summaryrefslogtreecommitdiffstats
path: root/arch/x86/xen/platform-pci-unplug.c
blob: 554c002a1e1afcd13a71c90a25eff86057e56832 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/******************************************************************************
 * platform-pci-unplug.c
 *
 * Xen platform PCI device driver
 * Copyright (c) 2010, Citrix
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 */

#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>

#include <xen/platform_pci.h>

#define XEN_PLATFORM_ERR_MAGIC -1
#define XEN_PLATFORM_ERR_PROTOCOL -2
#define XEN_PLATFORM_ERR_BLACKLIST -3

/* store the value of xen_emul_unplug after the unplug is done */
int xen_platform_pci_unplug;
EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
#ifdef CONFIG_XEN_PVHVM
static int xen_emul_unplug;

static int __init check_platform_magic(void)
{
	short magic;
	char protocol;

	magic = inw(XEN_IOPORT_MAGIC);
	if (magic != XEN_IOPORT_MAGIC_VAL) {
		printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n");
		return XEN_PLATFORM_ERR_MAGIC;
	}

	protocol = inb(XEN_IOPORT_PROTOVER);

	printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n",
			protocol);

	switch (protocol) {
	case 1:
		outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM);
		outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER);
		if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) {
			printk(KERN_ERR "Xen Platform: blacklisted by host\n");
			return XEN_PLATFORM_ERR_BLACKLIST;
		}
		break;
	default:
		printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
		return XEN_PLATFORM_ERR_PROTOCOL;
	}

	return 0;
}

void __init xen_unplug_emulated_devices(void)
{
	int r;

	/* check the version of the xen platform PCI device */
	r = check_platform_magic();
	/* If the version matches enable the Xen platform PCI driver.
	 * Also enable the Xen platform PCI driver if the version is really old
	 * and the user told us to ignore it. */
	if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
			(xen_emul_unplug & XEN_UNPLUG_IGNORE)))
		return;
	/* Set the default value of xen_emul_unplug depending on whether or
	 * not the Xen PV frontends and the Xen platform PCI driver have
	 * been compiled for this kernel (modules or built-in are both OK). */
	if (!xen_emul_unplug) {
		if (xen_must_unplug_nics()) {
			printk(KERN_INFO "Netfront and the Xen platform PCI driver have "
					"been compiled for this kernel: unplug emulated NICs.\n");
			xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
		}
		if (xen_must_unplug_disks()) {
			printk(KERN_INFO "Blkfront and the Xen platform PCI driver have "
					"been compiled for this kernel: unplug emulated disks.\n"
					"You might have to change the root device\n"
					"from /dev/hd[a-d] to /dev/xvd[a-d]\n"
					"in your root= kernel command line option\n");
			xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
		}
	}
	/* Now unplug the emulated devices */
	if (!(xen_emul_unplug & XEN_UNPLUG_IGNORE))
		outw(xen_emul_unplug, XEN_IOPORT_UNPLUG);
	xen_platform_pci_unplug = xen_emul_unplug;
}

static int __init parse_xen_emul_unplug(char *arg)
{
	char *p, *q;
	int l;

	for (p = arg; p; p = q) {
		q = strchr(p, ',');
		if (q) {
			l = q - p;
			q++;
		} else {
			l = strlen(p);
		}
		if (!strncmp(p, "all", l))
			xen_emul_unplug |= XEN_UNPLUG_ALL;
		else if (!strncmp(p, "ide-disks", l))
			xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
		else if (!strncmp(p, "aux-ide-disks", l))
			xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS;
		else if (!strncmp(p, "nics", l))
			xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
		else if (!strncmp(p, "ignore", l))
			xen_emul_unplug |= XEN_UNPLUG_IGNORE;
		else
			printk(KERN_WARNING "unrecognised option '%s' "
				 "in parameter 'xen_emul_unplug'\n", p);
	}
	return 0;
}
early_param("xen_emul_unplug", parse_xen_emul_unplug);
#endif