diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
index 2c562b9eaf80..6a653e1a1acb 100644
--- a/drivers/pci/devres.c
+++ b/drivers/pci/devres.c
@@ -8,10 +8,215 @@
  */
 #define PCIM_IOMAP_MAX	PCI_STD_NUM_BARS
 
+/*
+ * Legacy struct storing addresses to whole mapped BARs.
+ */
 struct pcim_iomap_devres {
 	void __iomem *table[PCIM_IOMAP_MAX];
 };
 
+enum pcim_addr_devres_type {
+	/* Default initializer. */
+	PCIM_ADDR_DEVRES_TYPE_INVALID,
+
+	/* A region spanning an entire BAR. */
+	PCIM_ADDR_DEVRES_TYPE_REGION,
+
+	/* A region spanning an entire BAR, and a mapping for that whole 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,
+
+	/* A ranged region within a BAR, with a mapping spanning that range. */
+	PCIM_ADDR_DEVRES_TYPE_REGION_RANGE_MAPPING
+};
+
+/*
+ * This struct envelopes IO or MEM addresses, that means 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;
+	short bar;
+};
+
+static inline void pcim_addr_devres_clear(struct pcim_addr_devres *res)
+{
+	memset(res, 0, sizeof(*res));
+	res->bar = -1;
+}
+
+/*
+ * The following functions, __pcim_*_region*, exist as counterparts to the
+ * versions from pci.c - which, unfortunately, can be in "hybrid mode", i.e.,
+ * sometimes managed, sometimes not.
+ *
+ * To separate the APIs cleanly, we define our own, simplified versions here.
+ */
+
+/**
+ * __pcim_request_region_range - Request a ranged region
+ * @pdev: PCI device the region belongs to
+ * @bar: The BAR the region is within
+ * @offset: offset from the BAR's start address
+ * @maxlen: length in bytes, beginning at @offset
+ * @name: name associated with the request
+ * @req_flags: flags for the request. For example for kernel-exclusive requests.
+ *
+ * Returns: 0 on success, a negative error code on failure.
+ *
+ * Request a ranged region within a device's PCI BAR. This function performs
+ * sanity checks on the input.
+ */
+static int __pcim_request_region_range(struct pci_dev *pdev, int bar,
+		unsigned long offset, unsigned long maxlen,
+		const char *name, int req_flags)
+{
+	resource_size_t start = pci_resource_start(pdev, bar);
+	resource_size_t len = pci_resource_len(pdev, bar);
+	unsigned long dev_flags = pci_resource_flags(pdev, bar);
+
+	if (start == 0 || len == 0) /* That's an unused BAR. */
+		return 0;
+	if (len <= offset)
+		return  -EINVAL;
+
+	start += offset;
+	len -= offset;
+
+	if (len > maxlen && maxlen != 0)
+		len = maxlen;
+
+	if (dev_flags & IORESOURCE_IO) {
+		if (!request_region(start, len, name))
+			return -EBUSY;
+	} else if (dev_flags & IORESOURCE_MEM) {
+		if (!__request_mem_region(start, len, name, req_flags))
+			return -EBUSY;
+	} else {
+		/* That's not a device we can request anything on. */
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void __pcim_release_region_range(struct pci_dev *pdev, int bar,
+		unsigned long offset, unsigned long maxlen)
+{
+	resource_size_t start = pci_resource_start(pdev, bar);
+	resource_size_t len = pci_resource_len(pdev, bar);
+	unsigned long flags = pci_resource_flags(pdev, bar);
+
+	if (len <= offset || start == 0)
+		return;
+
+	if (len == 0 || maxlen == 0) /* This an unused BAR. Do nothing. */
+		return;
+
+	start += offset;
+	len -= offset;
+
+	if (len > maxlen)
+		len = maxlen;
+
+	if (flags & IORESOURCE_IO)
+		release_region(start, len);
+	else if (flags & IORESOURCE_MEM)
+		release_mem_region(start, len);
+}
+
+static int __pcim_request_region(struct pci_dev *pdev, int bar,
+		const char *name, int flags)
+{
+	unsigned long offset = 0;
+	unsigned long len = pci_resource_len(pdev, bar);
+
+	return __pcim_request_region_range(pdev, bar, offset, len, name, flags);
+}
+
+static void __pcim_release_region(struct pci_dev *pdev, int bar)
+{
+	unsigned long offset = 0;
+	unsigned long len = pci_resource_len(pdev, bar);
+
+	__pcim_release_region_range(pdev, bar, offset, len);
+}
+
+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:
+		__pcim_release_region(pdev, res->bar);
+		break;
+	case PCIM_ADDR_DEVRES_TYPE_REGION_MAPPING:
+		pci_iounmap(pdev, res->baseaddr);
+		__pcim_release_region(pdev, res->bar);
+		break;
+	case PCIM_ADDR_DEVRES_TYPE_MAPPING:
+		pci_iounmap(pdev, res->baseaddr);
+		break;
+	case PCIM_ADDR_DEVRES_TYPE_REGION_RANGE_MAPPING:
+		pci_iounmap(pdev, res->baseaddr);
+		__pcim_release_region_range(pdev, res->bar, res->offset, res->len);
+		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;
+	case PCIM_ADDR_DEVRES_TYPE_REGION_RANGE_MAPPING:
+		return a->bar == b->bar && a->offset == b->offset && a->len == b->len;
+	default:
+		return 0;
+	}
+}
 
 static void devm_pci_unmap_iospace(struct device *dev, void *ptr)
 {
@@ -92,8 +297,8 @@ EXPORT_SYMBOL(devm_pci_remap_cfgspace);
  *
  * All operations are managed and will be undone on driver detach.
  *
- * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
- * on failure. Usage example::
+ * 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);
@@ -339,15 +544,80 @@ void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
 			tbl[i] = NULL;
 			return;
 		}
-	WARN_ON(1);
 }
 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 associated with the request
+ *
+ * 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;
+
+	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 = __pcim_request_region(pdev, bar, name, 0);
+	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:
+	__pcim_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
  * @pdev: PCI device to map IO resources for
  * @mask: Mask of BARs to request and iomap
- * @name: Name used when requesting regions
+ * @name: Name associated with the requests
  *
  * Request and iomap regions specified by @mask.
  */
@@ -400,7 +670,7 @@ 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
+ * @name: Name associated with the requests
  *
  * Request all PCI BARs and iomap regions specified by @mask.
  */
@@ -446,3 +716,196 @@ void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
 	}
 }
 EXPORT_SYMBOL(pcim_iounmap_regions);
+
+static int _pcim_request_region(struct pci_dev *pdev, int bar, const char *name,
+		int request_flags)
+{
+	int ret;
+	struct pcim_addr_devres *res;
+
+	res = pcim_addr_devres_alloc(pdev);
+	if (!res)
+		return -ENOMEM;
+	res->type = PCIM_ADDR_DEVRES_TYPE_REGION;
+	res->bar = bar;
+
+	ret = __pcim_request_region(pdev, bar, name, request_flags);
+	if (ret != 0) {
+		pcim_addr_devres_free(res);
+		return ret;
+	}
+
+	devres_add(&pdev->dev, res);
+	return 0;
+}
+
+/**
+ * pcim_request_region - Request a PCI BAR
+ * @pdev: PCI device to requestion region for
+ * @bar: Index of BAR to request
+ * @name: Name associated with the request
+ *
+ * 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)
+{
+	return _pcim_request_region(pdev, bar, name, 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().
+ */
+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);
+}
+EXPORT_SYMBOL(pcim_release_region);
+
+/**
+ * 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;
+
+	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);
+
+/**
+ * pcim_iomap_region_range - Request and map a range within a PCI BAR
+ * @pdev: PCI device to map IO resources for
+ * @bar: Index of BAR to request within
+ * @offset: Offset from the begin of the BAR
+ * @len: Length in bytes for the mapping
+ * @name: Name associated with the request
+ *
+ * Returns: __iomem pointer on success, an IOMEM_ERR_PTR on failure.
+ *
+ * Request region with a range specified by @offset and @len within @bar and
+ * iomap it.
+ *
+ * The region will automatically be released and the mapping be unmapped on
+ * driver detach. If desired, release manually only with
+ * pcim_iounmap_region_range().
+ *
+ * You probably should only use this function if you explicitly do not want to
+ * request the entire BAR. For most use-cases, combining pcim_request_region()
+ * and pcim_iomap_range() should be sufficient.
+ */
+void __iomem *pcim_iomap_region_range(struct pci_dev *pdev, int bar,
+		unsigned long offset, unsigned long len, const char *name)
+{
+	int ret;
+	struct pcim_addr_devres *res;
+
+	res = pcim_addr_devres_alloc(pdev);
+	if (!res)
+		return IOMEM_ERR_PTR(-ENOMEM);
+
+	res->type = PCIM_ADDR_DEVRES_TYPE_REGION_RANGE_MAPPING;
+	res->bar = bar;
+	res->offset = offset;
+	res->len = len;
+
+	ret = __pcim_request_region_range(pdev, bar, offset, len, name, 0);
+	if (ret != 0)
+		goto err_region;
+
+	res->baseaddr = pci_iomap_range(pdev, bar, offset, len);
+	if (!res->baseaddr) {
+		ret = -EINVAL;
+		goto err_iomap;
+	}
+
+	devres_add(&pdev->dev, res);
+	return res->baseaddr;
+
+err_iomap:
+	__pcim_release_region_range(pdev, bar, offset, len);
+err_region:
+	pcim_addr_devres_free(res);
+
+	return IOMEM_ERR_PTR(ret);
+}
+EXPORT_SYMBOL(pcim_iomap_region_range);
+
+/**
+ * pcim_iounmap_region_range - Unmap and release a range within a PCI BAR
+ * @pdev: PCI device to operate on
+ * @bar: Index of BAR containing the range
+ * @offset: Offset from the begin of the BAR
+ * @len: Length in bytes for the mapping
+ *
+ * Unmaps and releases a memory area within the specified PCI BAR.
+ *
+ * This function may not be used to free only part of a range. Only use this
+ * function with the exact parameters you previously used successfully in
+ * pcim_iomap_region_range().
+ */
+void pcim_iounmap_region_range(struct pci_dev *pdev, int bar,
+		unsigned long offset, unsigned long len)
+{
+	struct pcim_addr_devres res_searched;
+	pcim_addr_devres_clear(&res_searched);
+
+	res_searched.type = PCIM_ADDR_DEVRES_TYPE_REGION_RANGE_MAPPING;
+	res_searched.bar = bar;
+	res_searched.offset = offset;
+	res_searched.len = len;
+
+	devres_release(&pdev->dev, pcim_addr_resource_release,
+			pcim_addr_resources_match, &res_searched);
+}
+EXPORT_SYMBOL(pcim_iounmap_region_range);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index a7cd31906547..764aef7023e8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2323,10 +2323,21 @@ static inline void pci_fixup_device(enum pci_fixup_pass pass,
 void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);
 void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr);
 void __iomem * const *pcim_iomap_table(struct pci_dev *pdev);
+void __iomem *pcim_iomap_region(struct pci_dev *pdev, int bar, const char *name);
+void pcim_iounmap_region(struct pci_dev *pdev, int bar);
 int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name);
 int pcim_iomap_regions_request_all(struct pci_dev *pdev, int mask,
 				   const char *name);
 void pcim_iounmap_regions(struct pci_dev *pdev, int mask);
+int pcim_request_region(struct pci_dev *pdev, int bar, const char *res_name);
+void pcim_release_region(struct pci_dev *pdev, int bar);
+void __iomem *pcim_iomap_range(struct pci_dev *pdev, int bar,
+				unsigned long offset, unsigned long len);
+void __iomem *pcim_iomap_region_range(struct pci_dev *pdev, int bar,
+				       unsigned long offset, unsigned long len,
+				       const char *res_name);
+void pcim_iounmap_region_range(struct pci_dev *pdev, int bar,
+			       unsigned long offset, unsigned long len);
 
 extern int pci_pci_problems;
 #define PCIPCI_FAIL		1	/* No PCI PCI DMA */
