• Gautham R. Shenoy's avatar
    powerpc/powernv: Fix restore of SPRs upon wake up from hypervisor state loss · bd00a240
    Gautham R. Shenoy authored
    pnv_wakeup_tb_loss() currently expects cr4 to be "eq" if the CPU is
    waking up from a complete hypervisor state loss. Hence, it currently
    restores the SPR contents only if cr4 is "eq".
    
    However, after commit bcef83a0 ("powerpc/powernv: Add platform
    support for stop instruction"), on ISA v3.0 CPUs, the function
    pnv_restore_hyp_resource() sets cr4 to contain the result of the
    comparison between the state the CPU has woken up from and the first
    deep stop state before calling pnv_wakeup_tb_loss().
    
    Thus if the CPU woke up from a state that is deeper than the first
    deep stop state, cr4 will have "gt" set and hence, pnv_wakeup_tb_loss()
    will fail to restore the SPRs on waking up from such a state.
    
    Fix the code in pnv_wakeup_tb_loss() to restore the SPR states when cr4
    is "eq" or "gt".
    
    Fixes: bcef83a0
    
     ("powerpc/powernv: Add platform support for stop instruction")
    Signed-off-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
    Reviewed-by: default avatarShreyas B. Prabhu <shreyasbp@gmail.com>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    bd00a240
idle_book3s.S 15.3 KB