freebsd-nq/sys/i386/isa/ipl.s
Steve Passe 20233f27f4 General cleanup of the lock pushdown code. They are grouped and enabled
from machine/smptests.h:

#define PUSHDOWN_LEVEL_1
#define PUSHDOWN_LEVEL_2
#define PUSHDOWN_LEVEL_3
#define PUSHDOWN_LEVEL_4_NOT
1997-09-07 22:04:09 +00:00

371 lines
9.4 KiB
ArmAsm

/*-
* 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
*
* $Id: ipl.s,v 1.21 1997/09/07 21:47:45 smp Exp smp $
*/
/*
* AT/386
* Vector interrupt control section
*/
.data
ALIGN_DATA
/* current priority (all off) */
.globl _cpl
_cpl: .long HWI_MASK | SWI_MASK
.globl _tty_imask
_tty_imask: .long 0
.globl _bio_imask
_bio_imask: .long 0
.globl _net_imask
_net_imask: .long 0
.globl _soft_imask
_soft_imask: .long SWI_MASK
.globl _softnet_imask
_softnet_imask: .long SWI_NET_MASK
.globl _softtty_imask
_softtty_imask: .long SWI_TTY_MASK
/* pending interrupts blocked by splxxx() */
.globl _ipending
_ipending: .long 0
/* set with bits for which queue to service */
.globl _netisr
_netisr: .long 0
.globl _netisrs
_netisrs:
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
.text
/*
* Handle return from interrupts, traps and syscalls.
*/
SUPERALIGN_TEXT
_doreti:
FAKE_MCOUNT(_bintr) /* init "from" _bintr -> _doreti */
addl $4,%esp /* discard unit number */
popl %eax /* cpl or cml to restore */
doreti_next:
/*
* Check for pending HWIs and SWIs atomically with restoring cpl
* and exiting. The check has to be atomic with exiting to stop
* (ipending & ~cpl) changing from zero to nonzero while we're
* looking at it (this wouldn't be fatal but it would increase
* interrupt latency). Restoring cpl has to be atomic with exiting
* so that the stack cannot pile up (the nesting level of interrupt
* handlers is limited by the number of bits in cpl).
*/
#ifdef SMP
cli /* early to prevent INT deadlock */
movl %eax, %edx /* preserve cpl while getting lock */
ICPL_LOCK
movl %edx, %eax
doreti_next2:
#endif
movl %eax,%ecx
#ifdef CPL_AND_CML
orl _cpl, %ecx /* add cpl to cml */
#endif
notl %ecx /* set bit = unmasked level */
#ifndef SMP
cli
#endif
andl _ipending,%ecx /* set bit = unmasked pending INT */
jne doreti_unpend
doreti_exit:
#ifdef CPL_AND_CML
movl %eax, _cml
#else
movl %eax,_cpl
#endif
FAST_ICPL_UNLOCK /* preserves %eax */
MPLOCKED decb _intr_nesting_level
MEXITCOUNT
#ifdef VM86
#ifdef CPL_AND_CML
/* XXX CPL_AND_CML needs work */
#error not ready for vm86
#endif
/*
* XXX
* Sometimes when attempting to return to vm86 mode, cpl is not
* being reset to 0, so here we force it to 0 before returning to
* vm86 mode. doreti_stop is a convenient place to set a breakpoint.
* When the cpl problem is solved, this code can disappear.
*/
ICPL_LOCK
cmpl $0,_cpl
je 1f
testl $PSL_VM,TF_EFLAGS(%esp)
je 1f
doreti_stop:
movl $0,_cpl
nop
1:
FAST_ICPL_UNLOCK /* preserves %eax */
#endif /* VM86 */
#ifdef SMP
#ifdef INTR_SIMPLELOCK
#error code needed here to decide which lock to release, INTR or giant
#endif
/* release the kernel lock */
pushl $_mp_lock /* GIANT_LOCK */
call _MPrellock
add $4, %esp
#endif /* SMP */
.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
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:
movl $0,4+4+32+4(%esp) /* XXX should be the error code */
movl $T_PROTFLT,4+4+32+0(%esp)
jmp alltraps_with_regs_pushed
ALIGN_TEXT
doreti_unpend:
/*
* Enabling interrupts is safe because we haven't restored cpl yet.
* The locking from the "btrl" test is probably no longer necessary.
* We won't miss any new pending interrupts because we will check
* for them again.
*/
#ifdef SMP
/* we enter with cpl locked */
bsfl %ecx, %ecx /* slow, but not worth optimizing */
btrl %ecx, _ipending
jnc doreti_next2 /* some intr cleared memory copy */
cmpl $NHWI, %ecx
jae no_cil
btsl %ecx, _cil
no_cil:
FAST_ICPL_UNLOCK /* preserves %eax */
sti /* late to prevent INT deadlock */
#else
sti
bsfl %ecx,%ecx /* slow, but not worth optimizing */
btrl %ecx,_ipending
jnc doreti_next /* some intr cleared memory copy */
#endif /* SMP */
/*
* Setup JUMP to _Xresume0 thru _Xresume23 for HWIs,
* or
* Setup CALL of swi_tty, swi_net, _softclock, swi_ast for SWIs.
*/
movl ihandlers(,%ecx,4),%edx
testl %edx,%edx
/* XXX SMP this would leave cil set: */
je doreti_next /* "can't happen" */
cmpl $NHWI,%ecx
jae doreti_swi
cli
#ifdef SMP
pushl %eax /* preserve %eax */
ICPL_LOCK
#ifdef CPL_AND_CML
popl _cml
#else
popl _cpl
#endif
FAST_ICPL_UNLOCK
#else
movl %eax,_cpl
#endif
MEXITCOUNT
jmp %edx
ALIGN_TEXT
doreti_swi:
pushl %eax
/*
* The SWI_AST handler has to run at cpl = SWI_AST_MASK and the
* SWI_CLOCK handler at cpl = SWI_CLOCK_MASK, so we have to restore
* all the h/w bits in cpl now and have to worry about stack growth.
* The worst case is currently (30 Jan 1994) 2 SWI handlers nested
* in dying interrupt frames and about 12 HWIs nested in active
* interrupt frames. There are only 4 different SWIs and the HWI
* and SWI masks limit the nesting further.
*/
#ifdef SMP
orl imasks(,%ecx,4), %eax
cli /* prevent INT deadlock */
pushl %eax /* save cpl|cmpl */
ICPL_LOCK
#ifdef CPL_AND_CML
popl _cml /* restore cml */
#else
popl _cpl /* restore cpl */
#endif
FAST_ICPL_UNLOCK
sti
#else
orl imasks(,%ecx,4),%eax
movl %eax,_cpl
#endif
call %edx
popl %eax
jmp doreti_next
ALIGN_TEXT
swi_ast:
addl $8,%esp /* discard raddr & cpl to get trap frame */
testb $SEL_RPL_MASK,TRAPF_CS_OFF(%esp)
je swi_ast_phantom
swi_ast_user:
movl $T_ASTFLT,(2+8+0)*4(%esp)
movb $0,_intr_nesting_level /* finish becoming a trap handler */
call _trap
subl %eax,%eax /* recover cpl|cml */
#ifdef CPL_AND_CML
movl %eax, _cpl
#endif
movb $1,_intr_nesting_level /* for doreti_next to decrement */
jmp doreti_next
ALIGN_TEXT
swi_ast_phantom:
#ifdef VM86
/*
* check for ast from vm86 mode. Placed down here so the jumps do
* not get taken for mainline code.
*/
testl $PSL_VM,TF_EFLAGS(%esp)
jne swi_ast_user
#endif /* VM86 */
/*
* These happen when there is an interrupt in a trap handler before
* ASTs can be masked or in an lcall handler before they can be
* masked or after they are unmasked. They could be avoided for
* trap entries by using interrupt gates, and for lcall exits by
* using by using cli, but they are unavoidable for lcall entries.
*/
cli
ICPL_LOCK
orl $SWI_AST_PENDING, _ipending
/* cpl is unlocked in doreti_exit */
subl %eax,%eax
#ifdef CPL_AND_CML
movl %eax, _cpl
#endif
jmp doreti_exit /* SWI_AST is highest so we must be done */
ALIGN_TEXT
swi_net:
MCOUNT
bsfl _netisr,%eax
je swi_net_done
swi_net_more:
btrl %eax,_netisr
jnc swi_net_next
call *_netisrs(,%eax,4)
swi_net_next:
bsfl _netisr,%eax
jne swi_net_more
swi_net_done:
ret
ALIGN_TEXT
dummynetisr:
MCOUNT
ret
/*
* XXX there should be a registration function to put the handler for the
* attached driver directly in ihandlers. Then this function will go away.
*/
ALIGN_TEXT
swi_tty:
MCOUNT
#include "cy.h"
#if NCY > 0
call _cypoll
#endif
#include "rc.h"
#if NRC > 0
call _rcpoll
#endif
#include "sio.h"
#if NSIO > 0
jmp _siopoll
#else
ret
#endif
#ifdef APIC_IO
#include "i386/isa/apic_ipl.s"
#else
#include "i386/isa/icu_ipl.s"
#endif /* APIC_IO */