[PATCH 1/3] lib: iomap_copy: Add __ioread32_copy()
From: Stephen Boyd <hidden>
Date: 2015-09-15 19:41:35
Also in:
linux-arm-msm, lkml
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Some drivers need to read data out of iomem areas 32-bits at a time. Add an API to do this. Cc: Bjorn Andersson <redacted> Signed-off-by: Stephen Boyd <redacted> --- include/linux/io.h | 1 + lib/iomap_copy.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+)
diff --git a/include/linux/io.h b/include/linux/io.h
index de64c1e53612..72c35e0a41d1 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h@@ -29,6 +29,7 @@ struct device; struct resource; __visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count); +void __ioread32_copy(void *to, const void __iomem *from, size_t count); void __iowrite64_copy(void __iomem *to, const void *from, size_t count); #ifdef CONFIG_MMU
diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c
index 4527e751b5e0..f174d4759ef3 100644
--- a/lib/iomap_copy.c
+++ b/lib/iomap_copy.c@@ -42,6 +42,29 @@ void __attribute__((weak)) __iowrite32_copy(void __iomem *to, EXPORT_SYMBOL_GPL(__iowrite32_copy); /** + * __ioread32_copy - copy data from MMIO space, in 32-bit units + * @to: destination (must be 32-bit aligned) + * @from: source, in MMIO space (must be 32-bit aligned) + * @count: number of 32-bit quantities to copy + * + * Copy data from MMIO space to kernel space, in units of 32 bits at a + * time. Order of access is not guaranteed, nor is a memory barrier + * performed afterwards. + */ +void __attribute__((weak)) __ioread32_copy(void *to, + const void __iomem *from, + size_t count) +{ + u32 *dst = to; + const u32 __iomem *src = from; + const u32 __iomem *end = src + count; + + while (src < end) + *dst++ = __raw_readl(src++); +} +EXPORT_SYMBOL_GPL(__ioread32_copy); + +/** * __iowrite64_copy - copy data to MMIO space, in 64-bit or 32-bit units * @to: destination, in MMIO space (must be 64-bit aligned) * @from: source (must be 64-bit aligned)
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