linux-toradex.git/tools/testing/nvdimm, branch v4.4.93

tools/testing/nvdimm: fix SIGTERM vs hotplug crash

2016-09-07T06:32:36+00:00

commit d8d378fa1a0c98ecb50ca52c9bf3bc14e25aa2d2 upstream.

The unit tests crash when hotplug races the previous probe. This race
requires that the loading of the nfit_test module be terminated with
SIGTERM, and the module to be unloaded while the ars scan is still
running.

In contrast to the normal nfit driver, the unit test calls
acpi_nfit_init() twice to simulate hotplug, whereas the nominal case
goes through the acpi_nfit_notify() event handler.  The
acpi_nfit_notify() path is careful to flush the previous region
registration before servicing the hotplug event. The unit test was
missing this guarantee.

 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [] pwq_activate_delayed_work+0x47/0x170
 [..]
 Call Trace:
  [] pwq_dec_nr_in_flight+0x66/0xa0
  [] process_one_work+0x2d0/0x680
  [] ? process_one_work+0x171/0x680
  [] worker_thread+0x4e/0x480
  [] ? process_one_work+0x680/0x680
  [] ? process_one_work+0x680/0x680
  [] kthread+0xf3/0x110
  [] ret_from_fork+0x1f/0x40
  [] ? kthread_create_on_node+0x230/0x230

Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

nfit: Adjust for different _FIT and NFIT headers

2015-11-30T22:51:46+00:00

When support for _FIT was added, the code presumed that the data
returned by the _FIT method is identical to the NFIT table, which
starts with an acpi_table_header.  However, the _FIT is defined
to return a data in the format of a series of NFIT type structure
entries and as a method, has an acpi_object header rather tahn
an acpi_table_header.

To address the differences, explicitly save the acpi_table_header
from the NFIT, since it is accessible through /sys, and change
the nfit pointer in the acpi_desc structure to point to the
table entries rather than the headers.

Reported-by: Jeff Moyer (jmoyer@redhat.com>
Signed-off-by: Linda Knippers 
Acked-by: Vishal Verma 
[vishal: fix up unit test for new header assumptions]
Signed-off-by: Dan Williams

tools/testing/nvdimm, acpica: fix flag rename build breakage

2015-11-12T17:21:18+00:00

Commit ca321d1ca672 "ACPICA: Update NFIT table to rename a flags field"
performed a tree-wide s/ACPI_NFIT_MEM_ARMED/ACPI_NFIT_MEM_NOT_ARMED/
operation, but missed the tools/testing/nvdimm/ directory.

Cc: Bob Moore 
Cc: Lv Zheng 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Dan Williams

acpi: nfit: Add support for hot-add

2015-11-02T20:28:07+00:00

Add a .notify callback to the acpi_nfit_driver that gets called on a
hotplug event. From this, evaluate the _FIT ACPI method which returns
the updated NFIT with handles for the hot-plugged NVDIMM.

Iterate over the new NFIT, and add any new tables found, and
register/enable the corresponding regions.

In the nfit test framework, after normal initialization, update the NFIT
with a new hot-plugged NVDIMM, and directly call into the driver to
update its view of the available regions.

Cc: Dan Williams 
Cc: Rafael J. Wysocki 
Cc: Toshi Kani 
Cc: Elliott, Robert 
Cc: Jeff Moyer 
Cc: 
Cc: 
Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams

libnvdimm, pmem: 'struct page' for pmem

2015-08-29T03:40:04+00:00

Enable the pmem driver to handle PFN device instances.  Attaching a pmem
namespace to a pfn device triggers the driver to allocate and initialize
struct page entries for pmem.  Memory capacity for this allocation comes
exclusively from RAM for now which is suitable for low PMEM to RAM
ratios.  This mechanism will be expanded later for setting an "allocate
from PMEM" policy.

Cc: Boaz Harrosh 
Cc: Ross Zwisler 
Cc: Christoph Hellwig 
Signed-off-by: Dan Williams

libnvdimm, pfn: 'struct page' provider infrastructure

2015-08-29T03:39:36+00:00

Implement the base infrastructure for libnvdimm PFN devices. Similar to
BTT devices they take a namespace as a backing device and layer
functionality on top. In this case the functionality is reserving space
for an array of 'struct page' entries to be handed out through
pfn_to_page(). For now this is just the basic libnvdimm-device-model for
configuring the base PFN device.

As the namespace claiming mechanism for PFN devices is mostly identical
to BTT devices drivers/nvdimm/claim.c is created to house the common
bits.

Cc: Ross Zwisler 
Signed-off-by: Dan Williams

Merge branch 'pmem-api' into libnvdimm-for-next

2015-08-27T23:40:26+00:00

nd_blk: change aperture mapping from WC to WB

2015-08-27T23:38:28+00:00

This should result in a pretty sizeable performance gain for reads.  For
rough comparison I did some simple read testing using PMEM to compare
reads of write combining (WC) mappings vs write-back (WB).  This was
done on a random lab machine.

PMEM reads from a write combining mapping:
	# dd of=/dev/null if=/dev/pmem0 bs=4096 count=100000
	100000+0 records in
	100000+0 records out
	409600000 bytes (410 MB) copied, 9.2855 s, 44.1 MB/s

PMEM reads from a write-back mapping:
	# dd of=/dev/null if=/dev/pmem0 bs=4096 count=1000000
	1000000+0 records in
	1000000+0 records out
	4096000000 bytes (4.1 GB) copied, 3.44034 s, 1.2 GB/s

To be able to safely support a write-back aperture I needed to add
support for the "read flush" _DSM flag, as outlined in the DSM spec:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

This flag tells the ND BLK driver that it needs to flush the cache lines
associated with the aperture after the aperture is moved but before any
new data is read.  This ensures that any stale cache lines from the
previous contents of the aperture will be discarded from the processor
cache, and the new data will be read properly from the DIMM.  We know
that the cache lines are clean and will be discarded without any
writeback because either a) the previous aperture operation was a read,
and we never modified the contents of the aperture, or b) the previous
aperture operation was a write and we must have written back the dirtied
contents of the aperture to the DIMM before the I/O was completed.

In order to add support for the "read flush" flag I needed to add a
generic routine to invalidate cache lines, mmio_flush_range().  This is
protected by the ARCH_HAS_MMIO_FLUSH Kconfig variable, and is currently
only supported on x86.

Signed-off-by: Ross Zwisler 
Signed-off-by: Dan Williams

libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option

2015-08-19T04:34:34+00:00

We currently register a platform device for e820 type-12 memory and
register a nvdimm bus beneath it.  Registering the platform device
triggers the device-core machinery to probe for a driver, but that
search currently comes up empty.  Building the nvdimm-bus registration
into the e820_pmem platform device registration in this way forces
libnvdimm to be built-in.  Instead, convert the built-in portion of
CONFIG_X86_PMEM_LEGACY to simply register a platform device and move the
rest of the logic to the driver for e820_pmem, for the following
reasons:

1/ Letting e820_pmem support be a module allows building and testing
   libnvdimm.ko changes without rebooting

2/ All the normal policy around modules can be applied to e820_pmem
   (unbind to disable and/or blacklisting the module from loading by
   default)

3/ Moving the driver to a generic location and converting it to scan
   "iomem_resource" rather than "e820.map" means any other architecture can
   take advantage of this simple nvdimm resource discovery mechanism by
   registering a resource named "Persistent Memory (legacy)"

Cc: Christoph Hellwig 
Signed-off-by: Dan Williams

pmem: switch to devm_ allocations

2015-08-14T20:01:21+00:00

Signed-off-by: Christoph Hellwig 
[djbw: tools/testing/nvdimm/ and memunmap_pmem support]
Reviewed-by: Ross Zwisler 
Signed-off-by: Dan Williams