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btop should really be btoc (round up vs. down)
[unix-history] / usr / src / sys / vax / if / if_en.c
/* if_en.c 4.33 82/02/05 */
#include "en.h"
/*
* Xerox prototype (3 Mb) Ethernet interface driver.
*/
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/mbuf.h"
#include "../h/pte.h"
#include "../h/buf.h"
#include "../h/protosw.h"
#include "../h/socket.h"
#include "../h/ubareg.h"
#include "../h/ubavar.h"
#include "../h/enreg.h"
#include "../h/cpu.h"
#include "../h/mtpr.h"
#include "../h/vmmac.h"
#include "../net/in.h"
#include "../net/in_systm.h"
#include "../net/if.h"
#include "../net/if_en.h"
#include "../net/if_uba.h"
#include "../net/ip.h"
#include "../net/ip_var.h"
#define ENMTU (1024+512)
int enprobe(), enattach(), enrint(), enxint(), encollide();
struct uba_device *eninfo[NEN];
u_short enstd[] = { 0 };
struct uba_driver endriver =
{ enprobe, 0, enattach, 0, enstd, "en", eninfo };
#define ENUNIT(x) minor(x)
int eninit(),enoutput(),enreset();
/*
* Ethernet software status per interface.
*
* Each interface is referenced by a network interface structure,
* es_if, which the routing code uses to locate the interface.
* This structure contains the output queue for the interface, its address, ...
* We also have, for each interface, a UBA interface structure, which
* contains information about the UNIBUS resources held by the interface:
* map registers, buffered data paths, etc. Information is cached in this
* structure for use by the if_uba.c routines in running the interface
* efficiently.
*/
struct en_softc {
struct ifnet es_if; /* network-visible interface */
struct ifuba es_ifuba; /* UNIBUS resources */
short es_delay; /* current output delay */
short es_mask; /* mask for current output delay */
u_char es_lastx; /* host last transmitted to */
short es_oactive; /* is output active? */
short es_olen; /* length of last output */
} en_softc[NEN];
/*
* Do output DMA to determine interface presence and
* interrupt vector. DMA is too short to disturb other hosts.
*/
enprobe(reg)
caddr_t reg;
{
register int br, cvec; /* r11, r10 value-result */
register struct endevice *addr = (struct endevice *)reg;
COUNT(ENPROBE);
#ifdef lint
br = 0; cvec = br; br = cvec;
enrint(0); enxint(0); encollide(0);
#endif
addr->en_istat = 0;
addr->en_owc = -1;
addr->en_oba = 0;
addr->en_ostat = EN_IEN|EN_GO;
DELAY(100000);
addr->en_ostat = 0;
return (1);
}
/*
* Interface exists: make available by filling in network interface
* record. System will initialize the interface when it is ready
* to accept packets.
*/
enattach(ui)
struct uba_device *ui;
{
register struct en_softc *es = &en_softc[ui->ui_unit];
COUNT(ENATTACH);
es->es_if.if_unit = ui->ui_unit;
es->es_if.if_name = "en";
es->es_if.if_mtu = ENMTU;
es->es_if.if_net = ui->ui_flags;
es->es_if.if_host[0] =
(~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff;
#ifdef ENKLUDGE
if (es->es_if.if_net == 10) {
es->es_if.if_host[0] <<= 16;
es->es_if.if_host[0] |= 0x4e;
}
#endif
es->es_if.if_addr =
if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]);
es->es_if.if_init = eninit;
es->es_if.if_output = enoutput;
es->es_if.if_ubareset = enreset;
es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16;
if_attach(&es->es_if);
}
/*
* Reset of interface after UNIBUS reset.
* If interface is on specified uba, reset its state.
*/
enreset(unit, uban)
int unit, uban;
{
register struct uba_device *ui;
COUNT(ENRESET);
if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 ||
ui->ui_ubanum != uban)
return;
printf(" en%d", unit);
eninit(unit);
}
/*
* Initialization of interface; clear recorded pending
* operations, and reinitialize UNIBUS usage.
*/
eninit(unit)
int unit;
{
register struct en_softc *es = &en_softc[unit];
register struct uba_device *ui = eninfo[unit];
register struct endevice *addr;
int s;
if (if_ubainit(&es->es_ifuba, ui->ui_ubanum,
sizeof (struct en_header), (int)btoc(ENMTU)) == 0) {
printf("en%d: can't initialize\n", unit);
return;
}
addr = (struct endevice *)ui->ui_addr;
addr->en_istat = addr->en_ostat = 0;
/*
* Hang a receive and start any
* pending writes by faking a transmit complete.
*/
s = splimp();
addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
addr->en_istat = EN_IEN|EN_GO;
es->es_oactive = 1;
enxint(unit);
splx(s);
}
int enlastdel = 25;
/*
* Start or restart output on interface.
* If interface is already active, then this is a retransmit
* after a collision, and just restuff registers and delay.
* If interface is not already active, get another datagram
* to send off of the interface queue, and map it to the interface
* before starting the output.
*/
enstart(dev)
dev_t dev;
{
int unit = ENUNIT(dev);
struct uba_device *ui = eninfo[unit];
register struct en_softc *es = &en_softc[unit];
register struct endevice *addr;
struct mbuf *m;
int dest;
COUNT(ENSTART);
if (es->es_oactive)
goto restart;
/*
* Not already active: dequeue another request
* and map it to the UNIBUS. If no more requests,
* just return.
*/
IF_DEQUEUE(&es->es_if.if_snd, m);
if (m == 0) {
es->es_oactive = 0;
return;
}
dest = mtod(m, struct en_header *)->en_dhost;
es->es_olen = if_wubaput(&es->es_ifuba, m);
/*
* Ethernet cannot take back-to-back packets (no
* buffering in interface. To avoid overrunning
* receiver, enforce a small delay (about 1ms) in interface
* on successive packets sent to same host.
*/
if (es->es_lastx && es->es_lastx == dest)
es->es_delay = enlastdel;
else
es->es_lastx = dest;
restart:
/*
* Have request mapped to UNIBUS for transmission.
* Purge any stale data from this BDP, and start the otput.
*/
UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp);
addr = (struct endevice *)ui->ui_addr;
addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info;
addr->en_odelay = es->es_delay;
addr->en_owc = -((es->es_olen + 1) >> 1);
addr->en_ostat = EN_IEN|EN_GO;
es->es_oactive = 1;
}
/*
* Ethernet interface transmitter interrupt.
* Start another output if more data to send.
*/
enxint(unit)
int unit;
{
register struct uba_device *ui = eninfo[unit];
register struct en_softc *es = &en_softc[unit];
register struct endevice *addr;
COUNT(ENXINT);
if (es->es_oactive == 0)
return;
addr = (struct endevice *)ui->ui_addr;
es->es_if.if_opackets++;
es->es_oactive = 0;
es->es_delay = 0;
es->es_mask = ~0;
if (addr->en_ostat&EN_OERROR) {
es->es_if.if_oerrors++;
printf("en%d: output error\n", unit);
}
if (es->es_ifuba.ifu_xtofree) {
m_freem(es->es_ifuba.ifu_xtofree);
es->es_ifuba.ifu_xtofree = 0;
}
if (es->es_if.if_snd.ifq_head == 0) {
es->es_lastx = 0;
return;
}
enstart(unit);
}
/*
* Collision on ethernet interface. Do exponential
* backoff, and retransmit. If have backed off all
* the way printing warning diagnostic, and drop packet.
*/
encollide(unit)
int unit;
{
register struct en_softc *es = &en_softc[unit];
COUNT(ENCOLLIDE);
es->es_if.if_collisions++;
if (es->es_oactive == 0)
return;
/*
* Es_mask is a 16 bit number with n low zero bits, with
* n the number of backoffs. When es_mask is 0 we have
* backed off 16 times, and give up.
*/
if (es->es_mask == 0) {
printf("en%d: send error\n", unit);
enxint(unit);
return;
}
/*
* Another backoff. Restart with delay based on n low bits
* of the interval timer.
*/
es->es_mask <<= 1;
es->es_delay = mfpr(ICR) &~ es->es_mask;
enstart(unit);
}
int enprintierrors;
/*
* Ethernet interface receiver interrupt.
* If input error just drop packet.
* Otherwise purge input buffered data path and examine
* packet to determine type. If can't determine length
* from type, then have to drop packet. Othewise decapsulate
* packet based on type and pass to type specific higher-level
* input routine.
*/
enrint(unit)
int unit;
{
register struct en_softc *es = &en_softc[unit];
struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr;
register struct en_header *en;
struct mbuf *m;
int len;
register struct ifqueue *inq;
int off;
COUNT(ENRINT);
es->es_if.if_ipackets++;
/*
* Purge BDP; drop if input error indicated.
*/
UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp);
if (addr->en_istat&EN_IERROR) {
es->es_if.if_ierrors++;
if (enprintierrors)
printf("en%d: input error\n", unit);
goto setup;
}
/*
* Get pointer to ethernet header (in input buffer).
* Deal with trailer protocol: if type is PUP trailer
* get true type from first 16-bit word past data.
* Remember that type was trailer by setting off.
*/
en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr);
#define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off))))
if (en->en_type >= ENPUP_TRAIL &&
en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) {
off = (en->en_type - ENPUP_TRAIL) * 512;
if (off >= ENMTU)
goto setup; /* sanity */
en->en_type = *endataaddr(en, off, u_short *);
} else
off = 0;
/*
* Attempt to infer packet length from type;
* can't deal with packet if can't infer length.
*/
switch (en->en_type) {
#ifdef INET
case ENPUP_IPTYPE:
len = htons((u_short)endataaddr(en, off ? off+2 : 0, struct ip *)->ip_len);
if (off)
len += 2;
setipintr();
inq = &ipintrq;
break;
#endif
default:
printf("en%d: unknow pkt type 0x%x\n", en->en_type);
goto setup;
}
if (len == 0)
goto setup;
/*
* Pull packet off interface. Off is nonzero if packet
* has trailing header; if_rubaget will then force this header
* information to be at the front, but we still have to drop
* the two-byte type which is at the front of any trailer data.
*/
m = if_rubaget(&es->es_ifuba, len, off);
if (m == 0)
goto setup;
if (off) {
m->m_off += 2;
m->m_len -= 2;
}
IF_ENQUEUE(inq, m);
setup:
/*
* Reset for next packet.
*/
addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
addr->en_istat = EN_IEN|EN_GO;
}
/*
* Ethernet output routine.
* Encapsulate a packet of type family for the local net.
* Use trailer local net encapsulation if enough data in first
* packet leaves a multiple of 512 bytes of data in remainder.
*/
enoutput(ifp, m0, pf)
struct ifnet *ifp;
struct mbuf *m0;
int pf;
{
int type, dest;
register struct mbuf *m = m0;
register struct en_header *en;
int s;
switch (pf) {
#ifdef INET
case PF_INET: {
register struct ip *ip = mtod(m0, struct ip *);
int off;
#ifndef ENKLUDGE
dest = ip->ip_dst.s_addr >> 24;
#else
dest = (ip->ip_dst.s_addr >> 8) & 0xff;
#endif
off = ntohs((u_short)ip->ip_len) - m->m_len;
#ifndef ENKLUDGE
if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) {
type = ENPUP_TRAIL + (off>>9);
m->m_off -= 2;
m->m_len += 2;
*mtod(m, u_short *) = ENPUP_IPTYPE;
goto gottrailertype;
}
#endif
type = ENPUP_IPTYPE;
off = 0;
goto gottype;
}
#endif
default:
printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf);
m_freem(m0);
return (0);
}
gottrailertype:
/*
* Packet to be sent as trailer: move first packet
* (control information) to end of chain.
*/
while (m->m_next)
m = m->m_next;
m->m_next = m0;
m = m0->m_next;
m0->m_next = 0;
m0 = m;
gottype:
/*
* Add local net header. If no space in first mbuf,
* allocate another.
*/
if (m->m_off > MMAXOFF ||
MMINOFF + sizeof (struct en_header) > m->m_off) {
m = m_get(M_DONTWAIT);
if (m == 0) {
m_freem(m0);
return (0);
}
m->m_next = m0;
m->m_off = MMINOFF;
m->m_len = sizeof (struct en_header);
} else {
m->m_off -= sizeof (struct en_header);
m->m_len += sizeof (struct en_header);
}
en = mtod(m, struct en_header *);
en->en_shost = ifp->if_host[0];
en->en_dhost = dest;
en->en_type = type;
/*
* Queue message on interface, and start output if interface
* not yet active.
*/
s = splimp();
IF_ENQUEUE(&ifp->if_snd, m);
if (en_softc[ifp->if_unit].es_oactive == 0)
enstart(ifp->if_unit);
splx(s);
return (1);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.