Arm have recently released versions 2 and 2.1 of the SME extension. Among the features introduced by SME 2 is some new architectural state, the ZT0 register. This series adds support for this and all the other features of the new SME versions.

Since the architecture has been designed with the possibility of adding further ZTn registers in mind the interfaces added for ZT0 are done with this possibility in mind. As ZT0 is a simple fixed size register these interfaces are all fairly simple, the main complication is that ZT0 is only accessible when PSTATE.ZA is enabled. The memory allocation that we already do for PSTATE.ZA is extended to include space for ZT0.

Due to textual collisions especially around the addition of hwcaps this is based on the recently merged series "arm64: Support for 2022 data processing instructions" but there is no meaningful interaction.

v3: - Rebase onto merged series for the 2022 architectur extensions. - Clarifications and typo fixes in the ABI documentation. v2: - Add missing initialisation of user->zt in signal context parsing. - Change the magic for ZT signal frames to 0x5a544e01 (ZTN0).

Mark Brown (21): arm64/sme: Rename za_state to sme_state arm64: Document boot requirements for SME 2 arm64/sysreg: Update system registers for SME 2 and 2.1 arm64/sme: Document SME 2 and SME 2.1 ABI arm64/esr: Document ISS for ZT0 being disabled arm64/sme: Manually encode ZT0 load and store instructions arm64/sme: Enable host kernel to access ZT0 arm64/sme: Add basic enumeration for SME2 arm64/sme: Provide storage for ZT0 arm64/sme: Implement context switching for ZT0 arm64/sme: Implement signal handling for ZT arm64/sme: Implement ZT0 ptrace support arm64/sme: Add hwcaps for SME 2 and 2.1 features kselftest/arm64: Add a stress test program for ZT0 kselftest/arm64: Cover ZT in the FP stress test kselftest/arm64: Enumerate SME2 in the signal test utility code kselftest/arm64: Teach the generic signal context validation about ZT kselftest/arm64: Add test coverage for ZT register signal frames kselftest/arm64: Add SME2 coverage to syscall-abi kselftest/arm64: Add coverage of the ZT ptrace regset kselftest/arm64: Add coverage of SME 2 and 2.1 hwcaps

Documentation/arm64/booting.rst | 10 + Documentation/arm64/elf_hwcaps.rst | 18 + Documentation/arm64/sme.rst | 52 ++- arch/arm64/include/asm/cpufeature.h | 6 + arch/arm64/include/asm/esr.h | 1 + arch/arm64/include/asm/fpsimd.h | 28 +- arch/arm64/include/asm/fpsimdmacros.h | 22 ++ arch/arm64/include/asm/hwcap.h | 6 + arch/arm64/include/asm/processor.h | 2 +- arch/arm64/include/uapi/asm/hwcap.h | 6 + arch/arm64/include/uapi/asm/sigcontext.h | 19 + arch/arm64/kernel/cpufeature.c | 27 ++ arch/arm64/kernel/cpuinfo.c | 6 + arch/arm64/kernel/entry-fpsimd.S | 30 +- arch/arm64/kernel/fpsimd.c | 53 ++- arch/arm64/kernel/hyp-stub.S | 6 + arch/arm64/kernel/idreg-override.c | 1 + arch/arm64/kernel/process.c | 21 +- arch/arm64/kernel/ptrace.c | 60 ++- arch/arm64/kernel/signal.c | 113 +++++- arch/arm64/tools/cpucaps | 1 + arch/arm64/tools/sysreg | 26 +- include/uapi/linux/elf.h | 1 + tools/testing/selftests/arm64/abi/hwcap.c | 115 ++++++ .../selftests/arm64/abi/syscall-abi-asm.S | 43 ++- .../testing/selftests/arm64/abi/syscall-abi.c | 40 +- tools/testing/selftests/arm64/fp/.gitignore | 2 + tools/testing/selftests/arm64/fp/Makefile | 5 + tools/testing/selftests/arm64/fp/fp-stress.c | 29 +- tools/testing/selftests/arm64/fp/sme-inst.h | 20 + tools/testing/selftests/arm64/fp/zt-ptrace.c | 365 ++++++++++++++++++ tools/testing/selftests/arm64/fp/zt-test.S | 324 ++++++++++++++++ .../testing/selftests/arm64/signal/.gitignore | 1 + .../selftests/arm64/signal/test_signals.h | 2 + .../arm64/signal/test_signals_utils.c | 3 + .../arm64/signal/testcases/testcases.c | 36 ++ .../arm64/signal/testcases/testcases.h | 1 + .../arm64/signal/testcases/zt_no_regs.c | 51 +++ .../arm64/signal/testcases/zt_regs.c | 85 ++++ 39 files changed, 1564 insertions(+), 73 deletions(-) create mode 100644 tools/testing/selftests/arm64/fp/zt-ptrace.c create mode 100644 tools/testing/selftests/arm64/fp/zt-test.S create mode 100644 tools/testing/selftests/arm64/signal/testcases/zt_no_regs.c create mode 100644 tools/testing/selftests/arm64/signal/testcases/zt_regs.c

base-commit: c5195b027d29bbaae0c9668704ab996773788d23