static bool skx_sad_decode()

in skx_base.c [266:373]

• 97 lines of code
• 23 McCabe index (conditional complexity)

static bool skx_sad_decode(struct decoded_addr *res)
{
	struct skx_dev *d = list_first_entry(skx_edac_list, typeof(*d), list);
	u64 addr = res->addr;
	int i, idx, tgt, lchan, shift;
	u32 sad, ilv;
	u64 limit, prev_limit;
	int remote = 0;

	/* Simple sanity check for I/O space or out of range */
	if (addr >= skx_tohm || (addr >= skx_tolm && addr < BIT_ULL(32))) {
		edac_dbg(0, "Address 0x%llx out of range\n", addr);
		return false;
	}

restart:
	prev_limit = 0;
	for (i = 0; i < SKX_MAX_SAD; i++) {
		SKX_GET_SAD(d, i, sad);
		limit = SKX_SAD_LIMIT(sad);
		if (SKX_SAD_ENABLE(sad)) {
			if (addr >= prev_limit && addr <= limit)
				goto sad_found;
		}
		prev_limit = limit + 1;
	}
	edac_dbg(0, "No SAD entry for 0x%llx\n", addr);
	return false;

sad_found:
	SKX_GET_ILV(d, i, ilv);

	switch (SKX_SAD_INTERLEAVE(sad)) {
	case 0:
		idx = GET_BITFIELD(addr, 6, 8);
		break;
	case 1:
		idx = GET_BITFIELD(addr, 8, 10);
		break;
	case 2:
		idx = GET_BITFIELD(addr, 12, 14);
		break;
	case 3:
		idx = GET_BITFIELD(addr, 30, 32);
		break;
	}

	tgt = GET_BITFIELD(ilv, 4 * idx, 4 * idx + 3);

	/* If point to another node, find it and start over */
	if (SKX_ILV_REMOTE(tgt)) {
		if (remote) {
			edac_dbg(0, "Double remote!\n");
			return false;
		}
		remote = 1;
		list_for_each_entry(d, skx_edac_list, list) {
			if (d->imc[0].src_id == SKX_ILV_TARGET(tgt))
				goto restart;
		}
		edac_dbg(0, "Can't find node %d\n", SKX_ILV_TARGET(tgt));
		return false;
	}

	if (SKX_SAD_MOD3(sad) == 0) {
		lchan = SKX_ILV_TARGET(tgt);
	} else {
		switch (SKX_SAD_MOD3MODE(sad)) {
		case 0:
			shift = 6;
			break;
		case 1:
			shift = 8;
			break;
		case 2:
			shift = 12;
			break;
		default:
			edac_dbg(0, "illegal mod3mode\n");
			return false;
		}
		switch (SKX_SAD_MOD3ASMOD2(sad)) {
		case 0:
			lchan = (addr >> shift) % 3;
			break;
		case 1:
			lchan = (addr >> shift) % 2;
			break;
		case 2:
			lchan = (addr >> shift) % 2;
			lchan = (lchan << 1) | !lchan;
			break;
		case 3:
			lchan = ((addr >> shift) % 2) << 1;
			break;
		}
		lchan = (lchan << 1) | (SKX_ILV_TARGET(tgt) & 1);
	}

	res->dev = d;
	res->socket = d->imc[0].src_id;
	res->imc = GET_BITFIELD(d->mcroute, lchan * 3, lchan * 3 + 2);
	res->channel = GET_BITFIELD(d->mcroute, lchan * 2 + 18, lchan * 2 + 19);

	edac_dbg(2, "0x%llx: socket=%d imc=%d channel=%d\n",
		 res->addr, res->socket, res->imc, res->channel);
	return true;
}