40 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
426 				  unsigned int headroom)  in mergeable_len_to_ctx()  argument
428 	return (void *)(unsigned long)((headroom << MRG_CTX_HEADER_SHIFT) | truesize);  in mergeable_len_to_ctx()
447 				   unsigned int headroom)  in page_to_skb()  argument
465 	/* If headroom is not 0, there is an offset between the beginning of the  in page_to_skb()
469 	 * Buffers with headroom use PAGE_SIZE as alloc size, see  in page_to_skb()
472 	truesize = headroom ? PAGE_SIZE : truesize;  in page_to_skb()
473 	tailroom = truesize - headroom;  in page_to_skb()
474 	buf = p - headroom;  in page_to_skb()
571 	if (unlikely(xdpf->headroom < vi->hdr_len))  in __virtnet_xdp_xmit_one()
574 	/* Make room for virtqueue hdr (also change xdpf->headroom?) */  in __virtnet_xdp_xmit_one()
709  * 2) Headroom space is insufficient.
713  * with large buffers with sufficient headroom - so it should affect
718  * have enough headroom.
762 	/* Headroom does not contribute to packet length */  in xdp_linearize_page()
782 	unsigned int headroom = vi->hdr_len + header_offset;  in receive_small()  local
783 	unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +  in receive_small()
825 			headroom = vi->hdr_len + header_offset;  in receive_small()
826 			buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +  in receive_small()
892 	skb_reserve(skb, headroom - delta);  in receive_small()
953 	unsigned int headroom = mergeable_ctx_to_headroom(ctx);  in receive_mergeable()  local
989 		/* Buffers with headroom use PAGE_SIZE as alloc size,  in receive_mergeable()
992 		frame_sz = headroom ? PAGE_SIZE : truesize;  in receive_mergeable()
995 		 * or headroom is not enough because of the buffer  in receive_mergeable()
1001 			     headroom < virtnet_get_headroom(vi))) {  in receive_mergeable()
1016 		/* Allow consuming headroom but reserve enough space to push  in receive_mergeable()
1044 			/* recalculate headroom if xdp.data or xdp_data_meta  in receive_mergeable()
1048 			 * that offset is equal to the headroom (when buf is  in receive_mergeable()
1054 			 * headroom size has changed and so has the offset, we  in receive_mergeable()
1056 			 * vnet hdr size, to calculate the new headroom and use  in receive_mergeable()
1059 			headroom = xdp.data - xdp.data_hard_start - metasize;  in receive_mergeable()
1068 						       headroom);  in receive_mergeable()
1123 			       metasize, headroom);  in receive_mergeable()
1300  * same size, except for the headroom. For this reason we do
1302  * to store the headroom as the context ignoring the truesize.
1400 	unsigned int headroom = virtnet_get_headroom(vi);  in add_recvbuf_mergeable()  local
1401 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;  in add_recvbuf_mergeable()
1402 	unsigned int room = SKB_DATA_ALIGN(headroom + tailroom);  in add_recvbuf_mergeable()
1417 	buf += headroom; /* advance address leaving hole at front of pkt */  in add_recvbuf_mergeable()
1431 	ctx = mergeable_len_to_ctx(len, headroom);  in add_recvbuf_mergeable()
3598 	unsigned int headroom = virtnet_get_headroom(vi);  in mergeable_rx_buffer_size_show()  local
3599 	unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0;  in mergeable_rx_buffer_size_show()
3606 				       SKB_DATA_ALIGN(headroom + tailroom)));  in mergeable_rx_buffer_size_show()