diff options
| author | Ionela Voinescu <ionela.voinescu@arm.com> | 2020-03-05 09:06:21 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-06 16:02:49 +0000 |
| commit | 2c9d45b43c39e26fd2a73f2203321cdaee98b58b (patch) | |
| tree | 296a8b9aea33f75c713c408765ffe935bad920bd /arch/arm64/Kconfig | |
| parent | f8788d86ab28f61f7b46eb6be375f8a726783636 (diff) | |
| download | lwn-2c9d45b43c39e26fd2a73f2203321cdaee98b58b.tar.gz lwn-2c9d45b43c39e26fd2a73f2203321cdaee98b58b.zip | |
arm64: add support for the AMU extension v1
The activity monitors extension is an optional extension introduced
by the ARMv8.4 CPU architecture. This implements basic support for
version 1 of the activity monitors architecture, AMUv1.
This support includes:
- Extension detection on each CPU (boot, secondary, hotplugged)
- Register interface for AMU aarch64 registers
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/Kconfig')
| -rw-r--r-- | arch/arm64/Kconfig | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0b30e884e088..fa4e3737149c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1517,6 +1517,33 @@ config ARM64_PTR_AUTH endmenu +menu "ARMv8.4 architectural features" + +config ARM64_AMU_EXTN + bool "Enable support for the Activity Monitors Unit CPU extension" + default y + help + The activity monitors extension is an optional extension introduced + by the ARMv8.4 CPU architecture. This enables support for version 1 + of the activity monitors architecture, AMUv1. + + To enable the use of this extension on CPUs that implement it, say Y. + + Note that for architectural reasons, firmware _must_ implement AMU + support when running on CPUs that present the activity monitors + extension. The required support is present in: + * Version 1.5 and later of the ARM Trusted Firmware + + For kernels that have this configuration enabled but boot with broken + firmware, you may need to say N here until the firmware is fixed. + Otherwise you may experience firmware panics or lockups when + accessing the counter registers. Even if you are not observing these + symptoms, the values returned by the register reads might not + correctly reflect reality. Most commonly, the value read will be 0, + indicating that the counter is not enabled. + +endmenu + menu "ARMv8.5 architectural features" config ARM64_E0PD |