From 9cf75647235ad243acc7a585696ccb7b5ff54b36 Mon Sep 17 00:00:00 2001 From: Chris Kay Date: Tue, 17 Aug 2021 16:24:57 +0100 Subject: [PATCH] docs(amu): add AMU documentation This change adds some documentation on the AMU and its purpose. This is expanded on in later patches. Change-Id: If2834676790938d8da5ea2ceba37b674f6cc0f01 Signed-off-by: Chris Kay --- docs/components/activity-monitors.rst | 15 +++++++++++++++ docs/components/index.rst | 1 + docs/global_substitutions.txt | 2 ++ docs/glossary.rst | 4 ++++ 4 files changed, 22 insertions(+) create mode 100644 docs/components/activity-monitors.rst diff --git a/docs/components/activity-monitors.rst b/docs/components/activity-monitors.rst new file mode 100644 index 000000000..57d81f88b --- /dev/null +++ b/docs/components/activity-monitors.rst @@ -0,0 +1,15 @@ +Activity Monitors +================= + +FEAT_AMUv1 of the Armv8-A architecture introduces the Activity Monitors +extension. This extension describes the architecture for the Activity Monitor +Unit (|AMU|), an optional non-invasive component for monitoring core events +through a set of 64-bit counters. + +When the ``ENABLE_AMU=1`` build option is provided, Trusted Firmware-A sets up +the |AMU| prior to its exit from EL3, and will save and restore architected +|AMU| counters as necessary upon suspend and resume. + +-------------- + +*Copyright (c) 2021, Arm Limited. All rights reserved.* diff --git a/docs/components/index.rst b/docs/components/index.rst index f349d8dcc..e46751651 100644 --- a/docs/components/index.rst +++ b/docs/components/index.rst @@ -7,6 +7,7 @@ Components :numbered: spd/index + activity-monitors arm-sip-service debugfs-design exception-handling diff --git a/docs/global_substitutions.txt b/docs/global_substitutions.txt index 24ac8300e..a70f15e3d 100644 --- a/docs/global_substitutions.txt +++ b/docs/global_substitutions.txt @@ -1,5 +1,7 @@ .. |AArch32| replace:: :term:`AArch32` .. |AArch64| replace:: :term:`AArch64` +.. |AMU| replace:: :term:`AMU` +.. |AMUs| replace:: :term:`AMUs ` .. |API| replace:: :term:`API` .. |BTI| replace:: :term:`BTI` .. |CoT| replace:: :term:`CoT` diff --git a/docs/glossary.rst b/docs/glossary.rst index f4912f518..a062319ce 100644 --- a/docs/glossary.rst +++ b/docs/glossary.rst @@ -15,6 +15,10 @@ You can find additional definitions in the `Arm Glossary`_. AArch64 64-bit execution state of the ARMv8 ISA + AMU + Activity Monitor Unit, a hardware monitoring unit introduced by FEAT_AMUv1 + that exposes CPU core runtime metrics as a set of counter registers. + API Application Programming Interface