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/io.h>
   8
   9 #include <linux/module.h>
  10
  11 /*
  12  * Read/write from/to an (offsettable) iomem cookie. It might be a PIO
  13  * access or a MMIO access, these functions don't care. The info is
  14  * encoded in the hardware mapping set up by the mapping functions
  15  * (or the cookie itself, depending on implementation and hw).
  16  *
  17  * The generic routines don't assume any hardware mappings, and just
  18  * encode the PIO/MMIO as part of the cookie. They coldly assume that
  19  * the MMIO IO mappings are not in the low address range.
  20  *
  21  * Architectures for which this is not true can't use this generic
  22  * implementation and should do their own copy.
  23  */
  24
  25 #ifndef HAVE_ARCH_PIO_SIZE
  26 /*
  27  * We encode the physical PIO addresses (0-0xffff) into the
  28  * pointer by offsetting them with a constant (0x10000) and
  29  * assuming that all the low addresses are always PIO. That means
  30  * we can do some sanity checks on the low bits, and don't
  31  * need to just take things for granted.
  32  */
  33 #define PIO_OFFSET      0x10000UL
  34 #define PIO_MASK        0x0ffffUL
  35 #define PIO_RESERVED    0x40000UL
  36 #endif
  37
  38 static void bad_io_access(unsigned long port, const char *access)
  39 {
  40         static int count = 10;
  41         if (count) {
  42                 count--;
  43                 WARN(1, KERN_ERR "Bad IO access at port %#lx (%s)\n", port, access);
  44         }
  45 }
  46
  47 /*
  48  * Ugly macros are a way of life.
  49  */
  50 #define IO_COND(addr, is_pio, is_mmio) do {                     \
  51         unsigned long port = (unsigned long __force)addr;       \
  52         if (port >= PIO_RESERVED) {                             \
  53                 is_mmio;                                        \
  54         } else if (port > PIO_OFFSET) {                         \
  55                 port &= PIO_MASK;                               \
  56                 is_pio;                                         \
  57         } else                                                  \
  58                 bad_io_access(port, #is_pio );                  \
  59 } while (0)
  60
  61 #ifndef pio_read16be
  62 #define pio_read16be(port) swab16(inw(port))
  63 #define pio_read32be(port) swab32(inl(port))
  64 #endif
  65
  66 #ifndef mmio_read16be
  67 #define mmio_read16be(addr) be16_to_cpu(__raw_readw(addr))
  68 #define mmio_read32be(addr) be32_to_cpu(__raw_readl(addr))
  69 #endif
  70
  71 unsigned int ioread8(void __iomem *addr)
  72 {
  73         IO_COND(addr, return inb(port), return readb(addr));
  74         return 0xff;
  75 }
  76 unsigned int ioread16(void __iomem *addr)
  77 {
  78         IO_COND(addr, return inw(port), return readw(addr));
  79         return 0xffff;
  80 }
  81 unsigned int ioread16be(void __iomem *addr)
  82 {
  83         IO_COND(addr, return pio_read16be(port), return mmio_read16be(addr));
  84         return 0xffff;
  85 }
  86 unsigned int ioread32(void __iomem *addr)
  87 {
  88         IO_COND(addr, return inl(port), return readl(addr));
  89         return 0xffffffff;
  90 }
  91 unsigned int ioread32be(void __iomem *addr)
  92 {
  93         IO_COND(addr, return pio_read32be(port), return mmio_read32be(addr));
  94         return 0xffffffff;
  95 }
  96 EXPORT_SYMBOL(ioread8);
  97 EXPORT_SYMBOL(ioread16);
  98 EXPORT_SYMBOL(ioread16be);
  99 EXPORT_SYMBOL(ioread32);
 100 EXPORT_SYMBOL(ioread32be);
 101
 102 #ifndef pio_write16be
 103 #define pio_write16be(val,port) outw(swab16(val),port)
 104 #define pio_write32be(val,port) outl(swab32(val),port)
 105 #endif
 106
 107 #ifndef mmio_write16be
 108 #define mmio_write16be(val,port) __raw_writew(be16_to_cpu(val),port)
 109 #define mmio_write32be(val,port) __raw_writel(be32_to_cpu(val),port)
 110 #endif
 111
 112 void iowrite8(u8 val, void __iomem *addr)
 113 {
 114         IO_COND(addr, outb(val,port), writeb(val, addr));
 115 }
 116 void iowrite16(u16 val, void __iomem *addr)
 117 {
 118         IO_COND(addr, outw(val,port), writew(val, addr));
 119 }
 120 void iowrite16be(u16 val, void __iomem *addr)
 121 {
 122         IO_COND(addr, pio_write16be(val,port), mmio_write16be(val, addr));
 123 }
 124 void iowrite32(u32 val, void __iomem *addr)
 125 {
 126         IO_COND(addr, outl(val,port), writel(val, addr));
 127 }
 128 void iowrite32be(u32 val, void __iomem *addr)
 129 {
 130         IO_COND(addr, pio_write32be(val,port), mmio_write32be(val, addr));
 131 }
 132 EXPORT_SYMBOL(iowrite8);
 133 EXPORT_SYMBOL(iowrite16);
 134 EXPORT_SYMBOL(iowrite16be);
 135 EXPORT_SYMBOL(iowrite32);
 136 EXPORT_SYMBOL(iowrite32be);
 137
 138 /*
 139  * These are the "repeat MMIO read/write" functions.
 140  * Note the "__raw" accesses, since we don't want to
 141  * convert to CPU byte order. We write in "IO byte
 142  * order" (we also don't have IO barriers).
 143  */
 144 #ifndef mmio_insb
 145 static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
 146 {
 147         while (--count >= 0) {
 148                 u8 data = __raw_readb(addr);
 149                 *dst = data;
 150                 dst++;
 151         }
 152 }
 153 static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
 154 {
 155         while (--count >= 0) {
 156                 u16 data = __raw_readw(addr);
 157                 *dst = data;
 158                 dst++;
 159         }
 160 }
 161 static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
 162 {
 163         while (--count >= 0) {
 164                 u32 data = __raw_readl(addr);
 165                 *dst = data;
 166                 dst++;
 167         }
 168 }
 169 #endif
 170
 171 #ifndef mmio_outsb
 172 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
 173 {
 174         while (--count >= 0) {
 175                 __raw_writeb(*src, addr);
 176                 src++;
 177         }
 178 }
 179 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
 180 {
 181         while (--count >= 0) {
 182                 __raw_writew(*src, addr);
 183                 src++;
 184         }
 185 }
 186 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
 187 {
 188         while (--count >= 0) {
 189                 __raw_writel(*src, addr);
 190                 src++;
 191         }
 192 }
 193 #endif
 194
 195 void ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
 196 {
 197         IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
 198 }
 199 void ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
 200 {
 201         IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
 202 }
 203 void ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
 204 {
 205         IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
 206 }
 207 EXPORT_SYMBOL(ioread8_rep);
 208 EXPORT_SYMBOL(ioread16_rep);
 209 EXPORT_SYMBOL(ioread32_rep);
 210
 211 void iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
 212 {
 213         IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
 214 }
 215 void iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
 216 {
 217         IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
 218 }
 219 void iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
 220 {
 221         IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
 222 }
 223 EXPORT_SYMBOL(iowrite8_rep);
 224 EXPORT_SYMBOL(iowrite16_rep);
 225 EXPORT_SYMBOL(iowrite32_rep);
 226
 227 /* Create a virtual mapping cookie for an IO port range */
 228 void __iomem *ioport_map(unsigned long port, unsigned int nr)
 229 {
 230         if (port > PIO_MASK)
 231                 return NULL;
 232         return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
 233 }
 234
 235 void ioport_unmap(void __iomem *addr)
 236 {
 237         /* Nothing to do */
 238 }
 239 EXPORT_SYMBOL(ioport_map);
 240 EXPORT_SYMBOL(ioport_unmap);
 241
 242 /**
 243  * pci_iomap - create a virtual mapping cookie for a PCI BAR
 244  * @dev: PCI device that owns the BAR
 245  * @bar: BAR number
 246  * @maxlen: length of the memory to map
 247  *
 248  * Using this function you will get a __iomem address to your device BAR.
 249  * You can access it using ioread*() and iowrite*(). These functions hide
 250  * the details if this is a MMIO or PIO address space and will just do what
 251  * you expect from them in the correct way.
 252  *
 253  * @maxlen specifies the maximum length to map. If you want to get access to
 254  * the complete BAR without checking for its length first, pass %0 here.
 255  * */
 256 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 257 {
 258         resource_size_t start = pci_resource_start(dev, bar);
 259         resource_size_t len = pci_resource_len(dev, bar);
 260         unsigned long flags = pci_resource_flags(dev, bar);
 261
 262         if (!len || !start)
 263                 return NULL;
 264         if (maxlen && len > maxlen)
 265                 len = maxlen;
 266         if (flags & IORESOURCE_IO)
 267                 return ioport_map(start, len);
 268         if (flags & IORESOURCE_MEM) {
 269                 if (flags & IORESOURCE_CACHEABLE)
 270                         return ioremap(start, len);
 271                 return ioremap_nocache(start, len);
 272         }
 273         /* What? */
 274         return NULL;
 275 }
 276
 277 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
 278 {
 279         IO_COND(addr, /* nothing */, iounmap(addr));
 280 }
 281 EXPORT_SYMBOL(pci_iomap);
 282 EXPORT_SYMBOL(pci_iounmap);