xref: /openbmc/linux/lib/iomap.c (revision 6ab3d562)
1 /*
2  * Implement the default iomap interfaces
3  *
4  * (C) Copyright 2004 Linus Torvalds
5  */
6 #include <linux/pci.h>
7 #include <linux/module.h>
8 #include <asm/io.h>
9 
10 /*
11  * Read/write from/to an (offsettable) iomem cookie. It might be a PIO
12  * access or a MMIO access, these functions don't care. The info is
13  * encoded in the hardware mapping set up by the mapping functions
14  * (or the cookie itself, depending on implementation and hw).
15  *
16  * The generic routines don't assume any hardware mappings, and just
17  * encode the PIO/MMIO as part of the cookie. They coldly assume that
18  * the MMIO IO mappings are not in the low address range.
19  *
20  * Architectures for which this is not true can't use this generic
21  * implementation and should do their own copy.
22  */
23 
24 #ifndef HAVE_ARCH_PIO_SIZE
25 /*
26  * We encode the physical PIO addresses (0-0xffff) into the
27  * pointer by offsetting them with a constant (0x10000) and
28  * assuming that all the low addresses are always PIO. That means
29  * we can do some sanity checks on the low bits, and don't
30  * need to just take things for granted.
31  */
32 #define PIO_OFFSET	0x10000UL
33 #define PIO_MASK	0x0ffffUL
34 #define PIO_RESERVED	0x40000UL
35 #endif
36 
37 /*
38  * Ugly macros are a way of life.
39  */
40 #define VERIFY_PIO(port) BUG_ON((port & ~PIO_MASK) != PIO_OFFSET)
41 
42 #define IO_COND(addr, is_pio, is_mmio) do {			\
43 	unsigned long port = (unsigned long __force)addr;	\
44 	if (port < PIO_RESERVED) {				\
45 		VERIFY_PIO(port);				\
46 		port &= PIO_MASK;				\
47 		is_pio;						\
48 	} else {						\
49 		is_mmio;					\
50 	}							\
51 } while (0)
52 
53 unsigned int fastcall ioread8(void __iomem *addr)
54 {
55 	IO_COND(addr, return inb(port), return readb(addr));
56 }
57 unsigned int fastcall ioread16(void __iomem *addr)
58 {
59 	IO_COND(addr, return inw(port), return readw(addr));
60 }
61 unsigned int fastcall ioread16be(void __iomem *addr)
62 {
63 	IO_COND(addr, return inw(port), return be16_to_cpu(__raw_readw(addr)));
64 }
65 unsigned int fastcall ioread32(void __iomem *addr)
66 {
67 	IO_COND(addr, return inl(port), return readl(addr));
68 }
69 unsigned int fastcall ioread32be(void __iomem *addr)
70 {
71 	IO_COND(addr, return inl(port), return be32_to_cpu(__raw_readl(addr)));
72 }
73 EXPORT_SYMBOL(ioread8);
74 EXPORT_SYMBOL(ioread16);
75 EXPORT_SYMBOL(ioread16be);
76 EXPORT_SYMBOL(ioread32);
77 EXPORT_SYMBOL(ioread32be);
78 
79 void fastcall iowrite8(u8 val, void __iomem *addr)
80 {
81 	IO_COND(addr, outb(val,port), writeb(val, addr));
82 }
83 void fastcall iowrite16(u16 val, void __iomem *addr)
84 {
85 	IO_COND(addr, outw(val,port), writew(val, addr));
86 }
87 void fastcall iowrite16be(u16 val, void __iomem *addr)
88 {
89 	IO_COND(addr, outw(val,port), __raw_writew(cpu_to_be16(val), addr));
90 }
91 void fastcall iowrite32(u32 val, void __iomem *addr)
92 {
93 	IO_COND(addr, outl(val,port), writel(val, addr));
94 }
95 void fastcall iowrite32be(u32 val, void __iomem *addr)
96 {
97 	IO_COND(addr, outl(val,port), __raw_writel(cpu_to_be32(val), addr));
98 }
99 EXPORT_SYMBOL(iowrite8);
100 EXPORT_SYMBOL(iowrite16);
101 EXPORT_SYMBOL(iowrite16be);
102 EXPORT_SYMBOL(iowrite32);
103 EXPORT_SYMBOL(iowrite32be);
104 
105 /*
106  * These are the "repeat MMIO read/write" functions.
107  * Note the "__raw" accesses, since we don't want to
108  * convert to CPU byte order. We write in "IO byte
109  * order" (we also don't have IO barriers).
110  */
111 static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
112 {
113 	while (--count >= 0) {
114 		u8 data = __raw_readb(addr);
115 		*dst = data;
116 		dst++;
117 	}
118 }
119 static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
120 {
121 	while (--count >= 0) {
122 		u16 data = __raw_readw(addr);
123 		*dst = data;
124 		dst++;
125 	}
126 }
127 static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
128 {
129 	while (--count >= 0) {
130 		u32 data = __raw_readl(addr);
131 		*dst = data;
132 		dst++;
133 	}
134 }
135 
136 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
137 {
138 	while (--count >= 0) {
139 		__raw_writeb(*src, addr);
140 		src++;
141 	}
142 }
143 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
144 {
145 	while (--count >= 0) {
146 		__raw_writew(*src, addr);
147 		src++;
148 	}
149 }
150 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
151 {
152 	while (--count >= 0) {
153 		__raw_writel(*src, addr);
154 		src++;
155 	}
156 }
157 
158 void fastcall ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
159 {
160 	IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
161 }
162 void fastcall ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
163 {
164 	IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
165 }
166 void fastcall ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
167 {
168 	IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
169 }
170 EXPORT_SYMBOL(ioread8_rep);
171 EXPORT_SYMBOL(ioread16_rep);
172 EXPORT_SYMBOL(ioread32_rep);
173 
174 void fastcall iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
175 {
176 	IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
177 }
178 void fastcall iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
179 {
180 	IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
181 }
182 void fastcall iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
183 {
184 	IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
185 }
186 EXPORT_SYMBOL(iowrite8_rep);
187 EXPORT_SYMBOL(iowrite16_rep);
188 EXPORT_SYMBOL(iowrite32_rep);
189 
190 /* Create a virtual mapping cookie for an IO port range */
191 void __iomem *ioport_map(unsigned long port, unsigned int nr)
192 {
193 	if (port > PIO_MASK)
194 		return NULL;
195 	return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
196 }
197 
198 void ioport_unmap(void __iomem *addr)
199 {
200 	/* Nothing to do */
201 }
202 EXPORT_SYMBOL(ioport_map);
203 EXPORT_SYMBOL(ioport_unmap);
204 
205 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
206 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
207 {
208 	unsigned long start = pci_resource_start(dev, bar);
209 	unsigned long len = pci_resource_len(dev, bar);
210 	unsigned long flags = pci_resource_flags(dev, bar);
211 
212 	if (!len || !start)
213 		return NULL;
214 	if (maxlen && len > maxlen)
215 		len = maxlen;
216 	if (flags & IORESOURCE_IO)
217 		return ioport_map(start, len);
218 	if (flags & IORESOURCE_MEM) {
219 		if (flags & IORESOURCE_CACHEABLE)
220 			return ioremap(start, len);
221 		return ioremap_nocache(start, len);
222 	}
223 	/* What? */
224 	return NULL;
225 }
226 
227 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
228 {
229 	IO_COND(addr, /* nothing */, iounmap(addr));
230 }
231 EXPORT_SYMBOL(pci_iomap);
232 EXPORT_SYMBOL(pci_iounmap);
233