root/tools/testing/nvdimm/test/iomap.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
 */
#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/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);

#define __nfit_test_ioremap(offset, size, fallback_fn) ({               \
        struct nfit_test_resource *nfit_res = get_nfit_res(offset);     \
        nfit_res ?                                                      \
                (void __iomem *) nfit_res->buf + (offset)               \
                        - nfit_res->res.start                           \
        :                                                               \
                fallback_fn((offset), (size)) ;                         \
})

void __iomem *__wrap_devm_ioremap(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(dev, offset, size);
}
EXPORT_SYMBOL(__wrap_devm_ioremap);

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);

static void nfit_test_kill(void *_pgmap)
{
        struct dev_pagemap *pgmap = _pgmap;

        WARN_ON(!pgmap);

        percpu_ref_kill(&pgmap->ref);

        wait_for_completion(&pgmap->done);
        percpu_ref_exit(&pgmap->ref);
}

static void dev_pagemap_percpu_release(struct percpu_ref *ref)
{
        struct dev_pagemap *pgmap = container_of(ref, struct dev_pagemap, ref);

        complete(&pgmap->done);
}

void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
        int error;
        resource_size_t offset = pgmap->range.start;
        struct nfit_test_resource *nfit_res = get_nfit_res(offset);

        if (!nfit_res)
                return devm_memremap_pages(dev, pgmap);

        init_completion(&pgmap->done);
        error = percpu_ref_init(&pgmap->ref, dev_pagemap_percpu_release, 0,
                                GFP_KERNEL);
        if (error)
                return ERR_PTR(error);

        error = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);
        if (error)
                return ERR_PTR(error);
        return nfit_res->buf + offset - nfit_res->res.start;
}
EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages);

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(resource_size_t offset, unsigned long size)
{
        return __nfit_test_ioremap(offset, size, ioremap);
}
EXPORT_SYMBOL(__wrap_ioremap);

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_DESCRIPTION("NVDIMM unit test");
MODULE_LICENSE("GPL v2");