• Will Deacon's avatar
    ARM: SMP: use idmap_pgd for mapping MMU enable during secondary booting · 4e8ee7de
    Will Deacon authored
    The ARM SMP booting code allocates a temporary set of page tables
    containing an identity mapping of the kernel image and provides this
    to secondary CPUs for initial booting.
    In reality, we only need to include the __turn_mmu_on function in the
    identity mapping since the rest of the kernel is executing from virtual
    addresses after this point.
    This patch adds __turn_mmu_on to the .idmap.text section, allowing the
    SMP booting code to use the idmap_pgd directly and not have to populate
    its own set of page table.
    As a result of this patch, we can make the identity_mapping_add function
    static (since it is only used within mm/idmap.c) and also remove the
    identity_mapping_del function. The identity map population is moved to
    an early initcall so that it is setup in time for secondary CPU bringup.
    Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
idmap.c 2.08 KB