diff options
Diffstat (limited to 'arch/powerpc/include/asm/book3s/64/mmu.h')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/mmu.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h index 1ceee000c18d..a809bdd77322 100644 --- a/arch/powerpc/include/asm/book3s/64/mmu.h +++ b/arch/powerpc/include/asm/book3s/64/mmu.h @@ -35,6 +35,21 @@ typedef pte_t *pgtable_t; #endif /* __ASSEMBLY__ */ +/* + * If we store section details in page->flags we can't increase the MAX_PHYSMEM_BITS + * if we increase SECTIONS_WIDTH we will not store node details in page->flags and + * page_to_nid does a page->section->node lookup + * Hence only increase for VMEMMAP. Further depending on SPARSEMEM_EXTREME reduce + * memory requirements with large number of sections. + * 51 bits is the max physical real address on POWER9 + */ +#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_SPARSEMEM_EXTREME) && \ + defined(CONFIG_PPC_64K_PAGES) +#define MAX_PHYSMEM_BITS 51 +#else +#define MAX_PHYSMEM_BITS 46 +#endif + /* 64-bit classic hash table MMU */ #include <asm/book3s/64/mmu-hash.h> |