1/* $NetBSD: vr_idle.S,v 1.6 2000/08/20 21:50:08 thorpej Exp $ */ 2 3/* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Digital Equipment Corporation and Ralph Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * Copyright (C) 1989 Digital Equipment Corporation. 39 * Permission to use, copy, modify, and distribute this software and 40 * its documentation for any purpose and without fee is hereby granted, 41 * provided that the above copyright notice appears in all copies. 42 * Digital Equipment Corporation makes no representations about the 43 * suitability of this software for any purpose. It is provided "as is" 44 * without express or implied warranty. 45 * 46 */ 47 48#include <mips/asm.h> 49#include <mips/cpuregs.h> 50#include <hpcmips/vr/vr_asm.h> 51 52#include "opt_lockdebug.h" 53 54#include "assym.h" 55 56 .set noreorder 57 58/* 59 * When no processes are on the runq, cpu_switch branches to idle 60 * to wait for something to come ready. 61 * Note: this is really a part of cpu_switch() but defined here for kernel 62 * profiling. 63 */ 64LEAF(vr_idle) 65 li t0, (MIPS_INT_MASK | MIPS_SR_INT_IE) 66 mtc0 t0, MIPS_COP_0_STATUS # enable all interrupts 67 nop 68 sw zero, _C_LABEL(curproc) # set curproc NULL for stats 69#if defined(LOCKDEBUG) 70 jal _C_LABEL(sched_unlock_idle) # release sched_lock 71 nop 72#endif 73 74 /* Try to zero some free pages. */ 75 lw t0, _C_LABEL(uvm) + UVM_PAGE_IDLE_ZERO 76 nop 77 beq t0, zero, 1f 78 nop 79 jal _C_LABEL(uvm_pageidlezero) 80 nop 811: 82 lw t0, _C_LABEL(sched_whichqs) # look for non-empty queue 83 bne t0, zero, 1f 84 nop 85 .word VR_OPCODE_STANDBY 86 nop 87 nop 88 nop 89 nop 90 beq t0, zero, 1b 91 nop 921: 93#if defined(LOCKDEBUG) 94 mtc0 zero, MIPS_COP_0_STATUS # disable all interrupts 95 nop 96 nop 97 nop 98 nop 99 jal _C_LABEL(sched_lock_idle) # acquire sched_lock 100 nop 101 la ra, cpu_switch_queuescan # rathole to cpu_switch() 102 j ra 103 nop 104#else 105 mtc0 zero, MIPS_COP_0_STATUS # disable all interrupts 106 nop 107 nop 108 nop 109 la ra, cpu_switch_queuescan # rathole to cpu_switch() 110 j ra 111 nop 112#endif 113END(vr_idle) 114