sys/kern/subr_busdma.c

   1 /*
   2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Sepherosa Ziehau <sepherosa@gmail.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/systm.h>
  37 #include <sys/bus_dma.h>
  38 #include <sys/mbuf.h>
  39
  40 static void
  41 _bus_dmamem_coherent_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
  42 {
  43         bus_addr_t *addr = arg;
  44
  45         if (error)
  46                 return;
  47
  48         KASSERT(nseg == 1, ("too many DMA segments, %d should be 1", nseg));
  49         *addr = segs->ds_addr;
  50 }
  51
  52 int
  53 bus_dmamem_coherent(bus_dma_tag_t parent,
  54                     bus_size_t alignment, bus_size_t boundary,
  55                     bus_addr_t lowaddr, bus_addr_t highaddr,
  56                     bus_size_t maxsize, int flags,
  57                     bus_dmamem_t *dmem)
  58 {
  59         int error;
  60
  61         bzero(dmem, sizeof(*dmem));
  62
  63         error = bus_dma_tag_create(parent, alignment, boundary,
  64                                    lowaddr, highaddr, NULL, NULL,
  65                                    maxsize, 1, maxsize, 0,
  66                                    &dmem->dmem_tag);
  67         if (error)
  68                 return error;
  69
  70         error = bus_dmamem_alloc(dmem->dmem_tag, &dmem->dmem_addr,
  71                                  flags | BUS_DMA_COHERENT, &dmem->dmem_map);
  72         if (error) {
  73                 bus_dma_tag_destroy(dmem->dmem_tag);
  74                 bzero(dmem, sizeof(*dmem));
  75                 return error;
  76         }
  77
  78         error = bus_dmamap_load(dmem->dmem_tag, dmem->dmem_map,
  79                                 dmem->dmem_addr, maxsize,
  80                                 _bus_dmamem_coherent_cb, &dmem->dmem_busaddr,
  81                                 flags & BUS_DMA_NOWAIT);
  82         if (error) {
  83                 if (error == EINPROGRESS) {
  84                         panic("DMA coherent memory loading is still "
  85                               "in progress\n");
  86                 }
  87                 bus_dmamem_free(dmem->dmem_tag, dmem->dmem_addr,
  88                                 dmem->dmem_map);
  89                 bus_dma_tag_destroy(dmem->dmem_tag);
  90                 bzero(dmem, sizeof(*dmem));
  91                 return error;
  92         }
  93         return 0;
  94 }
  95
  96 void *
  97 bus_dmamem_coherent_any(bus_dma_tag_t parent,
  98                         bus_size_t alignment, bus_size_t size, int flags,
  99                         bus_dma_tag_t *dtag, bus_dmamap_t *dmap,
 100                         bus_addr_t *busaddr)
 101 {
 102         bus_dmamem_t dmem;
 103         int error;
 104
 105         error = bus_dmamem_coherent(parent, alignment, 0,
 106                                     BUS_SPACE_MAXADDR, BUS_SPACE_MAXADDR,
 107                                     size, flags, &dmem);
 108         if (error)
 109                 return NULL;
 110
 111         *dtag = dmem.dmem_tag;
 112         *dmap = dmem.dmem_map;
 113         *busaddr = dmem.dmem_busaddr;
 114
 115         return dmem.dmem_addr;
 116 }
 117
 118 int
 119 bus_dmamap_load_mbuf_defrag(bus_dma_tag_t dmat, bus_dmamap_t map,
 120                             struct mbuf **m_head,
 121                             bus_dma_segment_t *segs, int maxsegs,
 122                             int *nsegs, int flags)
 123 {
 124         struct mbuf *m = *m_head;
 125         int error;
 126
 127         error = bus_dmamap_load_mbuf_segment(dmat, map, m,
 128                         segs, maxsegs, nsegs, flags);
 129         if (error == EFBIG) {
 130                 struct mbuf *m_new;
 131
 132                 m_new = m_defrag(m, MB_DONTWAIT);
 133                 if (m_new == NULL)
 134                         return ENOBUFS;
 135                 else
 136                         *m_head = m = m_new;
 137
 138                 error = bus_dmamap_load_mbuf_segment(dmat, map, m,
 139                                 segs, maxsegs, nsegs, flags);
 140         }
 141         return error;
 142 }