[PATCH v4 00/21] arm64/sme: Support SME 2 and SME 2.1

[Mark Brown]

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.  There
will be collisions with "arm64/signal: Signal handling cleanups" if that
is applied but again not super substantial.

v4:
 - Rebase onto v6.2-rc3.
 - Add SME2 value to ID_AA64PFR1_EL1.SME and move cpufeature to key off
   it.
 - Fix cut'n'paste errors and missing capability in hwcap table.
 - Fix bitrot in za-test program.
 - Typo and cut'n'paste fixes.
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).

To: Catalin Marinas <catalin.marinas at arm.com>
To: Will Deacon <will at kernel.org>
To: Oleg Nesterov <oleg at redhat.com>
To: Marc Zyngier <maz at kernel.org>
To: James Morse <james.morse at arm.com>
To: Alexandru Elisei <alexandru.elisei at arm.com>
To: Suzuki K Poulose <suzuki.poulose at arm.com>
To: Oliver Upton <oliver.upton at linux.dev>
Cc: Alan Hayward <alan.hayward at arm.com>
Cc: Luis Machado <luis.machado at arm.com>,
Cc: Szabolcs Nagy <szabolcs.nagy at arm.com>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
Cc: kvmarm at lists.linux.dev
To: Shuah Khan <shuah at kernel.org>
Cc: linux-kselftest at vger.kernel.org

---
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                    |  30 +-
 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                     |  28 ++
 arch/arm64/kernel/cpuinfo.c                        |   6 +
 arch/arm64/kernel/entry-fpsimd.S                   |  30 +-
 arch/arm64/kernel/fpsimd.c                         |  47 ++-
 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/kvm/fpsimd.c                            |   2 +-
 arch/arm64/tools/cpucaps                           |   1 +
 arch/arm64/tools/sysreg                            |  27 +-
 include/uapi/linux/elf.h                           |   1 +
 tools/testing/selftests/arm64/abi/hwcap.c          | 115 +++++++
 .../testing/selftests/arm64/abi/syscall-abi-asm.S  |  43 ++-
 tools/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         | 317 ++++++++++++++++++
 tools/testing/selftests/arm64/signal/.gitignore    |   1 +
 .../testing/selftests/arm64/signal/test_signals.h  |   2 +
 .../selftests/arm64/signal/test_signals_utils.c    |   3 +
 .../selftests/arm64/signal/testcases/testcases.c   |  36 ++
 .../selftests/arm64/signal/testcases/testcases.h   |   1 +
 .../selftests/arm64/signal/testcases/zt_no_regs.c  |  51 +++
 .../selftests/arm64/signal/testcases/zt_regs.c     |  85 +++++
 40 files changed, 1558 insertions(+), 72 deletions(-)
---
base-commit: b7bfaa761d760e72a969d116517eaa12e404c262
change-id: 20221208-arm64-sme2-363c27227a32

Best regards,
-- 
Mark Brown <broonie at kernel.org>