Merge branch 'acpi-pfrut'

Merge support for the Platform Firmware Runtime Update and Telemetry
interface based on ACPI.

The interface provided here allows updating certain pieces of the
platform firmware without restarting the system and collecting
platform firmware telemetry data.

This also includes a utility for accesing the new interface from user
space.

* acpi-pfrut:
  ACPI: pfr_telemetry: Fix info leak in pfrt_log_ioctl()
  ACPI: pfr_update: Fix return value check in pfru_write()
  ACPI: tools: Introduce utility for firmware updates/telemetry
  ACPI: Introduce Platform Firmware Runtime Telemetry driver
  ACPI: Introduce Platform Firmware Runtime Update device driver
  efi: Introduce EFI_FIRMWARE_MANAGEMENT_CAPSULE_HEADER and corresponding structures

Documentation/userspace-api/ioctl/ioctl-number.rst

@@ -367,6 +367,7 @@ Code  Seq#    Include File                                           Comments
                                                                      <mailto:aherrman@de.ibm.com>
 0xE5  00-3F  linux/fuse.h
 0xEC  00-01  drivers/platform/chrome/cros_ec_dev.h                   ChromeOS EC driver
+0xEE  00-09  uapi/linux/pfrut.h                                      Platform Firmware Runtime Update and Telemetry
 0xF3  00-3F  drivers/usb/misc/sisusbvga/sisusb.h                     sisfb (in development)
                                                                      <mailto:thomas@winischhofer.net>
 0xF6  all                                                            LTTng Linux Trace Toolkit Next Generation

drivers/acpi/Kconfig

@@ -517,6 +517,28 @@ config ACPI_CONFIGFS
 	  userspace. The configurable ACPI groups will be visible under
 	  /config/acpi, assuming configfs is mounted under /config.
 
+config ACPI_PFRUT
+	tristate "ACPI Platform Firmware Runtime Update and Telemetry"
+	depends on 64BIT
+	help
+	  This mechanism allows certain pieces of the platform firmware
+	  to be updated on the fly while the system is running (runtime)
+	  without the need to restart it, which is key in the cases when
+	  the system needs to be available 100% of the time and it cannot
+	  afford the downtime related to restarting it, or when the work
+	  carried out by the system is particularly important, so it cannot
+	  be interrupted, and it is not practical to wait until it is complete.
+
+	  The existing firmware code can be modified (driver update) or
+	  extended by adding new code to the firmware (code injection).
+
+	  Besides, the telemetry driver allows user space to fetch telemetry
+	  data from the firmware with the help of the Platform Firmware Runtime
+	  Telemetry interface.
+
+	  To compile the drivers as modules, choose M here:
+	  the modules will be called pfr_update and pfr_telemetry.
+
 if ARM64
 source "drivers/acpi/arm64/Kconfig"
 

drivers/acpi/Makefile

@@ -103,6 +103,7 @@ obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
 obj-$(CONFIG_ACPI_SPCR_TABLE)	+= spcr.o
 obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
 obj-$(CONFIG_ACPI_PPTT) 	+= pptt.o
+obj-$(CONFIG_ACPI_PFRUT)	+= pfr_update.o pfr_telemetry.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o