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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 | ||
31532340 ST |
56 | static void virtio_vdpa_get(struct virtio_device *vdev, unsigned int offset, |
57 | void *buf, unsigned int len) | |
c043b4a8 JW |
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 | ||
31532340 ST |
64 | static void virtio_vdpa_set(struct virtio_device *vdev, unsigned int offset, |
65 | const void *buf, unsigned int len) | |
c043b4a8 JW |
66 | { |
67 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
c043b4a8 | 68 | |
6dbb1f16 | 69 | vdpa_set_config(vdpa, offset, buf, len); |
c043b4a8 JW |
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); | |
c043b4a8 | 94 | |
73bc0dbb | 95 | return vdpa_set_status(vdpa, status); |
c043b4a8 JW |
96 | } |
97 | ||
98 | static void virtio_vdpa_reset(struct virtio_device *vdev) | |
99 | { | |
100 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
c043b4a8 | 101 | |
63991673 | 102 | vdpa_reset(vdpa); |
c043b4a8 JW |
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; | |
efa08cb4 EC |
143 | /* Assume split virtqueue, switch to packed if necessary */ |
144 | struct vdpa_vq_state state = {0}; | |
c043b4a8 | 145 | unsigned long flags; |
30a03dfc WZ |
146 | u32 align, max_num, min_num = 1; |
147 | bool may_reduce_num = true; | |
c043b4a8 JW |
148 | int err; |
149 | ||
150 | if (!name) | |
151 | return NULL; | |
152 | ||
cb5d2c1f VW |
153 | if (index >= vdpa->nvqs) |
154 | return ERR_PTR(-ENOENT); | |
155 | ||
c043b4a8 JW |
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 | ||
30a03dfc WZ |
165 | max_num = ops->get_vq_num_max(vdpa); |
166 | if (max_num == 0) { | |
c043b4a8 JW |
167 | err = -ENOENT; |
168 | goto error_new_virtqueue; | |
169 | } | |
170 | ||
30a03dfc WZ |
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 | ||
c043b4a8 JW |
176 | /* Create the vring */ |
177 | align = ops->get_vq_align(vdpa); | |
30a03dfc WZ |
178 | vq = vring_create_virtqueue(index, max_num, align, vdev, |
179 | true, may_reduce_num, ctx, | |
c043b4a8 JW |
180 | virtio_vdpa_notify, callback, name); |
181 | if (!vq) { | |
182 | err = -ENOMEM; | |
183 | goto error_new_virtqueue; | |
184 | } | |
185 | ||
186 | /* Setup virtqueue callback */ | |
ea239a67 | 187 | cb.callback = callback ? virtio_vdpa_virtqueue_cb : NULL; |
c043b4a8 JW |
188 | cb.private = info; |
189 | ops->set_vq_cb(vdpa, index, &cb); | |
190 | ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq)); | |
191 | ||
192 | desc_addr = virtqueue_get_desc_addr(vq); | |
193 | driver_addr = virtqueue_get_avail_addr(vq); | |
194 | device_addr = virtqueue_get_used_addr(vq); | |
195 | ||
196 | if (ops->set_vq_address(vdpa, index, | |
197 | desc_addr, driver_addr, | |
198 | device_addr)) { | |
199 | err = -EINVAL; | |
200 | goto err_vq; | |
201 | } | |
202 | ||
efa08cb4 EC |
203 | /* reset virtqueue state index */ |
204 | if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) { | |
205 | struct vdpa_vq_state_packed *s = &state.packed; | |
206 | ||
207 | s->last_avail_counter = 1; | |
208 | s->last_avail_idx = 0; | |
209 | s->last_used_counter = 1; | |
210 | s->last_used_idx = 0; | |
211 | } | |
212 | err = ops->set_vq_state(vdpa, index, &state); | |
213 | if (err) | |
214 | goto err_vq; | |
215 | ||
c043b4a8 JW |
216 | ops->set_vq_ready(vdpa, index, 1); |
217 | ||
218 | vq->priv = info; | |
219 | info->vq = vq; | |
220 | ||
221 | spin_lock_irqsave(&vd_dev->lock, flags); | |
222 | list_add(&info->node, &vd_dev->virtqueues); | |
223 | spin_unlock_irqrestore(&vd_dev->lock, flags); | |
224 | ||
225 | return vq; | |
226 | ||
227 | err_vq: | |
228 | vring_del_virtqueue(vq); | |
229 | error_new_virtqueue: | |
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)); | |
233 | kfree(info); | |
234 | return ERR_PTR(err); | |
235 | } | |
236 | ||
237 | static void virtio_vdpa_del_vq(struct virtqueue *vq) | |
238 | { | |
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; | |
244 | unsigned long flags; | |
245 | ||
246 | spin_lock_irqsave(&vd_dev->lock, flags); | |
247 | list_del(&info->node); | |
248 | spin_unlock_irqrestore(&vd_dev->lock, flags); | |
249 | ||
1628c687 | 250 | /* Select and deactivate the queue (best effort) */ |
c043b4a8 | 251 | ops->set_vq_ready(vdpa, index, 0); |
c043b4a8 JW |
252 | |
253 | vring_del_virtqueue(vq); | |
254 | ||
255 | kfree(info); | |
256 | } | |
257 | ||
258 | static void virtio_vdpa_del_vqs(struct virtio_device *vdev) | |
259 | { | |
260 | struct virtqueue *vq, *n; | |
261 | ||
262 | list_for_each_entry_safe(vq, n, &vdev->vqs, list) | |
263 | virtio_vdpa_del_vq(vq); | |
264 | } | |
265 | ||
31532340 | 266 | static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs, |
c043b4a8 JW |
267 | struct virtqueue *vqs[], |
268 | vq_callback_t *callbacks[], | |
269 | const char * const names[], | |
270 | const bool *ctx, | |
271 | struct irq_affinity *desc) | |
272 | { | |
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; | |
278 | ||
279 | for (i = 0; i < nvqs; ++i) { | |
280 | if (!names[i]) { | |
281 | vqs[i] = NULL; | |
282 | continue; | |
283 | } | |
284 | ||
285 | vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, | |
286 | callbacks[i], names[i], ctx ? | |
287 | ctx[i] : false); | |
288 | if (IS_ERR(vqs[i])) { | |
289 | err = PTR_ERR(vqs[i]); | |
290 | goto err_setup_vq; | |
291 | } | |
292 | } | |
293 | ||
294 | cb.callback = virtio_vdpa_config_cb; | |
295 | cb.private = vd_dev; | |
296 | ops->set_config_cb(vdpa, &cb); | |
297 | ||
298 | return 0; | |
299 | ||
300 | err_setup_vq: | |
301 | virtio_vdpa_del_vqs(vdev); | |
302 | return err; | |
303 | } | |
304 | ||
305 | static u64 virtio_vdpa_get_features(struct virtio_device *vdev) | |
306 | { | |
307 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
308 | const struct vdpa_config_ops *ops = vdpa->config; | |
309 | ||
a64917bc | 310 | return ops->get_device_features(vdpa); |
c043b4a8 JW |
311 | } |
312 | ||
313 | static int virtio_vdpa_finalize_features(struct virtio_device *vdev) | |
314 | { | |
315 | struct vdpa_device *vdpa = vd_get_vdpa(vdev); | |
c043b4a8 JW |
316 | |
317 | /* Give virtio_ring a chance to accept features. */ | |
318 | vring_transport_features(vdev); | |
319 | ||
e0077cc1 | 320 | return vdpa_set_features(vdpa, vdev->features); |
c043b4a8 JW |
321 | } |
322 | ||
323 | static const char *virtio_vdpa_bus_name(struct virtio_device *vdev) | |
324 | { | |
325 | struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); | |
326 | struct vdpa_device *vdpa = vd_dev->vdpa; | |
327 | ||
328 | return dev_name(&vdpa->dev); | |
329 | } | |
330 | ||
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, | |
343 | }; | |
344 | ||
345 | static void virtio_vdpa_release_dev(struct device *_d) | |
346 | { | |
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); | |
351 | ||
352 | kfree(vd_dev); | |
353 | } | |
354 | ||
355 | static int virtio_vdpa_probe(struct vdpa_device *vdpa) | |
356 | { | |
357 | const struct vdpa_config_ops *ops = vdpa->config; | |
358 | struct virtio_vdpa_device *vd_dev, *reg_dev = NULL; | |
359 | int ret = -EINVAL; | |
360 | ||
361 | vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL); | |
362 | if (!vd_dev) | |
363 | return -ENOMEM; | |
364 | ||
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; | |
368 | vd_dev->vdpa = vdpa; | |
369 | INIT_LIST_HEAD(&vd_dev->virtqueues); | |
370 | spin_lock_init(&vd_dev->lock); | |
371 | ||
372 | vd_dev->vdev.id.device = ops->get_device_id(vdpa); | |
373 | if (vd_dev->vdev.id.device == 0) | |
374 | goto err; | |
375 | ||
376 | vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa); | |
377 | ret = register_virtio_device(&vd_dev->vdev); | |
378 | reg_dev = vd_dev; | |
379 | if (ret) | |
380 | goto err; | |
381 | ||
382 | vdpa_set_drvdata(vdpa, vd_dev); | |
383 | ||
384 | return 0; | |
385 | ||
386 | err: | |
387 | if (reg_dev) | |
388 | put_device(&vd_dev->vdev.dev); | |
389 | else | |
390 | kfree(vd_dev); | |
391 | return ret; | |
392 | } | |
393 | ||
394 | static void virtio_vdpa_remove(struct vdpa_device *vdpa) | |
395 | { | |
396 | struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa); | |
397 | ||
398 | unregister_virtio_device(&vd_dev->vdev); | |
399 | } | |
400 | ||
401 | static struct vdpa_driver virtio_vdpa_driver = { | |
402 | .driver = { | |
403 | .name = "virtio_vdpa", | |
404 | }, | |
405 | .probe = virtio_vdpa_probe, | |
406 | .remove = virtio_vdpa_remove, | |
407 | }; | |
408 | ||
409 | module_vdpa_driver(virtio_vdpa_driver); | |
410 | ||
411 | MODULE_VERSION(MOD_VERSION); | |
412 | MODULE_LICENSE(MOD_LICENSE); | |
413 | MODULE_AUTHOR(MOD_AUTHOR); | |
414 | MODULE_DESCRIPTION(MOD_DESC); |