1 /* $NetBSD: io-mapping.h,v 1.5 2015/02/25 14:02:43 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 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 #ifndef _LINUX_IO_MAPPING_H_ 33 #define _LINUX_IO_MAPPING_H_ 34 35 #include <sys/param.h> 36 #include <sys/bus.h> 37 #include <sys/kmem.h> 38 #include <sys/systm.h> 39 #include <sys/mman.h> 40 41 #include <uvm/uvm_extern.h> 42 43 struct io_mapping { 44 bus_space_tag_t diom_bst; 45 bus_addr_t diom_addr; 46 bus_size_t diom_size; 47 vaddr_t diom_va; 48 bool diom_mapped; 49 }; 50 51 static inline struct io_mapping * 52 bus_space_io_mapping_create_wc(bus_space_tag_t bst, bus_addr_t addr, 53 bus_size_t size) 54 { 55 struct io_mapping *mapping; 56 bus_size_t offset; 57 58 KASSERT(PAGE_SIZE <= size); 59 KASSERT(0 == (size & (PAGE_SIZE - 1))); 60 KASSERT(__type_fit(off_t, size)); 61 62 /* 63 * XXX For x86: Reserve the region (bus_space_reserve) and set 64 * an MTRR to make it write-combining. Doesn't matter if we 65 * have PAT and we use pmap_kenter_pa, but matters if we don't 66 * have PAT or if we later make this use direct map. 67 */ 68 69 /* Make sure the region is mappable. */ 70 for (offset = 0; offset < size; offset += PAGE_SIZE) { 71 if (bus_space_mmap(bst, addr, offset, PROT_READ|PROT_WRITE, 72 BUS_SPACE_MAP_LINEAR|BUS_SPACE_MAP_PREFETCHABLE) 73 == (paddr_t)-1) 74 return NULL; 75 } 76 77 /* Create a mapping record. */ 78 mapping = kmem_alloc(sizeof(*mapping), KM_SLEEP); 79 mapping->diom_bst = bst; 80 mapping->diom_addr = addr; 81 mapping->diom_size = size; 82 mapping->diom_mapped = false; 83 84 /* Allocate kva for one page. */ 85 mapping->diom_va = uvm_km_alloc(kernel_map, PAGE_SIZE, PAGE_SIZE, 86 UVM_KMF_VAONLY | UVM_KMF_WAITVA); 87 KASSERT(mapping->diom_va != 0); 88 89 return mapping; 90 } 91 92 static inline void 93 io_mapping_free(struct io_mapping *mapping) 94 { 95 96 KASSERT(!mapping->diom_mapped); 97 98 uvm_km_free(kernel_map, mapping->diom_va, PAGE_SIZE, UVM_KMF_VAONLY); 99 kmem_free(mapping, sizeof(*mapping)); 100 } 101 102 static inline void * 103 io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) 104 { 105 paddr_t cookie; 106 107 KASSERT(0 == (offset & (PAGE_SIZE - 1))); 108 KASSERT(PAGE_SIZE <= mapping->diom_size); 109 KASSERT(offset <= (mapping->diom_size - PAGE_SIZE)); 110 KASSERT(__type_fit(off_t, offset)); 111 KASSERT(!mapping->diom_mapped); 112 113 cookie = bus_space_mmap(mapping->diom_bst, mapping->diom_addr, offset, 114 PROT_READ|PROT_WRITE, 115 BUS_SPACE_MAP_LINEAR|BUS_SPACE_MAP_PREFETCHABLE); 116 KASSERT(cookie != (paddr_t)-1); 117 118 pmap_kenter_pa(mapping->diom_va, pmap_phys_address(cookie), 119 PROT_READ|PROT_WRITE, pmap_mmap_flags(cookie)); 120 pmap_update(pmap_kernel()); 121 122 mapping->diom_mapped = true; 123 return (void *)mapping->diom_va; 124 } 125 126 static inline void 127 io_mapping_unmap(struct io_mapping *mapping, void *ptr __diagused) 128 { 129 130 KASSERT(mapping->diom_mapped); 131 KASSERT(mapping->diom_va == (vaddr_t)ptr); 132 133 pmap_kremove(mapping->diom_va, PAGE_SIZE); 134 pmap_update(pmap_kernel()); 135 136 mapping->diom_mapped = false; 137 } 138 139 static inline void * 140 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) 141 { 142 143 return io_mapping_map_wc(mapping, offset); 144 } 145 146 static inline void 147 io_mapping_unmap_atomic(struct io_mapping *mapping, void *ptr) 148 { 149 150 io_mapping_unmap(mapping, ptr); 151 } 152 153 #endif /* _LINUX_IO_MAPPING_H_ */ 154