diff options
| -rw-r--r-- | arch/mips/include/asm/io.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h index a363d5fa281f..01e1f62d9d12 100644 --- a/arch/mips/include/asm/io.h +++ b/arch/mips/include/asm/io.h @@ -12,6 +12,8 @@ #ifndef _ASM_IO_H #define _ASM_IO_H +#define ARCH_HAS_IOREMAP_WC + #include <linux/compiler.h> #include <linux/kernel.h> #include <linux/types.h> @@ -278,6 +280,27 @@ static inline void __iomem * __ioremap_mode(phys_addr_t offset, unsigned long si #define ioremap_cache ioremap_cachable /* + * ioremap_wc - map bus memory into CPU space + * @offset: bus address of the memory + * @size: size of the resource to map + * + * ioremap_wc performs a platform specific sequence of operations to + * make bus memory CPU accessible via the readb/readw/readl/writeb/ + * writew/writel functions and the other mmio helpers. The returned + * address is not guaranteed to be usable directly as a virtual + * address. + * + * This version of ioremap ensures that the memory is marked uncachable + * but accelerated by means of write-combining feature. It is specifically + * useful for PCIe prefetchable windows, which may vastly improve a + * communications performance. If it was determined on boot stage, what + * CPU CCA doesn't support UCA, the method shall fall-back to the + * _CACHE_UNCACHED option (see cpu_probe() method). + */ +#define ioremap_wc(offset, size) \ + __ioremap_mode((offset), (size), boot_cpu_data.writecombine) + +/* * These two are MIPS specific ioremap variant. ioremap_cacheable_cow * requests a cachable mapping, ioremap_uncached_accelerated requests a * mapping using the uncached accelerated mode which isn't supported on |