1 /* 2 * Virtio PCI driver - legacy device support 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 * Copyright Red Hat, Inc. 2014 9 * 10 * Authors: 11 * Anthony Liguori <aliguori@us.ibm.com> 12 * Rusty Russell <rusty@rustcorp.com.au> 13 * Michael S. Tsirkin <mst@redhat.com> 14 * 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 20 #include "virtio_pci_common.h" 21 22 /* virtio config->get_features() implementation */ 23 static 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 */ 33 static 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 */ 50 static 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 */ 65 static 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 */ 79 static 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 85 static 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 93 static 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 } 104 105 static 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 } 113 114 static 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; 167 168 out_assign: 169 vring_del_virtqueue(vq); 170 out_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 } 175 176 static 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 } 199 200 static 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 static void virtio_pci_release_dev(struct device *_d) 215 { 216 struct virtio_device *vdev = dev_to_virtio(_d); 217 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 218 219 /* As struct device is a kobject, it's not safe to 220 * free the memory (including the reference counter itself) 221 * until it's release callback. */ 222 kfree(vp_dev); 223 } 224 225 /* the PCI probing function */ 226 int virtio_pci_legacy_probe(struct pci_dev *pci_dev, 227 const struct pci_device_id *id) 228 { 229 struct virtio_pci_device *vp_dev; 230 int err; 231 232 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */ 233 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f) 234 return -ENODEV; 235 236 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) { 237 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n", 238 VIRTIO_PCI_ABI_VERSION, pci_dev->revision); 239 return -ENODEV; 240 } 241 242 /* allocate our structure and fill it out */ 243 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL); 244 if (vp_dev == NULL) 245 return -ENOMEM; 246 247 vp_dev->vdev.dev.parent = &pci_dev->dev; 248 vp_dev->vdev.dev.release = virtio_pci_release_dev; 249 vp_dev->vdev.config = &virtio_pci_config_ops; 250 vp_dev->pci_dev = pci_dev; 251 INIT_LIST_HEAD(&vp_dev->virtqueues); 252 spin_lock_init(&vp_dev->lock); 253 254 /* Disable MSI/MSIX to bring device to a known good state. */ 255 pci_msi_off(pci_dev); 256 257 /* enable the device */ 258 err = pci_enable_device(pci_dev); 259 if (err) 260 goto out; 261 262 err = pci_request_regions(pci_dev, "virtio-pci"); 263 if (err) 264 goto out_enable_device; 265 266 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0); 267 if (vp_dev->ioaddr == NULL) { 268 err = -ENOMEM; 269 goto out_req_regions; 270 } 271 272 vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR; 273 274 pci_set_drvdata(pci_dev, vp_dev); 275 pci_set_master(pci_dev); 276 277 /* we use the subsystem vendor/device id as the virtio vendor/device 278 * id. this allows us to use the same PCI vendor/device id for all 279 * virtio devices and to identify the particular virtio driver by 280 * the subsystem ids */ 281 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor; 282 vp_dev->vdev.id.device = pci_dev->subsystem_device; 283 284 vp_dev->config_vector = vp_config_vector; 285 vp_dev->setup_vq = setup_vq; 286 vp_dev->del_vq = del_vq; 287 288 /* finally register the virtio device */ 289 err = register_virtio_device(&vp_dev->vdev); 290 if (err) 291 goto out_set_drvdata; 292 293 return 0; 294 295 out_set_drvdata: 296 pci_iounmap(pci_dev, vp_dev->ioaddr); 297 out_req_regions: 298 pci_release_regions(pci_dev); 299 out_enable_device: 300 pci_disable_device(pci_dev); 301 out: 302 kfree(vp_dev); 303 return err; 304 } 305 306 void virtio_pci_legacy_remove(struct pci_dev *pci_dev) 307 { 308 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); 309 310 unregister_virtio_device(&vp_dev->vdev); 311 312 vp_del_vqs(&vp_dev->vdev); 313 pci_iounmap(pci_dev, vp_dev->ioaddr); 314 pci_release_regions(pci_dev); 315 pci_disable_device(pci_dev); 316 } 317