freebsd-skq/sys/i386/isa/icu_ipl.s
Steve Passe 886e789627 The last of the encapsolation of cpl/spl/ipending things into a critical
region protected by the simplelock 'cpl_lock'.

Notes:

 - this code is currently controlled on a section by section basis with
   defines in machine/param.h.  All sections are currently enabled.

 - this code is not as clean as I would like, but that can wait till later.

 - the "giant lock" still surrounds most instances of this "cpl region".
   I still have to do the code that arbitrates setting cpl between the
   top and bottom halves of the kernel.

 - the possibility of deadlock exists, I am committing the code at this
   point so as to exercise it and detect any such cases B4 the "giant lock"
   is removed.
1997-08-24 00:05:37 +00:00

176 lines
4.9 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.
*
* $Id: icu_ipl.s,v 1.2 1997/08/22 05:05:05 smp Exp smp $
*/
.data
ALIGN_DATA
.globl _vec
_vec:
.long vec0, vec1, vec2, vec3, vec4, vec5, vec6, vec7
.long vec8, vec9, vec10, vec11, vec12, vec13, vec14, vec15
/* interrupt mask enable (all h/w off) */
.globl _imen
_imen: .long HWI_MASK
/*
*
*/
.text
SUPERALIGN_TEXT
/*
* 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
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
/*
* Fake clock interrupt(s) so that they appear to come from our caller instead
* of from here, so that system profiling works.
* XXX do this more generally (for all vectors; look up the C entry point).
* XXX frame bogusness stops us from just jumping to the C entry point.
*/
ALIGN_TEXT
vec0:
popl %eax /* return address */
pushfl
pushl $KCSEL
pushl %eax
cli
MEXITCOUNT
jmp _Xintr0 /* XXX might need _Xfastintr0 */
#ifndef PC98
ALIGN_TEXT
vec8:
popl %eax
pushfl
pushl $KCSEL
pushl %eax
cli
MEXITCOUNT
jmp _Xintr8 /* XXX might need _Xfastintr8 */
#endif /* PC98 */
/*
* The 'generic' vector stubs.
*/
#define BUILD_VEC(irq_num) \
ALIGN_TEXT ; \
__CONCAT(vec,irq_num): ; \
int $ICU_OFFSET + (irq_num) ; \
ret
BUILD_VEC(1)
BUILD_VEC(2)
BUILD_VEC(3)
BUILD_VEC(4)
BUILD_VEC(5)
BUILD_VEC(6)
BUILD_VEC(7)
#ifdef PC98
BUILD_VEC(8)
#endif
BUILD_VEC(9)
BUILD_VEC(10)
BUILD_VEC(11)
BUILD_VEC(12)
BUILD_VEC(13)
BUILD_VEC(14)
BUILD_VEC(15)