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.
Signed-off-by: Charlie Jenkins charlie@rivosinc.com Signed-off-by: Jesse Taube jesse@rivosinc.com --- 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...
Changes in V10: - I sent on behalf of Jesse - Remove v0 from clobber args in inline asm and leave comment
--- 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 | 58 ++++++++++- 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 | 139 +++++++++++++++++++++++-- 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, 474 insertions(+), 38 deletions(-) --- base-commit: 98f7e32f20d28ec452afb208f9cffc08448a2652 change-id: 20240920-jesse_unaligned_vector-7083fd28659c