sys/arch/alpha/jensenio/jensenio_dma.c

   1 /* $NetBSD: jensenio_dma.c,v 1.1 2000/07/12 20:36:09 thorpej Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2000 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Jason R. Thorpe.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * DMA support for the Jensen system.
  34  *
  35  * The Jensen uses direct-mapped DMA with a window base of 0, i.e.
  36  * a page of phyical memory has the same PCI address as CPU address.
  37  * There is no support for SGMAPs on the Jensen.  This means that for
  38  * ISA DMA, we must employ bounce buffers for DMA transactions over
  39  * 16MB ISA limit (due to ISA's 24-bit address space limitation).
  40  *
  41  * Furthermore, the H_BUS will not respond to DMA transactions between
  42  * 512KB and 1MB.  This is to allow for the ISA `hole'.  However, the
  43  * ISA `hole' typically exists only between 640KB and 1MB.  We must
  44  * therefore bounce transactions that fall within this region, as well.
  45  * XXX Should we prevent having managed memory in this region, instead?
  46  */
  47
  48 #include <sys/cdefs.h>                  /* RCS ID & Copyright macro defns */
  49
  50 __KERNEL_RCSID(0, "$NetBSD: jensenio_dma.c,v 1.1 2000/07/12 20:36:09 thorpej Exp $");
  51
  52 #include <sys/param.h>
  53 #include <sys/systm.h>
  54 #include <sys/kernel.h>
  55 #include <sys/device.h>
  56 #include <sys/malloc.h>
  57 #include <sys/mbuf.h>
  58
  59 #define _ALPHA_BUS_DMA_PRIVATE
  60 #include <machine/bus.h>
  61
  62 #include <dev/eisa/eisavar.h>
  63
  64 #include <dev/isa/isavar.h>
  65
  66 #include <alpha/jensenio/jenseniovar.h>
  67
  68 bus_dma_tag_t jensenio_dma_get_tag(bus_dma_tag_t, alpha_bus_t);
  69
  70 void
  71 jensenio_dma_init(struct jensenio_config *jcp)
  72 {
  73         bus_dma_tag_t t;
  74
  75         /*
  76          * Initialize the DMA tag used for EISA DMA.
  77          */
  78         t = &jcp->jc_dmat_eisa;
  79         t->_cookie = jcp;
  80         t->_wbase = 0;
  81         t->_wsize = 0x100000000UL;
  82         t->_next_window = NULL;
  83         t->_boundary = 0;
  84         t->_sgmap = NULL;
  85         t->_get_tag = jensenio_dma_get_tag;
  86         t->_dmamap_create = _bus_dmamap_create;
  87         t->_dmamap_destroy = _bus_dmamap_destroy;
  88         t->_dmamap_load = _bus_dmamap_load_direct;
  89         t->_dmamap_load_mbuf = _bus_dmamap_load_mbuf_direct;
  90         t->_dmamap_load_uio = _bus_dmamap_load_uio_direct;
  91         t->_dmamap_load_raw = _bus_dmamap_load_raw_direct;
  92         t->_dmamap_unload = _bus_dmamap_unload;
  93         t->_dmamap_sync = _bus_dmamap_sync;
  94
  95         t->_dmamem_alloc = _bus_dmamem_alloc;
  96         t->_dmamem_free = _bus_dmamem_free;
  97         t->_dmamem_map = _bus_dmamem_map;
  98         t->_dmamem_unmap = _bus_dmamem_unmap;
  99         t->_dmamem_mmap = _bus_dmamem_mmap;
 100
 101         /*
 102          * Initialize the DMA tag used for ISA DMA.
 103          */
 104         t = &jcp->jc_dmat_isa;
 105         t->_cookie = jcp;
 106         t->_wbase = 0;
 107         t->_wsize = 0x1000000;
 108         t->_next_window = NULL;
 109         t->_boundary = 0;
 110         t->_sgmap = NULL;
 111         t->_get_tag = jensenio_dma_get_tag;
 112         t->_dmamap_create = isadma_bounce_dmamap_create;
 113         t->_dmamap_destroy = isadma_bounce_dmamap_destroy;
 114         t->_dmamap_load = isadma_bounce_dmamap_load;
 115         t->_dmamap_load_mbuf = isadma_bounce_dmamap_load_mbuf;
 116         t->_dmamap_load_uio = isadma_bounce_dmamap_load_uio;
 117         t->_dmamap_load_raw = isadma_bounce_dmamap_load_raw;
 118         t->_dmamap_unload = isadma_bounce_dmamap_unload;
 119         t->_dmamap_sync = isadma_bounce_dmamap_sync;
 120
 121         t->_dmamem_alloc = isadma_bounce_dmamem_alloc;
 122         t->_dmamem_free = _bus_dmamem_free;
 123         t->_dmamem_map = _bus_dmamem_map;
 124         t->_dmamem_unmap = _bus_dmamem_unmap;
 125         t->_dmamem_mmap = _bus_dmamem_mmap;
 126
 127         /* XXX XXX BEGIN XXX XXX */
 128         {                                                       /* XXX */
 129                 extern paddr_t alpha_XXX_dmamap_or;             /* XXX */
 130                 alpha_XXX_dmamap_or = 0;                        /* XXX */
 131         }
 132 }
 133
 134 /*
 135  * Return the bus dma tag to be used fo rthe specified bus type.
 136  * INTERNAL USE ONLY!
 137  */
 138 bus_dma_tag_t
 139 jensenio_dma_get_tag(bus_dma_tag_t t, alpha_bus_t bustype)
 140 {
 141         struct jensenio_config *jcp = t->_cookie;
 142
 143         switch (bustype) {
 144         case ALPHA_BUS_EISA:
 145                 /*
 146                  * Busses capable of 32-bit DMA get the EISA DMA tag.
 147                  */
 148                 return (&jcp->jc_dmat_eisa);
 149
 150         case ALPHA_BUS_ISA:
 151                 /*
 152                  * Lame 24-bit busses have to bounce.
 153                  */
 154                 return (&jcp->jc_dmat_isa);
 155
 156         default:
 157                 panic("jensenio_dma_get_tag: shouldn't be here, really...");
 158         }
 159 }