49 lines
1.3 KiB
C
49 lines
1.3 KiB
C
/*
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* Implement the default iomap interfaces
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*
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* (C) Copyright 2004 Linus Torvalds
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*/
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#include <linux/pci.h>
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#include <linux/io.h>
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#include <linux/export.h>
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#ifdef CONFIG_PCI
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/**
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* pci_iomap - create a virtual mapping cookie for a PCI BAR
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* @dev: PCI device that owns the BAR
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* @bar: BAR number
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* @maxlen: length of the memory to map
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*
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* Using this function you will get a __iomem address to your device BAR.
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* You can access it using ioread*() and iowrite*(). These functions hide
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* the details if this is a MMIO or PIO address space and will just do what
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* you expect from them in the correct way.
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*
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* @maxlen specifies the maximum length to map. If you want to get access to
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* the complete BAR without checking for its length first, pass %0 here.
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* */
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void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
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{
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resource_size_t start = pci_resource_start(dev, bar);
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resource_size_t len = pci_resource_len(dev, bar);
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unsigned long flags = pci_resource_flags(dev, bar);
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if (!len || !start)
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return NULL;
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if (maxlen && len > maxlen)
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len = maxlen;
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if (flags & IORESOURCE_IO)
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return ioport_map(start, len);
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if (flags & IORESOURCE_MEM) {
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if (flags & IORESOURCE_CACHEABLE)
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return ioremap(start, len);
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return ioremap_nocache(start, len);
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}
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/* What? */
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return NULL;
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}
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EXPORT_SYMBOL(pci_iomap);
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#endif /* CONFIG_PCI */
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