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authorWill Deacon <will@kernel.org>2025-05-27 12:26:43 +0100
committerWill Deacon <will@kernel.org>2025-05-27 12:26:43 +0100
commit53a087046ad9a9b3cea2e92f9c5a06011f6e78b0 (patch)
tree36dbf2bfd9e58467c2b5255e986df71f1daed3e3 /Documentation
parentMerge branch 'for-next/selftests' into for-next/core (diff)
parentarm64/fpsimd: Allow CONFIG_ARM64_SME to be selected (diff)
downloadwireguard-linux-53a087046ad9a9b3cea2e92f9c5a06011f6e78b0.tar.xz
wireguard-linux-53a087046ad9a9b3cea2e92f9c5a06011f6e78b0.zip
Merge branch 'for-next/sme-fixes' into for-next/core
* for-next/sme-fixes: (35 commits) arm64/fpsimd: Allow CONFIG_ARM64_SME to be selected arm64/fpsimd: ptrace: Gracefully handle errors arm64/fpsimd: ptrace: Mandate SVE payload for streaming-mode state arm64/fpsimd: ptrace: Do not present register data for inactive mode arm64/fpsimd: ptrace: Save task state before generating SVE header arm64/fpsimd: ptrace/prctl: Ensure VL changes leave task in a valid state arm64/fpsimd: ptrace/prctl: Ensure VL changes do not resurrect stale data arm64/fpsimd: Make clone() compatible with ZA lazy saving arm64/fpsimd: Clear PSTATE.SM during clone() arm64/fpsimd: Consistently preserve FPSIMD state during clone() arm64/fpsimd: Remove redundant task->mm check arm64/fpsimd: signal: Use SMSTOP behaviour in setup_return() arm64/fpsimd: Add task_smstop_sm() arm64/fpsimd: Factor out {sve,sme}_state_size() helpers arm64/fpsimd: Clarify sve_sync_*() functions arm64/fpsimd: ptrace: Consistently handle partial writes to NT_ARM_(S)SVE arm64/fpsimd: signal: Consistently read FPSIMD context arm64/fpsimd: signal: Mandate SVE payload for streaming-mode state arm64/fpsimd: signal: Clear PSTATE.SM when restoring FPSIMD frame only arm64/fpsimd: Do not discard modified SVE state ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/arch/arm64/sme.rst8
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/arch/arm64/sme.rst b/Documentation/arch/arm64/sme.rst
index b2fa01f85cb5..4cb38330e704 100644
--- a/Documentation/arch/arm64/sme.rst
+++ b/Documentation/arch/arm64/sme.rst
@@ -69,8 +69,8 @@ model features for SME is included in Appendix A.
vectors from 0 to VL/8-1 stored in the same endianness invariant format as is
used for SVE vectors.
-* On thread creation TPIDR2_EL0 is preserved unless CLONE_SETTLS is specified,
- in which case it is set to 0.
+* On thread creation PSTATE.ZA and TPIDR2_EL0 are preserved unless CLONE_VM
+ is specified, in which case PSTATE.ZA is set to 0 and TPIDR2_EL0 is set to 0.
2. Vector lengths
------------------
@@ -115,7 +115,7 @@ be zeroed.
5. Signal handling
-------------------
-* Signal handlers are invoked with streaming mode and ZA disabled.
+* Signal handlers are invoked with PSTATE.SM=0, PSTATE.ZA=0, and TPIDR2_EL0=0.
* A new signal frame record TPIDR2_MAGIC is added formatted as a struct
tpidr2_context to allow access to TPIDR2_EL0 from signal handlers.
@@ -241,7 +241,7 @@ prctl(PR_SME_SET_VL, unsigned long arg)
length, or calling PR_SME_SET_VL with the PR_SME_SET_VL_ONEXEC flag,
does not constitute a change to the vector length for this purpose.
- * Changing the vector length causes PSTATE.ZA and PSTATE.SM to be cleared.
+ * Changing the vector length causes PSTATE.ZA to be cleared.
Calling PR_SME_SET_VL with vl equal to the thread's current vector
length, or calling PR_SME_SET_VL with the PR_SME_SET_VL_ONEXEC flag,
does not constitute a change to the vector length for this purpose.