A bugfix just tried to address a randconfig build problem and introduced
a variant of the same problem: with CONFIG_LIBNVDIMM=y and
CONFIG_NVDIMM_DAX=m, the nvdimm module now fails to link:

drivers/nvdimm/built-in.o: In function `to_nd_device_type':
bus.c:(.text+0x1b5d): undefined reference to `is_nd_dax'
drivers/nvdimm/built-in.o: In function `nd_region_notify_driver_action.constprop.2':
region_devs.c:(.text+0x6b6c): undefined reference to `is_nd_dax'
region_devs.c:(.text+0x6b8c): undefined reference to `to_nd_dax'
drivers/nvdimm/built-in.o: In function `nd_region_probe':
region.c:(.text+0x70f3): undefined reference to `nd_dax_create'
drivers/nvdimm/built-in.o: In function `mode_show':
namespace_devs.c:(.text+0xa196): undefined reference to `is_nd_dax'
drivers/nvdimm/built-in.o: In function `nvdimm_namespace_common_probe':
(.text+0xa55f): undefined reference to `is_nd_dax'
drivers/nvdimm/built-in.o: In function `nvdimm_namespace_common_probe':
(.text+0xa56e): undefined reference to `to_nd_dax'

This reverts the earlier fix, making NVDIMM_DAX a 'bool' option again
as it should be (it gets linked into the libnvdimm module). To fix
the original problem, I'm adding a dependency on LIBNVDIMM to
DEV_DAX_PMEM, which ensures we can't have that one built-in if the
rest is a module.

Fixes: 4e65e938 ("/dev/dax: fix Kconfig dependency build breakage")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

ACPI Clear Uncorrectable Error DSM function may fail or may be
unsupported on a platform.  pmem_clear_poison() returns without clearing
badblocks in such cases.  This failure is detected at the next read
(-EIO).

This behavior can lead to an issue when user keeps writing but does not
read immediately.  For instance, flight recorder file may be only read
when it is necessary for troubleshooting.

Change pmem_do_bvec() and pmem_clear_poison() to return -EIO so that
filesystem can log an error message on a write error.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

If the kcalloc() fails then "devs" can be NULL and we dereference it
checking "devs[i]".

Fixes: 1b40e09a ('libnvdimm: blk labels and namespace instantiation')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The function dax_pmem_probe() in drivers/dax/pmem.c is compiled under the
CONFIG_DEV_DAX_PMEM tri-state config option.  This config option currently
only depends on CONFIG_NVDIMM_DAX, a bool, which means that the following
configuration is possible:

CONFIG_LIBNVDIMM=m
...
CONFIG_NVDIMM_DAX=y
CONFIG_DEV_DAX=y
CONFIG_DEV_DAX_PMEM=y

With this config LIBNVDIMM is compiled as a module with NVDIMM_DAX=y just
meaning that we will compile drivers/nvdimm/dax_devs.c into that module.
However, dax_pmem_probe() depends on several symbols defined in
drivers/nvdimm/dax_devs.c, which results in the following build errors:

drivers/built-in.o: In function `dax_pmem_probe':
linux/drivers/dax/pmem.c:70: undefined reference to `to_nd_dax'
linux/drivers/dax/pmem.c:74: undefined reference to
`nvdimm_namespace_common_probe'
linux/drivers/dax/pmem.c:80: undefined reference to `devm_nsio_enable'
linux/drivers/dax/pmem.c:81: undefined reference to `nvdimm_setup_pfn'
linux/drivers/dax/pmem.c:84: undefined reference to `devm_nsio_disable'
linux/drivers/dax/pmem.c:122: undefined reference to `to_nd_region'
drivers/built-in.o: In function `dax_pmem_init':
linux/drivers/dax/pmem.c:147: undefined reference to `__nd_driver_register'

Fix this by making NVDIMM_DAX a tristate.  DEV_DAX_PMEM depends on
NVDIMM_DAX which depends on LIBNVDIMM.  Since they are all now tristates,
if LIBNVDIMM is built as a kernel module DEV_DAX_PMEM will be as well.
This prevents dax_devs.c from being built as a built-in while its
dependencies are in the libnvdimm.ko module.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Similar to BLK regions, publish new seed namespace devices to allow
unused PMEM region capacity to be consumed by additional namespaces.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that the rest of the infrastructure has been converted to handle
multi-pmem configurations, lift the artificial barrier at scan time.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Short-circuit doomed-to-fail label validation attempts by skipping
labels that are outside the given region.  For example a DIMM that has
multiple PMEM regions will waste time attempting to create namespaces
only to find that the interleave-set-cookie does not validate, e.g.:

    nd_region region6: invalid cookie in label: 73e608dc-47b9-4b2a-b5c7-2d55a32e0c2

Similar to how we skip BLK labels when performing PMEM validation we can
skip out-of-range labels early.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that we have nd_region_available_dpa() able to handle the presence
of multiple PMEM allocations in aliased PMEM regions, reuse that same
infrastructure to track allocations from free space.  In particular
handle allocating from an aliased PMEM region in the case where there
are dis-contiguous holes.  The allocation for BLK and PMEM are
documented in the space_valid() helper:

    BLK-space is valid as long as it does not precede a PMEM
    allocation in a given region. PMEM-space must be contiguous
    and adjacent to an existing existing allocation (if one
    exists).
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Instead of assuming that there will only ever be one allocated range at
the start of the region, account for additional namespaces that might
start at an offset from the region base.

After this change pmem namespaces now have a reason to carry an array of
resources similar to blk.  Unifying the resource tracking infrastructure
in nd_namespace_common is a future cleanup candidate.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

pmem devices are currently named /dev/pmem<region-index>. Preserve the
naming of the 0th device, but add a ".<namespace-index>" for other
devices.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The free dpa (dimm-physical-address) space calculation reports how much
free space is available with consideration for aliased BLK + PMEM
regions.  Recall that BLK capacity is allocated from high addresses and
PMEM is allocated from low addresses in their respective regions.

nd_region_available_dpa() accounts for the fact that the largest
encroachment (lowest starting address) into PMEM capacity by a BLK
allocation limits the available capacity to that point, regardless if
there is BLK allocation hole at a higher address.  Similarly, for the
multi-pmem case we need to track the largest encroachment (highest
 ending address) of a PMEM allocation in BLK capacity regardless of
whether there is an allocation hole that a BLK allocation could fill at
a lower address.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Add more determinism to initial namespace device-name assignments by
sorting the namespaces by starting dpa.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

If label scanning finds multiple valid pmem namespaces allow them to be
surfaced rather than fail namespace scanning. Support for creating
multiple namespaces per region is saved for a later patch.

Note that this adds some new error messages to clarify which of the pmem
namespaces in the set are potentially impacted by invalid labels.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

In preparation for allowing multiple namespace per pmem region, unify
blk and pmem label scanning.  Given that blk regions already support
multiple namespaces, teaching that path how to do pmem namespace
scanning is an incremental step towards multiple pmem namespace support.
This should be functionally equivalent to the previous state in that
stops after finding the first valid pmem label set.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The ability to translate a generic struct device pointer into a
namespace uuid is a useful utility as we go to unify the blk and pmem
label scanning paths.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

In preparation for enabling multiple namespaces per pmem region, convert
the label tracking to use a linked list.  In particular this will allow
select_pmem_id() to move labels from the unvalidated state to the
validated state.  Currently we only track one validated set per-region.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Before we add more libnvdimm-private fields to nd_mapping make it clear
which parameters are input vs libnvdimm internals. Use struct
nd_mapping_desc instead of struct nd_mapping in nd_region_desc and make
struct nd_mapping private to libnvdimm.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Existing implemenetation writes to all the flush hint addresses for a
given ND region. This is not necessary as the flushes are per imc and
not per DIMM. Search the mappings and clear out the duplicates at init
to avoid multiple flush to the same imc.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

nvdimm_clear_poison cleared the user-visible badblocks, and sent
commands to the NVDIMM to clear the areas marked as 'poison', but it
neglected to clear the same areas from the internal poison_list which is
used to marshal ARS results before sorting them by namespace. As a
result, once on-demand ARS functionality was added:

37b137ff nfit, libnvdimm: allow an ARS scrub to be triggered on demand

A scrub triggered from either sysfs or an MCE was found to be adding
stale entries that had been cleared from gendisk->badblocks, but were
still present in nvdimm_bus->poison_list. Additionally, the stale entries
could be triggered into producing stale disk->badblocks by simply disabling
and re-enabling the namespace or region.

This adds the missing step of clearing poison_list entries when clearing
poison, so that it is always in sync with badblocks.

Fixes: 37b137ff ("nfit, libnvdimm: allow an ARS scrub to be triggered on demand")
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

pmem_do_bvec used to kmap_atomic at the begin, and only unmap at the
end. Things like nvdimm_clear_poison may want to do nvdimm subsystem
bookkeeping operations that may involve taking locks or doing memory
allocations, and we can't do that from the atomic context. Reduce the
atomic context to just what needs it - the memcpy to/from pmem.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The definition of the flush hint table as:

	void __iomem *flush_wpq[0][0];

...passed the unit test, but is broken as flush_wpq[0][1] and
flush_wpq[1][0] refer to the same entry.  Fix this to use a helper that
calculates a slot in the table based on the geometry of flush hints in
the region.  This is important to get right since virtualization
solutions use this mechanism to trigger hypervisor flushes to platform
persistence.
Reported-by: NDave Jiang <dave.jiang@intel.com>
Tested-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

If platform firmware fails to populate unique / non-zero serial number
data for each nvdimm in an interleave-set it may cause pmem region
initialization to fail.  Add a debug message for this case.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The internal alloc_nvdimm_map() helper might fail, particularly if the
memory region is already busy.  Report request_mem_region() failures and
check for the failure.
Reported-by: NRyan Chen <ryan.chan105@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

nd_activate_region() iomaps any hint addresses required when activating
a region. To prevent duplicate mappings it checks the PFN of the hint to
be mapped against the PFNs of the already mapped hints. Unfortunately it
doesn't convert the PFN back into a physical address before passing it
to devm_nvdimm_ioremap(). Instead it applies PHYS_PFN a second time
which ends about as well as you would imagine.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Bad blocks can be injected via /sys/block/pmemN/badblocks. In a situation
where legacy pmem is being used or a pmem region created by using memmap
kernel parameter, the injected bad blocks are not cleared due to
nvdimm_clear_poison() failing from lack of ndctl function pointer. In
this case we need to just return as handled and allow the bad blocks to
be cleared rather than fail.
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

'ndctl list --buses --dimms' does not list any NVDIMM-Ns since
they are considered as idle.  ndctl checks if any driver is
attached to nmem device.  nvdimm_probe() always fails in
nvdimm_init_nsarea() since NVDIMM-Ns do not implement optinal
ND_CMD_GET_CONFIG_DATA command.

Change nvdimm_probe() to accept the case that the CONFIG_DATA
command is not implemented for NVDIMM-Ns.  The driver attaches
without ndd, which keeps it no-op to the device.
Reported-by: NBrian Boylston <brian.boylston@hpe.com>
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Tested-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Per "ACPI 6.1 Section 9.20.3" NVDIMM devices, children of the ACPI0012
NVDIMM Root device, can receive health event notifications.

Given that these devices are precluded from registering a notification
handler via acpi_driver.acpi_device_ops (due to no _HID), we use
acpi_install_notify_handler() directly.  The registered handler,
acpi_nvdimm_notify(), triggers a poll(2) event on the nmemX/nfit/flags
sysfs attribute when a health event notification is received.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NToshi Kani <toshi.kani@hpe.com>
Reviewed-by: NVishal Verma <vishal.l.verma@intel.com>
Acked-by: NRafael J. Wysocki <rafael@kernel.org>
Reviewed-by: NToshi Kani <toshi.kani@hpe.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

To be consistent with other namespaces, expose a 'size' attribute for
BTT devices also.

Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: NLinda Knippers <linda.knippers@hpe.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Since commit 63a4cc24, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.

No intended functional changes in this commit.
Signed-off-by: NJens Axboe <axboe@fb.com>

Commit abf54548 changed it from an 'rw' flags type to the
newer ops based interface, but now we're effectively leaking
some bdev internals to the rest of the kernel. Since we only
care about whether it's a read or a write at that level, just
pass in a bool 'is_write' parameter instead.

Then we can also move op_is_write() and friends back under
CONFIG_BLOCK protection.
Reviewed-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The rw_page users were not converted to use bio/req ops. As a result
bdev_write_page is not passing down REQ_OP_WRITE and the IOs will
be sent down as reads.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Fixes: 4e1b2d52 ("block, fs, drivers: remove REQ_OP compat defs and related code")

Modified by me to:

1) Drop op_flags passing into ->rw_page(), as we don't use it.
2) Make op_is_write() and friends safe to use for !CONFIG_BLOCK
Signed-off-by: NJens Axboe <axboe@fb.com>

The __nd_device_register() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Normally, an ARS (Address Range Scrub) only happens at
boot/initialization time. There can however arise situations where a
bus-wide rescan is needed - notably, in the case of discovering a latent
media error, we should do a full rescan to figure out what other sectors
are bad, and thus potentially avoid triggering an mce on them in the
future. Also provide a sysfs trigger to start a bus-wide scrub.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

A recent effort to add a new nvdimm bus provider attribute highlighted a
race between interrogating nvdimm_bus->nd_desc and nvdimm_bus tear down.
The typical way to handle these races is to take the device_lock() in
the attribute method and validate that the device is still active.  In
order for a device to be 'active' it needs to be associated with a
driver.  So, we create the small boilerplate for a driver and register
nvdimm_bus devices on the 'nvdimm_bus_type' bus.

A result of this change is that ndbusX devices now appear under
/sys/bus/nd/devices.  In fact this makes /sys/class/nd somewhat
redundant, but removing that will need to take a long deprecation period
given its use by ndctl binaries in the field.

This change naturally pulls code from drivers/nvdimm/core.c to
drivers/nvdimm/bus.c, so it is a nice code organization clean-up as
well.

Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Prefix the sector number being cleared with a '0x' to make it clear that
this is a hex value.
Signed-off-by: NVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Let the provider module be explicitly passed in rather than implicitly
assumed by the module that calls nvdimm_bus_register().  This is in
preparation for unifying the nfit and nfit_test driver teardown paths.
Reviewed-by: NLee, Chun-Yi <jlee@suse.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Currently, presence of direct_access() in block_device_operations
indicates support of DAX on its block device.  Because
block_device_operations is instantiated with 'const', this DAX
capablity may not be enabled conditinally.

In preparation for supporting DAX to device-mapper devices, add
QUEUE_FLAG_DAX to request_queue flags to advertise their DAX
support.  This will allow to set the DAX capability based on how
mapped device is composed.
Signed-off-by: NToshi Kani <toshi.kani@hpe.com>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <linux-s390@vger.kernel.org>
Signed-off-by: NJens Axboe <axboe@fb.com>

The __pmem address space was meant to annotate codepaths that touch
persistent memory and need to coordinate a call to wmb_pmem().  Now that
wmb_pmem() is gone, there is little need to keep this annotation.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>