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                 if (flags & IORESOURCE_CACHEABLE)
  46                         return ioremap(start, len);
  47                 return ioremap_nocache(start, len);
  48         }
  49         /* What? */
  50         return NULL;
  51 }
  52 EXPORT_SYMBOL(pci_iomap_range);
  53
  54 /**
  55  * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
  56  * @dev: PCI device that owns the BAR
  57  * @bar: BAR number
  58  * @offset: map memory at the given offset in BAR
  59  * @maxlen: max length of the memory to map
  60  *
  61  * Using this function you will get a __iomem address to your device BAR.
  62  * You can access it using ioread*() and iowrite*(). These functions hide
  63  * the details if this is a MMIO or PIO address space and will just do what
  64  * you expect from them in the correct way. When possible write combining
  65  * is used.
  66  *
  67  * @maxlen specifies the maximum length to map. If you want to get access to
  68  * the complete BAR from offset to the end, pass %0 here.
  69  * */
  70 void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
  71                                  int bar,
  72                                  unsigned long offset,
  73                                  unsigned long maxlen)
  74 {
  75         resource_size_t start = pci_resource_start(dev, bar);
  76         resource_size_t len = pci_resource_len(dev, bar);
  77         unsigned long flags = pci_resource_flags(dev, bar);
  78
  79
  80         if (flags & IORESOURCE_IO)
  81                 return NULL;
  82
  83         if (len <= offset || !start)
  84                 return NULL;
  85
  86         len -= offset;
  87         start += offset;
  88         if (maxlen && len > maxlen)
  89                 len = maxlen;
  90
  91         if (flags & IORESOURCE_MEM)
  92                 return ioremap_wc(start, len);
  93
  94         /* What? */
  95         return NULL;
  96 }
  97 EXPORT_SYMBOL_GPL(pci_iomap_wc_range);
  98
  99 /**
 100  * pci_iomap - create a virtual mapping cookie for a PCI BAR
 101  * @dev: PCI device that owns the BAR
 102  * @bar: BAR number
 103  * @maxlen: length of the memory to map
 104  *
 105  * Using this function you will get a __iomem address to your device BAR.
 106  * You can access it using ioread*() and iowrite*(). These functions hide
 107  * the details if this is a MMIO or PIO address space and will just do what
 108  * you expect from them in the correct way.
 109  *
 110  * @maxlen specifies the maximum length to map. If you want to get access to
 111  * the complete BAR without checking for its length first, pass %0 here.
 112  * */
 113 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 114 {
 115         return pci_iomap_range(dev, bar, 0, maxlen);
 116 }
 117 EXPORT_SYMBOL(pci_iomap);
 118
 119 /**
 120  * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR
 121  * @dev: PCI device that owns the BAR
 122  * @bar: BAR number
 123  * @maxlen: length of the memory to map
 124  *
 125  * Using this function you will get a __iomem address to your device BAR.
 126  * You can access it using ioread*() and iowrite*(). These functions hide
 127  * the details if this is a MMIO or PIO address space and will just do what
 128  * you expect from them in the correct way. When possible write combining
 129  * is used.
 130  *
 131  * @maxlen specifies the maximum length to map. If you want to get access to
 132  * the complete BAR without checking for its length first, pass %0 here.
 133  * */
 134 void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen)
 135 {
 136         return pci_iomap_wc_range(dev, bar, 0, maxlen);
 137 }
 138 EXPORT_SYMBOL_GPL(pci_iomap_wc);
 139 #endif /* CONFIG_PCI */