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 ioread16be(void __iomem *addr)
  62 {
  63         IO_COND(addr, return inw(port), return be16_to_cpu(__raw_readw(addr)));
  64 }
  65 unsigned int fastcall ioread32(void __iomem *addr)
  66 {
  67         IO_COND(addr, return inl(port), return readl(addr));
  68 }
  69 unsigned int fastcall ioread32be(void __iomem *addr)
  70 {
  71         IO_COND(addr, return inl(port), return be32_to_cpu(__raw_readl(addr)));
  72 }
  73 EXPORT_SYMBOL(ioread8);
  74 EXPORT_SYMBOL(ioread16);
  75 EXPORT_SYMBOL(ioread16be);
  76 EXPORT_SYMBOL(ioread32);
  77 EXPORT_SYMBOL(ioread32be);
  78
  79 void fastcall iowrite8(u8 val, void __iomem *addr)
  80 {
  81         IO_COND(addr, outb(val,port), writeb(val, addr));
  82 }
  83 void fastcall iowrite16(u16 val, void __iomem *addr)
  84 {
  85         IO_COND(addr, outw(val,port), writew(val, addr));
  86 }
  87 void fastcall iowrite16be(u16 val, void __iomem *addr)
  88 {
  89         IO_COND(addr, outw(val,port), __raw_writew(cpu_to_be16(val), addr));
  90 }
  91 void fastcall iowrite32(u32 val, void __iomem *addr)
  92 {
  93         IO_COND(addr, outl(val,port), writel(val, addr));
  94 }
  95 void fastcall iowrite32be(u32 val, void __iomem *addr)
  96 {
  97         IO_COND(addr, outl(val,port), __raw_writel(cpu_to_be32(val), addr));
  98 }
  99 EXPORT_SYMBOL(iowrite8);
 100 EXPORT_SYMBOL(iowrite16);
 101 EXPORT_SYMBOL(iowrite16be);
 102 EXPORT_SYMBOL(iowrite32);
 103 EXPORT_SYMBOL(iowrite32be);
 104
 105 /*
 106  * These are the "repeat MMIO read/write" functions.
 107  * Note the "__raw" accesses, since we don't want to
 108  * convert to CPU byte order. We write in "IO byte
 109  * order" (we also don't have IO barriers).
 110  */
 111 static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
 112 {
 113         while (--count >= 0) {
 114                 u8 data = __raw_readb(addr);
 115                 *dst = data;
 116                 dst++;
 117         }
 118 }
 119 static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
 120 {
 121         while (--count >= 0) {
 122                 u16 data = __raw_readw(addr);
 123                 *dst = data;
 124                 dst++;
 125         }
 126 }
 127 static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
 128 {
 129         while (--count >= 0) {
 130                 u32 data = __raw_readl(addr);
 131                 *dst = data;
 132                 dst++;
 133         }
 134 }
 135
 136 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
 137 {
 138         while (--count >= 0) {
 139                 __raw_writeb(*src, addr);
 140                 src++;
 141         }
 142 }
 143 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
 144 {
 145         while (--count >= 0) {
 146                 __raw_writew(*src, addr);
 147                 src++;
 148         }
 149 }
 150 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
 151 {
 152         while (--count >= 0) {
 153                 __raw_writel(*src, addr);
 154                 src++;
 155         }
 156 }
 157
 158 void fastcall ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
 159 {
 160         IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
 161 }
 162 void fastcall ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
 163 {
 164         IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
 165 }
 166 void fastcall ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
 167 {
 168         IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
 169 }
 170 EXPORT_SYMBOL(ioread8_rep);
 171 EXPORT_SYMBOL(ioread16_rep);
 172 EXPORT_SYMBOL(ioread32_rep);
 173
 174 void fastcall iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
 175 {
 176         IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
 177 }
 178 void fastcall iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
 179 {
 180         IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
 181 }
 182 void fastcall iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
 183 {
 184         IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
 185 }
 186 EXPORT_SYMBOL(iowrite8_rep);
 187 EXPORT_SYMBOL(iowrite16_rep);
 188 EXPORT_SYMBOL(iowrite32_rep);
 189
 190 /* Create a virtual mapping cookie for an IO port range */
 191 void __iomem *ioport_map(unsigned long port, unsigned int nr)
 192 {
 193         if (port > PIO_MASK)
 194                 return NULL;
 195         return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
 196 }
 197
 198 void ioport_unmap(void __iomem *addr)
 199 {
 200         /* Nothing to do */
 201 }
 202 EXPORT_SYMBOL(ioport_map);
 203 EXPORT_SYMBOL(ioport_unmap);
 204
 205 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 206 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 207 {
 208         unsigned long start = pci_resource_start(dev, bar);
 209         unsigned long len = pci_resource_len(dev, bar);
 210         unsigned long flags = pci_resource_flags(dev, bar);
 211
 212         if (!len || !start)
 213                 return NULL;
 214         if (maxlen && len > maxlen)
 215                 len = maxlen;
 216         if (flags & IORESOURCE_IO)
 217                 return ioport_map(start, len);
 218         if (flags & IORESOURCE_MEM) {
 219                 if (flags & IORESOURCE_CACHEABLE)
 220                         return ioremap(start, len);
 221                 return ioremap_nocache(start, len);
 222         }
 223         /* What? */
 224         return NULL;
 225 }
 226
 227 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
 228 {
 229         IO_COND(addr, /* nothing */, iounmap(addr));
 230 }
 231 EXPORT_SYMBOL(pci_iomap);
 232 EXPORT_SYMBOL(pci_iounmap);