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c043b4a8 JW |
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); | |
c043b4a8 | 60 | |
63991673 | 61 | vdpa_get_config(vdpa, offset, buf, len); |
c043b4a8 JW |
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); | |
c043b4a8 | 103 | |
63991673 | 104 | vdpa_reset(vdpa); |
c043b4a8 JW |
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 | unsigned long flags; | |
146 | u32 align, num; | |
147 | int err; | |
148 | ||
149 | if (!name) | |
150 | return NULL; | |
151 | ||
152 | /* Queue shouldn't already be set up. */ | |
153 | if (ops->get_vq_ready(vdpa, index)) | |
154 | return ERR_PTR(-ENOENT); | |
155 | ||
156 | /* Allocate and fill out our active queue description */ | |
157 | info = kmalloc(sizeof(*info), GFP_KERNEL); | |
158 | if (!info) | |
159 | return ERR_PTR(-ENOMEM); | |
160 | ||
161 | num = ops->get_vq_num_max(vdpa); | |
162 | if (num == 0) { | |
163 | err = -ENOENT; | |
164 | goto error_new_virtqueue; | |
165 | } | |
166 | ||
167 | /* Create the vring */ | |
168 | align = ops->get_vq_align(vdpa); | |
169 | vq = vring_create_virtqueue(index, num, align, vdev, | |
170 | true, true, ctx, | |
171 | virtio_vdpa_notify, callback, name); | |
172 | if (!vq) { | |
173 | err = -ENOMEM; | |
174 | goto error_new_virtqueue; | |
175 | } | |
176 | ||
177 | /* Setup virtqueue callback */ | |
178 | cb.callback = virtio_vdpa_virtqueue_cb; | |
179 | cb.private = info; | |
180 | ops->set_vq_cb(vdpa, index, &cb); | |
181 | ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq)); | |
182 | ||
183 | desc_addr = virtqueue_get_desc_addr(vq); | |
184 | driver_addr = virtqueue_get_avail_addr(vq); | |
185 | device_addr = virtqueue_get_used_addr(vq); | |
186 | ||
187 | if (ops->set_vq_address(vdpa, index, | |
188 | desc_addr, driver_addr, | |
189 | device_addr)) { | |
190 | err = -EINVAL; | |
191 | goto err_vq; | |
192 | } | |
193 | ||
194 | ops->set_vq_ready(vdpa, index, 1); | |
195 | ||
196 | vq->priv = info; | |
197 | info->vq = vq; | |
198 | ||
199 | spin_lock_irqsave(&vd_dev->lock, flags); | |
200 | list_add(&info->node, &vd_dev->virtqueues); | |
201 | spin_unlock_irqrestore(&vd_dev->lock, flags); | |
202 | ||
203 | return vq; | |
204 | ||
205 | err_vq: | |
206 | vring_del_virtqueue(vq); | |
207 | error_new_virtqueue: | |
208 | ops->set_vq_ready(vdpa, index, 0); | |
209 | /* VDPA driver should make sure vq is stopeed here */ | |
210 | WARN_ON(ops->get_vq_ready(vdpa, index)); | |
211 | kfree(info); | |
212 | return ERR_PTR(err); | |
213 | } | |
214 | ||
215 | static void virtio_vdpa_del_vq(struct virtqueue *vq) | |
216 | { | |
217 | struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev); | |
218 | struct vdpa_device *vdpa = vd_dev->vdpa; | |
219 | const struct vdpa_config_ops *ops = vdpa->config; | |
220 | struct virtio_vdpa_vq_info *info = vq->priv; | |
221 | unsigned int index = vq->index; | |
222 | unsigned long flags; | |
223 | ||
224 | spin_lock_irqsave(&vd_dev->lock, flags); | |
225 | list_del(&info->node); | |
226 | spin_unlock_irqrestore(&vd_dev->lock, flags); | |
227 | ||
1628c687 | 228 | /* Select and deactivate the queue (best effort) */ |
c043b4a8 | 229 | ops->set_vq_ready(vdpa, index, 0); |
c043b4a8 JW |
230 | |
231 | vring_del_virtqueue(vq); | |
232 | ||
233 | kfree(info); | |
234 | } | |
235 | ||
236 | static void virtio_vdpa_del_vqs(struct virtio_device *vdev) | |
237 | { | |
238 | struct virtqueue *vq, *n; | |
239 | ||
240 | list_for_each_entry_safe(vq, n, &vdev->vqs, list) | |
241 | virtio_vdpa_del_vq(vq); | |
242 | } | |
243 | ||
244 | static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs, | |
245 | struct virtqueue *vqs[], | |
246 | vq_callback_t *callbacks[], | |
247 | const char * const names[], | |
248 | const bool *ctx, | |
249 | struct irq_affinity *desc) | |
250 | { | |
251 | struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); | |
252 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
253 | const struct vdpa_config_ops *ops = vdpa->config; | |
254 | struct vdpa_callback cb; | |
255 | int i, err, queue_idx = 0; | |
256 | ||
257 | for (i = 0; i < nvqs; ++i) { | |
258 | if (!names[i]) { | |
259 | vqs[i] = NULL; | |
260 | continue; | |
261 | } | |
262 | ||
263 | vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, | |
264 | callbacks[i], names[i], ctx ? | |
265 | ctx[i] : false); | |
266 | if (IS_ERR(vqs[i])) { | |
267 | err = PTR_ERR(vqs[i]); | |
268 | goto err_setup_vq; | |
269 | } | |
270 | } | |
271 | ||
272 | cb.callback = virtio_vdpa_config_cb; | |
273 | cb.private = vd_dev; | |
274 | ops->set_config_cb(vdpa, &cb); | |
275 | ||
276 | return 0; | |
277 | ||
278 | err_setup_vq: | |
279 | virtio_vdpa_del_vqs(vdev); | |
280 | return err; | |
281 | } | |
282 | ||
283 | static u64 virtio_vdpa_get_features(struct virtio_device *vdev) | |
284 | { | |
285 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
286 | const struct vdpa_config_ops *ops = vdpa->config; | |
287 | ||
288 | return ops->get_features(vdpa); | |
289 | } | |
290 | ||
291 | static int virtio_vdpa_finalize_features(struct virtio_device *vdev) | |
292 | { | |
293 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
c043b4a8 JW |
294 | |
295 | /* Give virtio_ring a chance to accept features. */ | |
296 | vring_transport_features(vdev); | |
297 | ||
63991673 | 298 | return vdpa_set_features(vdpa, vdev->features); |
c043b4a8 JW |
299 | } |
300 | ||
301 | static const char *virtio_vdpa_bus_name(struct virtio_device *vdev) | |
302 | { | |
303 | struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); | |
304 | struct vdpa_device *vdpa = vd_dev->vdpa; | |
305 | ||
306 | return dev_name(&vdpa->dev); | |
307 | } | |
308 | ||
309 | static const struct virtio_config_ops virtio_vdpa_config_ops = { | |
310 | .get = virtio_vdpa_get, | |
311 | .set = virtio_vdpa_set, | |
312 | .generation = virtio_vdpa_generation, | |
313 | .get_status = virtio_vdpa_get_status, | |
314 | .set_status = virtio_vdpa_set_status, | |
315 | .reset = virtio_vdpa_reset, | |
316 | .find_vqs = virtio_vdpa_find_vqs, | |
317 | .del_vqs = virtio_vdpa_del_vqs, | |
318 | .get_features = virtio_vdpa_get_features, | |
319 | .finalize_features = virtio_vdpa_finalize_features, | |
320 | .bus_name = virtio_vdpa_bus_name, | |
321 | }; | |
322 | ||
323 | static void virtio_vdpa_release_dev(struct device *_d) | |
324 | { | |
325 | struct virtio_device *vdev = | |
326 | container_of(_d, struct virtio_device, dev); | |
327 | struct virtio_vdpa_device *vd_dev = | |
328 | container_of(vdev, struct virtio_vdpa_device, vdev); | |
329 | ||
330 | kfree(vd_dev); | |
331 | } | |
332 | ||
333 | static int virtio_vdpa_probe(struct vdpa_device *vdpa) | |
334 | { | |
335 | const struct vdpa_config_ops *ops = vdpa->config; | |
336 | struct virtio_vdpa_device *vd_dev, *reg_dev = NULL; | |
337 | int ret = -EINVAL; | |
338 | ||
339 | vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL); | |
340 | if (!vd_dev) | |
341 | return -ENOMEM; | |
342 | ||
343 | vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa); | |
344 | vd_dev->vdev.dev.release = virtio_vdpa_release_dev; | |
345 | vd_dev->vdev.config = &virtio_vdpa_config_ops; | |
346 | vd_dev->vdpa = vdpa; | |
347 | INIT_LIST_HEAD(&vd_dev->virtqueues); | |
348 | spin_lock_init(&vd_dev->lock); | |
349 | ||
350 | vd_dev->vdev.id.device = ops->get_device_id(vdpa); | |
351 | if (vd_dev->vdev.id.device == 0) | |
352 | goto err; | |
353 | ||
354 | vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa); | |
355 | ret = register_virtio_device(&vd_dev->vdev); | |
356 | reg_dev = vd_dev; | |
357 | if (ret) | |
358 | goto err; | |
359 | ||
360 | vdpa_set_drvdata(vdpa, vd_dev); | |
361 | ||
362 | return 0; | |
363 | ||
364 | err: | |
365 | if (reg_dev) | |
366 | put_device(&vd_dev->vdev.dev); | |
367 | else | |
368 | kfree(vd_dev); | |
369 | return ret; | |
370 | } | |
371 | ||
372 | static void virtio_vdpa_remove(struct vdpa_device *vdpa) | |
373 | { | |
374 | struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa); | |
375 | ||
376 | unregister_virtio_device(&vd_dev->vdev); | |
377 | } | |
378 | ||
379 | static struct vdpa_driver virtio_vdpa_driver = { | |
380 | .driver = { | |
381 | .name = "virtio_vdpa", | |
382 | }, | |
383 | .probe = virtio_vdpa_probe, | |
384 | .remove = virtio_vdpa_remove, | |
385 | }; | |
386 | ||
387 | module_vdpa_driver(virtio_vdpa_driver); | |
388 | ||
389 | MODULE_VERSION(MOD_VERSION); | |
390 | MODULE_LICENSE(MOD_LICENSE); | |
391 | MODULE_AUTHOR(MOD_AUTHOR); | |
392 | MODULE_DESCRIPTION(MOD_DESC); |