xref: /netbsd-src/sys/external/bsd/drm2/include/linux/io-mapping.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: io-mapping.h,v 1.2 2014/03/18 18:20:43 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Taylor R. Campbell.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _LINUX_IO_MAPPING_H_
33 #define _LINUX_IO_MAPPING_H_
34 
35 #include <sys/bus.h>
36 #include <sys/kmem.h>
37 #include <sys/systm.h>
38 
39 struct io_mapping {
40 	bus_space_tag_t		diom_bst;
41 	bus_addr_t		diom_addr;
42 	bus_size_t		diom_size;
43 	int			diom_flags;
44 	bus_space_handle_t	diom_bsh;
45 	void			*diom_vaddr;
46 };
47 
48 static inline struct io_mapping *
49 bus_space_io_mapping_create_wc(bus_space_tag_t bst, bus_addr_t addr,
50     bus_size_t size)
51 {
52 	struct io_mapping *const mapping = kmem_alloc(sizeof(*mapping),
53 	    KM_SLEEP);
54 	mapping->diom_bst = bst;
55 	mapping->diom_addr = addr;
56 	mapping->diom_size = size;
57 	mapping->diom_flags = 0;
58 	mapping->diom_flags |= BUS_SPACE_MAP_LINEAR;
59 	mapping->diom_flags |= BUS_SPACE_MAP_PREFETCHABLE;
60 	mapping->diom_vaddr = NULL;
61 
62 	bus_space_handle_t bsh;
63 	if (bus_space_map(mapping->diom_bst, addr, PAGE_SIZE,
64 		mapping->diom_flags, &bsh)) {
65 		kmem_free(mapping, sizeof(*mapping));
66 		return NULL;
67 	}
68 	bus_space_unmap(mapping->diom_bst, bsh, PAGE_SIZE);
69 
70 	return mapping;
71 }
72 
73 static inline void
74 io_mapping_free(struct io_mapping *mapping)
75 {
76 
77 	KASSERT(mapping->diom_vaddr == NULL);
78 	kmem_free(mapping, sizeof(*mapping));
79 }
80 
81 static inline void *
82 io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
83 {
84 
85 	KASSERT(mapping->diom_vaddr == NULL);
86 	KASSERT(ISSET(mapping->diom_flags, BUS_SPACE_MAP_LINEAR));
87 	if (bus_space_map(mapping->diom_bst, (mapping->diom_addr + offset),
88 		PAGE_SIZE, mapping->diom_flags, &mapping->diom_bsh))
89 		panic("Unable to make I/O mapping!"); /* XXX */
90 	mapping->diom_vaddr = bus_space_vaddr(mapping->diom_bst,
91 	    mapping->diom_bsh);
92 
93 	return mapping->diom_vaddr;
94 }
95 
96 static inline void
97 io_mapping_unmap(struct io_mapping *mapping, void *vaddr __unused)
98 {
99 
100 	KASSERT(mapping->diom_vaddr == vaddr);
101 	bus_space_unmap(mapping->diom_bst, mapping->diom_bsh, PAGE_SIZE);
102 	mapping->diom_vaddr = NULL;
103 }
104 
105 static inline void *
106 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset)
107 {
108 	return io_mapping_map_wc(mapping, offset);
109 }
110 
111 static inline void
112 io_mapping_unmap_atomic(struct io_mapping *mapping, void *vaddr __unused)
113 {
114 	return io_mapping_unmap(mapping, vaddr);
115 }
116 
117 #endif  /* _LINUX_IO_MAPPING_H_ */
118