• Paul Mackerras's avatar
    powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit · e31aa453
    Paul Mackerras authored
    Using LOAD_REG_IMMEDIATE to get the address of kernel symbols
    generates 5 instructions where LOAD_REG_ADDR can do it in one,
    and will generate R_PPC64_ADDR16_* relocations in the output when
    we get to making the kernel as a position-independent executable,
    which we'd rather not have to handle.  This changes various bits
    of assembly code to use LOAD_REG_ADDR when we need to get the
    address of a symbol, or to use suitable position-independent code
    for cases where we can't access the TOC for various reasons, or
    if we're not running at the address we were linked at.
    
    It also cleans up a few minor things; there's no reason to save and
    restore SRR0/1 around RTAS calls, __mmu_off can get the return
    address from LR more conveniently than the caller can supply it in
    R4 (and we already assume elsewhere that EA == RA if the MMU is on
    in early boot), and enable_64b_mode was using 5 instructions where
    2 would do.
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    e31aa453
ppc_asm.h 17.9 KB