// SPDX-License-Identifier: GPL-2.0
#include <linux/device.h>
#include <linux/pci.h>
#include "pci.h"

/*
 * On the state of PCI's devres implementation:
 *
 * The older PCI devres API has one significant problem:
 *
 * It is very strongly tied to the statically allocated mapping table in struct
 * pcim_iomap_devres below. This is mostly solved in the sense of the pcim_
 * functions in this file providing things like ranged mapping by bypassing
 * this table, whereas the functions that were present in the old API still
 * enter the mapping addresses into the table for users of the old API.
 *
 * TODO:
 * Remove the legacy table entirely once all calls to pcim_iomap_table() in
 * the kernel have been removed.
 */

/*
 * Legacy struct storing addresses to whole mapped BARs.
 */
struct pcim_iomap_devres {
        void __iomem *table[PCI_NUM_RESOURCES];
};

/* Used to restore the old INTx state on driver detach. */
struct pcim_intx_devres {
        int orig_intx;
};

enum pcim_addr_devres_type {
        /* Default initializer. */
        PCIM_ADDR_DEVRES_TYPE_INVALID,

        /* A requested region spanning an entire BAR. */
        PCIM_ADDR_DEVRES_TYPE_REGION,

        /*
         * A requested region spanning an entire BAR, and a mapping for
         * the entire BAR.
         */
        PCIM_ADDR_DEVRES_TYPE_REGION_MAPPING,

        /*
         * A mapping within a BAR, either spanning the whole BAR or just a
         * range.  Without a requested region.
         */
        PCIM_ADDR_DEVRES_TYPE_MAPPING,
};

/*
 * This struct envelops IO or MEM addresses, i.e., mappings and region
 * requests, because those are very frequently requested and released
 * together.
 */
struct pcim_addr_devres {
        enum pcim_addr_devres_type type;
        void __iomem *baseaddr;
        unsigned long offset;
        unsigned long len;
        int bar;
};

static inline void pcim_addr_devres_clear(struct pcim_addr_devres *res)
{
        memset(res, 0, sizeof(*res));
        res->bar = -1;
}

static void pcim_addr_resource_release(struct device *dev, void *resource_raw)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        struct pcim_addr_devres *res = resource_raw;

        switch (res->type) {
        case PCIM_ADDR_DEVRES_TYPE_REGION:
                pci_release_region(pdev, res->bar);
                break;
        case PCIM_ADDR_DEVRES_TYPE_REGION_MAPPING:
                pci_iounmap(pdev, res->baseaddr);
                pci_release_region(pdev, res->bar);
                break;
        case PCIM_ADDR_DEVRES_TYPE_MAPPING:
                pci_iounmap(pdev, res->baseaddr);
                break;
        default:
                break;
        }
}

static struct pcim_addr_devres *pcim_addr_devres_alloc(struct pci_dev *pdev)
{
        struct pcim_addr_devres *res;

        res = devres_alloc_node(pcim_addr_resource_release, sizeof(*res),
                                GFP_KERNEL, dev_to_node(&pdev->dev));
        if (res)
                pcim_addr_devres_clear(res);
        return res;
}

/* Just for consistency and readability. */
static inline void pcim_addr_devres_free(struct pcim_addr_devres *res)
{
        devres_free(res);
}

/*
 * Used by devres to identify a pcim_addr_devres.
 */
static int pcim_addr_resources_match(struct device *dev,
                                     void *a_raw, void *b_raw)
{
        struct pcim_addr_devres *a, *b;

        a = a_raw;
        b = b_raw;

        if (a->type != b->type)
                return 0;

        switch (a->type) {
        case PCIM_ADDR_DEVRES_TYPE_REGION:
        case PCIM_ADDR_DEVRES_TYPE_REGION_MAPPING:
                return a->bar == b->bar;
        case PCIM_ADDR_DEVRES_TYPE_MAPPING:
                return a->baseaddr == b->baseaddr;
        default:
                return 0;
        }
}

static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
{
        struct resource **res = ptr;

        pci_unmap_iospace(*res);
}

/**
 * devm_pci_remap_iospace - Managed pci_remap_iospace()
 * @dev: Generic device to remap IO address for
 * @res: Resource describing the I/O space
 * @phys_addr: physical address of range to be mapped
 *
 * Managed pci_remap_iospace().  Map is automatically unmapped on driver
 * detach.
 */
int devm_pci_remap_iospace(struct device *dev, const struct resource *res,
                           phys_addr_t phys_addr)
{
        const struct resource **ptr;
        int error;

        ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL);
        if (!ptr)
                return -ENOMEM;

        error = pci_remap_iospace(res, phys_addr);
        if (error) {
                devres_free(ptr);
        } else  {
                *ptr = res;
                devres_add(dev, ptr);
        }

        return error;
}
EXPORT_SYMBOL(devm_pci_remap_iospace);

/**
 * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
 * @dev: Generic device to remap IO address for
 * @offset: Resource address to map
 * @size: Size of map
 *
 * Managed pci_remap_cfgspace().  Map is automatically unmapped on driver
 * detach.
 */
void __iomem *devm_pci_remap_cfgspace(struct device *dev,
                                      resource_size_t offset,
                                      resource_size_t size)
{
        void __iomem **ptr, *addr;

        ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
        if (!ptr)
                return NULL;

        addr = pci_remap_cfgspace(offset, size);
        if (addr) {
                *ptr = addr;
                devres_add(dev, ptr);
        } else
                devres_free(ptr);

        return addr;
}
EXPORT_SYMBOL(devm_pci_remap_cfgspace);

/**
 * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
 * @dev: generic device to handle the resource for
 * @res: configuration space resource to be handled
 *
 * Checks that a resource is a valid memory region, requests the memory
 * region and ioremaps with pci_remap_cfgspace() API that ensures the
 * proper PCI configuration space memory attributes are guaranteed.
 *
 * All operations are managed and will be undone on driver detach.
 *
 * Returns a pointer to the remapped memory or an IOMEM_ERR_PTR() encoded error
 * code on failure. Usage example::
 *
 *      res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 *      base = devm_pci_remap_cfg_resource(&pdev->dev, res);
 *      if (IS_ERR(base))
 *              return PTR_ERR(base);
 */
void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
                                          struct resource *res)
{
        resource_size_t size;
        const char *name;
        void __iomem *dest_ptr;

        BUG_ON(!dev);

        if (!res || resource_type(res) != IORESOURCE_MEM) {
                dev_err(dev, "invalid resource\n");
                return IOMEM_ERR_PTR(-EINVAL);
        }

        size = resource_size(res);

        if (res->name)
                name = devm_kasprintf(dev, GFP_KERNEL, "%s %s", dev_name(dev),
                                      res->name);
        else
                name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
        if (!name)
                return IOMEM_ERR_PTR(-ENOMEM);

        if (!devm_request_mem_region(dev, res->start, size, name)) {
                dev_err(dev, "can't request region for resource %pR\n", res);
                return IOMEM_ERR_PTR(-EBUSY);
        }

        dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size);
        if (!dest_ptr) {
                dev_err(dev, "ioremap failed for resource %pR\n", res);
                devm_release_mem_region(dev, res->start, size);
                dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
        }

        return dest_ptr;
}
EXPORT_SYMBOL(devm_pci_remap_cfg_resource);

static void __pcim_clear_mwi(void *pdev_raw)
{
        struct pci_dev *pdev = pdev_raw;

        pci_clear_mwi(pdev);
}

/**
 * pcim_set_mwi - a device-managed pci_set_mwi()
 * @pdev: the PCI device for which MWI is enabled
 *
 * Managed pci_set_mwi().
 *
 * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
 */
int pcim_set_mwi(struct pci_dev *pdev)
{
        int ret;

        ret = devm_add_action(&pdev->dev, __pcim_clear_mwi, pdev);
        if (ret != 0)
                return ret;

        ret = pci_set_mwi(pdev);
        if (ret != 0)
                devm_remove_action(&pdev->dev, __pcim_clear_mwi, pdev);

        return ret;
}
EXPORT_SYMBOL(pcim_set_mwi);

static inline bool mask_contains_bar(int mask, int bar)
{
        return mask & BIT(bar);
}

static void pcim_intx_restore(struct device *dev, void *data)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        struct pcim_intx_devres *res = data;

        pci_intx(pdev, res->orig_intx);
}

static void save_orig_intx(struct pci_dev *pdev, struct pcim_intx_devres *res)
{
        u16 pci_command;

        pci_read_config_word(pdev, PCI_COMMAND, &pci_command);
        res->orig_intx = !(pci_command & PCI_COMMAND_INTX_DISABLE);
}

/**
 * pcim_intx - managed pci_intx()
 * @pdev: the PCI device to operate on
 * @enable: boolean: whether to enable or disable PCI INTx
 *
 * Returns: 0 on success, -ENOMEM on error.
 *
 * Enable/disable PCI INTx for device @pdev.
 * Restore the original state on driver detach.
 */
int pcim_intx(struct pci_dev *pdev, int enable)
{
        struct pcim_intx_devres *res;
        struct device *dev = &pdev->dev;

        /*
         * pcim_intx() must only restore the INTx value that existed before the
         * driver was loaded, i.e., before it called pcim_intx() for the
         * first time.
         */
        res = devres_find(dev, pcim_intx_restore, NULL, NULL);
        if (!res) {
                res = devres_alloc(pcim_intx_restore, sizeof(*res), GFP_KERNEL);
                if (!res)
                        return -ENOMEM;

                save_orig_intx(pdev, res);
                devres_add(dev, res);
        }

        pci_intx(pdev, enable);

        return 0;
}
EXPORT_SYMBOL_GPL(pcim_intx);

static void pcim_disable_device(void *pdev_raw)
{
        struct pci_dev *pdev = pdev_raw;

        if (!pdev->pinned)
                pci_disable_device(pdev);

        pdev->is_managed = false;
}

/**
 * pcim_enable_device - Managed pci_enable_device()
 * @pdev: PCI device to be initialized
 *
 * Returns: 0 on success, negative error code on failure.
 *
 * Managed pci_enable_device(). Device will automatically be disabled on
 * driver detach.
 */
int pcim_enable_device(struct pci_dev *pdev)
{
        int ret;

        ret = devm_add_action(&pdev->dev, pcim_disable_device, pdev);
        if (ret != 0)
                return ret;

        /*
         * We prefer removing the action in case of an error over
         * devm_add_action_or_reset() because the latter could theoretically be
         * disturbed by users having pinned the device too soon.
         */
        ret = pci_enable_device(pdev);
        if (ret != 0) {
                devm_remove_action(&pdev->dev, pcim_disable_device, pdev);
                return ret;
        }

        pdev->is_managed = true;

        return ret;
}
EXPORT_SYMBOL(pcim_enable_device);

/**
 * pcim_pin_device - Pin managed PCI device
 * @pdev: PCI device to pin
 *
 * Pin managed PCI device @pdev. Pinned device won't be disabled on driver
 * detach. @pdev must have been enabled with pcim_enable_device().
 */
void pcim_pin_device(struct pci_dev *pdev)
{
        pdev->pinned = true;
}
EXPORT_SYMBOL(pcim_pin_device);

static void pcim_iomap_release(struct device *gendev, void *res)
{
        /*
         * Do nothing. This is legacy code.
         *
         * Cleanup of the mappings is now done directly through the callbacks
         * registered when creating them.
         */
}

/**
 * pcim_iomap_table - access iomap allocation table (DEPRECATED)
 * @pdev: PCI device to access iomap table for
 *
 * Returns:
 * Const pointer to array of __iomem pointers on success, NULL on failure.
 *
 * Access iomap allocation table for @dev.  If iomap table doesn't
 * exist and @pdev is managed, it will be allocated.  All iomaps
 * recorded in the iomap table are automatically unmapped on driver
 * detach.
 *
 * This function might sleep when the table is first allocated but can
 * be safely called without context and guaranteed to succeed once
 * allocated.
 *
 * This function is DEPRECATED. Do not use it in new code. Instead, obtain a
 * mapping's address directly from one of the pcim_* mapping functions. For
 * example:
 * void __iomem \*mappy = pcim_iomap(pdev, bar, length);
 */
void __iomem * const *pcim_iomap_table(struct pci_dev *pdev)
{
        struct pcim_iomap_devres *dr, *new_dr;

        dr = devres_find(&pdev->dev, pcim_iomap_release, NULL, NULL);
        if (dr)
                return dr->table;

        new_dr = devres_alloc_node(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL,
                                   dev_to_node(&pdev->dev));
        if (!new_dr)
                return NULL;
        dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
        return dr->table;
}
EXPORT_SYMBOL(pcim_iomap_table);

/*
 * Fill the legacy mapping-table, so that drivers using the old API can
 * still get a BAR's mapping address through pcim_iomap_table().
 */
static int pcim_add_mapping_to_legacy_table(struct pci_dev *pdev,
                                            void __iomem *mapping, int bar)
{
        void __iomem **legacy_iomap_table;

        if (!pci_bar_index_is_valid(bar))
                return -EINVAL;

        legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev);
        if (!legacy_iomap_table)
                return -ENOMEM;

        legacy_iomap_table[bar] = mapping;

        return 0;
}

/*
 * Remove a mapping. The table only contains whole-BAR mappings, so this will
 * never interfere with ranged mappings.
 */
static void pcim_remove_mapping_from_legacy_table(struct pci_dev *pdev,
                                                  void __iomem *addr)
{
        int bar;
        void __iomem **legacy_iomap_table;

        legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev);
        if (!legacy_iomap_table)
                return;

        for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
                if (legacy_iomap_table[bar] == addr) {
                        legacy_iomap_table[bar] = NULL;
                        return;
                }
        }
}

/*
 * The same as pcim_remove_mapping_from_legacy_table(), but identifies the
 * mapping by its BAR index.
 */
static void pcim_remove_bar_from_legacy_table(struct pci_dev *pdev, int bar)
{
        void __iomem **legacy_iomap_table;

        if (!pci_bar_index_is_valid(bar))
                return;

        legacy_iomap_table = (void __iomem **)pcim_iomap_table(pdev);
        if (!legacy_iomap_table)
                return;

        legacy_iomap_table[bar] = NULL;
}

/**
 * pcim_iomap - Managed pcim_iomap()
 * @pdev: PCI device to iomap for
 * @bar: BAR to iomap
 * @maxlen: Maximum length of iomap
 *
 * Returns: __iomem pointer on success, NULL on failure.
 *
 * Managed pci_iomap(). Map is automatically unmapped on driver detach. If
 * desired, unmap manually only with pcim_iounmap().
 *
 * This SHOULD only be used once per BAR.
 *
 * NOTE:
 * Contrary to the other pcim_* functions, this function does not return an
 * IOMEM_ERR_PTR() on failure, but a simple NULL. This is done for backwards
 * compatibility.
 */
void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
{
        void __iomem *mapping;
        struct pcim_addr_devres *res;

        if (!pci_bar_index_is_valid(bar))
                return NULL;

        res = pcim_addr_devres_alloc(pdev);
        if (!res)
                return NULL;
        res->type = PCIM_ADDR_DEVRES_TYPE_MAPPING;

        mapping = pci_iomap(pdev, bar, maxlen);
        if (!mapping)
                goto err_iomap;
        res->baseaddr = mapping;

        if (pcim_add_mapping_to_legacy_table(pdev, mapping, bar) != 0)
                goto err_table;

        devres_add(&pdev->dev, res);
        return mapping;

err_table:
        pci_iounmap(pdev, mapping);
err_iomap:
        pcim_addr_devres_free(res);
        return NULL;
}
EXPORT_SYMBOL(pcim_iomap);

/**
 * pcim_iounmap - Managed pci_iounmap()
 * @pdev: PCI device to iounmap for
 * @addr: Address to unmap
 *
 * Managed pci_iounmap(). @addr must have been mapped using a pcim_* mapping
 * function.
 */
void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
        struct pcim_addr_devres res_searched;

        pcim_addr_devres_clear(&res_searched);
        res_searched.type = PCIM_ADDR_DEVRES_TYPE_MAPPING;
        res_searched.baseaddr = addr;

        if (devres_release(&pdev->dev, pcim_addr_resource_release,
                        pcim_addr_resources_match, &res_searched) != 0) {
                /* Doesn't exist. User passed nonsense. */
                return;
        }

        pcim_remove_mapping_from_legacy_table(pdev, addr);
}
EXPORT_SYMBOL(pcim_iounmap);

/**
 * pcim_iomap_region - Request and iomap a PCI BAR
 * @pdev: PCI device to map IO resources for
 * @bar: Index of a BAR to map
 * @name: Name of the driver requesting the resource
 *
 * Returns: __iomem pointer on success, an IOMEM_ERR_PTR on failure.
 *
 * Mapping and region will get automatically released on driver detach. If
 * desired, release manually only with pcim_iounmap_region().
 */
void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar,
                                       const char *name)
{
        int ret;
        struct pcim_addr_devres *res;

        if (!pci_bar_index_is_valid(bar))
                return IOMEM_ERR_PTR(-EINVAL);

        res = pcim_addr_devres_alloc(pdev);
        if (!res)
                return IOMEM_ERR_PTR(-ENOMEM);

        res->type = PCIM_ADDR_DEVRES_TYPE_REGION_MAPPING;
        res->bar = bar;

        ret = pci_request_region(pdev, bar, name);
        if (ret != 0)
                goto err_region;

        res->baseaddr = pci_iomap(pdev, bar, 0);
        if (!res->baseaddr) {
                ret = -EINVAL;
                goto err_iomap;
        }

        devres_add(&pdev->dev, res);
        return res->baseaddr;

err_iomap:
        pci_release_region(pdev, bar);
err_region:
        pcim_addr_devres_free(res);

        return IOMEM_ERR_PTR(ret);
}
EXPORT_SYMBOL(pcim_iomap_region);

/**
 * pcim_iounmap_region - Unmap and release a PCI BAR
 * @pdev: PCI device to operate on
 * @bar: Index of BAR to unmap and release
 *
 * Unmap a BAR and release its region manually. Only pass BARs that were
 * previously mapped by pcim_iomap_region().
 */
void pcim_iounmap_region(struct pci_dev *pdev, int bar)
{
        struct pcim_addr_devres res_searched;

        pcim_addr_devres_clear(&res_searched);
        res_searched.type = PCIM_ADDR_DEVRES_TYPE_REGION_MAPPING;
        res_searched.bar = bar;

        devres_release(&pdev->dev, pcim_addr_resource_release,
                        pcim_addr_resources_match, &res_searched);
}
EXPORT_SYMBOL(pcim_iounmap_region);

/**
 * pcim_iomap_regions - Request and iomap PCI BARs (DEPRECATED)
 * @pdev: PCI device to map IO resources for
 * @mask: Mask of BARs to request and iomap
 * @name: Name of the driver requesting the resources
 *
 * Returns: 0 on success, negative error code on failure.
 *
 * Request and iomap regions specified by @mask.
 *
 * This function is DEPRECATED. Do not use it in new code.
 * Use pcim_iomap_region() instead.
 */
int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
{
        int ret;
        int bar;
        void __iomem *mapping;

        for (bar = 0; bar < DEVICE_COUNT_RESOURCE; bar++) {
                if (!mask_contains_bar(mask, bar))
                        continue;

                mapping = pcim_iomap_region(pdev, bar, name);
                if (IS_ERR(mapping)) {
                        ret = PTR_ERR(mapping);
                        goto err;
                }
                ret = pcim_add_mapping_to_legacy_table(pdev, mapping, bar);
                if (ret != 0)
                        goto err;
        }

        return 0;

err:
        while (--bar >= 0) {
                pcim_iounmap_region(pdev, bar);
                pcim_remove_bar_from_legacy_table(pdev, bar);
        }

        return ret;
}
EXPORT_SYMBOL(pcim_iomap_regions);

/**
 * pcim_request_region - Request a PCI BAR
 * @pdev: PCI device to request region for
 * @bar: Index of BAR to request
 * @name: Name of the driver requesting the resource
 *
 * Returns: 0 on success, a negative error code on failure.
 *
 * Request region specified by @bar.
 *
 * The region will automatically be released on driver detach. If desired,
 * release manually only with pcim_release_region().
 */
int pcim_request_region(struct pci_dev *pdev, int bar, const char *name)
{
        int ret;
        struct pcim_addr_devres *res;

        if (!pci_bar_index_is_valid(bar))
                return -EINVAL;

        res = pcim_addr_devres_alloc(pdev);
        if (!res)
                return -ENOMEM;
        res->type = PCIM_ADDR_DEVRES_TYPE_REGION;
        res->bar = bar;

        ret = pci_request_region(pdev, bar, name);
        if (ret != 0) {
                pcim_addr_devres_free(res);
                return ret;
        }

        devres_add(&pdev->dev, res);
        return 0;
}
EXPORT_SYMBOL(pcim_request_region);

/**
 * pcim_release_region - Release a PCI BAR
 * @pdev: PCI device to operate on
 * @bar: Index of BAR to release
 *
 * Release a region manually that was previously requested by
 * pcim_request_region().
 */
static void pcim_release_region(struct pci_dev *pdev, int bar)
{
        struct pcim_addr_devres res_searched;

        pcim_addr_devres_clear(&res_searched);
        res_searched.type = PCIM_ADDR_DEVRES_TYPE_REGION;
        res_searched.bar = bar;

        devres_release(&pdev->dev, pcim_addr_resource_release,
                        pcim_addr_resources_match, &res_searched);
}


/**
 * pcim_release_all_regions - Release all regions of a PCI-device
 * @pdev: the PCI device
 *
 * Release all regions previously requested through pcim_request_region()
 * or pcim_request_all_regions().
 *
 * Can be called from any context, i.e., not necessarily as a counterpart to
 * pcim_request_all_regions().
 */
static void pcim_release_all_regions(struct pci_dev *pdev)
{
        int bar;

        for (bar = 0; bar < PCI_STD_NUM_BARS; bar++)
                pcim_release_region(pdev, bar);
}

/**
 * pcim_request_all_regions - Request all regions
 * @pdev: PCI device to map IO resources for
 * @name: name of the driver requesting the resources
 *
 * Returns: 0 on success, negative error code on failure.
 *
 * Requested regions will automatically be released at driver detach. If
 * desired, release individual regions with pcim_release_region() or all of
 * them at once with pcim_release_all_regions().
 */
int pcim_request_all_regions(struct pci_dev *pdev, const char *name)
{
        int ret;
        int bar;

        for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
                ret = pcim_request_region(pdev, bar, name);
                if (ret != 0)
                        goto err;
        }

        return 0;

err:
        pcim_release_all_regions(pdev);

        return ret;
}
EXPORT_SYMBOL(pcim_request_all_regions);

/**
 * pcim_iomap_range - Create a ranged __iomap mapping within a PCI BAR
 * @pdev: PCI device to map IO resources for
 * @bar: Index of the BAR
 * @offset: Offset from the begin of the BAR
 * @len: Length in bytes for the mapping
 *
 * Returns: __iomem pointer on success, an IOMEM_ERR_PTR on failure.
 *
 * Creates a new IO-Mapping within the specified @bar, ranging from @offset to
 * @offset + @len.
 *
 * The mapping will automatically get unmapped on driver detach. If desired,
 * release manually only with pcim_iounmap().
 */
void __iomem *pcim_iomap_range(struct pci_dev *pdev, int bar,
                unsigned long offset, unsigned long len)
{
        void __iomem *mapping;
        struct pcim_addr_devres *res;

        if (!pci_bar_index_is_valid(bar))
                return IOMEM_ERR_PTR(-EINVAL);

        res = pcim_addr_devres_alloc(pdev);
        if (!res)
                return IOMEM_ERR_PTR(-ENOMEM);

        mapping = pci_iomap_range(pdev, bar, offset, len);
        if (!mapping) {
                pcim_addr_devres_free(res);
                return IOMEM_ERR_PTR(-EINVAL);
        }

        res->type = PCIM_ADDR_DEVRES_TYPE_MAPPING;
        res->baseaddr = mapping;

        /*
         * Ranged mappings don't get added to the legacy-table, since the table
         * only ever keeps track of whole BARs.
         */

        devres_add(&pdev->dev, res);
        return mapping;
}
EXPORT_SYMBOL(pcim_iomap_range);