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.
21 #include <virtio_types.h>
25 static const char *const virtio_drv_name[VIRTIO_ID_MAX_NUM] = {
26 [VIRTIO_ID_NET] = VIRTIO_NET_DRV_NAME,
27 [VIRTIO_ID_BLOCK] = VIRTIO_BLK_DRV_NAME,
28 [VIRTIO_ID_RNG] = VIRTIO_RNG_DRV_NAME,
31 int virtio_get_config(struct udevice *vdev, unsigned int offset,
32 void *buf, unsigned int len)
34 struct dm_virtio_ops *ops;
36 ops = virtio_get_ops(vdev->parent);
38 return ops->get_config(vdev->parent, offset, buf, len);
41 int virtio_set_config(struct udevice *vdev, unsigned int offset,
42 void *buf, unsigned int len)
44 struct dm_virtio_ops *ops;
46 ops = virtio_get_ops(vdev->parent);
48 return ops->set_config(vdev->parent, offset, buf, len);
51 int virtio_generation(struct udevice *vdev, u32 *counter)
53 struct dm_virtio_ops *ops;
55 ops = virtio_get_ops(vdev->parent);
59 return ops->generation(vdev->parent, counter);
62 int virtio_get_status(struct udevice *vdev, u8 *status)
64 struct dm_virtio_ops *ops;
66 ops = virtio_get_ops(vdev->parent);
68 return ops->get_status(vdev->parent, status);
71 int virtio_set_status(struct udevice *vdev, u8 status)
73 struct dm_virtio_ops *ops;
75 ops = virtio_get_ops(vdev->parent);
77 return ops->set_status(vdev->parent, status);
80 int virtio_reset(struct udevice *vdev)
82 struct dm_virtio_ops *ops;
84 ops = virtio_get_ops(vdev->parent);
86 return ops->reset(vdev->parent);
89 int virtio_get_features(struct udevice *vdev, u64 *features)
91 struct dm_virtio_ops *ops;
93 ops = virtio_get_ops(vdev->parent);
95 return ops->get_features(vdev->parent, features);
98 int virtio_set_features(struct udevice *vdev)
100 struct dm_virtio_ops *ops;
102 ops = virtio_get_ops(vdev->parent);
104 return ops->set_features(vdev->parent);
107 int virtio_find_vqs(struct udevice *vdev, unsigned int nvqs,
108 struct virtqueue *vqs[])
110 struct dm_virtio_ops *ops;
112 ops = virtio_get_ops(vdev->parent);
114 return ops->find_vqs(vdev->parent, nvqs, vqs);
117 int virtio_del_vqs(struct udevice *vdev)
119 struct dm_virtio_ops *ops;
121 ops = virtio_get_ops(vdev->parent);
123 return ops->del_vqs(vdev->parent);
126 int virtio_notify(struct udevice *vdev, struct virtqueue *vq)
128 struct dm_virtio_ops *ops;
130 ops = virtio_get_ops(vdev->parent);
132 return ops->notify(vdev->parent, vq);
135 void virtio_add_status(struct udevice *vdev, u8 status)
139 if (!virtio_get_status(vdev, &old))
140 virtio_set_status(vdev, old | status);
143 int virtio_finalize_features(struct udevice *vdev)
145 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
149 ret = virtio_set_features(vdev);
156 virtio_add_status(vdev, VIRTIO_CONFIG_S_FEATURES_OK);
157 ret = virtio_get_status(vdev, &status);
160 if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
161 debug("(%s): device refuses features %x\n", vdev->name, status);
168 void virtio_driver_features_init(struct virtio_dev_priv *priv,
171 const u32 *feature_legacy,
172 u32 feature_legacy_size)
174 priv->feature_table = feature;
175 priv->feature_table_size = feature_size;
176 priv->feature_table_legacy = feature_legacy;
177 priv->feature_table_size_legacy = feature_legacy_size;
180 int virtio_init(void)
185 /* Enumerate all known virtio devices */
186 ret = uclass_first_device(UCLASS_VIRTIO, &bus);
191 ret = uclass_next_device(&bus);
199 static int virtio_uclass_pre_probe(struct udevice *udev)
201 struct dm_virtio_ops *ops;
203 ops = (struct dm_virtio_ops *)(udev->driver->ops);
206 * Check virtio transport driver ops here so that we don't need
207 * check these ops each time when the virtio_xxx APIs are called.
209 * Only generation op is optional. All other ops are must-have.
211 if (!ops->get_config || !ops->set_config ||
212 !ops->get_status || !ops->set_status ||
213 !ops->get_features || !ops->set_features ||
214 !ops->find_vqs || !ops->del_vqs ||
215 !ops->reset || !ops->notify)
221 static int virtio_uclass_post_probe(struct udevice *udev)
223 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
224 char dev_name[30], *str;
225 struct udevice *vdev;
228 if (uc_priv->device > VIRTIO_ID_MAX_NUM) {
229 debug("(%s): virtio device ID %d exceeds maximum num\n",
230 udev->name, uc_priv->device);
234 if (!virtio_drv_name[uc_priv->device]) {
235 debug("(%s): underlying virtio device driver unavailable\n",
240 snprintf(dev_name, sizeof(dev_name), "%s#%d",
241 virtio_drv_name[uc_priv->device], udev->seq);
242 str = strdup(dev_name);
246 ret = device_bind_driver(udev, virtio_drv_name[uc_priv->device],
248 if (ret == -ENOENT) {
249 debug("(%s): no driver configured\n", udev->name);
256 device_set_name_alloced(vdev);
258 INIT_LIST_HEAD(&uc_priv->vqs);
263 static int virtio_uclass_child_post_bind(struct udevice *vdev)
265 /* Acknowledge that we've seen the device */
266 virtio_add_status(vdev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
271 static int virtio_uclass_child_pre_probe(struct udevice *vdev)
273 struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(vdev->parent);
276 u64 driver_features_legacy;
281 * Save the real virtio device (eg: virtio-net, virtio-blk) to
282 * the transport (parent) device's uclass priv for future use.
284 uc_priv->vdev = vdev;
287 * We always start by resetting the device, in case a previous driver
288 * messed it up. This also tests that code path a little.
290 ret = virtio_reset(vdev);
294 /* We have a driver! */
295 virtio_add_status(vdev, VIRTIO_CONFIG_S_DRIVER);
297 /* Figure out what features the device supports */
298 virtio_get_features(vdev, &device_features);
299 debug("(%s) plain device features supported %016llx\n",
300 vdev->name, device_features);
301 if (!(device_features & (1ULL << VIRTIO_F_VERSION_1)))
302 uc_priv->legacy = true;
304 /* Figure out what features the driver supports */
306 for (i = 0; i < uc_priv->feature_table_size; i++) {
307 unsigned int f = uc_priv->feature_table[i];
310 driver_features |= (1ULL << f);
313 /* Some drivers have a separate feature table for virtio v1.0 */
314 if (uc_priv->feature_table_legacy) {
315 driver_features_legacy = 0;
316 for (i = 0; i < uc_priv->feature_table_size_legacy; i++) {
317 unsigned int f = uc_priv->feature_table_legacy[i];
320 driver_features_legacy |= (1ULL << f);
323 driver_features_legacy = driver_features;
326 if (uc_priv->legacy) {
327 debug("(%s): legacy virtio device\n", vdev->name);
328 uc_priv->features = driver_features_legacy & device_features;
330 debug("(%s): v1.0 complaint virtio device\n", vdev->name);
331 uc_priv->features = driver_features & device_features;
334 /* Transport features always preserved to pass to finalize_features */
335 for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
336 if ((device_features & (1ULL << i)) &&
337 (i == VIRTIO_F_VERSION_1))
338 __virtio_set_bit(vdev->parent, i);
340 debug("(%s) final negotiated features supported %016llx\n",
341 vdev->name, uc_priv->features);
342 ret = virtio_finalize_features(vdev);
349 virtio_add_status(vdev, VIRTIO_CONFIG_S_FAILED);
353 static int virtio_uclass_child_post_probe(struct udevice *vdev)
355 /* Indicates that the driver is set up and ready to drive the device */
356 virtio_add_status(vdev, VIRTIO_CONFIG_S_DRIVER_OK);
361 UCLASS_DRIVER(virtio) = {
364 .flags = DM_UC_FLAG_SEQ_ALIAS,
365 .pre_probe = virtio_uclass_pre_probe,
366 .post_probe = virtio_uclass_post_probe,
367 .child_post_bind = virtio_uclass_child_post_bind,
368 .child_pre_probe = virtio_uclass_child_pre_probe,
369 .child_post_probe = virtio_uclass_child_post_probe,
370 .per_device_auto_alloc_size = sizeof(struct virtio_dev_priv),