David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 2 | /* |
| 3 | * Virtio PCI driver - legacy device support |
| 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 |
| 9 | * Copyright Red Hat, Inc. 2014 |
| 10 | * |
| 11 | * Authors: |
| 12 | * Anthony Liguori <aliguori@us.ibm.com> |
| 13 | * Rusty Russell <rusty@rustcorp.com.au> |
| 14 | * Michael S. Tsirkin <mst@redhat.com> |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 15 | */ |
| 16 | |
| 17 | #include "virtio_pci_common.h" |
| 18 | |
| 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 + |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 52 | VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) + |
| 53 | offset; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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 + |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 68 | VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) + |
| 69 | offset; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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, |
| 114 | struct virtio_pci_vq_info *info, |
| 115 | unsigned index, |
| 116 | void (*callback)(struct virtqueue *vq), |
| 117 | const char *name, |
| 118 | bool ctx, |
| 119 | u16 msix_vec) |
| 120 | { |
| 121 | struct virtqueue *vq; |
| 122 | u16 num; |
| 123 | int err; |
| 124 | u64 q_pfn; |
| 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->msix_vector = msix_vec; |
| 135 | |
| 136 | /* create the vring */ |
| 137 | vq = vring_create_virtqueue(index, num, |
| 138 | VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev, |
| 139 | true, false, ctx, |
| 140 | vp_notify, callback, name); |
| 141 | if (!vq) |
| 142 | return ERR_PTR(-ENOMEM); |
| 143 | |
| 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 | |
| 153 | /* activate the queue */ |
| 154 | iowrite32(q_pfn, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); |
| 155 | |
| 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; |
| 163 | goto out_deactivate; |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | return vq; |
| 168 | |
| 169 | out_deactivate: |
| 170 | iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); |
| 171 | out_del_vq: |
| 172 | vring_del_virtqueue(vq); |
| 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 | |
| 181 | iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); |
| 182 | |
| 183 | if (vp_dev->msix_enabled) { |
| 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 | |
| 190 | /* Select and deactivate the queue */ |
| 191 | iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); |
| 192 | |
| 193 | vring_del_virtqueue(vq); |
| 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, |
| 208 | .get_vq_affinity = vp_get_vq_affinity, |
| 209 | }; |
| 210 | |
| 211 | /* the PCI probing function */ |
| 212 | int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) |
| 213 | { |
| 214 | struct pci_dev *pci_dev = vp_dev->pci_dev; |
| 215 | int rc; |
| 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 | |
| 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 | |
| 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 | |
| 242 | rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy"); |
| 243 | if (rc) |
| 244 | return rc; |
| 245 | |
| 246 | rc = -ENOMEM; |
| 247 | vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0); |
| 248 | if (!vp_dev->ioaddr) |
| 249 | goto err_iomap; |
| 250 | |
| 251 | vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR; |
| 252 | |
| 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 | |
| 260 | vp_dev->vdev.config = &virtio_pci_config_ops; |
| 261 | |
| 262 | vp_dev->config_vector = vp_config_vector; |
| 263 | vp_dev->setup_vq = setup_vq; |
| 264 | vp_dev->del_vq = del_vq; |
| 265 | |
| 266 | return 0; |
| 267 | |
| 268 | err_iomap: |
| 269 | pci_release_region(pci_dev, 0); |
| 270 | return rc; |
| 271 | } |
| 272 | |
| 273 | void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) |
| 274 | { |
| 275 | struct pci_dev *pci_dev = vp_dev->pci_dev; |
| 276 | |
| 277 | pci_iounmap(pci_dev, vp_dev->ioaddr); |
| 278 | pci_release_region(pci_dev, 0); |
| 279 | } |