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  • Robin Murphy's avatar
    libnvdimm, nd_blk: remove mmio_flush_range() · 5deb67f7
    Robin Murphy authored
    mmio_flush_range() suffers from a lack of clearly-defined semantics,
    and is somewhat ambiguous to port to other architectures where the
    scope of the writeback implied by "flush" and ordering might matter,
    but MMIO would tend to imply non-cacheable anyway. Per the rationale
    in 67a3e8fe
    
     ("nd_blk: change aperture mapping from WC to WB"), the
    only existing use is actually to invalidate clean cache lines for
    ARCH_MEMREMAP_PMEM type mappings *without* writeback. Since the recent
    cleanup of the pmem API, that also now happens to be the exact purpose
    of arch_invalidate_pmem(), which would be a far more well-defined tool
    for the job.
    
    Rather than risk potentially inconsistent implementations of
    mmio_flush_range() for the sake of one callsite, streamline things by
    removing it entirely and instead move the ARCH_MEMREMAP_PMEM related
    definitions up to the libnvdimm level, so they can be shared by NFIT
    as well. This allows NFIT to be enabled for arm64.
    
    Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
    Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
    5deb67f7