[linux-2.6-block.git] / drivers / xen / xen-pciback / vpci.c

/*
 * PCI Backend - Provides a Virtual PCI bus (with real devices)
 *               to the frontend
 *
 *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/list.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/mutex.h>
#include "pciback.h"

#define PCI_SLOT_MAX 32

struct vpci_dev_data {
	/* Access to dev_list must be protected by lock */
	struct list_head dev_list[PCI_SLOT_MAX];
	struct mutex lock;
};

static inline struct list_head *list_first(struct list_head *head)
{
	return head->next;
}

static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
					       unsigned int domain,
					       unsigned int bus,
					       unsigned int devfn)
{
	struct pci_dev_entry *entry;
	struct pci_dev *dev = NULL;
	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;

	if (domain != 0 || bus != 0)
		return NULL;

	if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
		mutex_lock(&vpci_dev->lock);

		list_for_each_entry(entry,
				    &vpci_dev->dev_list[PCI_SLOT(devfn)],
				    list) {
			if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
				dev = entry->dev;
				break;
			}
		}

		mutex_unlock(&vpci_dev->lock);
	}
	return dev;
}

static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
{
	if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
	    && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
		return 1;

	return 0;
}

static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
				   struct pci_dev *dev, int devid,
				   publish_pci_dev_cb publish_cb)
{
	int err = 0, slot, func = -1;
	struct pci_dev_entry *t, *dev_entry;
	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;

	if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
		err = -EFAULT;
		xenbus_dev_fatal(pdev->xdev, err,
				 "Can't export bridges on the virtual PCI bus");
		goto out;
	}

	dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
	if (!dev_entry) {
		err = -ENOMEM;
		xenbus_dev_fatal(pdev->xdev, err,
				 "Error adding entry to virtual PCI bus");
		goto out;
	}

	dev_entry->dev = dev;

	mutex_lock(&vpci_dev->lock);

	/*
	 * Keep multi-function devices together on the virtual PCI bus, except
	 * virtual functions.
	 */
	if (!dev->is_virtfn) {
		for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
			if (list_empty(&vpci_dev->dev_list[slot]))
				continue;

			t = list_entry(list_first(&vpci_dev->dev_list[slot]),
				       struct pci_dev_entry, list);

			if (match_slot(dev, t->dev)) {
				pr_info("vpci: %s: assign to virtual slot %d func %d\n",
					pci_name(dev), slot,
					PCI_FUNC(dev->devfn));
				list_add_tail(&dev_entry->list,
					      &vpci_dev->dev_list[slot]);
				func = PCI_FUNC(dev->devfn);
				goto unlock;
			}
		}
	}

	/* Assign to a new slot on the virtual PCI bus */
	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
		if (list_empty(&vpci_dev->dev_list[slot])) {
			pr_info("vpci: %s: assign to virtual slot %d\n",
				pci_name(dev), slot);
			list_add_tail(&dev_entry->list,
				      &vpci_dev->dev_list[slot]);
			func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
			goto unlock;
		}
	}

	err = -ENOMEM;
	xenbus_dev_fatal(pdev->xdev, err,
			 "No more space on root virtual PCI bus");

unlock:
	mutex_unlock(&vpci_dev->lock);

	/* Publish this device. */
	if (!err)
		err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
	else
		kfree(dev_entry);

out:
	return err;
}

static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
					struct pci_dev *dev, bool lock)
{
	int slot;
	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	struct pci_dev *found_dev = NULL;

	mutex_lock(&vpci_dev->lock);

	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
		struct pci_dev_entry *e;

		list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
			if (e->dev == dev) {
				list_del(&e->list);
				found_dev = e->dev;
				kfree(e);
				goto out;
			}
		}
	}

out:
	mutex_unlock(&vpci_dev->lock);

	if (found_dev) {
		if (lock)
			device_lock(&found_dev->dev);
		pcistub_put_pci_dev(found_dev);
		if (lock)
			device_unlock(&found_dev->dev);
	}
}

static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
{
	int slot;
	struct vpci_dev_data *vpci_dev;

	vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
	if (!vpci_dev)
		return -ENOMEM;

	mutex_init(&vpci_dev->lock);

	for (slot = 0; slot < PCI_SLOT_MAX; slot++)
		INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);

	pdev->pci_dev_data = vpci_dev;

	return 0;
}

static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
					 publish_pci_root_cb publish_cb)
{
	/* The Virtual PCI bus has only one root */
	return publish_cb(pdev, 0, 0);
}

static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
{
	int slot;
	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;

	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
		struct pci_dev_entry *e, *tmp;
		list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
					 list) {
			struct pci_dev *dev = e->dev;
			list_del(&e->list);
			device_lock(&dev->dev);
			pcistub_put_pci_dev(dev);
			device_unlock(&dev->dev);
			kfree(e);
		}
	}

	kfree(vpci_dev);
	pdev->pci_dev_data = NULL;
}

static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
					struct xen_pcibk_device *pdev,
					unsigned int *domain, unsigned int *bus,
					unsigned int *devfn)
{
	struct pci_dev_entry *entry;
	struct pci_dev *dev = NULL;
	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	int found = 0, slot;

	mutex_lock(&vpci_dev->lock);
	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
		list_for_each_entry(entry,
			    &vpci_dev->dev_list[slot],
			    list) {
			dev = entry->dev;
			if (dev && dev->bus->number == pcidev->bus->number
				&& pci_domain_nr(dev->bus) ==
					pci_domain_nr(pcidev->bus)
				&& dev->devfn == pcidev->devfn) {
				found = 1;
				*domain = 0;
				*bus = 0;
				*devfn = PCI_DEVFN(slot,
					 PCI_FUNC(pcidev->devfn));
			}
		}
	}
	mutex_unlock(&vpci_dev->lock);
	return found;
}

const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
	.name		= "vpci",
	.init		= __xen_pcibk_init_devices,
	.free		= __xen_pcibk_release_devices,
	.find		= __xen_pcibk_get_pcifront_dev,
	.publish	= __xen_pcibk_publish_pci_roots,
	.release	= __xen_pcibk_release_pci_dev,
	.add		= __xen_pcibk_add_pci_dev,
	.get		= __xen_pcibk_get_pci_dev,
};
Commit	Line	Data
30edc14b KRW	1	/*
	2	* PCI Backend - Provides a Virtual PCI bus (with real devices)
	3	* to the frontend
	4	*
	5	* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
	6	*/
	7
283c0972 JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
283c0972 JP	9
30edc14b KRW	10	#include <linux/list.h>
	11	#include <linux/slab.h>
	12	#include <linux/pci.h>
74d33ded	13	#include <linux/mutex.h>
30edc14b KRW	14	#include "pciback.h"
	15
	16	#define PCI_SLOT_MAX 32
	17
	18	struct vpci_dev_data {
	19	/* Access to dev_list must be protected by lock */
	20	struct list_head dev_list[PCI_SLOT_MAX];
74d33ded	21	struct mutex lock;
30edc14b KRW	22	};
	23
	24	static inline struct list_head list_first(struct list_head head)
	25	{
	26	return head->next;
	27	}
	28
2ebdc426 KRW	29	static struct pci_dev __xen_pcibk_get_pci_dev(struct xen_pcibk_device pdev,
	30	unsigned int domain,
	31	unsigned int bus,
	32	unsigned int devfn)
30edc14b KRW	33	{
	34	struct pci_dev_entry *entry;
	35	struct pci_dev *dev = NULL;
	36	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
30edc14b KRW	37
	38	if (domain != 0 \|\| bus != 0)
	39	return NULL;
	40
	41	if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
74d33ded	42	mutex_lock(&vpci_dev->lock);
30edc14b KRW	43
	44	list_for_each_entry(entry,
	45	&vpci_dev->dev_list[PCI_SLOT(devfn)],
	46	list) {
	47	if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
	48	dev = entry->dev;
	49	break;
	50	}
	51	}
	52
74d33ded	53	mutex_unlock(&vpci_dev->lock);
30edc14b KRW	54	}
	55	return dev;
	56	}
	57
	58	static inline int match_slot(struct pci_dev l, struct pci_dev r)
	59	{
	60	if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
	61	&& l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
	62	return 1;
	63
	64	return 0;
	65	}
	66
2ebdc426 KRW	67	static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
	68	struct pci_dev *dev, int devid,
	69	publish_pci_dev_cb publish_cb)
30edc14b KRW	70	{
	71	int err = 0, slot, func = -1;
	72	struct pci_dev_entry t, dev_entry;
	73	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
30edc14b KRW	74
	75	if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
	76	err = -EFAULT;
	77	xenbus_dev_fatal(pdev->xdev, err,
	78	"Can't export bridges on the virtual PCI bus");
	79	goto out;
	80	}
	81
	82	dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
	83	if (!dev_entry) {
	84	err = -ENOMEM;
	85	xenbus_dev_fatal(pdev->xdev, err,
	86	"Error adding entry to virtual PCI bus");
	87	goto out;
	88	}
	89
	90	dev_entry->dev = dev;
	91
74d33ded	92	mutex_lock(&vpci_dev->lock);
30edc14b	93
8a5248fe LE	94	/*
	95	* Keep multi-function devices together on the virtual PCI bus, except
	96	* virtual functions.
	97	*/
	98	if (!dev->is_virtfn) {
	99	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	100	if (list_empty(&vpci_dev->dev_list[slot]))
	101	continue;
	102
30edc14b KRW	103	t = list_entry(list_first(&vpci_dev->dev_list[slot]),
	104	struct pci_dev_entry, list);
	105
	106	if (match_slot(dev, t->dev)) {
283c0972	107	pr_info("vpci: %s: assign to virtual slot %d func %d\n",
30edc14b KRW	108	pci_name(dev), slot,
	109	PCI_FUNC(dev->devfn));
	110	list_add_tail(&dev_entry->list,
	111	&vpci_dev->dev_list[slot]);
	112	func = PCI_FUNC(dev->devfn);
	113	goto unlock;
	114	}
	115	}
	116	}
	117
	118	/* Assign to a new slot on the virtual PCI bus */
	119	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	120	if (list_empty(&vpci_dev->dev_list[slot])) {
283c0972 JP	121	pr_info("vpci: %s: assign to virtual slot %d\n",
283c0972 JP	122	pci_name(dev), slot);
30edc14b KRW	123	list_add_tail(&dev_entry->list,
30edc14b KRW	124	&vpci_dev->dev_list[slot]);
8a5248fe	125	func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
30edc14b KRW	126	goto unlock;
	127	}
	128	}
	129
	130	err = -ENOMEM;
	131	xenbus_dev_fatal(pdev->xdev, err,
	132	"No more space on root virtual PCI bus");
	133
	134	unlock:
74d33ded	135	mutex_unlock(&vpci_dev->lock);
30edc14b KRW	136
	137	/* Publish this device. */
	138	if (!err)
	139	err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
cea37f87 DY	140	else
cea37f87 DY	141	kfree(dev_entry);
30edc14b KRW	142
	143	out:
	144	return err;
	145	}
	146
2ebdc426	147	static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
e8801a74	148	struct pci_dev *dev, bool lock)
30edc14b KRW	149	{
	150	int slot;
	151	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	152	struct pci_dev *found_dev = NULL;
30edc14b	153
74d33ded	154	mutex_lock(&vpci_dev->lock);
30edc14b KRW	155
30edc14b KRW	156	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
402c5e15 JB	157	struct pci_dev_entry *e;
	158
	159	list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
30edc14b KRW	160	if (e->dev == dev) {
	161	list_del(&e->list);
	162	found_dev = e->dev;
	163	kfree(e);
	164	goto out;
	165	}
	166	}
	167	}
	168
	169	out:
74d33ded	170	mutex_unlock(&vpci_dev->lock);
30edc14b	171
e8801a74 KRW	172	if (found_dev) {
	173	if (lock)
	174	device_lock(&found_dev->dev);
30edc14b	175	pcistub_put_pci_dev(found_dev);
e8801a74 KRW	176	if (lock)
	177	device_unlock(&found_dev->dev);
	178	}
30edc14b KRW	179	}
30edc14b KRW	180
2ebdc426	181	static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
30edc14b KRW	182	{
	183	int slot;
	184	struct vpci_dev_data *vpci_dev;
	185
	186	vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
	187	if (!vpci_dev)
	188	return -ENOMEM;
	189
74d33ded	190	mutex_init(&vpci_dev->lock);
30edc14b KRW	191
	192	for (slot = 0; slot < PCI_SLOT_MAX; slot++)
	193	INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
	194
	195	pdev->pci_dev_data = vpci_dev;
	196
	197	return 0;
	198	}
	199
2ebdc426 KRW	200	static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
2ebdc426 KRW	201	publish_pci_root_cb publish_cb)
30edc14b KRW	202	{
	203	/* The Virtual PCI bus has only one root */
	204	return publish_cb(pdev, 0, 0);
	205	}
	206
2ebdc426	207	static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
30edc14b KRW	208	{
	209	int slot;
	210	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	211
	212	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	213	struct pci_dev_entry e, tmp;
	214	list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
	215	list) {
e8801a74	216	struct pci_dev *dev = e->dev;
30edc14b	217	list_del(&e->list);
e8801a74 KRW	218	device_lock(&dev->dev);
	219	pcistub_put_pci_dev(dev);
	220	device_unlock(&dev->dev);
30edc14b KRW	221	kfree(e);
	222	}
	223	}
	224
	225	kfree(vpci_dev);
	226	pdev->pci_dev_data = NULL;
	227	}
	228
2ebdc426 KRW	229	static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
	230	struct xen_pcibk_device *pdev,
	231	unsigned int domain, unsigned int bus,
	232	unsigned int *devfn)
30edc14b KRW	233	{
	234	struct pci_dev_entry *entry;
	235	struct pci_dev *dev = NULL;
	236	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
30edc14b KRW	237	int found = 0, slot;
30edc14b KRW	238
74d33ded	239	mutex_lock(&vpci_dev->lock);
30edc14b KRW	240	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	241	list_for_each_entry(entry,
	242	&vpci_dev->dev_list[slot],
	243	list) {
	244	dev = entry->dev;
	245	if (dev && dev->bus->number == pcidev->bus->number
	246	&& pci_domain_nr(dev->bus) ==
	247	pci_domain_nr(pcidev->bus)
	248	&& dev->devfn == pcidev->devfn) {
	249	found = 1;
	250	*domain = 0;
	251	*bus = 0;
	252	*devfn = PCI_DEVFN(slot,
	253	PCI_FUNC(pcidev->devfn));
	254	}
	255	}
	256	}
e1db4cef	257	mutex_unlock(&vpci_dev->lock);
30edc14b KRW	258	return found;
30edc14b KRW	259	}
2ebdc426	260
402c5e15	261	const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
2ebdc426 KRW	262	.name = "vpci",
	263	.init = __xen_pcibk_init_devices,
	264	.free = __xen_pcibk_release_devices,
	265	.find = __xen_pcibk_get_pcifront_dev,
	266	.publish = __xen_pcibk_publish_pci_roots,
	267	.release = __xen_pcibk_release_pci_dev,
	268	.add = __xen_pcibk_add_pci_dev,
	269	.get = __xen_pcibk_get_pci_dev,
	270	};