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);
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, 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 (ops->get_vq_num_min)
172 min_num = ops->get_vq_num_min(vdpa);
174 may_reduce_num = (max_num == min_num) ? false : true;
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);
183 goto error_new_virtqueue;
186 /* Setup virtqueue callback */
187 cb.callback = virtio_vdpa_virtqueue_cb;
189 ops->set_vq_cb(vdpa, index, &cb);
190 ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq));
192 desc_addr = virtqueue_get_desc_addr(vq);
193 driver_addr = virtqueue_get_avail_addr(vq);
194 device_addr = virtqueue_get_used_addr(vq);
196 if (ops->set_vq_address(vdpa, index,
197 desc_addr, driver_addr,
203 /* reset virtqueue state index */
204 if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
205 struct vdpa_vq_state_packed *s = &state.packed;
207 s->last_avail_counter = 1;
208 s->last_avail_idx = 0;
209 s->last_used_counter = 1;
210 s->last_used_idx = 0;
212 err = ops->set_vq_state(vdpa, index, &state);
216 ops->set_vq_ready(vdpa, index, 1);
221 spin_lock_irqsave(&vd_dev->lock, flags);
222 list_add(&info->node, &vd_dev->virtqueues);
223 spin_unlock_irqrestore(&vd_dev->lock, flags);
228 vring_del_virtqueue(vq);
230 ops->set_vq_ready(vdpa, index, 0);
231 /* VDPA driver should make sure vq is stopeed here */
232 WARN_ON(ops->get_vq_ready(vdpa, index));
237 static void virtio_vdpa_del_vq(struct virtqueue *vq)
239 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev);
240 struct vdpa_device *vdpa = vd_dev->vdpa;
241 const struct vdpa_config_ops *ops = vdpa->config;
242 struct virtio_vdpa_vq_info *info = vq->priv;
243 unsigned int index = vq->index;
246 spin_lock_irqsave(&vd_dev->lock, flags);
247 list_del(&info->node);
248 spin_unlock_irqrestore(&vd_dev->lock, flags);
250 /* Select and deactivate the queue (best effort) */
251 ops->set_vq_ready(vdpa, index, 0);
253 vring_del_virtqueue(vq);
258 static void virtio_vdpa_del_vqs(struct virtio_device *vdev)
260 struct virtqueue *vq, *n;
262 list_for_each_entry_safe(vq, n, &vdev->vqs, list)
263 virtio_vdpa_del_vq(vq);
266 static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs,
267 struct virtqueue *vqs[],
268 vq_callback_t *callbacks[],
269 const char * const names[],
271 struct irq_affinity *desc)
273 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
274 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
275 const struct vdpa_config_ops *ops = vdpa->config;
276 struct vdpa_callback cb;
277 int i, err, queue_idx = 0;
279 for (i = 0; i < nvqs; ++i) {
285 vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++,
286 callbacks[i], names[i], ctx ?
288 if (IS_ERR(vqs[i])) {
289 err = PTR_ERR(vqs[i]);
294 cb.callback = virtio_vdpa_config_cb;
296 ops->set_config_cb(vdpa, &cb);
301 virtio_vdpa_del_vqs(vdev);
305 static u64 virtio_vdpa_get_features(struct virtio_device *vdev)
307 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
308 const struct vdpa_config_ops *ops = vdpa->config;
310 return ops->get_device_features(vdpa);
313 static int virtio_vdpa_finalize_features(struct virtio_device *vdev)
315 struct vdpa_device *vdpa = vd_get_vdpa(vdev);
317 /* Give virtio_ring a chance to accept features. */
318 vring_transport_features(vdev);
320 return vdpa_set_features(vdpa, vdev->features, false);
323 static const char *virtio_vdpa_bus_name(struct virtio_device *vdev)
325 struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev);
326 struct vdpa_device *vdpa = vd_dev->vdpa;
328 return dev_name(&vdpa->dev);
331 static const struct virtio_config_ops virtio_vdpa_config_ops = {
332 .get = virtio_vdpa_get,
333 .set = virtio_vdpa_set,
334 .generation = virtio_vdpa_generation,
335 .get_status = virtio_vdpa_get_status,
336 .set_status = virtio_vdpa_set_status,
337 .reset = virtio_vdpa_reset,
338 .find_vqs = virtio_vdpa_find_vqs,
339 .del_vqs = virtio_vdpa_del_vqs,
340 .get_features = virtio_vdpa_get_features,
341 .finalize_features = virtio_vdpa_finalize_features,
342 .bus_name = virtio_vdpa_bus_name,
345 static void virtio_vdpa_release_dev(struct device *_d)
347 struct virtio_device *vdev =
348 container_of(_d, struct virtio_device, dev);
349 struct virtio_vdpa_device *vd_dev =
350 container_of(vdev, struct virtio_vdpa_device, vdev);
355 static int virtio_vdpa_probe(struct vdpa_device *vdpa)
357 const struct vdpa_config_ops *ops = vdpa->config;
358 struct virtio_vdpa_device *vd_dev, *reg_dev = NULL;
361 vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL);
365 vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa);
366 vd_dev->vdev.dev.release = virtio_vdpa_release_dev;
367 vd_dev->vdev.config = &virtio_vdpa_config_ops;
369 INIT_LIST_HEAD(&vd_dev->virtqueues);
370 spin_lock_init(&vd_dev->lock);
372 vd_dev->vdev.id.device = ops->get_device_id(vdpa);
373 if (vd_dev->vdev.id.device == 0)
376 vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa);
377 ret = register_virtio_device(&vd_dev->vdev);
382 vdpa_set_drvdata(vdpa, vd_dev);
388 put_device(&vd_dev->vdev.dev);
394 static void virtio_vdpa_remove(struct vdpa_device *vdpa)
396 struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa);
398 unregister_virtio_device(&vd_dev->vdev);
401 static struct vdpa_driver virtio_vdpa_driver = {
403 .name = "virtio_vdpa",
405 .probe = virtio_vdpa_probe,
406 .remove = virtio_vdpa_remove,
409 module_vdpa_driver(virtio_vdpa_driver);
411 MODULE_VERSION(MOD_VERSION);
412 MODULE_LICENSE(MOD_LICENSE);
413 MODULE_AUTHOR(MOD_AUTHOR);
414 MODULE_DESCRIPTION(MOD_DESC);