[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>
 */

#include <linux/list.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/spinlock.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];
	spinlock_t 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;
	unsigned long flags;

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

	if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
		spin_lock_irqsave(&vpci_dev->lock, flags);

		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;
			}
		}

		spin_unlock_irqrestore(&vpci_dev->lock, flags);
	}
	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;
	unsigned long flags;

	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;

	spin_lock_irqsave(&vpci_dev->lock, flags);

	/* Keep multi-function devices together on the virtual PCI bus */
	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
		if (!list_empty(&vpci_dev->dev_list[slot])) {
			t = list_entry(list_first(&vpci_dev->dev_list[slot]),
				       struct pci_dev_entry, list);

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

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

unlock:
	spin_unlock_irqrestore(&vpci_dev->lock, flags);

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

out:
	return err;
}

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

	spin_lock_irqsave(&vpci_dev->lock, flags);

	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:
	spin_unlock_irqrestore(&vpci_dev->lock, flags);

	if (found_dev)
		pcistub_put_pci_dev(found_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;

	spin_lock_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) {
			list_del(&e->list);
			pcistub_put_pci_dev(e->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;
	unsigned long flags;
	int found = 0, slot;

	spin_lock_irqsave(&vpci_dev->lock, flags);
	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));
			}
		}
	}
	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	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
	8	#include <linux/list.h>
	9	#include <linux/slab.h>
	10	#include <linux/pci.h>
	11	#include <linux/spinlock.h>
	12	#include "pciback.h"
	13
	14	#define PCI_SLOT_MAX 32
	15
	16	struct vpci_dev_data {
	17	/* Access to dev_list must be protected by lock */
	18	struct list_head dev_list[PCI_SLOT_MAX];
	19	spinlock_t lock;
	20	};
	21
	22	static inline struct list_head list_first(struct list_head head)
	23	{
	24	return head->next;
	25	}
	26
2ebdc426 KRW	27	static struct pci_dev __xen_pcibk_get_pci_dev(struct xen_pcibk_device pdev,
	28	unsigned int domain,
	29	unsigned int bus,
	30	unsigned int devfn)
30edc14b KRW	31	{
	32	struct pci_dev_entry *entry;
	33	struct pci_dev *dev = NULL;
	34	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	35	unsigned long flags;
	36
	37	if (domain != 0 \|\| bus != 0)
	38	return NULL;
	39
	40	if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
	41	spin_lock_irqsave(&vpci_dev->lock, flags);
	42
	43	list_for_each_entry(entry,
	44	&vpci_dev->dev_list[PCI_SLOT(devfn)],
	45	list) {
	46	if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
	47	dev = entry->dev;
	48	break;
	49	}
	50	}
	51
	52	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	53	}
	54	return dev;
	55	}
	56
	57	static inline int match_slot(struct pci_dev l, struct pci_dev r)
	58	{
	59	if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
	60	&& l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
	61	return 1;
	62
	63	return 0;
	64	}
	65
2ebdc426 KRW	66	static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
	67	struct pci_dev *dev, int devid,
	68	publish_pci_dev_cb publish_cb)
30edc14b KRW	69	{
	70	int err = 0, slot, func = -1;
	71	struct pci_dev_entry t, dev_entry;
	72	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	73	unsigned long flags;
	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
	92	spin_lock_irqsave(&vpci_dev->lock, flags);
	93
	94	/* Keep multi-function devices together on the virtual PCI bus */
	95	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	96	if (!list_empty(&vpci_dev->dev_list[slot])) {
	97	t = list_entry(list_first(&vpci_dev->dev_list[slot]),
	98	struct pci_dev_entry, list);
	99
	100	if (match_slot(dev, t->dev)) {
a92336a1	101	pr_info(DRV_NAME ": vpci: %s: "
30edc14b KRW	102	"assign to virtual slot %d func %d\n",
	103	pci_name(dev), slot,
	104	PCI_FUNC(dev->devfn));
	105	list_add_tail(&dev_entry->list,
	106	&vpci_dev->dev_list[slot]);
	107	func = PCI_FUNC(dev->devfn);
	108	goto unlock;
	109	}
	110	}
	111	}
	112
	113	/* Assign to a new slot on the virtual PCI bus */
	114	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	115	if (list_empty(&vpci_dev->dev_list[slot])) {
a92336a1 KRW	116	printk(KERN_INFO DRV_NAME
a92336a1 KRW	117	": vpci: %s: assign to virtual slot %d\n",
30edc14b KRW	118	pci_name(dev), slot);
	119	list_add_tail(&dev_entry->list,
	120	&vpci_dev->dev_list[slot]);
	121	func = PCI_FUNC(dev->devfn);
	122	goto unlock;
	123	}
	124	}
	125
	126	err = -ENOMEM;
	127	xenbus_dev_fatal(pdev->xdev, err,
	128	"No more space on root virtual PCI bus");
	129
	130	unlock:
	131	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	132
	133	/* Publish this device. */
	134	if (!err)
	135	err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
	136
	137	out:
	138	return err;
	139	}
	140
2ebdc426 KRW	141	static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
2ebdc426 KRW	142	struct pci_dev *dev)
30edc14b KRW	143	{
	144	int slot;
	145	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	146	struct pci_dev *found_dev = NULL;
	147	unsigned long flags;
	148
	149	spin_lock_irqsave(&vpci_dev->lock, flags);
	150
	151	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
402c5e15 JB	152	struct pci_dev_entry *e;
	153
	154	list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
30edc14b KRW	155	if (e->dev == dev) {
	156	list_del(&e->list);
	157	found_dev = e->dev;
	158	kfree(e);
	159	goto out;
	160	}
	161	}
	162	}
	163
	164	out:
	165	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	166
	167	if (found_dev)
	168	pcistub_put_pci_dev(found_dev);
	169	}
	170
2ebdc426	171	static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
30edc14b KRW	172	{
	173	int slot;
	174	struct vpci_dev_data *vpci_dev;
	175
	176	vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
	177	if (!vpci_dev)
	178	return -ENOMEM;
	179
	180	spin_lock_init(&vpci_dev->lock);
	181
	182	for (slot = 0; slot < PCI_SLOT_MAX; slot++)
	183	INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
	184
	185	pdev->pci_dev_data = vpci_dev;
	186
	187	return 0;
	188	}
	189
2ebdc426 KRW	190	static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
2ebdc426 KRW	191	publish_pci_root_cb publish_cb)
30edc14b KRW	192	{
	193	/* The Virtual PCI bus has only one root */
	194	return publish_cb(pdev, 0, 0);
	195	}
	196
2ebdc426	197	static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
30edc14b KRW	198	{
	199	int slot;
	200	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	201
	202	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	203	struct pci_dev_entry e, tmp;
	204	list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
	205	list) {
	206	list_del(&e->list);
	207	pcistub_put_pci_dev(e->dev);
	208	kfree(e);
	209	}
	210	}
	211
	212	kfree(vpci_dev);
	213	pdev->pci_dev_data = NULL;
	214	}
	215
2ebdc426 KRW	216	static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
	217	struct xen_pcibk_device *pdev,
	218	unsigned int domain, unsigned int bus,
	219	unsigned int *devfn)
30edc14b KRW	220	{
	221	struct pci_dev_entry *entry;
	222	struct pci_dev *dev = NULL;
	223	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	224	unsigned long flags;
	225	int found = 0, slot;
	226
	227	spin_lock_irqsave(&vpci_dev->lock, flags);
	228	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	229	list_for_each_entry(entry,
	230	&vpci_dev->dev_list[slot],
	231	list) {
	232	dev = entry->dev;
	233	if (dev && dev->bus->number == pcidev->bus->number
	234	&& pci_domain_nr(dev->bus) ==
	235	pci_domain_nr(pcidev->bus)
	236	&& dev->devfn == pcidev->devfn) {
	237	found = 1;
	238	*domain = 0;
	239	*bus = 0;
	240	*devfn = PCI_DEVFN(slot,
	241	PCI_FUNC(pcidev->devfn));
	242	}
	243	}
	244	}
	245	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	246	return found;
	247	}
2ebdc426	248
402c5e15	249	const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
2ebdc426 KRW	250	.name = "vpci",
	251	.init = __xen_pcibk_init_devices,
	252	.free = __xen_pcibk_release_devices,
	253	.find = __xen_pcibk_get_pcifront_dev,
	254	.publish = __xen_pcibk_publish_pci_roots,
	255	.release = __xen_pcibk_release_pci_dev,
	256	.add = __xen_pcibk_add_pci_dev,
	257	.get = __xen_pcibk_get_pci_dev,
	258	};