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 int offset, 57 void *buf, unsigned int 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 int offset, 65 const void *buf, unsigned int len) 66 { 67 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 68 69 vdpa_set_config(vdpa, offset, buf, len); 70 } 71 72 static u32 virtio_vdpa_generation(struct virtio_device *vdev) 73 { 74 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 75 const struct vdpa_config_ops *ops = vdpa->config; 76 77 if (ops->get_generation) 78 return ops->get_generation(vdpa); 79 80 return 0; 81 } 82 83 static u8 virtio_vdpa_get_status(struct virtio_device *vdev) 84 { 85 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 86 const struct vdpa_config_ops *ops = vdpa->config; 87 88 return ops->get_status(vdpa); 89 } 90 91 static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status) 92 { 93 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 94 95 return vdpa_set_status(vdpa, status); 96 } 97 98 static void virtio_vdpa_reset(struct virtio_device *vdev) 99 { 100 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 101 102 vdpa_reset(vdpa); 103 } 104 105 static bool virtio_vdpa_notify(struct virtqueue *vq) 106 { 107 struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev); 108 const struct vdpa_config_ops *ops = vdpa->config; 109 110 ops->kick_vq(vdpa, vq->index); 111 112 return true; 113 } 114 115 static irqreturn_t virtio_vdpa_config_cb(void *private) 116 { 117 struct virtio_vdpa_device *vd_dev = private; 118 119 virtio_config_changed(&vd_dev->vdev); 120 121 return IRQ_HANDLED; 122 } 123 124 static irqreturn_t virtio_vdpa_virtqueue_cb(void *private) 125 { 126 struct virtio_vdpa_vq_info *info = private; 127 128 return vring_interrupt(0, info->vq); 129 } 130 131 static struct virtqueue * 132 virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, 133 void (*callback)(struct virtqueue *vq), 134 const char *name, bool ctx) 135 { 136 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 137 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 138 const struct vdpa_config_ops *ops = vdpa->config; 139 struct virtio_vdpa_vq_info *info; 140 struct vdpa_callback cb; 141 struct virtqueue *vq; 142 u64 desc_addr, driver_addr, device_addr; 143 /* Assume split virtqueue, switch to packed if necessary */ 144 struct vdpa_vq_state state = {0}; 145 unsigned long flags; 146 u32 align, max_num, min_num = 1; 147 bool may_reduce_num = true; 148 int err; 149 150 if (!name) 151 return NULL; 152 153 if (index >= vdpa->nvqs) 154 return ERR_PTR(-ENOENT); 155 156 /* Queue shouldn't already be set up. */ 157 if (ops->get_vq_ready(vdpa, index)) 158 return ERR_PTR(-ENOENT); 159 160 /* Allocate and fill out our active queue description */ 161 info = kmalloc(sizeof(*info), GFP_KERNEL); 162 if (!info) 163 return ERR_PTR(-ENOMEM); 164 165 max_num = ops->get_vq_num_max(vdpa); 166 if (max_num == 0) { 167 err = -ENOENT; 168 goto error_new_virtqueue; 169 } 170 171 if (ops->get_vq_num_min) 172 min_num = ops->get_vq_num_min(vdpa); 173 174 may_reduce_num = (max_num == min_num) ? false : true; 175 176 /* Create the vring */ 177 align = ops->get_vq_align(vdpa); 178 vq = vring_create_virtqueue(index, max_num, align, vdev, 179 true, may_reduce_num, ctx, 180 virtio_vdpa_notify, callback, name); 181 if (!vq) { 182 err = -ENOMEM; 183 goto error_new_virtqueue; 184 } 185 186 vq->num_max = max_num; 187 188 /* Setup virtqueue callback */ 189 cb.callback = callback ? virtio_vdpa_virtqueue_cb : NULL; 190 cb.private = info; 191 ops->set_vq_cb(vdpa, index, &cb); 192 ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq)); 193 194 desc_addr = virtqueue_get_desc_addr(vq); 195 driver_addr = virtqueue_get_avail_addr(vq); 196 device_addr = virtqueue_get_used_addr(vq); 197 198 if (ops->set_vq_address(vdpa, index, 199 desc_addr, driver_addr, 200 device_addr)) { 201 err = -EINVAL; 202 goto err_vq; 203 } 204 205 /* reset virtqueue state index */ 206 if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) { 207 struct vdpa_vq_state_packed *s = &state.packed; 208 209 s->last_avail_counter = 1; 210 s->last_avail_idx = 0; 211 s->last_used_counter = 1; 212 s->last_used_idx = 0; 213 } 214 err = ops->set_vq_state(vdpa, index, &state); 215 if (err) 216 goto err_vq; 217 218 ops->set_vq_ready(vdpa, index, 1); 219 220 vq->priv = info; 221 info->vq = vq; 222 223 spin_lock_irqsave(&vd_dev->lock, flags); 224 list_add(&info->node, &vd_dev->virtqueues); 225 spin_unlock_irqrestore(&vd_dev->lock, flags); 226 227 return vq; 228 229 err_vq: 230 vring_del_virtqueue(vq); 231 error_new_virtqueue: 232 ops->set_vq_ready(vdpa, index, 0); 233 /* VDPA driver should make sure vq is stopeed here */ 234 WARN_ON(ops->get_vq_ready(vdpa, index)); 235 kfree(info); 236 return ERR_PTR(err); 237 } 238 239 static void virtio_vdpa_del_vq(struct virtqueue *vq) 240 { 241 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev); 242 struct vdpa_device *vdpa = vd_dev->vdpa; 243 const struct vdpa_config_ops *ops = vdpa->config; 244 struct virtio_vdpa_vq_info *info = vq->priv; 245 unsigned int index = vq->index; 246 unsigned long flags; 247 248 spin_lock_irqsave(&vd_dev->lock, flags); 249 list_del(&info->node); 250 spin_unlock_irqrestore(&vd_dev->lock, flags); 251 252 /* Select and deactivate the queue (best effort) */ 253 ops->set_vq_ready(vdpa, index, 0); 254 255 vring_del_virtqueue(vq); 256 257 kfree(info); 258 } 259 260 static void virtio_vdpa_del_vqs(struct virtio_device *vdev) 261 { 262 struct virtqueue *vq, *n; 263 264 list_for_each_entry_safe(vq, n, &vdev->vqs, list) 265 virtio_vdpa_del_vq(vq); 266 } 267 268 static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 269 struct virtqueue *vqs[], 270 vq_callback_t *callbacks[], 271 const char * const names[], 272 const bool *ctx, 273 struct irq_affinity *desc) 274 { 275 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 276 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 277 const struct vdpa_config_ops *ops = vdpa->config; 278 struct vdpa_callback cb; 279 int i, err, queue_idx = 0; 280 281 for (i = 0; i < nvqs; ++i) { 282 if (!names[i]) { 283 vqs[i] = NULL; 284 continue; 285 } 286 287 vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, 288 callbacks[i], names[i], ctx ? 289 ctx[i] : false); 290 if (IS_ERR(vqs[i])) { 291 err = PTR_ERR(vqs[i]); 292 goto err_setup_vq; 293 } 294 } 295 296 cb.callback = virtio_vdpa_config_cb; 297 cb.private = vd_dev; 298 ops->set_config_cb(vdpa, &cb); 299 300 return 0; 301 302 err_setup_vq: 303 virtio_vdpa_del_vqs(vdev); 304 return err; 305 } 306 307 static u64 virtio_vdpa_get_features(struct virtio_device *vdev) 308 { 309 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 310 const struct vdpa_config_ops *ops = vdpa->config; 311 312 return ops->get_device_features(vdpa); 313 } 314 315 static int virtio_vdpa_finalize_features(struct virtio_device *vdev) 316 { 317 struct vdpa_device *vdpa = vd_get_vdpa(vdev); 318 319 /* Give virtio_ring a chance to accept features. */ 320 vring_transport_features(vdev); 321 322 return vdpa_set_features(vdpa, vdev->features); 323 } 324 325 static const char *virtio_vdpa_bus_name(struct virtio_device *vdev) 326 { 327 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); 328 struct vdpa_device *vdpa = vd_dev->vdpa; 329 330 return dev_name(&vdpa->dev); 331 } 332 333 static const struct virtio_config_ops virtio_vdpa_config_ops = { 334 .get = virtio_vdpa_get, 335 .set = virtio_vdpa_set, 336 .generation = virtio_vdpa_generation, 337 .get_status = virtio_vdpa_get_status, 338 .set_status = virtio_vdpa_set_status, 339 .reset = virtio_vdpa_reset, 340 .find_vqs = virtio_vdpa_find_vqs, 341 .del_vqs = virtio_vdpa_del_vqs, 342 .get_features = virtio_vdpa_get_features, 343 .finalize_features = virtio_vdpa_finalize_features, 344 .bus_name = virtio_vdpa_bus_name, 345 }; 346 347 static void virtio_vdpa_release_dev(struct device *_d) 348 { 349 struct virtio_device *vdev = 350 container_of(_d, struct virtio_device, dev); 351 struct virtio_vdpa_device *vd_dev = 352 container_of(vdev, struct virtio_vdpa_device, vdev); 353 354 kfree(vd_dev); 355 } 356 357 static int virtio_vdpa_probe(struct vdpa_device *vdpa) 358 { 359 const struct vdpa_config_ops *ops = vdpa->config; 360 struct virtio_vdpa_device *vd_dev, *reg_dev = NULL; 361 int ret = -EINVAL; 362 363 vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL); 364 if (!vd_dev) 365 return -ENOMEM; 366 367 vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa); 368 vd_dev->vdev.dev.release = virtio_vdpa_release_dev; 369 vd_dev->vdev.config = &virtio_vdpa_config_ops; 370 vd_dev->vdpa = vdpa; 371 INIT_LIST_HEAD(&vd_dev->virtqueues); 372 spin_lock_init(&vd_dev->lock); 373 374 vd_dev->vdev.id.device = ops->get_device_id(vdpa); 375 if (vd_dev->vdev.id.device == 0) 376 goto err; 377 378 vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa); 379 ret = register_virtio_device(&vd_dev->vdev); 380 reg_dev = vd_dev; 381 if (ret) 382 goto err; 383 384 vdpa_set_drvdata(vdpa, vd_dev); 385 386 return 0; 387 388 err: 389 if (reg_dev) 390 put_device(&vd_dev->vdev.dev); 391 else 392 kfree(vd_dev); 393 return ret; 394 } 395 396 static void virtio_vdpa_remove(struct vdpa_device *vdpa) 397 { 398 struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa); 399 400 unregister_virtio_device(&vd_dev->vdev); 401 } 402 403 static struct vdpa_driver virtio_vdpa_driver = { 404 .driver = { 405 .name = "virtio_vdpa", 406 }, 407 .probe = virtio_vdpa_probe, 408 .remove = virtio_vdpa_remove, 409 }; 410 411 module_vdpa_driver(virtio_vdpa_driver); 412 413 MODULE_VERSION(MOD_VERSION); 414 MODULE_LICENSE(MOD_LICENSE); 415 MODULE_AUTHOR(MOD_AUTHOR); 416 MODULE_DESCRIPTION(MOD_DESC); 417