NetBSD/sys/arch/hpcmips/vr/vr_idle.S
thorpej a86d1f4891 Add a lock around the scheduler, and use it as necessary, including
in the non-MULTIPROCESSOR case (LOCKDEBUG requires it).  Scheduler
lock is held upon entry to mi_switch() and cpu_switch(), and
cpu_switch() releases the lock before returning.

Largely from Bill Sommerfeld, with some minor bug fixes and
machine-dependent code hacking from me.
2000-08-20 21:50:06 +00:00

114 lines
3.7 KiB
ArmAsm

/* $NetBSD: vr_idle.S,v 1.6 2000/08/20 21:50:08 thorpej Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Digital Equipment Corporation and Ralph Campbell.
*
* 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.
*
* Copyright (C) 1989 Digital Equipment Corporation.
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies.
* Digital Equipment Corporation makes no representations about the
* suitability of this software for any purpose. It is provided "as is"
* without express or implied warranty.
*
*/
#include <mips/asm.h>
#include <mips/cpuregs.h>
#include <hpcmips/vr/vr_asm.h>
#include "opt_lockdebug.h"
#include "assym.h"
.set noreorder
/*
* When no processes are on the runq, cpu_switch branches to idle
* to wait for something to come ready.
* Note: this is really a part of cpu_switch() but defined here for kernel
* profiling.
*/
LEAF(vr_idle)
li t0, (MIPS_INT_MASK | MIPS_SR_INT_IE)
mtc0 t0, MIPS_COP_0_STATUS # enable all interrupts
nop
sw zero, _C_LABEL(curproc) # set curproc NULL for stats
#if defined(LOCKDEBUG)
jal _C_LABEL(sched_unlock_idle) # release sched_lock
nop
#endif
/* Try to zero some free pages. */
lw t0, _C_LABEL(uvm) + UVM_PAGE_IDLE_ZERO
nop
beq t0, zero, 1f
nop
jal _C_LABEL(uvm_pageidlezero)
nop
1:
lw t0, _C_LABEL(sched_whichqs) # look for non-empty queue
bne t0, zero, 1f
nop
.word VR_OPCODE_STANDBY
nop
nop
nop
nop
beq t0, zero, 1b
nop
1:
#if defined(LOCKDEBUG)
mtc0 zero, MIPS_COP_0_STATUS # disable all interrupts
nop
nop
nop
nop
jal _C_LABEL(sched_lock_idle) # acquire sched_lock
nop
la ra, cpu_switch_queuescan # rathole to cpu_switch()
j ra
nop
#else
mtc0 zero, MIPS_COP_0_STATUS # disable all interrupts
nop
nop
nop
la ra, cpu_switch_queuescan # rathole to cpu_switch()
j ra
nop
#endif
END(vr_idle)