xref: /openbmc/linux/lib/pci_iomap.c (revision 3805e6a1)
1 /*
2  * Implement the default iomap interfaces
3  *
4  * (C) Copyright 2004 Linus Torvalds
5  */
6 #include <linux/pci.h>
7 #include <linux/io.h>
8 
9 #include <linux/export.h>
10 
11 #ifdef CONFIG_PCI
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(start, 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(start, 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 #endif /* CONFIG_PCI */
137