xref: /openbmc/linux/arch/parisc/lib/io.c (revision 9d4fa1a1) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/parisc/lib/io.c
4  *
5  * Copyright (c) Matthew Wilcox 2001 for Hewlett-Packard
6  * Copyright (c) Randolph Chung 2001 <tausq@debian.org>
7  *
8  * IO accessing functions which shouldn't be inlined because they're too big
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <asm/io.h>
14 
15 /* Copies a block of memory to a device in an efficient manner.
16  * Assumes the device can cope with 32-bit transfers.  If it can't,
17  * don't use this function.
18  */
19 void memcpy_toio(volatile void __iomem *dst, const void *src, int count)
20 {
21 	if (((unsigned long)dst & 3) != ((unsigned long)src & 3))
22 		goto bytecopy;
23 	while ((unsigned long)dst & 3) {
24 		writeb(*(char *)src, dst++);
25 		src++;
26 		count--;
27 	}
28 	while (count > 3) {
29 		__raw_writel(*(u32 *)src, dst);
30 		src += 4;
31 		dst += 4;
32 		count -= 4;
33 	}
34  bytecopy:
35 	while (count--) {
36 		writeb(*(char *)src, dst++);
37 		src++;
38 	}
39 }
40 
41 /*
42 ** Copies a block of memory from a device in an efficient manner.
43 ** Assumes the device can cope with 32-bit transfers.  If it can't,
44 ** don't use this function.
45 **
46 ** CR16 counts on C3000 reading 256 bytes from Symbios 896 RAM:
47 **	27341/64    = 427 cyc per int
48 **	61311/128   = 478 cyc per short
49 **	122637/256  = 479 cyc per byte
50 ** Ergo bus latencies dominant (not transfer size).
51 **      Minimize total number of transfers at cost of CPU cycles.
52 **	TODO: only look at src alignment and adjust the stores to dest.
53 */
54 void memcpy_fromio(void *dst, const volatile void __iomem *src, int count)
55 {
56 	/* first compare alignment of src/dst */
57 	if ( (((unsigned long)dst ^ (unsigned long)src) & 1) || (count < 2) )
58 		goto bytecopy;
59 
60 	if ( (((unsigned long)dst ^ (unsigned long)src) & 2) || (count < 4) )
61 		goto shortcopy;
62 
63 	/* Then check for misaligned start address */
64 	if ((unsigned long)src & 1) {
65 		*(u8 *)dst = readb(src);
66 		src++;
67 		dst++;
68 		count--;
69 		if (count < 2) goto bytecopy;
70 	}
71 
72 	if ((unsigned long)src & 2) {
73 		*(u16 *)dst = __raw_readw(src);
74 		src += 2;
75 		dst += 2;
76 		count -= 2;
77 	}
78 
79 	while (count > 3) {
80 		*(u32 *)dst = __raw_readl(src);
81 		dst += 4;
82 		src += 4;
83 		count -= 4;
84 	}
85 
86  shortcopy:
87 	while (count > 1) {
88 		*(u16 *)dst = __raw_readw(src);
89 		src += 2;
90 		dst += 2;
91 		count -= 2;
92 	}
93 
94  bytecopy:
95 	while (count--) {
96 		*(char *)dst = readb(src);
97 		src++;
98 		dst++;
99 	}
100 }
101 
102 /* Sets a block of memory on a device to a given value.
103  * Assumes the device can cope with 32-bit transfers.  If it can't,
104  * don't use this function.
105  */
106 void memset_io(volatile void __iomem *addr, unsigned char val, int count)
107 {
108 	u32 val32 = (val << 24) | (val << 16) | (val << 8) | val;
109 	while ((unsigned long)addr & 3) {
110 		writeb(val, addr++);
111 		count--;
112 	}
113 	while (count > 3) {
114 		__raw_writel(val32, addr);
115 		addr += 4;
116 		count -= 4;
117 	}
118 	while (count--) {
119 		writeb(val, addr++);
120 	}
121 }
122 
123 /*
124  * Read COUNT 8-bit bytes from port PORT into memory starting at
125  * SRC.
126  */
127 void insb (unsigned long port, void *dst, unsigned long count)
128 {
129 	unsigned char *p;
130 
131 	p = (unsigned char *)dst;
132 
133 	while (((unsigned long)p) & 0x3) {
134 		if (!count)
135 			return;
136 		count--;
137 		*p = inb(port);
138 		p++;
139 	}
140 
141 	while (count >= 4) {
142 		unsigned int w;
143 		count -= 4;
144 		w = inb(port) << 24;
145 		w |= inb(port) << 16;
146 		w |= inb(port) << 8;
147 		w |= inb(port);
148 		*(unsigned int *) p = w;
149 		p += 4;
150 	}
151 
152 	while (count) {
153 		--count;
154 		*p = inb(port);
155 		p++;
156 	}
157 }
158 
159 
160 /*
161  * Read COUNT 16-bit words from port PORT into memory starting at
162  * SRC.  SRC must be at least short aligned.  This is used by the
163  * IDE driver to read disk sectors.  Performance is important, but
164  * the interfaces seems to be slow: just using the inlined version
165  * of the inw() breaks things.
166  */
167 void insw (unsigned long port, void *dst, unsigned long count)
168 {
169 	unsigned int l = 0, l2;
170 	unsigned char *p;
171 
172 	p = (unsigned char *)dst;
173 
174 	if (!count)
175 		return;
176 
177 	switch (((unsigned long)p) & 0x3)
178 	{
179 	 case 0x00:			/* Buffer 32-bit aligned */
180 		while (count>=2) {
181 
182 			count -= 2;
183 			l = cpu_to_le16(inw(port)) << 16;
184 			l |= cpu_to_le16(inw(port));
185 			*(unsigned int *)p = l;
186 			p += 4;
187 		}
188 		if (count) {
189 			*(unsigned short *)p = cpu_to_le16(inw(port));
190 		}
191 		break;
192 
193 	 case 0x02:			/* Buffer 16-bit aligned */
194 		*(unsigned short *)p = cpu_to_le16(inw(port));
195 		p += 2;
196 		count--;
197 		while (count>=2) {
198 
199 			count -= 2;
200 			l = cpu_to_le16(inw(port)) << 16;
201 			l |= cpu_to_le16(inw(port));
202 			*(unsigned int *)p = l;
203 			p += 4;
204 		}
205 		if (count) {
206 			*(unsigned short *)p = cpu_to_le16(inw(port));
207 		}
208 		break;
209 
210 	 case 0x01:			/* Buffer 8-bit aligned */
211 	 case 0x03:
212 		/* I don't bother with 32bit transfers
213 		 * in this case, 16bit will have to do -- DE */
214 		--count;
215 
216 		l = cpu_to_le16(inw(port));
217 		*p = l >> 8;
218 		p++;
219 		while (count--)
220 		{
221 			l2 = cpu_to_le16(inw(port));
222 			*(unsigned short *)p = (l & 0xff) << 8 | (l2 >> 8);
223 			p += 2;
224 			l = l2;
225 		}
226 		*p = l & 0xff;
227 		break;
228 	}
229 }
230 
231 
232 
233 /*
234  * Read COUNT 32-bit words from port PORT into memory starting at
235  * SRC. Now works with any alignment in SRC. Performance is important,
236  * but the interfaces seems to be slow: just using the inlined version
237  * of the inl() breaks things.
238  */
239 void insl (unsigned long port, void *dst, unsigned long count)
240 {
241 	unsigned int l = 0, l2;
242 	unsigned char *p;
243 
244 	p = (unsigned char *)dst;
245 
246 	if (!count)
247 		return;
248 
249 	switch (((unsigned long) dst) & 0x3)
250 	{
251 	 case 0x00:			/* Buffer 32-bit aligned */
252 		while (count--)
253 		{
254 			*(unsigned int *)p = cpu_to_le32(inl(port));
255 			p += 4;
256 		}
257 		break;
258 
259 	 case 0x02:			/* Buffer 16-bit aligned */
260 		--count;
261 
262 		l = cpu_to_le32(inl(port));
263 		*(unsigned short *)p = l >> 16;
264 		p += 2;
265 
266 		while (count--)
267 		{
268 			l2 = cpu_to_le32(inl(port));
269 			*(unsigned int *)p = (l & 0xffff) << 16 | (l2 >> 16);
270 			p += 4;
271 			l = l2;
272 		}
273 		*(unsigned short *)p = l & 0xffff;
274 		break;
275 	 case 0x01:			/* Buffer 8-bit aligned */
276 		--count;
277 
278 		l = cpu_to_le32(inl(port));
279 		*(unsigned char *)p = l >> 24;
280 		p++;
281 		*(unsigned short *)p = (l >> 8) & 0xffff;
282 		p += 2;
283 		while (count--)
284 		{
285 			l2 = cpu_to_le32(inl(port));
286 			*(unsigned int *)p = (l & 0xff) << 24 | (l2 >> 8);
287 			p += 4;
288 			l = l2;
289 		}
290 		*p = l & 0xff;
291 		break;
292 	 case 0x03:			/* Buffer 8-bit aligned */
293 		--count;
294 
295 		l = cpu_to_le32(inl(port));
296 		*p = l >> 24;
297 		p++;
298 		while (count--)
299 		{
300 			l2 = cpu_to_le32(inl(port));
301 			*(unsigned int *)p = (l & 0xffffff) << 8 | l2 >> 24;
302 			p += 4;
303 			l = l2;
304 		}
305 		*(unsigned short *)p = (l >> 8) & 0xffff;
306 		p += 2;
307 		*p = l & 0xff;
308 		break;
309 	}
310 }
311 
312 
313 /*
314  * Like insb but in the opposite direction.
315  * Don't worry as much about doing aligned memory transfers:
316  * doing byte reads the "slow" way isn't nearly as slow as
317  * doing byte writes the slow way (no r-m-w cycle).
318  */
319 void outsb(unsigned long port, const void * src, unsigned long count)
320 {
321 	const unsigned char *p;
322 
323 	p = (const unsigned char *)src;
324 	while (count) {
325 		count--;
326 		outb(*p, port);
327 		p++;
328 	}
329 }
330 
331 /*
332  * Like insw but in the opposite direction.  This is used by the IDE
333  * driver to write disk sectors.  Performance is important, but the
334  * interfaces seems to be slow: just using the inlined version of the
335  * outw() breaks things.
336  */
337 void outsw (unsigned long port, const void *src, unsigned long count)
338 {
339 	unsigned int l = 0, l2;
340 	const unsigned char *p;
341 
342 	p = (const unsigned char *)src;
343 
344 	if (!count)
345 		return;
346 
347 	switch (((unsigned long)p) & 0x3)
348 	{
349 	 case 0x00:			/* Buffer 32-bit aligned */
350 		while (count>=2) {
351 			count -= 2;
352 			l = *(unsigned int *)p;
353 			p += 4;
354 			outw(le16_to_cpu(l >> 16), port);
355 			outw(le16_to_cpu(l & 0xffff), port);
356 		}
357 		if (count) {
358 			outw(le16_to_cpu(*(unsigned short*)p), port);
359 		}
360 		break;
361 
362 	 case 0x02:			/* Buffer 16-bit aligned */
363 
364 		outw(le16_to_cpu(*(unsigned short*)p), port);
365 		p += 2;
366 		count--;
367 
368 		while (count>=2) {
369 			count -= 2;
370 			l = *(unsigned int *)p;
371 			p += 4;
372 			outw(le16_to_cpu(l >> 16), port);
373 			outw(le16_to_cpu(l & 0xffff), port);
374 		}
375 		if (count) {
376 			outw(le16_to_cpu(*(unsigned short *)p), port);
377 		}
378 		break;
379 
380 	 case 0x01:			/* Buffer 8-bit aligned */
381 		/* I don't bother with 32bit transfers
382 		 * in this case, 16bit will have to do -- DE */
383 
384 		l  = *p << 8;
385 		p++;
386 		count--;
387 		while (count)
388 		{
389 			count--;
390 			l2 = *(unsigned short *)p;
391 			p += 2;
392 			outw(le16_to_cpu(l | l2 >> 8), port);
393 		        l = l2 << 8;
394 		}
395 		l2 = *(unsigned char *)p;
396 		outw (le16_to_cpu(l | l2>>8), port);
397 		break;
398 
399 	}
400 }
401 
402 
403 /*
404  * Like insl but in the opposite direction.  This is used by the IDE
405  * driver to write disk sectors.  Works with any alignment in SRC.
406  *  Performance is important, but the interfaces seems to be slow:
407  * just using the inlined version of the outl() breaks things.
408  */
409 void outsl (unsigned long port, const void *src, unsigned long count)
410 {
411 	unsigned int l = 0, l2;
412 	const unsigned char *p;
413 
414 	p = (const unsigned char *)src;
415 
416 	if (!count)
417 		return;
418 
419 	switch (((unsigned long)p) & 0x3)
420 	{
421 	 case 0x00:			/* Buffer 32-bit aligned */
422 		while (count--)
423 		{
424 			outl(le32_to_cpu(*(unsigned int *)p), port);
425 			p += 4;
426 		}
427 		break;
428 
429 	 case 0x02:			/* Buffer 16-bit aligned */
430 		--count;
431 
432 		l = *(unsigned short *)p;
433 		p += 2;
434 
435 		while (count--)
436 		{
437 			l2 = *(unsigned int *)p;
438 			p += 4;
439 			outl (le32_to_cpu(l << 16 | l2 >> 16), port);
440 			l = l2;
441 		}
442 		l2 = *(unsigned short *)p;
443 		outl (le32_to_cpu(l << 16 | l2), port);
444 		break;
445 	 case 0x01:			/* Buffer 8-bit aligned */
446 		--count;
447 
448 		l = *p << 24;
449 		p++;
450 		l |= *(unsigned short *)p << 8;
451 		p += 2;
452 
453 		while (count--)
454 		{
455 			l2 = *(unsigned int *)p;
456 			p += 4;
457 			outl (le32_to_cpu(l | l2 >> 24), port);
458 			l = l2 << 8;
459 		}
460 		l2 = *p;
461 		outl (le32_to_cpu(l | l2), port);
462 		break;
463 	 case 0x03:			/* Buffer 8-bit aligned */
464 		--count;
465 
466 		l = *p << 24;
467 		p++;
468 
469 		while (count--)
470 		{
471 			l2 = *(unsigned int *)p;
472 			p += 4;
473 			outl (le32_to_cpu(l | l2 >> 8), port);
474 			l = l2 << 24;
475 		}
476 		l2 = *(unsigned short *)p << 16;
477 		p += 2;
478 		l2 |= *p;
479 		outl (le32_to_cpu(l | l2), port);
480 		break;
481 	}
482 }
483 
484 EXPORT_SYMBOL(insb);
485 EXPORT_SYMBOL(insw);
486 EXPORT_SYMBOL(insl);
487 EXPORT_SYMBOL(outsb);
488 EXPORT_SYMBOL(outsw);
489 EXPORT_SYMBOL(outsl);
490