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 offset,
57 void *buf, unsigned 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 offset,
65 const void *buf, unsigned len)
67 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
68 const struct vdpa_config_ops *ops = vdpa->config;
70 ops->set_config(vdpa, offset, buf, len);
73 static u32 virtio_vdpa_generation(struct virtio_device *vdev)
75 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
76 const struct vdpa_config_ops *ops = vdpa->config;
78 if (ops->get_generation)
79 return ops->get_generation(vdpa);
84 static u8 virtio_vdpa_get_status(struct virtio_device *vdev)
86 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
87 const struct vdpa_config_ops *ops = vdpa->config;
89 return ops->get_status(vdpa);
92 static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status)
94 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
95 const struct vdpa_config_ops *ops = vdpa->config;
97 return ops->set_status(vdpa, status);
100 static void virtio_vdpa_reset(struct virtio_device *vdev)
102 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
107 static bool virtio_vdpa_notify(struct virtqueue *vq)
109 struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev);
110 const struct vdpa_config_ops *ops = vdpa->config;
112 ops->kick_vq(vdpa, vq->index);
117 static irqreturn_t virtio_vdpa_config_cb(void *private)
119 struct virtio_vdpa_device *vd_dev = private;
121 virtio_config_changed(&vd_dev->vdev);
126 static irqreturn_t virtio_vdpa_virtqueue_cb(void *private)
128 struct virtio_vdpa_vq_info *info = private;
130 return vring_interrupt(0, info->vq);
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)
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;
152 if (index >= vdpa->nvqs)
153 return ERR_PTR(-ENOENT);
155 /* Queue shouldn't already be set up. */
156 if (ops->get_vq_ready(vdpa, index))
157 return ERR_PTR(-ENOENT);
159 /* Allocate and fill out our active queue description */
160 info = kmalloc(sizeof(*info), GFP_KERNEL);
162 return ERR_PTR(-ENOMEM);
164 num = ops->get_vq_num_max(vdpa);
167 goto error_new_virtqueue;
170 /* Create the vring */
171 align = ops->get_vq_align(vdpa);
172 vq = vring_create_virtqueue(index, num, align, vdev,
174 virtio_vdpa_notify, callback, name);
177 goto error_new_virtqueue;
180 /* Setup virtqueue callback */
181 cb.callback = virtio_vdpa_virtqueue_cb;
183 ops->set_vq_cb(vdpa, index, &cb);
184 ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
186 desc_addr = virtqueue_get_desc_addr(vq);
187 driver_addr = virtqueue_get_avail_addr(vq);
188 device_addr = virtqueue_get_used_addr(vq);
190 if (ops->set_vq_address(vdpa, index,
191 desc_addr, driver_addr,
197 ops->set_vq_ready(vdpa, index, 1);
202 spin_lock_irqsave(&vd_dev->lock, flags);
203 list_add(&info->node, &vd_dev->virtqueues);
204 spin_unlock_irqrestore(&vd_dev->lock, flags);
209 vring_del_virtqueue(vq);
211 ops->set_vq_ready(vdpa, index, 0);
212 /* VDPA driver should make sure vq is stopeed here */
213 WARN_ON(ops->get_vq_ready(vdpa, index));
218 static void virtio_vdpa_del_vq(struct virtqueue *vq)
220 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev);
221 struct vdpa_device *vdpa = vd_dev->vdpa;
222 const struct vdpa_config_ops *ops = vdpa->config;
223 struct virtio_vdpa_vq_info *info = vq->priv;
224 unsigned int index = vq->index;
227 spin_lock_irqsave(&vd_dev->lock, flags);
228 list_del(&info->node);
229 spin_unlock_irqrestore(&vd_dev->lock, flags);
231 /* Select and deactivate the queue */
232 ops->set_vq_ready(vdpa, index, 0);
233 WARN_ON(ops->get_vq_ready(vdpa, index));
235 vring_del_virtqueue(vq);
240 static void virtio_vdpa_del_vqs(struct virtio_device *vdev)
242 struct virtqueue *vq, *n;
244 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
245 virtio_vdpa_del_vq(vq);
248 static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs,
249 struct virtqueue *vqs[],
250 vq_callback_t *callbacks[],
251 const char * const names[],
253 struct irq_affinity *desc)
255 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
256 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
257 const struct vdpa_config_ops *ops = vdpa->config;
258 struct vdpa_callback cb;
259 int i, err, queue_idx = 0;
261 for (i = 0; i < nvqs; ++i) {
267 vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++,
268 callbacks[i], names[i], ctx ?
270 if (IS_ERR(vqs[i])) {
271 err = PTR_ERR(vqs[i]);
276 cb.callback = virtio_vdpa_config_cb;
278 ops->set_config_cb(vdpa, &cb);
283 virtio_vdpa_del_vqs(vdev);
287 static u64 virtio_vdpa_get_features(struct virtio_device *vdev)
289 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
290 const struct vdpa_config_ops *ops = vdpa->config;
292 return ops->get_features(vdpa);
295 static int virtio_vdpa_finalize_features(struct virtio_device *vdev)
297 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
299 /* Give virtio_ring a chance to accept features. */
300 vring_transport_features(vdev);
302 return vdpa_set_features(vdpa, vdev->features);
305 static const char *virtio_vdpa_bus_name(struct virtio_device *vdev)
307 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
308 struct vdpa_device *vdpa = vd_dev->vdpa;
310 return dev_name(&vdpa->dev);
313 static const struct virtio_config_ops virtio_vdpa_config_ops = {
314 .get = virtio_vdpa_get,
315 .set = virtio_vdpa_set,
316 .generation = virtio_vdpa_generation,
317 .get_status = virtio_vdpa_get_status,
318 .set_status = virtio_vdpa_set_status,
319 .reset = virtio_vdpa_reset,
320 .find_vqs = virtio_vdpa_find_vqs,
321 .del_vqs = virtio_vdpa_del_vqs,
322 .get_features = virtio_vdpa_get_features,
323 .finalize_features = virtio_vdpa_finalize_features,
324 .bus_name = virtio_vdpa_bus_name,
327 static void virtio_vdpa_release_dev(struct device *_d)
329 struct virtio_device *vdev =
330 container_of(_d, struct virtio_device, dev);
331 struct virtio_vdpa_device *vd_dev =
332 container_of(vdev, struct virtio_vdpa_device, vdev);
337 static int virtio_vdpa_probe(struct vdpa_device *vdpa)
339 const struct vdpa_config_ops *ops = vdpa->config;
340 struct virtio_vdpa_device *vd_dev, *reg_dev = NULL;
343 vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL);
347 vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa);
348 vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
349 vd_dev->vdev.config = &virtio_vdpa_config_ops;
351 INIT_LIST_HEAD(&vd_dev->virtqueues);
352 spin_lock_init(&vd_dev->lock);
354 vd_dev->vdev.id.device = ops->get_device_id(vdpa);
355 if (vd_dev->vdev.id.device == 0)
358 vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa);
359 ret = register_virtio_device(&vd_dev->vdev);
364 vdpa_set_drvdata(vdpa, vd_dev);
370 put_device(&vd_dev->vdev.dev);
376 static void virtio_vdpa_remove(struct vdpa_device *vdpa)
378 struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa);
380 unregister_virtio_device(&vd_dev->vdev);
383 static struct vdpa_driver virtio_vdpa_driver = {
385 .name = "virtio_vdpa",
387 .probe = virtio_vdpa_probe,
388 .remove = virtio_vdpa_remove,
391 module_vdpa_driver(virtio_vdpa_driver);
393 MODULE_VERSION(MOD_VERSION);
394 MODULE_LICENSE(MOD_LICENSE);
395 MODULE_AUTHOR(MOD_AUTHOR);
396 MODULE_DESCRIPTION(MOD_DESC);