1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
4 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
6 * VirtIO is a virtualization standard for network and disk device drivers
7 * where just the guest's device driver "knows" it is running in a virtual
8 * environment, and cooperates with the hypervisor. This enables guests to
9 * get high performance network and disk operations, and gives most of the
10 * performance benefits of paravirtualization. In the U-Boot case, the guest
11 * is U-Boot itself, while the virtual environment are normally QEMU targets
12 * like ARM, RISC-V and x86.
14 * See http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.pdf for
15 * the VirtIO specification v1.0.
22 #include <virtio_types.h>
25 #include <linux/bug.h>
27 static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
28 [VIRTIO_ID_NET] = VIRTIO_NET_DRV_NAME,
29 [VIRTIO_ID_BLOCK] = VIRTIO_BLK_DRV_NAME,
30 [VIRTIO_ID_RNG] = VIRTIO_RNG_DRV_NAME,
33 int virtio_get_config(struct udevice *vdev, unsigned int offset,
34 void *buf, unsigned int len)
36 struct dm_virtio_ops *ops;
38 ops = virtio_get_ops(vdev->parent);
40 return ops->get_config(vdev->parent, offset, buf, len);
43 int virtio_set_config(struct udevice *vdev, unsigned int offset,
44 void *buf, unsigned int len)
46 struct dm_virtio_ops *ops;
48 ops = virtio_get_ops(vdev->parent);
50 return ops->set_config(vdev->parent, offset, buf, len);
53 int virtio_generation(struct udevice *vdev, u32 *counter)
55 struct dm_virtio_ops *ops;
57 ops = virtio_get_ops(vdev->parent);
61 return ops->generation(vdev->parent, counter);
64 int virtio_get_status(struct udevice *vdev, u8 *status)
66 struct dm_virtio_ops *ops;
68 ops = virtio_get_ops(vdev->parent);
70 return ops->get_status(vdev->parent, status);
73 int virtio_set_status(struct udevice *vdev, u8 status)
75 struct dm_virtio_ops *ops;
77 ops = virtio_get_ops(vdev->parent);
79 return ops->set_status(vdev->parent, status);
82 int virtio_reset(struct udevice *vdev)
84 struct dm_virtio_ops *ops;
86 ops = virtio_get_ops(vdev->parent);
88 return ops->reset(vdev->parent);
91 int virtio_get_features(struct udevice *vdev, u64 *features)
93 struct dm_virtio_ops *ops;
95 ops = virtio_get_ops(vdev->parent);
97 return ops->get_features(vdev->parent, features);
100 int virtio_set_features(struct udevice *vdev)
102 struct dm_virtio_ops *ops;
104 ops = virtio_get_ops(vdev->parent);
106 return ops->set_features(vdev->parent);
109 int virtio_find_vqs(struct udevice *vdev, unsigned int nvqs,
110 struct virtqueue *vqs[])
112 struct dm_virtio_ops *ops;
114 ops = virtio_get_ops(vdev->parent);
116 return ops->find_vqs(vdev->parent, nvqs, vqs);
119 int virtio_del_vqs(struct udevice *vdev)
121 struct dm_virtio_ops *ops;
123 ops = virtio_get_ops(vdev->parent);
125 return ops->del_vqs(vdev->parent);
128 int virtio_notify(struct udevice *vdev, struct virtqueue *vq)
130 struct dm_virtio_ops *ops;
132 ops = virtio_get_ops(vdev->parent);
134 return ops->notify(vdev->parent, vq);
137 void virtio_add_status(struct udevice *vdev, u8 status)
141 if (!virtio_get_status(vdev, &old))
142 virtio_set_status(vdev, old | status);
145 int virtio_finalize_features(struct udevice *vdev)
147 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
151 ret = virtio_set_features(vdev);
158 virtio_add_status(vdev, VIRTIO_CONFIG_S_FEATURES_OK);
159 ret = virtio_get_status(vdev, &status);
162 if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
163 debug("(%s): device refuses features %x\n", vdev->name, status);
170 void virtio_driver_features_init(struct virtio_dev_priv *priv,
173 const u32 *feature_legacy,
174 u32 feature_legacy_size)
176 priv->feature_table = feature;
177 priv->feature_table_size = feature_size;
178 priv->feature_table_legacy = feature_legacy;
179 priv->feature_table_size_legacy = feature_legacy_size;
182 int virtio_init(void)
187 /* Enumerate all known virtio devices */
188 ret = uclass_first_device(UCLASS_VIRTIO, &bus);
193 ret = uclass_next_device(&bus);
201 static int virtio_uclass_pre_probe(struct udevice *udev)
203 struct dm_virtio_ops *ops;
205 ops = (struct dm_virtio_ops *)(udev->driver->ops);
208 * Check virtio transport driver ops here so that we don't need
209 * check these ops each time when the virtio_xxx APIs are called.
211 * Only generation op is optional. All other ops are must-have.
213 if (!ops->get_config || !ops->set_config ||
214 !ops->get_status || !ops->set_status ||
215 !ops->get_features || !ops->set_features ||
216 !ops->find_vqs || !ops->del_vqs ||
217 !ops->reset || !ops->notify)
223 static int virtio_uclass_post_probe(struct udevice *udev)
225 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
226 char dev_name[30], *str;
227 struct udevice *vdev;
230 if (uc_priv->device > VIRTIO_ID_MAX_NUM) {
231 debug("(%s): virtio device ID %d exceeds maximum num\n",
232 udev->name, uc_priv->device);
236 if (!virtio_drv_name[uc_priv->device]) {
237 debug("(%s): underlying virtio device driver unavailable\n",
242 snprintf(dev_name, sizeof(dev_name), "%s#%d",
243 virtio_drv_name[uc_priv->device], udev->seq);
244 str = strdup(dev_name);
248 ret = device_bind_driver(udev, virtio_drv_name[uc_priv->device],
250 if (ret == -ENOENT) {
251 debug("(%s): no driver configured\n", udev->name);
258 device_set_name_alloced(vdev);
260 INIT_LIST_HEAD(&uc_priv->vqs);
265 static int virtio_uclass_child_post_bind(struct udevice *vdev)
267 /* Acknowledge that we've seen the device */
268 virtio_add_status(vdev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
273 static int virtio_uclass_child_pre_probe(struct udevice *vdev)
275 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
278 u64 driver_features_legacy;
283 * Save the real virtio device (eg: virtio-net, virtio-blk) to
284 * the transport (parent) device's uclass priv for future use.
286 uc_priv->vdev = vdev;
289 * We always start by resetting the device, in case a previous driver
290 * messed it up. This also tests that code path a little.
292 ret = virtio_reset(vdev);
296 /* We have a driver! */
297 virtio_add_status(vdev, VIRTIO_CONFIG_S_DRIVER);
299 /* Figure out what features the device supports */
300 virtio_get_features(vdev, &device_features);
301 debug("(%s) plain device features supported %016llx\n",
302 vdev->name, device_features);
303 if (!(device_features & (1ULL << VIRTIO_F_VERSION_1)))
304 uc_priv->legacy = true;
306 /* Figure out what features the driver supports */
308 for (i = 0; i < uc_priv->feature_table_size; i++) {
309 unsigned int f = uc_priv->feature_table[i];
312 driver_features |= (1ULL << f);
315 /* Some drivers have a separate feature table for virtio v1.0 */
316 if (uc_priv->feature_table_legacy) {
317 driver_features_legacy = 0;
318 for (i = 0; i < uc_priv->feature_table_size_legacy; i++) {
319 unsigned int f = uc_priv->feature_table_legacy[i];
322 driver_features_legacy |= (1ULL << f);
325 driver_features_legacy = driver_features;
328 if (uc_priv->legacy) {
329 debug("(%s): legacy virtio device\n", vdev->name);
330 uc_priv->features = driver_features_legacy & device_features;
332 debug("(%s): v1.0 complaint virtio device\n", vdev->name);
333 uc_priv->features = driver_features & device_features;
336 /* Transport features always preserved to pass to finalize_features */
337 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
338 if ((device_features & (1ULL << i)) &&
339 (i == VIRTIO_F_VERSION_1))
340 __virtio_set_bit(vdev->parent, i);
342 debug("(%s) final negotiated features supported %016llx\n",
343 vdev->name, uc_priv->features);
344 ret = virtio_finalize_features(vdev);
351 virtio_add_status(vdev, VIRTIO_CONFIG_S_FAILED);
355 static int virtio_uclass_child_post_probe(struct udevice *vdev)
357 /* Indicates that the driver is set up and ready to drive the device */
358 virtio_add_status(vdev, VIRTIO_CONFIG_S_DRIVER_OK);
363 UCLASS_DRIVER(virtio) = {
366 .flags = DM_UC_FLAG_SEQ_ALIAS,
367 .pre_probe = virtio_uclass_pre_probe,
368 .post_probe = virtio_uclass_post_probe,
369 .child_post_bind = virtio_uclass_child_post_bind,
370 .child_pre_probe = virtio_uclass_child_pre_probe,
371 .child_post_probe = virtio_uclass_child_post_probe,
372 .per_device_auto_alloc_size = sizeof(struct virtio_dev_priv),