Re: [PATCH RFC platform-next 8/8] Documentation/ABI: Add new line card attributes for mlxreg-io sysfs interfaces

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 2/3/21 6:36 PM, Vadim Pasternak wrote:
> Add documentation for the new attributes for line cards:
> - CPLDs versioning.
> - Write protection control for 'nvram' devices.
> - Line card reset reasons.
> - Enabling burning of FPGA and CPLDs.
> - Enabling burning of FPGA and gearbox SPI flashes,
> - Enabling power of whole line card.
> - Enabling power of QSFP ports equipped on line card.
> - The maximum powered required for line card feeding.
> - Line card configuration Id.
> 
> Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
> ---
>  Documentation/ABI/stable/sysfs-driver-mlxreg-io | 92 +++++++++++++++++++++++++
>  1 file changed, 92 insertions(+)
> 
> diff --git a/Documentation/ABI/stable/sysfs-driver-mlxreg-io b/Documentation/ABI/stable/sysfs-driver-mlxreg-io
> index 1d1a8ee59534..a22e9d6c0904 100644
> --- a/Documentation/ABI/stable/sysfs-driver-mlxreg-io
> +++ b/Documentation/ABI/stable/sysfs-driver-mlxreg-io
> @@ -326,3 +326,95 @@ Description:	This file unlocks system after hardware or firmware thermal
>  		locking.
>  
>  		The file is read/write.
> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/cpld1_pn
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/cpld1_version
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/cpld1_version_min
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files show with which CPLD major and minor versions
> +		and part number has been burned CPLD device on line card.
> +
> +		The files are read only.
> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/fpga1_pn
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/fpga1_version
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/fpga1_version_min
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files show with which FPGA major and minor versions
> +		and part number has been burned FPGA device on line card.
> +
> +		The files are read only.
> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/ini_wp
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/vpd_wp
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files allow to overwrite line card VPD and firmware blob
> +		hardware write protection mode. When attribute is set 1 - write
> +		protection is disabled, when 0 - enabled. By default both are
> +		write protected.
> +
> +		The files are read/write.

This seems to have some serious security implications. IMHO this should be tie into the
kernel's new(ish) lockdown system, so that if the system is in locked-down mode writing
these will not be allowed.

> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/reset_aux_pwr_or_ref
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/reset_dc_dc_pwr_fail
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/reset_fpga_not_done
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/reset_from_chassis
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/reset_line_card
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/reset_pwr_off_from_chassis
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files show the line reset cause, as following: power
> +		auxiliary outage or power refresh, DC-to-DC power failure, FPGA reset
> +		failed, line card reset failed, power off from chassis.
> +		Value 1 in file means this is reset cause, 0 - otherwise. Only one of
> +		the above causes could be 1 at the same time, representing only last
> +		reset cause.
> +
> +		The files are read only.
> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/cpld_upgrade_en
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/fpga_upgrade_en
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files allow CPLD and FPGA burning. Value 1 in file means burning
> +		is enabled, 0 - otherwise.
> +
> +		The files are read/write.

Same remark as above.

> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/qsfp_pwr_en
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/pwr_en
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files allow to power on/off all QSFP ports and whole line card.
> +		The attributes are set 1 for power on, 0 - for power off.
> +
> +		The files are read/write.
> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/agb_spi_burn_en
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/fpga_spi_burn_en
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files allow gearboxes and FPGA SPI flash burning.
> +		The attributes are set 1 to enable burning, 0 - to disable.
> +
> +		The file is read/write.

Same remark as above.

> +
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/max_power
> +What:		/sys/devices/platform/mlxplat/i2c_mlxcpld.*/i2c-*/i2c-*/i2c-*/*-0032/mlxreg-io.*/hwmon/hwmon*/config
> +Date:		March 2021
> +KernelVersion:	5.12
> +Contact:	Vadim Pasternak <vadimp@nvidia.com>
> +Description:	These files provide the maximum powered required for line card
> +		feeding and line card configuration Id.
> +
> +		The files are read only.
> 

Regards,

Hans