[mirror_ubuntu-zesty-kernel.git] / drivers / virtio / virtio_pci.c

/*
 * Virtio PCI driver
 *
 * This module allows virtio devices to be used over a virtual PCI device.
 * This can be used with QEMU based VMMs like KVM or Xen.
 *
 * Copyright IBM Corp. 2007
 *
 * Authors:
 *  Anthony Liguori  <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#include <linux/module.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_pci.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>

MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
MODULE_DESCRIPTION("virtio-pci");
MODULE_LICENSE("GPL");
MODULE_VERSION("1");

/* Our device structure */
struct virtio_pci_device
{
	struct virtio_device vdev;
	struct pci_dev *pci_dev;

	/* the IO mapping for the PCI config space */
	void __iomem *ioaddr;

	/* a list of queues so we can dispatch IRQs */
	spinlock_t lock;
	struct list_head virtqueues;
};

struct virtio_pci_vq_info
{
	/* the actual virtqueue */
	struct virtqueue *vq;

	/* the number of entries in the queue */
	int num;

	/* the index of the queue */
	int queue_index;

	/* the virtual address of the ring queue */
	void *queue;

	/* the list node for the virtqueues list */
	struct list_head node;
};

/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
static struct pci_device_id virtio_pci_id_table[] = {
	{ 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
	{ 0 },
};

MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);

/* A PCI device has it's own struct device and so does a virtio device so
 * we create a place for the virtio devices to show up in sysfs.  I think it
 * would make more sense for virtio to not insist on having it's own device. */
static struct device virtio_pci_root = {
	.parent		= NULL,
	.bus_id		= "virtio-pci",
};

/* Convert a generic virtio device to our structure */
static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
{
	return container_of(vdev, struct virtio_pci_device, vdev);
}

/* virtio config->get_features() implementation */
static u32 vp_get_features(struct virtio_device *vdev)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	/* When someone needs more than 32 feature bits, we'll need to
	 * steal a bit to indicate that the rest are somewhere else. */
	return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
}

/* virtio config->finalize_features() implementation */
static void vp_finalize_features(struct virtio_device *vdev)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	/* We only support 32 feature bits. */
	BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
	iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
}

/* virtio config->get() implementation */
static void vp_get(struct virtio_device *vdev, unsigned offset,
		   void *buf, unsigned len)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
	u8 *ptr = buf;
	int i;

	for (i = 0; i < len; i++)
		ptr[i] = ioread8(ioaddr + i);
}

/* the config->set() implementation.  it's symmetric to the config->get()
 * implementation */
static void vp_set(struct virtio_device *vdev, unsigned offset,
		   const void *buf, unsigned len)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
	const u8 *ptr = buf;
	int i;

	for (i = 0; i < len; i++)
		iowrite8(ptr[i], ioaddr + i);
}

/* config->{get,set}_status() implementations */
static u8 vp_get_status(struct virtio_device *vdev)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}

static void vp_set_status(struct virtio_device *vdev, u8 status)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	/* We should never be setting status to 0. */
	BUG_ON(status == 0);
	iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}

static void vp_reset(struct virtio_device *vdev)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	/* 0 status means a reset. */
	iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
}

/* the notify function used when creating a virt queue */
static void vp_notify(struct virtqueue *vq)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
	struct virtio_pci_vq_info *info = vq->priv;

	/* we write the queue's selector into the notification register to
	 * signal the other end */
	iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
}

/* A small wrapper to also acknowledge the interrupt when it's handled.
 * I really need an EIO hook for the vring so I can ack the interrupt once we
 * know that we'll be handling the IRQ but before we invoke the callback since
 * the callback may notify the host which results in the host attempting to
 * raise an interrupt that we would then mask once we acknowledged the
 * interrupt. */
static irqreturn_t vp_interrupt(int irq, void *opaque)
{
	struct virtio_pci_device *vp_dev = opaque;
	struct virtio_pci_vq_info *info;
	irqreturn_t ret = IRQ_NONE;
	unsigned long flags;
	u8 isr;

	/* reading the ISR has the effect of also clearing it so it's very
	 * important to save off the value. */
	isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);

	/* It's definitely not us if the ISR was not high */
	if (!isr)
		return IRQ_NONE;

	/* Configuration change?  Tell driver if it wants to know. */
	if (isr & VIRTIO_PCI_ISR_CONFIG) {
		struct virtio_driver *drv;
		drv = container_of(vp_dev->vdev.dev.driver,
				   struct virtio_driver, driver);

		if (drv->config_changed)
			drv->config_changed(&vp_dev->vdev);
	}

	spin_lock_irqsave(&vp_dev->lock, flags);
	list_for_each_entry(info, &vp_dev->virtqueues, node) {
		if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
			ret = IRQ_HANDLED;
	}
	spin_unlock_irqrestore(&vp_dev->lock, flags);

	return ret;
}

/* the config->find_vq() implementation */
static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
				    void (*callback)(struct virtqueue *vq))
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	struct virtio_pci_vq_info *info;
	struct virtqueue *vq;
	unsigned long flags;
	u16 num;
	int err;

	/* Select the queue we're interested in */
	iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);

	/* Check if queue is either not available or already active. */
	num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
	if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
		return ERR_PTR(-ENOENT);

	/* allocate and fill out our structure the represents an active
	 * queue */
	info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
	if (!info)
		return ERR_PTR(-ENOMEM);

	info->queue_index = index;
	info->num = num;

	info->queue = kzalloc(PAGE_ALIGN(vring_size(num,PAGE_SIZE)), GFP_KERNEL);
	if (info->queue == NULL) {
		err = -ENOMEM;
		goto out_info;
	}

	/* activate the queue */
	iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT,
		  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);

	/* create the vring */
	vq = vring_new_virtqueue(info->num, vdev, info->queue,
				 vp_notify, callback);
	if (!vq) {
		err = -ENOMEM;
		goto out_activate_queue;
	}

	vq->priv = info;
	info->vq = vq;

	spin_lock_irqsave(&vp_dev->lock, flags);
	list_add(&info->node, &vp_dev->virtqueues);
	spin_unlock_irqrestore(&vp_dev->lock, flags);

	return vq;

out_activate_queue:
	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
	kfree(info->queue);
out_info:
	kfree(info);
	return ERR_PTR(err);
}

/* the config->del_vq() implementation */
static void vp_del_vq(struct virtqueue *vq)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
	struct virtio_pci_vq_info *info = vq->priv;
	unsigned long flags;

	spin_lock_irqsave(&vp_dev->lock, flags);
	list_del(&info->node);
	spin_unlock_irqrestore(&vp_dev->lock, flags);

	vring_del_virtqueue(vq);

	/* Select and deactivate the queue */
	iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);

	kfree(info->queue);
	kfree(info);
}

static struct virtio_config_ops virtio_pci_config_ops = {
	.get		= vp_get,
	.set		= vp_set,
	.get_status	= vp_get_status,
	.set_status	= vp_set_status,
	.reset		= vp_reset,
	.find_vq	= vp_find_vq,
	.del_vq		= vp_del_vq,
	.get_features	= vp_get_features,
	.finalize_features = vp_finalize_features,
};

/* the PCI probing function */
static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
				      const struct pci_device_id *id)
{
	struct virtio_pci_device *vp_dev;
	int err;

	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
	if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
		return -ENODEV;

	if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
		printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
		       VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
		return -ENODEV;
	}

	/* allocate our structure and fill it out */
	vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
	if (vp_dev == NULL)
		return -ENOMEM;

	vp_dev->vdev.dev.parent = &virtio_pci_root;
	vp_dev->vdev.config = &virtio_pci_config_ops;
	vp_dev->pci_dev = pci_dev;
	INIT_LIST_HEAD(&vp_dev->virtqueues);
	spin_lock_init(&vp_dev->lock);

	/* enable the device */
	err = pci_enable_device(pci_dev);
	if (err)
		goto out;

	err = pci_request_regions(pci_dev, "virtio-pci");
	if (err)
		goto out_enable_device;

	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
	if (vp_dev->ioaddr == NULL)
		goto out_req_regions;

	pci_set_drvdata(pci_dev, vp_dev);

	/* we use the subsystem vendor/device id as the virtio vendor/device
	 * id.  this allows us to use the same PCI vendor/device id for all
	 * virtio devices and to identify the particular virtio driver by
	 * the subsytem ids */
	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
	vp_dev->vdev.id.device = pci_dev->subsystem_device;

	/* register a handler for the queue with the PCI device's interrupt */
	err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
			  vp_dev->vdev.dev.bus_id, vp_dev);
	if (err)
		goto out_set_drvdata;

	/* finally register the virtio device */
	err = register_virtio_device(&vp_dev->vdev);
	if (err)
		goto out_req_irq;

	return 0;

out_req_irq:
	free_irq(pci_dev->irq, vp_dev);
out_set_drvdata:
	pci_set_drvdata(pci_dev, NULL);
	pci_iounmap(pci_dev, vp_dev->ioaddr);
out_req_regions:
	pci_release_regions(pci_dev);
out_enable_device:
	pci_disable_device(pci_dev);
out:
	kfree(vp_dev);
	return err;
}

static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
{
	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);

	unregister_virtio_device(&vp_dev->vdev);
	free_irq(pci_dev->irq, vp_dev);
	pci_set_drvdata(pci_dev, NULL);
	pci_iounmap(pci_dev, vp_dev->ioaddr);
	pci_release_regions(pci_dev);
	pci_disable_device(pci_dev);
	kfree(vp_dev);
}

#ifdef CONFIG_PM
static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
{
	pci_save_state(pci_dev);
	pci_set_power_state(pci_dev, PCI_D3hot);
	return 0;
}

static int virtio_pci_resume(struct pci_dev *pci_dev)
{
	pci_restore_state(pci_dev);
	pci_set_power_state(pci_dev, PCI_D0);
	return 0;
}
#endif

static struct pci_driver virtio_pci_driver = {
	.name		= "virtio-pci",
	.id_table	= virtio_pci_id_table,
	.probe		= virtio_pci_probe,
	.remove		= virtio_pci_remove,
#ifdef CONFIG_PM
	.suspend	= virtio_pci_suspend,
	.resume		= virtio_pci_resume,
#endif
};

static int __init virtio_pci_init(void)
{
	int err;

	err = device_register(&virtio_pci_root);
	if (err)
		return err;

	err = pci_register_driver(&virtio_pci_driver);
	if (err)
		device_unregister(&virtio_pci_root);

	return err;
}

module_init(virtio_pci_init);

static void __exit virtio_pci_exit(void)
{
	device_unregister(&virtio_pci_root);
	pci_unregister_driver(&virtio_pci_driver);
}

module_exit(virtio_pci_exit);
Commit	Line	Data
3343660d AL	1	/*
	2	* Virtio PCI driver
	3	*
	4	* This module allows virtio devices to be used over a virtual PCI device.
	5	* This can be used with QEMU based VMMs like KVM or Xen.
	6	*
	7	* Copyright IBM Corp. 2007
	8	*
	9	* Authors:
	10	* Anthony Liguori <aliguori@us.ibm.com>
	11	*
	12	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	13	* See the COPYING file in the top-level directory.
	14	*
	15	*/
	16
	17	#include <linux/module.h>
	18	#include <linux/list.h>
	19	#include <linux/pci.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/virtio.h>
	22	#include <linux/virtio_config.h>
	23	#include <linux/virtio_ring.h>
	24	#include <linux/virtio_pci.h>
	25	#include <linux/highmem.h>
	26	#include <linux/spinlock.h>
	27
	28	MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
	29	MODULE_DESCRIPTION("virtio-pci");
	30	MODULE_LICENSE("GPL");
	31	MODULE_VERSION("1");
	32
	33	/* Our device structure */
	34	struct virtio_pci_device
	35	{
	36	struct virtio_device vdev;
	37	struct pci_dev *pci_dev;
	38
	39	/* the IO mapping for the PCI config space */
97968358	40	void __iomem *ioaddr;
3343660d AL	41
	42	/* a list of queues so we can dispatch IRQs */
	43	spinlock_t lock;
	44	struct list_head virtqueues;
	45	};
	46
	47	struct virtio_pci_vq_info
	48	{
	49	/* the actual virtqueue */
	50	struct virtqueue *vq;
	51
	52	/* the number of entries in the queue */
	53	int num;
	54
	55	/* the index of the queue */
	56	int queue_index;
	57
	58	/* the virtual address of the ring queue */
	59	void *queue;
	60
	61	/* the list node for the virtqueues list */
	62	struct list_head node;
	63	};
	64
	65	/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
	66	static struct pci_device_id virtio_pci_id_table[] = {
	67	{ 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
	68	{ 0 },
	69	};
	70
	71	MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
	72
	73	/* A PCI device has it's own struct device and so does a virtio device so
	74	* we create a place for the virtio devices to show up in sysfs. I think it
	75	* would make more sense for virtio to not insist on having it's own device. */
	76	static struct device virtio_pci_root = {
	77	.parent = NULL,
	78	.bus_id = "virtio-pci",
	79	};
	80
3343660d AL	81	/* Convert a generic virtio device to our structure */
	82	static struct virtio_pci_device to_vp_device(struct virtio_device vdev)
	83	{
	84	return container_of(vdev, struct virtio_pci_device, vdev);
	85	}
	86
c45a6816 RR	87	/* virtio config->get_features() implementation */
	88	static u32 vp_get_features(struct virtio_device *vdev)
	89	{
	90	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	91
	92	/* When someone needs more than 32 feature bits, we'll need to
	93	* steal a bit to indicate that the rest are somewhere else. */
	94	return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
	95	}
	96
c624896e RR	97	/* virtio config->finalize_features() implementation */
c624896e RR	98	static void vp_finalize_features(struct virtio_device *vdev)
3343660d AL	99	{
3343660d AL	100	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
3343660d	101
c624896e RR	102	/* We only support 32 feature bits. */
	103	BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
	104	iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
3343660d AL	105	}
	106
	107	/* virtio config->get() implementation */
	108	static void vp_get(struct virtio_device *vdev, unsigned offset,
	109	void *buf, unsigned len)
	110	{
	111	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
97968358	112	void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
3343660d AL	113	u8 *ptr = buf;
	114	int i;
	115
	116	for (i = 0; i < len; i++)
	117	ptr[i] = ioread8(ioaddr + i);
	118	}
	119
	120	/* the config->set() implementation. it's symmetric to the config->get()
	121	* implementation */
	122	static void vp_set(struct virtio_device *vdev, unsigned offset,
	123	const void *buf, unsigned len)
	124	{
	125	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
97968358	126	void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
3343660d AL	127	const u8 *ptr = buf;
	128	int i;
	129
	130	for (i = 0; i < len; i++)
	131	iowrite8(ptr[i], ioaddr + i);
	132	}
	133
	134	/* config->{get,set}_status() implementations */
	135	static u8 vp_get_status(struct virtio_device *vdev)
	136	{
	137	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	138	return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
	139	}
	140
	141	static void vp_set_status(struct virtio_device *vdev, u8 status)
	142	{
	143	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	144	/* We should never be setting status to 0. */
	145	BUG_ON(status == 0);
597d56e4	146	iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
3343660d AL	147	}
	148
	149	static void vp_reset(struct virtio_device *vdev)
	150	{
	151	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	152	/* 0 status means a reset. */
597d56e4	153	iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
3343660d AL	154	}
	155
	156	/* the notify function used when creating a virt queue */
	157	static void vp_notify(struct virtqueue *vq)
	158	{
	159	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
	160	struct virtio_pci_vq_info *info = vq->priv;
	161
	162	/* we write the queue's selector into the notification register to
	163	* signal the other end */
	164	iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
	165	}
	166
	167	/* A small wrapper to also acknowledge the interrupt when it's handled.
	168	* I really need an EIO hook for the vring so I can ack the interrupt once we
	169	* know that we'll be handling the IRQ but before we invoke the callback since
	170	* the callback may notify the host which results in the host attempting to
	171	* raise an interrupt that we would then mask once we acknowledged the
	172	* interrupt. */
	173	static irqreturn_t vp_interrupt(int irq, void *opaque)
	174	{
	175	struct virtio_pci_device *vp_dev = opaque;
	176	struct virtio_pci_vq_info *info;
	177	irqreturn_t ret = IRQ_NONE;
27ebe308	178	unsigned long flags;
3343660d AL	179	u8 isr;
	180
	181	/* reading the ISR has the effect of also clearing it so it's very
	182	* important to save off the value. */
	183	isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
	184
	185	/* It's definitely not us if the ISR was not high */
	186	if (!isr)
	187	return IRQ_NONE;
	188
	189	/* Configuration change? Tell driver if it wants to know. */
	190	if (isr & VIRTIO_PCI_ISR_CONFIG) {
	191	struct virtio_driver *drv;
	192	drv = container_of(vp_dev->vdev.dev.driver,
	193	struct virtio_driver, driver);
	194
	195	if (drv->config_changed)
	196	drv->config_changed(&vp_dev->vdev);
	197	}
	198
27ebe308	199	spin_lock_irqsave(&vp_dev->lock, flags);
3343660d AL	200	list_for_each_entry(info, &vp_dev->virtqueues, node) {
	201	if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
	202	ret = IRQ_HANDLED;
	203	}
27ebe308	204	spin_unlock_irqrestore(&vp_dev->lock, flags);
3343660d AL	205
	206	return ret;
	207	}
	208
	209	/* the config->find_vq() implementation */
	210	static struct virtqueue vp_find_vq(struct virtio_device vdev, unsigned index,
	211	void (callback)(struct virtqueue vq))
	212	{
	213	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	214	struct virtio_pci_vq_info *info;
	215	struct virtqueue *vq;
27ebe308	216	unsigned long flags;
3343660d AL	217	u16 num;
	218	int err;
	219
	220	/* Select the queue we're interested in */
	221	iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
	222
	223	/* Check if queue is either not available or already active. */
	224	num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
	225	if (!num \|\| ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
	226	return ERR_PTR(-ENOENT);
	227
	228	/* allocate and fill out our structure the represents an active
	229	* queue */
	230	info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
	231	if (!info)
	232	return ERR_PTR(-ENOMEM);
	233
	234	info->queue_index = index;
	235	info->num = num;
	236
	237	info->queue = kzalloc(PAGE_ALIGN(vring_size(num,PAGE_SIZE)), GFP_KERNEL);
	238	if (info->queue == NULL) {
	239	err = -ENOMEM;
	240	goto out_info;
	241	}
	242
	243	/* activate the queue */
	244	iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT,
	245	vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
	246
	247	/* create the vring */
	248	vq = vring_new_virtqueue(info->num, vdev, info->queue,
	249	vp_notify, callback);
	250	if (!vq) {
	251	err = -ENOMEM;
	252	goto out_activate_queue;
	253	}
	254
	255	vq->priv = info;
	256	info->vq = vq;
	257
27ebe308	258	spin_lock_irqsave(&vp_dev->lock, flags);
3343660d	259	list_add(&info->node, &vp_dev->virtqueues);
27ebe308	260	spin_unlock_irqrestore(&vp_dev->lock, flags);
3343660d AL	261
	262	return vq;
	263
	264	out_activate_queue:
	265	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
	266	kfree(info->queue);
	267	out_info:
	268	kfree(info);
	269	return ERR_PTR(err);
	270	}
	271
	272	/* the config->del_vq() implementation */
	273	static void vp_del_vq(struct virtqueue *vq)
	274	{
	275	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
	276	struct virtio_pci_vq_info *info = vq->priv;
27ebe308	277	unsigned long flags;
3343660d	278
27ebe308	279	spin_lock_irqsave(&vp_dev->lock, flags);
3343660d	280	list_del(&info->node);
27ebe308	281	spin_unlock_irqrestore(&vp_dev->lock, flags);
3343660d AL	282
	283	vring_del_virtqueue(vq);
	284
	285	/* Select and deactivate the queue */
	286	iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
	287	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
	288
	289	kfree(info->queue);
	290	kfree(info);
	291	}
	292
	293	static struct virtio_config_ops virtio_pci_config_ops = {
3343660d AL	294	.get = vp_get,
	295	.set = vp_set,
	296	.get_status = vp_get_status,
	297	.set_status = vp_set_status,
	298	.reset = vp_reset,
	299	.find_vq = vp_find_vq,
	300	.del_vq = vp_del_vq,
c45a6816	301	.get_features = vp_get_features,
c624896e	302	.finalize_features = vp_finalize_features,
3343660d AL	303	};
	304
	305	/* the PCI probing function */
	306	static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
	307	const struct pci_device_id *id)
	308	{
	309	struct virtio_pci_device *vp_dev;
	310	int err;
	311
	312	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
	313	if (pci_dev->device < 0x1000 \|\| pci_dev->device > 0x103f)
	314	return -ENODEV;
	315
55a7c066 AL	316	if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
	317	printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
	318	VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
	319	return -ENODEV;
	320	}
	321
3343660d AL	322	/* allocate our structure and fill it out */
	323	vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
	324	if (vp_dev == NULL)
	325	return -ENOMEM;
	326
3343660d AL	327	vp_dev->vdev.dev.parent = &virtio_pci_root;
	328	vp_dev->vdev.config = &virtio_pci_config_ops;
	329	vp_dev->pci_dev = pci_dev;
	330	INIT_LIST_HEAD(&vp_dev->virtqueues);
	331	spin_lock_init(&vp_dev->lock);
	332
	333	/* enable the device */
	334	err = pci_enable_device(pci_dev);
	335	if (err)
	336	goto out;
	337
	338	err = pci_request_regions(pci_dev, "virtio-pci");
	339	if (err)
	340	goto out_enable_device;
	341
	342	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
	343	if (vp_dev->ioaddr == NULL)
	344	goto out_req_regions;
	345
	346	pci_set_drvdata(pci_dev, vp_dev);
	347
	348	/* we use the subsystem vendor/device id as the virtio vendor/device
	349	* id. this allows us to use the same PCI vendor/device id for all
	350	* virtio devices and to identify the particular virtio driver by
	351	* the subsytem ids */
	352	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
	353	vp_dev->vdev.id.device = pci_dev->subsystem_device;
	354
	355	/* register a handler for the queue with the PCI device's interrupt */
	356	err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
	357	vp_dev->vdev.dev.bus_id, vp_dev);
	358	if (err)
	359	goto out_set_drvdata;
	360
	361	/* finally register the virtio device */
	362	err = register_virtio_device(&vp_dev->vdev);
	363	if (err)
	364	goto out_req_irq;
	365
	366	return 0;
	367
	368	out_req_irq:
	369	free_irq(pci_dev->irq, vp_dev);
	370	out_set_drvdata:
	371	pci_set_drvdata(pci_dev, NULL);
	372	pci_iounmap(pci_dev, vp_dev->ioaddr);
	373	out_req_regions:
	374	pci_release_regions(pci_dev);
	375	out_enable_device:
	376	pci_disable_device(pci_dev);
	377	out:
	378	kfree(vp_dev);
	379	return err;
	380	}
	381
	382	static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
	383	{
	384	struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
	385
bd6c2690	386	unregister_virtio_device(&vp_dev->vdev);
3343660d AL	387	free_irq(pci_dev->irq, vp_dev);
	388	pci_set_drvdata(pci_dev, NULL);
	389	pci_iounmap(pci_dev, vp_dev->ioaddr);
	390	pci_release_regions(pci_dev);
	391	pci_disable_device(pci_dev);
	392	kfree(vp_dev);
	393	}
	394
	395	#ifdef CONFIG_PM
	396	static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
	397	{
	398	pci_save_state(pci_dev);
	399	pci_set_power_state(pci_dev, PCI_D3hot);
	400	return 0;
	401	}
	402
	403	static int virtio_pci_resume(struct pci_dev *pci_dev)
	404	{
	405	pci_restore_state(pci_dev);
	406	pci_set_power_state(pci_dev, PCI_D0);
	407	return 0;
	408	}
	409	#endif
	410
	411	static struct pci_driver virtio_pci_driver = {
	412	.name = "virtio-pci",
	413	.id_table = virtio_pci_id_table,
	414	.probe = virtio_pci_probe,
	415	.remove = virtio_pci_remove,
	416	#ifdef CONFIG_PM
	417	.suspend = virtio_pci_suspend,
	418	.resume = virtio_pci_resume,
	419	#endif
	420	};
	421
	422	static int __init virtio_pci_init(void)
	423	{
	424	int err;
	425
	426	err = device_register(&virtio_pci_root);
	427	if (err)
	428	return err;
	429
	430	err = pci_register_driver(&virtio_pci_driver);
	431	if (err)
	432	device_unregister(&virtio_pci_root);
	433
	434	return err;
	435	}
	436
	437	module_init(virtio_pci_init);
	438
	439	static void __exit virtio_pci_exit(void)
	440	{
	441	device_unregister(&virtio_pci_root);
	442	pci_unregister_driver(&virtio_pci_driver);
	443	}
	444
	445	module_exit(virtio_pci_exit);