[PATCH v2 0/6] RISC-V: hwprobe: Introduce which-cpus

[Andrew Jones]

This series introduces a flag for the hwprobe syscall which effectively
reverses its behavior from getting the values of keys for a set of cpus
to getting the cpus for a set of key-value pairs. The series is based on
the patch pointed out with the tag below.

Based-on: https://lore.kernel.org/all/20231010165101.14942-2-ajones@ventanamicro.com/

Changes since v1[1]:
 - Dropped copyrights when splitting hwprobe out of sys_riscv.c [Conor]
 - Improved documentation [Evan]
 - Fixed a bug where the set of cpus could get changed to the set of all
   online cpus [Evan]
 - Added check for empty set of cpus in the vdso function [Evan, drew]
 - Replaced memset with a for-loop in the vdso function because we don't
   have memset there [drew]
 - Added an r-b from Conor

Changes since the RFC[2]:
 - Split hwprobe out of sys_riscv.c into its own file [Palmer]
 - Split the which-cpus functionality out of do_riscv_hwprobe() [Palmer]
 - Rename hwprobe_key_is_map to hwprobe_key_is_bitmask [Evan]
 - Move the homogeneous_cpus logic into the vDSO function [Evan]
 - Rework logic to not need to allocate any memory
 - Honor cpu affinity in the which-cpus selftests utility
 - Picked up some r-b's

[1] https://lore.kernel.org/all/20231011135610.122850-8-ajones@ventanamicro.com/
[2] https://lore.kernel.org/all/20230921125518.175428-7-ajones@ventanamicro.com/

Andrew Jones (6):
  RISC-V: hwprobe: Clarify cpus size parameter
  RISC-V: Move the hwprobe syscall to its own file
  RISC-V: hwprobe: Introduce which-cpus flag
  RISC-V: selftests: Statically link hwprobe test
  RISC-V: selftests: Convert hwprobe test to kselftest API
  RISC-V: selftests: Add which-cpus hwprobe test

 Documentation/riscv/hwprobe.rst               |  28 +-
 arch/riscv/include/asm/hwprobe.h              |  24 ++
 arch/riscv/include/uapi/asm/hwprobe.h         |   3 +
 arch/riscv/kernel/Makefile                    |   1 +
 arch/riscv/kernel/sys_hwprobe.c               | 357 ++++++++++++++++++
 arch/riscv/kernel/sys_riscv.c                 | 267 -------------
 arch/riscv/kernel/vdso/hwprobe.c              |  86 ++++-
 .../testing/selftests/riscv/hwprobe/Makefile  |   7 +-
 .../testing/selftests/riscv/hwprobe/hwprobe.c |  64 +---
 .../testing/selftests/riscv/hwprobe/hwprobe.h |  15 +
 .../selftests/riscv/hwprobe/which-cpus.c      | 154 ++++++++
 .../selftests/riscv/vector/vstate_prctl.c     |  10 +-
 12 files changed, 676 insertions(+), 340 deletions(-)
 create mode 100644 arch/riscv/kernel/sys_hwprobe.c
 create mode 100644 tools/testing/selftests/riscv/hwprobe/hwprobe.h
 create mode 100644 tools/testing/selftests/riscv/hwprobe/which-cpus.c

-- 
2.41.0