xref: /openbmc/linux/arch/mips/mm/page.c (revision 9ac8d3fb)
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  */
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/mm.h>
14 #include <linux/module.h>
15 #include <linux/proc_fs.h>
16 
17 #include <asm/bugs.h>
18 #include <asm/cacheops.h>
19 #include <asm/inst.h>
20 #include <asm/io.h>
21 #include <asm/page.h>
22 #include <asm/pgtable.h>
23 #include <asm/prefetch.h>
24 #include <asm/system.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 "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 __cpuinitdata labels[5];
69 static struct uasm_reloc __cpuinitdata 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  * Maximum sizes:
76  *
77  * R4000 128 bytes S-cache:		0x058 bytes
78  * R4600 v1.7:				0x05c bytes
79  * R4600 v2.0:				0x060 bytes
80  * With prefetching, 16 word strides	0x120 bytes
81  */
82 
83 static u32 clear_page_array[0x120 / 4];
84 
85 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
86 void clear_page_cpu(void *page) __attribute__((alias("clear_page_array")));
87 #else
88 void clear_page(void *page) __attribute__((alias("clear_page_array")));
89 #endif
90 
91 EXPORT_SYMBOL(clear_page);
92 
93 /*
94  * Maximum sizes:
95  *
96  * R4000 128 bytes S-cache:		0x11c bytes
97  * R4600 v1.7:				0x080 bytes
98  * R4600 v2.0:				0x07c bytes
99  * With prefetching, 16 word strides	0x540 bytes
100  */
101 static u32 copy_page_array[0x540 / 4];
102 
103 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
104 void
105 copy_page_cpu(void *to, void *from) __attribute__((alias("copy_page_array")));
106 #else
107 void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
108 #endif
109 
110 EXPORT_SYMBOL(copy_page);
111 
112 
113 static int pref_bias_clear_store __cpuinitdata;
114 static int pref_bias_copy_load __cpuinitdata;
115 static int pref_bias_copy_store __cpuinitdata;
116 
117 static u32 pref_src_mode __cpuinitdata;
118 static u32 pref_dst_mode __cpuinitdata;
119 
120 static int clear_word_size __cpuinitdata;
121 static int copy_word_size __cpuinitdata;
122 
123 static int half_clear_loop_size __cpuinitdata;
124 static int half_copy_loop_size __cpuinitdata;
125 
126 static int cache_line_size __cpuinitdata;
127 #define cache_line_mask() (cache_line_size - 1)
128 
129 static inline void __cpuinit
130 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
131 {
132 	if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
133 		if (off > 0x7fff) {
134 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
135 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
136 		} else
137 			uasm_i_addiu(buf, T9, ZERO, off);
138 		uasm_i_daddu(buf, reg1, reg2, T9);
139 	} else {
140 		if (off > 0x7fff) {
141 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
142 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
143 			UASM_i_ADDU(buf, reg1, reg2, T9);
144 		} else
145 			UASM_i_ADDIU(buf, reg1, reg2, off);
146 	}
147 }
148 
149 static void __cpuinit set_prefetch_parameters(void)
150 {
151 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
152 		clear_word_size = 8;
153 	else
154 		clear_word_size = 4;
155 
156 	if (cpu_has_64bit_gp_regs)
157 		copy_word_size = 8;
158 	else
159 		copy_word_size = 4;
160 
161 	/*
162 	 * The pref's used here are using "streaming" hints, which cause the
163 	 * copied data to be kicked out of the cache sooner.  A page copy often
164 	 * ends up copying a lot more data than is commonly used, so this seems
165 	 * to make sense in terms of reducing cache pollution, but I've no real
166 	 * performance data to back this up.
167 	 */
168 	if (cpu_has_prefetch) {
169 		/*
170 		 * XXX: Most prefetch bias values in here are based on
171 		 * guesswork.
172 		 */
173 		cache_line_size = cpu_dcache_line_size();
174 		switch (current_cpu_type()) {
175 		case CPU_TX49XX:
176 			/* TX49 supports only Pref_Load */
177 			pref_bias_copy_load = 256;
178 			break;
179 
180 		case CPU_RM9000:
181 			/*
182 			 * As a workaround for erratum G105 which make the
183 			 * PrepareForStore hint unusable we fall back to
184 			 * StoreRetained on the RM9000.  Once it is known which
185 			 * versions of the RM9000 we'll be able to condition-
186 			 * alize this.
187 			 */
188 
189 		case CPU_R10000:
190 		case CPU_R12000:
191 		case CPU_R14000:
192 			/*
193 			 * Those values have been experimentally tuned for an
194 			 * Origin 200.
195 			 */
196 			pref_bias_clear_store = 512;
197 			pref_bias_copy_load = 256;
198 			pref_bias_copy_store = 256;
199 			pref_src_mode = Pref_LoadStreamed;
200 			pref_dst_mode = Pref_StoreStreamed;
201 			break;
202 
203 		case CPU_SB1:
204 		case CPU_SB1A:
205 			pref_bias_clear_store = 128;
206 			pref_bias_copy_load = 128;
207 			pref_bias_copy_store = 128;
208 			/*
209 			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
210 			 * hints are broken.
211 			 */
212 			if (current_cpu_type() == CPU_SB1 &&
213 			    (current_cpu_data.processor_id & 0xff) < 0x02) {
214 				pref_src_mode = Pref_Load;
215 				pref_dst_mode = Pref_Store;
216 			} else {
217 				pref_src_mode = Pref_LoadStreamed;
218 				pref_dst_mode = Pref_StoreStreamed;
219 			}
220 			break;
221 
222 		default:
223 			pref_bias_clear_store = 128;
224 			pref_bias_copy_load = 256;
225 			pref_bias_copy_store = 128;
226 			pref_src_mode = Pref_LoadStreamed;
227 			pref_dst_mode = Pref_PrepareForStore;
228 			break;
229 		}
230 	} else {
231 		if (cpu_has_cache_cdex_s)
232 			cache_line_size = cpu_scache_line_size();
233 		else if (cpu_has_cache_cdex_p)
234 			cache_line_size = cpu_dcache_line_size();
235 	}
236 	/*
237 	 * Too much unrolling will overflow the available space in
238 	 * clear_space_array / copy_page_array.
239 	 */
240 	half_clear_loop_size = min(16 * clear_word_size,
241 				   max(cache_line_size >> 1,
242 				       4 * clear_word_size));
243 	half_copy_loop_size = min(16 * copy_word_size,
244 				  max(cache_line_size >> 1,
245 				      4 * copy_word_size));
246 }
247 
248 static void __cpuinit build_clear_store(u32 **buf, int off)
249 {
250 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
251 		uasm_i_sd(buf, ZERO, off, A0);
252 	} else {
253 		uasm_i_sw(buf, ZERO, off, A0);
254 	}
255 }
256 
257 static inline void __cpuinit build_clear_pref(u32 **buf, int off)
258 {
259 	if (off & cache_line_mask())
260 		return;
261 
262 	if (pref_bias_clear_store) {
263 		uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
264 			    A0);
265 	} else if (cache_line_size == (half_clear_loop_size << 1)) {
266 		if (cpu_has_cache_cdex_s) {
267 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
268 		} else if (cpu_has_cache_cdex_p) {
269 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
270 				uasm_i_nop(buf);
271 				uasm_i_nop(buf);
272 				uasm_i_nop(buf);
273 				uasm_i_nop(buf);
274 			}
275 
276 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
277 				uasm_i_lw(buf, ZERO, ZERO, AT);
278 
279 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
280 		}
281 		}
282 }
283 
284 void __cpuinit build_clear_page(void)
285 {
286 	int off;
287 	u32 *buf = (u32 *)&clear_page_array;
288 	struct uasm_label *l = labels;
289 	struct uasm_reloc *r = relocs;
290 	int i;
291 
292 	memset(labels, 0, sizeof(labels));
293 	memset(relocs, 0, sizeof(relocs));
294 
295 	set_prefetch_parameters();
296 
297 	/*
298 	 * This algorithm makes the following assumptions:
299 	 *   - The prefetch bias is a multiple of 2 words.
300 	 *   - The prefetch bias is less than one page.
301 	 */
302 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
303 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
304 
305 	off = PAGE_SIZE - pref_bias_clear_store;
306 	if (off > 0xffff || !pref_bias_clear_store)
307 		pg_addiu(&buf, A2, A0, off);
308 	else
309 		uasm_i_ori(&buf, A2, A0, off);
310 
311 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
312 		uasm_i_lui(&buf, AT, 0xa000);
313 
314 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
315 	                        * cache_line_size : 0;
316 	while (off) {
317 		build_clear_pref(&buf, -off);
318 		off -= cache_line_size;
319 	}
320 	uasm_l_clear_pref(&l, buf);
321 	do {
322 		build_clear_pref(&buf, off);
323 		build_clear_store(&buf, off);
324 		off += clear_word_size;
325 	} while (off < half_clear_loop_size);
326 	pg_addiu(&buf, A0, A0, 2 * off);
327 	off = -off;
328 	do {
329 		build_clear_pref(&buf, off);
330 		if (off == -clear_word_size)
331 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
332 		build_clear_store(&buf, off);
333 		off += clear_word_size;
334 	} while (off < 0);
335 
336 	if (pref_bias_clear_store) {
337 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
338 		uasm_l_clear_nopref(&l, buf);
339 		off = 0;
340 		do {
341 			build_clear_store(&buf, off);
342 			off += clear_word_size;
343 		} while (off < half_clear_loop_size);
344 		pg_addiu(&buf, A0, A0, 2 * off);
345 		off = -off;
346 		do {
347 			if (off == -clear_word_size)
348 				uasm_il_bne(&buf, &r, A0, A2,
349 					    label_clear_nopref);
350 			build_clear_store(&buf, off);
351 			off += clear_word_size;
352 		} while (off < 0);
353 	}
354 
355 	uasm_i_jr(&buf, RA);
356 	uasm_i_nop(&buf);
357 
358 	BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
359 
360 	uasm_resolve_relocs(relocs, labels);
361 
362 	pr_debug("Synthesized clear page handler (%u instructions).\n",
363 		 (u32)(buf - clear_page_array));
364 
365 	pr_debug("\t.set push\n");
366 	pr_debug("\t.set noreorder\n");
367 	for (i = 0; i < (buf - clear_page_array); i++)
368 		pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
369 	pr_debug("\t.set pop\n");
370 }
371 
372 static void __cpuinit build_copy_load(u32 **buf, int reg, int off)
373 {
374 	if (cpu_has_64bit_gp_regs) {
375 		uasm_i_ld(buf, reg, off, A1);
376 	} else {
377 		uasm_i_lw(buf, reg, off, A1);
378 	}
379 }
380 
381 static void __cpuinit build_copy_store(u32 **buf, int reg, int off)
382 {
383 	if (cpu_has_64bit_gp_regs) {
384 		uasm_i_sd(buf, reg, off, A0);
385 	} else {
386 		uasm_i_sw(buf, reg, off, A0);
387 	}
388 }
389 
390 static inline void build_copy_load_pref(u32 **buf, int off)
391 {
392 	if (off & cache_line_mask())
393 		return;
394 
395 	if (pref_bias_copy_load)
396 		uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
397 }
398 
399 static inline void build_copy_store_pref(u32 **buf, int off)
400 {
401 	if (off & cache_line_mask())
402 		return;
403 
404 	if (pref_bias_copy_store) {
405 		uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
406 			    A0);
407 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
408 		if (cpu_has_cache_cdex_s) {
409 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
410 		} else if (cpu_has_cache_cdex_p) {
411 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
412 				uasm_i_nop(buf);
413 				uasm_i_nop(buf);
414 				uasm_i_nop(buf);
415 				uasm_i_nop(buf);
416 			}
417 
418 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
419 				uasm_i_lw(buf, ZERO, ZERO, AT);
420 
421 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
422 		}
423 	}
424 }
425 
426 void __cpuinit build_copy_page(void)
427 {
428 	int off;
429 	u32 *buf = (u32 *)&copy_page_array;
430 	struct uasm_label *l = labels;
431 	struct uasm_reloc *r = relocs;
432 	int i;
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, 0xa000);
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_array + ARRAY_SIZE(copy_page_array));
598 
599 	uasm_resolve_relocs(relocs, labels);
600 
601 	pr_debug("Synthesized copy page handler (%u instructions).\n",
602 		 (u32)(buf - copy_page_array));
603 
604 	pr_debug("\t.set push\n");
605 	pr_debug("\t.set noreorder\n");
606 	for (i = 0; i < (buf - copy_page_array); i++)
607 		pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
608 	pr_debug("\t.set pop\n");
609 }
610 
611 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
612 
613 /*
614  * Pad descriptors to cacheline, since each is exclusively owned by a
615  * particular CPU.
616  */
617 struct dmadscr {
618 	u64 dscr_a;
619 	u64 dscr_b;
620 	u64 pad_a;
621 	u64 pad_b;
622 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
623 
624 void sb1_dma_init(void)
625 {
626 	int i;
627 
628 	for (i = 0; i < DM_NUM_CHANNELS; i++) {
629 		const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
630 				     V_DM_DSCR_BASE_RINGSZ(1);
631 		void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
632 
633 		__raw_writeq(base_val, base_reg);
634 		__raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
635 		__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
636 	}
637 }
638 
639 void clear_page(void *page)
640 {
641 	u64 to_phys = CPHYSADDR((unsigned long)page);
642 	unsigned int cpu = smp_processor_id();
643 
644 	/* if the page is not in KSEG0, use old way */
645 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
646 		return clear_page_cpu(page);
647 
648 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
649 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
650 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
651 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
652 
653 	/*
654 	 * Don't really want to do it this way, but there's no
655 	 * reliable way to delay completion detection.
656 	 */
657 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
658 		 & M_DM_DSCR_BASE_INTERRUPT))
659 		;
660 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
661 }
662 
663 void copy_page(void *to, void *from)
664 {
665 	u64 from_phys = CPHYSADDR((unsigned long)from);
666 	u64 to_phys = CPHYSADDR((unsigned long)to);
667 	unsigned int cpu = smp_processor_id();
668 
669 	/* if any page is not in KSEG0, use old way */
670 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
671 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
672 		return copy_page_cpu(to, from);
673 
674 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
675 				 M_DM_DSCRA_INTERRUPT;
676 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
677 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
678 
679 	/*
680 	 * Don't really want to do it this way, but there's no
681 	 * reliable way to delay completion detection.
682 	 */
683 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
684 		 & M_DM_DSCR_BASE_INTERRUPT))
685 		;
686 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
687 }
688 
689 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
690