lib/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/module.h>
   8 #include <asm/io.h>
   9
  10 /*
  11  * Read/write from/to an (offsettable) iomem cookie. It might be a PIO
  12  * access or a MMIO access, these functions don't care. The info is
  13  * encoded in the hardware mapping set up by the mapping functions
  14  * (or the cookie itself, depending on implementation and hw).
  15  *
  16  * The generic routines don't assume any hardware mappings, and just
  17  * encode the PIO/MMIO as part of the cookie. They coldly assume that
  18  * the MMIO IO mappings are not in the low address range.
  19  *
  20  * Architectures for which this is not true can't use this generic
  21  * implementation and should do their own copy.
  22  *
  23  * We encode the physical PIO addresses (0-0xffff) into the
  24  * pointer by offsetting them with a constant (0x10000) and
  25  * assuming that all the low addresses are always PIO. That means
  26  * we can do some sanity checks on the low bits, and don't
  27  * need to just take things for granted.
  28  */
  29 #define PIO_OFFSET      0x10000UL
  30 #define PIO_MASK        0x0ffffUL
  31 #define PIO_RESERVED    0x40000UL
  32
  33 /*
  34  * Ugly macros are a way of life.
  35  */
  36 #define VERIFY_PIO(port) BUG_ON((port & ~PIO_MASK) != PIO_OFFSET)
  37
  38 #define IO_COND(addr, is_pio, is_mmio) do {                     \
  39         unsigned long port = (unsigned long __force)addr;       \
  40         if (port < PIO_RESERVED) {                              \
  41                 VERIFY_PIO(port);                               \
  42                 port &= PIO_MASK;                               \
  43                 is_pio;                                         \
  44         } else {                                                \
  45                 is_mmio;                                        \
  46         }                                                       \
  47 } while (0)
  48
  49 unsigned int fastcall ioread8(void __iomem *addr)
  50 {
  51         IO_COND(addr, return inb(port), return readb(addr));
  52 }
  53 unsigned int fastcall ioread16(void __iomem *addr)
  54 {
  55         IO_COND(addr, return inw(port), return readw(addr));
  56 }
  57 unsigned int fastcall ioread32(void __iomem *addr)
  58 {
  59         IO_COND(addr, return inl(port), return readl(addr));
  60 }
  61 EXPORT_SYMBOL(ioread8);
  62 EXPORT_SYMBOL(ioread16);
  63 EXPORT_SYMBOL(ioread32);
  64
  65 void fastcall iowrite8(u8 val, void __iomem *addr)
  66 {
  67         IO_COND(addr, outb(val,port), writeb(val, addr));
  68 }
  69 void fastcall iowrite16(u16 val, void __iomem *addr)
  70 {
  71         IO_COND(addr, outw(val,port), writew(val, addr));
  72 }
  73 void fastcall iowrite32(u32 val, void __iomem *addr)
  74 {
  75         IO_COND(addr, outl(val,port), writel(val, addr));
  76 }
  77 EXPORT_SYMBOL(iowrite8);
  78 EXPORT_SYMBOL(iowrite16);
  79 EXPORT_SYMBOL(iowrite32);
  80
  81 /*
  82  * These are the "repeat MMIO read/write" functions.
  83  * Note the "__raw" accesses, since we don't want to
  84  * convert to CPU byte order. We write in "IO byte
  85  * order" (we also don't have IO barriers).
  86  */
  87 static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
  88 {
  89         while (--count >= 0) {
  90                 u8 data = __raw_readb(addr);
  91                 *dst = data;
  92                 dst++;
  93         }
  94 }
  95 static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
  96 {
  97         while (--count >= 0) {
  98                 u16 data = __raw_readw(addr);
  99                 *dst = data;
 100                 dst++;
 101         }
 102 }
 103 static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
 104 {
 105         while (--count >= 0) {
 106                 u32 data = __raw_readl(addr);
 107                 *dst = data;
 108                 dst++;
 109         }
 110 }
 111
 112 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
 113 {
 114         while (--count >= 0) {
 115                 __raw_writeb(*src, addr);
 116                 src++;
 117         }
 118 }
 119 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
 120 {
 121         while (--count >= 0) {
 122                 __raw_writew(*src, addr);
 123                 src++;
 124         }
 125 }
 126 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
 127 {
 128         while (--count >= 0) {
 129                 __raw_writel(*src, addr);
 130                 src++;
 131         }
 132 }
 133
 134 void fastcall ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
 135 {
 136         IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
 137 }
 138 void fastcall ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
 139 {
 140         IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
 141 }
 142 void fastcall ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
 143 {
 144         IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
 145 }
 146 EXPORT_SYMBOL(ioread8_rep);
 147 EXPORT_SYMBOL(ioread16_rep);
 148 EXPORT_SYMBOL(ioread32_rep);
 149
 150 void fastcall iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
 151 {
 152         IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
 153 }
 154 void fastcall iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
 155 {
 156         IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
 157 }
 158 void fastcall iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
 159 {
 160         IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
 161 }
 162 EXPORT_SYMBOL(iowrite8_rep);
 163 EXPORT_SYMBOL(iowrite16_rep);
 164 EXPORT_SYMBOL(iowrite32_rep);
 165
 166 /* Create a virtual mapping cookie for an IO port range */
 167 void __iomem *ioport_map(unsigned long port, unsigned int nr)
 168 {
 169         if (port > PIO_MASK)
 170                 return NULL;
 171         return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
 172 }
 173
 174 void ioport_unmap(void __iomem *addr)
 175 {
 176         /* Nothing to do */
 177 }
 178 EXPORT_SYMBOL(ioport_map);
 179 EXPORT_SYMBOL(ioport_unmap);
 180
 181 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 182 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 183 {
 184         unsigned long start = pci_resource_start(dev, bar);
 185         unsigned long len = pci_resource_len(dev, bar);
 186         unsigned long flags = pci_resource_flags(dev, bar);
 187
 188         if (!len || !start)
 189                 return NULL;
 190         if (maxlen && len > maxlen)
 191                 len = maxlen;
 192         if (flags & IORESOURCE_IO)
 193                 return ioport_map(start, len);
 194         if (flags & IORESOURCE_MEM) {
 195                 if (flags & IORESOURCE_CACHEABLE)
 196                         return ioremap(start, len);
 197                 return ioremap_nocache(start, len);
 198         }
 199         /* What? */
 200         return NULL;
 201 }
 202
 203 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
 204 {
 205         IO_COND(addr, /* nothing */, iounmap(addr));
 206 }
 207 EXPORT_SYMBOL(pci_iomap);
 208 EXPORT_SYMBOL(pci_iounmap);