diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/iommu/Makefile | 1 | ||||
-rw-r--r-- | drivers/iommu/iommu-sysfs.c | 133 |
2 files changed, 134 insertions, 0 deletions
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 8893bad048e0..7788ebd1f6e2 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -1,5 +1,6 @@ obj-$(CONFIG_IOMMU_API) += iommu.o obj-$(CONFIG_IOMMU_API) += iommu-traces.o +obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o obj-$(CONFIG_OF_IOMMU) += of_iommu.o obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o diff --git a/drivers/iommu/iommu-sysfs.c b/drivers/iommu/iommu-sysfs.c new file mode 100644 index 000000000000..d6939234a009 --- /dev/null +++ b/drivers/iommu/iommu-sysfs.c @@ -0,0 +1,133 @@ +/* + * IOMMU sysfs class support + * + * Copyright (C) 2014 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson <alex.williamson@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/device.h> +#include <linux/iommu.h> +#include <linux/module.h> + +/* + * We provide a common class "devices" group which initially has no attributes. + * As devices are added to the IOMMU, we'll add links to the group. + */ +static struct attribute *devices_attr[] = { + NULL, +}; + +static const struct attribute_group iommu_devices_attr_group = { + .name = "devices", + .attrs = devices_attr, +}; + +static const struct attribute_group *iommu_dev_groups[] = { + &iommu_devices_attr_group, + NULL, +}; + +static void iommu_release_device(struct device *dev) +{ + kfree(dev); +} + +static struct class iommu_class = { + .name = "iommu", + .dev_release = iommu_release_device, + .dev_groups = iommu_dev_groups, +}; + +static int __init iommu_dev_init(void) +{ + return class_register(&iommu_class); +} +postcore_initcall(iommu_dev_init); + +/* + * Create an IOMMU device and return a pointer to it. IOMMU specific + * attributes can be provided as an attribute group, allowing a unique + * namespace per IOMMU type. + */ +struct device *iommu_device_create(struct device *parent, void *drvdata, + const struct attribute_group **groups, + const char *fmt, ...) +{ + struct device *dev; + va_list vargs; + int ret; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + device_initialize(dev); + + dev->class = &iommu_class; + dev->parent = parent; + dev->groups = groups; + dev_set_drvdata(dev, drvdata); + + va_start(vargs, fmt); + ret = kobject_set_name_vargs(&dev->kobj, fmt, vargs); + va_end(vargs); + if (ret) + goto error; + + ret = device_add(dev); + if (ret) + goto error; + + return dev; + +error: + put_device(dev); + return ERR_PTR(ret); +} + +void iommu_device_destroy(struct device *dev) +{ + if (!dev || IS_ERR(dev)) + return; + + device_unregister(dev); +} + +/* + * IOMMU drivers can indicate a device is managed by a given IOMMU using + * this interface. A link to the device will be created in the "devices" + * directory of the IOMMU device in sysfs and an "iommu" link will be + * created under the linked device, pointing back at the IOMMU device. + */ +int iommu_device_link(struct device *dev, struct device *link) +{ + int ret; + + if (!dev || IS_ERR(dev)) + return -ENODEV; + + ret = sysfs_add_link_to_group(&dev->kobj, "devices", + &link->kobj, dev_name(link)); + if (ret) + return ret; + + ret = sysfs_create_link_nowarn(&link->kobj, &dev->kobj, "iommu"); + if (ret) + sysfs_remove_link_from_group(&dev->kobj, "devices", + dev_name(link)); + + return ret; +} + +void iommu_device_unlink(struct device *dev, struct device *link) +{ + if (!dev || IS_ERR(dev)) + return; + + sysfs_remove_link(&link->kobj, "iommu"); + sysfs_remove_link_from_group(&dev->kobj, "devices", dev_name(link)); +} |