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 */
43int
44splraise(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 */
60void
61spllower(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
85void
86x86_disable_intr(void)
87{
88 __cli();
89}
90
91void
92x86_enable_intr(void)
93{
94 __sti();
95}
96
97u_long
98x86_read_psl(void)
99{
100
101 return (curcpu()->ci_vcpu->evtchn_upcall_mask);
102}
103
104void
105x86_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