platform/x86: Intel PMT Crashlog capability driver

Add support for the Intel Platform Monitoring Technology crashlog
interface. This interface provides a few sysfs values to allow for
controlling the crashlog telemetry interface as well as a character
driver to allow for mapping the crashlog memory region so that it can be
accessed after a crashlog has been recorded.

This driver is meant to only support the server version of the crashlog
which is identified as crash_type 1 with a version of zero. Currently no
other types are supported.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/ABI/testing/sysfs-class-intel_pmt

@@ -52,3 +52,68 @@ Contact:	David Box <david.e.box@linux.intel.com>
 Description:
 		(RO) The offset of telemetry region in bytes that corresponds to
 		the mapping for the telem file.
+
+What:		/sys/class/intel_pmt/crashlog<x>
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Description:
+		The crashlog<x> directory contains files for configuring an
+		instance of a PMT crashlog device that can perform crash data
+		recording. Each crashlog<x> device has an associated crashlog
+		file. This file can be opened and mapped or read to access the
+		resulting crashlog buffer. The register layout for the buffer
+		can be determined from an XML file of specified GUID for the
+		parent device.
+
+What:		/sys/class/intel_pmt/crashlog<x>/crashlog
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	David Box <david.e.box@linux.intel.com>
+Description:
+		(RO) The crashlog buffer for this crashlog device. This file
+		may be mapped or read to obtain the data.
+
+What:		/sys/class/intel_pmt/crashlog<x>/guid
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Description:
+		(RO) The GUID for this crashlog device. The GUID identifies the
+		version of the XML file for the parent device that should be
+		used to determine the register layout.
+
+What:		/sys/class/intel_pmt/crashlog<x>/size
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Description:
+		(RO) The length of the result buffer in bytes that corresponds
+		to the size for the crashlog buffer.
+
+What:		/sys/class/intel_pmt/crashlog<x>/offset
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Description:
+		(RO) The offset of the buffer in bytes that corresponds
+		to the mapping for the crashlog device.
+
+What:		/sys/class/intel_pmt/crashlog<x>/enable
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Description:
+		(RW) Boolean value controlling if the crashlog functionality
+		is enabled for the crashlog device.
+
+What:		/sys/class/intel_pmt/crashlog<x>/trigger
+Date:		October 2020
+KernelVersion:	5.10
+Contact:	Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Description:
+		(RW) Boolean value controlling the triggering of the crashlog
+		device node. When read it provides data on if the crashlog has
+		been triggered. When written to it can be used to either clear
+		the current trigger by writing false, or to trigger a new
+		event if the trigger is not currently set.

drivers/platform/x86/Kconfig

@@ -1385,6 +1385,17 @@ config INTEL_PMT_TELEMETRY
 	  To compile this driver as a module, choose M here: the module
 	  will be called intel_pmt_telemetry.
 
+config INTEL_PMT_CRASHLOG
+	tristate "Intel Platform Monitoring Technology (PMT) Crashlog driver"
+	select INTEL_PMT_CLASS
+	help
+	  The Intel Platform Monitoring Technology (PMT) crashlog driver provides
+	  access to hardware crashlog capabilities on devices that support the
+	  feature.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called intel_pmt_crashlog.
+
 config INTEL_PUNIT_IPC
 	tristate "Intel P-Unit IPC Driver"
 	help

drivers/platform/x86/Makefile

@@ -142,6 +142,7 @@ obj-$(CONFIG_INTEL_MRFLD_PWRBTN)	+= intel_mrfld_pwrbtn.o
 obj-$(CONFIG_INTEL_PMC_CORE)		+= intel_pmc_core.o intel_pmc_core_pltdrv.o
 obj-$(CONFIG_INTEL_PMT_CLASS)		+= intel_pmt_class.o
 obj-$(CONFIG_INTEL_PMT_TELEMETRY)	+= intel_pmt_telemetry.o
+obj-$(CONFIG_INTEL_PMT_CRASHLOG)	+= intel_pmt_crashlog.o
 obj-$(CONFIG_INTEL_PUNIT_IPC)		+= intel_punit_ipc.o
 obj-$(CONFIG_INTEL_SCU_IPC)		+= intel_scu_ipc.o
 obj-$(CONFIG_INTEL_SCU_PCI)		+= intel_scu_pcidrv.o