1 /*
2 * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #ifndef _LINUX_IOMAPPING_H_
28 #define _LINUX_IOMAPPING_H_
29
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/bug.h>
33 #include <linux/io.h>
34 #include <asm/page.h>
35
36 #include <asm/iomap.h>
37
38 struct io_mapping {
39 resource_size_t base;
40 unsigned long size;
41 unsigned long prot;
42 void *vaddr;
43 };
44
45 static inline struct io_mapping *
io_mapping_create_wc(resource_size_t base,unsigned long size)46 io_mapping_create_wc(resource_size_t base, unsigned long size)
47 {
48 struct io_mapping *map;
49
50 map = kmalloc(sizeof(struct io_mapping), M_DRM, M_WAITOK);
51 map->base = base;
52 map->size = size;
53 map->prot = VM_MEMATTR_WRITE_COMBINING;
54
55 map->vaddr = pmap_mapdev_attr(base, size,
56 VM_MEMATTR_WRITE_COMBINING);
57 if (map->vaddr == NULL)
58 return NULL;
59
60 return map;
61 }
62
io_mapping_free(struct io_mapping * mapping)63 static inline void io_mapping_free(struct io_mapping *mapping)
64 {
65 /* Default memory attribute is write-back */
66 pmap_mapdev_attr(mapping->base, mapping->size, VM_MEMATTR_WRITE_BACK);
67 kfree(mapping);
68 }
69
70 static inline void *
io_mapping_map_wc(struct io_mapping * mapping,unsigned long offset,unsigned long size)71 io_mapping_map_wc(struct io_mapping *mapping,
72 unsigned long offset,
73 unsigned long size)
74 {
75 BUG_ON(offset >= mapping->size);
76
77 return ioremap_wc(mapping->base + offset, size);
78 }
79
80 static inline void *
io_mapping_map_atomic_wc(struct io_mapping * mapping,unsigned long offset)81 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset)
82 {
83 return ioremap_wc(mapping->base + offset, PAGE_SIZE);
84 }
85
86 static inline void
io_mapping_unmap(void * vaddr)87 io_mapping_unmap(void *vaddr)
88 {
89 iounmap(vaddr);
90 }
91
92 static inline void
io_mapping_unmap_atomic(void * vaddr)93 io_mapping_unmap_atomic(void *vaddr)
94 {
95 iounmap(vaddr);
96 }
97
98 static inline struct io_mapping *
io_mapping_init_wc(struct io_mapping * iomap,resource_size_t base,unsigned long size)99 io_mapping_init_wc(struct io_mapping *iomap,
100 resource_size_t base,
101 unsigned long size)
102 {
103 iomap->base = base;
104 iomap->size = size;
105 iomap->vaddr = ioremap_wc(base, size);
106 iomap->prot = pgprot_writecombine(PAGE_KERNEL_IO);
107
108 return iomap;
109 }
110
111 static inline void
io_mapping_fini(struct io_mapping * mapping)112 io_mapping_fini(struct io_mapping *mapping)
113 {
114 iounmap(mapping->vaddr);
115 }
116
117 #endif /* _LINUX_IOMAPPING_H_ */
118