[v8,0/6] RISC-V: Detect and report speed of unaligned vector accesses

Message

Jesse Taube Aug. 19, 2024, 9:25 p.m. UTC

Adds support for detecting and reporting the speed of unaligned vector
accesses on RISC-V CPUs. Adds vec_misaligned_speed key to the hwprobe
adds Zicclsm to cpufeature and fixes the check for scalar unaligned
emulated all CPUs. The vec_misaligned_speed key keeps the same format
as the scalar unaligned access speed key.

This set does not emulate unaligned vector accesses on CPUs that do not
support them. Only reports if userspace can run them and speed of
unaligned vector accesses if supported.

The Zicclsm is patches are no longer related to this set.

Changes in v6:
 Added ("RISC-V: Scalar unaligned access emulated on hotplug CPUs")

Changes in V8:
 Dropped Zicclsm
 s/RISCV_HWPROBE_VECTOR_MISALIGNED/RISCV_HWPROBE_MISALIGNED_VECTOR/g
  to match RISCV_HWPROBE_MISALIGNED_SCALAR_*
 Rebased onto palmer/fixes (32d5f7add080a936e28ab4142bfeea6b06999789)

Jesse Taube (6):
  RISC-V: Check scalar unaligned access on all CPUs
  RISC-V: Scalar unaligned access emulated on hotplug CPUs
  RISC-V: Replace RISCV_MISALIGNED with RISCV_SCALAR_MISALIGNED
  RISC-V: Detect unaligned vector accesses supported
  RISC-V: Report vector unaligned access speed hwprobe
  RISC-V: hwprobe: Document unaligned vector perf key

 Documentation/arch/riscv/hwprobe.rst       |  16 +++
 arch/riscv/Kconfig                         |  57 +++++++-
 arch/riscv/include/asm/cpufeature.h        |  10 +-
 arch/riscv/include/asm/entry-common.h      |  11 --
 arch/riscv/include/asm/hwprobe.h           |   2 +-
 arch/riscv/include/asm/vector.h            |   2 +
 arch/riscv/include/uapi/asm/hwprobe.h      |   5 +
 arch/riscv/kernel/Makefile                 |   3 +-
 arch/riscv/kernel/copy-unaligned.h         |   5 +
 arch/riscv/kernel/fpu.S                    |   4 +-
 arch/riscv/kernel/sys_hwprobe.c            |  41 ++++++
 arch/riscv/kernel/traps_misaligned.c       | 131 +++++++++++++++--
 arch/riscv/kernel/unaligned_access_speed.c | 156 +++++++++++++++++++--
 arch/riscv/kernel/vec-copy-unaligned.S     |  58 ++++++++
 arch/riscv/kernel/vector.c                 |   2 +-
 15 files changed, 465 insertions(+), 38 deletions(-)
 create mode 100644 arch/riscv/kernel/vec-copy-unaligned.S

base-commit: 32d5f7add080a936e28ab4142bfeea6b06999789