xref: /NextBSD/sys/dev/xen/pvcpu/pvcpu.c (revision e5d2f8730c92c4abb6de986ec4e1f39a242b9868)
1 /*
2  * Copyright (c) 2013 Roger Pau Monné <roger.pau@citrix.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/pcpu.h>
36 #include <sys/smp.h>
37 
38 #include <xen/xen-os.h>
39 
40 /*
41  * Dummy Xen cpu device
42  *
43  * Since there's no ACPI on PVH guests, we need to create a dummy
44  * CPU device in order to fill the pcpu->pc_device field.
45  */
46 
47 static void
xenpvcpu_identify(driver_t * driver,device_t parent)48 xenpvcpu_identify(driver_t *driver, device_t parent)
49 {
50 	int i;
51 
52 	/* Only attach to PV guests, HVM guests use the ACPI CPU devices */
53 	if (!xen_pv_domain())
54 		return;
55 
56 	CPU_FOREACH(i) {
57 		if (BUS_ADD_CHILD(parent, 0, "pvcpu", i) == NULL)
58 			panic("Unable to add Xen PV CPU device.");
59 	}
60 }
61 
62 static int
xenpvcpu_probe(device_t dev)63 xenpvcpu_probe(device_t dev)
64 {
65 
66 	device_set_desc(dev, "Xen PV CPU");
67 	return (BUS_PROBE_NOWILDCARD);
68 }
69 
70 static int
xenpvcpu_attach(device_t dev)71 xenpvcpu_attach(device_t dev)
72 {
73 	struct pcpu *pc;
74 	int cpu;
75 
76 	cpu = device_get_unit(dev);
77 	pc = pcpu_find(cpu);
78 	pc->pc_device = dev;
79 	return (0);
80 }
81 
82 static device_method_t xenpvcpu_methods[] = {
83 	DEVMETHOD(device_identify, xenpvcpu_identify),
84 	DEVMETHOD(device_probe, xenpvcpu_probe),
85 	DEVMETHOD(device_attach, xenpvcpu_attach),
86 
87 	DEVMETHOD_END
88 };
89 
90 static driver_t xenpvcpu_driver = {
91 	"pvcpu",
92 	xenpvcpu_methods,
93 	0,
94 };
95 
96 devclass_t xenpvcpu_devclass;
97 
98 DRIVER_MODULE(xenpvcpu, xenpv, xenpvcpu_driver, xenpvcpu_devclass, 0, 0);
99 MODULE_DEPEND(xenpvcpu, xenpv, 1, 1, 1);
100