mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 06:05:15 +07:00
7ae731a844
We recently introduced a bug when we tried to convert of_iomap() to devm_of_iomap(). The problem was that there were two drivers mapping the same io region. The first driver was using of_iomap() and the second driver was using devm_of_iomap() and the kernel booted fine. When we converted the first drive to use devm_of_iomap() then the second driver failed with -EBUSY and the kernel couldn't boot. Let's add a comment to prevent this sort of mistake in the future. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20200609104642.GA43074@mwanda Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
501 lines
12 KiB
C
501 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/err.h>
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#include <linux/pci.h>
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#include <linux/io.h>
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#include <linux/gfp.h>
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#include <linux/export.h>
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#include <linux/of_address.h>
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enum devm_ioremap_type {
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DEVM_IOREMAP = 0,
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DEVM_IOREMAP_UC,
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DEVM_IOREMAP_WC,
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};
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void devm_ioremap_release(struct device *dev, void *res)
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{
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iounmap(*(void __iomem **)res);
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}
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static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
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{
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return *(void **)res == match_data;
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}
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static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset,
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resource_size_t size,
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enum devm_ioremap_type type)
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{
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void __iomem **ptr, *addr = NULL;
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ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL);
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if (!ptr)
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return NULL;
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switch (type) {
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case DEVM_IOREMAP:
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addr = ioremap(offset, size);
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break;
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case DEVM_IOREMAP_UC:
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addr = ioremap_uc(offset, size);
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break;
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case DEVM_IOREMAP_WC:
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addr = ioremap_wc(offset, size);
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break;
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}
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if (addr) {
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*ptr = addr;
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devres_add(dev, ptr);
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} else
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devres_free(ptr);
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return addr;
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}
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/**
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* devm_ioremap - Managed ioremap()
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* @dev: Generic device to remap IO address for
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* @offset: Resource address to map
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* @size: Size of map
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*
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* Managed ioremap(). Map is automatically unmapped on driver detach.
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*/
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void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
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resource_size_t size)
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{
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return __devm_ioremap(dev, offset, size, DEVM_IOREMAP);
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}
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EXPORT_SYMBOL(devm_ioremap);
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/**
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* devm_ioremap_uc - Managed ioremap_uc()
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* @dev: Generic device to remap IO address for
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* @offset: Resource address to map
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* @size: Size of map
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*
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* Managed ioremap_uc(). Map is automatically unmapped on driver detach.
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*/
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void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
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resource_size_t size)
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{
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return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_UC);
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}
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EXPORT_SYMBOL_GPL(devm_ioremap_uc);
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/**
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* devm_ioremap_wc - Managed ioremap_wc()
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* @dev: Generic device to remap IO address for
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* @offset: Resource address to map
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* @size: Size of map
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*
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* Managed ioremap_wc(). Map is automatically unmapped on driver detach.
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*/
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void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
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resource_size_t size)
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{
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return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_WC);
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}
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EXPORT_SYMBOL(devm_ioremap_wc);
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/**
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* devm_iounmap - Managed iounmap()
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* @dev: Generic device to unmap for
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* @addr: Address to unmap
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*
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* Managed iounmap(). @addr must have been mapped using devm_ioremap*().
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*/
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void devm_iounmap(struct device *dev, void __iomem *addr)
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{
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WARN_ON(devres_destroy(dev, devm_ioremap_release, devm_ioremap_match,
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(__force void *)addr));
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iounmap(addr);
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}
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EXPORT_SYMBOL(devm_iounmap);
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static void __iomem *
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__devm_ioremap_resource(struct device *dev, const struct resource *res,
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enum devm_ioremap_type type)
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{
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resource_size_t size;
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void __iomem *dest_ptr;
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char *pretty_name;
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BUG_ON(!dev);
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if (!res || resource_type(res) != IORESOURCE_MEM) {
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dev_err(dev, "invalid resource\n");
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return IOMEM_ERR_PTR(-EINVAL);
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}
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size = resource_size(res);
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if (res->name)
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pretty_name = devm_kasprintf(dev, GFP_KERNEL, "%s %s",
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dev_name(dev), res->name);
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else
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pretty_name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
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if (!pretty_name)
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return IOMEM_ERR_PTR(-ENOMEM);
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if (!devm_request_mem_region(dev, res->start, size, pretty_name)) {
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dev_err(dev, "can't request region for resource %pR\n", res);
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return IOMEM_ERR_PTR(-EBUSY);
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}
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dest_ptr = __devm_ioremap(dev, res->start, size, type);
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if (!dest_ptr) {
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dev_err(dev, "ioremap failed for resource %pR\n", res);
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devm_release_mem_region(dev, res->start, size);
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dest_ptr = IOMEM_ERR_PTR(-ENOMEM);
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}
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return dest_ptr;
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}
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/**
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* devm_ioremap_resource() - check, request region, and ioremap resource
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* @dev: generic device to handle the resource for
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* @res: resource to be handled
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*
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* Checks that a resource is a valid memory region, requests the memory
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* region and ioremaps it. All operations are managed and will be undone
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* on driver detach.
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*
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* Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
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* on failure. Usage example:
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*
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* res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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* base = devm_ioremap_resource(&pdev->dev, res);
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* if (IS_ERR(base))
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* return PTR_ERR(base);
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*/
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void __iomem *devm_ioremap_resource(struct device *dev,
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const struct resource *res)
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{
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return __devm_ioremap_resource(dev, res, DEVM_IOREMAP);
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}
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EXPORT_SYMBOL(devm_ioremap_resource);
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/**
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* devm_ioremap_resource_wc() - write-combined variant of
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* devm_ioremap_resource()
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* @dev: generic device to handle the resource for
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* @res: resource to be handled
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*
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* Returns a pointer to the remapped memory or an ERR_PTR() encoded error code
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* on failure. Usage example:
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*/
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void __iomem *devm_ioremap_resource_wc(struct device *dev,
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const struct resource *res)
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{
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return __devm_ioremap_resource(dev, res, DEVM_IOREMAP_WC);
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}
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/*
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* devm_of_iomap - Requests a resource and maps the memory mapped IO
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* for a given device_node managed by a given device
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*
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* Checks that a resource is a valid memory region, requests the memory
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* region and ioremaps it. All operations are managed and will be undone
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* on driver detach of the device.
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*
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* This is to be used when a device requests/maps resources described
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* by other device tree nodes (children or otherwise).
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*
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* @dev: The device "managing" the resource
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* @node: The device-tree node where the resource resides
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* @index: index of the MMIO range in the "reg" property
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* @size: Returns the size of the resource (pass NULL if not needed)
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* Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
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* error code on failure. Usage example:
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*
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* base = devm_of_iomap(&pdev->dev, node, 0, NULL);
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* if (IS_ERR(base))
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* return PTR_ERR(base);
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*
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* Please Note: This is not a one-to-one replacement for of_iomap() because the
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* of_iomap() function does not track whether the region is already mapped. If
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* two drivers try to map the same memory, the of_iomap() function will succeed
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* but the the devm_of_iomap() function will return -EBUSY.
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*
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*/
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void __iomem *devm_of_iomap(struct device *dev, struct device_node *node, int index,
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resource_size_t *size)
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{
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struct resource res;
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if (of_address_to_resource(node, index, &res))
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return IOMEM_ERR_PTR(-EINVAL);
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if (size)
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*size = resource_size(&res);
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return devm_ioremap_resource(dev, &res);
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}
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EXPORT_SYMBOL(devm_of_iomap);
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#ifdef CONFIG_HAS_IOPORT_MAP
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/*
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* Generic iomap devres
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*/
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static void devm_ioport_map_release(struct device *dev, void *res)
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{
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ioport_unmap(*(void __iomem **)res);
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}
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static int devm_ioport_map_match(struct device *dev, void *res,
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void *match_data)
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{
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return *(void **)res == match_data;
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}
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/**
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* devm_ioport_map - Managed ioport_map()
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* @dev: Generic device to map ioport for
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* @port: Port to map
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* @nr: Number of ports to map
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*
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* Managed ioport_map(). Map is automatically unmapped on driver
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* detach.
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*/
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void __iomem *devm_ioport_map(struct device *dev, unsigned long port,
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unsigned int nr)
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{
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void __iomem **ptr, *addr;
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ptr = devres_alloc(devm_ioport_map_release, sizeof(*ptr), GFP_KERNEL);
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if (!ptr)
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return NULL;
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addr = ioport_map(port, nr);
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if (addr) {
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*ptr = addr;
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devres_add(dev, ptr);
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} else
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devres_free(ptr);
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return addr;
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}
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EXPORT_SYMBOL(devm_ioport_map);
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/**
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* devm_ioport_unmap - Managed ioport_unmap()
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* @dev: Generic device to unmap for
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* @addr: Address to unmap
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*
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* Managed ioport_unmap(). @addr must have been mapped using
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* devm_ioport_map().
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*/
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void devm_ioport_unmap(struct device *dev, void __iomem *addr)
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{
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ioport_unmap(addr);
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WARN_ON(devres_destroy(dev, devm_ioport_map_release,
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devm_ioport_map_match, (__force void *)addr));
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}
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EXPORT_SYMBOL(devm_ioport_unmap);
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#endif /* CONFIG_HAS_IOPORT_MAP */
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#ifdef CONFIG_PCI
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/*
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* PCI iomap devres
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*/
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#define PCIM_IOMAP_MAX PCI_STD_NUM_BARS
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struct pcim_iomap_devres {
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void __iomem *table[PCIM_IOMAP_MAX];
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};
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static void pcim_iomap_release(struct device *gendev, void *res)
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{
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struct pci_dev *dev = to_pci_dev(gendev);
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struct pcim_iomap_devres *this = res;
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int i;
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for (i = 0; i < PCIM_IOMAP_MAX; i++)
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if (this->table[i])
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pci_iounmap(dev, this->table[i]);
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}
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/**
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* pcim_iomap_table - access iomap allocation table
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* @pdev: PCI device to access iomap table for
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*
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* Access iomap allocation table for @dev. If iomap table doesn't
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* exist and @pdev is managed, it will be allocated. All iomaps
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* recorded in the iomap table are automatically unmapped on driver
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* detach.
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*
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* This function might sleep when the table is first allocated but can
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* be safely called without context and guaranteed to succed once
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* allocated.
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*/
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void __iomem * const *pcim_iomap_table(struct pci_dev *pdev)
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{
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struct pcim_iomap_devres *dr, *new_dr;
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dr = devres_find(&pdev->dev, pcim_iomap_release, NULL, NULL);
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if (dr)
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return dr->table;
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new_dr = devres_alloc(pcim_iomap_release, sizeof(*new_dr), GFP_KERNEL);
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if (!new_dr)
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return NULL;
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dr = devres_get(&pdev->dev, new_dr, NULL, NULL);
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return dr->table;
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}
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EXPORT_SYMBOL(pcim_iomap_table);
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/**
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* pcim_iomap - Managed pcim_iomap()
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* @pdev: PCI device to iomap for
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* @bar: BAR to iomap
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* @maxlen: Maximum length of iomap
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*
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* Managed pci_iomap(). Map is automatically unmapped on driver
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* detach.
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*/
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void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen)
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{
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void __iomem **tbl;
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BUG_ON(bar >= PCIM_IOMAP_MAX);
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tbl = (void __iomem **)pcim_iomap_table(pdev);
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if (!tbl || tbl[bar]) /* duplicate mappings not allowed */
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return NULL;
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tbl[bar] = pci_iomap(pdev, bar, maxlen);
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return tbl[bar];
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}
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EXPORT_SYMBOL(pcim_iomap);
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/**
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* pcim_iounmap - Managed pci_iounmap()
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* @pdev: PCI device to iounmap for
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* @addr: Address to unmap
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*
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* Managed pci_iounmap(). @addr must have been mapped using pcim_iomap().
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*/
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void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr)
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{
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void __iomem **tbl;
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int i;
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pci_iounmap(pdev, addr);
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tbl = (void __iomem **)pcim_iomap_table(pdev);
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BUG_ON(!tbl);
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for (i = 0; i < PCIM_IOMAP_MAX; i++)
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if (tbl[i] == addr) {
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tbl[i] = NULL;
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return;
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}
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WARN_ON(1);
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}
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EXPORT_SYMBOL(pcim_iounmap);
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/**
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* pcim_iomap_regions - Request and iomap PCI BARs
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* @pdev: PCI device to map IO resources for
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* @mask: Mask of BARs to request and iomap
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* @name: Name used when requesting regions
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*
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* Request and iomap regions specified by @mask.
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*/
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int pcim_iomap_regions(struct pci_dev *pdev, int mask, const char *name)
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{
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void __iomem * const *iomap;
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int i, rc;
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iomap = pcim_iomap_table(pdev);
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if (!iomap)
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return -ENOMEM;
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for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
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unsigned long len;
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if (!(mask & (1 << i)))
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continue;
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rc = -EINVAL;
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len = pci_resource_len(pdev, i);
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if (!len)
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goto err_inval;
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rc = pci_request_region(pdev, i, name);
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if (rc)
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goto err_inval;
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rc = -ENOMEM;
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if (!pcim_iomap(pdev, i, 0))
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goto err_region;
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}
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return 0;
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err_region:
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pci_release_region(pdev, i);
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err_inval:
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while (--i >= 0) {
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if (!(mask & (1 << i)))
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continue;
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pcim_iounmap(pdev, iomap[i]);
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pci_release_region(pdev, i);
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}
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return rc;
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}
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EXPORT_SYMBOL(pcim_iomap_regions);
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/**
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* pcim_iomap_regions_request_all - Request all BARs and iomap specified ones
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* @pdev: PCI device to map IO resources for
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* @mask: Mask of BARs to iomap
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* @name: Name used when requesting regions
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*
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* Request all PCI BARs and iomap regions specified by @mask.
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*/
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int pcim_iomap_regions_request_all(struct pci_dev *pdev, int mask,
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const char *name)
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{
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int request_mask = ((1 << 6) - 1) & ~mask;
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int rc;
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rc = pci_request_selected_regions(pdev, request_mask, name);
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if (rc)
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return rc;
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rc = pcim_iomap_regions(pdev, mask, name);
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if (rc)
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pci_release_selected_regions(pdev, request_mask);
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return rc;
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}
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EXPORT_SYMBOL(pcim_iomap_regions_request_all);
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/**
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* pcim_iounmap_regions - Unmap and release PCI BARs
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* @pdev: PCI device to map IO resources for
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* @mask: Mask of BARs to unmap and release
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*
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* Unmap and release regions specified by @mask.
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*/
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void pcim_iounmap_regions(struct pci_dev *pdev, int mask)
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{
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void __iomem * const *iomap;
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int i;
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iomap = pcim_iomap_table(pdev);
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if (!iomap)
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return;
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for (i = 0; i < PCIM_IOMAP_MAX; i++) {
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if (!(mask & (1 << i)))
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continue;
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pcim_iounmap(pdev, iomap[i]);
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pci_release_region(pdev, i);
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}
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}
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EXPORT_SYMBOL(pcim_iounmap_regions);
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#endif /* CONFIG_PCI */
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