/* $OpenBSD: ne2000.c,v 1.7 1999/03/26 06:34:26 fgsch Exp $ */ /* $NetBSD: ne2000.c,v 1.12 1998/06/10 01:15:50 thorpej Exp $ */ /*- * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Device driver for National Semiconductor DS8390/WD83C690 based ethernet * adapters. * * Copyright (c) 1994, 1995 Charles M. Hannum. All rights reserved. * * Copyright (C) 1993, David Greenman. This software may be used, modified, * copied, distributed, and sold, in both source and binary form provided that * the above copyright and these terms are retained. Under no circumstances is * the author responsible for the proper functioning of this software, nor does * the author assume any responsibility for damages incurred with its use. */ /* * Common code shared by all NE2000-compatible Ethernet interfaces. */ #include #include #include #include #include #include #include #include #include #include #ifdef __NetBSD__ #include #else #include #include #endif #include #ifndef __BUS_SPACE_HAS_STREAM_METHODS #define bus_space_write_stream_2 bus_space_write_2 #define bus_space_write_multi_stream_2 bus_space_write_multi_2 #define bus_space_read_multi_stream_2 bus_space_read_multi_2 #endif /* __BUS_SPACE_HAS_STREAM_METHODS */ #include #include #include #include int ne2000_write_mbuf __P((struct dp8390_softc *, struct mbuf *, int)); int ne2000_ring_copy __P((struct dp8390_softc *, int, caddr_t, u_short)); void ne2000_read_hdr __P((struct dp8390_softc *, int, struct dp8390_ring *)); int ne2000_test_mem __P((struct dp8390_softc *)); void ne2000_writemem __P((bus_space_tag_t, bus_space_handle_t, bus_space_tag_t, bus_space_handle_t, u_int8_t *, int, size_t, int)); void ne2000_readmem __P((bus_space_tag_t, bus_space_handle_t, bus_space_tag_t, bus_space_handle_t, int, u_int8_t *, size_t, int)); struct cfdriver ne_cd = { NULL, "ne", DV_IFNET }; void ne2000_attach(nsc, myea, media, nmedia, defmedia) struct ne2000_softc *nsc; u_int8_t *myea; int *media, nmedia, defmedia; { struct dp8390_softc *dsc = &nsc->sc_dp8390; bus_space_tag_t nict = dsc->sc_regt; bus_space_handle_t nich = dsc->sc_regh; bus_space_tag_t asict = nsc->sc_asict; bus_space_handle_t asich = nsc->sc_asich; u_int8_t romdata[16]; int memsize, i, useword; /* * Detect it again; this gives us the memory size. */ nsc->sc_type = ne2000_detect(nsc); if (nsc->sc_type == 0) { printf("%s: where did the card go?\n", dsc->sc_dev.dv_xname); return; } useword = (nsc->sc_type != NE2000_TYPE_NE1000); dsc->cr_proto = ED_CR_RD2; /* * DCR gets: * * FIFO threshold to 8, No auto-init Remote DMA, * byte order=80x86. * * NE1000 gets byte-wide DMA, NE2000 gets word-wide DMA. */ dsc->dcr_reg = ED_DCR_FT1 | ED_DCR_LS | (nsc->sc_type != NE2000_TYPE_NE1000 ? ED_DCR_WTS : 0); dsc->test_mem = ne2000_test_mem; dsc->ring_copy = ne2000_ring_copy; dsc->write_mbuf = ne2000_write_mbuf; dsc->read_hdr = ne2000_read_hdr; /* Registers are linear. */ for (i = 0; i < 16; i++) dsc->sc_reg_map[i] = i; /* * 8k of memory plus an additional 8k if an NE2000. */ memsize = 8192 + (nsc->sc_type != NE2000_TYPE_NE1000 ? 8192 : 0); /* * NIC memory doens't start at zero on an NE board. * The start address is tied to the bus width. * (It happens to be computed the same way as mem size.) */ dsc->mem_start = memsize; #ifdef GWETHER { int x, mstart = 0; int8_t pbuf0[ED_PAGE_SIZE], pbuf[ED_PAGE_SIZE], tbuf[ED_PAGE_SIZE]; for (i = 0; i < ED_PAGE_SIZE; i++) pbuf0[i] = 0; /* Search for the start of RAM. */ for (x = 1; x < 256; x++) { ne2000_writemem(nict, nich, asict, asich, pbuf0, x << ED_PAGE_SHIFT, ED_PAGE_SIZE, useword); ne2000_readmem(nict, nich, asict, asich, x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE, useword); if (bcmp(pbuf0, tbuf, ED_PAGE_SIZE) == 0) { for (i = 0; i < ED_PAGE_SIZE; i++) pbuf[i] = 255 - x; ne2000_writemem(nict, nich, asict, asich, pbuf, x << ED_PAGE_SHIFT, ED_PAGE_SIZE, useword); ne2000_readmem(nict, nich, asict, asich, x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE, useword); if (bcmp(pbuf, tbuf, ED_PAGE_SIZE) == 0) { mstart = x << ED_PAGE_SHIFT; memsize = ED_PAGE_SIZE; break; } } } if (mstart == 0) { printf("%s: cannot find start of RAM\n", dsc->sc_dev.dv_xname); return; } /* Search for the end of RAM. */ for (++x; x < 256; x++) { ne2000_writemem(nict, nich, asict, asich, pbuf0, x << ED_PAGE_SHIFT, ED_PAGE_SIZE, useword); ne2000_readmem(nict, nich, asict, asich, x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE, useword); if (bcmp(pbuf0, tbuf, ED_PAGE_SIZE) == 0) { for (i = 0; i < ED_PAGE_SIZE; i++) pbuf[i] = 255 - x; ne2000_writemem(nict, nich, asict, asich, pbuf, x << ED_PAGE_SHIFT, ED_PAGE_SIZE, useword); ne2000_readmem(nict, nich, asict, asich, x << ED_PAGE_SHIFT, tbuf, ED_PAGE_SIZE, useword); if (bcmp(pbuf, tbuf, ED_PAGE_SIZE) == 0) memsize += ED_PAGE_SIZE; else break; } else break; } printf("%s: RAM start 0x%x, size %d\n", dsc->sc_dev.dv_xname, mstart, memsize); dsc->mem_start = mstart; } #endif /* GWETHER */ dsc->mem_size = memsize; if (myea == NULL && nsc->sc_type != NE2000_TYPE_DL10019) { /* Read the station address. */ ne2000_readmem(nict, nich, asict, asich, 0, romdata, sizeof(romdata), useword); for (i = 0; i < ETHER_ADDR_LEN; i++) #ifdef __NetBSD__ dsc->sc_enaddr[i] = romdata[i * (useword ? 2 : 1)]; #else dsc->sc_arpcom.ac_enaddr[i] = romdata[i * (useword ? 2 : 1)]; #endif } /* Clear any pending interrupts that might have occurred above. */ bus_space_write_1(nict, nich, ED_P0_ISR, 0xff); if (dp8390_config(dsc, media, nmedia, defmedia)) { printf("%s: setup failed\n", dsc->sc_dev.dv_xname); return; } /* * We need to compute mem_ring a bit differently; override the * value set up in dp8390_config(). */ dsc->mem_ring = dsc->mem_start + ((dsc->txb_cnt * ED_TXBUF_SIZE) << ED_PAGE_SHIFT); } /* * Detect an NE-2000 or compatible. Returns a model code. */ int ne2000_detect(nsc) struct ne2000_softc *nsc; { struct dp8390_softc *dsc = &nsc->sc_dp8390; bus_space_tag_t nict = dsc->sc_regt; bus_space_handle_t nich = dsc->sc_regh; bus_space_tag_t asict = nsc->sc_asict; bus_space_handle_t asich = nsc->sc_asich; static u_int8_t test_pattern[32] = "THIS is A memory TEST pattern"; u_int8_t test_buffer[32], tmp; int i, rv = 0; /* Reset the board. */ #ifdef GWETHER bus_space_write_1(asict, asich, NE2000_ASIC_RESET, 0); delay(200); #endif /* GWETHER */ tmp = bus_space_read_1(asict, asich, NE2000_ASIC_RESET); delay(10000); /* * I don't know if this is necessary; probably cruft leftover from * Clarkson packet driver code. Doesn't do a thing on the boards I've * tested. -DG [note that a outb(0x84, 0) seems to work here, and is * non-invasive...but some boards don't seem to reset and I don't have * complete documentation on what the 'right' thing to do is...so we do * the invasive thing for now. Yuck.] */ bus_space_write_1(asict, asich, NE2000_ASIC_RESET, tmp); delay(5000); /* * This is needed because some NE clones apparently don't reset the * NIC properly (or the NIC chip doesn't reset fully on power-up). * XXX - this makes the probe invasive! Done against my better * judgement. -DLG */ bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STP); delay(5000); /* * Generic probe routine for testing for the existance of a DS8390. * Must be performed after the NIC has just been reset. This * works by looking at certain register values that are guaranteed * to be initialized a certain way after power-up or reset. * * Specifically: * * Register reset bits set bits * -------- ---------- -------- * CR TXP, STA RD2, STP * ISR RST * IMR * DCR LAS * TCR LB1, LB0 * * We only look at CR and ISR, however, since looking at the others * would require changing register pages, which would be intrusive * if this isn't an 8390. */ tmp = bus_space_read_1(nict, nich, ED_P0_CR); if ((tmp & (ED_CR_RD2 | ED_CR_TXP | ED_CR_STA | ED_CR_STP)) != (ED_CR_RD2 | ED_CR_STP)) goto out; tmp = bus_space_read_1(nict, nich, ED_P0_ISR); if ((tmp & ED_ISR_RST) != ED_ISR_RST) goto out; bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA); for (i = 0; i < 100; i++) { if ((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RST) == ED_ISR_RST) { /* Ack the reset bit. */ bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RST); break; } delay(100); } #if 0 /* XXX */ if (i == 100) goto out; #endif /* * Test the ability to read and write to the NIC memory. This has * the side effect of determining if this is an NE1000 or an NE2000. */ /* * This prevents packets from being stored in the NIC memory when * the readmem routine turns on the start bit in the CR. */ bus_space_write_1(nict, nich, ED_P0_RCR, ED_RCR_MON); /* Temporarily initialize DCR for byte operations. */ bus_space_write_1(nict, nich, ED_P0_DCR, ED_DCR_FT1 | ED_DCR_LS); bus_space_write_1(nict, nich, ED_P0_PSTART, 8192 >> ED_PAGE_SHIFT); bus_space_write_1(nict, nich, ED_P0_PSTOP, 16384 >> ED_PAGE_SHIFT); /* * Write a test pattern in byte mode. If this fails, then there * probably isn't any memory at 8k - which likely means that the * board is an NE2000. */ ne2000_writemem(nict, nich, asict, asich, test_pattern, 8192, sizeof(test_pattern), 0); ne2000_readmem(nict, nich, asict, asich, 8192, test_buffer, sizeof(test_buffer), 0); if (bcmp(test_pattern, test_buffer, sizeof(test_pattern))) { /* not an NE1000 - try NE2000 */ bus_space_write_1(nict, nich, ED_P0_DCR, ED_DCR_WTS | ED_DCR_FT1 | ED_DCR_LS); bus_space_write_1(nict, nich, ED_P0_PSTART, 16384 >> ED_PAGE_SHIFT); bus_space_write_1(nict, nich, ED_P0_PSTOP, 32768 >> ED_PAGE_SHIFT); /* * Write the test pattern in word mode. If this also fails, * then we don't know what this board is. */ ne2000_writemem(nict, nich, asict, asich, test_pattern, 16384, sizeof(test_pattern), 1); ne2000_readmem(nict, nich, asict, asich, 16384, test_buffer, sizeof(test_buffer), 1); if (bcmp(test_pattern, test_buffer, sizeof(test_pattern))) goto out; /* not an NE2000 either */ rv = NE2000_TYPE_NE2000; } else { tmp = 0; for (i = 4; i < 12; i++) tmp += bus_space_read_1(asict, asich, i); if (tmp == 0xff) { for (i = 0; i < ETHER_ADDR_LEN; i++) dsc->sc_arpcom.ac_enaddr[i] = bus_space_read_1(asict, asich, i + 4); rv = NE2000_TYPE_DL10019; } else { /* We're an NE1000. */ rv = NE2000_TYPE_NE1000; } } /* Clear any pending interrupts that might have occurred above. */ bus_space_write_1(nict, nich, ED_P0_ISR, 0xff); out: return (rv); } /* * Write an mbuf chain to the destination NIC memory address using programmed * I/O. */ int ne2000_write_mbuf(sc, m, buf) struct dp8390_softc *sc; struct mbuf *m; int buf; { struct ne2000_softc *nsc = (struct ne2000_softc *)sc; bus_space_tag_t nict = sc->sc_regt; bus_space_handle_t nich = sc->sc_regh; bus_space_tag_t asict = nsc->sc_asict; bus_space_handle_t asich = nsc->sc_asich; int savelen; int maxwait = 100; /* about 120us */ savelen = m->m_pkthdr.len; /* Select page 0 registers. */ bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA); /* Reset remote DMA complete flag. */ bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RDC); /* Set up DMA byte count. */ bus_space_write_1(nict, nich, ED_P0_RBCR0, savelen); bus_space_write_1(nict, nich, ED_P0_RBCR1, savelen >> 8); /* Set up destination address in NIC mem. */ bus_space_write_1(nict, nich, ED_P0_RSAR0, buf); bus_space_write_1(nict, nich, ED_P0_RSAR1, buf >> 8); /* Set remote DMA write. */ bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD1 | ED_CR_PAGE_0 | ED_CR_STA); /* * Transfer the mbuf chain to the NIC memory. NE2000 cards * require that data be transferred as words, and only words, * so that case requires some extra code to patch over odd-length * mbufs. */ if (nsc->sc_type == NE2000_TYPE_NE1000) { /* NE1000s are easy. */ for (; m != 0; m = m->m_next) { if (m->m_len) { bus_space_write_multi_1(asict, asich, NE2000_ASIC_DATA, mtod(m, u_int8_t *), m->m_len); } } } else { /* NE2000s are a bit trickier. */ u_int8_t *data, savebyte[2]; int l, leftover; #ifdef DIAGNOSTIC u_int8_t *lim; #endif /* Start out with no leftover data. */ leftover = 0; savebyte[0] = savebyte[1] = 0; for (; m != 0; m = m->m_next) { l = m->m_len; if (l == 0) continue; data = mtod(m, u_int8_t *); #ifdef DIAGNOSTIC lim = data + l; #endif while (l > 0) { if (leftover) { /* * Data left over (from mbuf or * realignment). Buffer the next * byte, and write it and the * leftover data out. */ savebyte[1] = *data++; l--; #ifdef __NetBSD__ bus_space_write_stream_2(asict, asich, NE2000_ASIC_DATA, *(u_int16_t *)savebyte); #else bus_space_write_raw_multi_2(asict, asich, NE2000_ASIC_DATA, savebyte, 2); #endif leftover = 0; #ifdef i386 #define ALIGNED_POINTER(p,t) 1 #endif #ifdef alpha #define ALIGNED_POINTER(p,t) ((((u_long)(p)) & (sizeof(t)-1)) == 0) #endif } else if (ALIGNED_POINTER(data, u_int16_t) == 0) { /* * Unaligned data; buffer the next * byte. */ savebyte[0] = *data++; l--; leftover = 1; } else { /* * Aligned data; output contiguous * words as much as we can, then * buffer the remaining byte, if any. */ leftover = l & 1; l &= ~1; #ifdef __NetBSD__ bus_space_write_multi_stream_2(asict, asich, NE2000_ASIC_DATA, (u_int16_t *)data, l >> 1); #else bus_space_write_raw_multi_2(asict, asich, NE2000_ASIC_DATA, data, l); #endif data += l; if (leftover) savebyte[0] = *data++; l = 0; } } if (l < 0) panic("ne2000_write_mbuf: negative len"); #ifdef DIAGNOSTIC if (data != lim) panic("ne2000_write_mbuf: data != lim"); #endif } if (leftover) { savebyte[1] = 0; #ifdef __NetBSD__ bus_space_write_stream_2(asict, asich, NE2000_ASIC_DATA, *(u_int16_t *)savebyte); #else bus_space_write_raw_multi_2(asict, asich, NE2000_ASIC_DATA, savebyte, 2); #endif } } /* * Wait for remote DMA to complete. This is necessary because on the * transmit side, data is handled internally by the NIC in bursts, and * we can't start another remote DMA until this one completes. Not * waiting causes really bad things to happen - like the NIC wedging * the bus. */ while (((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RDC) != ED_ISR_RDC) && --maxwait); if (maxwait == 0) { log(LOG_WARNING, "%s: remote transmit DMA failed to complete\n", sc->sc_dev.dv_xname); dp8390_reset(sc); } return (savelen); } /* * Given a source and destination address, copy 'amout' of a packet from * the ring buffer into a linear destination buffer. Takes into account * ring-wrap. */ int ne2000_ring_copy(sc, src, dst, amount) struct dp8390_softc *sc; int src; caddr_t dst; u_short amount; { struct ne2000_softc *nsc = (struct ne2000_softc *)sc; bus_space_tag_t nict = sc->sc_regt; bus_space_handle_t nich = sc->sc_regh; bus_space_tag_t asict = nsc->sc_asict; bus_space_handle_t asich = nsc->sc_asich; u_short tmp_amount; int useword = (nsc->sc_type != NE2000_TYPE_NE1000); /* Does copy wrap to lower addr in ring buffer? */ if (src + amount > sc->mem_end) { tmp_amount = sc->mem_end - src; /* Copy amount up to end of NIC memory. */ ne2000_readmem(nict, nich, asict, asich, src, (u_int8_t *)dst, tmp_amount, useword); amount -= tmp_amount; src = sc->mem_ring; dst += tmp_amount; } ne2000_readmem(nict, nich, asict, asich, src, (u_int8_t *)dst, amount, useword); return (src + amount); } void ne2000_read_hdr(sc, buf, hdr) struct dp8390_softc *sc; int buf; struct dp8390_ring *hdr; { struct ne2000_softc *nsc = (struct ne2000_softc *)sc; ne2000_readmem(sc->sc_regt, sc->sc_regh, nsc->sc_asict, nsc->sc_asich, buf, (u_int8_t *)hdr, sizeof(struct dp8390_ring), (nsc->sc_type != NE2000_TYPE_NE1000)); #if BYTE_ORDER == BIG_ENDIAN hdr->count = swap16(hdr->count); #endif } int ne2000_test_mem(sc) struct dp8390_softc *sc; { /* Noop. */ return (0); } /* * Given a NIC memory source address and a host memory destination address, * copy 'amount' from NIC to host using programmed i/o. The 'amount' is * rounded up to a word - ok as long as mbufs are word sized. */ void ne2000_readmem(nict, nich, asict, asich, src, dst, amount, useword) bus_space_tag_t nict; bus_space_handle_t nich; bus_space_tag_t asict; bus_space_handle_t asich; int src; u_int8_t *dst; size_t amount; int useword; { /* Select page 0 registers. */ bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA); /* Round up to a word. */ if (amount & 1) ++amount; /* Set up DMA byte count. */ bus_space_write_1(nict, nich, ED_P0_RBCR0, amount); bus_space_write_1(nict, nich, ED_P0_RBCR1, amount >> 8); /* Set up source address in NIC mem. */ bus_space_write_1(nict, nich, ED_P0_RSAR0, src); bus_space_write_1(nict, nich, ED_P0_RSAR1, src >> 8); bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD0 | ED_CR_PAGE_0 | ED_CR_STA); if (useword) #ifdef __NetBSD__ bus_space_read_multi_stream_2(asict, asich, NE2000_ASIC_DATA, (u_int16_t *)dst, amount >> 1); #else bus_space_read_raw_multi_2(asict, asich, NE2000_ASIC_DATA, dst, amount); #endif else bus_space_read_multi_1(asict, asich, NE2000_ASIC_DATA, dst, amount); } /* * Stripped down routine for writing a linear buffer to NIC memory. Only * used in the probe routine to test the memory. 'len' must be even. */ void ne2000_writemem(nict, nich, asict, asich, src, dst, len, useword) bus_space_tag_t nict; bus_space_handle_t nich; bus_space_tag_t asict; bus_space_handle_t asich; u_int8_t *src; int dst; size_t len; int useword; { int maxwait = 100; /* about 120us */ /* Select page 0 registers. */ bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD2 | ED_CR_PAGE_0 | ED_CR_STA); /* Reset remote DMA complete flag. */ bus_space_write_1(nict, nich, ED_P0_ISR, ED_ISR_RDC); /* Set up DMA byte count. */ bus_space_write_1(nict, nich, ED_P0_RBCR0, len); bus_space_write_1(nict, nich, ED_P0_RBCR1, len >> 8); /* Set up destination address in NIC mem. */ bus_space_write_1(nict, nich, ED_P0_RSAR0, dst); bus_space_write_1(nict, nich, ED_P0_RSAR1, dst >> 8); /* Set remote DMA write. */ bus_space_write_1(nict, nich, ED_P0_CR, ED_CR_RD1 | ED_CR_PAGE_0 | ED_CR_STA); if (useword) #ifdef __NetBSD__ bus_space_write_multi_stream_2(asict, asich, NE2000_ASIC_DATA, (u_int16_t *)src, len >> 1); #else bus_space_write_raw_multi_2(asict, asich, NE2000_ASIC_DATA, src, len); #endif else bus_space_write_multi_1(asict, asich, NE2000_ASIC_DATA, src, len); /* * Wait for remote DMA to complete. This is necessary because on the * transmit side, data is handled internally by the NIC in bursts, and * we can't start another remote DMA until this one completes. Not * waiting causes really bad things to happen - like the NIC wedging * the bus. */ while (((bus_space_read_1(nict, nich, ED_P0_ISR) & ED_ISR_RDC) != ED_ISR_RDC) && --maxwait); }