• James Morse's avatar
    arm64: suspend: Reconfigure PSTATE after resume from idle · d0854412
    James Morse authored
    The suspend/resume path in kernel/sleep.S, as used by cpu-idle, does not
    save/restore PSTATE. As a result of this cpufeatures that were detected
    and have bits in PSTATE get lost when we resume from idle.
    
    UAO gets set appropriately on the next context switch. PAN will be
    re-enabled next time we return from user-space, but on a preemptible
    kernel we may run work accessing user space before this point.
    
    Add code to re-enable theses two features in __cpu_suspend_exit().
    We re-use uao_thread_switch() passing current.
    Signed-off-by: default avatarJames Morse <james.morse@arm.com>
    Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    d0854412
suspend.c 3.68 KB