131 lines
2.9 KiB
C
131 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* IOMMU sysfs class support
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*
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* Copyright (C) 2014 Red Hat, Inc. All rights reserved.
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* Author: Alex Williamson <alex.williamson@redhat.com>
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*/
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#include <linux/device.h>
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#include <linux/iommu.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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/*
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* We provide a common class "devices" group which initially has no attributes.
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* As devices are added to the IOMMU, we'll add links to the group.
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*/
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static struct attribute *devices_attr[] = {
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NULL,
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};
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static const struct attribute_group devices_attr_group = {
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.name = "devices",
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.attrs = devices_attr,
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};
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static const struct attribute_group *dev_groups[] = {
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&devices_attr_group,
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NULL,
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};
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static void release_device(struct device *dev)
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{
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kfree(dev);
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}
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static struct class iommu_class = {
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.name = "iommu",
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.dev_release = release_device,
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.dev_groups = dev_groups,
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};
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static int __init iommu_dev_init(void)
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{
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return class_register(&iommu_class);
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}
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postcore_initcall(iommu_dev_init);
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/*
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* Init the struct device for the IOMMU. IOMMU specific attributes can
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* be provided as an attribute group, allowing a unique namespace per
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* IOMMU type.
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*/
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int iommu_device_sysfs_add(struct iommu_device *iommu,
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struct device *parent,
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const struct attribute_group **groups,
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const char *fmt, ...)
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{
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va_list vargs;
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int ret;
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iommu->dev = kzalloc(sizeof(*iommu->dev), GFP_KERNEL);
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if (!iommu->dev)
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return -ENOMEM;
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device_initialize(iommu->dev);
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iommu->dev->class = &iommu_class;
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iommu->dev->parent = parent;
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iommu->dev->groups = groups;
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va_start(vargs, fmt);
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ret = kobject_set_name_vargs(&iommu->dev->kobj, fmt, vargs);
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va_end(vargs);
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if (ret)
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goto error;
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ret = device_add(iommu->dev);
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if (ret)
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goto error;
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dev_set_drvdata(iommu->dev, iommu);
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return 0;
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error:
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put_device(iommu->dev);
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return ret;
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}
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void iommu_device_sysfs_remove(struct iommu_device *iommu)
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{
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dev_set_drvdata(iommu->dev, NULL);
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device_unregister(iommu->dev);
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iommu->dev = NULL;
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}
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/*
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* IOMMU drivers can indicate a device is managed by a given IOMMU using
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* this interface. A link to the device will be created in the "devices"
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* directory of the IOMMU device in sysfs and an "iommu" link will be
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* created under the linked device, pointing back at the IOMMU device.
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*/
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int iommu_device_link(struct iommu_device *iommu, struct device *link)
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{
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int ret;
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if (!iommu || IS_ERR(iommu))
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return -ENODEV;
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ret = sysfs_add_link_to_group(&iommu->dev->kobj, "devices",
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&link->kobj, dev_name(link));
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if (ret)
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return ret;
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ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev->kobj, "iommu");
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if (ret)
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sysfs_remove_link_from_group(&iommu->dev->kobj, "devices",
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dev_name(link));
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return ret;
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}
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void iommu_device_unlink(struct iommu_device *iommu, struct device *link)
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{
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if (!iommu || IS_ERR(iommu))
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return;
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sysfs_remove_link(&link->kobj, "iommu");
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sysfs_remove_link_from_group(&iommu->dev->kobj, "devices", dev_name(link));
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}
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