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 * */
 28void __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}
 50EXPORT_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 * */
 68void __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}
 95EXPORT_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 * */
111void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
112{
113	return pci_iomap_range(dev, bar, 0, maxlen);
114}
115EXPORT_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 * */
132void __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}
136EXPORT_SYMBOL_GPL(pci_iomap_wc);
137#endif /* CONFIG_PCI */