/* Trivial driver for PSIM's emulated ethernet device 'hw_ethtap'.
*
* NOTE: At the time of this writing (2009/1) 'hw_ethtap' requires
* a patched version of PSIM -- the vanilla version does not
* implement this device.
* Also, support for this device is currently only available
* on a linux host.
*
* Author/Copyright: Till Straumann <Till.Straumann@TU-Berlin.de>
*
* LICENSE
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*
*/
#include <bsp.h>
#include <rtems.h>
#include <bsp/irq.h>
#include <psim.h>
#include <libcpu/io.h>
#include <inttypes.h>
#ifndef KERNEL
#define KERNEL
#endif
#ifndef _KERNEL
#define _KERNEL
#endif
#include <rtems/rtems_bsdnet.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <stdio.h>
#define IFSIM_SLOTS 1
#define DRVNAME "if_sim"
#define IFSIM_TX_BUF_REG 1
#define IFSIM_TX_STA_REG 2
#define IFSIM_RX_BUF_REG 4
#define IFSIM_RX_STA_REG 5
#define IFSIM_RX_CNT_MSK 0xffff
#define IFSIM_RX_STA_DONE (1<<31)
#define IFSIM_RX_ERR_NOSPC (1<<20) /* buffer too small */
#define IFSIM_RX_ERR_DMA (1<<21) /* DMA error */
#define IFSIM_RX_ERR_RD (1<<23) /* file read error */
#define IFSIM_TX_STA_LST (1<<16)
#define IFSIM_TX_STA_DONE (1<<31)
#define IFSIM_IEN_REG 6
#define IFSIM_IRQ_REG 7
#define IFSIM_RX_IRQ (1<<0)
#define IFSIM_MACA0_REG 8
#define IFSIM_MACA1_REG 9
#define IFSIM_CSR_REG 10
#define IFSIM_CSR_PROM (1<<0)
/* Enable CRC generation/checking */
#define IFSIM_CSR_CRCEN (1<<1)
#define RX_BUF_ALIGNMENT 1
#define ETH_RX_OFFSET 0
/*
* Align 'p' up to a multiple of 'a' which must be
* a power of two. Result is cast to (uintptr_t)
*/
#define ALIGNTO(p,a) ((((uintptr_t)(p)) + (a) - 1) & ~((a)-1))
typedef volatile unsigned reg_t;
struct ifsim_private {
reg_t *base;
void *rbuf;
unsigned rx_cserrs;
unsigned rx_err_nospc;
unsigned rx_err_dma;
unsigned rx_err_rd;
unsigned rx_nobufs;
unsigned rx_irqs;
};
struct ifsim_softc {
struct arpcom arpcom;
struct ifsim_private pvt;
};
struct ifsim_softc theIfSims[IFSIM_SLOTS] = {{{{0}}} };
rtems_id ifsim_tid = 0;
__inline__ uint32_t
ifsim_in(struct ifsim_softc *sc, unsigned regno)
{
return in_be32( sc->pvt.base + regno );
}
__inline__ void
ifsim_out(struct ifsim_softc *sc, unsigned regno, uint32_t v)
{
out_be32(sc->pvt.base + regno, v);
}
static void *
alloc_mbuf_rx(int *psz, uintptr_t *paddr)
{
struct mbuf *m;
unsigned long l,o;
MGETHDR(m, M_DONTWAIT, MT_DATA);
if ( !m )
return 0;
MCLGET(m, M_DONTWAIT);
if ( ! (m->m_flags & M_EXT) ) {
m_freem(m);
return 0;
}
o = mtod(m, unsigned long);
l = ALIGNTO(o, RX_BUF_ALIGNMENT) - o;
/* align start of buffer */
m->m_data += l;
/* reduced length */
l = MCLBYTES - l;
m->m_len = m->m_pkthdr.len = l;
*psz = m->m_len;
*paddr = mtod(m, unsigned long);
return (void*) m;
}
static int
get_rxbuf(struct ifsim_softc *sc)
{
int sz;
uintptr_t addr;
void *nbuf;
nbuf = alloc_mbuf_rx(&sz, &addr);
if ( nbuf ) {
sc->pvt.rbuf = nbuf;
ifsim_out(sc, IFSIM_RX_BUF_REG, addr);
ifsim_out(sc, IFSIM_RX_STA_REG, sz);
return 0;
}
return -1;
}
/* set/clear promiscuous mode */
static void
ifsim_upd_promisc(struct ifsim_softc *sc)
{
uint32_t ncsr, csr;
ncsr = csr = ifsim_in(sc, IFSIM_CSR_REG);
if ( sc->arpcom.ac_if.if_flags & IFF_PROMISC )
ncsr |= IFSIM_CSR_PROM;
else
ncsr &= ~IFSIM_CSR_PROM;
if ( ncsr != csr )
ifsim_out(sc, IFSIM_CSR_REG, ncsr);
}
static void
ifsim_init(void *arg)
{
struct ifsim_softc *sc = arg;
struct ifnet *ifp = &sc->arpcom.ac_if;
if ( 0 == get_rxbuf(sc) ) {
ifsim_upd_promisc(sc);
ifp->if_flags |= IFF_RUNNING;
}
}
static void
ifsim_start(struct ifnet *ifp)
{
struct ifsim_softc *sc = ifp->if_softc;
struct mbuf *m, *mh, *m1;
while ( ifp->if_snd.ifq_head ) {
IF_DEQUEUE( &ifp->if_snd, mh );
for ( m=mh, m1 = m->m_next ; m1 ; m1 = m1->m_next ) {
ifsim_out(sc, IFSIM_TX_BUF_REG, mtod(m, uint32_t));
ifsim_out(sc, IFSIM_TX_STA_REG, m->m_len);
/* dummy-busywait; the emulated hardware DMAs our
* data away 'immediately' i.e., this loop is
* never executed
*/
while ( ! (IFSIM_TX_STA_DONE & ifsim_in(sc, IFSIM_TX_STA_REG)) )
/* Loop */;
m = m1;
}
ifsim_out(sc, IFSIM_TX_BUF_REG, mtod(m, uint32_t));
ifsim_out(sc, IFSIM_TX_STA_REG, m->m_len | IFSIM_TX_STA_LST);
/* dummy-busywait; the emulated hardware DMAs our
* data away 'immediately' i.e., this loop is
* never executed
*/
while ( ! (IFSIM_TX_STA_DONE & ifsim_in(sc, IFSIM_TX_STA_REG)) )
/* Loop */;
m_freem(mh);
}
}
static int
ifsim_ioctl(struct ifnet *ifp, ioctl_command_t cmd, caddr_t data)
{
struct ifsim_softc *sc = ifp->if_softc;
int rval = 0;
int f;
switch (cmd) {
case SIOCSIFFLAGS:
f = ifp->if_flags;
if ( f & IFF_UP ) {
if ( ! (f & IFF_RUNNING) ) {
ifsim_init(sc);
} else {
ifsim_upd_promisc(sc);
}
/* FIXME: handle other flags here */
} else {
if ( f & IFF_RUNNING ) {
printk("WARNING: bringing "DRVNAME" down not really implemented\n");
ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
}
}
break;
case SIO_RTEMS_SHOW_STATS:
printf("RX bad chksum : %u\n", sc->pvt.rx_cserrs);
printf("RX no space : %u\n", sc->pvt.rx_err_nospc);
printf("RX bad DMA : %u\n", sc->pvt.rx_err_dma);
printf("RX read errors : %u\n", sc->pvt.rx_err_rd);
printf("rx_nobufs : %u\n", sc->pvt.rx_nobufs);
printf("rx_irqs : %u\n", sc->pvt.rx_irqs);
break;
default:
rval = ether_ioctl(ifp, cmd, data);
break;
}
return rval;
}
static void ifsim_irq_on(const rtems_irq_connect_data *pd)
{
struct ifsim_softc *sc = pd->handle;
ifsim_out(sc, IFSIM_IEN_REG, IFSIM_RX_IRQ);
}
static void ifsim_irq_off(const rtems_irq_connect_data *pd)
{
struct ifsim_softc *sc = pd->handle;
ifsim_out(sc, IFSIM_IEN_REG, 0);
}
static int ifsim_irq_ison(const rtems_irq_connect_data *pd)
{
struct ifsim_softc *sc = pd->handle;
return ifsim_in(sc, IFSIM_IEN_REG) & IFSIM_RX_IRQ ? 1 : 0;
}
static void
ifsim_isr(void *arg)
{
struct ifsim_softc *sc = arg;
sc->pvt.rx_irqs++;
#ifdef IRQ_DEBUG
printk("ISR happened\n");
#endif
ifsim_out(sc, IFSIM_IEN_REG, 0);
rtems_bsdnet_event_send(ifsim_tid, (1<<(sc-theIfSims)));
}
static void
ifsim_task(void *arg)
{
struct ifsim_softc *sc;
uint32_t sta;
struct ifnet *ifp;
unsigned len;
rtems_event_set evs;
while (1) {
rtems_bsdnet_event_receive(
((1<<IFSIM_SLOTS)-1),
RTEMS_WAIT | RTEMS_EVENT_ANY,
RTEMS_NO_TIMEOUT,
&evs);
evs &= ((1<<IFSIM_SLOTS)-1);
#ifdef IRQ_DEBUG
printk("Task got evs %u\n", evs);
#endif
for ( sc = theIfSims; evs; evs>>=1, sc++ ) {
if ( ! ( evs & 1 ) )
continue;
ifp = &sc->arpcom.ac_if;
while ( ifsim_in(sc, IFSIM_IRQ_REG) & IFSIM_RX_IRQ ) {
struct mbuf *m = sc->pvt.rbuf;
sta = ifsim_in(sc, IFSIM_RX_STA_REG);
if ( (sta & IFSIM_RX_STA_DONE) ) {
if ( (ifp->if_flags & IFF_RUNNING) ) {
if ( 0 == get_rxbuf(sc) ) {
/* enqueue packet */
struct ether_header *eh;
uint32_t crc_net, crc;
int crc_len;
crc_len = (IFSIM_CSR_CRCEN & ifsim_in(sc, IFSIM_CSR_REG)) ? sizeof(crc_net) : 0;
len = (sta & IFSIM_RX_CNT_MSK) - crc_len;
eh = (struct ether_header*)(mtod(m,unsigned long) + ETH_RX_OFFSET);
m->m_len = m->m_pkthdr.len = len - sizeof(struct ether_header) - ETH_RX_OFFSET;
m->m_data += sizeof(struct ether_header) + ETH_RX_OFFSET;
m->m_pkthdr.rcvif = ifp;
#ifdef DEBUG_WO_BSDNET
{
int i;
for ( i=0; i<len + crc_len; ) {
printk("%02X ",((char*)eh)[i]);
if ( 0 == (++i & 0xf) )
fputc('\n',stdout);
}
if ( i & 0xf )
fputc('\n', stdout);
printk("*****\n");
}
#endif
if ( crc_len
&& (memcpy(&crc_net, (char*)eh + len, crc_len),
(crc = (ether_crc32_le((uint8_t *)eh, len) ^ 0xffffffff)) != crc_net) ) {
printk("CSUM: me 0x%08X, them 0x%08x\n", crc, crc_net);
sc->pvt.rx_cserrs++;
} else {
ifp->if_ipackets++;
ifp->if_ibytes += len;
#ifdef DEBUG_WO_BSDNET
m_freem(m);
#else
ether_input(ifp, eh, m);
#endif
m = 0;
}
} else {
/* throw away and reuse buffer */
sc->pvt.rx_nobufs++;
}
}
} else {
/* throw away and reuse buffer */
if ( (sta & IFSIM_RX_ERR_NOSPC) )
sc->pvt.rx_err_nospc++;
if ( (sta & IFSIM_RX_ERR_DMA) )
sc->pvt.rx_err_dma++;
if ( (sta & IFSIM_RX_ERR_RD) )
sc->pvt.rx_err_rd++;
}
if ( m ) {
/* reuse */
ifsim_out(sc, IFSIM_RX_STA_REG, m->m_pkthdr.len);
}
}
/* re-enable interrupt */
ifsim_out(sc, IFSIM_IEN_REG, IFSIM_RX_IRQ);
}
}
}
int
rtems_ifsim_attach(struct rtems_bsdnet_ifconfig *ifcfg, int attaching)
{
char *unitName;
int unit;
struct ifsim_softc *sc;
struct ifnet *ifp;
uint32_t v;
rtems_irq_connect_data ihdl;
if ( !attaching )
return -1;
unit = rtems_bsdnet_parse_driver_name(ifcfg, &unitName);
if ( unit <= 0 || unit > IFSIM_SLOTS ) {
printk(DRVNAME": Bad unit number %i; must be 1..%i\n", unit, IFSIM_SLOTS);
return 1;
}
sc = &theIfSims[unit-1];
ifp = &sc->arpcom.ac_if;
memset(&sc->pvt, 0, sizeof(sc->pvt));
sc->pvt.base = (reg_t*)ifcfg->port;
if ( 0 == sc->pvt.base )
sc->pvt.base = (reg_t*)PSIM.Ethtap;
sc->pvt.rbuf = 0;
if ( !ifsim_tid ) {
ifsim_tid = rtems_bsdnet_newproc("IFSM", 10000, ifsim_task, 0);
}
ihdl.name = ifcfg->irno;
ihdl.hdl = ifsim_isr;
ihdl.handle = sc;
ihdl.on = ifsim_irq_on;
ihdl.off = ifsim_irq_off;
ihdl.isOn = ifsim_irq_ison;
if ( ! BSP_install_rtems_irq_handler(&ihdl) ) {
printk(DRVNAME"_attach(): installing ISR failed!\n");
return -1;
}
if ( ifcfg->hardware_address ) {
memcpy(sc->arpcom.ac_enaddr, ifcfg->hardware_address, ETHER_ADDR_LEN);
} else {
v = ifsim_in(sc, IFSIM_MACA0_REG);
memcpy(sc->arpcom.ac_enaddr, &v, 4);
v = ifsim_in(sc, IFSIM_MACA1_REG);
memcpy(sc->arpcom.ac_enaddr+4, &v, 2);
}
ifp->if_softc = sc;
ifp->if_unit = unit;
ifp->if_name = unitName;
ifp->if_mtu = ifcfg->mtu ? ifcfg->mtu : ETHERMTU;
ifp->if_init = ifsim_init;
ifp->if_ioctl = ifsim_ioctl;
ifp->if_start = ifsim_start;
ifp->if_output = ether_output;
ifp->if_watchdog = 0;
ifp->if_timer = 0;
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX;
ifp->if_snd.ifq_maxlen = ifqmaxlen;
if_attach(ifp);
ether_ifattach(ifp);
return 0;
}
