rdsinit.c

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/* rdsinit.c - rdsinit */

#include <xinu.h>

struct rdscblk rdstab[Nrds];

/*------------------------------------------------------------------------
 *  rdsinit  -  Initialize the remote disk system device
 *------------------------------------------------------------------------
 */
devcall rdsinit(
    struct dentry *devptr /* Entry in device switch table   */
)
{
    struct rdscblk *rdptr; /* Ptr to device contol block    */
    struct rdbuff *bptr;   /* Ptr to buffer in memory   */
    /*   used to form linked list   */
    struct rdbuff *pptr;    /* Ptr to previous buff on list */
    struct rdbuff *buffend; /* Last address in buffer memory*/
    uint32 size;            /* Total size of memory needed  */
    /*   buffers            */

    /* Obtain address of control block */

    rdptr = &rdstab[devptr->dvminor];

    /* Set control block to unused */

    rdptr->rd_state = RD_FREE;

    /* Create the resprocess and leave it suspended.    */
    /*  Note: the process cannot be resumed because */
    /*  device initialization occurs before interrupts  */
    /*  are enabled.                    */

    rdptr->rd_comproc = create(rdsprocess, RD_STACK, RD_PRIO,
                               "rdsproc", 1, rdptr);
    if (rdptr->rd_comproc == SYSERR)
    {
        panic("Cannot create remote disk process");
    }
    rdptr->rd_comruns = FALSE;

    rdptr->rd_id[0] = NULLCH;

    /* Set initial message sequence number */

    rdptr->rd_seq = 1;

    /* Initialize request queue and cache to empty */

    rdptr->rd_rhnext = (struct rdbuff *)&rdptr->rd_rtnext;
    rdptr->rd_rhprev = (struct rdbuff *)NULL;

    rdptr->rd_rtnext = (struct rdbuff *)NULL;
    rdptr->rd_rtprev = (struct rdbuff *)&rdptr->rd_rhnext;

    rdptr->rd_chnext = (struct rdbuff *)&rdptr->rd_ctnext;
    rdptr->rd_chprev = (struct rdbuff *)NULL;

    rdptr->rd_ctnext = (struct rdbuff *)NULL;
    rdptr->rd_ctprev = (struct rdbuff *)&rdptr->rd_chnext;

    /* Allocate memory for a set of buffers (actually request   */
    /*    blocks and link them to form the initial free list    */

    size = sizeof(struct rdbuff) * RD_BUFFS;

    bptr = (struct rdbuff *)getmem(size);
    rdptr->rd_free = bptr;

    if ((int32)bptr == SYSERR)
    {
        panic("Cannot allocate memory for remote disk buffers");
    }

    pptr = (struct rdbuff *)NULL; /* To avoid a compiler warning    */
    buffend = (struct rdbuff *)((char *)bptr + size);
    while (bptr < buffend)
    { /* walk through memory */
        pptr = bptr;
        bptr = (struct rdbuff *)(sizeof(struct rdbuff) + (char *)bptr);
        pptr->rd_status = RD_INVALID; /* Buffer is empty    */
        pptr->rd_next = bptr;         /* Point to next buffer */
    }
    pptr->rd_next = (struct rdbuff *)NULL; /* Last buffer on list   */

    /* Create the request list and available buffer semaphores */

    rdptr->rd_availsem = semcreate(RD_BUFFS);
    rdptr->rd_reqsem = semcreate(0);

    /* Set the server IP address, server port, and local port */

    if (dot2ip(RD_SERVER_IP, &rdptr->rd_ser_ip) == SYSERR)
    {
        panic("invalid IP address for remote disk server");
    }

    /* Set the port numbers */

    rdptr->rd_ser_port = RD_SERVER_PORT;
    rdptr->rd_loc_port = RD_LOC_PORT + devptr->dvminor;

    /* Specify that the server port is not yet registered */

    rdptr->rd_registered = FALSE;

    return OK;
}