lib/pci_iomap.c

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