/******************************************************************************
* 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 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 xen_unplug_emulated_devices(void)
{
int r;
/* user explicitly requested no unplug */
if (xen_emul_unplug & XEN_UNPLUG_NEVER)
return;
/* 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 host does
* not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC)
* but the user told us that unplugging is unnecessary. */
if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)))
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_UNNECESSARY))
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, "unnecessary", l))
xen_emul_unplug |= XEN_UNPLUG_UNNECESSARY;
else if (!strncmp(p, "never", l))
xen_emul_unplug |= XEN_UNPLUG_NEVER;
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
