to avoid this by handling a reduced set of cases itself and iret'ing.
*/
#define IDTVEC(name) ALIGN_TEXT; .globl __CONCAT(_X,name); \
.type __CONCAT(_X,name),@function; __CONCAT(_X,name):
#define TRAP(a) pushl $(a) ; jmp _alltraps
#ifdef BDE_DEBUGGER
#define BDBTRAP(name) \
ss ; \
cmpb $0,_bdb_exists ; \
je 1f ; \
testb $SEL_RPL_MASK,4(%esp) ; \
jne 1f ; \
ss ; \
.globl __CONCAT(__CONCAT(bdb_,name),_ljmp); \
__CONCAT(__CONCAT(bdb_,name),_ljmp): \
ljmp $0,$0 ; \
1:
#else
#define BDBTRAP(name)
#endif
#define BPTTRAP(a) testl $PSL_I,4+8(%esp) ; je 1f ; sti ; 1: ; TRAP(a)
MCOUNT_LABEL(user)
MCOUNT_LABEL(btrap)
IDTVEC(div)
pushl $0; TRAP(T_DIVIDE)
IDTVEC(dbg)
BDBTRAP(dbg)
pushl $0; BPTTRAP(T_TRCTRAP)
IDTVEC(nmi)
pushl $0; TRAP(T_NMI)
IDTVEC(bpt)
BDBTRAP(bpt)
pushl $0; BPTTRAP(T_BPTFLT)
IDTVEC(ofl)
pushl $0; TRAP(T_OFLOW)
IDTVEC(bnd)
pushl $0; TRAP(T_BOUND)
IDTVEC(ill)
pushl $0; TRAP(T_PRIVINFLT)
IDTVEC(dna)
pushl $0; TRAP(T_DNA)
IDTVEC(fpusegm)
pushl $0; TRAP(T_FPOPFLT)
IDTVEC(tss)
TRAP(T_TSSFLT)
IDTVEC(missing)
TRAP(T_SEGNPFLT)
IDTVEC(stk)
TRAP(T_STKFLT)
IDTVEC(prot)
TRAP(T_PROTFLT)
IDTVEC(page)
TRAP(T_PAGEFLT)
IDTVEC(mchk)
pushl $0; TRAP(T_MCHK)
IDTVEC(rsvd)
pushl $0; TRAP(T_RESERVED)
IDTVEC(fpu)
#ifdef DEV_NPX
/*
* Handle like an interrupt (except for accounting) so that we can
* call npx_intr to clear the error. It would be better to handle
* npx interrupts as traps. Nested interrupts would probably have
* to be converted to ASTs.
*/
pushl $0 /* dummy error code */
pushl $0 /* dummy trap type */
pushal
pushl %ds
pushl %es /* now stack frame is a trap frame */
pushl %fs
mov $KDSEL,%ax
mov %ax,%ds
mov %ax,%es
mov $KPSEL,%ax
mov %ax,%fs
FAKE_MCOUNT(13*4(%esp))
MPLOCKED incl _cnt+V_TRAP
pushl $0 /* dummy unit to finish intr frame */
call _npx_intr
addl $4,%esp
MEXITCOUNT
jmp _doreti
#else /* DEV_NPX */
pushl $0; TRAP(T_ARITHTRAP)
#endif /* DEV_NPX */
IDTVEC(align)
TRAP(T_ALIGNFLT)
/*
* _alltraps entry point. Interrupts are enabled if this was a trap
* gate (TGT), else disabled if this was an interrupt gate (IGT).
* Note that int0x80_syscall is a trap gate. Only page faults
* use an interrupt gate.
*/
SUPERALIGN_TEXT
.globl _alltraps
.type _alltraps,@function
_alltraps:
pushal
pushl %ds
pushl %es
pushl %fs
alltraps_with_regs_pushed:
mov $KDSEL,%ax
mov %ax,%ds
mov %ax,%es
mov $KPSEL,%ax
mov %ax,%fs
FAKE_MCOUNT(13*4(%esp))
calltrap:
FAKE_MCOUNT(_btrap) /* init "from" _btrap -> calltrap */
call _trap
/*
* Return via _doreti to handle ASTs.
*/
MEXITCOUNT
jmp _doreti
/*
* SYSCALL CALL GATE (old entry point for a.out binaries)
*
* The intersegment call has been set up to specify one dummy parameter.
*
* This leaves a place to put eflags so that the call frame can be
* converted to a trap frame. Note that the eflags is (semi-)bogusly
* pushed into (what will be) tf_err and then copied later into the
* final spot. It has to be done this way because esp can't be just
* temporarily altered for the pushfl - an interrupt might come in
* and clobber the saved cs/eip.
*
* We do not obtain the MP lock, but the call to syscall might. If it
* does it will release the lock prior to returning.
*/
SUPERALIGN_TEXT
IDTVEC(syscall)
pushfl /* save eflags in tf_err for now */
subl $4,%esp /* skip over tf_trapno */
pushal
pushl %ds
pushl %es
pushl %fs
mov $KDSEL,%ax /* switch to kernel segments */
mov %ax,%ds
mov %ax,%es
mov $KPSEL,%ax
mov %ax,%fs
movl TF_ERR(%esp),%eax /* copy saved eflags to final spot */
movl %eax,TF_EFLAGS(%esp)
movl $7,TF_ERR(%esp) /* sizeof "lcall 7,0" */
FAKE_MCOUNT(13*4(%esp))
call _syscall
MEXITCOUNT
jmp _doreti
/*
* Call gate entry for FreeBSD ELF and Linux/NetBSD syscall (int 0x80)
*
* Even though the name says 'int0x80', this is actually a TGT (trap gate)
* rather then an IGT (interrupt gate). Thus interrupts are enabled on
* entry just as they are for a normal syscall.
*
* We do not obtain the MP lock, but the call to syscall might. If it
* does it will release the lock prior to returning.
*/
SUPERALIGN_TEXT
IDTVEC(int0x80_syscall)
subl $8,%esp /* skip over tf_trapno and tf_err */
pushal
pushl %ds
pushl %es
pushl %fs
mov $KDSEL,%ax /* switch to kernel segments */
mov %ax,%ds
mov %ax,%es
mov $KPSEL,%ax
mov %ax,%fs
movl $2,TF_ERR(%esp) /* sizeof "int 0x80" */
FAKE_MCOUNT(13*4(%esp))
call _syscall
MEXITCOUNT
jmp _doreti
ENTRY(fork_trampoline)
pushl %esp /* trapframe pointer */
pushl %ebx /* arg1 */
pushl %esi /* function */
call _fork_exit
addl $12,%esp
/* cut from syscall */
/*
* Return via _doreti to handle ASTs.
*/
MEXITCOUNT
jmp _doreti
/*
* Include vm86 call routines, which want to call _doreti.
*/
#include "i386/i386/vm86bios.s"
/*
* Include what was once config+isa-dependent code.
* XXX it should be in a stand-alone file. It's still icu-dependent and
* belongs in i386/isa.
*/
#include "i386/isa/vector.s"
/*
* Include what was once icu-dependent code.
* XXX it should be merged into this file (also move the definition of
* imen to vector.s or isa.c).
* Before including it, set up a normal asm environment so that vector.s
* doesn't have to know that stuff is included after it.
*/
.data
ALIGN_DATA
.text
SUPERALIGN_TEXT
#include "i386/isa/ipl.s"
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