REG_APSIZE
vsc->regs[REG_APSIZE]);
pci_conf_write(vsc->vsc_pc, vsc->vsc_tag, vsc->regs[REG_APSIZE],
vsc->regs[REG_APSIZE]) & 0x1f;
reg = pci_conf_read(vsc->vsc_pc, vsc->vsc_tag, vsc->regs[REG_APSIZE]);
pci_conf_write(vsc->vsc_pc, vsc->vsc_tag, vsc->regs[REG_APSIZE], reg);