• Evan Green's avatar
    RISC-V: Add hwprobe vDSO function and data · aa5af0aa
    Evan Green authored
    Add a vDSO function __vdso_riscv_hwprobe, which can sit in front of the
    riscv_hwprobe syscall and answer common queries. We stash a copy of
    static answers for the "all CPUs" case in the vDSO data page. This data
    is private to the vDSO, so we can decide later to change what's stored
    there or under what conditions we defer to the syscall. Currently all
    data can be discovered at boot, so the vDSO function answers all queries
    when the cpumask is set to the "all CPUs" hint.
    
    There's also a boolean in the data that lets the vDSO function know that
    all CPUs are the same. In that case, the vDSO will also answer queries
    for arbitrary CPU masks in addition to the "all CPUs" hint.
    Signed-off-by: default avatarEvan Green <evan@rivosinc.com>
    Link: https://lore.kernel.org/r/20230407231103.2622178-7-evan@rivosinc.comSigned-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
    aa5af0aa
gettimeofday.h 2.34 KB