From: Dan Williams Date: Tue, 11 Aug 2015 03:07:06 +0000 (-0400) Subject: arch: introduce memremap() X-Git-Tag: omap-for-v4.3/fixes-rc1~64^2~8^2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=92281dee825f6d2eb07c441437e4196a44b0861c;p=pandora-kernel.git 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_() 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_() 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 Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams --- Reading git-diff-tree failed