linux/lib/iomap.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Implement the default iomap interfaces
   4 *
   5 * (C) Copyright 2004 Linus Torvalds
   6 */
   7#include <linux/pci.h>
   8#include <linux/io.h>
   9
  10#include <linux/export.h>
  11
  12/*
  13 * Read/write from/to an (offsettable) iomem cookie. It might be a PIO
  14 * access or a MMIO access, these functions don't care. The info is
  15 * encoded in the hardware mapping set up by the mapping functions
  16 * (or the cookie itself, depending on implementation and hw).
  17 *
  18 * The generic routines don't assume any hardware mappings, and just
  19 * encode the PIO/MMIO as part of the cookie. They coldly assume that
  20 * the MMIO IO mappings are not in the low address range.
  21 *
  22 * Architectures for which this is not true can't use this generic
  23 * implementation and should do their own copy.
  24 */
  25
  26#ifndef HAVE_ARCH_PIO_SIZE
  27/*
  28 * We encode the physical PIO addresses (0-0xffff) into the
  29 * pointer by offsetting them with a constant (0x10000) and
  30 * assuming that all the low addresses are always PIO. That means
  31 * we can do some sanity checks on the low bits, and don't
  32 * need to just take things for granted.
  33 */
  34#define PIO_OFFSET      0x10000UL
  35#define PIO_MASK        0x0ffffUL
  36#define PIO_RESERVED    0x40000UL
  37#endif
  38
  39static void bad_io_access(unsigned long port, const char *access)
  40{
  41        static int count = 10;
  42        if (count) {
  43                count--;
  44                WARN(1, KERN_ERR "Bad IO access at port %#lx (%s)\n", port, access);
  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
  72unsigned int ioread8(void __iomem *addr)
  73{
  74        IO_COND(addr, return inb(port), return readb(addr));
  75        return 0xff;
  76}
  77unsigned int ioread16(void __iomem *addr)
  78{
  79        IO_COND(addr, return inw(port), return readw(addr));
  80        return 0xffff;
  81}
  82unsigned int ioread16be(void __iomem *addr)
  83{
  84        IO_COND(addr, return pio_read16be(port), return mmio_read16be(addr));
  85        return 0xffff;
  86}
  87unsigned int ioread32(void __iomem *addr)
  88{
  89        IO_COND(addr, return inl(port), return readl(addr));
  90        return 0xffffffff;
  91}
  92unsigned int ioread32be(void __iomem *addr)
  93{
  94        IO_COND(addr, return pio_read32be(port), return mmio_read32be(addr));
  95        return 0xffffffff;
  96}
  97EXPORT_SYMBOL(ioread8);
  98EXPORT_SYMBOL(ioread16);
  99EXPORT_SYMBOL(ioread16be);
 100EXPORT_SYMBOL(ioread32);
 101EXPORT_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
 113void iowrite8(u8 val, void __iomem *addr)
 114{
 115        IO_COND(addr, outb(val,port), writeb(val, addr));
 116}
 117void iowrite16(u16 val, void __iomem *addr)
 118{
 119        IO_COND(addr, outw(val,port), writew(val, addr));
 120}
 121void iowrite16be(u16 val, void __iomem *addr)
 122{
 123        IO_COND(addr, pio_write16be(val,port), mmio_write16be(val, addr));
 124}
 125void iowrite32(u32 val, void __iomem *addr)
 126{
 127        IO_COND(addr, outl(val,port), writel(val, addr));
 128}
 129void iowrite32be(u32 val, void __iomem *addr)
 130{
 131        IO_COND(addr, pio_write32be(val,port), mmio_write32be(val, addr));
 132}
 133EXPORT_SYMBOL(iowrite8);
 134EXPORT_SYMBOL(iowrite16);
 135EXPORT_SYMBOL(iowrite16be);
 136EXPORT_SYMBOL(iowrite32);
 137EXPORT_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
 146static 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}
 154static 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}
 162static 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
 173static 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}
 180static 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}
 187static 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
 196void 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}
 200void 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}
 204void 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}
 208EXPORT_SYMBOL(ioread8_rep);
 209EXPORT_SYMBOL(ioread16_rep);
 210EXPORT_SYMBOL(ioread32_rep);
 211
 212void 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}
 216void 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}
 220void 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}
 224EXPORT_SYMBOL(iowrite8_rep);
 225EXPORT_SYMBOL(iowrite16_rep);
 226EXPORT_SYMBOL(iowrite32_rep);
 227
 228#ifdef CONFIG_HAS_IOPORT_MAP
 229/* Create a virtual mapping cookie for an IO port range */
 230void __iomem *ioport_map(unsigned long port, unsigned int nr)
 231{
 232        if (port > PIO_MASK)
 233                return NULL;
 234        return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
 235}
 236
 237void ioport_unmap(void __iomem *addr)
 238{
 239        /* Nothing to do */
 240}
 241EXPORT_SYMBOL(ioport_map);
 242EXPORT_SYMBOL(ioport_unmap);
 243#endif /* CONFIG_HAS_IOPORT_MAP */
 244
 245#ifdef CONFIG_PCI
 246/* Hide the details if this is a MMIO or PIO address space and just do what
 247 * you expect in the correct way. */
 248void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
 249{
 250        IO_COND(addr, /* nothing */, iounmap(addr));
 251}
 252EXPORT_SYMBOL(pci_iounmap);
 253#endif /* CONFIG_PCI */
 254