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 | |