1 /* $NetBSD: sgmap_common.c,v 1.29 2021/07/18 05:12:27 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 1997, 1998, 2001 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 of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 34 35 __KERNEL_RCSID(0, "$NetBSD: sgmap_common.c,v 1.29 2021/07/18 05:12:27 thorpej Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/proc.h> 41 42 #include <uvm/uvm_extern.h> 43 44 #define _ALPHA_BUS_DMA_PRIVATE 45 #include <sys/bus.h> 46 47 #include <alpha/common/sgmapvar.h> 48 49 /* 50 * Some systems will prefetch the next page during a memory -> device DMA. 51 * This can cause machine checks if there is not a spill page after the 52 * last page of the DMA (thus avoiding hitting an invalid SGMAP PTE). 53 */ 54 vaddr_t alpha_sgmap_prefetch_spill_page_va; 55 bus_addr_t alpha_sgmap_prefetch_spill_page_pa; 56 57 void 58 alpha_sgmap_init(bus_dma_tag_t t, struct alpha_sgmap *sgmap, const char *name, 59 bus_addr_t wbase, bus_addr_t sgvabase, bus_size_t sgvasize, size_t ptesize, 60 void *ptva, bus_size_t minptalign) 61 { 62 bus_dma_segment_t seg; 63 size_t ptsize; 64 int rseg; 65 66 if (sgvasize & PGOFSET) { 67 printf("size botch for sgmap `%s'\n", name); 68 goto die; 69 } 70 71 /* 72 * If we don't yet have a minimum SGVA alignment, default 73 * to the system page size. 74 */ 75 if (t->_sgmap_minalign < PAGE_SIZE) { 76 t->_sgmap_minalign = PAGE_SIZE; 77 } 78 79 sgmap->aps_wbase = wbase; 80 sgmap->aps_sgvabase = sgvabase; 81 sgmap->aps_sgvasize = sgvasize; 82 83 if (ptva != NULL) { 84 /* 85 * We already have a page table; this may be a system 86 * where the page table resides in bridge-resident SRAM. 87 */ 88 sgmap->aps_pt = ptva; 89 sgmap->aps_ptpa = 0; 90 } else { 91 /* 92 * Compute the page table size and allocate it. At minimum, 93 * this must be aligned to the page table size. However, 94 * some platforms have more strict alignment reqirements. 95 */ 96 ptsize = (sgvasize / PAGE_SIZE) * ptesize; 97 if (minptalign != 0) { 98 if (minptalign < ptsize) 99 minptalign = ptsize; 100 } else 101 minptalign = ptsize; 102 if (bus_dmamem_alloc(t, ptsize, minptalign, 0, &seg, 1, &rseg, 103 BUS_DMA_NOWAIT)) { 104 panic("unable to allocate page table for sgmap `%s'", 105 name); 106 goto die; 107 } 108 sgmap->aps_ptpa = seg.ds_addr; 109 sgmap->aps_pt = (void *)ALPHA_PHYS_TO_K0SEG(sgmap->aps_ptpa); 110 } 111 112 /* 113 * Create the arena used to manage the virtual address 114 * space. 115 * 116 * XXX Consider using a quantum cache up to MAXPHYS+PAGE_SIZE 117 * XXX (extra page to handle the spill page). For now, we don't, 118 * XXX because we are using constrained allocations everywhere. 119 */ 120 sgmap->aps_arena = vmem_create(name, sgvabase, sgvasize, 121 PAGE_SIZE, /* quantum */ 122 NULL, /* importfn */ 123 NULL, /* releasefn */ 124 NULL, /* source */ 125 0, /* qcache_max */ 126 VM_SLEEP, 127 IPL_VM); 128 KASSERT(sgmap->aps_arena != NULL); 129 130 /* 131 * Allocate a spill page if that hasn't already been done. 132 */ 133 if (alpha_sgmap_prefetch_spill_page_va == 0) { 134 if (bus_dmamem_alloc(t, PAGE_SIZE, 0, 0, &seg, 1, &rseg, 135 BUS_DMA_NOWAIT)) { 136 printf("unable to allocate spill page for sgmap `%s'\n", 137 name); 138 goto die; 139 } 140 alpha_sgmap_prefetch_spill_page_pa = seg.ds_addr; 141 alpha_sgmap_prefetch_spill_page_va = 142 ALPHA_PHYS_TO_K0SEG(alpha_sgmap_prefetch_spill_page_pa); 143 memset((void *)alpha_sgmap_prefetch_spill_page_va, 0, 144 PAGE_SIZE); 145 } 146 147 return; 148 die: 149 panic("alpha_sgmap_init"); 150 } 151 152 int 153 alpha_sgmap_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments, 154 bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp) 155 { 156 bus_dmamap_t map; 157 int error; 158 159 error = _bus_dmamap_create(t, size, nsegments, maxsegsz, 160 boundary, flags, &map); 161 if (error) 162 return (error); 163 164 /* XXX BUS_DMA_ALLOCNOW */ 165 166 if (error == 0) 167 *dmamp = map; 168 else 169 alpha_sgmap_dmamap_destroy(t, map); 170 171 return (error); 172 } 173 174 void 175 alpha_sgmap_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) 176 { 177 178 KASSERT(map->dm_mapsize == 0); 179 180 _bus_dmamap_destroy(t, map); 181 } 182
Indexes created Sat Sep 20 22:09:52 GMT 2025