2 * Virtio PCI driver - legacy device support
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.
7 * Copyright IBM Corp. 2007
8 * Copyright Red Hat, Inc. 2014
11 * Anthony Liguori <aliguori@us.ibm.com>
12 * Rusty Russell <rusty@rustcorp.com.au>
13 * Michael S. Tsirkin <mst@redhat.com>
15 * This work is licensed under the terms of the GNU GPL, version 2 or later.
16 * See the COPYING file in the top-level directory.
20 #include "virtio_pci_common.h"
22 /* virtio config->get_features() implementation */
23 static u64 vp_get_features(struct virtio_device *vdev)
25 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
27 /* When someone needs more than 32 feature bits, we'll need to
28 * steal a bit to indicate that the rest are somewhere else. */
29 return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
32 /* virtio config->finalize_features() implementation */
33 static int vp_finalize_features(struct virtio_device *vdev)
35 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
37 /* Give virtio_ring a chance to accept features. */
38 vring_transport_features(vdev);
40 /* Make sure we don't have any features > 32 bits! */
41 BUG_ON((u32)vdev->features != vdev->features);
43 /* We only support 32 feature bits. */
44 iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
49 /* virtio config->get() implementation */
50 static void vp_get(struct virtio_device *vdev, unsigned offset,
51 void *buf, unsigned len)
53 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
54 void __iomem *ioaddr = vp_dev->ioaddr +
55 VIRTIO_PCI_CONFIG(vp_dev) + offset;
59 for (i = 0; i < len; i++)
60 ptr[i] = ioread8(ioaddr + i);
63 /* the config->set() implementation. it's symmetric to the config->get()
65 static void vp_set(struct virtio_device *vdev, unsigned offset,
66 const void *buf, unsigned len)
68 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
69 void __iomem *ioaddr = vp_dev->ioaddr +
70 VIRTIO_PCI_CONFIG(vp_dev) + offset;
74 for (i = 0; i < len; i++)
75 iowrite8(ptr[i], ioaddr + i);
78 /* config->{get,set}_status() implementations */
79 static u8 vp_get_status(struct virtio_device *vdev)
81 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
82 return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
85 static void vp_set_status(struct virtio_device *vdev, u8 status)
87 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
88 /* We should never be setting status to 0. */
90 iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
93 static void vp_reset(struct virtio_device *vdev)
95 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
96 /* 0 status means a reset. */
97 iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
98 /* Flush out the status write, and flush in device writes,
99 * including MSi-X interrupts, if any. */
100 ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
101 /* Flush pending VQ/configuration callbacks. */
102 vp_synchronize_vectors(vdev);
105 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
107 /* Setup the vector used for configuration events */
108 iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
109 /* Verify we had enough resources to assign the vector */
110 /* Will also flush the write out to device */
111 return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
114 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
115 struct virtio_pci_vq_info *info,
117 void (*callback)(struct virtqueue *vq),
121 struct virtqueue *vq;
126 /* Select the queue we're interested in */
127 iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
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);
134 info->msix_vector = msix_vec;
136 /* create the vring */
137 vq = vring_create_virtqueue(index, num,
138 VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
139 true, false, vp_notify, callback, name);
141 return ERR_PTR(-ENOMEM);
143 q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
145 dev_err(&vp_dev->pci_dev->dev,
146 "platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
147 0x1ULL << (32 + PAGE_SHIFT - 30));
152 /* activate the queue */
153 iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
155 vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
157 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
158 iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
159 msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
160 if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
169 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
171 vring_del_virtqueue(vq);
175 static void del_vq(struct virtio_pci_vq_info *info)
177 struct virtqueue *vq = info->vq;
178 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
180 iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
182 if (vp_dev->msix_enabled) {
183 iowrite16(VIRTIO_MSI_NO_VECTOR,
184 vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
185 /* Flush the write out to device */
186 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
189 /* Select and deactivate the queue */
190 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
192 vring_del_virtqueue(vq);
195 static const struct virtio_config_ops virtio_pci_config_ops = {
198 .get_status = vp_get_status,
199 .set_status = vp_set_status,
201 .find_vqs = vp_find_vqs,
202 .del_vqs = vp_del_vqs,
203 .get_features = vp_get_features,
204 .finalize_features = vp_finalize_features,
205 .bus_name = vp_bus_name,
206 .set_vq_affinity = vp_set_vq_affinity,
209 /* the PCI probing function */
210 int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
212 struct pci_dev *pci_dev = vp_dev->pci_dev;
215 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
216 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
219 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
220 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
221 VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
225 rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
227 rc = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(32));
230 * The virtio ring base address is expressed as a 32-bit PFN,
231 * with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
233 dma_set_coherent_mask(&pci_dev->dev,
234 DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
238 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
240 rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
245 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
249 vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
251 /* we use the subsystem vendor/device id as the virtio vendor/device
252 * id. this allows us to use the same PCI vendor/device id for all
253 * virtio devices and to identify the particular virtio driver by
254 * the subsystem ids */
255 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
256 vp_dev->vdev.id.device = pci_dev->subsystem_device;
258 vp_dev->vdev.config = &virtio_pci_config_ops;
260 vp_dev->config_vector = vp_config_vector;
261 vp_dev->setup_vq = setup_vq;
262 vp_dev->del_vq = del_vq;
267 pci_release_region(pci_dev, 0);
271 void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
273 struct pci_dev *pci_dev = vp_dev->pci_dev;
275 pci_iounmap(pci_dev, vp_dev->ioaddr);
276 pci_release_region(pci_dev, 0);