cd906fe3de
to use a locked cmpexg when unlocking a lock that we already hold, since
nobody else can touch the lock while we hold it. Second, it is not
necessary to use a locked cmpexg when locking a lock that we already
hold, for the same reason. These changes will allow MP locks to be used
recursively without impacting performance.
Modify two procedures that are called only by assembly and are already
NOPROF entries to pass a critical argument in %edx instead of on the
stack, removing a significant amount of code from the critical path
as a consequence.
Reviewed by: Alfred Perlstein <bright@wintelcom.net>, Peter Wemm <peter@netplex.com.au>
387 lines
9.2 KiB
ArmAsm
387 lines
9.2 KiB
ArmAsm
/*-
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* Copyright (c) 1989, 1990 William F. Jolitz.
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)ipl.s
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*
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* $FreeBSD$
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*/
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/*
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* AT/386
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* Vector interrupt control section
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*/
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.data
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ALIGN_DATA
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/* current priority (all off) */
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.globl _cpl
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_cpl: .long HWI_MASK | SWI_MASK
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.globl _tty_imask
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_tty_imask: .long SWI_TTY_MASK
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.globl _bio_imask
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_bio_imask: .long SWI_CLOCK_MASK | SWI_CAMBIO_MASK
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.globl _net_imask
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_net_imask: .long SWI_NET_MASK | SWI_CAMNET_MASK
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.globl _cam_imask
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_cam_imask: .long SWI_CAMBIO_MASK | SWI_CAMNET_MASK
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.globl _soft_imask
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_soft_imask: .long SWI_MASK
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.globl _softnet_imask
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_softnet_imask: .long SWI_NET_MASK
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.globl _softtty_imask
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_softtty_imask: .long SWI_TTY_MASK
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.globl _astpending
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_astpending: .long 0
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/* pending interrupts blocked by splxxx() */
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.globl _ipending
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_ipending: .long 0
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/* set with bits for which queue to service */
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.globl _netisr
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_netisr: .long 0
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.globl _netisrs
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_netisrs:
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.long dummynetisr, dummynetisr, dummynetisr, dummynetisr
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.text
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#ifdef SMP
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#ifdef notnow
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#define TEST_CIL \
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cmpl $0x0100, _cil ; \
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jne 1f ; \
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cmpl $0, _inside_intr ; \
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jne 1f ; \
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int $3 ; \
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1:
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#else
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#define TEST_CIL
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#endif
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#endif
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/*
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* Handle return from interrupts, traps and syscalls.
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*/
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SUPERALIGN_TEXT
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.type _doreti,@function
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_doreti:
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#ifdef SMP
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TEST_CIL
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#endif
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FAKE_MCOUNT(_bintr) /* init "from" _bintr -> _doreti */
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addl $4,%esp /* discard unit number */
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popl %eax /* cpl or cml to restore */
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doreti_next:
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/*
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* Check for pending HWIs and SWIs atomically with restoring cpl
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* and exiting. The check has to be atomic with exiting to stop
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* (ipending & ~cpl) changing from zero to nonzero while we're
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* looking at it (this wouldn't be fatal but it would increase
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* interrupt latency). Restoring cpl has to be atomic with exiting
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* so that the stack cannot pile up (the nesting level of interrupt
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* handlers is limited by the number of bits in cpl).
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*/
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#ifdef SMP
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TEST_CIL
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cli /* early to prevent INT deadlock */
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pushl %eax /* preserve cpl while getting lock */
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ICPL_LOCK
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popl %eax
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doreti_next2:
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#endif
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movl %eax,%ecx
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#ifdef CPL_AND_CML
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orl _cpl, %ecx /* add cpl to cml */
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#endif
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notl %ecx /* set bit = unmasked level */
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#ifndef SMP
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cli
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#endif
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andl _ipending,%ecx /* set bit = unmasked pending INT */
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jne doreti_unpend
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#ifdef SMP
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TEST_CIL
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#endif
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#ifdef CPL_AND_CML
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movl %eax, _cml
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#else
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movl %eax,_cpl
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#endif
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FAST_ICPL_UNLOCK /* preserves %eax */
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MPLOCKED decb _intr_nesting_level
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/* Check for ASTs that can be handled now. */
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cmpb $0,_astpending
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je doreti_exit
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testb $SEL_RPL_MASK,TF_CS(%esp)
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jne doreti_ast
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testl $PSL_VM,TF_EFLAGS(%esp)
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je doreti_exit
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cmpl $1,_in_vm86call
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jne doreti_ast
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doreti_exit:
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MEXITCOUNT
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#ifdef SMP
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#ifdef INTR_SIMPLELOCK
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#error code needed here to decide which lock to release, INTR or giant
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#endif
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/* release the kernel lock */
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movl $_mp_lock, %edx /* GIANT_LOCK */
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call _MPrellock_edx
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#endif /* SMP */
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.globl doreti_popl_fs
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doreti_popl_fs:
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popl %fs
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.globl doreti_popl_es
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doreti_popl_es:
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popl %es
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.globl doreti_popl_ds
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doreti_popl_ds:
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popl %ds
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popal
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addl $8,%esp
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.globl doreti_iret
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doreti_iret:
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iret
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ALIGN_TEXT
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.globl doreti_iret_fault
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doreti_iret_fault:
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subl $8,%esp
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pushal
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pushl %ds
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.globl doreti_popl_ds_fault
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doreti_popl_ds_fault:
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pushl %es
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.globl doreti_popl_es_fault
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doreti_popl_es_fault:
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pushl %fs
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.globl doreti_popl_fs_fault
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doreti_popl_fs_fault:
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movl $0,TF_ERR(%esp) /* XXX should be the error code */
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movl $T_PROTFLT,TF_TRAPNO(%esp)
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jmp alltraps_with_regs_pushed
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ALIGN_TEXT
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doreti_unpend:
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/*
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* Enabling interrupts is safe because we haven't restored cpl yet.
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* The locking from the "btrl" test is probably no longer necessary.
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* We won't miss any new pending interrupts because we will check
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* for them again.
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*/
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#ifdef SMP
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TEST_CIL
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/* we enter with cpl locked */
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bsfl %ecx, %ecx /* slow, but not worth optimizing */
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lock
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btrl %ecx, _ipending
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jnc doreti_next2 /* some intr cleared memory copy */
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cmpl $NHWI, %ecx
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jae 1f
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btsl %ecx, _cil
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1:
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FAST_ICPL_UNLOCK /* preserves %eax */
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sti /* late to prevent INT deadlock */
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#else
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sti
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bsfl %ecx,%ecx /* slow, but not worth optimizing */
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btrl %ecx,_ipending
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jnc doreti_next /* some intr cleared memory copy */
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#endif /* SMP */
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/*
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* Set up JUMP to _ihandlers[%ecx] for HWIs.
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* Set up CALL of _ihandlers[%ecx] for SWIs.
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* This is a bit early for the SMP case - we have to push %ecx and
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* %edx, but could push only %ecx and load %edx later.
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*/
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movl _ihandlers(,%ecx,4),%edx
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cmpl $NHWI,%ecx
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jae doreti_swi
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cli
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#ifdef SMP
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pushl %edx /* preserve %edx */
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#ifdef APIC_INTR_DIAGNOSTIC
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pushl %ecx
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#endif
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pushl %eax /* preserve %eax */
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ICPL_LOCK
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#ifdef CPL_AND_CML
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popl _cml
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#else
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popl _cpl
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#endif
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FAST_ICPL_UNLOCK
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#ifdef APIC_INTR_DIAGNOSTIC
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popl %ecx
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#endif
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popl %edx
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#else
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movl %eax,_cpl
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#endif
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MEXITCOUNT
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#ifdef APIC_INTR_DIAGNOSTIC
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lock
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incl CNAME(apic_itrace_doreti)(,%ecx,4)
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#ifdef APIC_INTR_DIAGNOSTIC_IRQ
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cmpl $APIC_INTR_DIAGNOSTIC_IRQ,%ecx
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jne 9f
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pushl %eax
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pushl %ecx
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pushl %edx
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pushl $APIC_ITRACE_DORETI
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call log_intr_event
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addl $4,%esp
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popl %edx
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popl %ecx
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popl %eax
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9:
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#endif
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#endif
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jmp %edx
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ALIGN_TEXT
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doreti_swi:
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#ifdef SMP
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TEST_CIL
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#endif
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pushl %eax
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/*
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* At least the SWI_CLOCK handler has to run at a possibly strictly
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* lower cpl, so we have to restore
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* all the h/w bits in cpl now and have to worry about stack growth.
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* The worst case is currently (30 Jan 1994) 2 SWI handlers nested
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* in dying interrupt frames and about 12 HWIs nested in active
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* interrupt frames. There are only 4 different SWIs and the HWI
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* and SWI masks limit the nesting further.
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*/
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#ifdef SMP
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orl imasks(,%ecx,4), %eax
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pushl %ecx /* preserve for use by _swi_generic */
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pushl %edx /* save handler entry point */
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cli /* prevent INT deadlock */
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pushl %eax /* save cpl|cml */
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ICPL_LOCK
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#ifdef CPL_AND_CML
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popl _cml /* restore cml */
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#else
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popl _cpl /* restore cpl */
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#endif
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FAST_ICPL_UNLOCK
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sti
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popl %edx /* restore handler entry point */
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popl %ecx
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#else
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orl imasks(,%ecx,4),%eax
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movl %eax,_cpl
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#endif
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call %edx
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popl %eax
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jmp doreti_next
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ALIGN_TEXT
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doreti_ast:
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movl $0,_astpending
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sti
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movl $T_ASTFLT,TF_TRAPNO(%esp)
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call _trap
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subl %eax,%eax /* recover cpl|cml */
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#ifdef CPL_AND_CML
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movl %eax, _cpl
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#endif
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movb $1,_intr_nesting_level /* for doreti_next to decrement */
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jmp doreti_next
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ALIGN_TEXT
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swi_net:
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MCOUNT
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bsfl _netisr,%eax
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je swi_net_done
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swi_net_more:
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btrl %eax,_netisr
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jnc swi_net_next
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call *_netisrs(,%eax,4)
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swi_net_next:
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bsfl _netisr,%eax
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jne swi_net_more
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swi_net_done:
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ret
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ALIGN_TEXT
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dummynetisr:
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MCOUNT
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ret
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/*
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* The arg is in a nonstandard place, so swi_dispatcher() can't be called
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* directly and swi_generic() can't use ENTRY() or MCOUNT.
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*/
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ALIGN_TEXT
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.globl _swi_generic
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.type _swi_generic,@function
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_swi_generic:
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pushl %ecx
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FAKE_MCOUNT(4(%esp))
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call _swi_dispatcher
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popl %ecx
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ret
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ENTRY(swi_null)
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ret
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#ifdef APIC_IO
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#include "i386/isa/apic_ipl.s"
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#else
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#include "i386/isa/icu_ipl.s"
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#endif /* APIC_IO */
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