Messages in this thread | | | Subject | Re: [Patch V6 12/16] mm: provide early_memremap_ro to establish read-only mapping | From | Vlastimil Babka <> | Date | Thu, 6 Aug 2015 15:08:33 +0200 |
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On 08/06/2015 03:02 PM, Juergen Gross wrote: > On 08/06/2015 02:46 PM, Vlastimil Babka wrote: >> On 07/17/2015 06:51 AM, Juergen Gross wrote: >> >> ... and here for !CONFIG_MMU. >> >> So, what about CONFIG_MMU && !FIXMAP_PAGE_RO combinations? Which >> translates to CONFIG_MMU && !PAGE_KERNEL_RO. Maybe they don't exist, but >> then it's still awkward to see the combination in the code left >> unimplemented. > > At least there are some architectures without #define PAGE_KERNEL_RO but > testing CONFIG_MMU (arm, m68k, xtensa). > >> Would it be perhaps simpler to assume the same thing as in >> drivers/base/firmware_class.c ? >> >> /* Some architectures don't have PAGE_KERNEL_RO */ >> #ifndef PAGE_KERNEL_RO >> #define PAGE_KERNEL_RO PAGE_KERNEL >> #endif >> >> Or would it be dangerous here to silently lose the read-only protection? > > The only reason to use this function instead of early_memremap() is the > mandatory read-only mapping. My intention was to let the build fail in > case it is being used but not implemented. An architecture requiring the > function but having no PAGE_KERNEL_RO still can define FIXMAP_PAGE_RO.
OK, in that case
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Juergen >
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