nvme: host: hwmon: constify pointers to hwmon_channel_info

Statically allocated array of pointed to hwmon_channel_info can be made
const for safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvme-pci: add quirk for missing secondary temperature thresholds

On Kingston KC3000 and Kingston FURY Renegade (both have the same PCI
IDs) accessing temp3_{min,max} fails with an invalid field error (note
that there is no problem setting the thresholds for temp1).

This contradicts the NVM Express Base Specification 2.0b, page 292:

The over temperature threshold and under temperature threshold
features shall be implemented for all implemented temperature sensors
(i.e., all Temperature Sensor fields that report a non-zero value).

Define NVME_QUIRK_NO_SECONDARY_TEMP_THRESH that disables the thresholds
for all but the composite temperature and set it for this device.

Signed-off-by: Hristo Venev <hristo@venev.name>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme-hwmon: kmalloc the NVME SMART log buffer

Recent commit 52fde2c07da6 ("nvme: set dma alignment to dword") has
caused a regression on our platform.

It turned out that the nvme_get_log() method invocation caused the
nvme_hwmon_data structure instance corruption. In particular the
nvme_hwmon_data.ctrl pointer was overwritten either with zeros or with
garbage. After some research we discovered that the problem happened
even before the actual NVME DMA execution, but during the buffer mapping.
Since our platform is DMA-noncoherent, the mapping implied the cache-line
invalidations or write-backs depending on the DMA-direction parameter.
In case of the NVME SMART log getting the DMA was performed
from-device-to-memory, thus the cache-invalidation was activated during
the buffer mapping. Since the log-buffer isn't cache-line aligned, the
cache-invalidation caused the neighbour data to be discarded. The
neighbouring data turned to be the data surrounding the buffer in the
framework of the nvme_hwmon_data structure.

In order to fix that we need to make sure that the whole log-buffer is
defined within the cache-line-aligned memory region so the
cache-invalidation procedure wouldn't involve the adjacent data. One of
the option to guarantee that is to kmalloc the DMA-buffer [1]. Seeing the
rest of the NVME core driver prefer that method it has been chosen to fix
this problem too.

Note after a deeper researches we found out that the denoted commit wasn't
a root cause of the problem. It just revealed the invalidity by activating
the DMA-based NVME SMART log getting performed in the framework of the
NVME hwmon driver. The problem was here since the initial commit of the
driver.

[1] Documentation/core-api/dma-api-howto.rst

Fixes: 400b6a7b13a3 ("nvme: Add hardware monitoring support")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme-hwmon: consistently ignore errors from nvme_hwmon_init

An NVMe controller works perfectly fine even when the hwmon
initialization fails. Stop returning errors that do not come from a
controller reset from nvme_hwmon_init to handle this case consistently.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>

nvme-hwmon: Return error code when registration fails

The hwmon pointer wont be NULL if the registration fails. Though the
exit code path will assign it to ctrl->hwmon_device. Later
nvme_hwmon_exit() will try to free the invalid pointer. Avoid this by
returning the error code from hwmon_device_register_with_info().

Fixes: ed7770f66286 ("nvme/hwmon: rework to avoid devm allocation")
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme-hwmon: rework to avoid devm allocation

The original design to use device-managed resource allocation
doesn't really work as the NVMe controller has a vastly different
lifetime than the hwmon sysfs attributes, causing warning about
duplicate sysfs entries upon reconnection.
This patch reworks the hwmon allocation to avoid device-managed
resource allocation, and uses the NVMe controller as parent for
the sysfs attributes.

Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Enzo Matsumiya <ematsumiya@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme: return errors for hwmon init

Initializing the nvme hwmon retrieves a log from the controller. If the
controller is broken, we need to return the appropriate error so that
subsequent initialization doesn't attempt to continue.

Reported-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme-hwmon: log the controller device name

Stay consistent with the rest of the driver

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme: support for multiple Command Sets Supported and Effects log pages

The Commands Supported and Effects log page was extended with a CSI
field that enables the host to query the log page for each command set
supported. Retrieve this log page for each command set that an attached
namespace supports, and save a pointer to that log in the namespace head.

Reviewed-by: Matias Bjørling <matias.bjorling@wdc.com>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <keith.busch@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme: hwmon: switch to use <linux/units.h> helpers

This switches the nvme driver to use kelvin_to_millicelsius() and
millicelsius_to_kelvin() in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-8-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nvme: hwmon: add quirk to avoid changing temperature threshold

This adds a new quirk NVME_QUIRK_NO_TEMP_THRESH_CHANGE to avoid changing
the value of the temperature threshold feature for specific devices that
show undesirable behavior.

Guenter reported:

"On my Intel NVME drive (SSDPEKKW512G7), writing any minimum limit on the
Composite temperature sensor results in a temperature warning, and that
warning is sticky until I reset the controller.

It doesn't seem to matter which temperature I write; writing -273000 has
the same result."

The Intel NVMe has the latest firmware version installed, so this isn't
a problem that was ever fixed.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Jean Delvare <jdelvare@suse.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvme: hwmon: provide temperature min and max values for each sensor

According to the NVMe specification, the over temperature threshold and
under temperature threshold features shall be implemented for Composite
Temperature if a non-zero WCTEMP field value is reported in the Identify
Controller data structure. The features are also implemented for all
implemented temperature sensors (i.e., all Temperature Sensor fields that
report a non-zero value).

This provides the over temperature threshold and under temperature
threshold for each sensor as temperature min and max values of hwmon
sysfs attributes.

The WCTEMP is already provided as a temperature max value for Composite
Temperature, but this change isn't incompatible. Because the default
value of the over temperature threshold for Composite Temperature is
the WCTEMP.

Now the alarm attribute for Composite Temperature indicates one of the
temperature is outside of a temperature threshold. Because there is only
a single bit in Critical Warning field that indicates a temperature is
outside of a threshold.

Example output from the "sensors" command:

nvme-pci-0100
Adapter: PCI adapter
Composite: +33.9°C (low = -273.1°C, high = +69.8°C)
(crit = +79.8°C)
Sensor 1: +34.9°C (low = -273.1°C, high = +65261.8°C)
Sensor 2: +31.9°C (low = -273.1°C, high = +65261.8°C)
Sensor 5: +47.9°C (low = -273.1°C, high = +65261.8°C)

This also adds helper macros for kelvin from/to milli Celsius conversion,
and replaces the repeated code in hwmon.c.

Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Jean Delvare <jdelvare@suse.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

nvme: Add hardware monitoring support

nvme devices report temperature information in the controller information
(for limits) and in the smart log. Currently, the only means to retrieve
this information is the nvme command line interface, which requires
super-user privileges.

At the same time, it would be desirable to be able to use NVMe temperature
information for thermal control.

This patch adds support to read NVMe temperatures from the kernel using the
hwmon API and adds temperature zones for NVMe drives. The thermal subsystem
can use this information to set thermal policies, and userspace can access
it using libsensors and/or the "sensors" command.

Example output from the "sensors" command:

nvme0-pci-0100
Adapter: PCI adapter
Composite: +39.0°C (high = +85.0°C, crit = +85.0°C)
Sensor 1: +39.0°C
Sensor 2: +41.0°C

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Keith Busch <kbusch@kernel.org>