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 */