Messages in this thread | | | Subject | Re: [PATCH v4 5/6] arch: introduce memremap_cache() and memremap_wt() | From | Toshi Kani <> | Date | Fri, 19 Jun 2015 15:28:52 -0600 |
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On Thu, 2015-06-11 at 17:19 -0400, Dan Williams wrote: > 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_*(). > > The ARCH_HAS_MEMREMAP kconfig symbol is introduced for archs to assert > that it is safe to recast / reuse the return value from ioremap as a > normal pointer to memory. In other words, archs that mandate specific > accessors for __iomem are not memremap() capable and drivers that care, > like pmem, can add a dependency to disable themselves on these archs. : > +#ifdef CONFIG_ARCH_HAS_MEMREMAP > +/* > + * memremap() is "ioremap" for cases where it is known that the resource > + * being mapped does not have i/o side effects and the __iomem > + * annotation is not applicable. > + */ > +static bool memremap_valid(resource_size_t offset, size_t size) > +{ > + if (region_is_ram(offset, size) != 0) {
I noticed that region_is_ram() is buggy and always returns -1. I will submit the fix shortly.
Thanks, -Toshi
> + WARN_ONCE(1, "memremap attempted on ram %pa size: %zu\n", > + &offset, size); > + return false; > + } > + return true; > +}
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