Document key for reporting the speed of unaligned vector accesses. The descriptions are the same as the scalar equivalent values. Signed-off-by: Jesse Taube <jesse@xxxxxxxxxxxx> Reviewed-by: Charlie Jenkins <charlie@xxxxxxxxxxxx> --- V1 -> V2: - New patch V2 -> V3: - Specify access width V3 -> V4: - Clarify we're talking about byte accesses using vector registers - Spell out _VECTOR_ in macros V4 -> V5: - No changes V5 -> V6: - No changes V6 -> V7: - No changes V7 -> V8: - Rebase onto fixes - s/RISCV_HWPROBE_VECTOR_MISALIGNED/RISCV_HWPROBE_MISALIGNED_VECTOR/g V8 -> V9: - No changes --- Documentation/arch/riscv/hwprobe.rst | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst index 85b709257918..ea4e0b9c73e7 100644 --- a/Documentation/arch/riscv/hwprobe.rst +++ b/Documentation/arch/riscv/hwprobe.rst @@ -274,3 +274,19 @@ The following keys are defined: represent the highest userspace virtual address usable. * :c:macro:`RISCV_HWPROBE_KEY_TIME_CSR_FREQ`: Frequency (in Hz) of `time CSR`. + +* :c:macro:`RISCV_HWPROBE_KEY_MISALIGNED_VECTOR_PERF`: An enum value describing the + performance of misaligned vector accesses on the selected set of processors. + + * :c:macro:`RISCV_HWPROBE_MISALIGNED_VECTOR_UNKNOWN`: The performance of misaligned + vector accesses is unknown. + + * :c:macro:`RISCV_HWPROBE_MISALIGNED_VECTOR_SLOW`: 32-bit misaligned accesses using vector + registers are slower than the equivalent quantity of byte accesses via vector registers. + Misaligned accesses may be supported directly in hardware, or trapped and emulated by software. + + * :c:macro:`RISCV_HWPROBE_MISALIGNED_VECTOR_FAST`: 32-bit misaligned accesses using vector + registers are faster than the equivalent quantity of byte accesses via vector registers. + + * :c:macro:`RISCV_HWPROBE_MISALIGNED_VECTOR_UNSUPPORTED`: Misaligned vector accesses are + not supported at all and will generate a misaligned address fault. -- 2.45.2
