Patch 5 adds support for the "read flush" _DSM flag, allowing us to change the ND BLK aperture mapping from write-combining to write-back via memremap_pmem(). Patch 6 updates the DAX I/O path so that all operations that store data (I/O writes, zeroing blocks, punching holes, etc.) properly synchronize the stores to media using the PMEM API. This ensures that the data DAX is writing is durable on media before the operation completes. Patches 1-4 are cleanup patches and additions to the PMEM API that make patches 5 and 6 possible. Regarding the choice to add both flush_cache_pmem() and wb_cache_pmem() to the PMEM API, I had initially implemented flush_cache_pmem() as a generic function flush_io_cache_range() in the spirit of flush_cache_range(), etc., in cacheflush.h. I eventually moved it into the PMEM API because a) it has a common and consistent use of the __pmem annotation, b) it has a clear fallback method for architectures that don't support it, as opposed to APIs in cacheflush.h which would need to be added individually to all other architectures. It can be argued that the flush API could apply to other uses beyond PMEM such as flushing cache lines associated with other types of sliding MMIO windows. At this point I'm inclined to have it as part of the PMEM API, and then take on the effort of making it a general cache flusing API if other users come along. Ross Zwisler (6): pmem: remove indirection layer arch_has_pmem_api() x86: clean up conditional pmem includes x86: add clwb_cache_range() pmem: Add wb_cache_pmem() and flush_cache_pmem() nd_blk: add support for "read flush" DSM flag dax: update I/O path to do proper PMEM flushing arch/x86/include/asm/cacheflush.h | 24 +++++++++-------- arch/x86/mm/pageattr.c | 23 ++++++++++++++++ drivers/acpi/nfit.c | 18 ++++++------- drivers/acpi/nfit.h | 6 ++++- fs/dax.c | 55 +++++++++++++++++++++++++++++++-------- include/linux/pmem.h | 36 ++++++++++++++++++------- 6 files changed, 120 insertions(+), 42 deletions(-) -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
