On Tue, Apr 28, 2015 at 2:10 PM, Andy Lutomirski <l...@amacapital.net> wrote: > On Tue, Apr 28, 2015 at 11:26 AM, Dan Williams <dan.j.willi...@intel.com> > wrote: >> From: Ross Zwisler <ross.zwis...@linux.intel.com> >> >> The libnd implementation handles allocating dimm address space (DPA) >> between PMEM and BLK mode interfaces. After DPA has been allocated from >> a BLK-region to a BLK-namespace the nd_blk driver attaches to handle I/O >> as a struct bio based block device. Unlike PMEM, BLK is required to >> handle platform specific details like mmio register formats and memory >> controller interleave. For this reason the libnd generic nd_blk driver >> calls back into the bus provider to carry out the I/O. >> >> This initial implementation handles the BLK interface defined by the >> ACPI 6 NFIT [1] and the NVDIMM DSM Interface Example [2] composed from >> DCR (dimm control region), BDW (block data window), IDT (interleave >> descriptor) NFIT structures and the hardware register format. >> [1]: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf >> [2]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf >> >> Cc: Andy Lutomirski <l...@amacapital.net> >> Cc: Boaz Harrosh <b...@plexistor.com> >> Cc: H. Peter Anvin <h...@zytor.com> >> Cc: Jens Axboe <ax...@fb.com> >> Cc: Ingo Molnar <mi...@kernel.org> >> Cc: Christoph Hellwig <h...@lst.de> >> Signed-off-by: Ross Zwisler <ross.zwis...@linux.intel.com> >> Signed-off-by: Dan Williams <dan.j.willi...@intel.com> >> --- >> drivers/block/nd/Kconfig | 12 + >> drivers/block/nd/Makefile | 3 >> drivers/block/nd/acpi.c | 422 >> +++++++++++++++++++++++++++++++++++-- >> drivers/block/nd/acpi_nfit.h | 47 ++++ >> drivers/block/nd/blk.c | 264 +++++++++++++++++++++++ >> drivers/block/nd/libnd.h | 11 + >> drivers/block/nd/namespace_devs.c | 47 ++++ >> drivers/block/nd/nd-private.h | 3 >> drivers/block/nd/nd.h | 16 + >> drivers/block/nd/region.c | 8 + >> drivers/block/nd/region_devs.c | 65 +++++- >> drivers/block/nd/test/nfit.c | 29 +++ >> drivers/block/nd/test/nfit_test.h | 2 >> 13 files changed, 891 insertions(+), 38 deletions(-) >> create mode 100644 drivers/block/nd/blk.c >> >> diff --git a/drivers/block/nd/Kconfig b/drivers/block/nd/Kconfig >> index 612bf2b14283..bac4290129fc 100644 >> --- a/drivers/block/nd/Kconfig >> +++ b/drivers/block/nd/Kconfig >> @@ -95,6 +95,18 @@ config BLK_DEV_PMEM >> >> Say Y if you want to use a NVDIMM described by ACPI, E820, etc... >> >> +config ND_BLK >> + tristate "BLK: Block data window (aperture) device support" >> + depends on LIBND >> + default ND_ACPI >> + help >> + This driver performs I/O using a set of mmio windows on a >> + dimm. The set of apertures will all access the one DIMM. >> + Multiple windows allow multiple threads to have a different >> + portions of the dimm open at one time. >> + >> + Say Y if you want to use a NVDIMM with BLK-mode capability >> + > > This describes how it works, not what it is. How about: > > This driver exposes NVDIMM BLK regions as block devices. BLK regions > are regions of NVDIMM storage that are sector-addressable, not > byte-addressible, and do not support DAX.
They *are* byte-addressable albeit through an indirection window. The indirection windows are too small for DAX to be a viable access mode. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
