1 /* $NetBSD: xen_intr.c,v 1.5 2008/04/28 20:23:40 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum, and by Jason R. Thorpe. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: xen_intr.c,v 1.5 2008/04/28 20:23:40 martin Exp $"); 34 35 #include <sys/param.h> 36 37 #include <machine/cpu.h> 38 #include <machine/intr.h> 39 40 /* 41 * Add a mask to cpl, and return the old value of cpl. 42 */ 43 int 44 splraise(int nlevel) 45 { 46 int olevel; 47 struct cpu_info *ci = curcpu(); 48 49 olevel = ci->ci_ilevel; 50 if (nlevel > olevel) 51 ci->ci_ilevel = nlevel; 52 __insn_barrier(); 53 return (olevel); 54 } 55 56 /* 57 * Restore a value to cpl (unmasking interrupts). If any unmasked 58 * interrupts are pending, call Xspllower() to process them. 59 */ 60 void 61 spllower(int nlevel) 62 { 63 struct cpu_info *ci = curcpu(); 64 uint32_t imask; 65 u_long psl; 66 67 __insn_barrier(); 68 69 imask = IUNMASK(ci, nlevel); 70 psl = x86_read_psl(); 71 x86_disable_intr(); 72 if (ci->ci_ipending & imask) { 73 Xspllower(nlevel); 74 /* Xspllower does enable_intr() */ 75 } else { 76 ci->ci_ilevel = nlevel; 77 x86_write_psl(psl); 78 } 79 } 80 81 #ifndef __x86_64__ 82 83 /* 84 * Software interrupt registration 85 * 86 * We hand-code this to ensure that it's atomic. 87 * 88 * XXX always scheduled on the current CPU. 89 */ 90 void 91 softintr(int sir) 92 { 93 struct cpu_info *ci = curcpu(); 94 95 __asm volatile("orl %1, %0" : "=m"(ci->ci_ipending) : "ir" (1 << sir)); 96 } 97 #endif 98 99 void 100 x86_disable_intr(void) 101 { 102 __cli(); 103 } 104 105 void 106 x86_enable_intr(void) 107 { 108 __sti(); 109 } 110 111 u_long 112 x86_read_psl(void) 113 { 114 115 return (curcpu()->ci_vcpu->evtchn_upcall_mask); 116 } 117 118 void 119 x86_write_psl(u_long psl) 120 { 121 struct cpu_info *ci = curcpu(); 122 123 ci->ci_vcpu->evtchn_upcall_mask = psl; 124 x86_lfence(); 125 if (ci->ci_vcpu->evtchn_upcall_pending && psl == 0) { 126 hypervisor_force_callback(); 127 } 128 } 129