tools/testing/nvdimm/test/iomap.c - linux-imx - Git at Google

 /*
  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  */
 #include <linux/memremap.h>
 #include <linux/rculist.h>
 #include <linux/export.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/pfn_t.h>
 #include <linux/acpi.h>
 #include <linux/io.h>
 #include <linux/mm.h>
 #include "nfit_test.h"

 static LIST_HEAD(iomap_head);

 static struct iomap_ops {
 	nfit_test_lookup_fn nfit_test_lookup;
 	nfit_test_evaluate_dsm_fn evaluate_dsm;
 	struct list_head list;
 } iomap_ops = {
 	.list = LIST_HEAD_INIT(iomap_ops.list),
 };

 void nfit_test_setup(nfit_test_lookup_fn lookup,
 		nfit_test_evaluate_dsm_fn evaluate)
 {
 	iomap_ops.nfit_test_lookup = lookup;
 	iomap_ops.evaluate_dsm = evaluate;
 	list_add_rcu(&iomap_ops.list, &iomap_head);
 }
 EXPORT_SYMBOL(nfit_test_setup);

 void nfit_test_teardown(void)
 {
 	list_del_rcu(&iomap_ops.list);
 	synchronize_rcu();
 }
 EXPORT_SYMBOL(nfit_test_teardown);

 static struct nfit_test_resource *__get_nfit_res(resource_size_t resource)
 {
 	struct iomap_ops *ops;

 	ops = list_first_or_null_rcu(&iomap_head, typeof(*ops), list);
 	if (ops)
 		return ops->nfit_test_lookup(resource);
 	return NULL;
 }

 struct nfit_test_resource *get_nfit_res(resource_size_t resource)
 {
 	struct nfit_test_resource *res;

 	rcu_read_lock();
 	res = __get_nfit_res(resource);
 	rcu_read_unlock();

 	return res;
 }
 EXPORT_SYMBOL(get_nfit_res);

 void __iomem *__nfit_test_ioremap(resource_size_t offset, unsigned long size,
 		void __iomem *(*fallback_fn)(resource_size_t, unsigned long))
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

 	if (nfit_res)
 		return (void __iomem *) nfit_res->buf + offset
 			- nfit_res->res.start;
 	return fallback_fn(offset, size);
 }

 void __iomem *__wrap_devm_ioremap_nocache(struct device *dev,
 		resource_size_t offset, unsigned long size)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

 	if (nfit_res)
 		return (void __iomem *) nfit_res->buf + offset
 			- nfit_res->res.start;
 	return devm_ioremap_nocache(dev, offset, size);
 }
 EXPORT_SYMBOL(__wrap_devm_ioremap_nocache);

 void *__wrap_devm_memremap(struct device *dev, resource_size_t offset,
 		size_t size, unsigned long flags)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

 	if (nfit_res)
 		return nfit_res->buf + offset - nfit_res->res.start;
 	return devm_memremap(dev, offset, size, flags);
 }
 EXPORT_SYMBOL(__wrap_devm_memremap);

 void *__wrap_devm_memremap_pages(struct device *dev, struct resource *res,
 		struct percpu_ref *ref, struct vmem_altmap *altmap)
 {
 	resource_size_t offset = res->start;
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

 	if (nfit_res)
 		return nfit_res->buf + offset - nfit_res->res.start;
 	return devm_memremap_pages(dev, res, ref, altmap);
 }
 EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages);

 pfn_t __wrap_phys_to_pfn_t(phys_addr_t addr, unsigned long flags)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res(addr);

 	if (nfit_res)
 		flags &= ~PFN_MAP;
         return phys_to_pfn_t(addr, flags);
 }
 EXPORT_SYMBOL(__wrap_phys_to_pfn_t);

 void *__wrap_memremap(resource_size_t offset, size_t size,
 		unsigned long flags)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

 	if (nfit_res)
 		return nfit_res->buf + offset - nfit_res->res.start;
 	return memremap(offset, size, flags);
 }
 EXPORT_SYMBOL(__wrap_memremap);

 void __wrap_devm_memunmap(struct device *dev, void *addr)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);

 	if (nfit_res)
 		return;
 	return devm_memunmap(dev, addr);
 }
 EXPORT_SYMBOL(__wrap_devm_memunmap);

 void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
 {
 	return __nfit_test_ioremap(offset, size, ioremap_nocache);
 }
 EXPORT_SYMBOL(__wrap_ioremap_nocache);

 void __iomem *__wrap_ioremap_wc(resource_size_t offset, unsigned long size)
 {
 	return __nfit_test_ioremap(offset, size, ioremap_wc);
 }
 EXPORT_SYMBOL(__wrap_ioremap_wc);

 void __wrap_iounmap(volatile void __iomem *addr)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);
 	if (nfit_res)
 		return;
 	return iounmap(addr);
 }
 EXPORT_SYMBOL(__wrap_iounmap);

 void __wrap_memunmap(void *addr)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);

 	if (nfit_res)
 		return;
 	return memunmap(addr);
 }
 EXPORT_SYMBOL(__wrap_memunmap);

 static bool nfit_test_release_region(struct device *dev,
 		struct resource *parent, resource_size_t start,
 		resource_size_t n);

 static void nfit_devres_release(struct device *dev, void *data)
 {
 	struct resource *res = *((struct resource **) data);

 	WARN_ON(!nfit_test_release_region(NULL, &iomem_resource, res->start,
 			resource_size(res)));
 }

 static int match(struct device *dev, void *__res, void *match_data)
 {
 	struct resource *res = *((struct resource **) __res);
 	resource_size_t start = *((resource_size_t *) match_data);

 	return res->start == start;
 }

 static bool nfit_test_release_region(struct device *dev,
 		struct resource *parent, resource_size_t start,
 		resource_size_t n)
 {
 	if (parent == &iomem_resource) {
 		struct nfit_test_resource *nfit_res = get_nfit_res(start);

 		if (nfit_res) {
 			struct nfit_test_request *req;
 			struct resource *res = NULL;

 			if (dev) {
 				devres_release(dev, nfit_devres_release, match,
 						&start);
 				return true;
 			}

 			spin_lock(&nfit_res->lock);
 			list_for_each_entry(req, &nfit_res->requests, list)
 				if (req->res.start == start) {
 					res = &req->res;
 					list_del(&req->list);
 					break;
 				}
 			spin_unlock(&nfit_res->lock);

 			WARN(!res || resource_size(res) != n,
 					"%s: start: %llx n: %llx mismatch: %pr\n",
 						__func__, start, n, res);
 			if (res)
 				kfree(req);
 			return true;
 		}
 	}
 	return false;
 }

 static struct resource *nfit_test_request_region(struct device *dev,
 		struct resource *parent, resource_size_t start,
 		resource_size_t n, const char *name, int flags)
 {
 	struct nfit_test_resource *nfit_res;

 	if (parent == &iomem_resource) {
 		nfit_res = get_nfit_res(start);
 		if (nfit_res) {
 			struct nfit_test_request *req;
 			struct resource *res = NULL;

 			if (start + n > nfit_res->res.start
 					+ resource_size(&nfit_res->res)) {
 				pr_debug("%s: start: %llx n: %llx overflow: %pr\n",
 						__func__, start, n,
 						&nfit_res->res);
 				return NULL;
 			}

 			spin_lock(&nfit_res->lock);
 			list_for_each_entry(req, &nfit_res->requests, list)
 				if (start == req->res.start) {
 					res = &req->res;
 					break;
 				}
 			spin_unlock(&nfit_res->lock);

 			if (res) {
 				WARN(1, "%pr already busy\n", res);
 				return NULL;
 			}

 			req = kzalloc(sizeof(*req), GFP_KERNEL);
 			if (!req)
 				return NULL;
 			INIT_LIST_HEAD(&req->list);
 			res = &req->res;

 			res->start = start;
 			res->end = start + n - 1;
 			res->name = name;
 			res->flags = resource_type(parent);
 			res->flags |= IORESOURCE_BUSY | flags;
 			spin_lock(&nfit_res->lock);
 			list_add(&req->list, &nfit_res->requests);
 			spin_unlock(&nfit_res->lock);

 			if (dev) {
 				struct resource **d;

 				d = devres_alloc(nfit_devres_release,
 						sizeof(struct resource *),
 						GFP_KERNEL);
 				if (!d)
 					return NULL;
 				*d = res;
 				devres_add(dev, d);
 			}

 			pr_debug("%s: %pr\n", __func__, res);
 			return res;
 		}
 	}
 	if (dev)
 		return __devm_request_region(dev, parent, start, n, name);
 	return __request_region(parent, start, n, name, flags);
 }

 struct resource *__wrap___request_region(struct resource *parent,
 		resource_size_t start, resource_size_t n, const char *name,
 		int flags)
 {
 	return nfit_test_request_region(NULL, parent, start, n, name, flags);
 }
 EXPORT_SYMBOL(__wrap___request_region);

 int __wrap_insert_resource(struct resource *parent, struct resource *res)
 {
 	if (get_nfit_res(res->start))
 		return 0;
 	return insert_resource(parent, res);
 }
 EXPORT_SYMBOL(__wrap_insert_resource);

 int __wrap_remove_resource(struct resource *res)
 {
 	if (get_nfit_res(res->start))
 		return 0;
 	return remove_resource(res);
 }
 EXPORT_SYMBOL(__wrap_remove_resource);

 struct resource *__wrap___devm_request_region(struct device *dev,
 		struct resource *parent, resource_size_t start,
 		resource_size_t n, const char *name)
 {
 	if (!dev)
 		return NULL;
 	return nfit_test_request_region(dev, parent, start, n, name, 0);
 }
 EXPORT_SYMBOL(__wrap___devm_request_region);

 void __wrap___release_region(struct resource *parent, resource_size_t start,
 		resource_size_t n)
 {
 	if (!nfit_test_release_region(NULL, parent, start, n))
 		__release_region(parent, start, n);
 }
 EXPORT_SYMBOL(__wrap___release_region);

 void __wrap___devm_release_region(struct device *dev, struct resource *parent,
 		resource_size_t start, resource_size_t n)
 {
 	if (!nfit_test_release_region(dev, parent, start, n))
 		__devm_release_region(dev, parent, start, n);
 }
 EXPORT_SYMBOL(__wrap___devm_release_region);

 acpi_status __wrap_acpi_evaluate_object(acpi_handle handle, acpi_string path,
 		struct acpi_object_list *p, struct acpi_buffer *buf)
 {
 	struct nfit_test_resource *nfit_res = get_nfit_res((long) handle);
 	union acpi_object **obj;

 	if (!nfit_res || strcmp(path, "_FIT") || !buf)
 		return acpi_evaluate_object(handle, path, p, buf);

 	obj = nfit_res->buf;
 	buf->length = sizeof(union acpi_object);
 	buf->pointer = *obj;
 	return AE_OK;
 }
 EXPORT_SYMBOL(__wrap_acpi_evaluate_object);

 union acpi_object * __wrap_acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid,
 		u64 rev, u64 func, union acpi_object *argv4)
 {
 	union acpi_object *obj = ERR_PTR(-ENXIO);
 	struct iomap_ops *ops;

 	rcu_read_lock();
 	ops = list_first_or_null_rcu(&iomap_head, typeof(*ops), list);
 	if (ops)
 		obj = ops->evaluate_dsm(handle, guid, rev, func, argv4);
 	rcu_read_unlock();

 	if (IS_ERR(obj))
 		return acpi_evaluate_dsm(handle, guid, rev, func, argv4);
 	return obj;
 }
 EXPORT_SYMBOL(__wrap_acpi_evaluate_dsm);

 MODULE_LICENSE("GPL v2");
	/*
	* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of version 2 of the GNU General Public License as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*/
	#include <linux/memremap.h>
	#include <linux/rculist.h>
	#include <linux/export.h>
	#include <linux/ioport.h>
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/pfn_t.h>
	#include <linux/acpi.h>
	#include <linux/io.h>
	#include <linux/mm.h>
	#include "nfit_test.h"

	static LIST_HEAD(iomap_head);

	static struct iomap_ops {
	nfit_test_lookup_fn nfit_test_lookup;
	nfit_test_evaluate_dsm_fn evaluate_dsm;
	struct list_head list;
	} iomap_ops = {
	.list = LIST_HEAD_INIT(iomap_ops.list),
	};

	void nfit_test_setup(nfit_test_lookup_fn lookup,
	nfit_test_evaluate_dsm_fn evaluate)
	{
	iomap_ops.nfit_test_lookup = lookup;
	iomap_ops.evaluate_dsm = evaluate;
	list_add_rcu(&iomap_ops.list, &iomap_head);
	}
	EXPORT_SYMBOL(nfit_test_setup);

	void nfit_test_teardown(void)
	{
	list_del_rcu(&iomap_ops.list);
	synchronize_rcu();
	}
	EXPORT_SYMBOL(nfit_test_teardown);

	static struct nfit_test_resource *__get_nfit_res(resource_size_t resource)
	{
	struct iomap_ops *ops;

	ops = list_first_or_null_rcu(&iomap_head, typeof(*ops), list);
	if (ops)
	return ops->nfit_test_lookup(resource);
	return NULL;
	}

	struct nfit_test_resource *get_nfit_res(resource_size_t resource)
	{
	struct nfit_test_resource *res;

	rcu_read_lock();
	res = __get_nfit_res(resource);
	rcu_read_unlock();

	return res;
	}
	EXPORT_SYMBOL(get_nfit_res);

	void __iomem *__nfit_test_ioremap(resource_size_t offset, unsigned long size,
	void __iomem (fallback_fn)(resource_size_t, unsigned long))
	{
	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

	if (nfit_res)
	return (void __iomem *) nfit_res->buf + offset
	- nfit_res->res.start;
	return fallback_fn(offset, size);
	}

	void __iomem __wrap_devm_ioremap_nocache(struct device dev,
	resource_size_t offset, unsigned long size)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

	if (nfit_res)
	return (void __iomem *) nfit_res->buf + offset
	- nfit_res->res.start;
	return devm_ioremap_nocache(dev, offset, size);
	}
	EXPORT_SYMBOL(__wrap_devm_ioremap_nocache);

	void __wrap_devm_memremap(struct device dev, resource_size_t offset,
	size_t size, unsigned long flags)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

	if (nfit_res)
	return nfit_res->buf + offset - nfit_res->res.start;
	return devm_memremap(dev, offset, size, flags);
	}
	EXPORT_SYMBOL(__wrap_devm_memremap);

	void __wrap_devm_memremap_pages(struct device dev, struct resource *res,
	struct percpu_ref ref, struct vmem_altmap altmap)
	{
	resource_size_t offset = res->start;
	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

	if (nfit_res)
	return nfit_res->buf + offset - nfit_res->res.start;
	return devm_memremap_pages(dev, res, ref, altmap);
	}
	EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages);

	pfn_t __wrap_phys_to_pfn_t(phys_addr_t addr, unsigned long flags)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res(addr);

	if (nfit_res)
	flags &= ~PFN_MAP;
	return phys_to_pfn_t(addr, flags);
	}
	EXPORT_SYMBOL(__wrap_phys_to_pfn_t);

	void *__wrap_memremap(resource_size_t offset, size_t size,
	unsigned long flags)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res(offset);

	if (nfit_res)
	return nfit_res->buf + offset - nfit_res->res.start;
	return memremap(offset, size, flags);
	}
	EXPORT_SYMBOL(__wrap_memremap);

	void __wrap_devm_memunmap(struct device dev, void addr)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);

	if (nfit_res)
	return;
	return devm_memunmap(dev, addr);
	}
	EXPORT_SYMBOL(__wrap_devm_memunmap);

	void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
	{
	return __nfit_test_ioremap(offset, size, ioremap_nocache);
	}
	EXPORT_SYMBOL(__wrap_ioremap_nocache);

	void __iomem *__wrap_ioremap_wc(resource_size_t offset, unsigned long size)
	{
	return __nfit_test_ioremap(offset, size, ioremap_wc);
	}
	EXPORT_SYMBOL(__wrap_ioremap_wc);

	void __wrap_iounmap(volatile void __iomem *addr)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);
	if (nfit_res)
	return;
	return iounmap(addr);
	}
	EXPORT_SYMBOL(__wrap_iounmap);

	void __wrap_memunmap(void *addr)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res((long) addr);

	if (nfit_res)
	return;
	return memunmap(addr);
	}
	EXPORT_SYMBOL(__wrap_memunmap);

	static bool nfit_test_release_region(struct device *dev,
	struct resource *parent, resource_size_t start,
	resource_size_t n);

	static void nfit_devres_release(struct device dev, void data)
	{
	struct resource res = ((struct resource **) data);

	WARN_ON(!nfit_test_release_region(NULL, &iomem_resource, res->start,
	resource_size(res)));
	}

	static int match(struct device dev, void __res, void *match_data)
	{
	struct resource res = ((struct resource **) __res);
	resource_size_t start = ((resource_size_t ) match_data);

	return res->start == start;
	}

	static bool nfit_test_release_region(struct device *dev,
	struct resource *parent, resource_size_t start,
	resource_size_t n)
	{
	if (parent == &iomem_resource) {
	struct nfit_test_resource *nfit_res = get_nfit_res(start);

	if (nfit_res) {
	struct nfit_test_request *req;
	struct resource *res = NULL;

	if (dev) {
	devres_release(dev, nfit_devres_release, match,
	&start);
	return true;
	}

	spin_lock(&nfit_res->lock);
	list_for_each_entry(req, &nfit_res->requests, list)
	if (req->res.start == start) {
	res = &req->res;
	list_del(&req->list);
	break;
	}
	spin_unlock(&nfit_res->lock);

	WARN(!res \|\| resource_size(res) != n,
	"%s: start: %llx n: %llx mismatch: %pr\n",
	__func__, start, n, res);
	if (res)
	kfree(req);
	return true;
	}
	}
	return false;
	}

	static struct resource nfit_test_request_region(struct device dev,
	struct resource *parent, resource_size_t start,
	resource_size_t n, const char *name, int flags)
	{
	struct nfit_test_resource *nfit_res;

	if (parent == &iomem_resource) {
	nfit_res = get_nfit_res(start);
	if (nfit_res) {
	struct nfit_test_request *req;
	struct resource *res = NULL;

	if (start + n > nfit_res->res.start
	+ resource_size(&nfit_res->res)) {
	pr_debug("%s: start: %llx n: %llx overflow: %pr\n",
	__func__, start, n,
	&nfit_res->res);
	return NULL;
	}

	spin_lock(&nfit_res->lock);
	list_for_each_entry(req, &nfit_res->requests, list)
	if (start == req->res.start) {
	res = &req->res;
	break;
	}
	spin_unlock(&nfit_res->lock);

	if (res) {
	WARN(1, "%pr already busy\n", res);
	return NULL;
	}

	req = kzalloc(sizeof(*req), GFP_KERNEL);
	if (!req)
	return NULL;
	INIT_LIST_HEAD(&req->list);
	res = &req->res;

	res->start = start;
	res->end = start + n - 1;
	res->name = name;
	res->flags = resource_type(parent);
	res->flags \|= IORESOURCE_BUSY \| flags;
	spin_lock(&nfit_res->lock);
	list_add(&req->list, &nfit_res->requests);
	spin_unlock(&nfit_res->lock);

	if (dev) {
	struct resource **d;

	d = devres_alloc(nfit_devres_release,
	sizeof(struct resource *),
	GFP_KERNEL);
	if (!d)
	return NULL;
	*d = res;
	devres_add(dev, d);
	}

	pr_debug("%s: %pr\n", __func__, res);
	return res;
	}
	}
	if (dev)
	return __devm_request_region(dev, parent, start, n, name);
	return __request_region(parent, start, n, name, flags);
	}

	struct resource __wrap___request_region(struct resource parent,
	resource_size_t start, resource_size_t n, const char *name,
	int flags)
	{
	return nfit_test_request_region(NULL, parent, start, n, name, flags);
	}
	EXPORT_SYMBOL(__wrap___request_region);

	int __wrap_insert_resource(struct resource parent, struct resource res)
	{
	if (get_nfit_res(res->start))
	return 0;
	return insert_resource(parent, res);
	}
	EXPORT_SYMBOL(__wrap_insert_resource);

	int __wrap_remove_resource(struct resource *res)
	{
	if (get_nfit_res(res->start))
	return 0;
	return remove_resource(res);
	}
	EXPORT_SYMBOL(__wrap_remove_resource);

	struct resource __wrap___devm_request_region(struct device dev,
	struct resource *parent, resource_size_t start,
	resource_size_t n, const char *name)
	{
	if (!dev)
	return NULL;
	return nfit_test_request_region(dev, parent, start, n, name, 0);
	}
	EXPORT_SYMBOL(__wrap___devm_request_region);

	void __wrap___release_region(struct resource *parent, resource_size_t start,
	resource_size_t n)
	{
	if (!nfit_test_release_region(NULL, parent, start, n))
	__release_region(parent, start, n);
	}
	EXPORT_SYMBOL(__wrap___release_region);

	void __wrap___devm_release_region(struct device dev, struct resource parent,
	resource_size_t start, resource_size_t n)
	{
	if (!nfit_test_release_region(dev, parent, start, n))
	__devm_release_region(dev, parent, start, n);
	}
	EXPORT_SYMBOL(__wrap___devm_release_region);

	acpi_status __wrap_acpi_evaluate_object(acpi_handle handle, acpi_string path,
	struct acpi_object_list p, struct acpi_buffer buf)
	{
	struct nfit_test_resource *nfit_res = get_nfit_res((long) handle);
	union acpi_object **obj;

	if (!nfit_res \|\| strcmp(path, "_FIT") \|\| !buf)
	return acpi_evaluate_object(handle, path, p, buf);

	obj = nfit_res->buf;
	buf->length = sizeof(union acpi_object);
	buf->pointer = *obj;
	return AE_OK;
	}
	EXPORT_SYMBOL(__wrap_acpi_evaluate_object);

	union acpi_object * __wrap_acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid,
	u64 rev, u64 func, union acpi_object *argv4)
	{
	union acpi_object *obj = ERR_PTR(-ENXIO);
	struct iomap_ops *ops;

	rcu_read_lock();
	ops = list_first_or_null_rcu(&iomap_head, typeof(*ops), list);
	if (ops)
	obj = ops->evaluate_dsm(handle, guid, rev, func, argv4);
	rcu_read_unlock();

	if (IS_ERR(obj))
	return acpi_evaluate_dsm(handle, guid, rev, func, argv4);
	return obj;
	}
	EXPORT_SYMBOL(__wrap_acpi_evaluate_dsm);

	MODULE_LICENSE("GPL v2");