1*7c478bd9Sstevel@tonic-gate /* 2*7c478bd9Sstevel@tonic-gate * CDDL HEADER START 3*7c478bd9Sstevel@tonic-gate * 4*7c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*7c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*7c478bd9Sstevel@tonic-gate * with the License. 8*7c478bd9Sstevel@tonic-gate * 9*7c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*7c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*7c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 12*7c478bd9Sstevel@tonic-gate * and limitations under the License. 13*7c478bd9Sstevel@tonic-gate * 14*7c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*7c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*7c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*7c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*7c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*7c478bd9Sstevel@tonic-gate * 20*7c478bd9Sstevel@tonic-gate * CDDL HEADER END 21*7c478bd9Sstevel@tonic-gate */ 22*7c478bd9Sstevel@tonic-gate /* 23*7c478bd9Sstevel@tonic-gate * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24*7c478bd9Sstevel@tonic-gate * Use is subject to license terms. 25*7c478bd9Sstevel@tonic-gate */ 26*7c478bd9Sstevel@tonic-gate 27*7c478bd9Sstevel@tonic-gate #include <sys/types.h> 28*7c478bd9Sstevel@tonic-gate #include <sys/param.h> 29*7c478bd9Sstevel@tonic-gate #include <sys/var.h> 30*7c478bd9Sstevel@tonic-gate #include <sys/thread.h> 31*7c478bd9Sstevel@tonic-gate #include <sys/cpuvar.h> 32*7c478bd9Sstevel@tonic-gate #include <sys/kstat.h> 33*7c478bd9Sstevel@tonic-gate #include <sys/uadmin.h> 34*7c478bd9Sstevel@tonic-gate #include <sys/systm.h> 35*7c478bd9Sstevel@tonic-gate #include <sys/errno.h> 36*7c478bd9Sstevel@tonic-gate #include <sys/cmn_err.h> 37*7c478bd9Sstevel@tonic-gate #include <sys/procset.h> 38*7c478bd9Sstevel@tonic-gate #include <sys/processor.h> 39*7c478bd9Sstevel@tonic-gate #include <sys/debug.h> 40*7c478bd9Sstevel@tonic-gate #include <sys/cyclic.h> 41*7c478bd9Sstevel@tonic-gate #include <sys/pool_pset.h> 42*7c478bd9Sstevel@tonic-gate 43*7c478bd9Sstevel@tonic-gate /* 44*7c478bd9Sstevel@tonic-gate * cpu_intr_on - determine whether the CPU is participating 45*7c478bd9Sstevel@tonic-gate * in I/O interrupts. 46*7c478bd9Sstevel@tonic-gate */ 47*7c478bd9Sstevel@tonic-gate int cpu_intr_on(cpu_t * cp)48*7c478bd9Sstevel@tonic-gatecpu_intr_on(cpu_t *cp) 49*7c478bd9Sstevel@tonic-gate { 50*7c478bd9Sstevel@tonic-gate ASSERT(MUTEX_HELD(&cpu_lock)); 51*7c478bd9Sstevel@tonic-gate return ((cp->cpu_flags & CPU_ENABLE) != 0); 52*7c478bd9Sstevel@tonic-gate } 53*7c478bd9Sstevel@tonic-gate 54*7c478bd9Sstevel@tonic-gate /* 55*7c478bd9Sstevel@tonic-gate * Return the next on-line CPU handling interrupts. 56*7c478bd9Sstevel@tonic-gate */ 57*7c478bd9Sstevel@tonic-gate cpu_t * cpu_intr_next(cpu_t * cp)58*7c478bd9Sstevel@tonic-gatecpu_intr_next(cpu_t *cp) 59*7c478bd9Sstevel@tonic-gate { 60*7c478bd9Sstevel@tonic-gate cpu_t *c; 61*7c478bd9Sstevel@tonic-gate 62*7c478bd9Sstevel@tonic-gate ASSERT(MUTEX_HELD(&cpu_lock)); 63*7c478bd9Sstevel@tonic-gate 64*7c478bd9Sstevel@tonic-gate c = cp->cpu_next_onln; 65*7c478bd9Sstevel@tonic-gate while (c != cp) { 66*7c478bd9Sstevel@tonic-gate if (cpu_intr_on(c)) { 67*7c478bd9Sstevel@tonic-gate return (c); 68*7c478bd9Sstevel@tonic-gate } 69*7c478bd9Sstevel@tonic-gate c = c->cpu_next_onln; 70*7c478bd9Sstevel@tonic-gate } 71*7c478bd9Sstevel@tonic-gate return (NULL); 72*7c478bd9Sstevel@tonic-gate } 73*7c478bd9Sstevel@tonic-gate 74*7c478bd9Sstevel@tonic-gate /* 75*7c478bd9Sstevel@tonic-gate * cpu_intr_count - count how many CPUs are handling I/O interrupts. 76*7c478bd9Sstevel@tonic-gate */ 77*7c478bd9Sstevel@tonic-gate int cpu_intr_count(cpu_t * cp)78*7c478bd9Sstevel@tonic-gatecpu_intr_count(cpu_t *cp) 79*7c478bd9Sstevel@tonic-gate { 80*7c478bd9Sstevel@tonic-gate cpu_t *c; 81*7c478bd9Sstevel@tonic-gate int count = 0; 82*7c478bd9Sstevel@tonic-gate 83*7c478bd9Sstevel@tonic-gate ASSERT(MUTEX_HELD(&cpu_lock)); 84*7c478bd9Sstevel@tonic-gate c = cp; 85*7c478bd9Sstevel@tonic-gate do { 86*7c478bd9Sstevel@tonic-gate if (cpu_intr_on(c)) { 87*7c478bd9Sstevel@tonic-gate ++count; 88*7c478bd9Sstevel@tonic-gate } 89*7c478bd9Sstevel@tonic-gate } while ((c = c->cpu_next) != cp); 90*7c478bd9Sstevel@tonic-gate return (count); 91*7c478bd9Sstevel@tonic-gate } 92*7c478bd9Sstevel@tonic-gate 93*7c478bd9Sstevel@tonic-gate /* 94*7c478bd9Sstevel@tonic-gate * Enable I/O interrupts on this CPU, if they are disabled. 95*7c478bd9Sstevel@tonic-gate */ 96*7c478bd9Sstevel@tonic-gate void cpu_intr_enable(cpu_t * cp)97*7c478bd9Sstevel@tonic-gatecpu_intr_enable(cpu_t *cp) 98*7c478bd9Sstevel@tonic-gate { 99*7c478bd9Sstevel@tonic-gate ASSERT(MUTEX_HELD(&cpu_lock)); 100*7c478bd9Sstevel@tonic-gate if (!cpu_intr_on(cp)) { 101*7c478bd9Sstevel@tonic-gate cpu_enable_intr(cp); 102*7c478bd9Sstevel@tonic-gate cpu_set_state(cp); 103*7c478bd9Sstevel@tonic-gate } 104*7c478bd9Sstevel@tonic-gate } 105*7c478bd9Sstevel@tonic-gate 106*7c478bd9Sstevel@tonic-gate /* 107*7c478bd9Sstevel@tonic-gate * cpu_intr_disable - redirect I/O interrupts targetted at this CPU. 108*7c478bd9Sstevel@tonic-gate * 109*7c478bd9Sstevel@tonic-gate * semantics: We check the count of CPUs that are accepting 110*7c478bd9Sstevel@tonic-gate * interrupts, because it's stupid to take the last CPU out 111*7c478bd9Sstevel@tonic-gate * of I/O interrupt participation. This also permits the 112*7c478bd9Sstevel@tonic-gate * p_online syscall to fail gracefully in uniprocessor configurations 113*7c478bd9Sstevel@tonic-gate * without having to perform any special platform-specific operations. 114*7c478bd9Sstevel@tonic-gate */ 115*7c478bd9Sstevel@tonic-gate int cpu_intr_disable(cpu_t * cp)116*7c478bd9Sstevel@tonic-gatecpu_intr_disable(cpu_t *cp) 117*7c478bd9Sstevel@tonic-gate { 118*7c478bd9Sstevel@tonic-gate int e = EBUSY; 119*7c478bd9Sstevel@tonic-gate 120*7c478bd9Sstevel@tonic-gate ASSERT(MUTEX_HELD(&cpu_lock)); 121*7c478bd9Sstevel@tonic-gate if ((cpu_intr_count(cp) > 1) && (cpu_intr_next(cp) != NULL)) { 122*7c478bd9Sstevel@tonic-gate if (cpu_intr_on(cp)) { 123*7c478bd9Sstevel@tonic-gate /* 124*7c478bd9Sstevel@tonic-gate * Juggle away cyclics, but don't fail if we don't 125*7c478bd9Sstevel@tonic-gate * manage to juggle all of them away; we want to allow 126*7c478bd9Sstevel@tonic-gate * CPU-bound cyclics to continue to fire on the 127*7c478bd9Sstevel@tonic-gate * sheltered CPU. 128*7c478bd9Sstevel@tonic-gate */ 129*7c478bd9Sstevel@tonic-gate (void) cyclic_juggle(cp); 130*7c478bd9Sstevel@tonic-gate e = cpu_disable_intr(cp); 131*7c478bd9Sstevel@tonic-gate } 132*7c478bd9Sstevel@tonic-gate } 133*7c478bd9Sstevel@tonic-gate if (e == 0) 134*7c478bd9Sstevel@tonic-gate cpu_set_state(cp); 135*7c478bd9Sstevel@tonic-gate return (e); 136*7c478bd9Sstevel@tonic-gate } 137