[PATCH v5 0/8] Support Zve32[xf] and Zve64[xfd] Vector subextensions

[Andy Chiu]

The series composes of two parts. The first part Specifically,
patch 1 adds a comment at a callsite of riscv_setup_vsize to clarify how
vlenb is observed by the system. Patch 2 fixes the issue by failing the
boot process of a secondary core if vlenb mismatches.

Here is the organization of the series:
 - Patch 1, 2 provide a fix for mismatching vlen problem [1]. The
   solution is to fail secondary cores if their vlenb is not the same as
   the boot core.
 - Patch 3 is a cleanup for introducing ZVE* Vector subextensions. It
   gives the obsolete ISA parser the ability to expand ISA extensions for
   sigle letter extensions.
 - Patch 4, 5, 6 introduce Zve32x, Zve32f, Zve64x, Zve64f, Zve64d for isa
   parsing and hwprobe, and document about it.
 - Patch 7 makes has_vector() check against ZVE32X instead of V, so most
   userspace Vector supports will be available for bare ZVE32X.
 - Patch 8 updates the prctl test so that it runs on ZVE32X.

The series is tested on a QEMU and verified that booting, Vector
programs context-switch, signal, ptrace, prctl interfaces works when we
only report partial V from the ISA.

Note that the signal test was performed after applying the commit
c27fa53b858b ("riscv: Fix vector state restore in rt_sigreturn()")

This patch should be able to apply on risc-v for-next branch on top of
the commit 0a16a1728790 ("riscv: select ARCH_HAS_FAST_MULTIPLIER")

[1]: https://lore.kernel.org/all/20240228-vicinity-cornstalk-4b8eb5fe5730@spud/T/#u

Changes in v5:
 - Rebase on top of for-next
 - Update comments (1, 7)
 - Reorder the documentation patch to the front of patches that it
   documents about. (5->4)
 - Include ZVE64D to the list, which single letter V implies (6)
 - Remove ZVE32F_IMPLY_LIST (5)
 - Change the semantic of has_vector() thus rewrite patch 7
 - Remove the patch that fixes integer promotion as it is merged else
   place (8)
 - Link to v4: https://lore.kernel.org/r/20240412-zve-detection-v4-0-e0c45bb6b253@sifive.com

Changes in v4:
 - Add a patch to trigger prctl test on ZVE32X (9)
 - Add a patch to fix integer promotion bug in hwprobe (8)
 - Fix a build fail on !CONFIG_RISCV_ISA_V (7)
 - Add more comment in the assembly code change (2)
 - Link to v3: https://lore.kernel.org/r/20240318-zve-detection-v3-0-e12d42107fa8@sifive.com

Changelog v3:
 - Include correct maintainers and mailing list into CC.
 - Cleanup isa string parser code (3)
 - Adjust extensions order and name (4, 5)
 - Refine commit message (6)

Changelog v2:
 - Update comments and commit messages (1, 2, 7)
 - Refine isa_exts[] lists for zve extensions (4)
 - Add a patch for dt-binding (5)
 - Make ZVE* extensions depend on has_vector(ZVE32X) (6, 7)

---
---
Andy Chiu (8):
      riscv: vector: add a comment when calling riscv_setup_vsize()
      riscv: smp: fail booting up smp if inconsistent vlen is detected
      riscv: cpufeature: call match_isa_ext() for single-letter extensions
      dt-bindings: riscv: add Zve32[xf] Zve64[xfd] ISA extension description
      riscv: cpufeature: add zve32[xf] and zve64[xfd] isa detection
      riscv: hwprobe: add zve Vector subextensions into hwprobe interface
      riscv: vector: adjust minimum Vector requirement to ZVE32X
      selftest: run vector prctl test for ZVE32X

 Documentation/arch/riscv/hwprobe.rst               | 15 ++++++
 .../devicetree/bindings/riscv/extensions.yaml      | 30 +++++++++++
 arch/riscv/include/asm/hwcap.h                     |  5 ++
 arch/riscv/include/asm/vector.h                    | 10 ++--
 arch/riscv/include/uapi/asm/hwprobe.h              |  5 ++
 arch/riscv/kernel/cpufeature.c                     | 60 +++++++++++++++++++---
 arch/riscv/kernel/head.S                           | 19 ++++---
 arch/riscv/kernel/smpboot.c                        | 14 +++--
 arch/riscv/kernel/sys_hwprobe.c                    | 11 +++-
 arch/riscv/kernel/vector.c                         |  5 +-
 arch/riscv/lib/uaccess.S                           |  2 +-
 .../testing/selftests/riscv/vector/vstate_prctl.c  |  6 +--
 12 files changed, 151 insertions(+), 31 deletions(-)
---
base-commit: 0a16a172879012c42f55ae8c2883e17c1e4e388f
change-id: 20240318-zve-detection-50106d2da527

Best regards,
-- 
Andy Chiu <andy.chiu at sifive.com>