• David S. Miller's avatar
    sparc64: Move to 64-bit PGDs and PMDs. · 2b77933c
    David S. Miller authored
    To make the page tables compact, we were using 32-bit PGDs and PMDs.
    We only had to support <= 43 bits of physical addresses so this was
    quite feasible.
    
    In order to support larger physical addresses we have to move to
    64-bit PGDs and PMDs.
    
    Most of the changes are straight-forward:
    
    1) {pgd,pmd}_t --> unsigned long
    
    2) Anything that tries to use plain "unsigned int" types with pgd/pmd
       values needs to be adjusted.  In particular things like "0U" become
       "0UL".
    
    3) {PGDIR,PMD}_BITS decrease by one.
    
    4) In the assembler page table walkers, use "ldxa" instead of "lduwa"
       and adjust the low bit masks to clear out the low 3 bits instead of
       just the low 2 bits during pgd/pmd address formation.
    
    Also, use PTRS_PER_PGD and PTRS_PER_PMD in the sizing of the
    swapper_{pg_dir,low_pmd_dir} arrays.
    
    This patch does not try to take advantage of having 64-bits in the
    PMDs to simplify the hugepage code, that will come in a subsequent
    change.
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    2b77933c
page_64.h 4.63 KB