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authorDan Williams <dan.j.williams@intel.com>2015-08-10 23:07:06 -0400
committerDan Williams <dan.j.williams@intel.com>2015-08-14 13:23:28 -0400
commit92281dee825f6d2eb07c441437e4196a44b0861c (patch)
tree2d8e24a39dfacf286ab66644545af853056d64f7 /arch
parent92b19ff50e8f242392d78b2aacc5b5b672f1796b (diff)
arch: introduce memremap()
Existing users of ioremap_cache() are mapping memory that is known in advance to not have i/o side effects. These users are forced to cast away the __iomem annotation, or otherwise neglect to fix the sparse errors thrown when dereferencing pointers to this memory. Provide memremap() as a non __iomem annotated ioremap_*() in the case when ioremap is otherwise a pointer to cacheable memory. Empirically, ioremap_<cacheable-type>() call sites are seeking memory-like semantics (e.g. speculative reads, and prefetching permitted). memremap() is a break from the ioremap implementation pattern of adding a new memremap_<type>() for each mapping type and having silent compatibility fall backs. Instead, the implementation defines flags that are passed to the central memremap() and if a mapping type is not supported by an arch memremap returns NULL. We introduce a memremap prototype as a trivial wrapper of ioremap_cache() and ioremap_wt(). Later, once all ioremap_cache() and ioremap_wt() usage has been removed from drivers we teach archs to implement arch_memremap() with the ability to strictly enforce the mapping type. Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/ia64/include/asm/io.h1
-rw-r--r--arch/sh/include/asm/io.h1
-rw-r--r--arch/xtensa/include/asm/io.h1
3 files changed, 3 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h
index 80a7e34be009..9041bbe2b7b4 100644
--- a/arch/ia64/include/asm/io.h
+++ b/arch/ia64/include/asm/io.h
@@ -435,6 +435,7 @@ static inline void __iomem * ioremap_cache (unsigned long phys_addr, unsigned lo
{
return ioremap(phys_addr, size);
}
+#define ioremap_cache ioremap_cache
/*
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index 728c4c571f40..6194e20fccca 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -342,6 +342,7 @@ ioremap_cache(phys_addr_t offset, unsigned long size)
{
return __ioremap_mode(offset, size, PAGE_KERNEL);
}
+#define ioremap_cache ioremap_cache
#ifdef CONFIG_HAVE_IOREMAP_PROT
static inline void __iomem *
diff --git a/arch/xtensa/include/asm/io.h b/arch/xtensa/include/asm/io.h
index c39bb6e61911..867840f5400f 100644
--- a/arch/xtensa/include/asm/io.h
+++ b/arch/xtensa/include/asm/io.h
@@ -57,6 +57,7 @@ static inline void __iomem *ioremap_cache(unsigned long offset,
else
BUG();
}
+#define ioremap_cache ioremap_cache
#define ioremap_wc ioremap_nocache
#define ioremap_wt ioremap_nocache