• Mihai Caraman's avatar
    powerpc/booke64: Eemove mfspr srr1 duplicate in exception prolog · 79b5c8db
    Mihai Caraman authored
    Refactor exception prolog to get rid of mfspr srr1 duplicate. This was
    introduced by KVM integration, with DO_KVM macro logic expecting srr1 value
    earlier in r11.
    Reserve r11 to hold srr1's value also required at the end of the prolog and
    free up r10 to serve as spare in addition macros.
    For syscalls case this change does not add any performance penalty. For irq
    soft-disabled case the change adds a store/load of conditional register value
    to/from a paca slot. Paca slots fit in one 64-byte cache line so these
    additional operations have little impact on performance.
    Signed-off-by: default avatarMihai Caraman <mihai.caraman@freescale.com>
    Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
    79b5c8db
exceptions-64e.S 38.3 KB