Root/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
38static 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
71unsigned int ioread8(void __iomem *addr)
72{
73    IO_COND(addr, return inb(port), return readb(addr));
74    return 0xff;
75}
76unsigned int ioread16(void __iomem *addr)
77{
78    IO_COND(addr, return inw(port), return readw(addr));
79    return 0xffff;
80}
81unsigned int ioread16be(void __iomem *addr)
82{
83    IO_COND(addr, return pio_read16be(port), return mmio_read16be(addr));
84    return 0xffff;
85}
86unsigned int ioread32(void __iomem *addr)
87{
88    IO_COND(addr, return inl(port), return readl(addr));
89    return 0xffffffff;
90}
91unsigned int ioread32be(void __iomem *addr)
92{
93    IO_COND(addr, return pio_read32be(port), return mmio_read32be(addr));
94    return 0xffffffff;
95}
96EXPORT_SYMBOL(ioread8);
97EXPORT_SYMBOL(ioread16);
98EXPORT_SYMBOL(ioread16be);
99EXPORT_SYMBOL(ioread32);
100EXPORT_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
112void iowrite8(u8 val, void __iomem *addr)
113{
114    IO_COND(addr, outb(val,port), writeb(val, addr));
115}
116void iowrite16(u16 val, void __iomem *addr)
117{
118    IO_COND(addr, outw(val,port), writew(val, addr));
119}
120void iowrite16be(u16 val, void __iomem *addr)
121{
122    IO_COND(addr, pio_write16be(val,port), mmio_write16be(val, addr));
123}
124void iowrite32(u32 val, void __iomem *addr)
125{
126    IO_COND(addr, outl(val,port), writel(val, addr));
127}
128void iowrite32be(u32 val, void __iomem *addr)
129{
130    IO_COND(addr, pio_write32be(val,port), mmio_write32be(val, addr));
131}
132EXPORT_SYMBOL(iowrite8);
133EXPORT_SYMBOL(iowrite16);
134EXPORT_SYMBOL(iowrite16be);
135EXPORT_SYMBOL(iowrite32);
136EXPORT_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
145static 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}
153static 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}
161static 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
172static 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}
179static 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}
186static 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
195void 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}
199void 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}
203void 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}
207EXPORT_SYMBOL(ioread8_rep);
208EXPORT_SYMBOL(ioread16_rep);
209EXPORT_SYMBOL(ioread32_rep);
210
211void 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}
215void 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}
219void 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}
223EXPORT_SYMBOL(iowrite8_rep);
224EXPORT_SYMBOL(iowrite16_rep);
225EXPORT_SYMBOL(iowrite32_rep);
226
227/* Create a virtual mapping cookie for an IO port range */
228void __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
235void ioport_unmap(void __iomem *addr)
236{
237    /* Nothing to do */
238}
239EXPORT_SYMBOL(ioport_map);
240EXPORT_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 * */
256void __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
277void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
278{
279    IO_COND(addr, /* nothing */, iounmap(addr));
280}
281EXPORT_SYMBOL(pci_iomap);
282EXPORT_SYMBOL(pci_iounmap);
283

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