jensenio_dma.c revision 1.7
1 /* $NetBSD: jensenio_dma.c,v 1.7 2020/10/14 00:59:50 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 2000, 2020 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 1.7 2020/10/14 00:59:50 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 <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 #include <machine/alpha.h> 69 70 bus_dma_tag_t jensenio_dma_get_tag(bus_dma_tag_t, alpha_bus_t); 71 72 void 73 jensenio_page_physload(unsigned long const start_pfn, 74 unsigned long const end_pfn) 75 { 76 /* 77 * The Jensen does not have SGMAP DMA. For this reason, we 78 * need to protect the first 16MB of RAM from random allocations 79 * in order to give ISA DMA a snowball's chance of working. 80 */ 81 alpha_page_physload_sheltered(start_pfn, end_pfn, 82 0, alpha_btop(0x1000000)); 83 } 84 85 void 86 jensenio_dma_init(struct jensenio_config *jcp) 87 { 88 bus_dma_tag_t t; 89 90 /* 91 * Initialize the DMA tag used for EISA DMA. 92 */ 93 t = &jcp->jc_dmat_eisa; 94 t->_cookie = jcp; 95 t->_wbase = 0; 96 t->_wsize = 0x100000000UL; 97 t->_next_window = NULL; 98 t->_boundary = 0; 99 t->_sgmap = NULL; 100 t->_get_tag = jensenio_dma_get_tag; 101 t->_dmamap_create = _bus_dmamap_create; 102 t->_dmamap_destroy = _bus_dmamap_destroy; 103 t->_dmamap_load = _bus_dmamap_load_direct; 104 t->_dmamap_load_mbuf = _bus_dmamap_load_mbuf_direct; 105 t->_dmamap_load_uio = _bus_dmamap_load_uio_direct; 106 t->_dmamap_load_raw = _bus_dmamap_load_raw_direct; 107 t->_dmamap_unload = _bus_dmamap_unload; 108 t->_dmamap_sync = _bus_dmamap_sync; 109 110 t->_dmamem_alloc = _bus_dmamem_alloc; 111 t->_dmamem_free = _bus_dmamem_free; 112 t->_dmamem_map = _bus_dmamem_map; 113 t->_dmamem_unmap = _bus_dmamem_unmap; 114 t->_dmamem_mmap = _bus_dmamem_mmap; 115 116 /* 117 * Initialize the DMA tag used for ISA DMA. 118 */ 119 t = &jcp->jc_dmat_isa; 120 t->_cookie = jcp; 121 t->_wbase = 0; 122 t->_wsize = 0x1000000; 123 t->_next_window = NULL; 124 t->_boundary = 0; 125 t->_sgmap = NULL; 126 t->_get_tag = jensenio_dma_get_tag; 127 t->_dmamap_create = isadma_bounce_dmamap_create; 128 t->_dmamap_destroy = isadma_bounce_dmamap_destroy; 129 t->_dmamap_load = isadma_bounce_dmamap_load; 130 t->_dmamap_load_mbuf = isadma_bounce_dmamap_load_mbuf; 131 t->_dmamap_load_uio = isadma_bounce_dmamap_load_uio; 132 t->_dmamap_load_raw = isadma_bounce_dmamap_load_raw; 133 t->_dmamap_unload = isadma_bounce_dmamap_unload; 134 t->_dmamap_sync = isadma_bounce_dmamap_sync; 135 136 t->_dmamem_alloc = isadma_bounce_dmamem_alloc; 137 t->_dmamem_free = _bus_dmamem_free; 138 t->_dmamem_map = _bus_dmamem_map; 139 t->_dmamem_unmap = _bus_dmamem_unmap; 140 t->_dmamem_mmap = _bus_dmamem_mmap; 141 } 142 143 /* 144 * Return the bus dma tag to be used for the specified bus type. 145 * INTERNAL USE ONLY! 146 */ 147 bus_dma_tag_t 148 jensenio_dma_get_tag(bus_dma_tag_t t, alpha_bus_t bustype) 149 { 150 struct jensenio_config *jcp = t->_cookie; 151 152 switch (bustype) { 153 case ALPHA_BUS_EISA: 154 /* 155 * Busses capable of 32-bit DMA get the EISA DMA tag. 156 */ 157 return (&jcp->jc_dmat_eisa); 158 159 case ALPHA_BUS_ISA: 160 /* 161 * Lame 24-bit busses have to bounce. 162 */ 163 return (&jcp->jc_dmat_isa); 164 165 default: 166 panic("jensenio_dma_get_tag: shouldn't be here, really..."); 167 } 168 } 169
Indexes created Tue Sep 30 20:09:53 GMT 2025