1 /******************************************************************************
2 * platform-pci-unplug.c
4 * Xen platform PCI device driver
5 * Copyright (c) 2010, Citrix
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
18 * Place - Suite 330, Boston, MA 02111-1307 USA.
22 #include <linux/init.h>
24 #include <linux/module.h>
26 #include <xen/platform_pci.h>
29 #define XEN_PLATFORM_ERR_MAGIC -1
30 #define XEN_PLATFORM_ERR_PROTOCOL -2
31 #define XEN_PLATFORM_ERR_BLACKLIST -3
33 /* store the value of xen_emul_unplug after the unplug is done */
34 int xen_platform_pci_unplug;
35 EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
36 #ifdef CONFIG_XEN_PVHVM
37 static int xen_emul_unplug;
39 static int check_platform_magic(void)
44 magic = inw(XEN_IOPORT_MAGIC);
45 if (magic != XEN_IOPORT_MAGIC_VAL) {
46 printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n");
47 return XEN_PLATFORM_ERR_MAGIC;
50 protocol = inb(XEN_IOPORT_PROTOVER);
52 printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n",
57 outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM);
58 outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER);
59 if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) {
60 printk(KERN_ERR "Xen Platform: blacklisted by host\n");
61 return XEN_PLATFORM_ERR_BLACKLIST;
65 printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
66 return XEN_PLATFORM_ERR_PROTOCOL;
72 bool xen_has_pv_devices()
77 /* PV domains always have them. */
81 /* And user has xen_platform_pci=0 set in guest config as
82 * driver did not modify the value. */
83 if (xen_platform_pci_unplug == 0)
86 if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER)
89 if (xen_platform_pci_unplug & XEN_UNPLUG_ALL)
92 /* This is an odd one - we are going to run legacy
93 * and PV drivers at the same time. */
94 if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
97 /* And the caller has to follow with xen_pv_{disk,nic}_devices
98 * to be certain which driver can load. */
101 EXPORT_SYMBOL_GPL(xen_has_pv_devices);
103 static bool __xen_has_pv_device(int state)
105 /* HVM domains might or might not */
106 if (xen_hvm_domain() && (xen_platform_pci_unplug & state))
109 return xen_has_pv_devices();
112 bool xen_has_pv_nic_devices(void)
114 return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL);
116 EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices);
118 bool xen_has_pv_disk_devices(void)
120 return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS |
121 XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL);
123 EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices);
126 * This one is odd - it determines whether you want to run PV _and_
127 * legacy (IDE) drivers together. This combination is only possible
130 bool xen_has_pv_and_legacy_disk_devices(void)
135 /* N.B. This is only ever used in HVM mode */
139 if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
144 EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices);
146 void xen_unplug_emulated_devices(void)
150 /* user explicitly requested no unplug */
151 if (xen_emul_unplug & XEN_UNPLUG_NEVER)
153 /* check the version of the xen platform PCI device */
154 r = check_platform_magic();
155 /* If the version matches enable the Xen platform PCI driver.
156 * Also enable the Xen platform PCI driver if the host does
157 * not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC)
158 * but the user told us that unplugging is unnecessary. */
159 if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
160 (xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)))
162 /* Set the default value of xen_emul_unplug depending on whether or
163 * not the Xen PV frontends and the Xen platform PCI driver have
164 * been compiled for this kernel (modules or built-in are both OK). */
165 if (!xen_emul_unplug) {
166 if (xen_must_unplug_nics()) {
167 printk(KERN_INFO "Netfront and the Xen platform PCI driver have "
168 "been compiled for this kernel: unplug emulated NICs.\n");
169 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
171 if (xen_must_unplug_disks()) {
172 printk(KERN_INFO "Blkfront and the Xen platform PCI driver have "
173 "been compiled for this kernel: unplug emulated disks.\n"
174 "You might have to change the root device\n"
175 "from /dev/hd[a-d] to /dev/xvd[a-d]\n"
176 "in your root= kernel command line option\n");
177 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
180 /* Now unplug the emulated devices */
181 if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))
182 outw(xen_emul_unplug, XEN_IOPORT_UNPLUG);
183 xen_platform_pci_unplug = xen_emul_unplug;
186 static int __init parse_xen_emul_unplug(char *arg)
191 for (p = arg; p; p = q) {
199 if (!strncmp(p, "all", l))
200 xen_emul_unplug |= XEN_UNPLUG_ALL;
201 else if (!strncmp(p, "ide-disks", l))
202 xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
203 else if (!strncmp(p, "aux-ide-disks", l))
204 xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS;
205 else if (!strncmp(p, "nics", l))
206 xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
207 else if (!strncmp(p, "unnecessary", l))
208 xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY;
209 else if (!strncmp(p, "never", l))
210 xen_emul_unplug |= XEN_UNPLUG_NEVER;
212 printk(KERN_WARNING "unrecognised option '%s' "
213 "in parameter 'xen_emul_unplug'\n", p);
217 early_param("xen_emul_unplug", parse_xen_emul_unplug);