/*      $NetBSD: if_uba.c,v 1.32 2016/06/10 13:27:15 ozaki-r 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. 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 1.32 2016/06/10 13:27:15 ozaki-r 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 <sys/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;
       void *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, PAGE_SIZE, 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 = (char *)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(void)
{
       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_set_rcvif(m, 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;
}