xref: /kernel/linux/linux-5.10/lib/pci_iomap.c (revision 8c2ecf20)
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 * */
28void __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(start, len);
47	/* What? */
48	return NULL;
49}
50EXPORT_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 * */
68void __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(start, len);
91
92	/* What? */
93	return NULL;
94}
95EXPORT_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 * */
111void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
112{
113	return pci_iomap_range(dev, bar, 0, maxlen);
114}
115EXPORT_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 * */
132void __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}
136EXPORT_SYMBOL_GPL(pci_iomap_wc);
137#endif /* CONFIG_PCI */
138