1 // SPDX-License-Identifier: GPL-2.0-only
3 * VIRTIO based driver for vDPA device
5 * Copyright (c) 2020, Red Hat. All rights reserved.
6 * Author: Jason Wang <jasowang@redhat.com>
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>
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"
26 struct virtio_vdpa_device {
27 struct virtio_device vdev;
28 struct vdpa_device *vdpa;
31 /* The lock to protect virtqueue list */
33 /* List of virtio_vdpa_vq_info */
34 struct list_head virtqueues;
37 struct virtio_vdpa_vq_info {
38 /* the actual virtqueue */
41 /* the list node for the virtqueues list */
42 struct list_head node;
45 static inline struct virtio_vdpa_device *
46 to_virtio_vdpa_device(struct virtio_device *dev)
48 return container_of(dev, struct virtio_vdpa_device, vdev);
51 static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev)
53 return to_virtio_vdpa_device(vdev)->vdpa;
56 static void virtio_vdpa_get(struct virtio_device *vdev, unsigned int offset,
57 void *buf, unsigned int len)
59 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
61 vdpa_get_config(vdpa, offset, buf, len);
64 static void virtio_vdpa_set(struct virtio_device *vdev, unsigned int offset,
65 const void *buf, unsigned int len)
67 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
69 vdpa_set_config(vdpa, offset, buf, len);
72 static u32 virtio_vdpa_generation(struct virtio_device *vdev)
74 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
75 const struct vdpa_config_ops *ops = vdpa->config;
77 if (ops->get_generation)
78 return ops->get_generation(vdpa);
83 static u8 virtio_vdpa_get_status(struct virtio_device *vdev)
85 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
86 const struct vdpa_config_ops *ops = vdpa->config;
88 return ops->get_status(vdpa);
91 static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status)
93 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
95 return vdpa_set_status(vdpa, status);
98 static void virtio_vdpa_reset(struct virtio_device *vdev)
100 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
105 static bool virtio_vdpa_notify(struct virtqueue *vq)
107 struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev);
108 const struct vdpa_config_ops *ops = vdpa->config;
110 ops->kick_vq(vdpa, vq->index);
115 static irqreturn_t virtio_vdpa_config_cb(void *private)
117 struct virtio_vdpa_device *vd_dev = private;
119 virtio_config_changed(&vd_dev->vdev);
124 static irqreturn_t virtio_vdpa_virtqueue_cb(void *private)
126 struct virtio_vdpa_vq_info *info = private;
128 return vring_interrupt(0, info->vq);
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, u32 size, bool ctx)
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};
146 u32 align, max_num, min_num = 1;
147 bool may_reduce_num = true;
153 if (index >= vdpa->nvqs)
154 return ERR_PTR(-ENOENT);
156 /* Queue shouldn't already be set up. */
157 if (ops->get_vq_ready(vdpa, index))
158 return ERR_PTR(-ENOENT);
160 /* Allocate and fill out our active queue description */
161 info = kmalloc(sizeof(*info), GFP_KERNEL);
163 return ERR_PTR(-ENOMEM);
165 max_num = ops->get_vq_num_max(vdpa);
168 goto error_new_virtqueue;
171 if (!size || size > max_num)
174 if (ops->get_vq_num_min)
175 min_num = ops->get_vq_num_min(vdpa);
177 may_reduce_num = (size == min_num) ? false : true;
179 /* Create the vring */
180 align = ops->get_vq_align(vdpa);
181 vq = vring_create_virtqueue(index, size, align, vdev,
182 true, may_reduce_num, ctx,
183 virtio_vdpa_notify, callback, name);
186 goto error_new_virtqueue;
189 vq->num_max = max_num;
191 /* Setup virtqueue callback */
192 cb.callback = callback ? virtio_vdpa_virtqueue_cb : NULL;
194 ops->set_vq_cb(vdpa, index, &cb);
195 ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
197 desc_addr = virtqueue_get_desc_addr(vq);
198 driver_addr = virtqueue_get_avail_addr(vq);
199 device_addr = virtqueue_get_used_addr(vq);
201 if (ops->set_vq_address(vdpa, index,
202 desc_addr, driver_addr,
208 /* reset virtqueue state index */
209 if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
210 struct vdpa_vq_state_packed *s = &state.packed;
212 s->last_avail_counter = 1;
213 s->last_avail_idx = 0;
214 s->last_used_counter = 1;
215 s->last_used_idx = 0;
217 err = ops->set_vq_state(vdpa, index, &state);
221 ops->set_vq_ready(vdpa, index, 1);
226 spin_lock_irqsave(&vd_dev->lock, flags);
227 list_add(&info->node, &vd_dev->virtqueues);
228 spin_unlock_irqrestore(&vd_dev->lock, flags);
233 vring_del_virtqueue(vq);
235 ops->set_vq_ready(vdpa, index, 0);
236 /* VDPA driver should make sure vq is stopeed here */
237 WARN_ON(ops->get_vq_ready(vdpa, index));
242 static void virtio_vdpa_del_vq(struct virtqueue *vq)
244 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev);
245 struct vdpa_device *vdpa = vd_dev->vdpa;
246 const struct vdpa_config_ops *ops = vdpa->config;
247 struct virtio_vdpa_vq_info *info = vq->priv;
248 unsigned int index = vq->index;
251 spin_lock_irqsave(&vd_dev->lock, flags);
252 list_del(&info->node);
253 spin_unlock_irqrestore(&vd_dev->lock, flags);
255 /* Select and deactivate the queue (best effort) */
256 ops->set_vq_ready(vdpa, index, 0);
258 vring_del_virtqueue(vq);
263 static void virtio_vdpa_del_vqs(struct virtio_device *vdev)
265 struct virtqueue *vq, *n;
267 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
268 virtio_vdpa_del_vq(vq);
271 static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
272 struct virtqueue *vqs[],
273 vq_callback_t *callbacks[],
274 const char * const names[],
277 struct irq_affinity *desc)
279 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
280 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
281 const struct vdpa_config_ops *ops = vdpa->config;
282 struct vdpa_callback cb;
283 int i, err, queue_idx = 0;
285 for (i = 0; i < nvqs; ++i) {
291 vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, callbacks[i],
292 names[i], sizes ? sizes[i] : 0,
293 ctx ? ctx[i] : false);
294 if (IS_ERR(vqs[i])) {
295 err = PTR_ERR(vqs[i]);
300 cb.callback = virtio_vdpa_config_cb;
302 ops->set_config_cb(vdpa, &cb);
307 virtio_vdpa_del_vqs(vdev);
311 static u64 virtio_vdpa_get_features(struct virtio_device *vdev)
313 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
314 const struct vdpa_config_ops *ops = vdpa->config;
316 return ops->get_device_features(vdpa);
319 static int virtio_vdpa_finalize_features(struct virtio_device *vdev)
321 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
323 /* Give virtio_ring a chance to accept features. */
324 vring_transport_features(vdev);
326 return vdpa_set_features(vdpa, vdev->features);
329 static const char *virtio_vdpa_bus_name(struct virtio_device *vdev)
331 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
332 struct vdpa_device *vdpa = vd_dev->vdpa;
334 return dev_name(&vdpa->dev);
337 static const struct virtio_config_ops virtio_vdpa_config_ops = {
338 .get = virtio_vdpa_get,
339 .set = virtio_vdpa_set,
340 .generation = virtio_vdpa_generation,
341 .get_status = virtio_vdpa_get_status,
342 .set_status = virtio_vdpa_set_status,
343 .reset = virtio_vdpa_reset,
344 .find_vqs = virtio_vdpa_find_vqs,
345 .del_vqs = virtio_vdpa_del_vqs,
346 .get_features = virtio_vdpa_get_features,
347 .finalize_features = virtio_vdpa_finalize_features,
348 .bus_name = virtio_vdpa_bus_name,
351 static void virtio_vdpa_release_dev(struct device *_d)
353 struct virtio_device *vdev =
354 container_of(_d, struct virtio_device, dev);
355 struct virtio_vdpa_device *vd_dev =
356 container_of(vdev, struct virtio_vdpa_device, vdev);
361 static int virtio_vdpa_probe(struct vdpa_device *vdpa)
363 const struct vdpa_config_ops *ops = vdpa->config;
364 struct virtio_vdpa_device *vd_dev, *reg_dev = NULL;
367 vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL);
371 vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa);
372 vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
373 vd_dev->vdev.config = &virtio_vdpa_config_ops;
375 INIT_LIST_HEAD(&vd_dev->virtqueues);
376 spin_lock_init(&vd_dev->lock);
378 vd_dev->vdev.id.device = ops->get_device_id(vdpa);
379 if (vd_dev->vdev.id.device == 0)
382 vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa);
383 ret = register_virtio_device(&vd_dev->vdev);
388 vdpa_set_drvdata(vdpa, vd_dev);
394 put_device(&vd_dev->vdev.dev);
400 static void virtio_vdpa_remove(struct vdpa_device *vdpa)
402 struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa);
404 unregister_virtio_device(&vd_dev->vdev);
407 static struct vdpa_driver virtio_vdpa_driver = {
409 .name = "virtio_vdpa",
411 .probe = virtio_vdpa_probe,
412 .remove = virtio_vdpa_remove,
415 module_vdpa_driver(virtio_vdpa_driver);
417 MODULE_VERSION(MOD_VERSION);
418 MODULE_LICENSE(MOD_LICENSE);
419 MODULE_AUTHOR(MOD_AUTHOR);
420 MODULE_DESCRIPTION(MOD_DESC);