#include <linux/pci.h>
  #include <linux/io.h>

  #include <linux/gfp.h>

  #include <linux/module.h>

  void devm_ioremap_release(struct device *dev, void *res)

  {
  	iounmap(*(void __iomem **)res);
  }
  
  static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
  {
  	return *(void **)res == match_data;
  }
  
  /**
   * devm_ioremap - Managed ioremap()
   * @dev: Generic device to remap IO address for
   * @offset: BUS offset to map
   * @size: Size of map
   *
   * Managed ioremap().  Map is automatically unmapped on driver detach.
   */

  void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,

  			   unsigned long size)
  {
  	void __iomem **ptr, *addr;
  
  	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
  	if (!ptr)
  		return NULL;
  
  	addr = ioremap(offset, size);
  	if (addr) {
  		*ptr = addr;
  		devres_add(dev, ptr);
  	} else
  		devres_free(ptr);
  
  	return addr;
  }
  EXPORT_SYMBOL(devm_ioremap);
  
  /**
   * devm_ioremap_nocache - Managed ioremap_nocache()
   * @dev: Generic device to remap IO address for
   * @offset: BUS offset to map
   * @size: Size of map
   *
   * Managed ioremap_nocache().  Map is automatically unmapped on driver
   * detach.
   */

  void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,

  				   unsigned long size)
  {
  	void __iomem **ptr, *addr;
  
  	ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
  	if (!ptr)
  		return NULL;
  
  	addr = ioremap_nocache(offset, size);
  	if (addr) {
  		*ptr = addr;
  		devres_add(dev, ptr);
  	} else
  		devres_free(ptr);
  
  	return addr;
  }
  EXPORT_SYMBOL(devm_ioremap_nocache);
  
  /**
   * devm_iounmap - Managed iounmap()
   * @dev: Generic device to unmap for
   * @addr: Address to unmap
   *
   * Managed iounmap().  @addr must have been mapped using devm_ioremap*().
   */
  void devm_iounmap(struct device *dev, void __iomem *addr)
  {

  	WARN_ON(devres_destroy(dev, devm_ioremap_release, devm_ioremap_match,
  			       (void *)addr));

  	iounmap(addr);

  }
  EXPORT_SYMBOL(devm_iounmap);

  /**
   * devm_request_and_ioremap() - Check, request region, and ioremap resource
   * @dev: Generic device to handle the resource for
   * @res: resource to be handled
   *
   * Takes all necessary steps to ioremap a mem resource. Uses managed device, so
   * everything is undone on driver detach. Checks arguments, so you can feed
   * it the result from e.g. platform_get_resource() directly. Returns the
   * remapped pointer or NULL on error. Usage example:
   *
   *	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
   *	base = devm_request_and_ioremap(&pdev->dev, res);
   *	if (!base)
   *		return -EADDRNOTAVAIL;
   */
  void __iomem *devm_request_and_ioremap(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
  ");
  		return NULL;
  	}
  
  	size = resource_size(res);
  	name = res->name ?: dev_name(dev);
  
  	if (!devm_request_mem_region(dev, res->start, size, name)) {
  		dev_err(dev, "can't request region for resource %pR
  ", res);
  		return NULL;
  	}
  
  	if (res->flags & IORESOURCE_CACHEABLE)
  		dest_ptr = devm_ioremap(dev, res->start, size);
  	else
  		dest_ptr = devm_ioremap_nocache(dev, res->start, size);
  
  	if (!dest_ptr) {
  		dev_err(dev, "ioremap failed for resource %pR
  ", res);
  		devm_release_mem_region(dev, res->start, size);
  	}
  
  	return dest_ptr;
  }
  EXPORT_SYMBOL(devm_request_and_ioremap);

  #ifdef CONFIG_HAS_IOPORT
  /*
   * Generic iomap devres
   */
  static void devm_ioport_map_release(struct device *dev, void *res)
  {
  	ioport_unmap(*(void __iomem **)res);
  }
  
  static int devm_ioport_map_match(struct device *dev, void *res,
  				 void *match_data)
  {
  	return *(void **)res == match_data;
  }
  
  /**
   * devm_ioport_map - Managed ioport_map()
   * @dev: Generic device to map ioport for
   * @port: Port to map
   * @nr: Number of ports to map
   *
   * Managed ioport_map().  Map is automatically unmapped on driver
   * detach.
   */
  void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
  			       unsigned int nr)
  {
  	void __iomem **ptr, *addr;
  
  	ptr = devres_alloc(devm_ioport_map_release, sizeof(*ptr), GFP_KERNEL);
  	if (!ptr)
  		return NULL;
  
  	addr = ioport_map(port, nr);
  	if (addr) {
  		*ptr = addr;
  		devres_add(dev, ptr);
  	} else
  		devres_free(ptr);
  
  	return addr;
  }
  EXPORT_SYMBOL(devm_ioport_map);
  
  /**
   * devm_ioport_unmap - Managed ioport_unmap()
   * @dev: Generic device to unmap for
   * @addr: Address to unmap
   *
   * Managed ioport_unmap().  @addr must have been mapped using
   * devm_ioport_map().
   */
  void devm_ioport_unmap(struct device *dev, void __iomem *addr)
  {
  	ioport_unmap(addr);
  	WARN_ON(devres_destroy(dev, devm_ioport_map_release,
  			       devm_ioport_map_match, (void *)addr));
  }
  EXPORT_SYMBOL(devm_ioport_unmap);
  
  #ifdef CONFIG_PCI
  /*
   * PCI iomap devres
   */
  #define PCIM_IOMAP_MAX	PCI_ROM_RESOURCE
  
  struct pcim_iomap_devres {
  	void __iomem *table[PCIM_IOMAP_MAX];
  };
  
  static void pcim_iomap_release(struct device *gendev, void *res)
  {
  	struct pci_dev *dev = container_of(gendev, struct pci_dev, dev);
  	struct pcim_iomap_devres *this = res;
  	int i;
  
  	for (i = 0; i < PCIM_IOMAP_MAX; i++)
  		if (this->table[i])
  			pci_iounmap(dev, this->table[i]);
  }
  
  /**
   * pcim_iomap_table - access iomap allocation table
   * @pdev: PCI device to access iomap table for
   *
   * 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 succed once
   * allocated.
   */
  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(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL);
  	if (!new_dr)
  		return NULL;
  	dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
  	return dr->table;
  }
  EXPORT_SYMBOL(pcim_iomap_table);
  
  /**
   * pcim_iomap - Managed pcim_iomap()
   * @pdev: PCI device to iomap for
   * @bar: BAR to iomap
   * @maxlen: Maximum length of iomap
   *
   * Managed pci_iomap().  Map is automatically unmapped on driver
   * detach.
   */
  void __iomem * pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
  {
  	void __iomem **tbl;
  
  	BUG_ON(bar >= PCIM_IOMAP_MAX);
  
  	tbl = (void __iomem **)pcim_iomap_table(pdev);
  	if (!tbl || tbl[bar])	/* duplicate mappings not allowed */
  		return NULL;
  
  	tbl[bar] = pci_iomap(pdev, bar, maxlen);
  	return tbl[bar];
  }
  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 pcim_iomap().
   */
  void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
  {
  	void __iomem **tbl;
  	int i;
  
  	pci_iounmap(pdev, addr);
  
  	tbl = (void __iomem **)pcim_iomap_table(pdev);
  	BUG_ON(!tbl);
  
  	for (i = 0; i < PCIM_IOMAP_MAX; i++)
  		if (tbl[i] == addr) {
  			tbl[i] = NULL;
  			return;
  		}
  	WARN_ON(1);
  }
  EXPORT_SYMBOL(pcim_iounmap);
  
  /**
   * pcim_iomap_regions - Request and iomap PCI BARs
   * @pdev: PCI device to map IO resources for
   * @mask: Mask of BARs to request and iomap
   * @name: Name used when requesting regions
   *
   * Request and iomap regions specified by @mask.
   */

  int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)

  {
  	void __iomem * const *iomap;
  	int i, rc;
  
  	iomap = pcim_iomap_table(pdev);
  	if (!iomap)
  		return -ENOMEM;
  
  	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
  		unsigned long len;
  
  		if (!(mask & (1 << i)))
  			continue;
  
  		rc = -EINVAL;
  		len = pci_resource_len(pdev, i);
  		if (!len)
  			goto err_inval;
  
  		rc = pci_request_region(pdev, i, name);
  		if (rc)

  			goto err_inval;

  
  		rc = -ENOMEM;
  		if (!pcim_iomap(pdev, i, 0))

  			goto err_region;

  	}
  
  	return 0;

   err_region:
  	pci_release_region(pdev, i);
   err_inval:
  	while (--i >= 0) {

  		if (!(mask & (1 << i)))
  			continue;

  		pcim_iounmap(pdev, iomap[i]);
  		pci_release_region(pdev, i);
  	}
  
  	return rc;
  }
  EXPORT_SYMBOL(pcim_iomap_regions);

  
  /**

   * pcim_iomap_regions_request_all - Request all BARs and iomap specified ones
   * @pdev: PCI device to map IO resources for
   * @mask: Mask of BARs to iomap
   * @name: Name used when requesting regions
   *
   * Request all PCI BARs and iomap regions specified by @mask.
   */

  int pcim_iomap_regions_request_all(struct pci_dev *pdev, int mask,

  				   const char *name)
  {
  	int request_mask = ((1 << 6) - 1) & ~mask;
  	int rc;
  
  	rc = pci_request_selected_regions(pdev, request_mask, name);
  	if (rc)
  		return rc;
  
  	rc = pcim_iomap_regions(pdev, mask, name);
  	if (rc)
  		pci_release_selected_regions(pdev, request_mask);
  	return rc;
  }
  EXPORT_SYMBOL(pcim_iomap_regions_request_all);
  
  /**

   * pcim_iounmap_regions - Unmap and release PCI BARs
   * @pdev: PCI device to map IO resources for
   * @mask: Mask of BARs to unmap and release
   *

   * Unmap and release regions specified by @mask.

   */

  void pcim_iounmap_regions(struct pci_dev *pdev, int mask)

  {
  	void __iomem * const *iomap;
  	int i;
  
  	iomap = pcim_iomap_table(pdev);
  	if (!iomap)
  		return;
  
  	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
  		if (!(mask & (1 << i)))
  			continue;
  
  		pcim_iounmap(pdev, iomap[i]);
  		pci_release_region(pdev, i);
  	}
  }
  EXPORT_SYMBOL(pcim_iounmap_regions);

  #endif /* CONFIG_PCI */
  #endif /* CONFIG_HAS_IOPORT */