xref: /linux/lib/iomap.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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);
283