1 /* $NetBSD: linux_io_mapping.c,v 1.1 2021/12/19 12:28:04 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2013-2021 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: linux_io_mapping.c,v 1.1 2021/12/19 12:28:04 riastradh Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/kmem.h> 35 #include <sys/systm.h> 36 #include <sys/mman.h> 37 38 #include <uvm/uvm_extern.h> 39 40 #include <linux/io-mapping.h> 41 42 bool 43 bus_space_io_mapping_init_wc(bus_space_tag_t bst, struct io_mapping *mapping, 44 bus_addr_t addr, bus_size_t size) 45 { 46 bus_size_t offset; 47 48 KASSERT(PAGE_SIZE <= size); 49 KASSERT(0 == (size & (PAGE_SIZE - 1))); 50 KASSERT(__type_fit(off_t, size)); 51 52 /* 53 * XXX For x86: Reserve the region (bus_space_reserve) and set 54 * an MTRR to make it write-combining. Doesn't matter if we 55 * have PAT and we use pmap_kenter_pa, but matters if we don't 56 * have PAT or if we later make this use direct map. 57 */ 58 59 /* Make sure the region is mappable. */ 60 for (offset = 0; offset < size; offset += PAGE_SIZE) { 61 if (bus_space_mmap(bst, addr, offset, PROT_READ|PROT_WRITE, 62 BUS_SPACE_MAP_LINEAR|BUS_SPACE_MAP_PREFETCHABLE) 63 == (paddr_t)-1) 64 return false; 65 } 66 67 /* Initialize the mapping record. */ 68 mapping->diom_bst = bst; 69 mapping->base = addr; 70 mapping->size = size; 71 mapping->diom_atomic = false; 72 73 /* Allocate kva for one page. */ 74 mapping->diom_va = uvm_km_alloc(kernel_map, PAGE_SIZE, PAGE_SIZE, 75 UVM_KMF_VAONLY | UVM_KMF_WAITVA); 76 KASSERT(mapping->diom_va != 0); 77 78 return true; 79 } 80 81 void 82 io_mapping_fini(struct io_mapping *mapping) 83 { 84 85 KASSERT(!mapping->diom_atomic); 86 87 uvm_km_free(kernel_map, mapping->diom_va, PAGE_SIZE, UVM_KMF_VAONLY); 88 mapping->diom_va = 0; /* paranoia */ 89 } 90 91 struct io_mapping * 92 bus_space_io_mapping_create_wc(bus_space_tag_t bst, bus_addr_t addr, 93 bus_size_t size) 94 { 95 struct io_mapping *mapping; 96 97 mapping = kmem_alloc(sizeof(*mapping), KM_SLEEP); 98 if (!bus_space_io_mapping_init_wc(bst, mapping, addr, size)) { 99 kmem_free(mapping, sizeof(*mapping)); 100 return NULL; 101 } 102 103 return mapping; 104 } 105 106 void 107 io_mapping_free(struct io_mapping *mapping) 108 { 109 110 io_mapping_fini(mapping); 111 kmem_free(mapping, sizeof(*mapping)); 112 } 113 114 void * 115 io_mapping_map_wc(struct io_mapping *mapping, bus_addr_t offset, 116 bus_size_t size) 117 { 118 bus_size_t pg, npgs = size >> PAGE_SHIFT; 119 vaddr_t va; 120 paddr_t cookie; 121 122 KASSERT(0 == (offset & (PAGE_SIZE - 1))); 123 KASSERT(PAGE_SIZE <= mapping->size); 124 KASSERT(offset <= (mapping->size - PAGE_SIZE)); 125 KASSERT(__type_fit(off_t, offset)); 126 127 va = uvm_km_alloc(kernel_map, size, PAGE_SIZE, 128 UVM_KMF_VAONLY|UVM_KMF_WAITVA); 129 KASSERT(va != mapping->diom_va); 130 for (pg = 0; pg < npgs; pg++) { 131 cookie = bus_space_mmap(mapping->diom_bst, mapping->base, 132 offset + pg*PAGE_SIZE, 133 PROT_READ|PROT_WRITE, 134 BUS_SPACE_MAP_LINEAR|BUS_SPACE_MAP_PREFETCHABLE); 135 KASSERT(cookie != (paddr_t)-1); 136 137 pmap_kenter_pa(va + pg*PAGE_SIZE, pmap_phys_address(cookie), 138 PROT_READ|PROT_WRITE, pmap_mmap_flags(cookie)); 139 } 140 pmap_update(pmap_kernel()); 141 142 return (void *)va; 143 } 144 145 void 146 io_mapping_unmap(struct io_mapping *mapping, void *ptr, bus_size_t size) 147 { 148 vaddr_t va = (vaddr_t)ptr; 149 150 KASSERT(mapping->diom_va != va); 151 152 pmap_kremove(va, size); 153 pmap_update(pmap_kernel()); 154 155 uvm_km_free(kernel_map, va, size, UVM_KMF_VAONLY); 156 } 157 158 void * 159 io_mapping_map_atomic_wc(struct io_mapping *mapping, bus_addr_t offset) 160 { 161 paddr_t cookie; 162 163 KASSERT(0 == (offset & (PAGE_SIZE - 1))); 164 KASSERT(PAGE_SIZE <= mapping->size); 165 KASSERT(offset <= (mapping->size - PAGE_SIZE)); 166 KASSERT(__type_fit(off_t, offset)); 167 KASSERT(!mapping->diom_atomic); 168 169 cookie = bus_space_mmap(mapping->diom_bst, mapping->base, offset, 170 PROT_READ|PROT_WRITE, 171 BUS_SPACE_MAP_LINEAR|BUS_SPACE_MAP_PREFETCHABLE); 172 KASSERT(cookie != (paddr_t)-1); 173 174 pmap_kenter_pa(mapping->diom_va, pmap_phys_address(cookie), 175 PROT_READ|PROT_WRITE, pmap_mmap_flags(cookie)); 176 pmap_update(pmap_kernel()); 177 178 mapping->diom_atomic = true; 179 return (void *)mapping->diom_va; 180 } 181 182 void 183 io_mapping_unmap_atomic(struct io_mapping *mapping, void *ptr __diagused) 184 { 185 186 KASSERT(mapping->diom_atomic); 187 KASSERT(mapping->diom_va == (vaddr_t)ptr); 188 189 pmap_kremove(mapping->diom_va, PAGE_SIZE); 190 pmap_update(pmap_kernel()); 191 192 mapping->diom_atomic = false; 193 } 194
Indexes created Sat Sep 20 22:09:52 GMT 2025