hwmon: (peci/dimmtemp) Bump timeout

The PECI CPU sensors are available as soon as the CPU is powered,
however the PECI DIMM sensors are available after DRAM has been
trained and thresholds have been written by host firmware.

The default timeout of 30 seconds isn't enough for modern multisocket
platforms utilizing DDR5 memory to bring up the memory and enable PECI
sensor data.
Bump the default timeout to 10 minutes in case the system starts
without cached DDR5 training data.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Link: https://lore.kernel.org/r/20231130090422.2535542-1-patrick.rudolph@9elements.com
[groeck: List affected driver in patch subject]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (peci/dimmtemp) Add Sapphire Rapids support

Extend the functionality of hwmon (peci/dimmtemp) for Sapphire Rapids
platform.

Add the corresponding Sapphire Rapids ID and threshold code.

The patch has been tested on a 4S system with 64 DIMMs installed.
Verified read of DIMM temperature thresholds & temperature.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <Naresh.Solanki@9elements.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20230725104354.33920-3-Naresh.Solanki@9elements.com

hwmon: (dimmtemp) Support more than 32 DIMMs

This patch introduces support for handling more than 32 DIMMs by
utilizing bitmap operations. The changes ensure that the driver can
handle a higher number of DIMMs efficiently.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Link: https://lore.kernel.org/r/20230711152144.755177-1-Naresh.Solanki@9elements.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: peci: 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>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (dimmtemp) Fix bitmap handling

Building arm:allmodconfig may fail with the following error.

In function 'fortify_memcpy_chk',
inlined from 'bitmap_copy' at include/linux/bitmap.h:261:2,
inlined from 'bitmap_copy_clear_tail' at include/linux/bitmap.h:270:2,
inlined from 'bitmap_from_u64' at include/linux/bitmap.h:622:2,
inlined from 'check_populated_dimms' at
drivers/hwmon/peci/dimmtemp.c:284:2:
include/linux/fortify-string.h:344:25: error:
call to '__write_overflow_field' declared with attribute warning:
detected write beyond size of field (1st parameter)

The problematic code is
bitmap_from_u64(priv->dimm_mask, dimm_mask);

dimm_mask is declared as u64, but the bitmap in priv->dimm_mask is only
24 bit wide. On 32-bit systems, this results in writes over the end of
the bitmap.

Fix the problem by using u32 instead of u64 for dimm_mask. This is
currently sufficient, and a compile time check to ensure that the number
of dimms does not exceed the bit map size is already in place.

Fixes: 73bc1b885dae ("hwmon: peci: Add dimmtemp driver")
Cc: Iwona Winiarska <iwona.winiarska@intel.com>
Reviewed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (peci/dimmtemp) Use HWMON_CHANNEL_INFO macro

The HWMON_CHANNEL_INFO macro simplifies the code, reduces the likelihood
of errors, and makes the code easier to read.

The conversion was done automatically with coccinelle. The semantic patch
used to make this change is as follows.

@s@
identifier i,j,ty;
@@

-struct hwmon_channel_info j = {
- .type = ty,
- .config = i,
-};

@r@
initializer list elements;
identifier s.i;
@@

-u32 i[] = {
- elements,
- 0
-};

@script:ocaml t@
ty << s.ty;
elements << r.elements;
shorter;
elems;
@@

shorter :=
make_ident (List.hd(List.rev (Str.split (Str.regexp "_") ty)));
elems :=
make_ident
(String.concat ","
(List.map (fun x -> Printf.sprintf "\n\t\t\t %s" x)
(Str.split (Str.regexp " , ") elements)))

@@
identifier s.j,t.shorter;
identifier t.elems;
@@

- &j
+ HWMON_CHANNEL_INFO(shorter,elems)

This patch does not introduce functional changes. Many thanks to
Julia Lawall for providing the coccinelle script.

Cc: Iwona Winiarska <iwona.winiarska@intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: (peci) Use devm_delayed_work_autocancel() to simplify code

Use devm_delayed_work_autocancel() instead of hand writing it. This is
less verbose and saves a few lines of code.

devm_delayed_work_autocancel() uses devm_add_action() instead of
devm_add_action_or_reset(). This is fine, because if the underlying memory
allocation fails, no work has been scheduled yet. So there is nothing to
undo.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/fd277a708ede3882d7df6831f02d2e3c0cb813b8.1644781718.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

hwmon: peci: Add dimmtemp driver

Add peci-dimmtemp driver for Temperature Sensor on DIMM readings that
are accessible via the processor PECI interface.

The main use case for the driver (and PECI interface) is out-of-band
management, where we're able to obtain thermal readings from an external
entity connected with PECI, e.g. BMC on server platforms.

Co-developed-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-12-iwona.winiarska@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>