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 * */
27void __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}
49EXPORT_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 * */
67void __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}
94EXPORT_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 * */
110void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
111{
112	return pci_iomap_range(dev, bar, 0, maxlen);
113}
114EXPORT_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 * */
131void __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}
135EXPORT_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
164void 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}
175EXPORT_SYMBOL(pci_iounmap);
176
177#endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */
178