lib/iomap.c

   1 /*
   2  * Implement the default iomap interfaces
   3  */
   4 #include <linux/pci.h>
   5 #include <linux/module.h>
   6 #include <asm/io.h>
   7
   8 /*
   9  * Read/write from/to an (offsettable) iomem cookie. It might be a PIO
  10  * access or a MMIO access, these functions don't care. The info is
  11  * encoded in the hardware mapping set up by the mapping functions
  12  * (or the cookie itself, depending on implementation and hw).
  13  *
  14  * The generic routines don't assume any hardware mappings, and just
  15  * encode the PIO/MMIO as part of the cookie. They coldly assume that
  16  * the MMIO IO mappings are not in the low address range.
  17  *
  18  * Architectures for which this is not true can't use this generic
  19  * implementation and should do their own copy.
  20  *
  21  * We encode the physical PIO addresses (0-0xffff) into the
  22  * pointer by offsetting them with a constant (0x10000) and
  23  * assuming that all the low addresses are always PIO. That means
  24  * we can do some sanity checks on the low bits, and don't
  25  * need to just take things for granted.
  26  */
  27 #define PIO_OFFSET      0x10000UL
  28 #define PIO_MASK        0x0ffffUL
  29 #define PIO_RESERVED    0x40000UL
  30
  31 /*
  32  * Ugly macros are a way of life.
  33  */
  34 #define VERIFY_PIO(port) BUG_ON((port & ~PIO_MASK) != PIO_OFFSET)
  35
  36 #define IO_COND(addr, is_pio, is_mmio) do {                     \
  37         unsigned long port = (unsigned long __force)addr;       \
  38         if (port < PIO_RESERVED) {                              \
  39                 VERIFY_PIO(port);                               \
  40                 port &= PIO_MASK;                               \
  41                 is_pio;                                         \
  42         } else {                                                \
  43                 is_mmio;                                        \
  44         }                                                       \
  45 } while (0)
  46
  47 unsigned int fastcall ioread8(void __iomem *addr)
  48 {
  49         IO_COND(addr, return inb(port), return readb(addr));
  50 }
  51 unsigned int fastcall ioread16(void __iomem *addr)
  52 {
  53         IO_COND(addr, return inw(port), return readw(addr));
  54 }
  55 unsigned int fastcall ioread32(void __iomem *addr)
  56 {
  57         IO_COND(addr, return inl(port), return readl(addr));
  58 }
  59 EXPORT_SYMBOL(ioread8);
  60 EXPORT_SYMBOL(ioread16);
  61 EXPORT_SYMBOL(ioread32);
  62
  63 void fastcall iowrite8(u8 val, void __iomem *addr)
  64 {
  65         IO_COND(addr, outb(val,port), writeb(val, addr));
  66 }
  67 void fastcall iowrite16(u16 val, void __iomem *addr)
  68 {
  69         IO_COND(addr, outw(val,port), writew(val, addr));
  70 }
  71 void fastcall iowrite32(u32 val, void __iomem *addr)
  72 {
  73         IO_COND(addr, outl(val,port), writel(val, addr));
  74 }
  75 EXPORT_SYMBOL(iowrite8);
  76 EXPORT_SYMBOL(iowrite16);
  77 EXPORT_SYMBOL(iowrite32);
  78
  79 /*
  80  * These are the "repeat MMIO read/write" functions.
  81  * Note the "__raw" accesses, since we don't want to
  82  * convert to CPU byte order. We write in "IO byte
  83  * order" (we also don't have IO barriers).
  84  */
  85 static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
  86 {
  87         while (--count >= 0) {
  88                 u8 data = __raw_readb(addr);
  89                 *dst = data;
  90                 dst++;
  91         }
  92 }
  93 static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
  94 {
  95         while (--count >= 0) {
  96                 u16 data = __raw_readw(addr);
  97                 *dst = data;
  98                 dst++;
  99         }
 100 }
 101 static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
 102 {
 103         while (--count >= 0) {
 104                 u32 data = __raw_readl(addr);
 105                 *dst = data;
 106                 dst++;
 107         }
 108 }
 109
 110 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
 111 {
 112         while (--count >= 0) {
 113                 __raw_writeb(*src, addr);
 114                 src++;
 115         }
 116 }
 117 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
 118 {
 119         while (--count >= 0) {
 120                 __raw_writew(*src, addr);
 121                 src++;
 122         }
 123 }
 124 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
 125 {
 126         while (--count >= 0) {
 127                 __raw_writel(*src, addr);
 128                 src++;
 129         }
 130 }
 131
 132 void fastcall ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
 133 {
 134         IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
 135 }
 136 void fastcall ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
 137 {
 138         IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
 139 }
 140 void fastcall ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
 141 {
 142         IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
 143 }
 144 EXPORT_SYMBOL(ioread8_rep);
 145 EXPORT_SYMBOL(ioread16_rep);
 146 EXPORT_SYMBOL(ioread32_rep);
 147
 148 void fastcall iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
 149 {
 150         IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
 151 }
 152 void fastcall iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
 153 {
 154         IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
 155 }
 156 void fastcall iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
 157 {
 158         IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
 159 }
 160 EXPORT_SYMBOL(iowrite8_rep);
 161 EXPORT_SYMBOL(iowrite16_rep);
 162 EXPORT_SYMBOL(iowrite32_rep);
 163
 164 /* Create a virtual mapping cookie for an IO port range */
 165 void __iomem *ioport_map(unsigned long port, unsigned int nr)
 166 {
 167         if (port > PIO_MASK)
 168                 return NULL;
 169         return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
 170 }
 171
 172 void ioport_unmap(void __iomem *addr)
 173 {
 174         /* Nothing to do */
 175 }
 176 EXPORT_SYMBOL(ioport_map);
 177 EXPORT_SYMBOL(ioport_unmap);
 178
 179 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 180 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 181 {
 182         unsigned long start = pci_resource_start(dev, bar);
 183         unsigned long len = pci_resource_len(dev, bar);
 184         unsigned long flags = pci_resource_flags(dev, bar);
 185
 186         if (!len || !start)
 187                 return NULL;
 188         if (maxlen && len > maxlen)
 189                 len = maxlen;
 190         if (flags & IORESOURCE_IO)
 191                 return ioport_map(start, len);
 192         if (flags & IORESOURCE_MEM) {
 193                 if (flags & IORESOURCE_CACHEABLE)
 194                         return ioremap(start, len);
 195                 return ioremap_nocache(start, len);
 196         }
 197         /* What? */
 198         return NULL;
 199 }
 200
 201 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
 202 {
 203         IO_COND(addr, /* nothing */, iounmap(addr));
 204 }
 205 EXPORT_SYMBOL(pci_iomap);
 206 EXPORT_SYMBOL(pci_iounmap);