linux/drivers/vdpa/vdpa.c
Parav Pandit 418eddef05 vdpa: Use simpler version of ida allocation
vdpa doesn't have any specific need to define start and end range of the
device index.
Hence use the simper version of the ida allocator.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20201112064005.349268-3-parav@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-12-18 16:14:31 -05:00

185 lines
4.1 KiB
C

// 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
* @nvqs: number of virtqueues supported by this device
* @size: size of the parent structure that contains private data
*
* Driver should use vdpa_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,
int nvqs,
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_alloc(&vdpa_index_ida, 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;
vdev->features_valid = false;
vdev->nvqs = nvqs;
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_alloc_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");