1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * VIRTIO based driver for vDPA device 4 * 5 * Copyright (c) 2020, Red Hat. All rights reserved. 6 * Author: Jason Wang <jasowang@redhat.com> 7 * 8 */ 9 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/device.h> 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/uuid.h> 16 #include <linux/virtio.h> 17 #include <linux/vdpa.h> 18 #include <linux/virtio_config.h> 19 #include <linux/virtio_ring.h> 20 21 #define MOD_VERSION "0.1" 22 #define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>" 23 #define MOD_DESC "vDPA bus driver for virtio devices" 24 #define MOD_LICENSE "GPL v2" 25 26 struct virtio_vdpa_device { 27 struct virtio_device vdev; 28 struct vdpa_device *vdpa; 29 u64 features; 30 31 /* The lock to protect virtqueue list */ 32 spinlock_t lock; 33 /* List of virtio_vdpa_vq_info */ 34 struct list_head virtqueues; 35 }; 36 37 struct virtio_vdpa_vq_info { 38 /* the actual virtqueue */ 39 struct virtqueue *vq; 40 41 /* the list node for the virtqueues list */ 42 struct list_head node; 43 }; 44 45 static inline struct virtio_vdpa_device * 46 to_virtio_vdpa_device(struct virtio_device *dev) 47 { 48 return container_of(dev, struct virtio_vdpa_device, vdev); 49 } 50 51 static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev) 52 { 53 return to_virtio_vdpa_device(vdev)->vdpa; 54 } 55 56 static void virtio_vdpa_get(struct virtio_device *vdev, unsigned offset, 57 void *buf, unsigned len) 58 { 59 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 60 61 vdpa_get_config(vdpa, offset, buf, len); 62 } 63 64 static void virtio_vdpa_set(struct virtio_device *vdev, unsigned offset, 65 const void *buf, unsigned len) 66 { 67 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 68 const struct vdpa_config_ops *ops = vdpa->config; 69 70 ops->set_config(vdpa, offset, buf, len); 71 } 72 73 static u32 virtio_vdpa_generation(struct virtio_device *vdev) 74 { 75 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 76 const struct vdpa_config_ops *ops = vdpa->config; 77 78 if (ops->get_generation) 79 return ops->get_generation(vdpa); 80 81 return 0; 82 } 83 84 static u8 virtio_vdpa_get_status(struct virtio_device *vdev) 85 { 86 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 87 const struct vdpa_config_ops *ops = vdpa->config; 88 89 return ops->get_status(vdpa); 90 } 91 92 static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status) 93 { 94 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 95 const struct vdpa_config_ops *ops = vdpa->config; 96 97 return ops->set_status(vdpa, status); 98 } 99 100 static void virtio_vdpa_reset(struct virtio_device *vdev) 101 { 102 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 103 104 vdpa_reset(vdpa); 105 } 106 107 static bool virtio_vdpa_notify(struct virtqueue *vq) 108 { 109 struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev); 110 const struct vdpa_config_ops *ops = vdpa->config; 111 112 ops->kick_vq(vdpa, vq->index); 113 114 return true; 115 } 116 117 static irqreturn_t virtio_vdpa_config_cb(void *private) 118 { 119 struct virtio_vdpa_device *vd_dev = private; 120 121 virtio_config_changed(&vd_dev->vdev); 122 123 return IRQ_HANDLED; 124 } 125 126 static irqreturn_t virtio_vdpa_virtqueue_cb(void *private) 127 { 128 struct virtio_vdpa_vq_info *info = private; 129 130 return vring_interrupt(0, info->vq); 131 } 132 133 static struct virtqueue * 134 virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, 135 void (*callback)(struct virtqueue *vq), 136 const char *name, bool ctx) 137 { 138 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 139 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 140 const struct vdpa_config_ops *ops = vdpa->config; 141 struct virtio_vdpa_vq_info *info; 142 struct vdpa_callback cb; 143 struct virtqueue *vq; 144 u64 desc_addr, driver_addr, device_addr; 145 /* Assume split virtqueue, switch to packed if necessary */ 146 struct vdpa_vq_state state = {0}; 147 unsigned long flags; 148 u32 align, num; 149 int err; 150 151 if (!name) 152 return NULL; 153 154 /* Queue shouldn't already be set up. */ 155 if (ops->get_vq_ready(vdpa, index)) 156 return ERR_PTR(-ENOENT); 157 158 /* Allocate and fill out our active queue description */ 159 info = kmalloc(sizeof(*info), GFP_KERNEL); 160 if (!info) 161 return ERR_PTR(-ENOMEM); 162 163 num = ops->get_vq_num_max(vdpa); 164 if (num == 0) { 165 err = -ENOENT; 166 goto error_new_virtqueue; 167 } 168 169 /* Create the vring */ 170 align = ops->get_vq_align(vdpa); 171 vq = vring_create_virtqueue(index, num, align, vdev, 172 true, true, ctx, 173 virtio_vdpa_notify, callback, name); 174 if (!vq) { 175 err = -ENOMEM; 176 goto error_new_virtqueue; 177 } 178 179 /* Setup virtqueue callback */ 180 cb.callback = virtio_vdpa_virtqueue_cb; 181 cb.private = info; 182 ops->set_vq_cb(vdpa, index, &cb); 183 ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq)); 184 185 desc_addr = virtqueue_get_desc_addr(vq); 186 driver_addr = virtqueue_get_avail_addr(vq); 187 device_addr = virtqueue_get_used_addr(vq); 188 189 if (ops->set_vq_address(vdpa, index, 190 desc_addr, driver_addr, 191 device_addr)) { 192 err = -EINVAL; 193 goto err_vq; 194 } 195 196 /* reset virtqueue state index */ 197 if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 198 struct vdpa_vq_state_packed *s = &state.packed; 199 200 s->last_avail_counter = 1; 201 s->last_avail_idx = 0; 202 s->last_used_counter = 1; 203 s->last_used_idx = 0; 204 } 205 err = ops->set_vq_state(vdpa, index, &state); 206 if (err) 207 goto err_vq; 208 209 ops->set_vq_ready(vdpa, index, 1); 210 211 vq->priv = info; 212 info->vq = vq; 213 214 spin_lock_irqsave(&vd_dev->lock, flags); 215 list_add(&info->node, &vd_dev->virtqueues); 216 spin_unlock_irqrestore(&vd_dev->lock, flags); 217 218 return vq; 219 220 err_vq: 221 vring_del_virtqueue(vq); 222 error_new_virtqueue: 223 ops->set_vq_ready(vdpa, index, 0); 224 /* VDPA driver should make sure vq is stopeed here */ 225 WARN_ON(ops->get_vq_ready(vdpa, index)); 226 kfree(info); 227 return ERR_PTR(err); 228 } 229 230 static void virtio_vdpa_del_vq(struct virtqueue *vq) 231 { 232 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev); 233 struct vdpa_device *vdpa = vd_dev->vdpa; 234 const struct vdpa_config_ops *ops = vdpa->config; 235 struct virtio_vdpa_vq_info *info = vq->priv; 236 unsigned int index = vq->index; 237 unsigned long flags; 238 239 spin_lock_irqsave(&vd_dev->lock, flags); 240 list_del(&info->node); 241 spin_unlock_irqrestore(&vd_dev->lock, flags); 242 243 /* Select and deactivate the queue (best effort) */ 244 ops->set_vq_ready(vdpa, index, 0); 245 246 vring_del_virtqueue(vq); 247 248 kfree(info); 249 } 250 251 static void virtio_vdpa_del_vqs(struct virtio_device *vdev) 252 { 253 struct virtqueue *vq, *n; 254 255 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 256 virtio_vdpa_del_vq(vq); 257 } 258 259 static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs, 260 struct virtqueue *vqs[], 261 vq_callback_t *callbacks[], 262 const char * const names[], 263 const bool *ctx, 264 struct irq_affinity *desc) 265 { 266 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 267 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 268 const struct vdpa_config_ops *ops = vdpa->config; 269 struct vdpa_callback cb; 270 int i, err, queue_idx = 0; 271 272 for (i = 0; i < nvqs; ++i) { 273 if (!names[i]) { 274 vqs[i] = NULL; 275 continue; 276 } 277 278 vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, 279 callbacks[i], names[i], ctx ? 280 ctx[i] : false); 281 if (IS_ERR(vqs[i])) { 282 err = PTR_ERR(vqs[i]); 283 goto err_setup_vq; 284 } 285 } 286 287 cb.callback = virtio_vdpa_config_cb; 288 cb.private = vd_dev; 289 ops->set_config_cb(vdpa, &cb); 290 291 return 0; 292 293 err_setup_vq: 294 virtio_vdpa_del_vqs(vdev); 295 return err; 296 } 297 298 static u64 virtio_vdpa_get_features(struct virtio_device *vdev) 299 { 300 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 301 const struct vdpa_config_ops *ops = vdpa->config; 302 303 return ops->get_features(vdpa); 304 } 305 306 static int virtio_vdpa_finalize_features(struct virtio_device *vdev) 307 { 308 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 309 310 /* Give virtio_ring a chance to accept features. */ 311 vring_transport_features(vdev); 312 313 return vdpa_set_features(vdpa, vdev->features); 314 } 315 316 static const char *virtio_vdpa_bus_name(struct virtio_device *vdev) 317 { 318 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 319 struct vdpa_device *vdpa = vd_dev->vdpa; 320 321 return dev_name(&vdpa->dev); 322 } 323 324 static const struct virtio_config_ops virtio_vdpa_config_ops = { 325 .get = virtio_vdpa_get, 326 .set = virtio_vdpa_set, 327 .generation = virtio_vdpa_generation, 328 .get_status = virtio_vdpa_get_status, 329 .set_status = virtio_vdpa_set_status, 330 .reset = virtio_vdpa_reset, 331 .find_vqs = virtio_vdpa_find_vqs, 332 .del_vqs = virtio_vdpa_del_vqs, 333 .get_features = virtio_vdpa_get_features, 334 .finalize_features = virtio_vdpa_finalize_features, 335 .bus_name = virtio_vdpa_bus_name, 336 }; 337 338 static void virtio_vdpa_release_dev(struct device *_d) 339 { 340 struct virtio_device *vdev = 341 container_of(_d, struct virtio_device, dev); 342 struct virtio_vdpa_device *vd_dev = 343 container_of(vdev, struct virtio_vdpa_device, vdev); 344 345 kfree(vd_dev); 346 } 347 348 static int virtio_vdpa_probe(struct vdpa_device *vdpa) 349 { 350 const struct vdpa_config_ops *ops = vdpa->config; 351 struct virtio_vdpa_device *vd_dev, *reg_dev = NULL; 352 int ret = -EINVAL; 353 354 vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL); 355 if (!vd_dev) 356 return -ENOMEM; 357 358 vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa); 359 vd_dev->vdev.dev.release = virtio_vdpa_release_dev; 360 vd_dev->vdev.config = &virtio_vdpa_config_ops; 361 vd_dev->vdpa = vdpa; 362 INIT_LIST_HEAD(&vd_dev->virtqueues); 363 spin_lock_init(&vd_dev->lock); 364 365 vd_dev->vdev.id.device = ops->get_device_id(vdpa); 366 if (vd_dev->vdev.id.device == 0) 367 goto err; 368 369 vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa); 370 ret = register_virtio_device(&vd_dev->vdev); 371 reg_dev = vd_dev; 372 if (ret) 373 goto err; 374 375 vdpa_set_drvdata(vdpa, vd_dev); 376 377 return 0; 378 379 err: 380 if (reg_dev) 381 put_device(&vd_dev->vdev.dev); 382 else 383 kfree(vd_dev); 384 return ret; 385 } 386 387 static void virtio_vdpa_remove(struct vdpa_device *vdpa) 388 { 389 struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa); 390 391 unregister_virtio_device(&vd_dev->vdev); 392 } 393 394 static struct vdpa_driver virtio_vdpa_driver = { 395 .driver = { 396 .name = "virtio_vdpa", 397 }, 398 .probe = virtio_vdpa_probe, 399 .remove = virtio_vdpa_remove, 400 }; 401 402 module_vdpa_driver(virtio_vdpa_driver); 403 404 MODULE_VERSION(MOD_VERSION); 405 MODULE_LICENSE(MOD_LICENSE); 406 MODULE_AUTHOR(MOD_AUTHOR); 407 MODULE_DESCRIPTION(MOD_DESC); 408