xref: /openbmc/linux/arch/mips/mm/page.c (revision 22246614)
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. 8 words sounds generous,
239 	 * but a R4000 with 128 byte L2 line length can exceed even that.
240 	 */
241 	half_clear_loop_size = min(8 * clear_word_size,
242 				   max(cache_line_size >> 1,
243 				       4 * clear_word_size));
244 	half_copy_loop_size = min(8 * copy_word_size,
245 				  max(cache_line_size >> 1,
246 				      4 * copy_word_size));
247 }
248 
249 static void __cpuinit build_clear_store(u32 **buf, int off)
250 {
251 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
252 		uasm_i_sd(buf, ZERO, off, A0);
253 	} else {
254 		uasm_i_sw(buf, ZERO, off, A0);
255 	}
256 }
257 
258 static inline void __cpuinit build_clear_pref(u32 **buf, int off)
259 {
260 	if (off & cache_line_mask())
261 		return;
262 
263 	if (pref_bias_clear_store) {
264 		uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
265 			    A0);
266 	} else 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 void __cpuinit build_clear_page(void)
284 {
285 	int off;
286 	u32 *buf = (u32 *)&clear_page_array;
287 	struct uasm_label *l = labels;
288 	struct uasm_reloc *r = relocs;
289 	int i;
290 
291 	memset(labels, 0, sizeof(labels));
292 	memset(relocs, 0, sizeof(relocs));
293 
294 	set_prefetch_parameters();
295 
296 	/*
297 	 * This algorithm makes the following assumptions:
298 	 *   - The prefetch bias is a multiple of 2 words.
299 	 *   - The prefetch bias is less than one page.
300 	 */
301 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
302 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
303 
304 	off = PAGE_SIZE - pref_bias_clear_store;
305 	if (off > 0xffff || !pref_bias_clear_store)
306 		pg_addiu(&buf, A2, A0, off);
307 	else
308 		uasm_i_ori(&buf, A2, A0, off);
309 
310 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
311 		uasm_i_lui(&buf, AT, 0xa000);
312 
313 	off = min(8, pref_bias_clear_store / cache_line_size) *
314 	      cache_line_size;
315 	while (off) {
316 		build_clear_pref(&buf, -off);
317 		off -= cache_line_size;
318 	}
319 	uasm_l_clear_pref(&l, buf);
320 	do {
321 		build_clear_pref(&buf, off);
322 		build_clear_store(&buf, off);
323 		off += clear_word_size;
324 	} while (off < half_clear_loop_size);
325 	pg_addiu(&buf, A0, A0, 2 * off);
326 	off = -off;
327 	do {
328 		build_clear_pref(&buf, off);
329 		if (off == -clear_word_size)
330 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
331 		build_clear_store(&buf, off);
332 		off += clear_word_size;
333 	} while (off < 0);
334 
335 	if (pref_bias_clear_store) {
336 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
337 		uasm_l_clear_nopref(&l, buf);
338 		off = 0;
339 		do {
340 			build_clear_store(&buf, off);
341 			off += clear_word_size;
342 		} while (off < half_clear_loop_size);
343 		pg_addiu(&buf, A0, A0, 2 * off);
344 		off = -off;
345 		do {
346 			if (off == -clear_word_size)
347 				uasm_il_bne(&buf, &r, A0, A2,
348 					    label_clear_nopref);
349 			build_clear_store(&buf, off);
350 			off += clear_word_size;
351 		} while (off < 0);
352 	}
353 
354 	uasm_i_jr(&buf, RA);
355 	uasm_i_nop(&buf);
356 
357 	BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
358 
359 	uasm_resolve_relocs(relocs, labels);
360 
361 	pr_debug("Synthesized clear page handler (%u instructions).\n",
362 		 (u32)(buf - clear_page_array));
363 
364 	pr_debug("\t.set push\n");
365 	pr_debug("\t.set noreorder\n");
366 	for (i = 0; i < (buf - clear_page_array); i++)
367 		pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
368 	pr_debug("\t.set pop\n");
369 }
370 
371 static void __cpuinit build_copy_load(u32 **buf, int reg, int off)
372 {
373 	if (cpu_has_64bit_gp_regs) {
374 		uasm_i_ld(buf, reg, off, A1);
375 	} else {
376 		uasm_i_lw(buf, reg, off, A1);
377 	}
378 }
379 
380 static void __cpuinit build_copy_store(u32 **buf, int reg, int off)
381 {
382 	if (cpu_has_64bit_gp_regs) {
383 		uasm_i_sd(buf, reg, off, A0);
384 	} else {
385 		uasm_i_sw(buf, reg, off, A0);
386 	}
387 }
388 
389 static inline void build_copy_load_pref(u32 **buf, int off)
390 {
391 	if (off & cache_line_mask())
392 		return;
393 
394 	if (pref_bias_copy_load)
395 		uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
396 }
397 
398 static inline void build_copy_store_pref(u32 **buf, int off)
399 {
400 	if (off & cache_line_mask())
401 		return;
402 
403 	if (pref_bias_copy_store) {
404 		uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
405 			    A0);
406 	} else if (cpu_has_cache_cdex_s) {
407 		uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
408 	} else if (cpu_has_cache_cdex_p) {
409 		if (R4600_V1_HIT_CACHEOP_WAR && 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 (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
417 			uasm_i_lw(buf, ZERO, ZERO, AT);
418 
419 		uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
420 	}
421 }
422 
423 void __cpuinit build_copy_page(void)
424 {
425 	int off;
426 	u32 *buf = (u32 *)&copy_page_array;
427 	struct uasm_label *l = labels;
428 	struct uasm_reloc *r = relocs;
429 	int i;
430 
431 	memset(labels, 0, sizeof(labels));
432 	memset(relocs, 0, sizeof(relocs));
433 
434 	set_prefetch_parameters();
435 
436 	/*
437 	 * This algorithm makes the following assumptions:
438 	 *   - All prefetch biases are multiples of 8 words.
439 	 *   - The prefetch biases are less than one page.
440 	 *   - The store prefetch bias isn't greater than the load
441 	 *     prefetch bias.
442 	 */
443 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
444 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
445 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
446 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
447 
448 	off = PAGE_SIZE - pref_bias_copy_load;
449 	if (off > 0xffff || !pref_bias_copy_load)
450 		pg_addiu(&buf, A2, A0, off);
451 	else
452 		uasm_i_ori(&buf, A2, A0, off);
453 
454 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
455 		uasm_i_lui(&buf, AT, 0xa000);
456 
457 	off = min(8, pref_bias_copy_load / cache_line_size) * cache_line_size;
458 	while (off) {
459 		build_copy_load_pref(&buf, -off);
460 		off -= cache_line_size;
461 	}
462 	off = min(8, pref_bias_copy_store / cache_line_size) * cache_line_size;
463 	while (off) {
464 		build_copy_store_pref(&buf, -off);
465 		off -= cache_line_size;
466 	}
467 	uasm_l_copy_pref_both(&l, buf);
468 	do {
469 		build_copy_load_pref(&buf, off);
470 		build_copy_load(&buf, T0, off);
471 		build_copy_load_pref(&buf, off + copy_word_size);
472 		build_copy_load(&buf, T1, off + copy_word_size);
473 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
474 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
475 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
476 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
477 		build_copy_store_pref(&buf, off);
478 		build_copy_store(&buf, T0, off);
479 		build_copy_store_pref(&buf, off + copy_word_size);
480 		build_copy_store(&buf, T1, off + copy_word_size);
481 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
482 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
483 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
484 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
485 		off += 4 * copy_word_size;
486 	} while (off < half_copy_loop_size);
487 	pg_addiu(&buf, A1, A1, 2 * off);
488 	pg_addiu(&buf, A0, A0, 2 * off);
489 	off = -off;
490 	do {
491 		build_copy_load_pref(&buf, off);
492 		build_copy_load(&buf, T0, off);
493 		build_copy_load_pref(&buf, off + copy_word_size);
494 		build_copy_load(&buf, T1, off + copy_word_size);
495 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
496 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
497 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
498 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
499 		build_copy_store_pref(&buf, off);
500 		build_copy_store(&buf, T0, off);
501 		build_copy_store_pref(&buf, off + copy_word_size);
502 		build_copy_store(&buf, T1, off + copy_word_size);
503 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
504 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
505 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
506 		if (off == -(4 * copy_word_size))
507 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
508 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
509 		off += 4 * copy_word_size;
510 	} while (off < 0);
511 
512 	if (pref_bias_copy_load - pref_bias_copy_store) {
513 		pg_addiu(&buf, A2, A0,
514 			 pref_bias_copy_load - pref_bias_copy_store);
515 		uasm_l_copy_pref_store(&l, buf);
516 		off = 0;
517 		do {
518 			build_copy_load(&buf, T0, off);
519 			build_copy_load(&buf, T1, off + copy_word_size);
520 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
521 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
522 			build_copy_store_pref(&buf, off);
523 			build_copy_store(&buf, T0, off);
524 			build_copy_store_pref(&buf, off + copy_word_size);
525 			build_copy_store(&buf, T1, off + copy_word_size);
526 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
527 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
528 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
529 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
530 			off += 4 * copy_word_size;
531 		} while (off < half_copy_loop_size);
532 		pg_addiu(&buf, A1, A1, 2 * off);
533 		pg_addiu(&buf, A0, A0, 2 * off);
534 		off = -off;
535 		do {
536 			build_copy_load(&buf, T0, off);
537 			build_copy_load(&buf, T1, off + copy_word_size);
538 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
539 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
540 			build_copy_store_pref(&buf, off);
541 			build_copy_store(&buf, T0, off);
542 			build_copy_store_pref(&buf, off + copy_word_size);
543 			build_copy_store(&buf, T1, off + copy_word_size);
544 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
545 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
546 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
547 			if (off == -(4 * copy_word_size))
548 				uasm_il_bne(&buf, &r, A2, A0,
549 					    label_copy_pref_store);
550 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
551 			off += 4 * copy_word_size;
552 		} while (off < 0);
553 	}
554 
555 	if (pref_bias_copy_store) {
556 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
557 		uasm_l_copy_nopref(&l, buf);
558 		off = 0;
559 		do {
560 			build_copy_load(&buf, T0, off);
561 			build_copy_load(&buf, T1, off + copy_word_size);
562 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
563 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
564 			build_copy_store(&buf, T0, off);
565 			build_copy_store(&buf, T1, off + copy_word_size);
566 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
567 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
568 			off += 4 * copy_word_size;
569 		} while (off < half_copy_loop_size);
570 		pg_addiu(&buf, A1, A1, 2 * off);
571 		pg_addiu(&buf, A0, A0, 2 * off);
572 		off = -off;
573 		do {
574 			build_copy_load(&buf, T0, off);
575 			build_copy_load(&buf, T1, off + copy_word_size);
576 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
577 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
578 			build_copy_store(&buf, T0, off);
579 			build_copy_store(&buf, T1, off + copy_word_size);
580 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
581 			if (off == -(4 * copy_word_size))
582 				uasm_il_bne(&buf, &r, A2, A0,
583 					    label_copy_nopref);
584 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
585 			off += 4 * copy_word_size;
586 		} while (off < 0);
587 	}
588 
589 	uasm_i_jr(&buf, RA);
590 	uasm_i_nop(&buf);
591 
592 	BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array));
593 
594 	uasm_resolve_relocs(relocs, labels);
595 
596 	pr_debug("Synthesized copy page handler (%u instructions).\n",
597 		 (u32)(buf - copy_page_array));
598 
599 	pr_debug("\t.set push\n");
600 	pr_debug("\t.set noreorder\n");
601 	for (i = 0; i < (buf - copy_page_array); i++)
602 		pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
603 	pr_debug("\t.set pop\n");
604 }
605 
606 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
607 
608 /*
609  * Pad descriptors to cacheline, since each is exclusively owned by a
610  * particular CPU.
611  */
612 struct dmadscr {
613 	u64 dscr_a;
614 	u64 dscr_b;
615 	u64 pad_a;
616 	u64 pad_b;
617 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
618 
619 void sb1_dma_init(void)
620 {
621 	int i;
622 
623 	for (i = 0; i < DM_NUM_CHANNELS; i++) {
624 		const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
625 				     V_DM_DSCR_BASE_RINGSZ(1);
626 		void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
627 
628 		__raw_writeq(base_val, base_reg);
629 		__raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
630 		__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
631 	}
632 }
633 
634 void clear_page(void *page)
635 {
636 	u64 to_phys = CPHYSADDR((unsigned long)page);
637 	unsigned int cpu = smp_processor_id();
638 
639 	/* if the page is not in KSEG0, use old way */
640 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
641 		return clear_page_cpu(page);
642 
643 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
644 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
645 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
646 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
647 
648 	/*
649 	 * Don't really want to do it this way, but there's no
650 	 * reliable way to delay completion detection.
651 	 */
652 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
653 		 & M_DM_DSCR_BASE_INTERRUPT))
654 		;
655 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
656 }
657 
658 void copy_page(void *to, void *from)
659 {
660 	u64 from_phys = CPHYSADDR((unsigned long)from);
661 	u64 to_phys = CPHYSADDR((unsigned long)to);
662 	unsigned int cpu = smp_processor_id();
663 
664 	/* if any page is not in KSEG0, use old way */
665 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
666 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
667 		return copy_page_cpu(to, from);
668 
669 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
670 				 M_DM_DSCRA_INTERRUPT;
671 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
672 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
673 
674 	/*
675 	 * Don't really want to do it this way, but there's no
676 	 * reliable way to delay completion detection.
677 	 */
678 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
679 		 & M_DM_DSCR_BASE_INTERRUPT))
680 		;
681 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
682 }
683 
684 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
685