[mirror_ubuntu-artful-kernel.git] / arch / x86 / xen / platform-pci-unplug.c

/******************************************************************************
 * 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/export.h>

#include <xen/platform_pci.h>
#include "xen-ops.h"

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

#ifdef CONFIG_XEN_PVHVM
/* store the value of xen_emul_unplug after the unplug is done */
static int xen_platform_pci_unplug;
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\n");
		return XEN_PLATFORM_ERR_PROTOCOL;
	}

	return 0;
}

bool xen_has_pv_devices(void)
{
	if (!xen_domain())
		return false;

	/* PV and PVH domains always have them. */
	if (xen_pv_domain() || xen_pvh_domain())
		return true;

	/* And user has xen_platform_pci=0 set in guest config as
	 * driver did not modify the value. */
	if (xen_platform_pci_unplug == 0)
		return false;

	if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER)
		return false;

	if (xen_platform_pci_unplug & XEN_UNPLUG_ALL)
		return true;

	/* This is an odd one - we are going to run legacy
	 * and PV drivers at the same time. */
	if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
		return true;

	/* And the caller has to follow with xen_pv_{disk,nic}_devices
	 * to be certain which driver can load. */
	return false;
}
EXPORT_SYMBOL_GPL(xen_has_pv_devices);

static bool __xen_has_pv_device(int state)
{
	/* HVM domains might or might not */
	if (xen_hvm_domain() && (xen_platform_pci_unplug & state))
		return true;

	return xen_has_pv_devices();
}

bool xen_has_pv_nic_devices(void)
{
	return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS | XEN_UNPLUG_ALL);
}
EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices);

bool xen_has_pv_disk_devices(void)
{
	return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS |
				   XEN_UNPLUG_AUX_IDE_DISKS | XEN_UNPLUG_ALL);
}
EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices);

/*
 * This one is odd - it determines whether you want to run PV _and_
 * legacy (IDE) drivers together. This combination is only possible
 * under HVM.
 */
bool xen_has_pv_and_legacy_disk_devices(void)
{
	if (!xen_domain())
		return false;

	/* N.B. This is only ever used in HVM mode */
	if (xen_pv_domain())
		return false;

	if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
		return true;

	return false;
}
EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices);

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
Commit	Line	Data
c1c5413a SS	1	/******************************************************************************
	2	* platform-pci-unplug.c
	3	*
	4	* Xen platform PCI device driver
	5	* Copyright (c) 2010, Citrix
	6	*
	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.
	10	*
	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
	14	* more details.
	15	*
	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.
	19	*
	20	*/
	21
	22	#include <linux/init.h>
	23	#include <linux/io.h>
7a2463dc	24	#include <linux/export.h>
c1c5413a SS	25
c1c5413a SS	26	#include <xen/platform_pci.h>
b8b0f559	27	#include "xen-ops.h"
c1c5413a SS	28
	29	#define XEN_PLATFORM_ERR_MAGIC -1
	30	#define XEN_PLATFORM_ERR_PROTOCOL -2
	31	#define XEN_PLATFORM_ERR_BLACKLIST -3
	32
ca65f9fc	33	#ifdef CONFIG_XEN_PVHVM
6f6c15ef KRW	34	/* store the value of xen_emul_unplug after the unplug is done */
6f6c15ef KRW	35	static int xen_platform_pci_unplug;
c1c5413a SS	36	static int xen_emul_unplug;
c1c5413a SS	37
3c52b7bf	38	static int check_platform_magic(void)
c1c5413a SS	39	{
	40	short magic;
	41	char protocol;
	42
	43	magic = inw(XEN_IOPORT_MAGIC);
	44	if (magic != XEN_IOPORT_MAGIC_VAL) {
	45	printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n");
	46	return XEN_PLATFORM_ERR_MAGIC;
	47	}
	48
	49	protocol = inb(XEN_IOPORT_PROTOVER);
	50
	51	printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n",
	52	protocol);
	53
	54	switch (protocol) {
	55	case 1:
	56	outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM);
	57	outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER);
	58	if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) {
	59	printk(KERN_ERR "Xen Platform: blacklisted by host\n");
	60	return XEN_PLATFORM_ERR_BLACKLIST;
	61	}
	62	break;
	63	default:
8129554c	64	printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version\n");
c1c5413a SS	65	return XEN_PLATFORM_ERR_PROTOCOL;
	66	}
	67
	68	return 0;
	69	}
	70
772f95e3	71	bool xen_has_pv_devices(void)
51c71a3b KRW	72	{
	73	if (!xen_domain())
	74	return false;
	75
bcc57df2 BO	76	/* PV and PVH domains always have them. */
bcc57df2 BO	77	if (xen_pv_domain() \|\| xen_pvh_domain())
51c71a3b KRW	78	return true;
	79
	80	/* And user has xen_platform_pci=0 set in guest config as
	81	* driver did not modify the value. */
	82	if (xen_platform_pci_unplug == 0)
	83	return false;
	84
	85	if (xen_platform_pci_unplug & XEN_UNPLUG_NEVER)
	86	return false;
	87
	88	if (xen_platform_pci_unplug & XEN_UNPLUG_ALL)
	89	return true;
	90
	91	/* This is an odd one - we are going to run legacy
	92	* and PV drivers at the same time. */
	93	if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
	94	return true;
	95
	96	/* And the caller has to follow with xen_pv_{disk,nic}_devices
	97	* to be certain which driver can load. */
	98	return false;
	99	}
	100	EXPORT_SYMBOL_GPL(xen_has_pv_devices);
	101
	102	static bool __xen_has_pv_device(int state)
	103	{
	104	/* HVM domains might or might not */
	105	if (xen_hvm_domain() && (xen_platform_pci_unplug & state))
	106	return true;
	107
	108	return xen_has_pv_devices();
	109	}
	110
	111	bool xen_has_pv_nic_devices(void)
	112	{
	113	return __xen_has_pv_device(XEN_UNPLUG_ALL_NICS \| XEN_UNPLUG_ALL);
	114	}
	115	EXPORT_SYMBOL_GPL(xen_has_pv_nic_devices);
	116
	117	bool xen_has_pv_disk_devices(void)
	118	{
	119	return __xen_has_pv_device(XEN_UNPLUG_ALL_IDE_DISKS \|
	120	XEN_UNPLUG_AUX_IDE_DISKS \| XEN_UNPLUG_ALL);
	121	}
	122	EXPORT_SYMBOL_GPL(xen_has_pv_disk_devices);
	123
	124	/*
	125	* This one is odd - it determines whether you want to run PV _and_
	126	* legacy (IDE) drivers together. This combination is only possible
	127	* under HVM.
	128	*/
	129	bool xen_has_pv_and_legacy_disk_devices(void)
	130	{
	131	if (!xen_domain())
	132	return false;
	133
	134	/* N.B. This is only ever used in HVM mode */
	135	if (xen_pv_domain())
	136	return false;
	137
	138	if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY)
	139	return true;
	140
	141	return false;
142	}
143	EXPORT_SYMBOL_GPL(xen_has_pv_and_legacy_disk_devices);
144
512b109e	145	void xen_unplug_emulated_devices(void)
c1c5413a SS	146	{
	147	int r;
	148
c93a4dfb IC	149	/* user explicitly requested no unplug */
	150	if (xen_emul_unplug & XEN_UNPLUG_NEVER)
	151	return;
c1c5413a SS	152	/* check the version of the xen platform PCI device */
	153	r = check_platform_magic();
	154	/* If the version matches enable the Xen platform PCI driver.
1dc7ce99 IC	155	* Also enable the Xen platform PCI driver if the host does
	156	* not support the unplug protocol (XEN_PLATFORM_ERR_MAGIC)
	157	* but the user told us that unplugging is unnecessary. */
c1c5413a	158	if (r && !(r == XEN_PLATFORM_ERR_MAGIC &&
1dc7ce99	159	(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY)))
c1c5413a SS	160	return;
	161	/* Set the default value of xen_emul_unplug depending on whether or
	162	* not the Xen PV frontends and the Xen platform PCI driver have
	163	* been compiled for this kernel (modules or built-in are both OK). */
	164	if (!xen_emul_unplug) {
	165	if (xen_must_unplug_nics()) {
	166	printk(KERN_INFO "Netfront and the Xen platform PCI driver have "
	167	"been compiled for this kernel: unplug emulated NICs.\n");
	168	xen_emul_unplug \|= XEN_UNPLUG_ALL_NICS;
	169	}
	170	if (xen_must_unplug_disks()) {
	171	printk(KERN_INFO "Blkfront and the Xen platform PCI driver have "
	172	"been compiled for this kernel: unplug emulated disks.\n"
	173	"You might have to change the root device\n"
	174	"from /dev/hd[a-d] to /dev/xvd[a-d]\n"
	175	"in your root= kernel command line option\n");
	176	xen_emul_unplug \|= XEN_UNPLUG_ALL_IDE_DISKS;
	177	}
	178	}
	179	/* Now unplug the emulated devices */
1dc7ce99	180	if (!(xen_emul_unplug & XEN_UNPLUG_UNNECESSARY))
c1c5413a SS	181	outw(xen_emul_unplug, XEN_IOPORT_UNPLUG);
	182	xen_platform_pci_unplug = xen_emul_unplug;
	183	}
	184
	185	static int __init parse_xen_emul_unplug(char *arg)
	186	{
	187	char p, q;
	188	int l;
	189
	190	for (p = arg; p; p = q) {
	191	q = strchr(p, ',');
	192	if (q) {
	193	l = q - p;
	194	q++;
	195	} else {
	196	l = strlen(p);
	197	}
	198	if (!strncmp(p, "all", l))
	199	xen_emul_unplug \|= XEN_UNPLUG_ALL;
	200	else if (!strncmp(p, "ide-disks", l))
	201	xen_emul_unplug \|= XEN_UNPLUG_ALL_IDE_DISKS;
	202	else if (!strncmp(p, "aux-ide-disks", l))
	203	xen_emul_unplug \|= XEN_UNPLUG_AUX_IDE_DISKS;
	204	else if (!strncmp(p, "nics", l))
	205	xen_emul_unplug \|= XEN_UNPLUG_ALL_NICS;
1dc7ce99 IC	206	else if (!strncmp(p, "unnecessary", l))
1dc7ce99 IC	207	xen_emul_unplug \|= XEN_UNPLUG_UNNECESSARY;
c93a4dfb IC	208	else if (!strncmp(p, "never", l))
c93a4dfb IC	209	xen_emul_unplug \|= XEN_UNPLUG_NEVER;
c1c5413a SS	210	else
	211	printk(KERN_WARNING "unrecognised option '%s' "
	212	"in parameter 'xen_emul_unplug'\n", p);
	213	}
	214	return 0;
	215	}
	216	early_param("xen_emul_unplug", parse_xen_emul_unplug);
ca65f9fc	217	#endif