[PATCH v9 0/6] RISC-V: Detect and report speed of unaligned vector accesses

Jesse Taube
2024-08-20T15:27:39Z

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)

Changes in V9:
Missed a RISCV_HWPROBE_VECTOR_MISALIGNED...

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