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#include "pci.h" /* for pci_bar_index_is_valid() */
13
14/**
15 * pci_iomap_range - create a virtual mapping cookie for a PCI BAR
16 * @dev: PCI device that owns the BAR
17 * @bar: BAR number
18 * @offset: map memory at the given offset in BAR
19 * @maxlen: max length of the memory to map
20 *
21 * Using this function you will get a __iomem address to your device BAR.
22 * You can access it using ioread*() and iowrite*(). These functions hide
23 * the details if this is a MMIO or PIO address space and will just do what
24 * you expect from them in the correct way.
25 *
26 * @maxlen specifies the maximum length to map. If you want to get access to
27 * the complete BAR from offset to the end, pass %0 here.
28 * */
29void __iomem *pci_iomap_range(struct pci_dev *dev,
30 int bar,
31 unsigned long offset,
32 unsigned long maxlen)
33{
34 resource_size_t start, len;
35 unsigned long flags;
36
37 if (!pci_bar_index_is_valid(bar))
38 return NULL;
39
40 start = pci_resource_start(dev, bar);
41 len = pci_resource_len(dev, bar);
42 flags = pci_resource_flags(dev, bar);
43
44 if (len <= offset || !start)
45 return NULL;
46
47 len -= offset;
48 start += offset;
49 if (maxlen && len > maxlen)
50 len = maxlen;
51 if (flags & IORESOURCE_IO)
52 return __pci_ioport_map(dev, start, len);
53 if (flags & IORESOURCE_MEM)
54 return ioremap(offset: start, size: len);
55 /* What? */
56 return NULL;
57}
58EXPORT_SYMBOL(pci_iomap_range);
59
60/**
61 * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
62 * @dev: PCI device that owns the BAR
63 * @bar: BAR number
64 * @offset: map memory at the given offset in BAR
65 * @maxlen: max length of the memory to map
66 *
67 * Using this function you will get a __iomem address to your device BAR.
68 * You can access it using ioread*() and iowrite*(). These functions hide
69 * the details if this is a MMIO or PIO address space and will just do what
70 * you expect from them in the correct way. When possible write combining
71 * is used.
72 *
73 * @maxlen specifies the maximum length to map. If you want to get access to
74 * the complete BAR from offset to the end, pass %0 here.
75 * */
76void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
77 int bar,
78 unsigned long offset,
79 unsigned long maxlen)
80{
81 resource_size_t start, len;
82 unsigned long flags;
83
84 if (!pci_bar_index_is_valid(bar))
85 return NULL;
86
87 start = pci_resource_start(dev, bar);
88 len = pci_resource_len(dev, bar);
89 flags = pci_resource_flags(dev, bar);
90
91 if (len <= offset || !start)
92 return NULL;
93 if (flags & IORESOURCE_IO)
94 return NULL;
95
96 len -= offset;
97 start += offset;
98 if (maxlen && len > maxlen)
99 len = maxlen;
100
101 if (flags & IORESOURCE_MEM)
102 return ioremap_wc(offset: start, size: len);
103
104 /* What? */
105 return NULL;
106}
107EXPORT_SYMBOL_GPL(pci_iomap_wc_range);
108
109/**
110 * pci_iomap - create a virtual mapping cookie for a PCI BAR
111 * @dev: PCI device that owns the BAR
112 * @bar: BAR number
113 * @maxlen: length of the memory to map
114 *
115 * Using this function you will get a __iomem address to your device BAR.
116 * You can access it using ioread*() and iowrite*(). These functions hide
117 * the details if this is a MMIO or PIO address space and will just do what
118 * you expect from them in the correct way.
119 *
120 * @maxlen specifies the maximum length to map. If you want to get access to
121 * the complete BAR without checking for its length first, pass %0 here.
122 * */
123void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
124{
125 return pci_iomap_range(dev, bar, 0, maxlen);
126}
127EXPORT_SYMBOL(pci_iomap);
128
129/**
130 * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR
131 * @dev: PCI device that owns the BAR
132 * @bar: BAR number
133 * @maxlen: length of the memory to map
134 *
135 * Using this function you will get a __iomem address to your device BAR.
136 * You can access it using ioread*() and iowrite*(). These functions hide
137 * the details if this is a MMIO or PIO address space and will just do what
138 * you expect from them in the correct way. When possible write combining
139 * is used.
140 *
141 * @maxlen specifies the maximum length to map. If you want to get access to
142 * the complete BAR without checking for its length first, pass %0 here.
143 * */
144void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen)
145{
146 return pci_iomap_wc_range(dev, bar, 0, maxlen);
147}
148EXPORT_SYMBOL_GPL(pci_iomap_wc);
149
150/*
151 * pci_iounmap() somewhat illogically comes from lib/iomap.c for the
152 * CONFIG_GENERIC_IOMAP case, because that's the code that knows about
153 * the different IOMAP ranges.
154 *
155 * But if the architecture does not use the generic iomap code, and if
156 * it has _not_ defined its own private pci_iounmap function, we define
157 * it here.
158 *
159 * NOTE! This default implementation assumes that if the architecture
160 * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will
161 * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [,
162 * and does not need unmapping with 'ioport_unmap()'.
163 *
164 * If you have different rules for your architecture, you need to
165 * implement your own pci_iounmap() that knows the rules for where
166 * and how IO vs MEM get mapped.
167 *
168 * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes
169 * from legacy <asm-generic/io.h> header file behavior. In particular,
170 * it would seem to make sense to do the iounmap(p) for the non-IO-space
171 * case here regardless, but that's not what the old header file code
172 * did. Probably incorrectly, but this is meant to be bug-for-bug
173 * compatible.
174 */
175#if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP)
176
177void pci_iounmap(struct pci_dev *dev, void __iomem *p)
178{
179#ifdef ARCH_HAS_GENERIC_IOPORT_MAP
180 uintptr_t start = (uintptr_t) PCI_IOBASE;
181 uintptr_t addr = (uintptr_t) p;
182
183 if (addr >= start && addr < start + IO_SPACE_LIMIT)
184 return;
185#endif
186 iounmap(p);
187}
188EXPORT_SYMBOL(pci_iounmap);
189
190#endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */
191