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jensenio_dma.c revision 1.5
      1 /* $NetBSD: jensenio_dma.c,v 1.5 2012/02/06 02:14:14 matt 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 1.5 2012/02/06 02:14:14 matt 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 <sys/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 for the 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 }
    160