On Thu, Jun 18, 2020 at 06:45:28AM +0530, Anshuman Khandual wrote: > vmemmap_populate_basepages() is used across platforms to allocate backing > memory for vmemmap mapping. This is used as a standard default choice or > as a fallback when intended huge pages allocation fails. This just creates > entire vmemmap mapping with base pages (PAGE_SIZE). > > On arm64 platforms, vmemmap_populate_basepages() is called instead of the > platform specific vmemmap_populate() when ARM64_SWAPPER_USES_SECTION_MAPS > is not enabled as in case for ARM64_16K_PAGES and ARM64_64K_PAGES configs. > > At present vmemmap_populate_basepages() does not support allocating from > driver defined struct vmem_altmap while trying to create vmemmap mapping > for a device memory range. It prevents ARM64_16K_PAGES and ARM64_64K_PAGES > configs on arm64 from supporting device memory with vmemap_altmap request. > > This enables vmem_altmap support in vmemmap_populate_basepages() unlocking > device memory allocation for vmemap mapping on arm64 platforms with 16K or > 64K base page configs. > > Each architecture should evaluate and decide on subscribing device memory > based base page allocation through vmemmap_populate_basepages(). Hence lets > keep it disabled on all archs in order to preserve the existing semantics. > A subsequent patch enables it on arm64. > > Cc: Catalin Marinas <[email protected]> > Cc: Will Deacon <[email protected]> > Cc: Mark Rutland <[email protected]> > Cc: Paul Walmsley <[email protected]> > Cc: Palmer Dabbelt <[email protected]> > Cc: Tony Luck <[email protected]> > Cc: Fenghua Yu <[email protected]> > Cc: Dave Hansen <[email protected]> > Cc: Andy Lutomirski <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: David Hildenbrand <[email protected]> > Cc: Mike Rapoport <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: "Matthew Wilcox (Oracle)" <[email protected]> > Cc: "Kirill A. Shutemov" <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Dan Williams <[email protected]> > Cc: Pavel Tatashin <[email protected]> > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Cc: [email protected] > Tested-by: Jia He <[email protected]> > Acked-by: Will Deacon <[email protected]> > Signed-off-by: Anshuman Khandual <[email protected]>
For arm64: Acked-by: Catalin Marinas <[email protected]>
