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 *
 27 * NOTE:
 28 * This function is never managed, even if you initialized with
 29 * pcim_enable_device().
 30 * */
 31void __iomem *pci_iomap_range(struct pci_dev *dev,
 32			      int bar,
 33			      unsigned long offset,
 34			      unsigned long maxlen)
 35{
 36	resource_size_t start = pci_resource_start(dev, bar);
 37	resource_size_t len = pci_resource_len(dev, bar);
 38	unsigned long flags = pci_resource_flags(dev, bar);
 39
 40	if (len <= offset || !start)
 41		return NULL;
 42	len -= offset;
 43	start += offset;
 44	if (maxlen && len > maxlen)
 45		len = maxlen;
 46	if (flags & IORESOURCE_IO)
 47		return __pci_ioport_map(dev, start, len);
 48	if (flags & IORESOURCE_MEM)
 49		return ioremap(start, len);
 50	/* What? */
 51	return NULL;
 52}
 53EXPORT_SYMBOL(pci_iomap_range);
 54
 55/**
 56 * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
 57 * @dev: PCI device that owns the BAR
 58 * @bar: BAR number
 59 * @offset: map memory at the given offset in BAR
 60 * @maxlen: max length of the memory to map
 61 *
 62 * Using this function you will get a __iomem address to your device BAR.
 63 * You can access it using ioread*() and iowrite*(). These functions hide
 64 * the details if this is a MMIO or PIO address space and will just do what
 65 * you expect from them in the correct way. When possible write combining
 66 * is used.
 67 *
 68 * @maxlen specifies the maximum length to map. If you want to get access to
 69 * the complete BAR from offset to the end, pass %0 here.
 70 *
 71 * NOTE:
 72 * This function is never managed, even if you initialized with
 73 * pcim_enable_device().
 74 * */
 75void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
 76				 int bar,
 77				 unsigned long offset,
 78				 unsigned long maxlen)
 79{
 80	resource_size_t start = pci_resource_start(dev, bar);
 81	resource_size_t len = pci_resource_len(dev, bar);
 82	unsigned long flags = pci_resource_flags(dev, bar);
 83
 84
 85	if (flags & IORESOURCE_IO)
 86		return NULL;
 87
 88	if (len <= offset || !start)
 89		return NULL;
 90
 91	len -= offset;
 92	start += offset;
 93	if (maxlen && len > maxlen)
 94		len = maxlen;
 95
 96	if (flags & IORESOURCE_MEM)
 97		return ioremap_wc(start, len);
 98
 99	/* What? */
100	return NULL;
101}
102EXPORT_SYMBOL_GPL(pci_iomap_wc_range);
103
104/**
105 * pci_iomap - create a virtual mapping cookie for a PCI BAR
106 * @dev: PCI device that owns the BAR
107 * @bar: BAR number
108 * @maxlen: length of the memory to map
109 *
110 * Using this function you will get a __iomem address to your device BAR.
111 * You can access it using ioread*() and iowrite*(). These functions hide
112 * the details if this is a MMIO or PIO address space and will just do what
113 * you expect from them in the correct way.
114 *
115 * @maxlen specifies the maximum length to map. If you want to get access to
116 * the complete BAR without checking for its length first, pass %0 here.
117 *
118 * NOTE:
119 * This function is never managed, even if you initialized with
120 * pcim_enable_device(). If you need automatic cleanup, use pcim_iomap().
121 * */
122void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
123{
124	return pci_iomap_range(dev, bar, 0, maxlen);
125}
126EXPORT_SYMBOL(pci_iomap);
127
128/**
129 * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR
130 * @dev: PCI device that owns the BAR
131 * @bar: BAR number
132 * @maxlen: length of the memory to map
133 *
134 * Using this function you will get a __iomem address to your device BAR.
135 * You can access it using ioread*() and iowrite*(). These functions hide
136 * the details if this is a MMIO or PIO address space and will just do what
137 * you expect from them in the correct way. When possible write combining
138 * is used.
139 *
140 * @maxlen specifies the maximum length to map. If you want to get access to
141 * the complete BAR without checking for its length first, pass %0 here.
142 *
143 * NOTE:
144 * This function is never managed, even if you initialized with
145 * pcim_enable_device().
146 * */
147void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen)
148{
149	return pci_iomap_wc_range(dev, bar, 0, maxlen);
150}
151EXPORT_SYMBOL_GPL(pci_iomap_wc);
152
153/*
154 * pci_iounmap() somewhat illogically comes from lib/iomap.c for the
155 * CONFIG_GENERIC_IOMAP case, because that's the code that knows about
156 * the different IOMAP ranges.
157 *
158 * But if the architecture does not use the generic iomap code, and if
159 * it has _not_ defined its own private pci_iounmap function, we define
160 * it here.
161 *
162 * NOTE! This default implementation assumes that if the architecture
163 * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will
164 * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [,
165 * and does not need unmapping with 'ioport_unmap()'.
166 *
167 * If you have different rules for your architecture, you need to
168 * implement your own pci_iounmap() that knows the rules for where
169 * and how IO vs MEM get mapped.
170 *
171 * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes
172 * from legacy <asm-generic/io.h> header file behavior. In particular,
173 * it would seem to make sense to do the iounmap(p) for the non-IO-space
174 * case here regardless, but that's not what the old header file code
175 * did. Probably incorrectly, but this is meant to be bug-for-bug
176 * compatible.
177 */
178#if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP)
179
180void pci_iounmap(struct pci_dev *dev, void __iomem *p)
181{
182#ifdef ARCH_HAS_GENERIC_IOPORT_MAP
183	uintptr_t start = (uintptr_t) PCI_IOBASE;
184	uintptr_t addr = (uintptr_t) p;
185
186	if (addr >= start && addr < start + IO_SPACE_LIMIT)
187		return;
188#endif
189	iounmap(p);
190}
191EXPORT_SYMBOL(pci_iounmap);
192
193#endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */