xref: /linux-6.15/include/linux/io.h (revision dee3d0be)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2006 PathScale, Inc.  All Rights Reserved.
4  */
5 
6 #ifndef _LINUX_IO_H
7 #define _LINUX_IO_H
8 
9 #include <linux/sizes.h>
10 #include <linux/types.h>
11 #include <linux/init.h>
12 #include <linux/bug.h>
13 #include <linux/err.h>
14 #include <asm/io.h>
15 #include <asm/page.h>
16 
17 struct device;
18 struct resource;
19 
20 __visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
21 void __ioread32_copy(void *to, const void __iomem *from, size_t count);
22 void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
23 
24 #ifdef CONFIG_MMU
25 int ioremap_page_range(unsigned long addr, unsigned long end,
26 		       phys_addr_t phys_addr, pgprot_t prot);
27 int vmap_page_range(unsigned long addr, unsigned long end,
28 		    phys_addr_t phys_addr, pgprot_t prot);
29 #else
30 static inline int ioremap_page_range(unsigned long addr, unsigned long end,
31 				     phys_addr_t phys_addr, pgprot_t prot)
32 {
33 	return 0;
34 }
35 static inline int vmap_page_range(unsigned long addr, unsigned long end,
36 				  phys_addr_t phys_addr, pgprot_t prot)
37 {
38 	return 0;
39 }
40 #endif
41 
42 /*
43  * Managed iomap interface
44  */
45 #ifdef CONFIG_HAS_IOPORT_MAP
46 void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
47 			       unsigned int nr);
48 void devm_ioport_unmap(struct device *dev, void __iomem *addr);
49 #else
50 static inline void __iomem *devm_ioport_map(struct device *dev,
51 					     unsigned long port,
52 					     unsigned int nr)
53 {
54 	return NULL;
55 }
56 
57 static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
58 {
59 }
60 #endif
61 
62 #define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
63 
64 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
65 			   resource_size_t size);
66 void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
67 				   resource_size_t size);
68 void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
69 				   resource_size_t size);
70 void devm_iounmap(struct device *dev, void __iomem *addr);
71 int check_signature(const volatile void __iomem *io_addr,
72 			const unsigned char *signature, int length);
73 void devm_ioremap_release(struct device *dev, void *res);
74 
75 void *devm_memremap(struct device *dev, resource_size_t offset,
76 		size_t size, unsigned long flags);
77 void devm_memunmap(struct device *dev, void *addr);
78 
79 /* architectures can override this */
80 pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
81 					unsigned long size, pgprot_t prot);
82 
83 
84 #ifdef CONFIG_PCI
85 /*
86  * The PCI specifications (Rev 3.0, 3.2.5 "Transaction Ordering and
87  * Posting") mandate non-posted configuration transactions. This default
88  * implementation attempts to use the ioremap_np() API to provide this
89  * on arches that support it, and falls back to ioremap() on those that
90  * don't. Overriding this function is deprecated; arches that properly
91  * support non-posted accesses should implement ioremap_np() instead, which
92  * this default implementation can then use to return mappings compliant with
93  * the PCI specification.
94  */
95 #ifndef pci_remap_cfgspace
96 #define pci_remap_cfgspace pci_remap_cfgspace
97 static inline void __iomem *pci_remap_cfgspace(phys_addr_t offset,
98 					       size_t size)
99 {
100 	return ioremap_np(offset, size) ?: ioremap(offset, size);
101 }
102 #endif
103 #endif
104 
105 /*
106  * Some systems do not have legacy ISA devices.
107  * /dev/port is not a valid interface on these systems.
108  * So for those archs, <asm/io.h> should define the following symbol.
109  */
110 #ifndef arch_has_dev_port
111 #define arch_has_dev_port()     (1)
112 #endif
113 
114 /*
115  * Some systems (x86 without PAT) have a somewhat reliable way to mark a
116  * physical address range such that uncached mappings will actually
117  * end up write-combining.  This facility should be used in conjunction
118  * with pgprot_writecombine, ioremap-wc, or set_memory_wc, since it has
119  * no effect if the per-page mechanisms are functional.
120  * (On x86 without PAT, these functions manipulate MTRRs.)
121  *
122  * arch_phys_del_wc(0) or arch_phys_del_wc(any error code) is guaranteed
123  * to have no effect.
124  */
125 #ifndef arch_phys_wc_add
126 static inline int __must_check arch_phys_wc_add(unsigned long base,
127 						unsigned long size)
128 {
129 	return 0;  /* It worked (i.e. did nothing). */
130 }
131 
132 static inline void arch_phys_wc_del(int handle)
133 {
134 }
135 
136 #define arch_phys_wc_add arch_phys_wc_add
137 #ifndef arch_phys_wc_index
138 static inline int arch_phys_wc_index(int handle)
139 {
140 	return -1;
141 }
142 #define arch_phys_wc_index arch_phys_wc_index
143 #endif
144 #endif
145 
146 int devm_arch_phys_wc_add(struct device *dev, unsigned long base, unsigned long size);
147 
148 enum {
149 	/* See memremap() kernel-doc for usage description... */
150 	MEMREMAP_WB = 1 << 0,
151 	MEMREMAP_WT = 1 << 1,
152 	MEMREMAP_WC = 1 << 2,
153 	MEMREMAP_ENC = 1 << 3,
154 	MEMREMAP_DEC = 1 << 4,
155 };
156 
157 void *memremap(resource_size_t offset, size_t size, unsigned long flags);
158 void memunmap(void *addr);
159 
160 /*
161  * On x86 PAT systems we have memory tracking that keeps track of
162  * the allowed mappings on memory ranges. This tracking works for
163  * all the in-kernel mapping APIs (ioremap*), but where the user
164  * wishes to map a range from a physical device into user memory
165  * the tracking won't be updated. This API is to be used by
166  * drivers which remap physical device pages into userspace,
167  * and wants to make sure they are mapped WC and not UC.
168  */
169 #ifndef arch_io_reserve_memtype_wc
170 static inline int arch_io_reserve_memtype_wc(resource_size_t base,
171 					     resource_size_t size)
172 {
173 	return 0;
174 }
175 
176 static inline void arch_io_free_memtype_wc(resource_size_t base,
177 					   resource_size_t size)
178 {
179 }
180 #endif
181 
182 int devm_arch_io_reserve_memtype_wc(struct device *dev, resource_size_t start,
183 				    resource_size_t size);
184 
185 #endif /* _LINUX_IO_H */
186