2 * Copyright © 2008 Keith Packard <keithp@keithp.com>
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.
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.
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.
18 #ifndef _LINUX_IO_MAPPING_H
19 #define _LINUX_IO_MAPPING_H
21 #include <linux/types.h>
22 #include <linux/slab.h>
23 #include <linux/bug.h>
28 * The io_mapping mechanism provides an abstraction for mapping
29 * individual pages from an io device to the CPU in an efficient fashion.
31 * See Documentation/io-mapping.txt
34 #ifdef CONFIG_HAVE_ATOMIC_IOMAP
36 #include <asm/iomap.h>
45 * For small address space machines, mapping large objects
46 * into the kernel virtual space isn't practical. Where
47 * available, use fixmap support to dynamically map pages
48 * of the object at run time.
51 static inline struct io_mapping
*
52 io_mapping_create_wc(resource_size_t base
, unsigned long size
)
54 struct io_mapping
*iomap
;
57 iomap
= kmalloc(sizeof(*iomap
), GFP_KERNEL
);
61 if (iomap_create_wc(base
, size
, &prot
))
76 io_mapping_free(struct io_mapping
*mapping
)
78 iomap_free(mapping
->base
, mapping
->size
);
82 /* Atomic map/unmap */
83 static inline void __iomem
*
84 io_mapping_map_atomic_wc(struct io_mapping
*mapping
,
87 resource_size_t phys_addr
;
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
, mapping
->prot
);
97 io_mapping_unmap_atomic(void __iomem
*vaddr
)
99 iounmap_atomic(vaddr
);
102 static inline void __iomem
*
103 io_mapping_map_wc(struct io_mapping
*mapping
, unsigned long offset
)
105 resource_size_t phys_addr
;
107 BUG_ON(offset
>= mapping
->size
);
108 phys_addr
= mapping
->base
+ offset
;
110 return ioremap_wc(phys_addr
, PAGE_SIZE
);
114 io_mapping_unmap(void __iomem
*vaddr
)
121 #include <linux/uaccess.h>
123 /* this struct isn't actually defined anywhere */
126 /* Create the io_mapping object*/
127 static inline struct io_mapping
*
128 io_mapping_create_wc(resource_size_t base
, unsigned long size
)
130 return (struct io_mapping __force
*) ioremap_wc(base
, size
);
134 io_mapping_free(struct io_mapping
*mapping
)
136 iounmap((void __force __iomem
*) mapping
);
139 /* Atomic map/unmap */
140 static inline void __iomem
*
141 io_mapping_map_atomic_wc(struct io_mapping
*mapping
,
142 unsigned long offset
)
145 return ((char __force __iomem
*) mapping
) + offset
;
149 io_mapping_unmap_atomic(void __iomem
*vaddr
)
154 /* Non-atomic map/unmap */
155 static inline void __iomem
*
156 io_mapping_map_wc(struct io_mapping
*mapping
, unsigned long offset
)
158 return ((char __force __iomem
*) mapping
) + offset
;
162 io_mapping_unmap(void __iomem
*vaddr
)
166 #endif /* HAVE_ATOMIC_IOMAP */
168 #endif /* _LINUX_IO_MAPPING_H */