more cleanups, fields in ucb.h

[unix-history] / usr / src / sys / kern / uipc_mbuf.c

/* uipc_mbuf.c 1.7 81/11/04 */

#include "../h/param.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/proc.h"
#include "../h/pte.h"
#include "../h/cmap.h"
#include "../h/map.h"
#include "../h/mbuf.h"
#include "../inet/inet.h"
#include "../inet/inet_systm.h"
#include "../inet/ip.h"
#include "../inet/tcp.h"
#include "../h/vm.h"

m_reserve(mbufs)
       int mbufs;
{

       if (mbstat.m_lowat + mbufs > NNETPAGES * NMBPG - 32) 
               return (0);
       mbstat.m_lowat += mbufs;
       mbstat.m_hiwat = 2 * mbstat.m_lowat;
}

m_release(mbufs)
       int mbufs;
{

       mbstat.m_lowat -= mbufs;
       mbstat.m_hiwat = 2 * mbstat.m_lowat;
}

struct mbuf *
m_get(canwait)
       int canwait;
{
       register struct mbuf *m;

COUNT(M_GET);
       MGET(m, canwait);
       return (m);
}

struct mbuf *
m_free(m)
       struct mbuf *m;
{
       register struct mbuf *n;

COUNT(M_FREE);
       MFREE(m, n);
       return (n);
}

struct mbuf *
m_more(type)
       int type;
{
       int s;
       register struct mbuf *m;

COUNT(M_MORE);
       if (!m_expand()) {
               netstat.m_drops++;
               return (NULL);
       }
#define m_more(x) ((struct mbuf *)panic("m_more"))
       MGET(m, 0);
       return (m);
}

m_freem(m)
       register struct mbuf *m;
{
       register struct mbuf *n;
       register int s, cnt;

COUNT(M_FREEM);
       if (m == NULL)
               return (0);
       cnt = 0;
       s = splimp();
       do {
               if (m->m_off > MMAXOFF)
                       cnt += NMBPG;
               cnt++;
               MFREE(m, n);
       } while (m = n);
       splx(s);
       return (cnt);
}

mbufinit()
{
       register struct mbuf *m;
       register i;

COUNT(MBUFINIT);
       m = (struct mbuf *)&netutl[0];  /* ->start of buffer virt mem */
       vmemall(&Netmap[0], 2, proc, CSYS);
       vmaccess(&Netmap[0], m, 2);
       for (i=0; i < NMBPG; i++) {
               m->m_off = 0;
               m_free(m);
               m++;
       }
       pg_alloc(3);
       mbstat.m_pages = 4;
       mbstat.m_bufs = 32;
       mbstat.m_lowat = 16;
       mbstat.m_hiwat = 32;
       { int i,j,k,n;
       n = 32;
       k = n << 1;
       if ((i = rmalloc(netmap, n)) == 0)
               return (0);
       j = i<<1;
       m = pftom(i);
       /* should use vmemall sometimes */
       if (memall(&Netmap[j], k, proc, CSYS) == 0) {
               printf("botch\n");
               return;
       }
       vmaccess(&Netmap[j], (caddr_t)m, k);
       for (j=0; j < n; j++) {
               m->m_off = 0;
               m->m_next = mpfree;
               mpfree = m;
               m += NMBPG;
               nmpfree++;
       }
       }
}

pg_alloc(n)
       register int n;
{
       register i, j, k;
       register struct mbuf *m;
       int bufs, s;

COUNT(PG_ALLOC);
       k = n << 1;
       if ((i = rmalloc(netmap, n)) == 0)
               return (0);
       j = i<<1;
       m = pftom(i);
       /* should use vmemall sometimes */
       if (memall(&Netmap[j], k, proc, CSYS) == 0)
               return (0);
       vmaccess(&Netmap[j], (caddr_t)m, k);
       bufs = n << 3;
       s = splimp();
       for (j=0; j < bufs; j++) {
               m->m_off = 0;
               m_free(m);
               m++;
       }
       splx(s);
       mbstat.m_pages += n;
       return (1);
}

m_expand()
{
       register i;
       register struct mbuf *m, *n;
       int need, needp, needs;

COUNT(M_EXPAND);
       needs = need = mbstat.m_hiwat - mbstat.m_bufs;
       needp = need >> 3;
       if (pg_alloc(needp))
               return (1);
       for (i=0; i < needp; i++, need -= NMBPG)
               if (pg_alloc(1) == 0)
                       goto steal;
       return (need < needs);
steal:
       /* while (not enough) ask protocols to free code */
       ;
}

#ifdef notdef
m_relse()
{

COUNT(M_RELSE);
}
#endif

m_cat(m, n)
       register struct mbuf *m, *n;
{

       while (m->m_next)
               m = m->m_next;
       while (n)
               if (m->m_off + m->m_len + n->m_len <= MMAXOFF) {
                       bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, n->m_len);
                       m->m_len += n->m_len;
                       n = m_free(n);
               } else {
                       m->m_next = n;
                       m = n;
                       n = m->m_next;
               }
}

m_adj(mp, len)
       struct mbuf *mp;
       register len;
{
       register struct mbuf *m, *n;

/*
       for (m = mp; m; m = m->m_next) {
               printf("a %x %d\n", m, m->m_len);
       }
*/
COUNT(M_ADJ);
       if ((m = mp) == NULL)
               return;
       if (len >= 0) {                 /* adjust from top of msg chain */
               while (m != NULL && len > 0) {
                       if (m->m_len <= len) {          /* free this mbuf */
                               len -= m->m_len;
                               m->m_len = 0;
                               m = m->m_next;
                       } else {                        /* adjust mbuf */
                               m->m_len -= len;
                               m->m_off += len;
                               break;
                       }
               }

       } else {                        /* adjust from bottom of msg chain */
               len = -len;
               while (len > 0 && m->m_len != 0) {
                       /* find end of chain */
                       while (m != NULL && m->m_len != 0) {
                               n = m;
                               m = m->m_next;
                       }
                       if (n->m_len <= len) {          /* last mbuf */
                               len -= n->m_len;
                               n->m_len = 0;
                               m = mp;
                       } else {                        /* adjust length */
                               n->m_len -= len;
                               break;
                       }
               }
       }
}

/*
* convert mbuf virtual to physical addr for uballoc
*/
mtophys(m)
       register struct mbuf *m;
{
       register i;
       register unsigned long addr;
       register struct pte *pte;

COUNT(MTOPHYS);
       i = (((int)m & ~PGOFSET) - (int)netutl) >> PGSHIFT;
       pte = &Netmap[i];
       addr = (pte->pg_pfnum << PGSHIFT) | ((int)m & PGOFSET);
       return (addr);
}