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freebsd/sys/i386/isa/ipl.s
Peter Wemm dfa67ec76e Store the macro values for SWI_TTY_MASK and SWI_NET_MASK in variables to
that lkm's can use them for fiddling the masks without being dependent on
which mode the kernel is compiled in (SMP or UP).  This is particularly
for ppp_tty.c which has some domain crossing between the net and tty
subsystems.  The values are not used in the spl code, they are for
reference only (ie: the compiled code uses immediate values rather than
an indirect 32 bit address and 32 bit data fetch).
1997-05-31 09:03:52 +00:00

326 lines
8.7 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 1.1 1997/05/26 17:58:27 fsmp Exp $
*/
/*
* AT/386
* Vector interrupt control section
*/
.data
ALIGN_DATA
/* current priority (all off) */
.globl _cpl
_cpl: .long HWI_MASK | SWI_MASK
/* interrupt mask enable (all h/w off) */
.globl _imen
_imen: .long HWI_MASK
.globl _tty_imask
_tty_imask: .long 0
.globl _bio_imask
_bio_imask: .long 0
.globl _net_imask
_net_imask: .long 0
.globl _softnet_imask
_softnet_imask: .long SWI_NET_MASK
.globl _softtty_imask
_softtty_imask: .long SWI_TTY_MASK
.globl _ipending
/* pending interrupts blocked by splxxx() */
_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 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).
*/
movl %eax,%ecx
notl %ecx
cli
andl _ipending,%ecx
jne doreti_unpend
doreti_exit:
movl %eax,_cpl
decb _intr_nesting_level
MEXITCOUNT
REL_MPLOCK
.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.
*/
sti
bsfl %ecx,%ecx /* slow, but not worth optimizing */
MP_INSTR_LOCK
btrl %ecx,_ipending
jnc doreti_next /* some intr cleared memory copy */
movl ihandlers(,%ecx,4),%edx
testl %edx,%edx
je doreti_next /* "can't happen" */
cmpl $NHWI,%ecx
jae doreti_swi
cli
movl %eax,_cpl
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.
*/
orl imasks(,%ecx,4),%eax
movl %eax,_cpl
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
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 */
movb $1,_intr_nesting_level /* for doreti_next to decrement */
jmp doreti_next
ALIGN_TEXT
swi_ast_phantom:
/*
* 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
MP_INSTR_LOCK
orl $SWI_AST_PENDING,_ipending
subl %eax,%eax
jmp doreti_exit /* SWI_AST is highest so we must be done */
/*
* Interrupt priority mechanism
* -- soft splXX masks with group mechanism (cpl)
* -- h/w masks for currently active or unused interrupts (imen)
* -- ipending = active interrupts currently masked by cpl
*/
ENTRY(splz)
/*
* The caller has restored cpl and checked that (ipending & ~cpl)
* is nonzero. We have to repeat the check since if there is an
* interrupt while we're looking, _doreti processing for the
* interrupt will handle all the unmasked pending interrupts
* because we restored early. We're repeating the calculation
* of (ipending & ~cpl) anyway so that the caller doesn't have
* to pass it, so this only costs one "jne". "bsfl %ecx,%ecx"
* is undefined when %ecx is 0 so we can't rely on the secondary
* btrl tests.
*/
movl _cpl,%eax
splz_next:
/*
* We don't need any locking here. (ipending & ~cpl) cannot grow
* while we're looking at it - any interrupt will shrink it to 0.
*/
movl %eax,%ecx
notl %ecx
andl _ipending,%ecx
jne splz_unpend
ret
ALIGN_TEXT
splz_unpend:
bsfl %ecx,%ecx
MP_INSTR_LOCK
btrl %ecx,_ipending
jnc splz_next
movl ihandlers(,%ecx,4),%edx
testl %edx,%edx
je splz_next /* "can't happen" */
cmpl $NHWI,%ecx
jae splz_swi
/*
* We would prefer to call the intr handler directly here but that
* doesn't work for badly behaved handlers that want the interrupt
* frame. Also, there's a problem determining the unit number.
* We should change the interface so that the unit number is not
* determined at config time.
*/
jmp *_vec(,%ecx,4)
ALIGN_TEXT
splz_swi:
cmpl $SWI_AST,%ecx
je splz_next /* "can't happen" */
pushl %eax
orl imasks(,%ecx,4),%eax
movl %eax,_cpl
call %edx
popl %eax
movl %eax,_cpl
jmp splz_next
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 */