usr/src/sys/vax/if/if_uba.h

/*      if_uba.h        4.2     81/11/26        */

/*
 * Structure and routine definitions
 * for UNIBUS network interfaces.
 */

#define IF_NUBAMR       6
/*
 * Each interface has one of these structures giving information
 * about UNIBUS resources held by the interface.
 *
 * We hold IF_NUBAMR map registers for datagram data, starting
 * at ifr_mr.  Map register ifr_mr[-1] maps the local network header
 * ending on the page boundary.  Bdp's are reserved for read and for
 * write, given by ifr_bdp.  The prototype of the map register for
 * read and for write is saved in ifr_proto.
 *
 * When write transfers are not full pages on page boundaries we just
 * copy the data into the pages mapped on the UNIBUS and start the
 * transfer.  If a write transfer is of a (1024 byte) page on a page
 * boundary, we swap in UNIBUS pte's to reference the pages, and then
 * remap the initial pages (from ifu_wmap) when the transfer completes.
 *
 * When read transfers give whole pages of data to be input, we
 * allocate page frames from a network page list and trade them
 * with the pages already containing the data, mapping the allocated
 * pages to replace the input pages for the next UNIBUS data input.
 */
struct  ifuba {
        short   ifu_uban;                       /* uba number */
        struct  uba_regs *ifu_uba;              /* uba regs, in vm */
        struct ifrw {
                int     ifrw_info;              /* value from ubaalloc */
                short   ifrw_bdp;               /* unibus bdp */
                struct  pte *ifrw_mr;           /* base of map registers */
                int     ifrw_proto;             /* map register prototype */
                caddr_t ifrw_addr;              /* virt addr of header */
        } ifu_r, ifu_w;
        struct  pte ifu_wmap[IF_NUBAMR];        /* base pages for output */
        short   ifu_hlen;
/* ifu_xswapd is set when we have swapped write pte's to do direct output */
/* bit i of ifu_xswapd */
        short   ifu_xswapd;                     /* bit map of pages swapped */
        int     ifu_ierrors;
        int     ifu_oerrors;
        int     ifu_collisions;
};

#ifdef  KERNEL
struct  mbuf *if_rubaget();
#endif