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author | Dan Williams <dan.j.williams@intel.com> | 2015-08-10 23:07:06 -0400 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2015-08-14 13:23:28 -0400 |
commit | 92281dee825f6d2eb07c441437e4196a44b0861c (patch) | |
tree | 2d8e24a39dfacf286ab66644545af853056d64f7 /.mailmap | |
parent | 92b19ff50e8f242392d78b2aacc5b5b672f1796b (diff) | |
download | linux-rt-92281dee825f6d2eb07c441437e4196a44b0861c.tar.gz |
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 '.mailmap')
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