ACPI: tables: introduce support for FPDT table
ACPI Firmware Performance Data Table (FPDT) provides information about
firmware performance during system boot, S3 suspend and S3 resume.
Have the kernel parse the FPDT table, and expose the firmware
performance data to userspace as sysfs attributes under
/sys/firmware/acpi/fpdt/.
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi
index b16d30a..819939d 100644
--- a/Documentation/ABI/testing/sysfs-firmware-acpi
+++ b/Documentation/ABI/testing/sysfs-firmware-acpi
@@ -1,3 +1,46 @@
+What: /sys/firmware/acpi/fpdt/
+Date: Jan 2021
+Contact: Zhang Rui <rui.zhang@intel.com>
+Description:
+ ACPI Firmware Performance Data Table (FPDT) provides
+ information for firmware performance data for system boot,
+ S3 suspend and S3 resume. This sysfs entry contains the
+ performance data retrieved from the FPDT.
+
+ boot:
+ firmware_start_ns: Timer value logged at the beginning
+ of firmware image execution. In nanoseconds.
+ bootloader_load_ns: Timer value logged just prior to
+ loading the OS boot loader into memory.
+ In nanoseconds.
+ bootloader_launch_ns: Timer value logged just prior to
+ launching the currently loaded OS boot loader
+ image. In nanoseconds.
+ exitbootservice_start_ns: Timer value logged at the
+ point when the OS loader calls the
+ ExitBootServices function for UEFI compatible
+ firmware. In nanoseconds.
+ exitbootservice_end_ns: Timer value logged at the point
+ just prior to the OS loader gaining control
+ back from the ExitBootServices function for
+ UEFI compatible firmware. In nanoseconds.
+ suspend:
+ suspend_start_ns: Timer value recorded at the previous
+ OS write to SLP_TYP upon entry to S3. In
+ nanoseconds.
+ suspend_end_ns: Timer value recorded at the previous
+ firmware write to SLP_TYP used to trigger
+ hardware entry to S3. In nanoseconds.
+ resume:
+ resume_count: A count of the number of S3 resume cycles
+ since the last full boot sequence.
+ resume_avg_ns: Average timer value of all resume cycles
+ logged since the last full boot sequence,
+ including the most recent resume. In nanoseconds.
+ resume_prev_ns: Timer recorded at the end of the previous
+ platform runtime firmware S3 resume, just prior to
+ handoff to the OS waking vector. In nanoseconds.
+
What: /sys/firmware/acpi/bgrt/
Date: January 2012
Contact: Matthew Garrett <mjg@redhat.com>
