• Will Deacon's avatar
    mmu_gather: move minimal range calculations into generic code · fb7332a9
    Will Deacon authored
    On architectures with hardware broadcasting of TLB invalidation messages
    , it makes sense to reduce the range of the mmu_gather structure when
    unmapping page ranges based on the dirty address information passed to
    tlb_remove_tlb_entry.
    
    arm64 already does this by directly manipulating the start/end fields
    of the gather structure, but this confuses the generic code which
    does not expect these fields to change and can end up calculating
    invalid, negative ranges when forcing a flush in zap_pte_range.
    
    This patch moves the minimal range calculation out of the arm64 code
    and into the generic implementation, simplifying zap_pte_range in the
    process (which no longer needs to care about start/end, since they will
    point to the appropriate ranges already). With the range being tracked
    by core code, the need_flush flag is dropped in favour of checking that
    the end of the range has actually been set.
    
    Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
    Cc: Michal Simek <monstr@monstr.eu>
    Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    fb7332a9
tlb.h 6.45 KB