92b19ff50e
Quoting Arnd:
I was thinking the opposite approach and basically removing all uses
of IORESOURCE_CACHEABLE from the kernel. There are only a handful of
them.and we can probably replace them all with hardcoded
ioremap_cached() calls in the cases they are actually useful.
All existing usages of IORESOURCE_CACHEABLE call ioremap() instead of
ioremap_nocache() if the resource is cacheable, however ioremap() is
uncached by default. Clearly none of the existing usages care about the
cacheability. Particularly devm_ioremap_resource() never worked as
advertised since it always fell back to plain ioremap().
Clean this up as the new direction we want is to convert
ioremap_<type>() usages to memremap(..., flags).
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
71 lines
2.1 KiB
C
71 lines
2.1 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_range - 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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* @offset: map memory at the given offset in BAR
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* @maxlen: max 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 from offset to the end, pass %0 here.
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* */
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void __iomem *pci_iomap_range(struct pci_dev *dev,
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int bar,
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unsigned long offset,
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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 <= offset || !start)
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return NULL;
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len -= offset;
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start += offset;
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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 __pci_ioport_map(dev, start, len);
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if (flags & IORESOURCE_MEM)
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return ioremap(start, len);
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/* What? */
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return NULL;
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}
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EXPORT_SYMBOL(pci_iomap_range);
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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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return pci_iomap_range(dev, bar, 0, maxlen);
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}
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EXPORT_SYMBOL(pci_iomap);
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#endif /* CONFIG_PCI */
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