[deliverable/linux.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
#define DRV_NAME	"xen-pciback"

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, *tmp;
		list_for_each_entry_safe(e, tmp, &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;
}

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
a92336a1	15	#define DRV_NAME "xen-pciback"
30edc14b KRW	16
	17	struct vpci_dev_data {
	18	/* Access to dev_list must be protected by lock */
	19	struct list_head dev_list[PCI_SLOT_MAX];
	20	spinlock_t lock;
	21	};
	22
	23	static inline struct list_head list_first(struct list_head head)
	24	{
	25	return head->next;
	26	}
	27
2ebdc426 KRW	28	static struct pci_dev __xen_pcibk_get_pci_dev(struct xen_pcibk_device pdev,
	29	unsigned int domain,
	30	unsigned int bus,
	31	unsigned int devfn)
30edc14b KRW	32	{
	33	struct pci_dev_entry *entry;
	34	struct pci_dev *dev = NULL;
	35	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	36	unsigned long flags;
	37
	38	if (domain != 0 \|\| bus != 0)
	39	return NULL;
	40
	41	if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
	42	spin_lock_irqsave(&vpci_dev->lock, flags);
	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
	53	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	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;
	74	unsigned long flags;
	75
	76	if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
	77	err = -EFAULT;
	78	xenbus_dev_fatal(pdev->xdev, err,
	79	"Can't export bridges on the virtual PCI bus");
	80	goto out;
	81	}
	82
	83	dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
	84	if (!dev_entry) {
	85	err = -ENOMEM;
	86	xenbus_dev_fatal(pdev->xdev, err,
	87	"Error adding entry to virtual PCI bus");
	88	goto out;
	89	}
	90
	91	dev_entry->dev = dev;
	92
	93	spin_lock_irqsave(&vpci_dev->lock, flags);
	94
	95	/* Keep multi-function devices together on the virtual PCI bus */
	96	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	97	if (!list_empty(&vpci_dev->dev_list[slot])) {
	98	t = list_entry(list_first(&vpci_dev->dev_list[slot]),
	99	struct pci_dev_entry, list);
	100
	101	if (match_slot(dev, t->dev)) {
a92336a1	102	pr_info(DRV_NAME ": vpci: %s: "
30edc14b KRW	103	"assign to virtual slot %d func %d\n",
	104	pci_name(dev), slot,
	105	PCI_FUNC(dev->devfn));
	106	list_add_tail(&dev_entry->list,
	107	&vpci_dev->dev_list[slot]);
	108	func = PCI_FUNC(dev->devfn);
	109	goto unlock;
	110	}
	111	}
	112	}
	113
	114	/* Assign to a new slot on the virtual PCI bus */
	115	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	116	if (list_empty(&vpci_dev->dev_list[slot])) {
a92336a1 KRW	117	printk(KERN_INFO DRV_NAME
a92336a1 KRW	118	": vpci: %s: assign to virtual slot %d\n",
30edc14b KRW	119	pci_name(dev), slot);
	120	list_add_tail(&dev_entry->list,
	121	&vpci_dev->dev_list[slot]);
	122	func = PCI_FUNC(dev->devfn);
	123	goto unlock;
	124	}
	125	}
	126
	127	err = -ENOMEM;
	128	xenbus_dev_fatal(pdev->xdev, err,
	129	"No more space on root virtual PCI bus");
	130
	131	unlock:
	132	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	133
	134	/* Publish this device. */
	135	if (!err)
	136	err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
	137
	138	out:
	139	return err;
	140	}
	141
2ebdc426 KRW	142	static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
2ebdc426 KRW	143	struct pci_dev *dev)
30edc14b KRW	144	{
	145	int slot;
	146	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	147	struct pci_dev *found_dev = NULL;
	148	unsigned long flags;
	149
	150	spin_lock_irqsave(&vpci_dev->lock, flags);
	151
	152	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	153	struct pci_dev_entry e, tmp;
	154	list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
	155	list) {
	156	if (e->dev == dev) {
	157	list_del(&e->list);
	158	found_dev = e->dev;
	159	kfree(e);
	160	goto out;
	161	}
	162	}
	163	}
	164
	165	out:
	166	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	167
	168	if (found_dev)
	169	pcistub_put_pci_dev(found_dev);
	170	}
	171
2ebdc426	172	static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
30edc14b KRW	173	{
	174	int slot;
	175	struct vpci_dev_data *vpci_dev;
	176
	177	vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
	178	if (!vpci_dev)
	179	return -ENOMEM;
	180
	181	spin_lock_init(&vpci_dev->lock);
	182
	183	for (slot = 0; slot < PCI_SLOT_MAX; slot++)
	184	INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
	185
	186	pdev->pci_dev_data = vpci_dev;
	187
	188	return 0;
	189	}
	190
2ebdc426 KRW	191	static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
2ebdc426 KRW	192	publish_pci_root_cb publish_cb)
30edc14b KRW	193	{
	194	/* The Virtual PCI bus has only one root */
	195	return publish_cb(pdev, 0, 0);
	196	}
	197
2ebdc426	198	static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
30edc14b KRW	199	{
	200	int slot;
	201	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	202
	203	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	204	struct pci_dev_entry e, tmp;
	205	list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
	206	list) {
	207	list_del(&e->list);
	208	pcistub_put_pci_dev(e->dev);
	209	kfree(e);
	210	}
	211	}
	212
	213	kfree(vpci_dev);
	214	pdev->pci_dev_data = NULL;
	215	}
	216
2ebdc426 KRW	217	static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
	218	struct xen_pcibk_device *pdev,
	219	unsigned int domain, unsigned int bus,
	220	unsigned int *devfn)
30edc14b KRW	221	{
	222	struct pci_dev_entry *entry;
	223	struct pci_dev *dev = NULL;
	224	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
	225	unsigned long flags;
	226	int found = 0, slot;
	227
	228	spin_lock_irqsave(&vpci_dev->lock, flags);
	229	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
	230	list_for_each_entry(entry,
	231	&vpci_dev->dev_list[slot],
	232	list) {
	233	dev = entry->dev;
	234	if (dev && dev->bus->number == pcidev->bus->number
	235	&& pci_domain_nr(dev->bus) ==
	236	pci_domain_nr(pcidev->bus)
	237	&& dev->devfn == pcidev->devfn) {
	238	found = 1;
	239	*domain = 0;
	240	*bus = 0;
	241	*devfn = PCI_DEVFN(slot,
	242	PCI_FUNC(pcidev->devfn));
	243	}
	244	}
	245	}
	246	spin_unlock_irqrestore(&vpci_dev->lock, flags);
	247	return found;
	248	}
2ebdc426 KRW	249
	250	struct xen_pcibk_backend xen_pcibk_vpci_backend = {
	251	.name = "vpci",
	252	.init = __xen_pcibk_init_devices,
	253	.free = __xen_pcibk_release_devices,
	254	.find = __xen_pcibk_get_pcifront_dev,
	255	.publish = __xen_pcibk_publish_pci_roots,
	256	.release = __xen_pcibk_release_pci_dev,
	257	.add = __xen_pcibk_add_pci_dev,
	258	.get = __xen_pcibk_get_pci_dev,
	259	};