Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 767 insertions, 0 deletions

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
new file mode 100644
index 000000000..0ea64e24e
--- /dev/null
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -0,0 +1,767 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * configfs to configure the PCI endpoint
+ *
+ * Copyright (C) 2017 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/module.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+#include <linux/pci-ep-cfs.h>
+
+static DEFINE_IDR(functions_idr);
+static DEFINE_MUTEX(functions_mutex);
+static struct config_group *functions_group;
+static struct config_group *controllers_group;
+
+struct pci_epf_group {
+	struct config_group group;
+	struct config_group primary_epc_group;
+	struct config_group secondary_epc_group;
+	struct config_group *type_group;
+	struct delayed_work cfs_work;
+	struct pci_epf *epf;
+	int index;
+};
+
+struct pci_epc_group {
+	struct config_group group;
+	struct pci_epc *epc;
+	bool start;
+};
+
+static inline struct pci_epf_group *to_pci_epf_group(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct pci_epf_group, group);
+}
+
+static inline struct pci_epc_group *to_pci_epc_group(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct pci_epc_group, group);
+}
+
+static int pci_secondary_epc_epf_link(struct config_item *epf_item,
+				      struct config_item *epc_item)
+{
+	int ret;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
+
+	ret = pci_epc_add_epf(epc, epf, SECONDARY_INTERFACE);
+	if (ret)
+		return ret;
+
+	ret = pci_epf_bind(epf);
+	if (ret) {
+		pci_epc_remove_epf(epc, epf, SECONDARY_INTERFACE);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void pci_secondary_epc_epf_unlink(struct config_item *epc_item,
+					 struct config_item *epf_item)
+{
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+
+	WARN_ON_ONCE(epc_group->start);
+
+	epc = epc_group->epc;
+	epf = epf_group->epf;
+	pci_epf_unbind(epf);
+	pci_epc_remove_epf(epc, epf, SECONDARY_INTERFACE);
+}
+
+static struct configfs_item_operations pci_secondary_epc_item_ops = {
+	.allow_link	= pci_secondary_epc_epf_link,
+	.drop_link	= pci_secondary_epc_epf_unlink,
+};
+
+static const struct config_item_type pci_secondary_epc_type = {
+	.ct_item_ops	= &pci_secondary_epc_item_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct config_group
+*pci_ep_cfs_add_secondary_group(struct pci_epf_group *epf_group)
+{
+	struct config_group *secondary_epc_group;
+
+	secondary_epc_group = &epf_group->secondary_epc_group;
+	config_group_init_type_name(secondary_epc_group, "secondary",
+				    &pci_secondary_epc_type);
+	configfs_register_group(&epf_group->group, secondary_epc_group);
+
+	return secondary_epc_group;
+}
+
+static int pci_primary_epc_epf_link(struct config_item *epf_item,
+				    struct config_item *epc_item)
+{
+	int ret;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
+
+	ret = pci_epc_add_epf(epc, epf, PRIMARY_INTERFACE);
+	if (ret)
+		return ret;
+
+	ret = pci_epf_bind(epf);
+	if (ret) {
+		pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void pci_primary_epc_epf_unlink(struct config_item *epc_item,
+				       struct config_item *epf_item)
+{
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item->ci_parent);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+
+	WARN_ON_ONCE(epc_group->start);
+
+	epc = epc_group->epc;
+	epf = epf_group->epf;
+	pci_epf_unbind(epf);
+	pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+}
+
+static struct configfs_item_operations pci_primary_epc_item_ops = {
+	.allow_link	= pci_primary_epc_epf_link,
+	.drop_link	= pci_primary_epc_epf_unlink,
+};
+
+static const struct config_item_type pci_primary_epc_type = {
+	.ct_item_ops	= &pci_primary_epc_item_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct config_group
+*pci_ep_cfs_add_primary_group(struct pci_epf_group *epf_group)
+{
+	struct config_group *primary_epc_group = &epf_group->primary_epc_group;
+
+	config_group_init_type_name(primary_epc_group, "primary",
+				    &pci_primary_epc_type);
+	configfs_register_group(&epf_group->group, primary_epc_group);
+
+	return primary_epc_group;
+}
+
+static ssize_t pci_epc_start_store(struct config_item *item, const char *page,
+				   size_t len)
+{
+	int ret;
+	bool start;
+	struct pci_epc *epc;
+	struct pci_epc_group *epc_group = to_pci_epc_group(item);
+
+	epc = epc_group->epc;
+
+	if (kstrtobool(page, &start) < 0)
+		return -EINVAL;
+
+	if (start == epc_group->start)
+		return -EALREADY;
+
+	if (!start) {
+		pci_epc_stop(epc);
+		epc_group->start = 0;
+		return len;
+	}
+
+	ret = pci_epc_start(epc);
+	if (ret) {
+		dev_err(&epc->dev, "failed to start endpoint controller\n");
+		return -EINVAL;
+	}
+
+	epc_group->start = start;
+
+	return len;
+}
+
+static ssize_t pci_epc_start_show(struct config_item *item, char *page)
+{
+	return sysfs_emit(page, "%d\n", to_pci_epc_group(item)->start);
+}
+
+CONFIGFS_ATTR(pci_epc_, start);
+
+static struct configfs_attribute *pci_epc_attrs[] = {
+	&pci_epc_attr_start,
+	NULL,
+};
+
+static int pci_epc_epf_link(struct config_item *epc_item,
+			    struct config_item *epf_item)
+{
+	int ret;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
+
+	ret = pci_epc_add_epf(epc, epf, PRIMARY_INTERFACE);
+	if (ret)
+		return ret;
+
+	ret = pci_epf_bind(epf);
+	if (ret) {
+		pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void pci_epc_epf_unlink(struct config_item *epc_item,
+			       struct config_item *epf_item)
+{
+	struct pci_epc *epc;
+	struct pci_epf *epf;
+	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);
+	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
+
+	WARN_ON_ONCE(epc_group->start);
+
+	epc = epc_group->epc;
+	epf = epf_group->epf;
+	pci_epf_unbind(epf);
+	pci_epc_remove_epf(epc, epf, PRIMARY_INTERFACE);
+}
+
+static struct configfs_item_operations pci_epc_item_ops = {
+	.allow_link	= pci_epc_epf_link,
+	.drop_link	= pci_epc_epf_unlink,
+};
+
+static const struct config_item_type pci_epc_type = {
+	.ct_item_ops	= &pci_epc_item_ops,
+	.ct_attrs	= pci_epc_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct config_group *pci_ep_cfs_add_epc_group(const char *name)
+{
+	int ret;
+	struct pci_epc *epc;
+	struct config_group *group;
+	struct pci_epc_group *epc_group;
+
+	epc_group = kzalloc(sizeof(*epc_group), GFP_KERNEL);
+	if (!epc_group) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	group = &epc_group->group;
+
+	config_group_init_type_name(group, name, &pci_epc_type);
+	ret = configfs_register_group(controllers_group, group);
+	if (ret) {
+		pr_err("failed to register configfs group for %s\n", name);
+		goto err_register_group;
+	}
+
+	epc = pci_epc_get(name);
+	if (IS_ERR(epc)) {
+		ret = PTR_ERR(epc);
+		goto err_epc_get;
+	}
+
+	epc_group->epc = epc;
+
+	return group;
+
+err_epc_get:
+	configfs_unregister_group(group);
+
+err_register_group:
+	kfree(epc_group);
+
+err:
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(pci_ep_cfs_add_epc_group);
+
+void pci_ep_cfs_remove_epc_group(struct config_group *group)
+{
+	struct pci_epc_group *epc_group;
+
+	if (!group)
+		return;
+
+	epc_group = container_of(group, struct pci_epc_group, group);
+	pci_epc_put(epc_group->epc);
+	configfs_unregister_group(&epc_group->group);
+	kfree(epc_group);
+}
+EXPORT_SYMBOL(pci_ep_cfs_remove_epc_group);
+
+#define PCI_EPF_HEADER_R(_name)						       \
+static ssize_t pci_epf_##_name##_show(struct config_item *item,	char *page)    \
+{									       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	return sysfs_emit(page, "0x%04x\n", epf->header->_name);	       \
+}
+
+#define PCI_EPF_HEADER_W_u32(_name)					       \
+static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \
+				       const char *page, size_t len)	       \
+{									       \
+	u32 val;							       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	if (kstrtou32(page, 0, &val) < 0)				       \
+		return -EINVAL;						       \
+	epf->header->_name = val;					       \
+	return len;							       \
+}
+
+#define PCI_EPF_HEADER_W_u16(_name)					       \
+static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \
+				       const char *page, size_t len)	       \
+{									       \
+	u16 val;							       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	if (kstrtou16(page, 0, &val) < 0)				       \
+		return -EINVAL;						       \
+	epf->header->_name = val;					       \
+	return len;							       \
+}
+
+#define PCI_EPF_HEADER_W_u8(_name)					       \
+static ssize_t pci_epf_##_name##_store(struct config_item *item,	       \
+				       const char *page, size_t len)	       \
+{									       \
+	u8 val;								       \
+	struct pci_epf *epf = to_pci_epf_group(item)->epf;		       \
+	if (WARN_ON_ONCE(!epf->header))					       \
+		return -EINVAL;						       \
+	if (kstrtou8(page, 0, &val) < 0)				       \
+		return -EINVAL;						       \
+	epf->header->_name = val;					       \
+	return len;							       \
+}
+
+static ssize_t pci_epf_msi_interrupts_store(struct config_item *item,
+					    const char *page, size_t len)
+{
+	u8 val;
+
+	if (kstrtou8(page, 0, &val) < 0)
+		return -EINVAL;
+
+	to_pci_epf_group(item)->epf->msi_interrupts = val;
+
+	return len;
+}
+
+static ssize_t pci_epf_msi_interrupts_show(struct config_item *item,
+					   char *page)
+{
+	return sysfs_emit(page, "%d\n",
+			  to_pci_epf_group(item)->epf->msi_interrupts);
+}
+
+static ssize_t pci_epf_msix_interrupts_store(struct config_item *item,
+					     const char *page, size_t len)
+{
+	u16 val;
+
+	if (kstrtou16(page, 0, &val) < 0)
+		return -EINVAL;
+
+	to_pci_epf_group(item)->epf->msix_interrupts = val;
+
+	return len;
+}
+
+static ssize_t pci_epf_msix_interrupts_show(struct config_item *item,
+					    char *page)
+{
+	return sysfs_emit(page, "%d\n",
+			  to_pci_epf_group(item)->epf->msix_interrupts);
+}
+
+PCI_EPF_HEADER_R(vendorid)
+PCI_EPF_HEADER_W_u16(vendorid)
+
+PCI_EPF_HEADER_R(deviceid)
+PCI_EPF_HEADER_W_u16(deviceid)
+
+PCI_EPF_HEADER_R(revid)
+PCI_EPF_HEADER_W_u8(revid)
+
+PCI_EPF_HEADER_R(progif_code)
+PCI_EPF_HEADER_W_u8(progif_code)
+
+PCI_EPF_HEADER_R(subclass_code)
+PCI_EPF_HEADER_W_u8(subclass_code)
+
+PCI_EPF_HEADER_R(baseclass_code)
+PCI_EPF_HEADER_W_u8(baseclass_code)
+
+PCI_EPF_HEADER_R(cache_line_size)
+PCI_EPF_HEADER_W_u8(cache_line_size)
+
+PCI_EPF_HEADER_R(subsys_vendor_id)
+PCI_EPF_HEADER_W_u16(subsys_vendor_id)
+
+PCI_EPF_HEADER_R(subsys_id)
+PCI_EPF_HEADER_W_u16(subsys_id)
+
+PCI_EPF_HEADER_R(interrupt_pin)
+PCI_EPF_HEADER_W_u8(interrupt_pin)
+
+CONFIGFS_ATTR(pci_epf_, vendorid);
+CONFIGFS_ATTR(pci_epf_, deviceid);
+CONFIGFS_ATTR(pci_epf_, revid);
+CONFIGFS_ATTR(pci_epf_, progif_code);
+CONFIGFS_ATTR(pci_epf_, subclass_code);
+CONFIGFS_ATTR(pci_epf_, baseclass_code);
+CONFIGFS_ATTR(pci_epf_, cache_line_size);
+CONFIGFS_ATTR(pci_epf_, subsys_vendor_id);
+CONFIGFS_ATTR(pci_epf_, subsys_id);
+CONFIGFS_ATTR(pci_epf_, interrupt_pin);
+CONFIGFS_ATTR(pci_epf_, msi_interrupts);
+CONFIGFS_ATTR(pci_epf_, msix_interrupts);
+
+static struct configfs_attribute *pci_epf_attrs[] = {
+	&pci_epf_attr_vendorid,
+	&pci_epf_attr_deviceid,
+	&pci_epf_attr_revid,
+	&pci_epf_attr_progif_code,
+	&pci_epf_attr_subclass_code,
+	&pci_epf_attr_baseclass_code,
+	&pci_epf_attr_cache_line_size,
+	&pci_epf_attr_subsys_vendor_id,
+	&pci_epf_attr_subsys_id,
+	&pci_epf_attr_interrupt_pin,
+	&pci_epf_attr_msi_interrupts,
+	&pci_epf_attr_msix_interrupts,
+	NULL,
+};
+
+static int pci_epf_vepf_link(struct config_item *epf_pf_item,
+			     struct config_item *epf_vf_item)
+{
+	struct pci_epf_group *epf_vf_group = to_pci_epf_group(epf_vf_item);
+	struct pci_epf_group *epf_pf_group = to_pci_epf_group(epf_pf_item);
+	struct pci_epf *epf_pf = epf_pf_group->epf;
+	struct pci_epf *epf_vf = epf_vf_group->epf;
+
+	return pci_epf_add_vepf(epf_pf, epf_vf);
+}
+
+static void pci_epf_vepf_unlink(struct config_item *epf_pf_item,
+				struct config_item *epf_vf_item)
+{
+	struct pci_epf_group *epf_vf_group = to_pci_epf_group(epf_vf_item);
+	struct pci_epf_group *epf_pf_group = to_pci_epf_group(epf_pf_item);
+	struct pci_epf *epf_pf = epf_pf_group->epf;
+	struct pci_epf *epf_vf = epf_vf_group->epf;
+
+	pci_epf_remove_vepf(epf_pf, epf_vf);
+}
+
+static void pci_epf_release(struct config_item *item)
+{
+	struct pci_epf_group *epf_group = to_pci_epf_group(item);
+
+	mutex_lock(&functions_mutex);
+	idr_remove(&functions_idr, epf_group->index);
+	mutex_unlock(&functions_mutex);
+	pci_epf_destroy(epf_group->epf);
+	kfree(epf_group);
+}
+
+static struct configfs_item_operations pci_epf_ops = {
+	.allow_link		= pci_epf_vepf_link,
+	.drop_link		= pci_epf_vepf_unlink,
+	.release		= pci_epf_release,
+};
+
+static const struct config_item_type pci_epf_type = {
+	.ct_item_ops	= &pci_epf_ops,
+	.ct_attrs	= pci_epf_attrs,
+	.ct_owner	= THIS_MODULE,
+};
+
+/**
+ * pci_epf_type_add_cfs() - Help function drivers to expose function specific
+ *                          attributes in configfs
+ * @epf: the EPF device that has to be configured using configfs
+ * @group: the parent configfs group (corresponding to entries in
+ *         pci_epf_device_id)
+ *
+ * Invoke to expose function specific attributes in configfs.
+ *
+ * Return: A pointer to a config_group structure or NULL if the function driver
+ * does not have anything to expose (attributes configured by user) or if
+ * the function driver does not implement the add_cfs() method.
+ *
+ * Returns an error pointer if this function is called for an unbound EPF device
+ * or if the EPF driver add_cfs() method fails.
+ */
+static struct config_group *pci_epf_type_add_cfs(struct pci_epf *epf,
+						 struct config_group *group)
+{
+	struct config_group *epf_type_group;
+
+	if (!epf->driver) {
+		dev_err(&epf->dev, "epf device not bound to driver\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	if (!epf->driver->ops->add_cfs)
+		return NULL;
+
+	mutex_lock(&epf->lock);
+	epf_type_group = epf->driver->ops->add_cfs(epf, group);
+	mutex_unlock(&epf->lock);
+
+	return epf_type_group;
+}
+
+static void pci_ep_cfs_add_type_group(struct pci_epf_group *epf_group)
+{
+	struct config_group *group;
+
+	group = pci_epf_type_add_cfs(epf_group->epf, &epf_group->group);
+	if (!group)
+		return;
+
+	if (IS_ERR(group)) {
+		dev_err(&epf_group->epf->dev,
+			"failed to create epf type specific attributes\n");
+		return;
+	}
+
+	configfs_register_group(&epf_group->group, group);
+}
+
+static void pci_epf_cfs_work(struct work_struct *work)
+{
+	struct pci_epf_group *epf_group;
+	struct config_group *group;
+
+	epf_group = container_of(work, struct pci_epf_group, cfs_work.work);
+	group = pci_ep_cfs_add_primary_group(epf_group);
+	if (IS_ERR(group)) {
+		pr_err("failed to create 'primary' EPC interface\n");
+		return;
+	}
+
+	group = pci_ep_cfs_add_secondary_group(epf_group);
+	if (IS_ERR(group)) {
+		pr_err("failed to create 'secondary' EPC interface\n");
+		return;
+	}
+
+	pci_ep_cfs_add_type_group(epf_group);
+}
+
+static struct config_group *pci_epf_make(struct config_group *group,
+					 const char *name)
+{
+	struct pci_epf_group *epf_group;
+	struct pci_epf *epf;
+	char *epf_name;
+	int index, err;
+
+	epf_group = kzalloc(sizeof(*epf_group), GFP_KERNEL);
+	if (!epf_group)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&functions_mutex);
+	index = idr_alloc(&functions_idr, epf_group, 0, 0, GFP_KERNEL);
+	mutex_unlock(&functions_mutex);
+	if (index < 0) {
+		err = index;
+		goto free_group;
+	}
+
+	epf_group->index = index;
+
+	config_group_init_type_name(&epf_group->group, name, &pci_epf_type);
+
+	epf_name = kasprintf(GFP_KERNEL, "%s.%d",
+			     group->cg_item.ci_name, epf_group->index);
+	if (!epf_name) {
+		err = -ENOMEM;
+		goto remove_idr;
+	}
+
+	epf = pci_epf_create(epf_name);
+	if (IS_ERR(epf)) {
+		pr_err("failed to create endpoint function device\n");
+		err = -EINVAL;
+		goto free_name;
+	}
+
+	epf->group = &epf_group->group;
+	epf_group->epf = epf;
+
+	kfree(epf_name);
+
+	INIT_DELAYED_WORK(&epf_group->cfs_work, pci_epf_cfs_work);
+	queue_delayed_work(system_wq, &epf_group->cfs_work,
+			   msecs_to_jiffies(1));
+
+	return &epf_group->group;
+
+free_name:
+	kfree(epf_name);
+
+remove_idr:
+	mutex_lock(&functions_mutex);
+	idr_remove(&functions_idr, epf_group->index);
+	mutex_unlock(&functions_mutex);
+
+free_group:
+	kfree(epf_group);
+
+	return ERR_PTR(err);
+}
+
+static void pci_epf_drop(struct config_group *group, struct config_item *item)
+{
+	config_item_put(item);
+}
+
+static struct configfs_group_operations pci_epf_group_ops = {
+	.make_group     = &pci_epf_make,
+	.drop_item      = &pci_epf_drop,
+};
+
+static const struct config_item_type pci_epf_group_type = {
+	.ct_group_ops	= &pci_epf_group_ops,
+	.ct_owner	= THIS_MODULE,
+};
+
+struct config_group *pci_ep_cfs_add_epf_group(const char *name)
+{
+	struct config_group *group;
+
+	group = configfs_register_default_group(functions_group, name,
+						&pci_epf_group_type);
+	if (IS_ERR(group))
+		pr_err("failed to register configfs group for %s function\n",
+		       name);
+
+	return group;
+}
+EXPORT_SYMBOL(pci_ep_cfs_add_epf_group);
+
+void pci_ep_cfs_remove_epf_group(struct config_group *group)
+{
+	if (IS_ERR_OR_NULL(group))
+		return;
+
+	configfs_unregister_default_group(group);
+}
+EXPORT_SYMBOL(pci_ep_cfs_remove_epf_group);
+
+static const struct config_item_type pci_functions_type = {
+	.ct_owner	= THIS_MODULE,
+};
+
+static const struct config_item_type pci_controllers_type = {
+	.ct_owner	= THIS_MODULE,
+};
+
+static const struct config_item_type pci_ep_type = {
+	.ct_owner	= THIS_MODULE,
+};
+
+static struct configfs_subsystem pci_ep_cfs_subsys = {
+	.su_group = {
+		.cg_item = {
+			.ci_namebuf = "pci_ep",
+			.ci_type = &pci_ep_type,
+		},
+	},
+	.su_mutex = __MUTEX_INITIALIZER(pci_ep_cfs_subsys.su_mutex),
+};
+
+static int __init pci_ep_cfs_init(void)
+{
+	int ret;
+	struct config_group *root = &pci_ep_cfs_subsys.su_group;
+
+	config_group_init(root);
+
+	ret = configfs_register_subsystem(&pci_ep_cfs_subsys);
+	if (ret) {
+		pr_err("Error %d while registering subsystem %s\n",
+		       ret, root->cg_item.ci_namebuf);
+		goto err;
+	}
+
+	functions_group = configfs_register_default_group(root, "functions",
+							  &pci_functions_type);
+	if (IS_ERR(functions_group)) {
+		ret = PTR_ERR(functions_group);
+		pr_err("Error %d while registering functions group\n",
+		       ret);
+		goto err_functions_group;
+	}
+
+	controllers_group =
+		configfs_register_default_group(root, "controllers",
+						&pci_controllers_type);
+	if (IS_ERR(controllers_group)) {
+		ret = PTR_ERR(controllers_group);
+		pr_err("Error %d while registering controllers group\n",
+		       ret);
+		goto err_controllers_group;
+	}
+
+	return 0;
+
+err_controllers_group:
+	configfs_unregister_default_group(functions_group);
+
+err_functions_group:
+	configfs_unregister_subsystem(&pci_ep_cfs_subsys);
+
+err:
+	return ret;
+}
+module_init(pci_ep_cfs_init);
+
+static void __exit pci_ep_cfs_exit(void)
+{
+	configfs_unregister_default_group(controllers_group);
+	configfs_unregister_default_group(functions_group);
+	configfs_unregister_subsystem(&pci_ep_cfs_subsys);
+}
+module_exit(pci_ep_cfs_exit);
+
+MODULE_DESCRIPTION("PCI EP CONFIGFS");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");