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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 <linux/slab.h> | |
23 | #include <asm/io.h> | |
24 | #include <asm/page.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 | ||
33 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP | |
34 | ||
35 | #include <asm/iomap.h> | |
36 | ||
37 | struct io_mapping { | |
38 | resource_size_t base; | |
39 | unsigned long size; | |
40 | pgprot_t prot; | |
41 | }; | |
42 | ||
43 | /* | |
44 | * For small address space machines, mapping large objects | |
45 | * into the kernel virtual space isn't practical. Where | |
46 | * available, use fixmap support to dynamically map pages | |
47 | * of the object at run time. | |
48 | */ | |
49 | ||
50 | static inline struct io_mapping * | |
51 | io_mapping_create_wc(resource_size_t base, unsigned long size) | |
52 | { | |
53 | struct io_mapping *iomap; | |
54 | pgprot_t prot; | |
55 | ||
56 | iomap = kmalloc(sizeof(*iomap), GFP_KERNEL); | |
57 | if (!iomap) | |
58 | goto out_err; | |
59 | ||
60 | if (iomap_create_wc(base, size, &prot)) | |
61 | goto out_free; | |
62 | ||
63 | iomap->base = base; | |
64 | iomap->size = size; | |
65 | iomap->prot = prot; | |
66 | return iomap; | |
67 | ||
68 | out_free: | |
69 | kfree(iomap); | |
70 | out_err: | |
71 | return NULL; | |
72 | } | |
73 | ||
74 | static inline void | |
75 | io_mapping_free(struct io_mapping *mapping) | |
76 | { | |
77 | iomap_free(mapping->base, mapping->size); | |
78 | kfree(mapping); | |
79 | } | |
80 | ||
81 | /* Atomic map/unmap */ | |
82 | static inline void __iomem * | |
83 | io_mapping_map_atomic_wc(struct io_mapping *mapping, | |
84 | unsigned long offset, | |
85 | int slot) | |
86 | { | |
87 | resource_size_t phys_addr; | |
88 | unsigned long pfn; | |
89 | ||
90 | BUG_ON(offset >= mapping->size); | |
91 | phys_addr = mapping->base + offset; | |
92 | pfn = (unsigned long) (phys_addr >> PAGE_SHIFT); | |
93 | return iomap_atomic_prot_pfn(pfn, slot, mapping->prot); | |
94 | } | |
95 | ||
96 | static inline void | |
97 | io_mapping_unmap_atomic(void __iomem *vaddr, int slot) | |
98 | { | |
99 | iounmap_atomic(vaddr, slot); | |
100 | } | |
101 | ||
102 | static inline void __iomem * | |
103 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) | |
104 | { | |
105 | resource_size_t phys_addr; | |
106 | ||
107 | BUG_ON(offset >= mapping->size); | |
108 | phys_addr = mapping->base + offset; | |
109 | ||
110 | return ioremap_wc(phys_addr, PAGE_SIZE); | |
111 | } | |
112 | ||
113 | static inline void | |
114 | io_mapping_unmap(void __iomem *vaddr) | |
115 | { | |
116 | iounmap(vaddr); | |
117 | } | |
118 | ||
119 | #else | |
120 | ||
121 | /* this struct isn't actually defined anywhere */ | |
122 | struct io_mapping; | |
123 | ||
124 | /* Create the io_mapping object*/ | |
125 | static inline struct io_mapping * | |
126 | io_mapping_create_wc(resource_size_t base, unsigned long size) | |
127 | { | |
128 | return (struct io_mapping __force *) ioremap_wc(base, size); | |
129 | } | |
130 | ||
131 | static inline void | |
132 | io_mapping_free(struct io_mapping *mapping) | |
133 | { | |
134 | iounmap((void __force __iomem *) mapping); | |
135 | } | |
136 | ||
137 | /* Atomic map/unmap */ | |
138 | static inline void __iomem * | |
139 | io_mapping_map_atomic_wc(struct io_mapping *mapping, | |
140 | unsigned long offset, | |
141 | int slot) | |
142 | { | |
143 | return ((char __force __iomem *) mapping) + offset; | |
144 | } | |
145 | ||
146 | static inline void | |
147 | io_mapping_unmap_atomic(void __iomem *vaddr, int slot) | |
148 | { | |
149 | } | |
150 | ||
151 | /* Non-atomic map/unmap */ | |
152 | static inline void __iomem * | |
153 | io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset) | |
154 | { | |
155 | return ((char __force __iomem *) mapping) + offset; | |
156 | } | |
157 | ||
158 | static inline void | |
159 | io_mapping_unmap(void __iomem *vaddr) | |
160 | { | |
161 | } | |
162 | ||
163 | #endif /* HAVE_ATOMIC_IOMAP */ | |
164 | ||
165 | #endif /* _LINUX_IO_MAPPING_H */ |