REG_APSIZE
asc->regs[REG_APSIZE]) & 0xff;
asc->regs[REG_APSIZE]) & 0xfff;
asc->regs[REG_APSIZE]);
asc->regs[REG_APSIZE], reg);
reg = pci_conf_read(sc->as_pc, sc->as_tag, asc->regs[REG_APSIZE]);
pci_conf_write(sc->as_pc, sc->as_tag, asc->regs[REG_APSIZE], reg);