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