1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Implement the default iomap interfaces |
4 | * |
5 | * (C) Copyright 2004 Linus Torvalds |
6 | */ |
7 | #include <linux/pci.h> |
8 | #include <linux/io.h> |
9 | |
10 | #include <linux/export.h> |
11 | |
12 | #ifdef CONFIG_PCI |
13 | /** |
14 | * pci_iomap_range - create a virtual mapping cookie for a PCI BAR |
15 | * @dev: PCI device that owns the BAR |
16 | * @bar: BAR number |
17 | * @offset: map memory at the given offset in BAR |
18 | * @maxlen: max length of the memory to map |
19 | * |
20 | * Using this function you will get a __iomem address to your device BAR. |
21 | * You can access it using ioread*() and iowrite*(). These functions hide |
22 | * the details if this is a MMIO or PIO address space and will just do what |
23 | * you expect from them in the correct way. |
24 | * |
25 | * @maxlen specifies the maximum length to map. If you want to get access to |
26 | * the complete BAR from offset to the end, pass %0 here. |
27 | * */ |
28 | void __iomem *pci_iomap_range(struct pci_dev *dev, |
29 | int bar, |
30 | unsigned long offset, |
31 | unsigned long maxlen) |
32 | { |
33 | resource_size_t start = pci_resource_start(dev, bar); |
34 | resource_size_t len = pci_resource_len(dev, bar); |
35 | unsigned long flags = pci_resource_flags(dev, bar); |
36 | |
37 | if (len <= offset || !start) |
38 | return NULL; |
39 | len -= offset; |
40 | start += offset; |
41 | if (maxlen && len > maxlen) |
42 | len = maxlen; |
43 | if (flags & IORESOURCE_IO) |
44 | return __pci_ioport_map(dev, start, len); |
45 | if (flags & IORESOURCE_MEM) |
46 | return ioremap(offset: start, size: len); |
47 | /* What? */ |
48 | return NULL; |
49 | } |
50 | EXPORT_SYMBOL(pci_iomap_range); |
51 | |
52 | /** |
53 | * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR |
54 | * @dev: PCI device that owns the BAR |
55 | * @bar: BAR number |
56 | * @offset: map memory at the given offset in BAR |
57 | * @maxlen: max length of the memory to map |
58 | * |
59 | * Using this function you will get a __iomem address to your device BAR. |
60 | * You can access it using ioread*() and iowrite*(). These functions hide |
61 | * the details if this is a MMIO or PIO address space and will just do what |
62 | * you expect from them in the correct way. When possible write combining |
63 | * is used. |
64 | * |
65 | * @maxlen specifies the maximum length to map. If you want to get access to |
66 | * the complete BAR from offset to the end, pass %0 here. |
67 | * */ |
68 | void __iomem *pci_iomap_wc_range(struct pci_dev *dev, |
69 | int bar, |
70 | unsigned long offset, |
71 | unsigned long maxlen) |
72 | { |
73 | resource_size_t start = pci_resource_start(dev, bar); |
74 | resource_size_t len = pci_resource_len(dev, bar); |
75 | unsigned long flags = pci_resource_flags(dev, bar); |
76 | |
77 | |
78 | if (flags & IORESOURCE_IO) |
79 | return NULL; |
80 | |
81 | if (len <= offset || !start) |
82 | return NULL; |
83 | |
84 | len -= offset; |
85 | start += offset; |
86 | if (maxlen && len > maxlen) |
87 | len = maxlen; |
88 | |
89 | if (flags & IORESOURCE_MEM) |
90 | return ioremap_wc(offset: start, size: len); |
91 | |
92 | /* What? */ |
93 | return NULL; |
94 | } |
95 | EXPORT_SYMBOL_GPL(pci_iomap_wc_range); |
96 | |
97 | /** |
98 | * pci_iomap - create a virtual mapping cookie for a PCI BAR |
99 | * @dev: PCI device that owns the BAR |
100 | * @bar: BAR number |
101 | * @maxlen: length of the memory to map |
102 | * |
103 | * Using this function you will get a __iomem address to your device BAR. |
104 | * You can access it using ioread*() and iowrite*(). These functions hide |
105 | * the details if this is a MMIO or PIO address space and will just do what |
106 | * you expect from them in the correct way. |
107 | * |
108 | * @maxlen specifies the maximum length to map. If you want to get access to |
109 | * the complete BAR without checking for its length first, pass %0 here. |
110 | * */ |
111 | void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) |
112 | { |
113 | return pci_iomap_range(dev, bar, 0, maxlen); |
114 | } |
115 | EXPORT_SYMBOL(pci_iomap); |
116 | |
117 | /** |
118 | * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR |
119 | * @dev: PCI device that owns the BAR |
120 | * @bar: BAR number |
121 | * @maxlen: length of the memory to map |
122 | * |
123 | * Using this function you will get a __iomem address to your device BAR. |
124 | * You can access it using ioread*() and iowrite*(). These functions hide |
125 | * the details if this is a MMIO or PIO address space and will just do what |
126 | * you expect from them in the correct way. When possible write combining |
127 | * is used. |
128 | * |
129 | * @maxlen specifies the maximum length to map. If you want to get access to |
130 | * the complete BAR without checking for its length first, pass %0 here. |
131 | * */ |
132 | void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen) |
133 | { |
134 | return pci_iomap_wc_range(dev, bar, 0, maxlen); |
135 | } |
136 | EXPORT_SYMBOL_GPL(pci_iomap_wc); |
137 | |
138 | /* |
139 | * pci_iounmap() somewhat illogically comes from lib/iomap.c for the |
140 | * CONFIG_GENERIC_IOMAP case, because that's the code that knows about |
141 | * the different IOMAP ranges. |
142 | * |
143 | * But if the architecture does not use the generic iomap code, and if |
144 | * it has _not_ defined it's own private pci_iounmap function, we define |
145 | * it here. |
146 | * |
147 | * NOTE! This default implementation assumes that if the architecture |
148 | * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will |
149 | * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [, |
150 | * and does not need unmapping with 'ioport_unmap()'. |
151 | * |
152 | * If you have different rules for your architecture, you need to |
153 | * implement your own pci_iounmap() that knows the rules for where |
154 | * and how IO vs MEM get mapped. |
155 | * |
156 | * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes |
157 | * from legacy <asm-generic/io.h> header file behavior. In particular, |
158 | * it would seem to make sense to do the iounmap(p) for the non-IO-space |
159 | * case here regardless, but that's not what the old header file code |
160 | * did. Probably incorrectly, but this is meant to be bug-for-bug |
161 | * compatible. |
162 | */ |
163 | #if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP) |
164 | |
165 | void pci_iounmap(struct pci_dev *dev, void __iomem *p) |
166 | { |
167 | #ifdef ARCH_HAS_GENERIC_IOPORT_MAP |
168 | uintptr_t start = (uintptr_t) PCI_IOBASE; |
169 | uintptr_t addr = (uintptr_t) p; |
170 | |
171 | if (addr >= start && addr < start + IO_SPACE_LIMIT) |
172 | return; |
173 | iounmap(p); |
174 | #endif |
175 | } |
176 | EXPORT_SYMBOL(pci_iounmap); |
177 | |
178 | #endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */ |
179 | |
180 | #endif /* CONFIG_PCI */ |
181 | |