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Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +02001/*
Michael S. Tsirkina90fdce2014-12-08 12:31:02 +02002 * Virtio PCI driver - legacy device support
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +02003 *
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
Michael S. Tsirkina90fdce2014-12-08 12:31:02 +02008 * Copyright Red Hat, Inc. 2014
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +02009 *
10 * Authors:
11 * Anthony Liguori <aliguori@us.ibm.com>
Michael S. Tsirkina90fdce2014-12-08 12:31:02 +020012 * Rusty Russell <rusty@rustcorp.com.au>
13 * Michael S. Tsirkin <mst@redhat.com>
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +020014 *
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.
17 *
18 */
19
Michael S. Tsirkin5f4c9762014-12-08 16:39:45 +020020#include "virtio_pci_common.h"
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +020021
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +020022/* virtio config->get_features() implementation */
23static u64 vp_get_features(struct virtio_device *vdev)
24{
25 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
26
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);
30}
31
32/* virtio config->finalize_features() implementation */
33static int vp_finalize_features(struct virtio_device *vdev)
34{
35 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
36
37 /* Give virtio_ring a chance to accept features. */
38 vring_transport_features(vdev);
39
40 /* Make sure we don't have any features > 32 bits! */
41 BUG_ON((u32)vdev->features != vdev->features);
42
43 /* We only support 32 feature bits. */
44 iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
45
46 return 0;
47}
48
49/* virtio config->get() implementation */
50static void vp_get(struct virtio_device *vdev, unsigned offset,
51 void *buf, unsigned len)
52{
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;
56 u8 *ptr = buf;
57 int i;
58
59 for (i = 0; i < len; i++)
60 ptr[i] = ioread8(ioaddr + i);
61}
62
63/* the config->set() implementation. it's symmetric to the config->get()
64 * implementation */
65static void vp_set(struct virtio_device *vdev, unsigned offset,
66 const void *buf, unsigned len)
67{
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;
71 const u8 *ptr = buf;
72 int i;
73
74 for (i = 0; i < len; i++)
75 iowrite8(ptr[i], ioaddr + i);
76}
77
78/* config->{get,set}_status() implementations */
79static u8 vp_get_status(struct virtio_device *vdev)
80{
81 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
82 return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
83}
84
85static void vp_set_status(struct virtio_device *vdev, u8 status)
86{
87 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
88 /* We should never be setting status to 0. */
89 BUG_ON(status == 0);
90 iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
91}
92
93static void vp_reset(struct virtio_device *vdev)
94{
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);
103}
104
105static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
106{
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);
112}
113
114static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
115 struct virtio_pci_vq_info *info,
116 unsigned index,
117 void (*callback)(struct virtqueue *vq),
118 const char *name,
119 u16 msix_vec)
120{
121 struct virtqueue *vq;
122 unsigned long size;
123 u16 num;
124 int err;
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
134 info->num = num;
135 info->msix_vector = msix_vec;
136
137 size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
138 info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
139 if (info->queue == NULL)
140 return ERR_PTR(-ENOMEM);
141
142 /* activate the queue */
143 iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
144 vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
145
146 /* create the vring */
147 vq = vring_new_virtqueue(index, info->num,
148 VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
149 true, info->queue, vp_notify, callback, name);
150 if (!vq) {
151 err = -ENOMEM;
152 goto out_activate_queue;
153 }
154
155 vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
156
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) {
161 err = -EBUSY;
162 goto out_assign;
163 }
164 }
165
166 return vq;
167
168out_assign:
169 vring_del_virtqueue(vq);
170out_activate_queue:
171 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
172 free_pages_exact(info->queue, size);
173 return ERR_PTR(err);
174}
175
176static void del_vq(struct virtio_pci_vq_info *info)
177{
178 struct virtqueue *vq = info->vq;
179 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
180 unsigned long size;
181
182 iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
183
184 if (vp_dev->msix_enabled) {
185 iowrite16(VIRTIO_MSI_NO_VECTOR,
186 vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
187 /* Flush the write out to device */
188 ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
189 }
190
191 vring_del_virtqueue(vq);
192
193 /* Select and deactivate the queue */
194 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
195
196 size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
197 free_pages_exact(info->queue, size);
198}
199
200static const struct virtio_config_ops virtio_pci_config_ops = {
201 .get = vp_get,
202 .set = vp_set,
203 .get_status = vp_get_status,
204 .set_status = vp_set_status,
205 .reset = vp_reset,
206 .find_vqs = vp_find_vqs,
207 .del_vqs = vp_del_vqs,
208 .get_features = vp_get_features,
209 .finalize_features = vp_finalize_features,
210 .bus_name = vp_bus_name,
211 .set_vq_affinity = vp_set_vq_affinity,
212};
213
214/* the PCI probing function */
Michael S. Tsirkinff31d2e2015-01-13 11:23:32 +0200215int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200216{
Michael S. Tsirkinff31d2e2015-01-13 11:23:32 +0200217 struct pci_dev *pci_dev = vp_dev->pci_dev;
Gerd Hoffmann59a5b0f72015-06-24 07:54:15 +0200218 int rc;
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200219
220 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
221 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
222 return -ENODEV;
223
224 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
225 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
226 VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
227 return -ENODEV;
228 }
229
Gerd Hoffmann59a5b0f72015-06-24 07:54:15 +0200230 rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
231 if (rc)
232 return rc;
233
234 rc = -ENOMEM;
Michael S. Tsirkinff31d2e2015-01-13 11:23:32 +0200235 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
236 if (!vp_dev->ioaddr)
Gerd Hoffmann59a5b0f72015-06-24 07:54:15 +0200237 goto err_iomap;
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200238
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200239 vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
240
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200241 /* we use the subsystem vendor/device id as the virtio vendor/device
242 * id. this allows us to use the same PCI vendor/device id for all
243 * virtio devices and to identify the particular virtio driver by
244 * the subsystem ids */
245 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
246 vp_dev->vdev.id.device = pci_dev->subsystem_device;
247
Michael S. Tsirkinff31d2e2015-01-13 11:23:32 +0200248 vp_dev->vdev.config = &virtio_pci_config_ops;
249
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200250 vp_dev->config_vector = vp_config_vector;
251 vp_dev->setup_vq = setup_vq;
252 vp_dev->del_vq = del_vq;
253
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200254 return 0;
Gerd Hoffmann59a5b0f72015-06-24 07:54:15 +0200255
256err_iomap:
257 pci_release_region(pci_dev, 0);
258 return rc;
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200259}
260
Michael S. Tsirkinff31d2e2015-01-13 11:23:32 +0200261void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200262{
Michael S. Tsirkinff31d2e2015-01-13 11:23:32 +0200263 struct pci_dev *pci_dev = vp_dev->pci_dev;
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200264
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200265 pci_iounmap(pci_dev, vp_dev->ioaddr);
Gerd Hoffmann59a5b0f72015-06-24 07:54:15 +0200266 pci_release_region(pci_dev, 0);
Michael S. Tsirkin38eb4a22014-12-07 18:41:16 +0200267}