drivers/net/netdevsim/bus.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) 2017 Netronome Systems, Inc.
  * Copyright (C) 2019 Mellanox Technologies. All rights reserved
  */

 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>

 #include "netdevsim.h"

 static DEFINE_IDA(nsim_bus_dev_ids);
 static LIST_HEAD(nsim_bus_dev_list);
 static DEFINE_MUTEX(nsim_bus_dev_list_lock);
 static bool nsim_bus_enable;

 static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
 {
 	return container_of(dev, struct nsim_bus_dev, dev);
 }

 static ssize_t
 nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 	unsigned int num_vfs;
 	int ret;

 	ret = kstrtouint(buf, 0, &num_vfs);
 	if (ret)
 		return ret;

 	device_lock(dev);
 	ret = -ENOENT;
 	if (dev_get_drvdata(dev))
 		ret = nsim_drv_configure_vfs(nsim_bus_dev, num_vfs);
 	device_unlock(dev);

 	return ret ? ret : count;
 }

 static ssize_t
 nsim_bus_dev_numvfs_show(struct device *dev,
 			 struct device_attribute *attr, char *buf)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

 	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
 }

 static struct device_attribute nsim_bus_dev_numvfs_attr =
 	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
 	       nsim_bus_dev_numvfs_store);

 static ssize_t
 new_port_store(struct device *dev, struct device_attribute *attr,
 	       const char *buf, size_t count)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 	unsigned int port_index;
 	int ret;

 	/* Prevent to use nsim_bus_dev before initialization. */
 	if (!smp_load_acquire(&nsim_bus_dev->init))
 		return -EBUSY;
 	ret = kstrtouint(buf, 0, &port_index);
 	if (ret)
 		return ret;

 	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
 	return ret ? ret : count;
 }

 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);

 static ssize_t
 del_port_store(struct device *dev, struct device_attribute *attr,
 	       const char *buf, size_t count)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 	unsigned int port_index;
 	int ret;

 	/* Prevent to use nsim_bus_dev before initialization. */
 	if (!smp_load_acquire(&nsim_bus_dev->init))
 		return -EBUSY;
 	ret = kstrtouint(buf, 0, &port_index);
 	if (ret)
 		return ret;

 	ret = nsim_drv_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
 	return ret ? ret : count;
 }

 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);

 static struct attribute *nsim_bus_dev_attrs[] = {
 	&nsim_bus_dev_numvfs_attr.attr,
 	&nsim_bus_dev_new_port_attr.attr,
 	&nsim_bus_dev_del_port_attr.attr,
 	NULL,
 };

 static const struct attribute_group nsim_bus_dev_attr_group = {
 	.attrs = nsim_bus_dev_attrs,
 };

 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
 	&nsim_bus_dev_attr_group,
 	NULL,
 };

 static void nsim_bus_dev_release(struct device *dev)
 {
 	struct nsim_bus_dev *nsim_bus_dev;

 	nsim_bus_dev = container_of(dev, struct nsim_bus_dev, dev);
 	kfree(nsim_bus_dev);
 }

 static struct device_type nsim_bus_dev_type = {
 	.groups = nsim_bus_dev_attr_groups,
 	.release = nsim_bus_dev_release,
 };

 static struct nsim_bus_dev *
 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);

 static ssize_t
 new_device_store(const struct bus_type *bus, const char *buf, size_t count)
 {
 	unsigned int id, port_count, num_queues;
 	struct nsim_bus_dev *nsim_bus_dev;
 	int err;

 	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
 	switch (err) {
 	case 1:
 		port_count = 1;
 		fallthrough;
 	case 2:
 		num_queues = 1;
 		fallthrough;
 	case 3:
 		if (id > INT_MAX) {
 			pr_err("Value of \"id\" is too big.\n");
 			return -EINVAL;
 		}
 		break;
 	default:
 		pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint unit).\n");
 		return -EINVAL;
 	}

 	mutex_lock(&nsim_bus_dev_list_lock);
 	/* Prevent to use resource before initialization. */
 	if (!smp_load_acquire(&nsim_bus_enable)) {
 		err = -EBUSY;
 		goto err;
 	}

 	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
 	if (IS_ERR(nsim_bus_dev)) {
 		err = PTR_ERR(nsim_bus_dev);
 		goto err;
 	}

 	/* Allow using nsim_bus_dev */
 	smp_store_release(&nsim_bus_dev->init, true);

 	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
 	mutex_unlock(&nsim_bus_dev_list_lock);

 	return count;
 err:
 	mutex_unlock(&nsim_bus_dev_list_lock);
 	return err;
 }
 static BUS_ATTR_WO(new_device);

 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);

 static ssize_t
 del_device_store(const struct bus_type *bus, const char *buf, size_t count)
 {
 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
 	unsigned int id;
 	int err;

 	err = sscanf(buf, "%u", &id);
 	switch (err) {
 	case 1:
 		if (id > INT_MAX) {
 			pr_err("Value of \"id\" is too big.\n");
 			return -EINVAL;
 		}
 		break;
 	default:
 		pr_err("Format for deleting device is \"id\" (uint).\n");
 		return -EINVAL;
 	}

 	err = -ENOENT;
 	mutex_lock(&nsim_bus_dev_list_lock);
 	/* Prevent to use resource before initialization. */
 	if (!smp_load_acquire(&nsim_bus_enable)) {
 		mutex_unlock(&nsim_bus_dev_list_lock);
 		return -EBUSY;
 	}
 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
 		if (nsim_bus_dev->dev.id != id)
 			continue;
 		list_del(&nsim_bus_dev->list);
 		nsim_bus_dev_del(nsim_bus_dev);
 		err = 0;
 		break;
 	}
 	mutex_unlock(&nsim_bus_dev_list_lock);
 	return !err ? count : err;
 }
 static BUS_ATTR_WO(del_device);

 static struct attribute *nsim_bus_attrs[] = {
 	&bus_attr_new_device.attr,
 	&bus_attr_del_device.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(nsim_bus);

 static int nsim_bus_probe(struct device *dev)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

 	return nsim_drv_probe(nsim_bus_dev);
 }

 static void nsim_bus_remove(struct device *dev)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

 	nsim_drv_remove(nsim_bus_dev);
 }

 static int nsim_num_vf(struct device *dev)
 {
 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

 	return nsim_bus_dev->num_vfs;
 }

 static struct bus_type nsim_bus = {
 	.name		= DRV_NAME,
 	.dev_name	= DRV_NAME,
 	.bus_groups	= nsim_bus_groups,
 	.probe		= nsim_bus_probe,
 	.remove		= nsim_bus_remove,
 	.num_vf		= nsim_num_vf,
 };

 #define NSIM_BUS_DEV_MAX_VFS 4

 static struct nsim_bus_dev *
 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
 {
 	struct nsim_bus_dev *nsim_bus_dev;
 	int err;

 	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
 	if (!nsim_bus_dev)
 		return ERR_PTR(-ENOMEM);

 	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
 	if (err < 0)
 		goto err_nsim_bus_dev_free;
 	nsim_bus_dev->dev.id = err;
 	nsim_bus_dev->dev.bus = &nsim_bus;
 	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
 	nsim_bus_dev->port_count = port_count;
 	nsim_bus_dev->num_queues = num_queues;
 	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
 	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
 	/* Disallow using nsim_bus_dev */
 	smp_store_release(&nsim_bus_dev->init, false);

 	err = device_register(&nsim_bus_dev->dev);
 	if (err)
 		goto err_nsim_bus_dev_id_free;

 	return nsim_bus_dev;

 err_nsim_bus_dev_id_free:
 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
 	put_device(&nsim_bus_dev->dev);
 	nsim_bus_dev = NULL;
 err_nsim_bus_dev_free:
 	kfree(nsim_bus_dev);
 	return ERR_PTR(err);
 }

 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
 {
 	/* Disallow using nsim_bus_dev */
 	smp_store_release(&nsim_bus_dev->init, false);
 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
 	device_unregister(&nsim_bus_dev->dev);
 }

 static struct device_driver nsim_driver = {
 	.name		= DRV_NAME,
 	.bus		= &nsim_bus,
 	.owner		= THIS_MODULE,
 };

 int nsim_bus_init(void)
 {
 	int err;

 	err = bus_register(&nsim_bus);
 	if (err)
 		return err;
 	err = driver_register(&nsim_driver);
 	if (err)
 		goto err_bus_unregister;
 	/* Allow using resources */
 	smp_store_release(&nsim_bus_enable, true);
 	return 0;

 err_bus_unregister:
 	bus_unregister(&nsim_bus);
 	return err;
 }

 void nsim_bus_exit(void)
 {
 	struct nsim_bus_dev *nsim_bus_dev, *tmp;

 	/* Disallow using resources */
 	smp_store_release(&nsim_bus_enable, false);

 	mutex_lock(&nsim_bus_dev_list_lock);
 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
 		list_del(&nsim_bus_dev->list);
 		nsim_bus_dev_del(nsim_bus_dev);
 	}
 	mutex_unlock(&nsim_bus_dev_list_lock);

 	driver_unregister(&nsim_driver);
 	bus_unregister(&nsim_bus);
 }
	// SPDX-License-Identifier: GPL-2.0
	/* Copyright (C) 2017 Netronome Systems, Inc.
	* Copyright (C) 2019 Mellanox Technologies. All rights reserved
	*/

	#include <linux/device.h>
	#include <linux/idr.h>
	#include <linux/kernel.h>
	#include <linux/list.h>
	#include <linux/mutex.h>
	#include <linux/slab.h>
	#include <linux/sysfs.h>

	#include "netdevsim.h"

	static DEFINE_IDA(nsim_bus_dev_ids);
	static LIST_HEAD(nsim_bus_dev_list);
	static DEFINE_MUTEX(nsim_bus_dev_list_lock);
	static bool nsim_bus_enable;

	static struct nsim_bus_dev to_nsim_bus_dev(struct device dev)
	{
	return container_of(dev, struct nsim_bus_dev, dev);
	}

	static ssize_t
	nsim_bus_dev_numvfs_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
	unsigned int num_vfs;
	int ret;

	ret = kstrtouint(buf, 0, &num_vfs);
	if (ret)
	return ret;

	device_lock(dev);
	ret = -ENOENT;
	if (dev_get_drvdata(dev))
	ret = nsim_drv_configure_vfs(nsim_bus_dev, num_vfs);
	device_unlock(dev);

	return ret ? ret : count;
	}

	static ssize_t
	nsim_bus_dev_numvfs_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
	}

	static struct device_attribute nsim_bus_dev_numvfs_attr =
	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
	nsim_bus_dev_numvfs_store);

	static ssize_t
	new_port_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
	unsigned int port_index;
	int ret;

	/* Prevent to use nsim_bus_dev before initialization. */
	if (!smp_load_acquire(&nsim_bus_dev->init))
	return -EBUSY;
	ret = kstrtouint(buf, 0, &port_index);
	if (ret)
	return ret;

	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
	return ret ? ret : count;
	}

	static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);

	static ssize_t
	del_port_store(struct device dev, struct device_attribute attr,
	const char *buf, size_t count)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
	unsigned int port_index;
	int ret;

	/* Prevent to use nsim_bus_dev before initialization. */
	if (!smp_load_acquire(&nsim_bus_dev->init))
	return -EBUSY;
	ret = kstrtouint(buf, 0, &port_index);
	if (ret)
	return ret;

	ret = nsim_drv_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
	return ret ? ret : count;
	}

	static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);

	static struct attribute *nsim_bus_dev_attrs[] = {
	&nsim_bus_dev_numvfs_attr.attr,
	&nsim_bus_dev_new_port_attr.attr,
	&nsim_bus_dev_del_port_attr.attr,
	NULL,
	};

	static const struct attribute_group nsim_bus_dev_attr_group = {
	.attrs = nsim_bus_dev_attrs,
	};

	static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
	&nsim_bus_dev_attr_group,
	NULL,
	};

	static void nsim_bus_dev_release(struct device *dev)
	{
	struct nsim_bus_dev *nsim_bus_dev;

	nsim_bus_dev = container_of(dev, struct nsim_bus_dev, dev);
	kfree(nsim_bus_dev);
	}

	static struct device_type nsim_bus_dev_type = {
	.groups = nsim_bus_dev_attr_groups,
	.release = nsim_bus_dev_release,
	};

	static struct nsim_bus_dev *
	nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);

	static ssize_t
	new_device_store(const struct bus_type bus, const char buf, size_t count)
	{
	unsigned int id, port_count, num_queues;
	struct nsim_bus_dev *nsim_bus_dev;
	int err;

	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
	switch (err) {
	case 1:
	port_count = 1;
	fallthrough;
	case 2:
	num_queues = 1;
	fallthrough;
	case 3:
	if (id > INT_MAX) {
	pr_err("Value of \"id\" is too big.\n");
	return -EINVAL;
	}
	break;
	default:
	pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint unit).\n");
	return -EINVAL;
	}

	mutex_lock(&nsim_bus_dev_list_lock);
	/* Prevent to use resource before initialization. */
	if (!smp_load_acquire(&nsim_bus_enable)) {
	err = -EBUSY;
	goto err;
	}

	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
	if (IS_ERR(nsim_bus_dev)) {
	err = PTR_ERR(nsim_bus_dev);
	goto err;
	}

	/* Allow using nsim_bus_dev */
	smp_store_release(&nsim_bus_dev->init, true);

	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
	mutex_unlock(&nsim_bus_dev_list_lock);

	return count;
	err:
	mutex_unlock(&nsim_bus_dev_list_lock);
	return err;
	}
	static BUS_ATTR_WO(new_device);

	static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);

	static ssize_t
	del_device_store(const struct bus_type bus, const char buf, size_t count)
	{
	struct nsim_bus_dev nsim_bus_dev, tmp;
	unsigned int id;
	int err;

	err = sscanf(buf, "%u", &id);
	switch (err) {
	case 1:
	if (id > INT_MAX) {
	pr_err("Value of \"id\" is too big.\n");
	return -EINVAL;
	}
	break;
	default:
	pr_err("Format for deleting device is \"id\" (uint).\n");
	return -EINVAL;
	}

	err = -ENOENT;
	mutex_lock(&nsim_bus_dev_list_lock);
	/* Prevent to use resource before initialization. */
	if (!smp_load_acquire(&nsim_bus_enable)) {
	mutex_unlock(&nsim_bus_dev_list_lock);
	return -EBUSY;
	}
	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
	if (nsim_bus_dev->dev.id != id)
	continue;
	list_del(&nsim_bus_dev->list);
	nsim_bus_dev_del(nsim_bus_dev);
	err = 0;
	break;
	}
	mutex_unlock(&nsim_bus_dev_list_lock);
	return !err ? count : err;
	}
	static BUS_ATTR_WO(del_device);

	static struct attribute *nsim_bus_attrs[] = {
	&bus_attr_new_device.attr,
	&bus_attr_del_device.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(nsim_bus);

	static int nsim_bus_probe(struct device *dev)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

	return nsim_drv_probe(nsim_bus_dev);
	}

	static void nsim_bus_remove(struct device *dev)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

	nsim_drv_remove(nsim_bus_dev);
	}

	static int nsim_num_vf(struct device *dev)
	{
	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);

	return nsim_bus_dev->num_vfs;
	}

	static struct bus_type nsim_bus = {
	.name = DRV_NAME,
	.dev_name = DRV_NAME,
	.bus_groups = nsim_bus_groups,
	.probe = nsim_bus_probe,
	.remove = nsim_bus_remove,
	.num_vf = nsim_num_vf,
	};

	#define NSIM_BUS_DEV_MAX_VFS 4

	static struct nsim_bus_dev *
	nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
	{
	struct nsim_bus_dev *nsim_bus_dev;
	int err;

	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
	if (!nsim_bus_dev)
	return ERR_PTR(-ENOMEM);

	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
	if (err < 0)
	goto err_nsim_bus_dev_free;
	nsim_bus_dev->dev.id = err;
	nsim_bus_dev->dev.bus = &nsim_bus;
	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
	nsim_bus_dev->port_count = port_count;
	nsim_bus_dev->num_queues = num_queues;
	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
	/* Disallow using nsim_bus_dev */
	smp_store_release(&nsim_bus_dev->init, false);

	err = device_register(&nsim_bus_dev->dev);
	if (err)
	goto err_nsim_bus_dev_id_free;

	return nsim_bus_dev;

	err_nsim_bus_dev_id_free:
	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
	put_device(&nsim_bus_dev->dev);
	nsim_bus_dev = NULL;
	err_nsim_bus_dev_free:
	kfree(nsim_bus_dev);
	return ERR_PTR(err);
	}

	static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
	{
	/* Disallow using nsim_bus_dev */
	smp_store_release(&nsim_bus_dev->init, false);
	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
	device_unregister(&nsim_bus_dev->dev);
	}

	static struct device_driver nsim_driver = {
	.name = DRV_NAME,
	.bus = &nsim_bus,
	.owner = THIS_MODULE,
	};

	int nsim_bus_init(void)
	{
	int err;

	err = bus_register(&nsim_bus);
	if (err)
	return err;
	err = driver_register(&nsim_driver);
	if (err)
	goto err_bus_unregister;
	/* Allow using resources */
	smp_store_release(&nsim_bus_enable, true);
	return 0;

	err_bus_unregister:
	bus_unregister(&nsim_bus);
	return err;
	}

	void nsim_bus_exit(void)
	{
	struct nsim_bus_dev nsim_bus_dev, tmp;

	/* Disallow using resources */
	smp_store_release(&nsim_bus_enable, false);

	mutex_lock(&nsim_bus_dev_list_lock);
	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
	list_del(&nsim_bus_dev->list);
	nsim_bus_dev_del(nsim_bus_dev);
	}
	mutex_unlock(&nsim_bus_dev_list_lock);

	driver_unregister(&nsim_driver);
	bus_unregister(&nsim_bus);
	}