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 *
bus_space_io_mapping_create_wc(bus_space_tag_t bst,bus_addr_t addr,bus_size_t size)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
io_mapping_free(struct io_mapping * mapping)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 *
io_mapping_map_wc(struct io_mapping * mapping,unsigned long offset)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
io_mapping_unmap(struct io_mapping * mapping,void * ptr __diagused)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 *
io_mapping_map_atomic_wc(struct io_mapping * mapping,unsigned long offset)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
io_mapping_unmap_atomic(struct io_mapping * mapping,void * ptr)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