xref: /openbmc/linux/arch/mips/mm/page.c (revision 99a15348)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org)
7  * Copyright (C) 2007  Maciej W. Rozycki
8  * Copyright (C) 2008  Thiemo Seufer
9  * Copyright (C) 2012  MIPS Technologies, Inc.
10  */
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/smp.h>
14 #include <linux/mm.h>
15 #include <linux/proc_fs.h>
16 
17 #include <asm/bugs.h>
18 #include <asm/cacheops.h>
19 #include <asm/cpu-type.h>
20 #include <asm/inst.h>
21 #include <asm/io.h>
22 #include <asm/page.h>
23 #include <asm/prefetch.h>
24 #include <asm/bootinfo.h>
25 #include <asm/mipsregs.h>
26 #include <asm/mmu_context.h>
27 #include <asm/cpu.h>
28 
29 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
30 #include <asm/sibyte/sb1250.h>
31 #include <asm/sibyte/sb1250_regs.h>
32 #include <asm/sibyte/sb1250_dma.h>
33 #endif
34 
35 #include <asm/uasm.h>
36 
37 /* Registers used in the assembled routines. */
38 #define ZERO 0
39 #define AT 2
40 #define A0 4
41 #define A1 5
42 #define A2 6
43 #define T0 8
44 #define T1 9
45 #define T2 10
46 #define T3 11
47 #define T9 25
48 #define RA 31
49 
50 /* Handle labels (which must be positive integers). */
51 enum label_id {
52 	label_clear_nopref = 1,
53 	label_clear_pref,
54 	label_copy_nopref,
55 	label_copy_pref_both,
56 	label_copy_pref_store,
57 };
58 
59 UASM_L_LA(_clear_nopref)
60 UASM_L_LA(_clear_pref)
61 UASM_L_LA(_copy_nopref)
62 UASM_L_LA(_copy_pref_both)
63 UASM_L_LA(_copy_pref_store)
64 
65 /* We need one branch and therefore one relocation per target label. */
66 static struct uasm_label labels[5];
67 static struct uasm_reloc relocs[5];
68 
69 #define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
70 #define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
71 
72 /*
73  * R6 has a limited offset of the pref instruction.
74  * Skip it if the offset is more than 9 bits.
75  */
76 #define _uasm_i_pref(a, b, c, d)		\
77 do {						\
78 	if (cpu_has_mips_r6) {			\
79 		if (c <= 0xff && c >= -0x100)	\
80 			uasm_i_pref(a, b, c, d);\
81 	} else {				\
82 		uasm_i_pref(a, b, c, d);	\
83 	}					\
84 } while(0)
85 
86 static int pref_bias_clear_store;
87 static int pref_bias_copy_load;
88 static int pref_bias_copy_store;
89 
90 static u32 pref_src_mode;
91 static u32 pref_dst_mode;
92 
93 static int clear_word_size;
94 static int copy_word_size;
95 
96 static int half_clear_loop_size;
97 static int half_copy_loop_size;
98 
99 static int cache_line_size;
100 #define cache_line_mask() (cache_line_size - 1)
101 
102 static inline void
103 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
104 {
105 	if (cpu_has_64bit_gp_regs &&
106 	    IS_ENABLED(CONFIG_CPU_DADDI_WORKAROUNDS) &&
107 	    r4k_daddiu_bug()) {
108 		if (off > 0x7fff) {
109 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
110 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
111 		} else
112 			uasm_i_addiu(buf, T9, ZERO, off);
113 		uasm_i_daddu(buf, reg1, reg2, T9);
114 	} else {
115 		if (off > 0x7fff) {
116 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
117 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
118 			UASM_i_ADDU(buf, reg1, reg2, T9);
119 		} else
120 			UASM_i_ADDIU(buf, reg1, reg2, off);
121 	}
122 }
123 
124 static void set_prefetch_parameters(void)
125 {
126 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
127 		clear_word_size = 8;
128 	else
129 		clear_word_size = 4;
130 
131 	if (cpu_has_64bit_gp_regs)
132 		copy_word_size = 8;
133 	else
134 		copy_word_size = 4;
135 
136 	/*
137 	 * The pref's used here are using "streaming" hints, which cause the
138 	 * copied data to be kicked out of the cache sooner.  A page copy often
139 	 * ends up copying a lot more data than is commonly used, so this seems
140 	 * to make sense in terms of reducing cache pollution, but I've no real
141 	 * performance data to back this up.
142 	 */
143 	if (cpu_has_prefetch) {
144 		/*
145 		 * XXX: Most prefetch bias values in here are based on
146 		 * guesswork.
147 		 */
148 		cache_line_size = cpu_dcache_line_size();
149 		switch (current_cpu_type()) {
150 		case CPU_R5500:
151 		case CPU_TX49XX:
152 			/* These processors only support the Pref_Load. */
153 			pref_bias_copy_load = 256;
154 			break;
155 
156 		case CPU_R10000:
157 		case CPU_R12000:
158 		case CPU_R14000:
159 		case CPU_R16000:
160 			/*
161 			 * Those values have been experimentally tuned for an
162 			 * Origin 200.
163 			 */
164 			pref_bias_clear_store = 512;
165 			pref_bias_copy_load = 256;
166 			pref_bias_copy_store = 256;
167 			pref_src_mode = Pref_LoadStreamed;
168 			pref_dst_mode = Pref_StoreStreamed;
169 			break;
170 
171 		case CPU_SB1:
172 		case CPU_SB1A:
173 			pref_bias_clear_store = 128;
174 			pref_bias_copy_load = 128;
175 			pref_bias_copy_store = 128;
176 			/*
177 			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
178 			 * hints are broken.
179 			 */
180 			if (current_cpu_type() == CPU_SB1 &&
181 			    (current_cpu_data.processor_id & 0xff) < 0x02) {
182 				pref_src_mode = Pref_Load;
183 				pref_dst_mode = Pref_Store;
184 			} else {
185 				pref_src_mode = Pref_LoadStreamed;
186 				pref_dst_mode = Pref_StoreStreamed;
187 			}
188 			break;
189 
190 		case CPU_LOONGSON64:
191 			/* Loongson-3 only support the Pref_Load/Pref_Store. */
192 			pref_bias_clear_store = 128;
193 			pref_bias_copy_load = 128;
194 			pref_bias_copy_store = 128;
195 			pref_src_mode = Pref_Load;
196 			pref_dst_mode = Pref_Store;
197 			break;
198 
199 		default:
200 			pref_bias_clear_store = 128;
201 			pref_bias_copy_load = 256;
202 			pref_bias_copy_store = 128;
203 			pref_src_mode = Pref_LoadStreamed;
204 			if (cpu_has_mips_r6)
205 				/*
206 				 * Bit 30 (Pref_PrepareForStore) has been
207 				 * removed from MIPS R6. Use bit 5
208 				 * (Pref_StoreStreamed).
209 				 */
210 				pref_dst_mode = Pref_StoreStreamed;
211 			else
212 				pref_dst_mode = Pref_PrepareForStore;
213 			break;
214 		}
215 	} else {
216 		if (cpu_has_cache_cdex_s)
217 			cache_line_size = cpu_scache_line_size();
218 		else if (cpu_has_cache_cdex_p)
219 			cache_line_size = cpu_dcache_line_size();
220 	}
221 	/*
222 	 * Too much unrolling will overflow the available space in
223 	 * clear_space_array / copy_page_array.
224 	 */
225 	half_clear_loop_size = min(16 * clear_word_size,
226 				   max(cache_line_size >> 1,
227 				       4 * clear_word_size));
228 	half_copy_loop_size = min(16 * copy_word_size,
229 				  max(cache_line_size >> 1,
230 				      4 * copy_word_size));
231 }
232 
233 static void build_clear_store(u32 **buf, int off)
234 {
235 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
236 		uasm_i_sd(buf, ZERO, off, A0);
237 	} else {
238 		uasm_i_sw(buf, ZERO, off, A0);
239 	}
240 }
241 
242 static inline void build_clear_pref(u32 **buf, int off)
243 {
244 	if (off & cache_line_mask())
245 		return;
246 
247 	if (pref_bias_clear_store) {
248 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
249 			    A0);
250 	} else if (cache_line_size == (half_clear_loop_size << 1)) {
251 		if (cpu_has_cache_cdex_s) {
252 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
253 		} else if (cpu_has_cache_cdex_p) {
254 			if (IS_ENABLED(CONFIG_WAR_R4600_V1_HIT_CACHEOP) &&
255 			    cpu_is_r4600_v1_x()) {
256 				uasm_i_nop(buf);
257 				uasm_i_nop(buf);
258 				uasm_i_nop(buf);
259 				uasm_i_nop(buf);
260 			}
261 
262 			if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) &&
263 			    cpu_is_r4600_v2_x())
264 				uasm_i_lw(buf, ZERO, ZERO, AT);
265 
266 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
267 		}
268 	}
269 }
270 
271 extern u32 __clear_page_start;
272 extern u32 __clear_page_end;
273 extern u32 __copy_page_start;
274 extern u32 __copy_page_end;
275 
276 void build_clear_page(void)
277 {
278 	int off;
279 	u32 *buf = &__clear_page_start;
280 	struct uasm_label *l = labels;
281 	struct uasm_reloc *r = relocs;
282 	int i;
283 	static atomic_t run_once = ATOMIC_INIT(0);
284 
285 	if (atomic_xchg(&run_once, 1)) {
286 		return;
287 	}
288 
289 	memset(labels, 0, sizeof(labels));
290 	memset(relocs, 0, sizeof(relocs));
291 
292 	set_prefetch_parameters();
293 
294 	/*
295 	 * This algorithm makes the following assumptions:
296 	 *   - The prefetch bias is a multiple of 2 words.
297 	 *   - The prefetch bias is less than one page.
298 	 */
299 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
300 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
301 
302 	off = PAGE_SIZE - pref_bias_clear_store;
303 	if (off > 0xffff || !pref_bias_clear_store)
304 		pg_addiu(&buf, A2, A0, off);
305 	else
306 		uasm_i_ori(&buf, A2, A0, off);
307 
308 	if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) && cpu_is_r4600_v2_x())
309 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
310 
311 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
312 				* cache_line_size : 0;
313 	while (off) {
314 		build_clear_pref(&buf, -off);
315 		off -= cache_line_size;
316 	}
317 	uasm_l_clear_pref(&l, buf);
318 	do {
319 		build_clear_pref(&buf, off);
320 		build_clear_store(&buf, off);
321 		off += clear_word_size;
322 	} while (off < half_clear_loop_size);
323 	pg_addiu(&buf, A0, A0, 2 * off);
324 	off = -off;
325 	do {
326 		build_clear_pref(&buf, off);
327 		if (off == -clear_word_size)
328 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
329 		build_clear_store(&buf, off);
330 		off += clear_word_size;
331 	} while (off < 0);
332 
333 	if (pref_bias_clear_store) {
334 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
335 		uasm_l_clear_nopref(&l, buf);
336 		off = 0;
337 		do {
338 			build_clear_store(&buf, off);
339 			off += clear_word_size;
340 		} while (off < half_clear_loop_size);
341 		pg_addiu(&buf, A0, A0, 2 * off);
342 		off = -off;
343 		do {
344 			if (off == -clear_word_size)
345 				uasm_il_bne(&buf, &r, A0, A2,
346 					    label_clear_nopref);
347 			build_clear_store(&buf, off);
348 			off += clear_word_size;
349 		} while (off < 0);
350 	}
351 
352 	uasm_i_jr(&buf, RA);
353 	uasm_i_nop(&buf);
354 
355 	BUG_ON(buf > &__clear_page_end);
356 
357 	uasm_resolve_relocs(relocs, labels);
358 
359 	pr_debug("Synthesized clear page handler (%u instructions).\n",
360 		 (u32)(buf - &__clear_page_start));
361 
362 	pr_debug("\t.set push\n");
363 	pr_debug("\t.set noreorder\n");
364 	for (i = 0; i < (buf - &__clear_page_start); i++)
365 		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
366 	pr_debug("\t.set pop\n");
367 }
368 
369 static void build_copy_load(u32 **buf, int reg, int off)
370 {
371 	if (cpu_has_64bit_gp_regs) {
372 		uasm_i_ld(buf, reg, off, A1);
373 	} else {
374 		uasm_i_lw(buf, reg, off, A1);
375 	}
376 }
377 
378 static void build_copy_store(u32 **buf, int reg, int off)
379 {
380 	if (cpu_has_64bit_gp_regs) {
381 		uasm_i_sd(buf, reg, off, A0);
382 	} else {
383 		uasm_i_sw(buf, reg, off, A0);
384 	}
385 }
386 
387 static inline void build_copy_load_pref(u32 **buf, int off)
388 {
389 	if (off & cache_line_mask())
390 		return;
391 
392 	if (pref_bias_copy_load)
393 		_uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
394 }
395 
396 static inline void build_copy_store_pref(u32 **buf, int off)
397 {
398 	if (off & cache_line_mask())
399 		return;
400 
401 	if (pref_bias_copy_store) {
402 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
403 			    A0);
404 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
405 		if (cpu_has_cache_cdex_s) {
406 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
407 		} else if (cpu_has_cache_cdex_p) {
408 			if (IS_ENABLED(CONFIG_WAR_R4600_V1_HIT_CACHEOP) &&
409 			    cpu_is_r4600_v1_x()) {
410 				uasm_i_nop(buf);
411 				uasm_i_nop(buf);
412 				uasm_i_nop(buf);
413 				uasm_i_nop(buf);
414 			}
415 
416 			if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) &&
417 			    cpu_is_r4600_v2_x())
418 				uasm_i_lw(buf, ZERO, ZERO, AT);
419 
420 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
421 		}
422 	}
423 }
424 
425 void build_copy_page(void)
426 {
427 	int off;
428 	u32 *buf = &__copy_page_start;
429 	struct uasm_label *l = labels;
430 	struct uasm_reloc *r = relocs;
431 	int i;
432 	static atomic_t run_once = ATOMIC_INIT(0);
433 
434 	if (atomic_xchg(&run_once, 1)) {
435 		return;
436 	}
437 
438 	memset(labels, 0, sizeof(labels));
439 	memset(relocs, 0, sizeof(relocs));
440 
441 	set_prefetch_parameters();
442 
443 	/*
444 	 * This algorithm makes the following assumptions:
445 	 *   - All prefetch biases are multiples of 8 words.
446 	 *   - The prefetch biases are less than one page.
447 	 *   - The store prefetch bias isn't greater than the load
448 	 *     prefetch bias.
449 	 */
450 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
451 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
452 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
453 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
454 
455 	off = PAGE_SIZE - pref_bias_copy_load;
456 	if (off > 0xffff || !pref_bias_copy_load)
457 		pg_addiu(&buf, A2, A0, off);
458 	else
459 		uasm_i_ori(&buf, A2, A0, off);
460 
461 	if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) && cpu_is_r4600_v2_x())
462 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
463 
464 	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
465 				cache_line_size : 0;
466 	while (off) {
467 		build_copy_load_pref(&buf, -off);
468 		off -= cache_line_size;
469 	}
470 	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
471 				cache_line_size : 0;
472 	while (off) {
473 		build_copy_store_pref(&buf, -off);
474 		off -= cache_line_size;
475 	}
476 	uasm_l_copy_pref_both(&l, buf);
477 	do {
478 		build_copy_load_pref(&buf, off);
479 		build_copy_load(&buf, T0, off);
480 		build_copy_load_pref(&buf, off + copy_word_size);
481 		build_copy_load(&buf, T1, off + copy_word_size);
482 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
483 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
484 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
485 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
486 		build_copy_store_pref(&buf, off);
487 		build_copy_store(&buf, T0, off);
488 		build_copy_store_pref(&buf, off + copy_word_size);
489 		build_copy_store(&buf, T1, off + copy_word_size);
490 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
491 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
492 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
493 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
494 		off += 4 * copy_word_size;
495 	} while (off < half_copy_loop_size);
496 	pg_addiu(&buf, A1, A1, 2 * off);
497 	pg_addiu(&buf, A0, A0, 2 * off);
498 	off = -off;
499 	do {
500 		build_copy_load_pref(&buf, off);
501 		build_copy_load(&buf, T0, off);
502 		build_copy_load_pref(&buf, off + copy_word_size);
503 		build_copy_load(&buf, T1, off + copy_word_size);
504 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
505 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
506 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
507 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
508 		build_copy_store_pref(&buf, off);
509 		build_copy_store(&buf, T0, off);
510 		build_copy_store_pref(&buf, off + copy_word_size);
511 		build_copy_store(&buf, T1, off + copy_word_size);
512 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
513 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
514 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
515 		if (off == -(4 * copy_word_size))
516 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
517 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
518 		off += 4 * copy_word_size;
519 	} while (off < 0);
520 
521 	if (pref_bias_copy_load - pref_bias_copy_store) {
522 		pg_addiu(&buf, A2, A0,
523 			 pref_bias_copy_load - pref_bias_copy_store);
524 		uasm_l_copy_pref_store(&l, buf);
525 		off = 0;
526 		do {
527 			build_copy_load(&buf, T0, off);
528 			build_copy_load(&buf, T1, off + copy_word_size);
529 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
530 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
531 			build_copy_store_pref(&buf, off);
532 			build_copy_store(&buf, T0, off);
533 			build_copy_store_pref(&buf, off + copy_word_size);
534 			build_copy_store(&buf, T1, off + copy_word_size);
535 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
536 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
537 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
538 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
539 			off += 4 * copy_word_size;
540 		} while (off < half_copy_loop_size);
541 		pg_addiu(&buf, A1, A1, 2 * off);
542 		pg_addiu(&buf, A0, A0, 2 * off);
543 		off = -off;
544 		do {
545 			build_copy_load(&buf, T0, off);
546 			build_copy_load(&buf, T1, off + copy_word_size);
547 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
548 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
549 			build_copy_store_pref(&buf, off);
550 			build_copy_store(&buf, T0, off);
551 			build_copy_store_pref(&buf, off + copy_word_size);
552 			build_copy_store(&buf, T1, off + copy_word_size);
553 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
554 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
555 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
556 			if (off == -(4 * copy_word_size))
557 				uasm_il_bne(&buf, &r, A2, A0,
558 					    label_copy_pref_store);
559 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
560 			off += 4 * copy_word_size;
561 		} while (off < 0);
562 	}
563 
564 	if (pref_bias_copy_store) {
565 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
566 		uasm_l_copy_nopref(&l, buf);
567 		off = 0;
568 		do {
569 			build_copy_load(&buf, T0, off);
570 			build_copy_load(&buf, T1, off + copy_word_size);
571 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
572 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
573 			build_copy_store(&buf, T0, off);
574 			build_copy_store(&buf, T1, off + copy_word_size);
575 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
576 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
577 			off += 4 * copy_word_size;
578 		} while (off < half_copy_loop_size);
579 		pg_addiu(&buf, A1, A1, 2 * off);
580 		pg_addiu(&buf, A0, A0, 2 * off);
581 		off = -off;
582 		do {
583 			build_copy_load(&buf, T0, off);
584 			build_copy_load(&buf, T1, off + copy_word_size);
585 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
586 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
587 			build_copy_store(&buf, T0, off);
588 			build_copy_store(&buf, T1, off + copy_word_size);
589 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
590 			if (off == -(4 * copy_word_size))
591 				uasm_il_bne(&buf, &r, A2, A0,
592 					    label_copy_nopref);
593 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
594 			off += 4 * copy_word_size;
595 		} while (off < 0);
596 	}
597 
598 	uasm_i_jr(&buf, RA);
599 	uasm_i_nop(&buf);
600 
601 	BUG_ON(buf > &__copy_page_end);
602 
603 	uasm_resolve_relocs(relocs, labels);
604 
605 	pr_debug("Synthesized copy page handler (%u instructions).\n",
606 		 (u32)(buf - &__copy_page_start));
607 
608 	pr_debug("\t.set push\n");
609 	pr_debug("\t.set noreorder\n");
610 	for (i = 0; i < (buf - &__copy_page_start); i++)
611 		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
612 	pr_debug("\t.set pop\n");
613 }
614 
615 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
616 extern void clear_page_cpu(void *page);
617 extern void copy_page_cpu(void *to, void *from);
618 
619 /*
620  * Pad descriptors to cacheline, since each is exclusively owned by a
621  * particular CPU.
622  */
623 struct dmadscr {
624 	u64 dscr_a;
625 	u64 dscr_b;
626 	u64 pad_a;
627 	u64 pad_b;
628 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
629 
630 void clear_page(void *page)
631 {
632 	u64 to_phys = CPHYSADDR((unsigned long)page);
633 	unsigned int cpu = smp_processor_id();
634 
635 	/* if the page is not in KSEG0, use old way */
636 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
637 		return clear_page_cpu(page);
638 
639 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
640 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
641 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
642 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
643 
644 	/*
645 	 * Don't really want to do it this way, but there's no
646 	 * reliable way to delay completion detection.
647 	 */
648 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
649 		 & M_DM_DSCR_BASE_INTERRUPT))
650 		;
651 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
652 }
653 EXPORT_SYMBOL(clear_page);
654 
655 void copy_page(void *to, void *from)
656 {
657 	u64 from_phys = CPHYSADDR((unsigned long)from);
658 	u64 to_phys = CPHYSADDR((unsigned long)to);
659 	unsigned int cpu = smp_processor_id();
660 
661 	/* if any page is not in KSEG0, use old way */
662 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
663 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
664 		return copy_page_cpu(to, from);
665 
666 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
667 				 M_DM_DSCRA_INTERRUPT;
668 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
669 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
670 
671 	/*
672 	 * Don't really want to do it this way, but there's no
673 	 * reliable way to delay completion detection.
674 	 */
675 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
676 		 & M_DM_DSCR_BASE_INTERRUPT))
677 		;
678 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
679 }
680 EXPORT_SYMBOL(copy_page);
681 
682 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
683