xref: /linux/arch/mips/mm/page.c (revision 83bce9c2baa51e439480a713119a73d3c8b61083)
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/pgtable.h>
24 #include <asm/prefetch.h>
25 #include <asm/bootinfo.h>
26 #include <asm/mipsregs.h>
27 #include <asm/mmu_context.h>
28 #include <asm/cpu.h>
29 #include <asm/war.h>
30 
31 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
32 #include <asm/sibyte/sb1250.h>
33 #include <asm/sibyte/sb1250_regs.h>
34 #include <asm/sibyte/sb1250_dma.h>
35 #endif
36 
37 #include <asm/uasm.h>
38 
39 /* Registers used in the assembled routines. */
40 #define ZERO 0
41 #define AT 2
42 #define A0 4
43 #define A1 5
44 #define A2 6
45 #define T0 8
46 #define T1 9
47 #define T2 10
48 #define T3 11
49 #define T9 25
50 #define RA 31
51 
52 /* Handle labels (which must be positive integers). */
53 enum label_id {
54 	label_clear_nopref = 1,
55 	label_clear_pref,
56 	label_copy_nopref,
57 	label_copy_pref_both,
58 	label_copy_pref_store,
59 };
60 
61 UASM_L_LA(_clear_nopref)
62 UASM_L_LA(_clear_pref)
63 UASM_L_LA(_copy_nopref)
64 UASM_L_LA(_copy_pref_both)
65 UASM_L_LA(_copy_pref_store)
66 
67 /* We need one branch and therefore one relocation per target label. */
68 static struct uasm_label labels[5];
69 static struct uasm_reloc relocs[5];
70 
71 #define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
72 #define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
73 
74 /*
75  * R6 has a limited offset of the pref instruction.
76  * Skip it if the offset is more than 9 bits.
77  */
78 #define _uasm_i_pref(a, b, c, d)		\
79 do {						\
80 	if (cpu_has_mips_r6) {			\
81 		if (c <= 0xff && c >= -0x100)	\
82 			uasm_i_pref(a, b, c, d);\
83 	} else {				\
84 		uasm_i_pref(a, b, c, d);	\
85 	}					\
86 } while(0)
87 
88 static int pref_bias_clear_store;
89 static int pref_bias_copy_load;
90 static int pref_bias_copy_store;
91 
92 static u32 pref_src_mode;
93 static u32 pref_dst_mode;
94 
95 static int clear_word_size;
96 static int copy_word_size;
97 
98 static int half_clear_loop_size;
99 static int half_copy_loop_size;
100 
101 static int cache_line_size;
102 #define cache_line_mask() (cache_line_size - 1)
103 
104 static inline void
105 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
106 {
107 	if (cpu_has_64bit_gp_regs && DADDI_WAR && 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_LOONGSON3:
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 (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
255 				uasm_i_nop(buf);
256 				uasm_i_nop(buf);
257 				uasm_i_nop(buf);
258 				uasm_i_nop(buf);
259 			}
260 
261 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
262 				uasm_i_lw(buf, ZERO, ZERO, AT);
263 
264 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
265 		}
266 	}
267 }
268 
269 extern u32 __clear_page_start;
270 extern u32 __clear_page_end;
271 extern u32 __copy_page_start;
272 extern u32 __copy_page_end;
273 
274 void build_clear_page(void)
275 {
276 	int off;
277 	u32 *buf = &__clear_page_start;
278 	struct uasm_label *l = labels;
279 	struct uasm_reloc *r = relocs;
280 	int i;
281 	static atomic_t run_once = ATOMIC_INIT(0);
282 
283 	if (atomic_xchg(&run_once, 1)) {
284 		return;
285 	}
286 
287 	memset(labels, 0, sizeof(labels));
288 	memset(relocs, 0, sizeof(relocs));
289 
290 	set_prefetch_parameters();
291 
292 	/*
293 	 * This algorithm makes the following assumptions:
294 	 *   - The prefetch bias is a multiple of 2 words.
295 	 *   - The prefetch bias is less than one page.
296 	 */
297 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
298 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
299 
300 	off = PAGE_SIZE - pref_bias_clear_store;
301 	if (off > 0xffff || !pref_bias_clear_store)
302 		pg_addiu(&buf, A2, A0, off);
303 	else
304 		uasm_i_ori(&buf, A2, A0, off);
305 
306 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
307 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
308 
309 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
310 				* cache_line_size : 0;
311 	while (off) {
312 		build_clear_pref(&buf, -off);
313 		off -= cache_line_size;
314 	}
315 	uasm_l_clear_pref(&l, buf);
316 	do {
317 		build_clear_pref(&buf, off);
318 		build_clear_store(&buf, off);
319 		off += clear_word_size;
320 	} while (off < half_clear_loop_size);
321 	pg_addiu(&buf, A0, A0, 2 * off);
322 	off = -off;
323 	do {
324 		build_clear_pref(&buf, off);
325 		if (off == -clear_word_size)
326 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
327 		build_clear_store(&buf, off);
328 		off += clear_word_size;
329 	} while (off < 0);
330 
331 	if (pref_bias_clear_store) {
332 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
333 		uasm_l_clear_nopref(&l, buf);
334 		off = 0;
335 		do {
336 			build_clear_store(&buf, off);
337 			off += clear_word_size;
338 		} while (off < half_clear_loop_size);
339 		pg_addiu(&buf, A0, A0, 2 * off);
340 		off = -off;
341 		do {
342 			if (off == -clear_word_size)
343 				uasm_il_bne(&buf, &r, A0, A2,
344 					    label_clear_nopref);
345 			build_clear_store(&buf, off);
346 			off += clear_word_size;
347 		} while (off < 0);
348 	}
349 
350 	uasm_i_jr(&buf, RA);
351 	uasm_i_nop(&buf);
352 
353 	BUG_ON(buf > &__clear_page_end);
354 
355 	uasm_resolve_relocs(relocs, labels);
356 
357 	pr_debug("Synthesized clear page handler (%u instructions).\n",
358 		 (u32)(buf - &__clear_page_start));
359 
360 	pr_debug("\t.set push\n");
361 	pr_debug("\t.set noreorder\n");
362 	for (i = 0; i < (buf - &__clear_page_start); i++)
363 		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
364 	pr_debug("\t.set pop\n");
365 }
366 
367 static void build_copy_load(u32 **buf, int reg, int off)
368 {
369 	if (cpu_has_64bit_gp_regs) {
370 		uasm_i_ld(buf, reg, off, A1);
371 	} else {
372 		uasm_i_lw(buf, reg, off, A1);
373 	}
374 }
375 
376 static void build_copy_store(u32 **buf, int reg, int off)
377 {
378 	if (cpu_has_64bit_gp_regs) {
379 		uasm_i_sd(buf, reg, off, A0);
380 	} else {
381 		uasm_i_sw(buf, reg, off, A0);
382 	}
383 }
384 
385 static inline void build_copy_load_pref(u32 **buf, int off)
386 {
387 	if (off & cache_line_mask())
388 		return;
389 
390 	if (pref_bias_copy_load)
391 		_uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
392 }
393 
394 static inline void build_copy_store_pref(u32 **buf, int off)
395 {
396 	if (off & cache_line_mask())
397 		return;
398 
399 	if (pref_bias_copy_store) {
400 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
401 			    A0);
402 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
403 		if (cpu_has_cache_cdex_s) {
404 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
405 		} else if (cpu_has_cache_cdex_p) {
406 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
407 				uasm_i_nop(buf);
408 				uasm_i_nop(buf);
409 				uasm_i_nop(buf);
410 				uasm_i_nop(buf);
411 			}
412 
413 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
414 				uasm_i_lw(buf, ZERO, ZERO, AT);
415 
416 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
417 		}
418 	}
419 }
420 
421 void build_copy_page(void)
422 {
423 	int off;
424 	u32 *buf = &__copy_page_start;
425 	struct uasm_label *l = labels;
426 	struct uasm_reloc *r = relocs;
427 	int i;
428 	static atomic_t run_once = ATOMIC_INIT(0);
429 
430 	if (atomic_xchg(&run_once, 1)) {
431 		return;
432 	}
433 
434 	memset(labels, 0, sizeof(labels));
435 	memset(relocs, 0, sizeof(relocs));
436 
437 	set_prefetch_parameters();
438 
439 	/*
440 	 * This algorithm makes the following assumptions:
441 	 *   - All prefetch biases are multiples of 8 words.
442 	 *   - The prefetch biases are less than one page.
443 	 *   - The store prefetch bias isn't greater than the load
444 	 *     prefetch bias.
445 	 */
446 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
447 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
448 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
449 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
450 
451 	off = PAGE_SIZE - pref_bias_copy_load;
452 	if (off > 0xffff || !pref_bias_copy_load)
453 		pg_addiu(&buf, A2, A0, off);
454 	else
455 		uasm_i_ori(&buf, A2, A0, off);
456 
457 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
458 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
459 
460 	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
461 				cache_line_size : 0;
462 	while (off) {
463 		build_copy_load_pref(&buf, -off);
464 		off -= cache_line_size;
465 	}
466 	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
467 				cache_line_size : 0;
468 	while (off) {
469 		build_copy_store_pref(&buf, -off);
470 		off -= cache_line_size;
471 	}
472 	uasm_l_copy_pref_both(&l, buf);
473 	do {
474 		build_copy_load_pref(&buf, off);
475 		build_copy_load(&buf, T0, off);
476 		build_copy_load_pref(&buf, off + copy_word_size);
477 		build_copy_load(&buf, T1, off + copy_word_size);
478 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
479 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
480 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
481 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
482 		build_copy_store_pref(&buf, off);
483 		build_copy_store(&buf, T0, off);
484 		build_copy_store_pref(&buf, off + copy_word_size);
485 		build_copy_store(&buf, T1, off + copy_word_size);
486 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
487 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
488 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
489 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
490 		off += 4 * copy_word_size;
491 	} while (off < half_copy_loop_size);
492 	pg_addiu(&buf, A1, A1, 2 * off);
493 	pg_addiu(&buf, A0, A0, 2 * off);
494 	off = -off;
495 	do {
496 		build_copy_load_pref(&buf, off);
497 		build_copy_load(&buf, T0, off);
498 		build_copy_load_pref(&buf, off + copy_word_size);
499 		build_copy_load(&buf, T1, off + copy_word_size);
500 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
501 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
502 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
503 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
504 		build_copy_store_pref(&buf, off);
505 		build_copy_store(&buf, T0, off);
506 		build_copy_store_pref(&buf, off + copy_word_size);
507 		build_copy_store(&buf, T1, off + copy_word_size);
508 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
509 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
510 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
511 		if (off == -(4 * copy_word_size))
512 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
513 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
514 		off += 4 * copy_word_size;
515 	} while (off < 0);
516 
517 	if (pref_bias_copy_load - pref_bias_copy_store) {
518 		pg_addiu(&buf, A2, A0,
519 			 pref_bias_copy_load - pref_bias_copy_store);
520 		uasm_l_copy_pref_store(&l, buf);
521 		off = 0;
522 		do {
523 			build_copy_load(&buf, T0, off);
524 			build_copy_load(&buf, T1, off + copy_word_size);
525 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
526 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
527 			build_copy_store_pref(&buf, off);
528 			build_copy_store(&buf, T0, off);
529 			build_copy_store_pref(&buf, off + copy_word_size);
530 			build_copy_store(&buf, T1, off + copy_word_size);
531 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
532 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
533 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
534 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
535 			off += 4 * copy_word_size;
536 		} while (off < half_copy_loop_size);
537 		pg_addiu(&buf, A1, A1, 2 * off);
538 		pg_addiu(&buf, A0, A0, 2 * off);
539 		off = -off;
540 		do {
541 			build_copy_load(&buf, T0, off);
542 			build_copy_load(&buf, T1, off + copy_word_size);
543 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
544 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
545 			build_copy_store_pref(&buf, off);
546 			build_copy_store(&buf, T0, off);
547 			build_copy_store_pref(&buf, off + copy_word_size);
548 			build_copy_store(&buf, T1, off + copy_word_size);
549 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
550 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
551 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
552 			if (off == -(4 * copy_word_size))
553 				uasm_il_bne(&buf, &r, A2, A0,
554 					    label_copy_pref_store);
555 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
556 			off += 4 * copy_word_size;
557 		} while (off < 0);
558 	}
559 
560 	if (pref_bias_copy_store) {
561 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
562 		uasm_l_copy_nopref(&l, buf);
563 		off = 0;
564 		do {
565 			build_copy_load(&buf, T0, off);
566 			build_copy_load(&buf, T1, off + copy_word_size);
567 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
568 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
569 			build_copy_store(&buf, T0, off);
570 			build_copy_store(&buf, T1, off + copy_word_size);
571 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
572 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
573 			off += 4 * copy_word_size;
574 		} while (off < half_copy_loop_size);
575 		pg_addiu(&buf, A1, A1, 2 * off);
576 		pg_addiu(&buf, A0, A0, 2 * off);
577 		off = -off;
578 		do {
579 			build_copy_load(&buf, T0, off);
580 			build_copy_load(&buf, T1, off + copy_word_size);
581 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
582 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
583 			build_copy_store(&buf, T0, off);
584 			build_copy_store(&buf, T1, off + copy_word_size);
585 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
586 			if (off == -(4 * copy_word_size))
587 				uasm_il_bne(&buf, &r, A2, A0,
588 					    label_copy_nopref);
589 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
590 			off += 4 * copy_word_size;
591 		} while (off < 0);
592 	}
593 
594 	uasm_i_jr(&buf, RA);
595 	uasm_i_nop(&buf);
596 
597 	BUG_ON(buf > &__copy_page_end);
598 
599 	uasm_resolve_relocs(relocs, labels);
600 
601 	pr_debug("Synthesized copy page handler (%u instructions).\n",
602 		 (u32)(buf - &__copy_page_start));
603 
604 	pr_debug("\t.set push\n");
605 	pr_debug("\t.set noreorder\n");
606 	for (i = 0; i < (buf - &__copy_page_start); i++)
607 		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
608 	pr_debug("\t.set pop\n");
609 }
610 
611 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
612 extern void clear_page_cpu(void *page);
613 extern void copy_page_cpu(void *to, void *from);
614 
615 /*
616  * Pad descriptors to cacheline, since each is exclusively owned by a
617  * particular CPU.
618  */
619 struct dmadscr {
620 	u64 dscr_a;
621 	u64 dscr_b;
622 	u64 pad_a;
623 	u64 pad_b;
624 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
625 
626 void sb1_dma_init(void)
627 {
628 	int i;
629 
630 	for (i = 0; i < DM_NUM_CHANNELS; i++) {
631 		const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
632 				     V_DM_DSCR_BASE_RINGSZ(1);
633 		void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
634 
635 		__raw_writeq(base_val, base_reg);
636 		__raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
637 		__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
638 	}
639 }
640 
641 void clear_page(void *page)
642 {
643 	u64 to_phys = CPHYSADDR((unsigned long)page);
644 	unsigned int cpu = smp_processor_id();
645 
646 	/* if the page is not in KSEG0, use old way */
647 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
648 		return clear_page_cpu(page);
649 
650 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
651 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
652 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
653 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
654 
655 	/*
656 	 * Don't really want to do it this way, but there's no
657 	 * reliable way to delay completion detection.
658 	 */
659 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
660 		 & M_DM_DSCR_BASE_INTERRUPT))
661 		;
662 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
663 }
664 EXPORT_SYMBOL(clear_page);
665 
666 void copy_page(void *to, void *from)
667 {
668 	u64 from_phys = CPHYSADDR((unsigned long)from);
669 	u64 to_phys = CPHYSADDR((unsigned long)to);
670 	unsigned int cpu = smp_processor_id();
671 
672 	/* if any page is not in KSEG0, use old way */
673 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
674 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
675 		return copy_page_cpu(to, from);
676 
677 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
678 				 M_DM_DSCRA_INTERRUPT;
679 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
680 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
681 
682 	/*
683 	 * Don't really want to do it this way, but there's no
684 	 * reliable way to delay completion detection.
685 	 */
686 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
687 		 & M_DM_DSCR_BASE_INTERRUPT))
688 		;
689 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
690 }
691 EXPORT_SYMBOL(copy_page);
692 
693 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
694