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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> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
9663f2e6 KP |
23 | #include <asm/io.h> |
24 | #include <asm/page.h> | |
25 | #include <asm/iomap.h> | |
26 | ||
27 | /* | |
28 | * The io_mapping mechanism provides an abstraction for mapping | |
29 | * individual pages from an io device to the CPU in an efficient fashion. | |
30 | * | |
31 | * See Documentation/io_mapping.txt | |
32 | */ | |
33 | ||
e5beae16 KP |
34 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP |
35 | ||
4ab0d47d VP |
36 | struct io_mapping { |
37 | resource_size_t base; | |
38 | unsigned long size; | |
39 | pgprot_t prot; | |
40 | }; | |
41 | ||
e5beae16 KP |
42 | /* |
43 | * For small address space machines, mapping large objects | |
44 | * into the kernel virtual space isn't practical. Where | |
45 | * available, use fixmap support to dynamically map pages | |
46 | * of the object at run time. | |
47 | */ | |
9663f2e6 | 48 | |
9663f2e6 | 49 | static inline struct io_mapping * |
4ab0d47d | 50 | io_mapping_create_wc(resource_size_t base, unsigned long size) |
9663f2e6 | 51 | { |
4ab0d47d | 52 | struct io_mapping *iomap; |
9e36fda0 | 53 | pgprot_t prot; |
4ab0d47d VP |
54 | |
55 | iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); | |
56 | if (!iomap) | |
9e36fda0 VP |
57 | goto out_err; |
58 | ||
59 | if (iomap_create_wc(base, size, &prot)) | |
60 | goto out_free; | |
4ab0d47d VP |
61 | |
62 | iomap->base = base; | |
63 | iomap->size = size; | |
9e36fda0 | 64 | iomap->prot = prot; |
4ab0d47d | 65 | return iomap; |
9e36fda0 VP |
66 | |
67 | out_free: | |
68 | kfree(iomap); | |
69 | out_err: | |
70 | return NULL; | |
9663f2e6 KP |
71 | } |
72 | ||
73 | static inline void | |
74 | io_mapping_free(struct io_mapping *mapping) | |
75 | { | |
9e36fda0 | 76 | iomap_free(mapping->base, mapping->size); |
4ab0d47d | 77 | kfree(mapping); |
9663f2e6 KP |
78 | } |
79 | ||
80 | /* Atomic map/unmap */ | |
81 | static inline void * | |
82 | io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) | |
83 | { | |
4ab0d47d VP |
84 | resource_size_t phys_addr; |
85 | unsigned long pfn; | |
86 | ||
87 | BUG_ON(offset >= mapping->size); | |
88 | phys_addr = mapping->base + offset; | |
89 | pfn = (unsigned long) (phys_addr >> PAGE_SHIFT); | |
90 | return iomap_atomic_prot_pfn(pfn, KM_USER0, mapping->prot); | |
9663f2e6 KP |
91 | } |
92 | ||
93 | static inline void | |
94 | io_mapping_unmap_atomic(void *vaddr) | |
95 | { | |
e5beae16 | 96 | iounmap_atomic(vaddr, KM_USER0); |
9663f2e6 KP |
97 | } |
98 | ||
9663f2e6 KP |
99 | static inline void * |
100 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) | |
101 | { | |
5ce04e3d PV |
102 | resource_size_t phys_addr; |
103 | ||
4ab0d47d | 104 | BUG_ON(offset >= mapping->size); |
5ce04e3d PV |
105 | phys_addr = mapping->base + offset; |
106 | ||
4ab0d47d | 107 | return ioremap_wc(phys_addr, PAGE_SIZE); |
9663f2e6 KP |
108 | } |
109 | ||
110 | static inline void | |
111 | io_mapping_unmap(void *vaddr) | |
112 | { | |
e5beae16 | 113 | iounmap(vaddr); |
9663f2e6 KP |
114 | } |
115 | ||
e5beae16 | 116 | #else |
9663f2e6 | 117 | |
4ab0d47d VP |
118 | /* this struct isn't actually defined anywhere */ |
119 | struct io_mapping; | |
120 | ||
e5beae16 | 121 | /* Create the io_mapping object*/ |
9663f2e6 | 122 | static inline struct io_mapping * |
4ab0d47d | 123 | io_mapping_create_wc(resource_size_t base, unsigned long size) |
9663f2e6 | 124 | { |
e5beae16 | 125 | return (struct io_mapping *) ioremap_wc(base, size); |
9663f2e6 KP |
126 | } |
127 | ||
128 | static inline void | |
129 | io_mapping_free(struct io_mapping *mapping) | |
130 | { | |
e5beae16 | 131 | iounmap(mapping); |
9663f2e6 KP |
132 | } |
133 | ||
134 | /* Atomic map/unmap */ | |
135 | static inline void * | |
136 | io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) | |
137 | { | |
e5beae16 | 138 | return ((char *) mapping) + offset; |
9663f2e6 KP |
139 | } |
140 | ||
141 | static inline void | |
142 | io_mapping_unmap_atomic(void *vaddr) | |
143 | { | |
9663f2e6 KP |
144 | } |
145 | ||
e5beae16 | 146 | /* Non-atomic map/unmap */ |
9663f2e6 KP |
147 | static inline void * |
148 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) | |
149 | { | |
e5beae16 | 150 | return ((char *) mapping) + offset; |
9663f2e6 KP |
151 | } |
152 | ||
153 | static inline void | |
154 | io_mapping_unmap(void *vaddr) | |
155 | { | |
9663f2e6 | 156 | } |
e5beae16 KP |
157 | |
158 | #endif /* HAVE_ATOMIC_IOMAP */ | |
9663f2e6 KP |
159 | |
160 | #endif /* _LINUX_IO_MAPPING_H */ |