101 	unsigned head;  in add_inbuf()  local
111 	head = (ring_size - 1) & (guest.avail_idx++);  in add_inbuf()
113 	head = guest.free_head;  in add_inbuf()
118 	desc[head].flags = VRING_DESC_F_NEXT;  in add_inbuf()
119 	desc[head].addr = (unsigned long)(void *)buf;  in add_inbuf()
120 	desc[head].len = len;  in add_inbuf()
125 	desc[head].flags &= ~VRING_DESC_F_NEXT;  in add_inbuf()
127 	guest.free_head = desc[head].next;  in add_inbuf()
130 	data[head].data = datap;  in add_inbuf()
137 		(head | (avail & ~(ring_size - 1))) ^ 0x8000;  in add_inbuf()
143 	ring.avail->ring[avail] = head;  in add_inbuf()
154 	unsigned head;  in get_buf()  local
159 	head = (ring_size - 1) & guest.last_used_idx;  in get_buf()
160 	index = ring.used->ring[head].id;  in get_buf()
172 	head = (ring_size - 1) & guest.last_used_idx;  in get_buf()
173 	index = head;  in get_buf()
175 	head = (ring_size - 1) & guest.last_used_idx;  in get_buf()
176 	index = ring.used->ring[head].id;  in get_buf()
183 	*lenp = ring.used->ring[head].len;  in get_buf()
201 	unsigned short head = last_used_idx & (ring_size - 1);  in used_empty()  local
202 	unsigned index = ring.used->ring[head].id;  in used_empty()
260 	unsigned head = host.used_idx;  in avail_empty()  local
262 	unsigned index = ring.avail->ring[head & (ring_size - 1)];  in avail_empty()
264 	return ((index ^ head ^ 0x8000) & ~(ring_size - 1));  in avail_empty()
266 	return head == ring.avail->idx;  in avail_empty()
274 	unsigned head;  in use_buf()  local
277 	head = ring.avail->ring[used_idx & (ring_size - 1)];  in use_buf()
278 	if ((used_idx ^ head ^ 0x8000) & ~(ring_size - 1))  in use_buf()
284 	desc = &ring.desc[head & (ring_size - 1)];  in use_buf()
294 	head = used_idx;  in use_buf()
296 	head = ring.avail->ring[used_idx];  in use_buf()
298 	desc = &ring.desc[head];  in use_buf()
308 	ring.used->ring[used_idx].id = head;  in use_buf()