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authorJoey Gouly <joey.gouly@arm.com>2021-12-10 16:54:30 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2021-12-13 18:52:59 +0000
commit5c13f042e73200b50573ace63e1a6b94e2917616 (patch)
treede22698982896d4808630041ca8797f2b522ca3b /Documentation/arm64
parentd58071a8a76d779eedab38033ae4c821c30295a5 (diff)
downloadlwn-5c13f042e73200b50573ace63e1a6b94e2917616.tar.gz
lwn-5c13f042e73200b50573ace63e1a6b94e2917616.zip
arm64: cpufeature: add HWCAP for FEAT_AFP
Add a new HWCAP to detect the Alternate Floating-point Behaviour feature (FEAT_AFP), introduced in Armv8.7. Also expose this to userspace in the ID_AA64MMFR1_EL1 feature register. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Will Deacon <will@kernel.org> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20211210165432.8106-2-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'Documentation/arm64')
-rw-r--r--Documentation/arm64/cpu-feature-registers.rst9
-rw-r--r--Documentation/arm64/elf_hwcaps.rst4
2 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst
index 9f9b8fd06089..1b19d20c2dbd 100644
--- a/Documentation/arm64/cpu-feature-registers.rst
+++ b/Documentation/arm64/cpu-feature-registers.rst
@@ -275,6 +275,15 @@ infrastructure:
| SVEVer | [3-0] | y |
+------------------------------+---------+---------+
+ 8) ID_AA64MMFR1_EL1 - Memory model feature register 1
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | AFP | [47-44] | y |
+ +------------------------------+---------+---------+
+
+
Appendix I: Example
-------------------
diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst
index af106af8e1c0..247728d37911 100644
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst
@@ -251,6 +251,10 @@ HWCAP2_ECV
Functionality implied by ID_AA64MMFR0_EL1.ECV == 0b0001.
+HWCAP2_AFP
+
+ Functionality implied by ID_AA64MFR1_EL1.AFP == 0b0001.
+
4. Unused AT_HWCAP bits
-----------------------