static inline int do_16()

in mm/alignment.c [196:311]

• 106 lines of code
• 17 McCabe index (conditional complexity)

static inline int do_16(unsigned long inst, struct pt_regs *regs)
{
	int imm, regular, load, len, addr_mode, idx_mode;
	unsigned long unaligned_addr, target_val, source_idx, target_idx,
	    shift = 0;
	switch ((inst >> 9) & 0x3F) {

	case 0x12:		/* LHI333    */
		imm = 1;
		regular = 1;
		load = 1;
		len = 2;
		addr_mode = 3;
		idx_mode = 3;
		break;
	case 0x10:		/* LWI333    */
		imm = 1;
		regular = 1;
		load = 1;
		len = 4;
		addr_mode = 3;
		idx_mode = 3;
		break;
	case 0x11:		/* LWI333.bi */
		imm = 1;
		regular = 0;
		load = 1;
		len = 4;
		addr_mode = 3;
		idx_mode = 3;
		break;
	case 0x1A:		/* LWI450    */
		imm = 0;
		regular = 1;
		load = 1;
		len = 4;
		addr_mode = 5;
		idx_mode = 4;
		break;
	case 0x16:		/* SHI333    */
		imm = 1;
		regular = 1;
		load = 0;
		len = 2;
		addr_mode = 3;
		idx_mode = 3;
		break;
	case 0x14:		/* SWI333    */
		imm = 1;
		regular = 1;
		load = 0;
		len = 4;
		addr_mode = 3;
		idx_mode = 3;
		break;
	case 0x15:		/* SWI333.bi */
		imm = 1;
		regular = 0;
		load = 0;
		len = 4;
		addr_mode = 3;
		idx_mode = 3;
		break;
	case 0x1B:		/* SWI450    */
		imm = 0;
		regular = 1;
		load = 0;
		len = 4;
		addr_mode = 5;
		idx_mode = 4;
		break;

	default:
		return -EFAULT;
	}

	if (addr_mode == 3) {
		unaligned_addr = *idx_to_addr(regs, RA3(inst));
		source_idx = RA3(inst);
	} else {
		unaligned_addr = *idx_to_addr(regs, RA5(inst));
		source_idx = RA5(inst);
	}

	if (idx_mode == 3)
		target_idx = RT3(inst);
	else
		target_idx = RT4(inst);

	if (imm)
		shift = IMM3U(inst) * len;

	if (regular)
		unaligned_addr += shift;

	if (load) {
		if (!access_ok((void *)unaligned_addr, len))
			return -EACCES;

		get_data(unaligned_addr, &target_val, len);
		*idx_to_addr(regs, target_idx) = target_val;
	} else {
		if (!access_ok((void *)unaligned_addr, len))
			return -EACCES;
		target_val = *idx_to_addr(regs, target_idx);
		set_data((void *)unaligned_addr, target_val, len);
	}

	if (!regular)
		*idx_to_addr(regs, source_idx) = unaligned_addr + shift;
	regs->ipc += 2;

	return 0;
fault:
	return -EACCES;
}