xref: /openbmc/linux/arch/mips/mm/page.c (revision 7587eb18)
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/module.h>
16 #include <linux/proc_fs.h>
17 
18 #include <asm/bugs.h>
19 #include <asm/cacheops.h>
20 #include <asm/cpu-type.h>
21 #include <asm/inst.h>
22 #include <asm/io.h>
23 #include <asm/page.h>
24 #include <asm/pgtable.h>
25 #include <asm/prefetch.h>
26 #include <asm/bootinfo.h>
27 #include <asm/mipsregs.h>
28 #include <asm/mmu_context.h>
29 #include <asm/cpu.h>
30 #include <asm/war.h>
31 
32 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
33 #include <asm/sibyte/sb1250.h>
34 #include <asm/sibyte/sb1250_regs.h>
35 #include <asm/sibyte/sb1250_dma.h>
36 #endif
37 
38 #include <asm/uasm.h>
39 
40 /* Registers used in the assembled routines. */
41 #define ZERO 0
42 #define AT 2
43 #define A0 4
44 #define A1 5
45 #define A2 6
46 #define T0 8
47 #define T1 9
48 #define T2 10
49 #define T3 11
50 #define T9 25
51 #define RA 31
52 
53 /* Handle labels (which must be positive integers). */
54 enum label_id {
55 	label_clear_nopref = 1,
56 	label_clear_pref,
57 	label_copy_nopref,
58 	label_copy_pref_both,
59 	label_copy_pref_store,
60 };
61 
62 UASM_L_LA(_clear_nopref)
63 UASM_L_LA(_clear_pref)
64 UASM_L_LA(_copy_nopref)
65 UASM_L_LA(_copy_pref_both)
66 UASM_L_LA(_copy_pref_store)
67 
68 /* We need one branch and therefore one relocation per target label. */
69 static struct uasm_label labels[5];
70 static struct uasm_reloc relocs[5];
71 
72 #define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
73 #define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
74 
75 /*
76  * R6 has a limited offset of the pref instruction.
77  * Skip it if the offset is more than 9 bits.
78  */
79 #define _uasm_i_pref(a, b, c, d)		\
80 do {						\
81 	if (cpu_has_mips_r6) {			\
82 		if (c <= 0xff && c >= -0x100)	\
83 			uasm_i_pref(a, b, c, d);\
84 	} else {				\
85 		uasm_i_pref(a, b, c, d);	\
86 	}					\
87 } while(0)
88 
89 static int pref_bias_clear_store;
90 static int pref_bias_copy_load;
91 static int pref_bias_copy_store;
92 
93 static u32 pref_src_mode;
94 static u32 pref_dst_mode;
95 
96 static int clear_word_size;
97 static int copy_word_size;
98 
99 static int half_clear_loop_size;
100 static int half_copy_loop_size;
101 
102 static int cache_line_size;
103 #define cache_line_mask() (cache_line_size - 1)
104 
105 static inline void
106 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
107 {
108 	if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
109 		if (off > 0x7fff) {
110 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
111 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
112 		} else
113 			uasm_i_addiu(buf, T9, ZERO, off);
114 		uasm_i_daddu(buf, reg1, reg2, T9);
115 	} else {
116 		if (off > 0x7fff) {
117 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
118 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
119 			UASM_i_ADDU(buf, reg1, reg2, T9);
120 		} else
121 			UASM_i_ADDIU(buf, reg1, reg2, off);
122 	}
123 }
124 
125 static void set_prefetch_parameters(void)
126 {
127 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
128 		clear_word_size = 8;
129 	else
130 		clear_word_size = 4;
131 
132 	if (cpu_has_64bit_gp_regs)
133 		copy_word_size = 8;
134 	else
135 		copy_word_size = 4;
136 
137 	/*
138 	 * The pref's used here are using "streaming" hints, which cause the
139 	 * copied data to be kicked out of the cache sooner.  A page copy often
140 	 * ends up copying a lot more data than is commonly used, so this seems
141 	 * to make sense in terms of reducing cache pollution, but I've no real
142 	 * performance data to back this up.
143 	 */
144 	if (cpu_has_prefetch) {
145 		/*
146 		 * XXX: Most prefetch bias values in here are based on
147 		 * guesswork.
148 		 */
149 		cache_line_size = cpu_dcache_line_size();
150 		switch (current_cpu_type()) {
151 		case CPU_R5500:
152 		case CPU_TX49XX:
153 			/* These processors only support the Pref_Load. */
154 			pref_bias_copy_load = 256;
155 			break;
156 
157 		case CPU_R10000:
158 		case CPU_R12000:
159 		case CPU_R14000:
160 		case CPU_R16000:
161 			/*
162 			 * Those values have been experimentally tuned for an
163 			 * Origin 200.
164 			 */
165 			pref_bias_clear_store = 512;
166 			pref_bias_copy_load = 256;
167 			pref_bias_copy_store = 256;
168 			pref_src_mode = Pref_LoadStreamed;
169 			pref_dst_mode = Pref_StoreStreamed;
170 			break;
171 
172 		case CPU_SB1:
173 		case CPU_SB1A:
174 			pref_bias_clear_store = 128;
175 			pref_bias_copy_load = 128;
176 			pref_bias_copy_store = 128;
177 			/*
178 			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
179 			 * hints are broken.
180 			 */
181 			if (current_cpu_type() == CPU_SB1 &&
182 			    (current_cpu_data.processor_id & 0xff) < 0x02) {
183 				pref_src_mode = Pref_Load;
184 				pref_dst_mode = Pref_Store;
185 			} else {
186 				pref_src_mode = Pref_LoadStreamed;
187 				pref_dst_mode = Pref_StoreStreamed;
188 			}
189 			break;
190 
191 		case CPU_LOONGSON3:
192 			/* Loongson-3 only support the Pref_Load/Pref_Store. */
193 			pref_bias_clear_store = 128;
194 			pref_bias_copy_load = 128;
195 			pref_bias_copy_store = 128;
196 			pref_src_mode = Pref_Load;
197 			pref_dst_mode = Pref_Store;
198 			break;
199 
200 		default:
201 			pref_bias_clear_store = 128;
202 			pref_bias_copy_load = 256;
203 			pref_bias_copy_store = 128;
204 			pref_src_mode = Pref_LoadStreamed;
205 			if (cpu_has_mips_r6)
206 				/*
207 				 * Bit 30 (Pref_PrepareForStore) has been
208 				 * removed from MIPS R6. Use bit 5
209 				 * (Pref_StoreStreamed).
210 				 */
211 				pref_dst_mode = Pref_StoreStreamed;
212 			else
213 				pref_dst_mode = Pref_PrepareForStore;
214 			break;
215 		}
216 	} else {
217 		if (cpu_has_cache_cdex_s)
218 			cache_line_size = cpu_scache_line_size();
219 		else if (cpu_has_cache_cdex_p)
220 			cache_line_size = cpu_dcache_line_size();
221 	}
222 	/*
223 	 * Too much unrolling will overflow the available space in
224 	 * clear_space_array / copy_page_array.
225 	 */
226 	half_clear_loop_size = min(16 * clear_word_size,
227 				   max(cache_line_size >> 1,
228 				       4 * clear_word_size));
229 	half_copy_loop_size = min(16 * copy_word_size,
230 				  max(cache_line_size >> 1,
231 				      4 * copy_word_size));
232 }
233 
234 static void build_clear_store(u32 **buf, int off)
235 {
236 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
237 		uasm_i_sd(buf, ZERO, off, A0);
238 	} else {
239 		uasm_i_sw(buf, ZERO, off, A0);
240 	}
241 }
242 
243 static inline void build_clear_pref(u32 **buf, int off)
244 {
245 	if (off & cache_line_mask())
246 		return;
247 
248 	if (pref_bias_clear_store) {
249 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
250 			    A0);
251 	} else if (cache_line_size == (half_clear_loop_size << 1)) {
252 		if (cpu_has_cache_cdex_s) {
253 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
254 		} else if (cpu_has_cache_cdex_p) {
255 			if (R4600_V1_HIT_CACHEOP_WAR && 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 (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
263 				uasm_i_lw(buf, ZERO, ZERO, AT);
264 
265 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
266 		}
267 	}
268 }
269 
270 extern u32 __clear_page_start;
271 extern u32 __clear_page_end;
272 extern u32 __copy_page_start;
273 extern u32 __copy_page_end;
274 
275 void build_clear_page(void)
276 {
277 	int off;
278 	u32 *buf = &__clear_page_start;
279 	struct uasm_label *l = labels;
280 	struct uasm_reloc *r = relocs;
281 	int i;
282 	static atomic_t run_once = ATOMIC_INIT(0);
283 
284 	if (atomic_xchg(&run_once, 1)) {
285 		return;
286 	}
287 
288 	memset(labels, 0, sizeof(labels));
289 	memset(relocs, 0, sizeof(relocs));
290 
291 	set_prefetch_parameters();
292 
293 	/*
294 	 * This algorithm makes the following assumptions:
295 	 *   - The prefetch bias is a multiple of 2 words.
296 	 *   - The prefetch bias is less than one page.
297 	 */
298 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
299 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
300 
301 	off = PAGE_SIZE - pref_bias_clear_store;
302 	if (off > 0xffff || !pref_bias_clear_store)
303 		pg_addiu(&buf, A2, A0, off);
304 	else
305 		uasm_i_ori(&buf, A2, A0, off);
306 
307 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
308 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
309 
310 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
311 				* cache_line_size : 0;
312 	while (off) {
313 		build_clear_pref(&buf, -off);
314 		off -= cache_line_size;
315 	}
316 	uasm_l_clear_pref(&l, buf);
317 	do {
318 		build_clear_pref(&buf, off);
319 		build_clear_store(&buf, off);
320 		off += clear_word_size;
321 	} while (off < half_clear_loop_size);
322 	pg_addiu(&buf, A0, A0, 2 * off);
323 	off = -off;
324 	do {
325 		build_clear_pref(&buf, off);
326 		if (off == -clear_word_size)
327 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
328 		build_clear_store(&buf, off);
329 		off += clear_word_size;
330 	} while (off < 0);
331 
332 	if (pref_bias_clear_store) {
333 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
334 		uasm_l_clear_nopref(&l, buf);
335 		off = 0;
336 		do {
337 			build_clear_store(&buf, off);
338 			off += clear_word_size;
339 		} while (off < half_clear_loop_size);
340 		pg_addiu(&buf, A0, A0, 2 * off);
341 		off = -off;
342 		do {
343 			if (off == -clear_word_size)
344 				uasm_il_bne(&buf, &r, A0, A2,
345 					    label_clear_nopref);
346 			build_clear_store(&buf, off);
347 			off += clear_word_size;
348 		} while (off < 0);
349 	}
350 
351 	uasm_i_jr(&buf, RA);
352 	uasm_i_nop(&buf);
353 
354 	BUG_ON(buf > &__clear_page_end);
355 
356 	uasm_resolve_relocs(relocs, labels);
357 
358 	pr_debug("Synthesized clear page handler (%u instructions).\n",
359 		 (u32)(buf - &__clear_page_start));
360 
361 	pr_debug("\t.set push\n");
362 	pr_debug("\t.set noreorder\n");
363 	for (i = 0; i < (buf - &__clear_page_start); i++)
364 		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
365 	pr_debug("\t.set pop\n");
366 }
367 
368 static void build_copy_load(u32 **buf, int reg, int off)
369 {
370 	if (cpu_has_64bit_gp_regs) {
371 		uasm_i_ld(buf, reg, off, A1);
372 	} else {
373 		uasm_i_lw(buf, reg, off, A1);
374 	}
375 }
376 
377 static void build_copy_store(u32 **buf, int reg, int off)
378 {
379 	if (cpu_has_64bit_gp_regs) {
380 		uasm_i_sd(buf, reg, off, A0);
381 	} else {
382 		uasm_i_sw(buf, reg, off, A0);
383 	}
384 }
385 
386 static inline void build_copy_load_pref(u32 **buf, int off)
387 {
388 	if (off & cache_line_mask())
389 		return;
390 
391 	if (pref_bias_copy_load)
392 		_uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
393 }
394 
395 static inline void build_copy_store_pref(u32 **buf, int off)
396 {
397 	if (off & cache_line_mask())
398 		return;
399 
400 	if (pref_bias_copy_store) {
401 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
402 			    A0);
403 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
404 		if (cpu_has_cache_cdex_s) {
405 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
406 		} else if (cpu_has_cache_cdex_p) {
407 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
408 				uasm_i_nop(buf);
409 				uasm_i_nop(buf);
410 				uasm_i_nop(buf);
411 				uasm_i_nop(buf);
412 			}
413 
414 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
415 				uasm_i_lw(buf, ZERO, ZERO, AT);
416 
417 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
418 		}
419 	}
420 }
421 
422 void build_copy_page(void)
423 {
424 	int off;
425 	u32 *buf = &__copy_page_start;
426 	struct uasm_label *l = labels;
427 	struct uasm_reloc *r = relocs;
428 	int i;
429 	static atomic_t run_once = ATOMIC_INIT(0);
430 
431 	if (atomic_xchg(&run_once, 1)) {
432 		return;
433 	}
434 
435 	memset(labels, 0, sizeof(labels));
436 	memset(relocs, 0, sizeof(relocs));
437 
438 	set_prefetch_parameters();
439 
440 	/*
441 	 * This algorithm makes the following assumptions:
442 	 *   - All prefetch biases are multiples of 8 words.
443 	 *   - The prefetch biases are less than one page.
444 	 *   - The store prefetch bias isn't greater than the load
445 	 *     prefetch bias.
446 	 */
447 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
448 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
449 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
450 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
451 
452 	off = PAGE_SIZE - pref_bias_copy_load;
453 	if (off > 0xffff || !pref_bias_copy_load)
454 		pg_addiu(&buf, A2, A0, off);
455 	else
456 		uasm_i_ori(&buf, A2, A0, off);
457 
458 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
459 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
460 
461 	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
462 				cache_line_size : 0;
463 	while (off) {
464 		build_copy_load_pref(&buf, -off);
465 		off -= cache_line_size;
466 	}
467 	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
468 				cache_line_size : 0;
469 	while (off) {
470 		build_copy_store_pref(&buf, -off);
471 		off -= cache_line_size;
472 	}
473 	uasm_l_copy_pref_both(&l, buf);
474 	do {
475 		build_copy_load_pref(&buf, off);
476 		build_copy_load(&buf, T0, off);
477 		build_copy_load_pref(&buf, off + copy_word_size);
478 		build_copy_load(&buf, T1, off + copy_word_size);
479 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
480 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
481 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
482 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
483 		build_copy_store_pref(&buf, off);
484 		build_copy_store(&buf, T0, off);
485 		build_copy_store_pref(&buf, off + copy_word_size);
486 		build_copy_store(&buf, T1, off + copy_word_size);
487 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
488 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
489 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
490 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
491 		off += 4 * copy_word_size;
492 	} while (off < half_copy_loop_size);
493 	pg_addiu(&buf, A1, A1, 2 * off);
494 	pg_addiu(&buf, A0, A0, 2 * off);
495 	off = -off;
496 	do {
497 		build_copy_load_pref(&buf, off);
498 		build_copy_load(&buf, T0, off);
499 		build_copy_load_pref(&buf, off + copy_word_size);
500 		build_copy_load(&buf, T1, off + copy_word_size);
501 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
502 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
503 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
504 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
505 		build_copy_store_pref(&buf, off);
506 		build_copy_store(&buf, T0, off);
507 		build_copy_store_pref(&buf, off + copy_word_size);
508 		build_copy_store(&buf, T1, off + copy_word_size);
509 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
510 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
511 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
512 		if (off == -(4 * copy_word_size))
513 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
514 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
515 		off += 4 * copy_word_size;
516 	} while (off < 0);
517 
518 	if (pref_bias_copy_load - pref_bias_copy_store) {
519 		pg_addiu(&buf, A2, A0,
520 			 pref_bias_copy_load - pref_bias_copy_store);
521 		uasm_l_copy_pref_store(&l, buf);
522 		off = 0;
523 		do {
524 			build_copy_load(&buf, T0, off);
525 			build_copy_load(&buf, T1, off + copy_word_size);
526 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
527 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
528 			build_copy_store_pref(&buf, off);
529 			build_copy_store(&buf, T0, off);
530 			build_copy_store_pref(&buf, off + copy_word_size);
531 			build_copy_store(&buf, T1, off + copy_word_size);
532 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
533 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
534 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
535 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
536 			off += 4 * copy_word_size;
537 		} while (off < half_copy_loop_size);
538 		pg_addiu(&buf, A1, A1, 2 * off);
539 		pg_addiu(&buf, A0, A0, 2 * off);
540 		off = -off;
541 		do {
542 			build_copy_load(&buf, T0, off);
543 			build_copy_load(&buf, T1, off + copy_word_size);
544 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
545 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
546 			build_copy_store_pref(&buf, off);
547 			build_copy_store(&buf, T0, off);
548 			build_copy_store_pref(&buf, off + copy_word_size);
549 			build_copy_store(&buf, T1, off + copy_word_size);
550 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
551 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
552 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
553 			if (off == -(4 * copy_word_size))
554 				uasm_il_bne(&buf, &r, A2, A0,
555 					    label_copy_pref_store);
556 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
557 			off += 4 * copy_word_size;
558 		} while (off < 0);
559 	}
560 
561 	if (pref_bias_copy_store) {
562 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
563 		uasm_l_copy_nopref(&l, buf);
564 		off = 0;
565 		do {
566 			build_copy_load(&buf, T0, off);
567 			build_copy_load(&buf, T1, off + copy_word_size);
568 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
569 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
570 			build_copy_store(&buf, T0, off);
571 			build_copy_store(&buf, T1, off + copy_word_size);
572 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
573 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
574 			off += 4 * copy_word_size;
575 		} while (off < half_copy_loop_size);
576 		pg_addiu(&buf, A1, A1, 2 * off);
577 		pg_addiu(&buf, A0, A0, 2 * off);
578 		off = -off;
579 		do {
580 			build_copy_load(&buf, T0, off);
581 			build_copy_load(&buf, T1, off + copy_word_size);
582 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
583 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
584 			build_copy_store(&buf, T0, off);
585 			build_copy_store(&buf, T1, off + copy_word_size);
586 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
587 			if (off == -(4 * copy_word_size))
588 				uasm_il_bne(&buf, &r, A2, A0,
589 					    label_copy_nopref);
590 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
591 			off += 4 * copy_word_size;
592 		} while (off < 0);
593 	}
594 
595 	uasm_i_jr(&buf, RA);
596 	uasm_i_nop(&buf);
597 
598 	BUG_ON(buf > &__copy_page_end);
599 
600 	uasm_resolve_relocs(relocs, labels);
601 
602 	pr_debug("Synthesized copy page handler (%u instructions).\n",
603 		 (u32)(buf - &__copy_page_start));
604 
605 	pr_debug("\t.set push\n");
606 	pr_debug("\t.set noreorder\n");
607 	for (i = 0; i < (buf - &__copy_page_start); i++)
608 		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
609 	pr_debug("\t.set pop\n");
610 }
611 
612 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
613 extern void clear_page_cpu(void *page);
614 extern void copy_page_cpu(void *to, void *from);
615 
616 /*
617  * Pad descriptors to cacheline, since each is exclusively owned by a
618  * particular CPU.
619  */
620 struct dmadscr {
621 	u64 dscr_a;
622 	u64 dscr_b;
623 	u64 pad_a;
624 	u64 pad_b;
625 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
626 
627 void sb1_dma_init(void)
628 {
629 	int i;
630 
631 	for (i = 0; i < DM_NUM_CHANNELS; i++) {
632 		const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
633 				     V_DM_DSCR_BASE_RINGSZ(1);
634 		void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
635 
636 		__raw_writeq(base_val, base_reg);
637 		__raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
638 		__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
639 	}
640 }
641 
642 void clear_page(void *page)
643 {
644 	u64 to_phys = CPHYSADDR((unsigned long)page);
645 	unsigned int cpu = smp_processor_id();
646 
647 	/* if the page is not in KSEG0, use old way */
648 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
649 		return clear_page_cpu(page);
650 
651 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
652 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
653 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
654 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
655 
656 	/*
657 	 * Don't really want to do it this way, but there's no
658 	 * reliable way to delay completion detection.
659 	 */
660 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
661 		 & M_DM_DSCR_BASE_INTERRUPT))
662 		;
663 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
664 }
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 
692 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
693