xref: /openbmc/linux/lib/iomap.c (revision f07b2b3f)
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 #include <linux/kmsan-checks.h>
10 
11 #include <linux/export.h>
12 
13 /*
14  * Read/write from/to an (offsettable) iomem cookie. It might be a PIO
15  * access or a MMIO access, these functions don't care. The info is
16  * encoded in the hardware mapping set up by the mapping functions
17  * (or the cookie itself, depending on implementation and hw).
18  *
19  * The generic routines don't assume any hardware mappings, and just
20  * encode the PIO/MMIO as part of the cookie. They coldly assume that
21  * the MMIO IO mappings are not in the low address range.
22  *
23  * Architectures for which this is not true can't use this generic
24  * implementation and should do their own copy.
25  */
26 
27 #ifndef HAVE_ARCH_PIO_SIZE
28 /*
29  * We encode the physical PIO addresses (0-0xffff) into the
30  * pointer by offsetting them with a constant (0x10000) and
31  * assuming that all the low addresses are always PIO. That means
32  * we can do some sanity checks on the low bits, and don't
33  * need to just take things for granted.
34  */
35 #define PIO_OFFSET	0x10000UL
36 #define PIO_MASK	0x0ffffUL
37 #define PIO_RESERVED	0x40000UL
38 #endif
39 
40 static void bad_io_access(unsigned long port, const char *access)
41 {
42 	static int count = 10;
43 	if (count) {
44 		count--;
45 		WARN(1, KERN_ERR "Bad IO access at port %#lx (%s)\n", port, access);
46 	}
47 }
48 
49 /*
50  * Ugly macros are a way of life.
51  */
52 #define IO_COND(addr, is_pio, is_mmio) do {			\
53 	unsigned long port = (unsigned long __force)addr;	\
54 	if (port >= PIO_RESERVED) {				\
55 		is_mmio;					\
56 	} else if (port > PIO_OFFSET) {				\
57 		port &= PIO_MASK;				\
58 		is_pio;						\
59 	} else							\
60 		bad_io_access(port, #is_pio );			\
61 } while (0)
62 
63 #ifndef pio_read16be
64 #define pio_read16be(port) swab16(inw(port))
65 #define pio_read32be(port) swab32(inl(port))
66 #endif
67 
68 #ifndef mmio_read16be
69 #define mmio_read16be(addr) swab16(readw(addr))
70 #define mmio_read32be(addr) swab32(readl(addr))
71 #define mmio_read64be(addr) swab64(readq(addr))
72 #endif
73 
74 /*
75  * Here and below, we apply __no_kmsan_checks to functions reading data from
76  * hardware, to ensure that KMSAN marks their return values as initialized.
77  */
78 __no_kmsan_checks
79 unsigned int ioread8(const void __iomem *addr)
80 {
81 	IO_COND(addr, return inb(port), return readb(addr));
82 	return 0xff;
83 }
84 __no_kmsan_checks
85 unsigned int ioread16(const void __iomem *addr)
86 {
87 	IO_COND(addr, return inw(port), return readw(addr));
88 	return 0xffff;
89 }
90 __no_kmsan_checks
91 unsigned int ioread16be(const void __iomem *addr)
92 {
93 	IO_COND(addr, return pio_read16be(port), return mmio_read16be(addr));
94 	return 0xffff;
95 }
96 __no_kmsan_checks
97 unsigned int ioread32(const void __iomem *addr)
98 {
99 	IO_COND(addr, return inl(port), return readl(addr));
100 	return 0xffffffff;
101 }
102 __no_kmsan_checks
103 unsigned int ioread32be(const void __iomem *addr)
104 {
105 	IO_COND(addr, return pio_read32be(port), return mmio_read32be(addr));
106 	return 0xffffffff;
107 }
108 EXPORT_SYMBOL(ioread8);
109 EXPORT_SYMBOL(ioread16);
110 EXPORT_SYMBOL(ioread16be);
111 EXPORT_SYMBOL(ioread32);
112 EXPORT_SYMBOL(ioread32be);
113 
114 #ifdef readq
115 static u64 pio_read64_lo_hi(unsigned long port)
116 {
117 	u64 lo, hi;
118 
119 	lo = inl(port);
120 	hi = inl(port + sizeof(u32));
121 
122 	return lo | (hi << 32);
123 }
124 
125 static u64 pio_read64_hi_lo(unsigned long port)
126 {
127 	u64 lo, hi;
128 
129 	hi = inl(port + sizeof(u32));
130 	lo = inl(port);
131 
132 	return lo | (hi << 32);
133 }
134 
135 static u64 pio_read64be_lo_hi(unsigned long port)
136 {
137 	u64 lo, hi;
138 
139 	lo = pio_read32be(port + sizeof(u32));
140 	hi = pio_read32be(port);
141 
142 	return lo | (hi << 32);
143 }
144 
145 static u64 pio_read64be_hi_lo(unsigned long port)
146 {
147 	u64 lo, hi;
148 
149 	hi = pio_read32be(port);
150 	lo = pio_read32be(port + sizeof(u32));
151 
152 	return lo | (hi << 32);
153 }
154 
155 __no_kmsan_checks
156 u64 ioread64_lo_hi(const void __iomem *addr)
157 {
158 	IO_COND(addr, return pio_read64_lo_hi(port), return readq(addr));
159 	return 0xffffffffffffffffULL;
160 }
161 
162 __no_kmsan_checks
163 u64 ioread64_hi_lo(const void __iomem *addr)
164 {
165 	IO_COND(addr, return pio_read64_hi_lo(port), return readq(addr));
166 	return 0xffffffffffffffffULL;
167 }
168 
169 __no_kmsan_checks
170 u64 ioread64be_lo_hi(const void __iomem *addr)
171 {
172 	IO_COND(addr, return pio_read64be_lo_hi(port),
173 		return mmio_read64be(addr));
174 	return 0xffffffffffffffffULL;
175 }
176 
177 __no_kmsan_checks
178 u64 ioread64be_hi_lo(const void __iomem *addr)
179 {
180 	IO_COND(addr, return pio_read64be_hi_lo(port),
181 		return mmio_read64be(addr));
182 	return 0xffffffffffffffffULL;
183 }
184 
185 EXPORT_SYMBOL(ioread64_lo_hi);
186 EXPORT_SYMBOL(ioread64_hi_lo);
187 EXPORT_SYMBOL(ioread64be_lo_hi);
188 EXPORT_SYMBOL(ioread64be_hi_lo);
189 
190 #endif /* readq */
191 
192 #ifndef pio_write16be
193 #define pio_write16be(val,port) outw(swab16(val),port)
194 #define pio_write32be(val,port) outl(swab32(val),port)
195 #endif
196 
197 #ifndef mmio_write16be
198 #define mmio_write16be(val,port) writew(swab16(val),port)
199 #define mmio_write32be(val,port) writel(swab32(val),port)
200 #define mmio_write64be(val,port) writeq(swab64(val),port)
201 #endif
202 
203 void iowrite8(u8 val, void __iomem *addr)
204 {
205 	/* Make sure uninitialized memory isn't copied to devices. */
206 	kmsan_check_memory(&val, sizeof(val));
207 	IO_COND(addr, outb(val,port), writeb(val, addr));
208 }
209 void iowrite16(u16 val, void __iomem *addr)
210 {
211 	/* Make sure uninitialized memory isn't copied to devices. */
212 	kmsan_check_memory(&val, sizeof(val));
213 	IO_COND(addr, outw(val,port), writew(val, addr));
214 }
215 void iowrite16be(u16 val, void __iomem *addr)
216 {
217 	/* Make sure uninitialized memory isn't copied to devices. */
218 	kmsan_check_memory(&val, sizeof(val));
219 	IO_COND(addr, pio_write16be(val,port), mmio_write16be(val, addr));
220 }
221 void iowrite32(u32 val, void __iomem *addr)
222 {
223 	/* Make sure uninitialized memory isn't copied to devices. */
224 	kmsan_check_memory(&val, sizeof(val));
225 	IO_COND(addr, outl(val,port), writel(val, addr));
226 }
227 void iowrite32be(u32 val, void __iomem *addr)
228 {
229 	/* Make sure uninitialized memory isn't copied to devices. */
230 	kmsan_check_memory(&val, sizeof(val));
231 	IO_COND(addr, pio_write32be(val,port), mmio_write32be(val, addr));
232 }
233 EXPORT_SYMBOL(iowrite8);
234 EXPORT_SYMBOL(iowrite16);
235 EXPORT_SYMBOL(iowrite16be);
236 EXPORT_SYMBOL(iowrite32);
237 EXPORT_SYMBOL(iowrite32be);
238 
239 #ifdef writeq
240 static void pio_write64_lo_hi(u64 val, unsigned long port)
241 {
242 	outl(val, port);
243 	outl(val >> 32, port + sizeof(u32));
244 }
245 
246 static void pio_write64_hi_lo(u64 val, unsigned long port)
247 {
248 	outl(val >> 32, port + sizeof(u32));
249 	outl(val, port);
250 }
251 
252 static void pio_write64be_lo_hi(u64 val, unsigned long port)
253 {
254 	pio_write32be(val, port + sizeof(u32));
255 	pio_write32be(val >> 32, port);
256 }
257 
258 static void pio_write64be_hi_lo(u64 val, unsigned long port)
259 {
260 	pio_write32be(val >> 32, port);
261 	pio_write32be(val, port + sizeof(u32));
262 }
263 
264 void iowrite64_lo_hi(u64 val, void __iomem *addr)
265 {
266 	/* Make sure uninitialized memory isn't copied to devices. */
267 	kmsan_check_memory(&val, sizeof(val));
268 	IO_COND(addr, pio_write64_lo_hi(val, port),
269 		writeq(val, addr));
270 }
271 
272 void iowrite64_hi_lo(u64 val, void __iomem *addr)
273 {
274 	/* Make sure uninitialized memory isn't copied to devices. */
275 	kmsan_check_memory(&val, sizeof(val));
276 	IO_COND(addr, pio_write64_hi_lo(val, port),
277 		writeq(val, addr));
278 }
279 
280 void iowrite64be_lo_hi(u64 val, void __iomem *addr)
281 {
282 	/* Make sure uninitialized memory isn't copied to devices. */
283 	kmsan_check_memory(&val, sizeof(val));
284 	IO_COND(addr, pio_write64be_lo_hi(val, port),
285 		mmio_write64be(val, addr));
286 }
287 
288 void iowrite64be_hi_lo(u64 val, void __iomem *addr)
289 {
290 	/* Make sure uninitialized memory isn't copied to devices. */
291 	kmsan_check_memory(&val, sizeof(val));
292 	IO_COND(addr, pio_write64be_hi_lo(val, port),
293 		mmio_write64be(val, addr));
294 }
295 
296 EXPORT_SYMBOL(iowrite64_lo_hi);
297 EXPORT_SYMBOL(iowrite64_hi_lo);
298 EXPORT_SYMBOL(iowrite64be_lo_hi);
299 EXPORT_SYMBOL(iowrite64be_hi_lo);
300 
301 #endif /* readq */
302 
303 /*
304  * These are the "repeat MMIO read/write" functions.
305  * Note the "__raw" accesses, since we don't want to
306  * convert to CPU byte order. We write in "IO byte
307  * order" (we also don't have IO barriers).
308  */
309 #ifndef mmio_insb
310 static inline void mmio_insb(const void __iomem *addr, u8 *dst, int count)
311 {
312 	while (--count >= 0) {
313 		u8 data = __raw_readb(addr);
314 		*dst = data;
315 		dst++;
316 	}
317 }
318 static inline void mmio_insw(const void __iomem *addr, u16 *dst, int count)
319 {
320 	while (--count >= 0) {
321 		u16 data = __raw_readw(addr);
322 		*dst = data;
323 		dst++;
324 	}
325 }
326 static inline void mmio_insl(const void __iomem *addr, u32 *dst, int count)
327 {
328 	while (--count >= 0) {
329 		u32 data = __raw_readl(addr);
330 		*dst = data;
331 		dst++;
332 	}
333 }
334 #endif
335 
336 #ifndef mmio_outsb
337 static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
338 {
339 	while (--count >= 0) {
340 		__raw_writeb(*src, addr);
341 		src++;
342 	}
343 }
344 static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
345 {
346 	while (--count >= 0) {
347 		__raw_writew(*src, addr);
348 		src++;
349 	}
350 }
351 static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
352 {
353 	while (--count >= 0) {
354 		__raw_writel(*src, addr);
355 		src++;
356 	}
357 }
358 #endif
359 
360 void ioread8_rep(const void __iomem *addr, void *dst, unsigned long count)
361 {
362 	IO_COND(addr, insb(port,dst,count), mmio_insb(addr, dst, count));
363 	/* KMSAN must treat values read from devices as initialized. */
364 	kmsan_unpoison_memory(dst, count);
365 }
366 void ioread16_rep(const void __iomem *addr, void *dst, unsigned long count)
367 {
368 	IO_COND(addr, insw(port,dst,count), mmio_insw(addr, dst, count));
369 	/* KMSAN must treat values read from devices as initialized. */
370 	kmsan_unpoison_memory(dst, count * 2);
371 }
372 void ioread32_rep(const void __iomem *addr, void *dst, unsigned long count)
373 {
374 	IO_COND(addr, insl(port,dst,count), mmio_insl(addr, dst, count));
375 	/* KMSAN must treat values read from devices as initialized. */
376 	kmsan_unpoison_memory(dst, count * 4);
377 }
378 EXPORT_SYMBOL(ioread8_rep);
379 EXPORT_SYMBOL(ioread16_rep);
380 EXPORT_SYMBOL(ioread32_rep);
381 
382 void iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
383 {
384 	/* Make sure uninitialized memory isn't copied to devices. */
385 	kmsan_check_memory(src, count);
386 	IO_COND(addr, outsb(port, src, count), mmio_outsb(addr, src, count));
387 }
388 void iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
389 {
390 	/* Make sure uninitialized memory isn't copied to devices. */
391 	kmsan_check_memory(src, count * 2);
392 	IO_COND(addr, outsw(port, src, count), mmio_outsw(addr, src, count));
393 }
394 void iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
395 {
396 	/* Make sure uninitialized memory isn't copied to devices. */
397 	kmsan_check_memory(src, count * 4);
398 	IO_COND(addr, outsl(port, src,count), mmio_outsl(addr, src, count));
399 }
400 EXPORT_SYMBOL(iowrite8_rep);
401 EXPORT_SYMBOL(iowrite16_rep);
402 EXPORT_SYMBOL(iowrite32_rep);
403 
404 #ifdef CONFIG_HAS_IOPORT_MAP
405 /* Create a virtual mapping cookie for an IO port range */
406 void __iomem *ioport_map(unsigned long port, unsigned int nr)
407 {
408 	if (port > PIO_MASK)
409 		return NULL;
410 	return (void __iomem *) (unsigned long) (port + PIO_OFFSET);
411 }
412 
413 void ioport_unmap(void __iomem *addr)
414 {
415 	/* Nothing to do */
416 }
417 EXPORT_SYMBOL(ioport_map);
418 EXPORT_SYMBOL(ioport_unmap);
419 #endif /* CONFIG_HAS_IOPORT_MAP */
420 
421 #ifdef CONFIG_PCI
422 /* Hide the details if this is a MMIO or PIO address space and just do what
423  * you expect in the correct way. */
424 void pci_iounmap(struct pci_dev *dev, void __iomem * addr)
425 {
426 	IO_COND(addr, /* nothing */, iounmap(addr));
427 }
428 EXPORT_SYMBOL(pci_iounmap);
429 #endif /* CONFIG_PCI */
430