1 /* $NetBSD: xen_intr.c,v 1.9 2009/01/16 20:16:47 jym 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 1.9 2009/01/16 20:16:47 jym 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 if (ci->ci_ilevel <= nlevel) 68 return; 69 70 __insn_barrier(); 71 72 imask = IUNMASK(ci, nlevel); 73 psl = x86_read_psl(); 74 x86_disable_intr(); 75 if (ci->ci_ipending & imask) { 76 KASSERT(psl == 0); 77 Xspllower(nlevel); 78 /* Xspllower does enable_intr() */ 79 } else { 80 ci->ci_ilevel = nlevel; 81 x86_write_psl(psl); 82 } 83 } 84 85 void 86 x86_disable_intr(void) 87 { 88 __cli(); 89 } 90 91 void 92 x86_enable_intr(void) 93 { 94 __sti(); 95 } 96 97 u_long 98 x86_read_psl(void) 99 { 100 101 return (curcpu()->ci_vcpu->evtchn_upcall_mask); 102 } 103 104 void 105 x86_write_psl(u_long psl) 106 { 107 struct cpu_info *ci = curcpu(); 108 109 ci->ci_vcpu->evtchn_upcall_mask = psl; 110 xen_rmb(); 111 if (ci->ci_vcpu->evtchn_upcall_pending && psl == 0) { 112 hypervisor_force_callback(); 113 } 114 } 115