1 /******************************************************************************
4 * Unified network-device I/O interface for Xen guest OSes.
6 * Copyright (c) 2003-2004, Keir Fraser
9 #ifndef __XEN_PUBLIC_IO_NETIF_H__
10 #define __XEN_PUBLIC_IO_NETIF_H__
13 memory_t addr; /* 0: Machine address of packet. */
15 u16 id; /* 8: Echoed in response message. */
16 u16 size; /* 10: Packet size in bytes. */
17 } PACKED netif_tx_request_t; /* 12 bytes */
23 } PACKED netif_tx_response_t; /* 4 bytes */
26 u16 id; /* 0: Echoed in response message. */
27 } PACKED netif_rx_request_t; /* 2 bytes */
30 memory_t addr; /* 0: Machine address of packet. */
33 s16 status; /* 10: -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
34 } PACKED netif_rx_response_t; /* 12 bytes */
37 * We use a special capitalised type name because it is _essential_ that all
38 * arithmetic on indexes is done on an integer type of the correct size.
40 typedef u32 NETIF_RING_IDX;
43 * Ring indexes are 'free running'. That is, they are not stored modulo the
44 * size of the ring buffer. The following macros convert a free-running counter
45 * into a value that can directly index a ring-buffer array.
47 #define MASK_NETIF_RX_IDX(_i) ((_i)&(NETIF_RX_RING_SIZE-1))
48 #define MASK_NETIF_TX_IDX(_i) ((_i)&(NETIF_TX_RING_SIZE-1))
50 #define NETIF_TX_RING_SIZE 256
51 #define NETIF_RX_RING_SIZE 256
53 /* This structure must fit in a memory page. */
56 * Frontend places packets into ring at tx_req_prod.
57 * Frontend receives event when tx_resp_prod passes tx_event.
58 * 'req_cons' is a shadow of the backend's request consumer -- the frontend
59 * may use it to determine if all queued packets have been seen by the
62 NETIF_RING_IDX req_prod; /* 0 */
63 NETIF_RING_IDX req_cons; /* 4 */
64 NETIF_RING_IDX resp_prod; /* 8 */
65 NETIF_RING_IDX event; /* 12 */
67 netif_tx_request_t req;
68 netif_tx_response_t resp;
69 } PACKED ring[NETIF_TX_RING_SIZE];
70 } PACKED netif_tx_interface_t;
72 /* This structure must fit in a memory page. */
75 * Frontend places empty buffers into ring at rx_req_prod.
76 * Frontend receives event when rx_resp_prod passes rx_event.
78 NETIF_RING_IDX req_prod; /* 0 */
79 NETIF_RING_IDX resp_prod; /* 4 */
80 NETIF_RING_IDX event; /* 8 */
82 netif_rx_request_t req;
83 netif_rx_response_t resp;
84 } PACKED ring[NETIF_RX_RING_SIZE];
85 } PACKED netif_rx_interface_t;
87 /* Descriptor status values */
88 #define NETIF_RSP_DROPPED -2
89 #define NETIF_RSP_ERROR -1
90 #define NETIF_RSP_OKAY 0