extern void sun4v_data_access_exception()

in kernel/unaligned_64.c [433:568]

• 124 lines of code
• 35 McCabe index (conditional complexity)

extern void sun4v_data_access_exception(struct pt_regs *regs,
					unsigned long addr,
					unsigned long type_ctx);

int handle_ldf_stq(u32 insn, struct pt_regs *regs)
{
	unsigned long addr = compute_effective_address(regs, insn, 0);
	int freg;
	struct fpustate *f = FPUSTATE;
	int asi = decode_asi(insn, regs);
	int flag;

	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);

	save_and_clear_fpu();
	current_thread_info()->xfsr[0] &= ~0x1c000;
	if (insn & 0x200000) {
		/* STQ */
		u64 first = 0, second = 0;
		
		freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
		flag = (freg < 32) ? FPRS_DL : FPRS_DU;
		if (freg & 3) {
			current_thread_info()->xfsr[0] |= (6 << 14) /* invalid_fp_register */;
			do_fpother(regs);
			return 0;
		}
		if (current_thread_info()->fpsaved[0] & flag) {
			first = *(u64 *)&f->regs[freg];
			second = *(u64 *)&f->regs[freg+2];
		}
		if (asi < 0x80) {
			do_privact(regs);
			return 1;
		}
		switch (asi) {
		case ASI_P:
		case ASI_S: break;
		case ASI_PL:
		case ASI_SL: 
			{
				/* Need to convert endians */
				u64 tmp = __swab64p(&first);
				
				first = __swab64p(&second);
				second = tmp;
				break;
			}
		default:
			if (tlb_type == hypervisor)
				sun4v_data_access_exception(regs, addr, 0);
			else
				spitfire_data_access_exception(regs, 0, addr);
			return 1;
		}
		if (put_user (first >> 32, (u32 __user *)addr) ||
		    __put_user ((u32)first, (u32 __user *)(addr + 4)) ||
		    __put_user (second >> 32, (u32 __user *)(addr + 8)) ||
		    __put_user ((u32)second, (u32 __user *)(addr + 12))) {
			if (tlb_type == hypervisor)
				sun4v_data_access_exception(regs, addr, 0);
			else
				spitfire_data_access_exception(regs, 0, addr);
		    	return 1;
		}
	} else {
		/* LDF, LDDF, LDQF */
		u32 data[4] __attribute__ ((aligned(8)));
		int size, i;
		int err;

		if (asi < 0x80) {
			do_privact(regs);
			return 1;
		} else if (asi > ASI_SNFL) {
			if (tlb_type == hypervisor)
				sun4v_data_access_exception(regs, addr, 0);
			else
				spitfire_data_access_exception(regs, 0, addr);
			return 1;
		}
		switch (insn & 0x180000) {
		case 0x000000: size = 1; break;
		case 0x100000: size = 4; break;
		default: size = 2; break;
		}
		if (size == 1)
			freg = (insn >> 25) & 0x1f;
		else
			freg = ((insn >> 25) & 0x1e) | ((insn >> 20) & 0x20);
		flag = (freg < 32) ? FPRS_DL : FPRS_DU;

		for (i = 0; i < size; i++)
			data[i] = 0;
		
		err = get_user (data[0], (u32 __user *) addr);
		if (!err) {
			for (i = 1; i < size; i++)
				err |= __get_user (data[i], (u32 __user *)(addr + 4*i));
		}
		if (err && !(asi & 0x2 /* NF */)) {
			if (tlb_type == hypervisor)
				sun4v_data_access_exception(regs, addr, 0);
			else
				spitfire_data_access_exception(regs, 0, addr);
			return 1;
		}
		if (asi & 0x8) /* Little */ {
			u64 tmp;

			switch (size) {
			case 1: data[0] = le32_to_cpup(data + 0); break;
			default:*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 0));
				break;
			case 4: tmp = le64_to_cpup((u64 *)(data + 0));
				*(u64 *)(data + 0) = le64_to_cpup((u64 *)(data + 2));
				*(u64 *)(data + 2) = tmp;
				break;
			}
		}
		if (!(current_thread_info()->fpsaved[0] & FPRS_FEF)) {
			current_thread_info()->fpsaved[0] = FPRS_FEF;
			current_thread_info()->gsr[0] = 0;
		}
		if (!(current_thread_info()->fpsaved[0] & flag)) {
			if (freg < 32)
				memset(f->regs, 0, 32*sizeof(u32));
			else
				memset(f->regs+32, 0, 32*sizeof(u32));
		}
		memcpy(f->regs + freg, data, size * 4);
		current_thread_info()->fpsaved[0] |= flag;
	}
	advance(regs);
	return 1;
}