linux-toradex.git/drivers/nvdimm/region_devs.c, branch v4.14-rc3

nfit, libnvdimm, region: export 'position' in mapping info

2017-08-05T00:20:16+00:00

It is useful to be able to know the position of a DIMM in an
interleave-set. Consider the case where the order of the DIMMs changes
causing a namespace to be invalidated because the interleave-set cookie no
longer matches. If the before and after state of each DIMM position is
known this state debugged by the system owner.

Signed-off-by: Dan Williams

Merge branch 'for-4.13/dax' into libnvdimm-for-next

2017-07-03T23:54:58+00:00

acpi, nfit: quiet invalid block-aperture-region warnings

2017-06-29T20:50:38+00:00

This state is already visible by userspace since the BLK region will not
be enabled, and it is otherwise benign as it usually indicates that the
DIMM is not configured.

Signed-off-by: Dan Williams

libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region

2017-06-29T16:29:50+00:00

The pmem driver attaches to both persistent and volatile memory ranges
advertised by the ACPI NFIT. When the region is volatile it is redundant
to spend cycles flushing caches at fsync(). Check if the hosting region
is volatile and do not set dax_write_cache() if it is.

Cc: Jan Kara 
Cc: Jeff Moyer 
Cc: Christoph Hellwig 
Cc: Matthew Wilcox 
Cc: Ross Zwisler 
Signed-off-by: Dan Williams

libnvdimm, nfit: enable support for volatile ranges

2017-06-27T23:44:13+00:00

Allow volatile nfit ranges to participate in all the same infrastructure
provided for persistent memory regions. A resulting resulting namespace
device will still be called "pmem", but the parent region type will be
"nd_volatile". This is in preparation for disabling the dax ->flush()
operation in the pmem driver when it is hosted on a volatile range.

Cc: Jan Kara 
Cc: Jeff Moyer 
Cc: Christoph Hellwig 
Cc: Matthew Wilcox 
Cc: Ross Zwisler 
Signed-off-by: Dan Williams

libnvdimm, pmem: fix persistence warning

2017-06-27T23:44:01+00:00

The pmem driver assumes if platform firmware describes the memory
devices associated with a persistent memory range and
CONFIG_ARCH_HAS_PMEM_API=y that it has all the mechanism necessary to
flush data to a power-fail safe zone. We warn if the firmware does not
describe memory devices, but we also need to warn if the architecture
does not claim pmem support.

Cc: Jeff Moyer 
Cc: Christoph Hellwig 
Cc: Matthew Wilcox 
Cc: Ross Zwisler 
Reviewed-by: Jan Kara 
Signed-off-by: Dan Williams

x86, libnvdimm, pmem: remove global pmem api

2017-06-27T23:29:54+00:00

Now that all callers of the pmem api have been converted to dax helpers that
call back to the pmem driver, we can remove include/linux/pmem.h and
asm/pmem.h.

Cc: 
Cc: Jeff Moyer 
Cc: Ingo Molnar 
Cc: Christoph Hellwig 
Cc: Toshi Kani 
Cc: Oliver O'Halloran 
Cc: Ross Zwisler 
Reviewed-by: Jan Kara 
Signed-off-by: Dan Williams

libnvdimm, label: add v1.2 interleave-set-cookie algorithm

2017-06-15T21:31:39+00:00

The interleave-set-cookie algorithm is extended to incorporate all the
same components that are used to generate an nvdimm unique-id. For
backwards compatibility we still maintain the old v1.1 definition.

Reported-by: Nicholas Moulin 
Reported-by: Kaushik Kanetkar 
Signed-off-by: Dan Williams

x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations

2017-06-09T16:09:56+00:00

The pmem driver has a need to transfer data with a persistent memory
destination and be able to rely on the fact that the destination writes are not
cached. It is sufficient for the writes to be flushed to a cpu-store-buffer
(non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync()
to ensure data-writes have reached a power-fail-safe zone in the platform. The
fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn
around and fence previous writes with an "sfence".

Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and
memcpy_flushcache, that guarantee that the destination buffer is not dirty in
the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines
will be used to replace the "pmem api" (include/linux/pmem.h +
arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache()
and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
config symbol, and fallback to copy_from_iter_nocache() and plain memcpy()
otherwise.

This is meant to satisfy the concern from Linus that if a driver wants to do
something beyond the normal nocache semantics it should be something private to
that driver [1], and Al's concern that anything uaccess related belongs with
the rest of the uaccess code [2].

The first consumer of this interface is a new 'copy_from_iter' dax operation so
that pmem can inject cache maintenance operations without imposing this
overhead on other dax-capable drivers.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html

Cc: 
Cc: Jan Kara 
Cc: Jeff Moyer 
Cc: Ingo Molnar 
Cc: Christoph Hellwig 
Cc: Toshi Kani 
Cc: "H. Peter Anvin" 
Cc: Al Viro 
Cc: Thomas Gleixner 
Cc: Matthew Wilcox 
Reviewed-by: Ross Zwisler 
Signed-off-by: Dan Williams

libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED

2017-05-04T21:01:24+00:00

This is a preparation patch for handling locked nvdimm label regions, a
new concept as introduced by the latest DSM document on pmem.io [1]. A
future patch will leverage nvdimm_set_locked() at DIMM probe time to
flag regions that can not be enabled. There should be no functional
difference resulting from this change.

[1]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example-V1.3.pdf

Signed-off-by: Dan Williams