lib/iomap_copy.c: add __ioread32_copy()
Some drivers need to read data out of iomem areas 32-bits at a time. Add an API to do this. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com> Cc: <zajec5@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Hauke Mehrtens <hauke@hauke-m.de> Cc: Paul Walmsley <paul@pwsan.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -29,6 +29,7 @@ struct device;
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struct resource;
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__visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
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void __ioread32_copy(void *to, const void __iomem *from, size_t count);
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void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
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#ifdef CONFIG_MMU
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@ -41,6 +41,27 @@ void __attribute__((weak)) __iowrite32_copy(void __iomem *to,
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}
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EXPORT_SYMBOL_GPL(__iowrite32_copy);
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/**
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* __ioread32_copy - copy data from MMIO space, in 32-bit units
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* @to: destination (must be 32-bit aligned)
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* @from: source, in MMIO space (must be 32-bit aligned)
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* @count: number of 32-bit quantities to copy
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*
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* Copy data from MMIO space to kernel space, in units of 32 bits at a
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* time. Order of access is not guaranteed, nor is a memory barrier
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* performed afterwards.
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*/
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void __ioread32_copy(void *to, const void __iomem *from, size_t count)
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{
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u32 *dst = to;
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const u32 __iomem *src = from;
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const u32 __iomem *end = src + count;
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while (src < end)
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*dst++ = __raw_readl(src++);
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}
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EXPORT_SYMBOL_GPL(__ioread32_copy);
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/**
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* __iowrite64_copy - copy data to MMIO space, in 64-bit or 32-bit units
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* @to: destination, in MMIO space (must be 64-bit aligned)
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