On Tue, Jan 11, 2022 at 12:31:58PM +0200, Mike Rapoport wrote: > > --- a/include/linux/memblock.h > > +++ b/include/linux/memblock.h > > @@ -481,6 +481,8 @@ phys_addr_t memblock_reserved_size(void); > > phys_addr_t memblock_start_of_DRAM(void); > > phys_addr_t memblock_end_of_DRAM(void); > > void memblock_enforce_memory_limit(phys_addr_t memory_limit); > > +void memblock_set_usable_range(phys_addr_t base, phys_addr_t size); > > +void memblock_enforce_usable_range(void); > > void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size); > > void memblock_mem_limit_remove_map(phys_addr_t limit); > > We already have 3 very similar interfaces that deal with memory capping. > Now you suggest to add fourth that will "generically" solve a single use > case of DT, EFI and kdump interaction on arm64. > > Looks like a workaround for a fundamental issue of incompatibility between > DT and EFI wrt memory registration. Yep, I figured this would be the main argument against this - arm64 already added several other more-or-less special cased interfaces over time. I'm more than happy to solve this in a different way. What would you suggest: 1) Try to merge the similar interfaces in to one. 2) Just deal with it at a lower (arm64) level? 3) Some other way? Thanks, - Frank