On Thu, Jul 30, 2015 at 12:54:07PM -0400, Dan Williams wrote: > diff --git a/include/linux/io.h b/include/linux/io.h > index fb5a99800e77..3fcf6256c088 100644 > --- a/include/linux/io.h > +++ b/include/linux/io.h > @@ -121,4 +121,13 @@ static inline int arch_phys_wc_index(int handle) > #endif > #endif > > +enum { > + /* See memremap() kernel-doc for usage description... */ > + MEMREMAP_WB = 1 << 0, > + MEMREMAP_WT = 1 << 1, > +}; Same feedback for enum nameing and also kdoc style. > diff --git a/kernel/memremap.c b/kernel/memremap.c > new file mode 100644 > index 000000000000..27637f42f30d > --- /dev/null > +++ b/kernel/memremap.c <-- ... --> > +/** > + * memremap() - remap an iomem_resource as cacheable memory > + * @offset: iomem resource start address > + * @size: size of remap > + * @flags: either MEMREMAP_WB or MEMREMAP_WT > + * > + * 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. > + * > + * MEMREMAP_WB - matches the default mapping for "System RAM" on > + * the architecture. This is usually a read-allocate write-back cache. > + * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM > + * memremap() will bypass establishing a new mapping and instead return > + * a pointer into the direct map. > + * > + * MEMREMAP_WT - establish a mapping whereby writes either bypass the > + * cache or are written through to memory and never exist in a > + * cache-dirty state with respect to program visibility. Attempts to > + * map "System RAM" with this mapping type will fail. Then you can extrend all this on kdoc on the enum. > + */ > +void *memremap(resource_size_t offset, size_t size, unsigned long flags) > +{ > + int is_ram = region_intersects(offset, size, "System RAM"); This could be the enum region_intersect_type, then if the region enum is extended you'd get a compiler error if one type was not handled. Luis -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html