1/*	$NetBSD: xen_intr.c,v 1.8 2008/07/01 18:44:50 bouyer 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 1.8 2008/07/01 18:44:50 bouyer 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