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(start, 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(start, 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 #endif /* CONFIG_PCI */