1 /* $NetBSD: sgmap_common.c,v 1.27 2020/06/17 04:12:39 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 1.27 2020/06/17 04:12:39 thorpej Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 #include <sys/proc.h> 42 43 #include <uvm/uvm_extern.h> 44 45 #define _ALPHA_BUS_DMA_PRIVATE 46 #include <sys/bus.h> 47 48 #include <alpha/common/sgmapvar.h> 49 50 /* 51 * Some systems will prefetch the next page during a memory -> device DMA. 52 * This can cause machine checks if there is not a spill page after the 53 * last page of the DMA (thus avoiding hitting an invalid SGMAP PTE). 54 */ 55 vaddr_t alpha_sgmap_prefetch_spill_page_va; 56 bus_addr_t alpha_sgmap_prefetch_spill_page_pa; 57 58 void 59 alpha_sgmap_init(bus_dma_tag_t t, struct alpha_sgmap *sgmap, const char *name, 60 bus_addr_t wbase, bus_addr_t sgvabase, bus_size_t sgvasize, size_t ptesize, 61 void *ptva, bus_size_t minptalign) 62 { 63 bus_dma_segment_t seg; 64 size_t ptsize; 65 int rseg; 66 67 if (sgvasize & PGOFSET) { 68 printf("size botch for sgmap `%s'\n", name); 69 goto die; 70 } 71 72 sgmap->aps_wbase = wbase; 73 sgmap->aps_sgvabase = sgvabase; 74 sgmap->aps_sgvasize = sgvasize; 75 76 if (ptva != NULL) { 77 /* 78 * We already have a page table; this may be a system 79 * where the page table resides in bridge-resident SRAM. 80 */ 81 sgmap->aps_pt = ptva; 82 sgmap->aps_ptpa = 0; 83 } else { 84 /* 85 * Compute the page table size and allocate it. At minimum, 86 * this must be aligned to the page table size. However, 87 * some platforms have more strict alignment reqirements. 88 */ 89 ptsize = (sgvasize / PAGE_SIZE) * ptesize; 90 if (minptalign != 0) { 91 if (minptalign < ptsize) 92 minptalign = ptsize; 93 } else 94 minptalign = ptsize; 95 if (bus_dmamem_alloc(t, ptsize, minptalign, 0, &seg, 1, &rseg, 96 BUS_DMA_NOWAIT)) { 97 panic("unable to allocate page table for sgmap `%s'", 98 name); 99 goto die; 100 } 101 sgmap->aps_ptpa = seg.ds_addr; 102 sgmap->aps_pt = (void *)ALPHA_PHYS_TO_K0SEG(sgmap->aps_ptpa); 103 } 104 105 /* 106 * Create the arena used to manage the virtual address 107 * space. 108 * 109 * XXX Consider using a quantum cache up to MAXPHYS+PAGE_SIZE 110 * XXX (extra page to handle the spill page). For now, we don't, 111 * XXX because we are using constrained allocations everywhere. 112 */ 113 sgmap->aps_arena = vmem_create(name, sgvabase, sgvasize, 114 PAGE_SIZE, /* quantum */ 115 NULL, /* importfn */ 116 NULL, /* releasefn */ 117 NULL, /* source */ 118 0, /* qcache_max */ 119 VM_SLEEP, 120 IPL_VM); 121 KASSERT(sgmap->aps_arena != NULL); 122 123 /* 124 * Allocate a spill page if that hasn't already been done. 125 */ 126 if (alpha_sgmap_prefetch_spill_page_va == 0) { 127 if (bus_dmamem_alloc(t, PAGE_SIZE, 0, 0, &seg, 1, &rseg, 128 BUS_DMA_NOWAIT)) { 129 printf("unable to allocate spill page for sgmap `%s'\n", 130 name); 131 goto die; 132 } 133 alpha_sgmap_prefetch_spill_page_pa = seg.ds_addr; 134 alpha_sgmap_prefetch_spill_page_va = 135 ALPHA_PHYS_TO_K0SEG(alpha_sgmap_prefetch_spill_page_pa); 136 memset((void *)alpha_sgmap_prefetch_spill_page_va, 0, 137 PAGE_SIZE); 138 } 139 140 return; 141 die: 142 panic("alpha_sgmap_init"); 143 } 144 145 int 146 alpha_sgmap_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments, 147 bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp) 148 { 149 bus_dmamap_t map; 150 int error; 151 152 error = _bus_dmamap_create(t, size, nsegments, maxsegsz, 153 boundary, flags, &map); 154 if (error) 155 return (error); 156 157 /* XXX BUS_DMA_ALLOCNOW */ 158 159 if (error == 0) 160 *dmamp = map; 161 else 162 alpha_sgmap_dmamap_destroy(t, map); 163 164 return (error); 165 } 166 167 void 168 alpha_sgmap_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) 169 { 170 171 KASSERT(map->dm_mapsize == 0); 172 173 _bus_dmamap_destroy(t, map); 174 } 175