text: /*	$NetBSD: if_uba.c,v 1.22 2001/11/13 07:11:24 lukem Exp $	*/
  
  /*
   * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
   * All rights reserved.
   *
   * 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 University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
   *
   *	@(#)if_uba.c	7.16 (Berkeley) 12/16/90
   */
  
  #include <sys/cdefs.h>
  __KERNEL_RCSID(0, "$NetBSD: if_uba.c,v 1.22 2001/11/13 07:11:24 lukem Exp $");
  
  #include <sys/param.h>
  #include <sys/systm.h>
  #include <sys/malloc.h>
  #include <sys/mbuf.h>
  #include <sys/socket.h>
  #include <sys/device.h>
  
  #include <net/if.h>
  
  #include <machine/bus.h>
  
  #include <dev/qbus/if_uba.h>
  #include <dev/qbus/ubareg.h>
  #include <dev/qbus/ubavar.h>
  
  static	struct mbuf *getmcl(void);
  
  /*
   * Routines supporting UNIBUS network interfaces.
   *
   * TODO:
   *	Support interfaces using only one BDP statically.
   */
  
  /*
   * Init UNIBUS for interface whose headers of size hlen are to
   * end on a page boundary.  We allocate a UNIBUS map register for the page
   * with the header, and nmr more UNIBUS map registers for i/o on the adapter,
   * doing this once for each read and once for each write buffer.  We also
   * allocate page frames in the mbuffer pool for these pages.
   *
   * Recent changes:
   *	No special "header pages" anymore.
   *	Recv packets are always put in clusters.
   *	"size" is the maximum buffer size, may not be bigger than MCLBYTES.
   */
  int
  if_ubaminit(struct ifubinfo *ifu, struct uba_softc *uh, int size,
      struct ifrw *ifr, int nr, struct ifxmt *ifw, int nw)
  {
  	struct mbuf *m;
  	int totsz, i, error, rseg, nm = nr;
  	bus_dma_segment_t seg;
  	caddr_t vaddr;
  
  #ifdef DIAGNOSTIC
  	if (size > MCLBYTES)
  		panic("if_ubaminit: size > MCLBYTES");
  #endif
  	ifu->iff_softc = uh;
  	/*
  	 * Get DMA memory for transmit buffers.
  	 * Buffer size are rounded up to a multiple of the uba page size,
  	 * then allocated contiguous.
  	 */
  	size = (size + UBA_PGOFSET) & ~UBA_PGOFSET;
  	totsz = size * nw;
  	if ((error = bus_dmamem_alloc(uh->uh_dmat, totsz, NBPG, 0,
  	    &seg, 1, &rseg, BUS_DMA_NOWAIT)))
  		return error;
  	if ((error = bus_dmamem_map(uh->uh_dmat, &seg, rseg, totsz, &vaddr,
  	    BUS_DMA_NOWAIT|BUS_DMA_COHERENT))) {
  		bus_dmamem_free(uh->uh_dmat, &seg, rseg);
  		return error;
  	}
  
  	/*
  	 * Create receive and transmit maps.
  	 * Alloc all resources now so we won't fail in the future.
  	 */
  
  	for (i = 0; i < nr; i++) {
  		if ((error = bus_dmamap_create(uh->uh_dmat, size, 1,
  		    size, 0, BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
  		    &ifr[i].ifrw_map))) {
  			nr = i;
  			nm = nw = 0;
  			goto bad;
  		}
  	}
  	for (i = 0; i < nw; i++) {
  		if ((error = bus_dmamap_create(uh->uh_dmat, size, 1,
  		    size, 0, BUS_DMA_NOWAIT|BUS_DMA_ALLOCNOW,
  		    &ifw[i].ifw_map))) {
  			nw = i;
  			nm = 0;
  			goto bad;
  		}
  	}
  	/*
  	 * Preload the rx maps with mbuf clusters.
  	 */
  	for (i = 0; i < nm; i++) {
  		if ((m = getmcl()) == NULL) {
  			nm = i;
  			goto bad;
  		}
  		ifr[i].ifrw_mbuf = m;
  		bus_dmamap_load(uh->uh_dmat, ifr[i].ifrw_map,
  		    m->m_ext.ext_buf, m->m_ext.ext_size, NULL, BUS_DMA_NOWAIT);
  		
  	}
  	/*
  	 * Load the tx maps with DMA memory (common case).
  	 */
  	for (i = 0; i < nw; i++) {
  		ifw[i].ifw_vaddr = vaddr + size * i;
  		ifw[i].ifw_size = size;
  		bus_dmamap_load(uh->uh_dmat, ifw[i].ifw_map, 
  		    ifw[i].ifw_vaddr, ifw[i].ifw_size, NULL, BUS_DMA_NOWAIT);
  	}
  	return 0;
  bad:
  	while (--nm >= 0) {
  		bus_dmamap_unload(uh->uh_dmat, ifr[nw].ifrw_map);
  		m_freem(ifr[nm].ifrw_mbuf);
  	}
  	while (--nw >= 0)
  		bus_dmamap_destroy(uh->uh_dmat, ifw[nw].ifw_map);
  	while (--nr >= 0)
  		bus_dmamap_destroy(uh->uh_dmat, ifr[nw].ifrw_map);
  	return (0);
  }
  
  struct mbuf *
  getmcl()
  {
  	struct mbuf *m;
  
  	MGETHDR(m, M_DONTWAIT, MT_DATA);
  	if (m == NULL)
  		return 0;
  	MCLGET(m, M_DONTWAIT);
  	if ((m->m_flags & M_EXT) == 0) {
  		m_freem(m);
  		return 0;
  	}
  	return m;
  }
  
  /*
   * Pull read data off a interface.
   * Totlen is length of data, with local net header stripped.
   * When full cluster sized units are present
   * on the interface on cluster boundaries we can get them more
   * easily by remapping, and take advantage of this here.
   * Save a pointer to the interface structure and the total length,
   * so that protocols can determine where incoming packets arrived.
   * Note: we may be called to receive from a transmit buffer by some
   * devices.  In that case, we must force normal mapping of the buffer,
   * so that the correct data will appear (only unibus maps are 
   * changed when remapping the transmit buffers).
   */
  struct mbuf *
  if_ubaget(struct ifubinfo *ifu, struct ifrw *ifr, struct ifnet *ifp, int len)
  {
  	struct uba_softc *uh = ifu->iff_softc;
  	struct mbuf *m, *mn;
  
  	if ((mn = getmcl()) == NULL)
  		return NULL;	/* Leave the old */
  
  	bus_dmamap_unload(uh->uh_dmat, ifr->ifrw_map);
  	m = ifr->ifrw_mbuf;
  	ifr->ifrw_mbuf = mn;
  	if ((bus_dmamap_load(uh->uh_dmat, ifr->ifrw_map,
  	    mn->m_ext.ext_buf, mn->m_ext.ext_size, NULL, BUS_DMA_NOWAIT)))
  		panic("if_ubaget"); /* Cannot happen */
  	m->m_pkthdr.rcvif = ifp;
  	m->m_len = m->m_pkthdr.len = len;
  	return m;
  }
  
  /*
   * Called after a packet is sent. Releases hold resources.
   */
  void
  if_ubaend(struct ifubinfo *ifu, struct ifxmt *ifw)
  {
  	struct uba_softc *uh = ifu->iff_softc;
  
  	if (ifw->ifw_flags & IFRW_MBUF) {
  		bus_dmamap_unload(uh->uh_dmat, ifw->ifw_map);
  		m_freem(ifw->ifw_mbuf);
  		ifw->ifw_mbuf = NULL;
  	}
  }
  
  /*
   * Map a chain of mbufs onto a network interface
   * in preparation for an i/o operation.
   * The argument chain of mbufs includes the local network
   * header which is copied to be in the mapped, aligned
   * i/o space.
   */
  int
  if_ubaput(struct ifubinfo *ifu, struct ifxmt *ifw, struct mbuf *m)
  {
  	struct uba_softc *uh = ifu->iff_softc;
  	int len;
  
  	if (/* m->m_next ==*/ 0) {
  		/*
  		 * Map the outgoing packet directly.
  		 */
  		if ((ifw->ifw_flags & IFRW_MBUF) == 0) {
  			bus_dmamap_unload(uh->uh_dmat, ifw->ifw_map);
  			ifw->ifw_flags |= IFRW_MBUF;
  		}
  		bus_dmamap_load(uh->uh_dmat, ifw->ifw_map, mtod(m, void *),
  		    m->m_len, NULL, BUS_DMA_NOWAIT);
  		ifw->ifw_mbuf = m;
  		len = m->m_len;
  	} else {
  		if (ifw->ifw_flags & IFRW_MBUF) {
  			bus_dmamap_load(uh->uh_dmat, ifw->ifw_map,
  	                    ifw->ifw_vaddr, ifw->ifw_size,NULL,BUS_DMA_NOWAIT);
  			ifw->ifw_flags &= ~IFRW_MBUF;
  		}
  		len = m->m_pkthdr.len;
  		m_copydata(m, 0, m->m_pkthdr.len, ifw->ifw_vaddr);
  		m_freem(m);
  	}
  	return len;
  }
  