xref: /openbmc/linux/include/linux/io.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Copyright 2006 PathScale, Inc.  All Rights Reserved.
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_H
19 #define _LINUX_IO_H
20 
21 #include <linux/types.h>
22 #include <linux/init.h>
23 #include <linux/bug.h>
24 #include <linux/err.h>
25 #include <asm/io.h>
26 #include <asm/page.h>
27 
28 struct device;
29 struct resource;
30 
31 __visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
32 void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
33 
34 #ifdef CONFIG_MMU
35 int ioremap_page_range(unsigned long addr, unsigned long end,
36 		       phys_addr_t phys_addr, pgprot_t prot);
37 #else
38 static inline int ioremap_page_range(unsigned long addr, unsigned long end,
39 				     phys_addr_t phys_addr, pgprot_t prot)
40 {
41 	return 0;
42 }
43 #endif
44 
45 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
46 void __init ioremap_huge_init(void);
47 int arch_ioremap_pud_supported(void);
48 int arch_ioremap_pmd_supported(void);
49 #else
50 static inline void ioremap_huge_init(void) { }
51 #endif
52 
53 /*
54  * Managed iomap interface
55  */
56 #ifdef CONFIG_HAS_IOPORT_MAP
57 void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
58 			       unsigned int nr);
59 void devm_ioport_unmap(struct device *dev, void __iomem *addr);
60 #else
61 static inline void __iomem *devm_ioport_map(struct device *dev,
62 					     unsigned long port,
63 					     unsigned int nr)
64 {
65 	return NULL;
66 }
67 
68 static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
69 {
70 }
71 #endif
72 
73 #define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
74 
75 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
76 			   resource_size_t size);
77 void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
78 				   resource_size_t size);
79 void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
80 				   resource_size_t size);
81 void devm_iounmap(struct device *dev, void __iomem *addr);
82 int check_signature(const volatile void __iomem *io_addr,
83 			const unsigned char *signature, int length);
84 void devm_ioremap_release(struct device *dev, void *res);
85 
86 void *devm_memremap(struct device *dev, resource_size_t offset,
87 		size_t size, unsigned long flags);
88 void devm_memunmap(struct device *dev, void *addr);
89 
90 void *__devm_memremap_pages(struct device *dev, struct resource *res);
91 
92 #ifdef CONFIG_ZONE_DEVICE
93 void *devm_memremap_pages(struct device *dev, struct resource *res);
94 #else
95 static inline void *devm_memremap_pages(struct device *dev, struct resource *res)
96 {
97 	/*
98 	 * Fail attempts to call devm_memremap_pages() without
99 	 * ZONE_DEVICE support enabled, this requires callers to fall
100 	 * back to plain devm_memremap() based on config
101 	 */
102 	WARN_ON_ONCE(1);
103 	return ERR_PTR(-ENXIO);
104 }
105 #endif
106 
107 /*
108  * Some systems do not have legacy ISA devices.
109  * /dev/port is not a valid interface on these systems.
110  * So for those archs, <asm/io.h> should define the following symbol.
111  */
112 #ifndef arch_has_dev_port
113 #define arch_has_dev_port()     (1)
114 #endif
115 
116 /*
117  * Some systems (x86 without PAT) have a somewhat reliable way to mark a
118  * physical address range such that uncached mappings will actually
119  * end up write-combining.  This facility should be used in conjunction
120  * with pgprot_writecombine, ioremap-wc, or set_memory_wc, since it has
121  * no effect if the per-page mechanisms are functional.
122  * (On x86 without PAT, these functions manipulate MTRRs.)
123  *
124  * arch_phys_del_wc(0) or arch_phys_del_wc(any error code) is guaranteed
125  * to have no effect.
126  */
127 #ifndef arch_phys_wc_add
128 static inline int __must_check arch_phys_wc_add(unsigned long base,
129 						unsigned long size)
130 {
131 	return 0;  /* It worked (i.e. did nothing). */
132 }
133 
134 static inline void arch_phys_wc_del(int handle)
135 {
136 }
137 
138 #define arch_phys_wc_add arch_phys_wc_add
139 #ifndef arch_phys_wc_index
140 static inline int arch_phys_wc_index(int handle)
141 {
142 	return -1;
143 }
144 #define arch_phys_wc_index arch_phys_wc_index
145 #endif
146 #endif
147 
148 enum {
149 	/* See memremap() kernel-doc for usage description... */
150 	MEMREMAP_WB = 1 << 0,
151 	MEMREMAP_WT = 1 << 1,
152 };
153 
154 void *memremap(resource_size_t offset, size_t size, unsigned long flags);
155 void memunmap(void *addr);
156 
157 #endif /* _LINUX_IO_H */
158