diff options
Diffstat (limited to 'drivers/virtio/virtio_vdpa.c')
| -rw-r--r-- | drivers/virtio/virtio_vdpa.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c new file mode 100644 index 000000000000..c30eb55030be --- /dev/null +++ b/drivers/virtio/virtio_vdpa.c @@ -0,0 +1,396 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VIRTIO based driver for vDPA device + * + * Copyright (c) 2020, Red Hat. All rights reserved. + * Author: Jason Wang <jasowang@redhat.com> + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/uuid.h> +#include <linux/virtio.h> +#include <linux/vdpa.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ring.h> + +#define MOD_VERSION "0.1" +#define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>" +#define MOD_DESC "vDPA bus driver for virtio devices" +#define MOD_LICENSE "GPL v2" + +struct virtio_vdpa_device { + struct virtio_device vdev; + struct vdpa_device *vdpa; + u64 features; + + /* The lock to protect virtqueue list */ + spinlock_t lock; + /* List of virtio_vdpa_vq_info */ + struct list_head virtqueues; +}; + +struct virtio_vdpa_vq_info { + /* the actual virtqueue */ + struct virtqueue *vq; + + /* the list node for the virtqueues list */ + struct list_head node; +}; + +static inline struct virtio_vdpa_device * +to_virtio_vdpa_device(struct virtio_device *dev) +{ + return container_of(dev, struct virtio_vdpa_device, vdev); +} + +static struct vdpa_device *vd_get_vdpa(struct virtio_device *vdev) +{ + return to_virtio_vdpa_device(vdev)->vdpa; +} + +static void virtio_vdpa_get(struct virtio_device *vdev, unsigned offset, + void *buf, unsigned len) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + ops->get_config(vdpa, offset, buf, len); +} + +static void virtio_vdpa_set(struct virtio_device *vdev, unsigned offset, + const void *buf, unsigned len) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + ops->set_config(vdpa, offset, buf, len); +} + +static u32 virtio_vdpa_generation(struct virtio_device *vdev) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + if (ops->get_generation) + return ops->get_generation(vdpa); + + return 0; +} + +static u8 virtio_vdpa_get_status(struct virtio_device *vdev) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->get_status(vdpa); +} + +static void virtio_vdpa_set_status(struct virtio_device *vdev, u8 status) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->set_status(vdpa, status); +} + +static void virtio_vdpa_reset(struct virtio_device *vdev) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->set_status(vdpa, 0); +} + +static bool virtio_vdpa_notify(struct virtqueue *vq) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vq->vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + ops->kick_vq(vdpa, vq->index); + + return true; +} + +static irqreturn_t virtio_vdpa_config_cb(void *private) +{ + struct virtio_vdpa_device *vd_dev = private; + + virtio_config_changed(&vd_dev->vdev); + + return IRQ_HANDLED; +} + +static irqreturn_t virtio_vdpa_virtqueue_cb(void *private) +{ + struct virtio_vdpa_vq_info *info = private; + + return vring_interrupt(0, info->vq); +} + +static struct virtqueue * +virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, + void (*callback)(struct virtqueue *vq), + const char *name, bool ctx) +{ + struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + struct virtio_vdpa_vq_info *info; + struct vdpa_callback cb; + struct virtqueue *vq; + u64 desc_addr, driver_addr, device_addr; + unsigned long flags; + u32 align, num; + int err; + + if (!name) + return NULL; + + /* Queue shouldn't already be set up. */ + if (ops->get_vq_ready(vdpa, index)) + return ERR_PTR(-ENOENT); + + /* Allocate and fill out our active queue description */ + info = kmalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return ERR_PTR(-ENOMEM); + + num = ops->get_vq_num_max(vdpa); + if (num == 0) { + err = -ENOENT; + goto error_new_virtqueue; + } + + /* Create the vring */ + align = ops->get_vq_align(vdpa); + vq = vring_create_virtqueue(index, num, align, vdev, + true, true, ctx, + virtio_vdpa_notify, callback, name); + if (!vq) { + err = -ENOMEM; + goto error_new_virtqueue; + } + + /* Setup virtqueue callback */ + cb.callback = virtio_vdpa_virtqueue_cb; + cb.private = info; + ops->set_vq_cb(vdpa, index, &cb); + ops->set_vq_num(vdpa, index, virtqueue_get_vring_size(vq)); + + desc_addr = virtqueue_get_desc_addr(vq); + driver_addr = virtqueue_get_avail_addr(vq); + device_addr = virtqueue_get_used_addr(vq); + + if (ops->set_vq_address(vdpa, index, + desc_addr, driver_addr, + device_addr)) { + err = -EINVAL; + goto err_vq; + } + + ops->set_vq_ready(vdpa, index, 1); + + vq->priv = info; + info->vq = vq; + + spin_lock_irqsave(&vd_dev->lock, flags); + list_add(&info->node, &vd_dev->virtqueues); + spin_unlock_irqrestore(&vd_dev->lock, flags); + + return vq; + +err_vq: + vring_del_virtqueue(vq); +error_new_virtqueue: + ops->set_vq_ready(vdpa, index, 0); + /* VDPA driver should make sure vq is stopeed here */ + WARN_ON(ops->get_vq_ready(vdpa, index)); + kfree(info); + return ERR_PTR(err); +} + +static void virtio_vdpa_del_vq(struct virtqueue *vq) +{ + struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vq->vdev); + struct vdpa_device *vdpa = vd_dev->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + struct virtio_vdpa_vq_info *info = vq->priv; + unsigned int index = vq->index; + unsigned long flags; + + spin_lock_irqsave(&vd_dev->lock, flags); + list_del(&info->node); + spin_unlock_irqrestore(&vd_dev->lock, flags); + + /* Select and deactivate the queue */ + ops->set_vq_ready(vdpa, index, 0); + WARN_ON(ops->get_vq_ready(vdpa, index)); + + vring_del_virtqueue(vq); + + kfree(info); +} + +static void virtio_vdpa_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) + virtio_vdpa_del_vq(vq); +} + +static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char * const names[], + const bool *ctx, + struct irq_affinity *desc) +{ + struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + struct vdpa_callback cb; + int i, err, queue_idx = 0; + + for (i = 0; i < nvqs; ++i) { + if (!names[i]) { + vqs[i] = NULL; + continue; + } + + vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++, + callbacks[i], names[i], ctx ? + ctx[i] : false); + if (IS_ERR(vqs[i])) { + err = PTR_ERR(vqs[i]); + goto err_setup_vq; + } + } + + cb.callback = virtio_vdpa_config_cb; + cb.private = vd_dev; + ops->set_config_cb(vdpa, &cb); + + return 0; + +err_setup_vq: + virtio_vdpa_del_vqs(vdev); + return err; +} + +static u64 virtio_vdpa_get_features(struct virtio_device *vdev) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->get_features(vdpa); +} + +static int virtio_vdpa_finalize_features(struct virtio_device *vdev) +{ + struct vdpa_device *vdpa = vd_get_vdpa(vdev); + const struct vdpa_config_ops *ops = vdpa->config; + + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + return ops->set_features(vdpa, vdev->features); +} + +static const char *virtio_vdpa_bus_name(struct virtio_device *vdev) +{ + struct virtio_vdpa_device *vd_dev = to_virtio_vdpa_device(vdev); + struct vdpa_device *vdpa = vd_dev->vdpa; + + return dev_name(&vdpa->dev); +} + +static const struct virtio_config_ops virtio_vdpa_config_ops = { + .get = virtio_vdpa_get, + .set = virtio_vdpa_set, + .generation = virtio_vdpa_generation, + .get_status = virtio_vdpa_get_status, + .set_status = virtio_vdpa_set_status, + .reset = virtio_vdpa_reset, + .find_vqs = virtio_vdpa_find_vqs, + .del_vqs = virtio_vdpa_del_vqs, + .get_features = virtio_vdpa_get_features, + .finalize_features = virtio_vdpa_finalize_features, + .bus_name = virtio_vdpa_bus_name, +}; + +static void virtio_vdpa_release_dev(struct device *_d) +{ + struct virtio_device *vdev = + container_of(_d, struct virtio_device, dev); + struct virtio_vdpa_device *vd_dev = + container_of(vdev, struct virtio_vdpa_device, vdev); + + kfree(vd_dev); +} + +static int virtio_vdpa_probe(struct vdpa_device *vdpa) +{ + const struct vdpa_config_ops *ops = vdpa->config; + struct virtio_vdpa_device *vd_dev, *reg_dev = NULL; + int ret = -EINVAL; + + vd_dev = kzalloc(sizeof(*vd_dev), GFP_KERNEL); + if (!vd_dev) + return -ENOMEM; + + vd_dev->vdev.dev.parent = vdpa_get_dma_dev(vdpa); + vd_dev->vdev.dev.release = virtio_vdpa_release_dev; + vd_dev->vdev.config = &virtio_vdpa_config_ops; + vd_dev->vdpa = vdpa; + INIT_LIST_HEAD(&vd_dev->virtqueues); + spin_lock_init(&vd_dev->lock); + + vd_dev->vdev.id.device = ops->get_device_id(vdpa); + if (vd_dev->vdev.id.device == 0) + goto err; + + vd_dev->vdev.id.vendor = ops->get_vendor_id(vdpa); + ret = register_virtio_device(&vd_dev->vdev); + reg_dev = vd_dev; + if (ret) + goto err; + + vdpa_set_drvdata(vdpa, vd_dev); + + return 0; + +err: + if (reg_dev) + put_device(&vd_dev->vdev.dev); + else + kfree(vd_dev); + return ret; +} + +static void virtio_vdpa_remove(struct vdpa_device *vdpa) +{ + struct virtio_vdpa_device *vd_dev = vdpa_get_drvdata(vdpa); + + unregister_virtio_device(&vd_dev->vdev); +} + +static struct vdpa_driver virtio_vdpa_driver = { + .driver = { + .name = "virtio_vdpa", + }, + .probe = virtio_vdpa_probe, + .remove = virtio_vdpa_remove, +}; + +module_vdpa_driver(virtio_vdpa_driver); + +MODULE_VERSION(MOD_VERSION); +MODULE_LICENSE(MOD_LICENSE); +MODULE_AUTHOR(MOD_AUTHOR); +MODULE_DESCRIPTION(MOD_DESC); |