freebsd-skq/sys/i386/isa/apic_ipl.s
Matthew Dillon 36e9f877df Commit major SMP cleanups and move the BGL (big giant lock) in the
syscall path inward.  A system call may select whether it needs the MP
    lock or not (the default being that it does need it).

    A great deal of conditional SMP code for various deadended experiments
    has been removed.  'cil' and 'cml' have been removed entirely, and the
    locking around the cpl has been removed.  The conditional
    separately-locked fast-interrupt code has been removed, meaning that
    interrupts must hold the CPL now (but they pretty much had to anyway).
    Another reason for doing this is that the original separate-lock for
    interrupts just doesn't apply to the interrupt thread mechanism being
    contemplated.

    Modifications to the cpl may now ONLY occur while holding the MP
    lock.  For example, if an otherwise MP safe syscall needs to mess with
    the cpl, it must hold the MP lock for the duration and must (as usual)
    save/restore the cpl in a nested fashion.

    This is precursor work for the real meat coming later: avoiding having
    to hold the MP lock for common syscalls and I/O's and interrupt threads.
    It is expected that the spl mechanisms and new interrupt threading
    mechanisms will be able to run in tandem, allowing a slow piecemeal
    transition to occur.

    This patch should result in a moderate performance improvement due to
    the considerable amount of code that has been removed from the critical
    path, especially the simplification of the spl*() calls.  The real
    performance gains will come later.

Approved by: jkh
Reviewed by: current, bde (exception.s)
Some work taken from: luoqi's patch
2000-03-28 07:16:37 +00:00

456 lines
12 KiB
ArmAsm

/*-
* Copyright (c) 1997, by Steve Passe
* 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. The name of the developer may NOT be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
.data
ALIGN_DATA
/*
* Routines used by splz_unpend to build an interrupt frame from a
* trap frame. The _vec[] routines build the proper frame on the stack,
* then call one of _Xintr0 thru _XintrNN.
*
* used by:
* i386/isa/apic_ipl.s (this file): splz_unpend JUMPs to HWIs.
* i386/isa/clock.c: setup _vec[clock] to point at _vec8254.
*/
.globl _vec
_vec:
.long vec0, vec1, vec2, vec3, vec4, vec5, vec6, vec7
.long vec8, vec9, vec10, vec11, vec12, vec13, vec14, vec15
.long vec16, vec17, vec18, vec19, vec20, vec21, vec22, vec23
/*
* Note:
* This is the UP equivilant of _imen.
* It is OPAQUE, and must NOT be accessed directly.
* It MUST be accessed along with the IO APIC as a 'critical region'.
* Accessed by:
* INTREN()
* INTRDIS()
* MAYBE_MASK_IRQ
* MAYBE_UNMASK_IRQ
* imen_dump()
*/
.p2align 2 /* MUST be 32bit aligned */
.globl _apic_imen
_apic_imen:
.long HWI_MASK
/*
*
*/
.text
SUPERALIGN_TEXT
/*
* splz() - dispatch pending interrupts after cpl reduced
*
* 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. However, since ipending can change at any time
* (by an interrupt or, with SMP, by another cpu), we have to
* repeat the check. At the moment we must own the MP lock in
* the SMP case because the interruput handlers require it. We
* loop until no unmasked pending interrupts remain.
*
* No new unmaksed pending interrupts will be added during the
* loop because, being unmasked, the interrupt code will be able
* to execute the interrupts.
*
* Interrupts come in two flavors: Hardware interrupts and software
* interrupts. We have to detect the type of interrupt (based on the
* position of the interrupt bit) and call the appropriate dispatch
* routine.
*
* NOTE: "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 /* set bit = unmasked level */
andl _ipending,%ecx /* set bit = unmasked pending INT */
jne splz_unpend
ret
ALIGN_TEXT
splz_unpend:
bsfl %ecx,%ecx
lock
btrl %ecx,_ipending
jnc splz_next
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.
*
* The vec[] routines build the proper frame on the stack,
* then call one of _Xintr0 thru _XintrNN.
*/
jmp *_vec(,%ecx,4)
ALIGN_TEXT
splz_swi:
pushl %eax
orl imasks(,%ecx,4),%eax
movl %eax,_cpl
call *_ihandlers(,%ecx,4)
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.
* We have to clear iactive since this is an unpend call, and it will be
* set from the time of the original INT.
*/
/*
* The 'generic' vector stubs.
*/
#define BUILD_VEC(irq_num) \
ALIGN_TEXT ; \
__CONCAT(vec,irq_num): ; \
popl %eax ; \
pushfl ; \
pushl $KCSEL ; \
pushl %eax ; \
cli ; \
lock ; /* MP-safe */ \
andl $~IRQ_BIT(irq_num), iactive ; /* lazy masking */ \
MEXITCOUNT ; \
APIC_ITRACE(apic_itrace_splz, irq_num, APIC_ITRACE_SPLZ) ; \
jmp __CONCAT(_Xintr,irq_num)
BUILD_VEC(0)
BUILD_VEC(1)
BUILD_VEC(2)
BUILD_VEC(3)
BUILD_VEC(4)
BUILD_VEC(5)
BUILD_VEC(6)
BUILD_VEC(7)
BUILD_VEC(8)
BUILD_VEC(9)
BUILD_VEC(10)
BUILD_VEC(11)
BUILD_VEC(12)
BUILD_VEC(13)
BUILD_VEC(14)
BUILD_VEC(15)
BUILD_VEC(16) /* 8 additional INTs in IO APIC */
BUILD_VEC(17)
BUILD_VEC(18)
BUILD_VEC(19)
BUILD_VEC(20)
BUILD_VEC(21)
BUILD_VEC(22)
BUILD_VEC(23)
/******************************************************************************
* XXX FIXME: figure out where these belong.
*/
/* this nonsense is to verify that masks ALWAYS have 1 and only 1 bit set */
#define QUALIFY_MASKS_NOT
#ifdef QUALIFY_MASKS
#define QUALIFY_MASK \
btrl %ecx, %eax ; \
andl %eax, %eax ; \
jz 1f ; \
pushl $bad_mask ; \
call _panic ; \
1:
bad_mask: .asciz "bad mask"
#else
#define QUALIFY_MASK
#endif
/*
* (soon to be) MP-safe function to clear ONE INT mask bit.
* The passed arg is a 32bit u_int MASK.
* It sets the associated bit in _apic_imen.
* It sets the mask bit of the associated IO APIC register.
*/
ENTRY(INTREN)
pushfl /* save state of EI flag */
cli /* prevent recursion */
IMASK_LOCK /* enter critical reg */
movl 8(%esp), %eax /* mask into %eax */
bsfl %eax, %ecx /* get pin index */
btrl %ecx, _apic_imen /* update _apic_imen */
QUALIFY_MASK
shll $4, %ecx
movl CNAME(int_to_apicintpin) + 8(%ecx), %edx
movl CNAME(int_to_apicintpin) + 12(%ecx), %ecx
testl %edx, %edx
jz 1f
movl %ecx, (%edx) /* write the target register index */
movl 16(%edx), %eax /* read the target register data */
andl $~IOART_INTMASK, %eax /* clear mask bit */
movl %eax, 16(%edx) /* write the APIC register data */
1:
IMASK_UNLOCK /* exit critical reg */
popfl /* restore old state of EI flag */
ret
/*
* (soon to be) MP-safe function to set ONE INT mask bit.
* The passed arg is a 32bit u_int MASK.
* It clears the associated bit in _apic_imen.
* It clears the mask bit of the associated IO APIC register.
*/
ENTRY(INTRDIS)
pushfl /* save state of EI flag */
cli /* prevent recursion */
IMASK_LOCK /* enter critical reg */
movl 8(%esp), %eax /* mask into %eax */
bsfl %eax, %ecx /* get pin index */
btsl %ecx, _apic_imen /* update _apic_imen */
QUALIFY_MASK
shll $4, %ecx
movl CNAME(int_to_apicintpin) + 8(%ecx), %edx
movl CNAME(int_to_apicintpin) + 12(%ecx), %ecx
testl %edx, %edx
jz 1f
movl %ecx, (%edx) /* write the target register index */
movl 16(%edx), %eax /* read the target register data */
orl $IOART_INTMASK, %eax /* set mask bit */
movl %eax, 16(%edx) /* write the APIC register data */
1:
IMASK_UNLOCK /* exit critical reg */
popfl /* restore old state of EI flag */
ret
/******************************************************************************
*
*/
/*
* void write_ioapic_mask(int apic, u_int mask);
*/
#define _INT_MASK 0x00010000
#define _PIN_MASK 0x00ffffff
#define _OLD_ESI 0(%esp)
#define _OLD_EBX 4(%esp)
#define _RETADDR 8(%esp)
#define _APIC 12(%esp)
#define _MASK 16(%esp)
ALIGN_TEXT
write_ioapic_mask:
pushl %ebx /* scratch */
pushl %esi /* scratch */
movl _apic_imen, %ebx
xorl _MASK, %ebx /* %ebx = _apic_imen ^ mask */
andl $_PIN_MASK, %ebx /* %ebx = _apic_imen & 0x00ffffff */
jz all_done /* no change, return */
movl _APIC, %esi /* APIC # */
movl _ioapic(,%esi,4), %esi /* %esi holds APIC base address */
next_loop: /* %ebx = diffs, %esi = APIC base */
bsfl %ebx, %ecx /* %ecx = index if 1st/next set bit */
jz all_done
btrl %ecx, %ebx /* clear this bit in diffs */
leal 16(,%ecx,2), %edx /* calculate register index */
movl %edx, (%esi) /* write the target register index */
movl 16(%esi), %eax /* read the target register data */
btl %ecx, _MASK /* test for mask or unmask */
jnc clear /* bit is clear */
orl $_INT_MASK, %eax /* set mask bit */
jmp write
clear: andl $~_INT_MASK, %eax /* clear mask bit */
write: movl %eax, 16(%esi) /* write the APIC register data */
jmp next_loop /* try another pass */
all_done:
popl %esi
popl %ebx
ret
#undef _OLD_ESI
#undef _OLD_EBX
#undef _RETADDR
#undef _APIC
#undef _MASK
#undef _PIN_MASK
#undef _INT_MASK
#ifdef oldcode
_INTREN:
movl _apic_imen, %eax
notl %eax /* mask = ~mask */
andl _apic_imen, %eax /* %eax = _apic_imen & ~mask */
pushl %eax /* new (future) _apic_imen value */
pushl $0 /* APIC# arg */
call write_ioapic_mask /* modify the APIC registers */
addl $4, %esp /* remove APIC# arg from stack */
popl _apic_imen /* _apic_imen |= mask */
ret
_INTRDIS:
movl _apic_imen, %eax
orl 4(%esp), %eax /* %eax = _apic_imen | mask */
pushl %eax /* new (future) _apic_imen value */
pushl $0 /* APIC# arg */
call write_ioapic_mask /* modify the APIC registers */
addl $4, %esp /* remove APIC# arg from stack */
popl _apic_imen /* _apic_imen |= mask */
ret
#endif /* oldcode */
#ifdef ready
/*
* u_int read_io_apic_mask(int apic);
*/
ALIGN_TEXT
read_io_apic_mask:
ret
/*
* Set INT mask bit for each bit set in 'mask'.
* Ignore INT mask bit for all others.
*
* void set_io_apic_mask(apic, u_int32_t bits);
*/
ALIGN_TEXT
set_io_apic_mask:
ret
/*
* void set_ioapic_maskbit(int apic, int bit);
*/
ALIGN_TEXT
set_ioapic_maskbit:
ret
/*
* Clear INT mask bit for each bit set in 'mask'.
* Ignore INT mask bit for all others.
*
* void clr_io_apic_mask(int apic, u_int32_t bits);
*/
ALIGN_TEXT
clr_io_apic_mask:
ret
/*
* void clr_ioapic_maskbit(int apic, int bit);
*/
ALIGN_TEXT
clr_ioapic_maskbit:
ret
#endif /** ready */
/******************************************************************************
*
*/
/*
* u_int io_apic_write(int apic, int select);
*/
ENTRY(io_apic_read)
movl 4(%esp), %ecx /* APIC # */
movl _ioapic(,%ecx,4), %edx /* APIC base register address */
movl 8(%esp), %eax /* target register index */
movl %eax, (%edx) /* write the target register index */
movl 16(%edx), %eax /* read the APIC register data */
ret /* %eax = register value */
/*
* void io_apic_write(int apic, int select, int value);
*/
ENTRY(io_apic_write)
movl 4(%esp), %ecx /* APIC # */
movl _ioapic(,%ecx,4), %edx /* APIC base register address */
movl 8(%esp), %eax /* target register index */
movl %eax, (%edx) /* write the target register index */
movl 12(%esp), %eax /* target register value */
movl %eax, 16(%edx) /* write the APIC register data */
ret /* %eax = void */
/*
* Send an EOI to the local APIC.
*/
ENTRY(apic_eoi)
movl $0, _lapic+0xb0
ret