lib/pci_iomap.c

   1 /*
   2  * Implement the default iomap interfaces
   3  *
   4  * (C) Copyright 2004 Linus Torvalds
   5  */
   6 #include <linux/pci.h>
   7 #include <linux/io.h>
   8
   9 #include <linux/export.h>
  10
  11 #ifdef CONFIG_PCI
  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 void __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 }
  49 EXPORT_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  * */
  67 void __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 }
  94 EXPORT_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  * */
 110 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 111 {
 112         return pci_iomap_range(dev, bar, 0, maxlen);
 113 }
 114 EXPORT_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  * */
 131 void __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 }
 135 EXPORT_SYMBOL_GPL(pci_iomap_wc);
 136 #endif /* CONFIG_PCI */