diff options
Diffstat (limited to 'drivers/vdpa/vdpa.c')
| -rw-r--r-- | drivers/vdpa/vdpa.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c new file mode 100644 index 000000000000..e9ed6a2b635b --- /dev/null +++ b/drivers/vdpa/vdpa.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vDPA bus. + * + * Copyright (c) 2020, Red Hat. All rights reserved. + * Author: Jason Wang <jasowang@redhat.com> + * + */ + +#include <linux/module.h> +#include <linux/idr.h> +#include <linux/slab.h> +#include <linux/vdpa.h> + +static DEFINE_IDA(vdpa_index_ida); + +static int vdpa_dev_probe(struct device *d) +{ + struct vdpa_device *vdev = dev_to_vdpa(d); + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); + int ret = 0; + + if (drv && drv->probe) + ret = drv->probe(vdev); + + return ret; +} + +static int vdpa_dev_remove(struct device *d) +{ + struct vdpa_device *vdev = dev_to_vdpa(d); + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); + + if (drv && drv->remove) + drv->remove(vdev); + + return 0; +} + +static struct bus_type vdpa_bus = { + .name = "vdpa", + .probe = vdpa_dev_probe, + .remove = vdpa_dev_remove, +}; + +static void vdpa_release_dev(struct device *d) +{ + struct vdpa_device *vdev = dev_to_vdpa(d); + const struct vdpa_config_ops *ops = vdev->config; + + if (ops->free) + ops->free(vdev); + + ida_simple_remove(&vdpa_index_ida, vdev->index); + kfree(vdev); +} + +/** + * __vdpa_alloc_device - allocate and initilaize a vDPA device + * This allows driver to some prepartion after device is + * initialized but before registered. + * @parent: the parent device + * @config: the bus operations that is supported by this device + * @size: size of the parent structure that contains private data + * + * Drvier should use vdap_alloc_device() wrapper macro instead of + * using this directly. + * + * Returns an error when parent/config/dma_dev is not set or fail to get + * ida. + */ +struct vdpa_device *__vdpa_alloc_device(struct device *parent, + const struct vdpa_config_ops *config, + size_t size) +{ + struct vdpa_device *vdev; + int err = -EINVAL; + + if (!config) + goto err; + + if (!!config->dma_map != !!config->dma_unmap) + goto err; + + err = -ENOMEM; + vdev = kzalloc(size, GFP_KERNEL); + if (!vdev) + goto err; + + err = ida_simple_get(&vdpa_index_ida, 0, 0, GFP_KERNEL); + if (err < 0) + goto err_ida; + + vdev->dev.bus = &vdpa_bus; + vdev->dev.parent = parent; + vdev->dev.release = vdpa_release_dev; + vdev->index = err; + vdev->config = config; + + err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index); + if (err) + goto err_name; + + device_initialize(&vdev->dev); + + return vdev; + +err_name: + ida_simple_remove(&vdpa_index_ida, vdev->index); +err_ida: + kfree(vdev); +err: + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(__vdpa_alloc_device); + +/** + * vdpa_register_device - register a vDPA device + * Callers must have a succeed call of vdpa_init_device() before. + * @vdev: the vdpa device to be registered to vDPA bus + * + * Returns an error when fail to add to vDPA bus + */ +int vdpa_register_device(struct vdpa_device *vdev) +{ + return device_add(&vdev->dev); +} +EXPORT_SYMBOL_GPL(vdpa_register_device); + +/** + * vdpa_unregister_device - unregister a vDPA device + * @vdev: the vdpa device to be unregisted from vDPA bus + */ +void vdpa_unregister_device(struct vdpa_device *vdev) +{ + device_unregister(&vdev->dev); +} +EXPORT_SYMBOL_GPL(vdpa_unregister_device); + +/** + * __vdpa_register_driver - register a vDPA device driver + * @drv: the vdpa device driver to be registered + * @owner: module owner of the driver + * + * Returns an err when fail to do the registration + */ +int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner) +{ + drv->driver.bus = &vdpa_bus; + drv->driver.owner = owner; + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(__vdpa_register_driver); + +/** + * vdpa_unregister_driver - unregister a vDPA device driver + * @drv: the vdpa device driver to be unregistered + */ +void vdpa_unregister_driver(struct vdpa_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(vdpa_unregister_driver); + +static int vdpa_init(void) +{ + return bus_register(&vdpa_bus); +} + +static void __exit vdpa_exit(void) +{ + bus_unregister(&vdpa_bus); + ida_destroy(&vdpa_index_ida); +} +core_initcall(vdpa_init); +module_exit(vdpa_exit); + +MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>"); +MODULE_LICENSE("GPL v2"); |