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