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36e9f877df
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
119 lines
4.7 KiB
C
119 lines
4.7 KiB
C
/*-
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* Copyright (c) 1993 The Regents of the University of California.
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* All rights reserved.
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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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* $FreeBSD$
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*/
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#ifndef _MACHINE_IPL_H_
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#define _MACHINE_IPL_H_
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#ifdef APIC_IO
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#include <i386/isa/apic_ipl.h>
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#else
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#include <i386/isa/icu_ipl.h>
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#endif
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/*
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* Software interrupt bit numbers in priority order. The priority only
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* determines which swi will be dispatched next; a higher priority swi
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* may be dispatched when a nested h/w interrupt handler returns.
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*/
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#define SWI_TTY (NHWI + 0)
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#define SWI_NET (NHWI + 1)
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#define SWI_CAMNET (NHWI + 2)
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#define SWI_CAMBIO (NHWI + 3)
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#define SWI_VM (NHWI + 4)
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#define SWI_CLOCK 30
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#define NSWI (32 - NHWI)
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/*
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* Corresponding interrupt-pending bits for ipending.
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*/
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#define SWI_TTY_PENDING (1 << SWI_TTY)
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#define SWI_NET_PENDING (1 << SWI_NET)
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#define SWI_CAMNET_PENDING (1 << SWI_CAMNET)
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#define SWI_CAMBIO_PENDING (1 << SWI_CAMBIO)
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#define SWI_VM_PENDING (1 << SWI_VM)
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#define SWI_CLOCK_PENDING (1 << SWI_CLOCK)
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/*
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* Corresponding interrupt-disable masks for cpl. The ordering is now by
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* inclusion (where each mask is considered as a set of bits). Everything
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* includes SWI_CLOCK_MASK so that softclock() doesn't
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* run while other swi handlers are running and timeout routines can call
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* swi handlers.
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* SWI_TTY_MASK includes SWI_NET_MASK
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* in case tty interrupts are processed at splsofttty() for a tty that is in
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* SLIP or PPP line discipline (this is weaker than merging net_imask with
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* tty_imask in isa.c - splimp() must mask hard and soft tty interrupts, but
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* spltty() apparently only needs to mask soft net interrupts).
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*/
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#define SWI_TTY_MASK (SWI_TTY_PENDING | SWI_CLOCK_MASK | SWI_NET_MASK)
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#define SWI_CAMNET_MASK (SWI_CAMNET_PENDING | SWI_CLOCK_MASK)
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#define SWI_CAMBIO_MASK (SWI_CAMBIO_PENDING | SWI_CLOCK_MASK)
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#define SWI_NET_MASK (SWI_NET_PENDING | SWI_CLOCK_MASK)
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#define SWI_VM_MASK (SWI_VM_PENDING | SWI_CLOCK_MASK)
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#define SWI_CLOCK_MASK SWI_CLOCK_PENDING
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#define SWI_MASK (~HWI_MASK)
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/*
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* astpending bits
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*/
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#define AST_PENDING 0x00000001
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#define AST_RESCHED 0x00000002
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#ifndef LOCORE
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/*
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* cpl is preserved by interrupt handlers so it is effectively nonvolatile.
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* ipending and idelayed are changed by interrupt handlers so they are
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* volatile.
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*/
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#ifdef notyet /* in <sys/interrupt.h> until pci drivers stop hacking on them */
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extern unsigned bio_imask; /* group of interrupts masked with splbio() */
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#endif
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extern unsigned cpl; /* current priority level mask */
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#ifdef SMP
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extern unsigned cil; /* current INTerrupt level mask */
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#endif
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extern volatile unsigned idelayed; /* interrupts to become pending */
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extern volatile unsigned ipending; /* active interrupts masked by cpl */
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#ifdef notyet /* in <sys/systm.h> until pci drivers stop hacking on them */
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extern unsigned net_imask; /* group of interrupts masked with splimp() */
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extern unsigned stat_imask; /* interrupts masked with splstatclock() */
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extern unsigned tty_imask; /* group of interrupts masked with spltty() */
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#endif
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#endif /* !LOCORE */
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#endif /* !_MACHINE_IPL_H_ */
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