[linux-2.6-block.git] / drivers / virtio / virtio_pci_legacy.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Virtio PCI driver - legacy device support
 *
 * 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
 * Copyright Red Hat, Inc. 2014
 *
 * Authors:
 *  Anthony Liguori  <aliguori@us.ibm.com>
 *  Rusty Russell <rusty@rustcorp.com.au>
 *  Michael S. Tsirkin <mst@redhat.com>
 */

#include "virtio_pci_common.h"

/* virtio config->get_features() implementation */
static u64 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 int vp_finalize_features(struct virtio_device *vdev)
{
	struct virtio_pci_device *vp_dev = to_vp_device(vdev);

	/* Give virtio_ring a chance to accept features. */
	vring_transport_features(vdev);

	/* Make sure we don't have any features > 32 bits! */
	BUG_ON((u32)vdev->features != vdev->features);

	/* We only support 32 feature bits. */
	iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);

	return 0;
}

/* 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_OFF(vp_dev->msix_enabled) +
			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_OFF(vp_dev->msix_enabled) +
			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);
	/* Flush out the status write, and flush in device writes,
	 * including MSi-X interrupts, if any. */
	ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
	/* Flush pending VQ/configuration callbacks. */
	vp_synchronize_vectors(vdev);
}

static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
{
	/* Setup the vector used for configuration events */
	iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
	/* Verify we had enough resources to assign the vector */
	/* Will also flush the write out to device */
	return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
}

static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
				  struct virtio_pci_vq_info *info,
				  unsigned index,
				  void (*callback)(struct virtqueue *vq),
				  const char *name,
				  bool ctx,
				  u16 msix_vec)
{
	struct virtqueue *vq;
	u16 num;
	int err;
	u64 q_pfn;

	/* 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);

	info->msix_vector = msix_vec;

	/* create the vring */
	vq = vring_create_virtqueue(index, num,
				    VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
				    true, false, ctx,
				    vp_notify, callback, name);
	if (!vq)
		return ERR_PTR(-ENOMEM);

	q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
	if (q_pfn >> 32) {
		dev_err(&vp_dev->pci_dev->dev,
			"platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
			0x1ULL << (32 + PAGE_SHIFT - 30));
		err = -E2BIG;
		goto out_del_vq;
	}

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

	vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;

	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
		iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
		msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
		if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
			err = -EBUSY;
			goto out_deactivate;
		}
	}

	return vq;

out_deactivate:
	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
out_del_vq:
	vring_del_virtqueue(vq);
	return ERR_PTR(err);
}

static void del_vq(struct virtio_pci_vq_info *info)
{
	struct virtqueue *vq = info->vq;
	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);

	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);

	if (vp_dev->msix_enabled) {
		iowrite16(VIRTIO_MSI_NO_VECTOR,
			  vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
		/* Flush the write out to device */
		ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
	}

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

	vring_del_virtqueue(vq);
}

static const 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_vqs	= vp_find_vqs,
	.del_vqs	= vp_del_vqs,
	.get_features	= vp_get_features,
	.finalize_features = vp_finalize_features,
	.bus_name	= vp_bus_name,
	.set_vq_affinity = vp_set_vq_affinity,
	.get_vq_affinity = vp_get_vq_affinity,
};

/* the PCI probing function */
int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
{
	struct pci_dev *pci_dev = vp_dev->pci_dev;
	int rc;

	/* 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;
	}

	rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
	if (rc) {
		rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
	} else {
		/*
		 * The virtio ring base address is expressed as a 32-bit PFN,
		 * with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
		 */
		dma_set_coherent_mask(&pci_dev->dev,
				DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
	}

	if (rc)
		dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");

	rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
	if (rc)
		return rc;

	rc = -ENOMEM;
	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
	if (!vp_dev->ioaddr)
		goto err_iomap;

	vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;

	/* 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 subsystem ids */
	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
	vp_dev->vdev.id.device = pci_dev->subsystem_device;

	vp_dev->vdev.config = &virtio_pci_config_ops;

	vp_dev->config_vector = vp_config_vector;
	vp_dev->setup_vq = setup_vq;
	vp_dev->del_vq = del_vq;

	return 0;

err_iomap:
	pci_release_region(pci_dev, 0);
	return rc;
}

void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
{
	struct pci_dev *pci_dev = vp_dev->pci_dev;

	pci_iounmap(pci_dev, vp_dev->ioaddr);
	pci_release_region(pci_dev, 0);
}
Commit	Line	Data
f33f5fe2	1	// SPDX-License-Identifier: GPL-2.0-or-later
38eb4a29	2	/*
a90fdce9	3	* Virtio PCI driver - legacy device support
38eb4a29 MT	4	*
	5	* This module allows virtio devices to be used over a virtual PCI device.
	6	* This can be used with QEMU based VMMs like KVM or Xen.
	7	*
	8	* Copyright IBM Corp. 2007
a90fdce9	9	* Copyright Red Hat, Inc. 2014
38eb4a29 MT	10	*
	11	* Authors:
	12	* Anthony Liguori <aliguori@us.ibm.com>
a90fdce9 MT	13	* Rusty Russell <rusty@rustcorp.com.au>
a90fdce9 MT	14	* Michael S. Tsirkin <mst@redhat.com>
38eb4a29 MT	15	*/
38eb4a29 MT	16
5f4c9760	17	#include "virtio_pci_common.h"
38eb4a29	18
38eb4a29 MT	19	/* virtio config->get_features() implementation */
	20	static u64 vp_get_features(struct virtio_device *vdev)
	21	{
	22	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	23
	24	/* When someone needs more than 32 feature bits, we'll need to
	25	* steal a bit to indicate that the rest are somewhere else. */
	26	return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
	27	}
	28
	29	/* virtio config->finalize_features() implementation */
	30	static int vp_finalize_features(struct virtio_device *vdev)
	31	{
	32	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	33
	34	/* Give virtio_ring a chance to accept features. */
	35	vring_transport_features(vdev);
	36
	37	/* Make sure we don't have any features > 32 bits! */
	38	BUG_ON((u32)vdev->features != vdev->features);
	39
	40	/* We only support 32 feature bits. */
	41	iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
	42
	43	return 0;
	44	}
	45
	46	/* virtio config->get() implementation */
	47	static void vp_get(struct virtio_device *vdev, unsigned offset,
	48	void *buf, unsigned len)
	49	{
	50	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	51	void __iomem *ioaddr = vp_dev->ioaddr +
e8d26f29 DZ	52	VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
e8d26f29 DZ	53	offset;
38eb4a29 MT	54	u8 *ptr = buf;
	55	int i;
	56
	57	for (i = 0; i < len; i++)
	58	ptr[i] = ioread8(ioaddr + i);
	59	}
	60
	61	/* the config->set() implementation. it's symmetric to the config->get()
	62	* implementation */
	63	static void vp_set(struct virtio_device *vdev, unsigned offset,
	64	const void *buf, unsigned len)
	65	{
	66	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	67	void __iomem *ioaddr = vp_dev->ioaddr +
e8d26f29 DZ	68	VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
e8d26f29 DZ	69	offset;
38eb4a29 MT	70	const u8 *ptr = buf;
	71	int i;
	72
	73	for (i = 0; i < len; i++)
	74	iowrite8(ptr[i], ioaddr + i);
	75	}
	76
	77	/* config->{get,set}_status() implementations */
	78	static u8 vp_get_status(struct virtio_device *vdev)
	79	{
	80	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	81	return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
	82	}
	83
	84	static void vp_set_status(struct virtio_device *vdev, u8 status)
	85	{
	86	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	87	/* We should never be setting status to 0. */
	88	BUG_ON(status == 0);
	89	iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
	90	}
	91
	92	static void vp_reset(struct virtio_device *vdev)
	93	{
	94	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
	95	/* 0 status means a reset. */
	96	iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
	97	/* Flush out the status write, and flush in device writes,
	98	* including MSi-X interrupts, if any. */
	99	ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
	100	/* Flush pending VQ/configuration callbacks. */
	101	vp_synchronize_vectors(vdev);
	102	}
	103
	104	static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
	105	{
	106	/* Setup the vector used for configuration events */
	107	iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
	108	/* Verify we had enough resources to assign the vector */
	109	/* Will also flush the write out to device */
	110	return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
	111	}
	112
	113	static struct virtqueue setup_vq(struct virtio_pci_device vp_dev,
0a9b3f47	114	struct virtio_pci_vq_info *info,
38eb4a29 MT	115	unsigned index,
	116	void (callback)(struct virtqueue vq),
	117	const char *name,
f94682dd	118	bool ctx,
38eb4a29 MT	119	u16 msix_vec)
	120	{
	121	struct virtqueue *vq;
38eb4a29 MT	122	u16 num;
38eb4a29 MT	123	int err;
69599206	124	u64 q_pfn;
38eb4a29 MT	125
	126	/* Select the queue we're interested in */
	127	iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
	128
	129	/* Check if queue is either not available or already active. */
	130	num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
	131	if (!num \|\| ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
	132	return ERR_PTR(-ENOENT);
	133
0a9b3f47 MT	134	info->msix_vector = msix_vec;
0a9b3f47 MT	135
7a5589b2 AL	136	/* create the vring */
	137	vq = vring_create_virtqueue(index, num,
	138	VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
f94682dd MT	139	true, false, ctx,
f94682dd MT	140	vp_notify, callback, name);
7a5589b2	141	if (!vq)
38eb4a29 MT	142	return ERR_PTR(-ENOMEM);
38eb4a29 MT	143
69599206 SP	144	q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
	145	if (q_pfn >> 32) {
	146	dev_err(&vp_dev->pci_dev->dev,
	147	"platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
	148	0x1ULL << (32 + PAGE_SHIFT - 30));
	149	err = -E2BIG;
	150	goto out_del_vq;
	151	}
	152
38eb4a29	153	/* activate the queue */
69599206	154	iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
38eb4a29	155
38eb4a29 MT	156	vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
	157
	158	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
	159	iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
	160	msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
	161	if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
	162	err = -EBUSY;
7a5589b2	163	goto out_deactivate;
38eb4a29 MT	164	}
	165	}
	166
	167	return vq;
	168
7a5589b2	169	out_deactivate:
38eb4a29	170	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
69599206	171	out_del_vq:
7a5589b2	172	vring_del_virtqueue(vq);
38eb4a29 MT	173	return ERR_PTR(err);
	174	}
	175
0a9b3f47	176	static void del_vq(struct virtio_pci_vq_info *info)
38eb4a29	177	{
0a9b3f47	178	struct virtqueue *vq = info->vq;
38eb4a29	179	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
38eb4a29 MT	180
	181	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
	182
2008c154	183	if (vp_dev->msix_enabled) {
38eb4a29 MT	184	iowrite16(VIRTIO_MSI_NO_VECTOR,
	185	vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
	186	/* Flush the write out to device */
	187	ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
	188	}
	189
38eb4a29 MT	190	/* Select and deactivate the queue */
	191	iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
	192
7a5589b2	193	vring_del_virtqueue(vq);
38eb4a29 MT	194	}
	195
	196	static const struct virtio_config_ops virtio_pci_config_ops = {
	197	.get = vp_get,
	198	.set = vp_set,
	199	.get_status = vp_get_status,
	200	.set_status = vp_set_status,
	201	.reset = vp_reset,
	202	.find_vqs = vp_find_vqs,
	203	.del_vqs = vp_del_vqs,
	204	.get_features = vp_get_features,
	205	.finalize_features = vp_finalize_features,
	206	.bus_name = vp_bus_name,
	207	.set_vq_affinity = vp_set_vq_affinity,
bbaba479	208	.get_vq_affinity = vp_get_vq_affinity,
38eb4a29 MT	209	};
	210
	211	/* the PCI probing function */
ff31d2e2	212	int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
38eb4a29	213	{
ff31d2e2	214	struct pci_dev *pci_dev = vp_dev->pci_dev;
59a5b0f7	215	int rc;
38eb4a29 MT	216
	217	/* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
	218	if (pci_dev->device < 0x1000 \|\| pci_dev->device > 0x103f)
	219	return -ENODEV;
	220
	221	if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
	222	printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
	223	VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
	224	return -ENODEV;
	225	}
	226
a0be1db4 WD	227	rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
	228	if (rc) {
	229	rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
	230	} else {
	231	/*
	232	* The virtio ring base address is expressed as a 32-bit PFN,
	233	* with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
	234	*/
	235	dma_set_coherent_mask(&pci_dev->dev,
	236	DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
	237	}
	238
7a5589b2 AL	239	if (rc)
	240	dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
	241
59a5b0f7 GH	242	rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
	243	if (rc)
	244	return rc;
	245
	246	rc = -ENOMEM;
38eb4a29	247	vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
ff31d2e2	248	if (!vp_dev->ioaddr)
59a5b0f7	249	goto err_iomap;
38eb4a29 MT	250
	251	vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
	252
38eb4a29 MT	253	/* we use the subsystem vendor/device id as the virtio vendor/device
	254	* id. this allows us to use the same PCI vendor/device id for all
	255	* virtio devices and to identify the particular virtio driver by
	256	* the subsystem ids */
	257	vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
	258	vp_dev->vdev.id.device = pci_dev->subsystem_device;
	259
ff31d2e2 MT	260	vp_dev->vdev.config = &virtio_pci_config_ops;
ff31d2e2 MT	261
38eb4a29 MT	262	vp_dev->config_vector = vp_config_vector;
	263	vp_dev->setup_vq = setup_vq;
	264	vp_dev->del_vq = del_vq;
	265
38eb4a29	266	return 0;
59a5b0f7 GH	267
	268	err_iomap:
	269	pci_release_region(pci_dev, 0);
	270	return rc;
38eb4a29 MT	271	}
38eb4a29 MT	272
ff31d2e2	273	void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
38eb4a29	274	{
ff31d2e2	275	struct pci_dev *pci_dev = vp_dev->pci_dev;
38eb4a29	276
38eb4a29	277	pci_iounmap(pci_dev, vp_dev->ioaddr);
59a5b0f7	278	pci_release_region(pci_dev, 0);
38eb4a29	279	}