s390/crypto/aes_s390.c

673 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
676 	memset(gw, 0, sizeof(*gw));
677 	gw->walk_bytes_remain = len;
678 	scatterwalk_start(&gw->walk, sg);
681 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
685 	gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
686 	while (!gw->walk_bytes) {
687 		nextsg = sg_next(gw->walk.sg);
690 		scatterwalk_start(&gw->walk, nextsg);
691 		gw->walk_bytes = scatterwalk_clamp(&gw->walk,
692 						   gw->walk_bytes_remain);
694 	gw->walk_ptr = scatterwalk_map(&gw->walk);
695 	return gw->walk_bytes;
698 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
701 	gw->walk_bytes_remain -= nbytes;
702 	scatterwalk_unmap(gw->walk_ptr);
703 	scatterwalk_advance(&gw->walk, nbytes);
704 	scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
705 	gw->walk_ptr = NULL;
708 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
712 	if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
713 		gw->ptr = gw->buf;
714 		gw->nbytes = gw->buf_bytes;
718 	if (gw->walk_bytes_remain == 0) {
719 		gw->ptr = NULL;
720 		gw->nbytes = 0;
724 	if (!_gcm_sg_clamp_and_map(gw)) {
725 		gw->ptr = NULL;
726 		gw->nbytes = 0;
730 	if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
731 		gw->ptr = gw->walk_ptr;
732 		gw->nbytes = gw->walk_bytes;
737 		n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
738 		memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
739 		gw->buf_bytes += n;
740 		_gcm_sg_unmap_and_advance(gw, n);
741 		if (gw->buf_bytes >= minbytesneeded) {
742 			gw->ptr = gw->buf;
743 			gw->nbytes = gw->buf_bytes;
746 		if (!_gcm_sg_clamp_and_map(gw)) {
747 			gw->ptr = NULL;
748 			gw->nbytes = 0;
754 	return gw->nbytes;
757 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
759 	if (gw->walk_bytes_remain == 0) {
760 		gw->ptr = NULL;
761 		gw->nbytes = 0;
765 	if (!_gcm_sg_clamp_and_map(gw)) {
766 		gw->ptr = NULL;
767 		gw->nbytes = 0;
771 	if (gw->walk_bytes >= minbytesneeded) {
772 		gw->ptr = gw->walk_ptr;
773 		gw->nbytes = gw->walk_bytes;
777 	scatterwalk_unmap(gw->walk_ptr);
778 	gw->walk_ptr = NULL;
780 	gw->ptr = gw->buf;
781 	gw->nbytes = sizeof(gw->buf);
784 	return gw->nbytes;
787 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
789 	if (gw->ptr == NULL)
792 	if (gw->ptr == gw->buf) {
793 		int n = gw->buf_bytes - bytesdone;
795 			memmove(gw->buf, gw->buf + bytesdone, n);
796 			gw->buf_bytes = n;
798 			gw->buf_bytes = 0;
800 		_gcm_sg_unmap_and_advance(gw, bytesdone);
805 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
809 	if (gw->ptr == NULL)
812 	if (gw->ptr == gw->buf) {
814 			if (!_gcm_sg_clamp_and_map(gw))
816 			n = min(gw->walk_bytes, bytesdone - i);
817 			memcpy(gw->walk_ptr, gw->buf + i, n);
818 			_gcm_sg_unmap_and_advance(gw, n);
821 		_gcm_sg_unmap_and_advance(gw, bytesdone);