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9663f2e6 KP |
1 | /* |
2 | * Copyright © 2008 Keith Packard <keithp@keithp.com> | |
3 | * | |
4 | * This file is free software; you can redistribute it and/or modify | |
5 | * it under the terms of version 2 of the GNU General Public License | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write to the Free Software Foundation, | |
15 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. | |
16 | */ | |
17 | ||
18 | #ifndef _LINUX_IO_MAPPING_H | |
19 | #define _LINUX_IO_MAPPING_H | |
20 | ||
21 | #include <linux/types.h> | |
22 | #include <asm/io.h> | |
23 | #include <asm/page.h> | |
24 | #include <asm/iomap.h> | |
25 | ||
26 | /* | |
27 | * The io_mapping mechanism provides an abstraction for mapping | |
28 | * individual pages from an io device to the CPU in an efficient fashion. | |
29 | * | |
30 | * See Documentation/io_mapping.txt | |
31 | */ | |
32 | ||
e5beae16 KP |
33 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP |
34 | ||
4ab0d47d VP |
35 | struct io_mapping { |
36 | resource_size_t base; | |
37 | unsigned long size; | |
38 | pgprot_t prot; | |
39 | }; | |
40 | ||
e5beae16 KP |
41 | /* |
42 | * For small address space machines, mapping large objects | |
43 | * into the kernel virtual space isn't practical. Where | |
44 | * available, use fixmap support to dynamically map pages | |
45 | * of the object at run time. | |
46 | */ | |
9663f2e6 | 47 | |
9663f2e6 | 48 | static inline struct io_mapping * |
4ab0d47d | 49 | io_mapping_create_wc(resource_size_t base, unsigned long size) |
9663f2e6 | 50 | { |
4ab0d47d VP |
51 | struct io_mapping *iomap; |
52 | ||
53 | if (!is_io_mapping_possible(base, size)) | |
54 | return NULL; | |
55 | ||
56 | iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); | |
57 | if (!iomap) | |
58 | return NULL; | |
59 | ||
60 | iomap->base = base; | |
61 | iomap->size = size; | |
62 | iomap->prot = pgprot_writecombine(__pgprot(__PAGE_KERNEL)); | |
63 | return iomap; | |
9663f2e6 KP |
64 | } |
65 | ||
66 | static inline void | |
67 | io_mapping_free(struct io_mapping *mapping) | |
68 | { | |
4ab0d47d | 69 | kfree(mapping); |
9663f2e6 KP |
70 | } |
71 | ||
72 | /* Atomic map/unmap */ | |
73 | static inline void * | |
74 | io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) | |
75 | { | |
4ab0d47d VP |
76 | resource_size_t phys_addr; |
77 | unsigned long pfn; | |
78 | ||
79 | BUG_ON(offset >= mapping->size); | |
80 | phys_addr = mapping->base + offset; | |
81 | pfn = (unsigned long) (phys_addr >> PAGE_SHIFT); | |
82 | return iomap_atomic_prot_pfn(pfn, KM_USER0, mapping->prot); | |
9663f2e6 KP |
83 | } |
84 | ||
85 | static inline void | |
86 | io_mapping_unmap_atomic(void *vaddr) | |
87 | { | |
e5beae16 | 88 | iounmap_atomic(vaddr, KM_USER0); |
9663f2e6 KP |
89 | } |
90 | ||
9663f2e6 KP |
91 | static inline void * |
92 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) | |
93 | { | |
5ce04e3d PV |
94 | resource_size_t phys_addr; |
95 | ||
4ab0d47d | 96 | BUG_ON(offset >= mapping->size); |
5ce04e3d PV |
97 | phys_addr = mapping->base + offset; |
98 | ||
4ab0d47d | 99 | return ioremap_wc(phys_addr, PAGE_SIZE); |
9663f2e6 KP |
100 | } |
101 | ||
102 | static inline void | |
103 | io_mapping_unmap(void *vaddr) | |
104 | { | |
e5beae16 | 105 | iounmap(vaddr); |
9663f2e6 KP |
106 | } |
107 | ||
e5beae16 | 108 | #else |
9663f2e6 | 109 | |
4ab0d47d VP |
110 | /* this struct isn't actually defined anywhere */ |
111 | struct io_mapping; | |
112 | ||
e5beae16 | 113 | /* Create the io_mapping object*/ |
9663f2e6 | 114 | static inline struct io_mapping * |
4ab0d47d | 115 | io_mapping_create_wc(resource_size_t base, unsigned long size) |
9663f2e6 | 116 | { |
e5beae16 | 117 | return (struct io_mapping *) ioremap_wc(base, size); |
9663f2e6 KP |
118 | } |
119 | ||
120 | static inline void | |
121 | io_mapping_free(struct io_mapping *mapping) | |
122 | { | |
e5beae16 | 123 | iounmap(mapping); |
9663f2e6 KP |
124 | } |
125 | ||
126 | /* Atomic map/unmap */ | |
127 | static inline void * | |
128 | io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) | |
129 | { | |
e5beae16 | 130 | return ((char *) mapping) + offset; |
9663f2e6 KP |
131 | } |
132 | ||
133 | static inline void | |
134 | io_mapping_unmap_atomic(void *vaddr) | |
135 | { | |
9663f2e6 KP |
136 | } |
137 | ||
e5beae16 | 138 | /* Non-atomic map/unmap */ |
9663f2e6 KP |
139 | static inline void * |
140 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) | |
141 | { | |
e5beae16 | 142 | return ((char *) mapping) + offset; |
9663f2e6 KP |
143 | } |
144 | ||
145 | static inline void | |
146 | io_mapping_unmap(void *vaddr) | |
147 | { | |
9663f2e6 | 148 | } |
e5beae16 KP |
149 | |
150 | #endif /* HAVE_ATOMIC_IOMAP */ | |
9663f2e6 KP |
151 | |
152 | #endif /* _LINUX_IO_MAPPING_H */ |