527  * In those cases the variable that stores the accumulative sum has to be bigger too.
528  * Once the sum is computed a final step folds the sum to a 16-bit word (adding carry if any).
532 	uint64_t sum;  in calc_chksum()  local
538 	/* Sum in is in host endianness, working order endianness is both dependent on endianness  in calc_chksum()
542 		sum = BSWAP_16(sum_in);  in calc_chksum()
544 		sum = sum_in;  in calc_chksum()
549 		sum += offset_based_swap8(data);  in calc_chksum()
555 		sum = sum + *((uint16_t *)data);  in calc_chksum()
569 		sum += sum_a + sum_b;  in calc_chksum()
573 		sum = sum + p[i++];  in calc_chksum()
578 		sum = sum + *((uint16_t *)data);  in calc_chksum()
582 		sum += offset_based_swap8(data);  in calc_chksum()
585 	/* Fold sum into 16-bit word. */  in calc_chksum()
586 	while (sum >> 16) {  in calc_chksum()
587 		sum = (sum & 0xffff) + (sum >> 16);  in calc_chksum()
590 	/* Sum in is in host endianness, working order endianness is both dependent on endianness  in calc_chksum()
594 		return BSWAP_16((uint16_t)sum);  in calc_chksum()
596 		return sum;  in calc_chksum()
600 static inline uint16_t pkt_calc_chksum(struct net_pkt *pkt, uint16_t sum)  in pkt_calc_chksum()  argument
606 		return sum;  in pkt_calc_chksum()
612 		sum = calc_chksum(sum, cur->pos, len);  in pkt_calc_chksum()
622 			sum += *cur->pos;  in pkt_calc_chksum()
623 			if (sum < *cur->pos) {  in pkt_calc_chksum()
624 				sum++;  in pkt_calc_chksum()
634 	return sum;  in pkt_calc_chksum()
641 	uint16_t sum = 0U;  in net_calc_chksum()  local
649 			sum = net_pkt_get_len(pkt) -  in net_calc_chksum()
656 		sum =  net_pkt_get_len(pkt) -  in net_calc_chksum()
672 	sum = calc_chksum(sum, pkt->cursor.pos, len);  in net_calc_chksum()
675 	sum = pkt_calc_chksum(pkt, sum);  in net_calc_chksum()
677 	sum = (sum == 0U) ? 0xffff : htons(sum);  in net_calc_chksum()
683 	return ~sum;  in net_calc_chksum()
690 	uint16_t sum;  in net_calc_chksum_ipv4()  local
692 	sum = calc_chksum(0, pkt->buffer->data,  in net_calc_chksum_ipv4()
696 	sum = (sum == 0U) ? 0xffff : htons(sum);  in net_calc_chksum_ipv4()
698 	return ~sum;  in net_calc_chksum_ipv4()