Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / iommu / iommu-sysfs.c

diff --git a/kernel/drivers/iommu/iommu-sysfs.c b/kernel/drivers/iommu/iommu-sysfs.c
new file mode 100644 (file)
index 0000000..39b2d91
--- /dev/null
+++ b/kernel/drivers/iommu/iommu-sysfs.c
@@ -0,0 +1,134 @@
+/*
+ * 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>
+#include <linux/slab.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));
+}