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
  24 #ifndef HAVE_ARCH_PIO_SIZE
  25 /*
  26  * We encode the physical PIO addresses (0-0xffff) into the
  27  * pointer by offsetting them with a constant (0x10000) and
  28  * assuming that all the low addresses are always PIO. That means
  29  * we can do some sanity checks on the low bits, and don't
  30  * need to just take things for granted.
  31  */
  32 #define PIO_OFFSET      0x10000UL
  33 #define PIO_MASK        0x0ffffUL
  34 #define PIO_RESERVED    0x40000UL
  35 #endif
  36
  37 /*
  38  * Ugly macros are a way of life.
  39  */
  40 #define VERIFY_PIO(port) BUG_ON((port & ~PIO_MASK) != PIO_OFFSET)
  41
  42 #define IO_COND(addr, is_pio, is_mmio) do {                     \
  43         unsigned long port = (unsigned long __force)addr;       \
  44         if (port < PIO_RESERVED) {                              \
  45                 VERIFY_PIO(port);                               \
  46                 port &= PIO_MASK;                               \
  47                 is_pio;                                         \
  48         } else {                                                \
  49                 is_mmio;                                        \
  50         }                                                       \
  51 } while (0)
  52
  53 unsigned int fastcall ioread8(void __iomem *addr)
  54 {
  55         IO_COND(addr, return inb(port), return readb(addr));
  56 }
  57 unsigned int fastcall ioread16(void __iomem *addr)
  58 {
  59         IO_COND(addr, return inw(port), return readw(addr));
  60 }
  61 unsigned int fastcall ioread32(void __iomem *addr)
  62 {
  63         IO_COND(addr, return inl(port), return readl(addr));
  64 }
  65 EXPORT_SYMBOL(ioread8);
  66 EXPORT_SYMBOL(ioread16);
  67 EXPORT_SYMBOL(ioread32);
  68
  69 void fastcall iowrite8(u8 val, void __iomem *addr)
  70 {
  71         IO_COND(addr, outb(val,port), writeb(val, addr));
  72 }
  73 void fastcall iowrite16(u16 val, void __iomem *addr)
  74 {
  75         IO_COND(addr, outw(val,port), writew(val, addr));
  76 }
  77 void fastcall iowrite32(u32 val, void __iomem *addr)
  78 {
  79         IO_COND(addr, outl(val,port), writel(val, addr));
  80 }
  81 EXPORT_SYMBOL(iowrite8);
  82 EXPORT_SYMBOL(iowrite16);
  83 EXPORT_SYMBOL(iowrite32);
  84
  85 /*
  86  * These are the "repeat MMIO read/write" functions.
  87  * Note the "__raw" accesses, since we don't want to
  88  * convert to CPU byte order. We write in "IO byte
  89  * order" (we also don't have IO barriers).
  90  */
  91 static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
  92 {
  93         while (--count >= 0) {
  94                 u8 data = __raw_readb(addr);
  95                 *dst = data;
  96                 dst++;
  97         }
  98 }
  99 static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
 100 {
 101         while (--count >= 0) {
 102                 u16 data = __raw_readw(addr);
 103                 *dst = data;
 104                 dst++;
 105         }
 106 }
 107 static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
 108 {
 109         while (--count >= 0) {
 110                 u32 data = __raw_readl(addr);
 111                 *dst = data;
 112                 dst++;
 113         }
 114 }
 115
 116 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
 117 {
 118         while (--count >= 0) {
 119                 __raw_writeb(*src, addr);
 120                 src++;
 121         }
 122 }
 123 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
 124 {
 125         while (--count >= 0) {
 126                 __raw_writew(*src, addr);
 127                 src++;
 128         }
 129 }
 130 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
 131 {
 132         while (--count >= 0) {
 133                 __raw_writel(*src, addr);
 134                 src++;
 135         }
 136 }
 137
 138 void fastcall ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
 139 {
 140         IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
 141 }
 142 void fastcall ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
 143 {
 144         IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
 145 }
 146 void fastcall ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
 147 {
 148         IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
 149 }
 150 EXPORT_SYMBOL(ioread8_rep);
 151 EXPORT_SYMBOL(ioread16_rep);
 152 EXPORT_SYMBOL(ioread32_rep);
 153
 154 void fastcall iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
 155 {
 156         IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
 157 }
 158 void fastcall iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
 159 {
 160         IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
 161 }
 162 void fastcall iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
 163 {
 164         IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
 165 }
 166 EXPORT_SYMBOL(iowrite8_rep);
 167 EXPORT_SYMBOL(iowrite16_rep);
 168 EXPORT_SYMBOL(iowrite32_rep);
 169
 170 /* Create a virtual mapping cookie for an IO port range */
 171 void __iomem *ioport_map(unsigned long port, unsigned int nr)
 172 {
 173         if (port > PIO_MASK)
 174                 return NULL;
 175         return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
 176 }
 177
 178 void ioport_unmap(void __iomem *addr)
 179 {
 180         /* Nothing to do */
 181 }
 182 EXPORT_SYMBOL(ioport_map);
 183 EXPORT_SYMBOL(ioport_unmap);
 184
 185 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 186 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 187 {
 188         unsigned long start = pci_resource_start(dev, bar);
 189         unsigned long len = pci_resource_len(dev, bar);
 190         unsigned long flags = pci_resource_flags(dev, bar);
 191
 192         if (!len || !start)
 193                 return NULL;
 194         if (maxlen && len > maxlen)
 195                 len = maxlen;
 196         if (flags & IORESOURCE_IO)
 197                 return ioport_map(start, len);
 198         if (flags & IORESOURCE_MEM) {
 199                 if (flags & IORESOURCE_CACHEABLE)
 200                         return ioremap(start, len);
 201                 return ioremap_nocache(start, len);
 202         }
 203         /* What? */
 204         return NULL;
 205 }
 206
 207 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
 208 {
 209         IO_COND(addr, /* nothing */, iounmap(addr));
 210 }
 211 EXPORT_SYMBOL(pci_iomap);
 212 EXPORT_SYMBOL(pci_iounmap);