• Bharat Bhushan's avatar
    KVM: PPC: Added one_reg interface for timer registers · 78accda4
    Bharat Bhushan authored
    If userspace wants to change some specific bits of TSR
    (timer status register) then it uses GET/SET_SREGS ioctl interface.
    So the steps will be:
          i)   user-space will make get ioctl,
          ii)  change TSR in userspace
          iii) then make set ioctl.
    It can happen that TSR gets changed by kernel after step i) and
    before step iii).
    To avoid this we have added below one_reg ioctls for oring and clearing
    specific bits in TSR. This patch adds one registerface for:
         1) setting specific bit in TSR (timer status register)
         2) clearing specific bit in TSR (timer status register)
         3) setting/getting the TCR register. There are cases where we want to only
            change TCR and not TSR. Although we can uses SREGS without
            KVM_SREGS_E_UPDATE_TSR flag but I think one reg is better. I am open
            if someone feels we should use SREGS only here.
         4) getting/setting TSR register
    Signed-off-by: default avatarBharat Bhushan <bharat.bhushan@freescale.com>
    Signed-off-by: default avatarAlexander Graf <agraf@suse.de>