xref: /openbmc/linux/arch/mips/mm/page.c (revision 7dd65feb)
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/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/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/system.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 "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 __cpuinitdata labels[5];
70 static struct uasm_reloc __cpuinitdata 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  * Maximum sizes:
77  *
78  * R4000 128 bytes S-cache:		0x058 bytes
79  * R4600 v1.7:				0x05c bytes
80  * R4600 v2.0:				0x060 bytes
81  * With prefetching, 16 word strides	0x120 bytes
82  */
83 
84 static u32 clear_page_array[0x120 / 4];
85 
86 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
87 void clear_page_cpu(void *page) __attribute__((alias("clear_page_array")));
88 #else
89 void clear_page(void *page) __attribute__((alias("clear_page_array")));
90 #endif
91 
92 EXPORT_SYMBOL(clear_page);
93 
94 /*
95  * Maximum sizes:
96  *
97  * R4000 128 bytes S-cache:		0x11c bytes
98  * R4600 v1.7:				0x080 bytes
99  * R4600 v2.0:				0x07c bytes
100  * With prefetching, 16 word strides	0x540 bytes
101  */
102 static u32 copy_page_array[0x540 / 4];
103 
104 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
105 void
106 copy_page_cpu(void *to, void *from) __attribute__((alias("copy_page_array")));
107 #else
108 void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
109 #endif
110 
111 EXPORT_SYMBOL(copy_page);
112 
113 
114 static int pref_bias_clear_store __cpuinitdata;
115 static int pref_bias_copy_load __cpuinitdata;
116 static int pref_bias_copy_store __cpuinitdata;
117 
118 static u32 pref_src_mode __cpuinitdata;
119 static u32 pref_dst_mode __cpuinitdata;
120 
121 static int clear_word_size __cpuinitdata;
122 static int copy_word_size __cpuinitdata;
123 
124 static int half_clear_loop_size __cpuinitdata;
125 static int half_copy_loop_size __cpuinitdata;
126 
127 static int cache_line_size __cpuinitdata;
128 #define cache_line_mask() (cache_line_size - 1)
129 
130 static inline void __cpuinit
131 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
132 {
133 	if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
134 		if (off > 0x7fff) {
135 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
136 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
137 		} else
138 			uasm_i_addiu(buf, T9, ZERO, off);
139 		uasm_i_daddu(buf, reg1, reg2, T9);
140 	} else {
141 		if (off > 0x7fff) {
142 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
143 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
144 			UASM_i_ADDU(buf, reg1, reg2, T9);
145 		} else
146 			UASM_i_ADDIU(buf, reg1, reg2, off);
147 	}
148 }
149 
150 static void __cpuinit set_prefetch_parameters(void)
151 {
152 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
153 		clear_word_size = 8;
154 	else
155 		clear_word_size = 4;
156 
157 	if (cpu_has_64bit_gp_regs)
158 		copy_word_size = 8;
159 	else
160 		copy_word_size = 4;
161 
162 	/*
163 	 * The pref's used here are using "streaming" hints, which cause the
164 	 * copied data to be kicked out of the cache sooner.  A page copy often
165 	 * ends up copying a lot more data than is commonly used, so this seems
166 	 * to make sense in terms of reducing cache pollution, but I've no real
167 	 * performance data to back this up.
168 	 */
169 	if (cpu_has_prefetch) {
170 		/*
171 		 * XXX: Most prefetch bias values in here are based on
172 		 * guesswork.
173 		 */
174 		cache_line_size = cpu_dcache_line_size();
175 		switch (current_cpu_type()) {
176 		case CPU_R5500:
177 		case CPU_TX49XX:
178 			/* These processors only support the Pref_Load. */
179 			pref_bias_copy_load = 256;
180 			break;
181 
182 		case CPU_RM9000:
183 			/*
184 			 * As a workaround for erratum G105 which make the
185 			 * PrepareForStore hint unusable we fall back to
186 			 * StoreRetained on the RM9000.  Once it is known which
187 			 * versions of the RM9000 we'll be able to condition-
188 			 * alize this.
189 			 */
190 
191 		case CPU_R10000:
192 		case CPU_R12000:
193 		case CPU_R14000:
194 			/*
195 			 * Those values have been experimentally tuned for an
196 			 * Origin 200.
197 			 */
198 			pref_bias_clear_store = 512;
199 			pref_bias_copy_load = 256;
200 			pref_bias_copy_store = 256;
201 			pref_src_mode = Pref_LoadStreamed;
202 			pref_dst_mode = Pref_StoreStreamed;
203 			break;
204 
205 		case CPU_SB1:
206 		case CPU_SB1A:
207 			pref_bias_clear_store = 128;
208 			pref_bias_copy_load = 128;
209 			pref_bias_copy_store = 128;
210 			/*
211 			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
212 			 * hints are broken.
213 			 */
214 			if (current_cpu_type() == CPU_SB1 &&
215 			    (current_cpu_data.processor_id & 0xff) < 0x02) {
216 				pref_src_mode = Pref_Load;
217 				pref_dst_mode = Pref_Store;
218 			} else {
219 				pref_src_mode = Pref_LoadStreamed;
220 				pref_dst_mode = Pref_StoreStreamed;
221 			}
222 			break;
223 
224 		default:
225 			pref_bias_clear_store = 128;
226 			pref_bias_copy_load = 256;
227 			pref_bias_copy_store = 128;
228 			pref_src_mode = Pref_LoadStreamed;
229 			pref_dst_mode = Pref_PrepareForStore;
230 			break;
231 		}
232 	} else {
233 		if (cpu_has_cache_cdex_s)
234 			cache_line_size = cpu_scache_line_size();
235 		else if (cpu_has_cache_cdex_p)
236 			cache_line_size = cpu_dcache_line_size();
237 	}
238 	/*
239 	 * Too much unrolling will overflow the available space in
240 	 * clear_space_array / copy_page_array.
241 	 */
242 	half_clear_loop_size = min(16 * clear_word_size,
243 				   max(cache_line_size >> 1,
244 				       4 * clear_word_size));
245 	half_copy_loop_size = min(16 * copy_word_size,
246 				  max(cache_line_size >> 1,
247 				      4 * copy_word_size));
248 }
249 
250 static void __cpuinit build_clear_store(u32 **buf, int off)
251 {
252 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
253 		uasm_i_sd(buf, ZERO, off, A0);
254 	} else {
255 		uasm_i_sw(buf, ZERO, off, A0);
256 	}
257 }
258 
259 static inline void __cpuinit build_clear_pref(u32 **buf, int off)
260 {
261 	if (off & cache_line_mask())
262 		return;
263 
264 	if (pref_bias_clear_store) {
265 		uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
266 			    A0);
267 	} else if (cache_line_size == (half_clear_loop_size << 1)) {
268 		if (cpu_has_cache_cdex_s) {
269 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
270 		} else if (cpu_has_cache_cdex_p) {
271 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
272 				uasm_i_nop(buf);
273 				uasm_i_nop(buf);
274 				uasm_i_nop(buf);
275 				uasm_i_nop(buf);
276 			}
277 
278 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
279 				uasm_i_lw(buf, ZERO, ZERO, AT);
280 
281 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
282 		}
283 		}
284 }
285 
286 void __cpuinit build_clear_page(void)
287 {
288 	int off;
289 	u32 *buf = (u32 *)&clear_page_array;
290 	struct uasm_label *l = labels;
291 	struct uasm_reloc *r = relocs;
292 	int i;
293 
294 	memset(labels, 0, sizeof(labels));
295 	memset(relocs, 0, sizeof(relocs));
296 
297 	set_prefetch_parameters();
298 
299 	/*
300 	 * This algorithm makes the following assumptions:
301 	 *   - The prefetch bias is a multiple of 2 words.
302 	 *   - The prefetch bias is less than one page.
303 	 */
304 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
305 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
306 
307 	off = PAGE_SIZE - pref_bias_clear_store;
308 	if (off > 0xffff || !pref_bias_clear_store)
309 		pg_addiu(&buf, A2, A0, off);
310 	else
311 		uasm_i_ori(&buf, A2, A0, off);
312 
313 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
314 		uasm_i_lui(&buf, AT, 0xa000);
315 
316 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
317 	                        * cache_line_size : 0;
318 	while (off) {
319 		build_clear_pref(&buf, -off);
320 		off -= cache_line_size;
321 	}
322 	uasm_l_clear_pref(&l, buf);
323 	do {
324 		build_clear_pref(&buf, off);
325 		build_clear_store(&buf, off);
326 		off += clear_word_size;
327 	} while (off < half_clear_loop_size);
328 	pg_addiu(&buf, A0, A0, 2 * off);
329 	off = -off;
330 	do {
331 		build_clear_pref(&buf, off);
332 		if (off == -clear_word_size)
333 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
334 		build_clear_store(&buf, off);
335 		off += clear_word_size;
336 	} while (off < 0);
337 
338 	if (pref_bias_clear_store) {
339 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
340 		uasm_l_clear_nopref(&l, buf);
341 		off = 0;
342 		do {
343 			build_clear_store(&buf, off);
344 			off += clear_word_size;
345 		} while (off < half_clear_loop_size);
346 		pg_addiu(&buf, A0, A0, 2 * off);
347 		off = -off;
348 		do {
349 			if (off == -clear_word_size)
350 				uasm_il_bne(&buf, &r, A0, A2,
351 					    label_clear_nopref);
352 			build_clear_store(&buf, off);
353 			off += clear_word_size;
354 		} while (off < 0);
355 	}
356 
357 	uasm_i_jr(&buf, RA);
358 	uasm_i_nop(&buf);
359 
360 	BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
361 
362 	uasm_resolve_relocs(relocs, labels);
363 
364 	pr_debug("Synthesized clear page handler (%u instructions).\n",
365 		 (u32)(buf - clear_page_array));
366 
367 	pr_debug("\t.set push\n");
368 	pr_debug("\t.set noreorder\n");
369 	for (i = 0; i < (buf - clear_page_array); i++)
370 		pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
371 	pr_debug("\t.set pop\n");
372 }
373 
374 static void __cpuinit build_copy_load(u32 **buf, int reg, int off)
375 {
376 	if (cpu_has_64bit_gp_regs) {
377 		uasm_i_ld(buf, reg, off, A1);
378 	} else {
379 		uasm_i_lw(buf, reg, off, A1);
380 	}
381 }
382 
383 static void __cpuinit build_copy_store(u32 **buf, int reg, int off)
384 {
385 	if (cpu_has_64bit_gp_regs) {
386 		uasm_i_sd(buf, reg, off, A0);
387 	} else {
388 		uasm_i_sw(buf, reg, off, A0);
389 	}
390 }
391 
392 static inline void build_copy_load_pref(u32 **buf, int off)
393 {
394 	if (off & cache_line_mask())
395 		return;
396 
397 	if (pref_bias_copy_load)
398 		uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
399 }
400 
401 static inline void build_copy_store_pref(u32 **buf, int off)
402 {
403 	if (off & cache_line_mask())
404 		return;
405 
406 	if (pref_bias_copy_store) {
407 		uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
408 			    A0);
409 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
410 		if (cpu_has_cache_cdex_s) {
411 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
412 		} else if (cpu_has_cache_cdex_p) {
413 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
414 				uasm_i_nop(buf);
415 				uasm_i_nop(buf);
416 				uasm_i_nop(buf);
417 				uasm_i_nop(buf);
418 			}
419 
420 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
421 				uasm_i_lw(buf, ZERO, ZERO, AT);
422 
423 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
424 		}
425 	}
426 }
427 
428 void __cpuinit build_copy_page(void)
429 {
430 	int off;
431 	u32 *buf = (u32 *)&copy_page_array;
432 	struct uasm_label *l = labels;
433 	struct uasm_reloc *r = relocs;
434 	int i;
435 
436 	memset(labels, 0, sizeof(labels));
437 	memset(relocs, 0, sizeof(relocs));
438 
439 	set_prefetch_parameters();
440 
441 	/*
442 	 * This algorithm makes the following assumptions:
443 	 *   - All prefetch biases are multiples of 8 words.
444 	 *   - The prefetch biases are less than one page.
445 	 *   - The store prefetch bias isn't greater than the load
446 	 *     prefetch bias.
447 	 */
448 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
449 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
450 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
451 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
452 
453 	off = PAGE_SIZE - pref_bias_copy_load;
454 	if (off > 0xffff || !pref_bias_copy_load)
455 		pg_addiu(&buf, A2, A0, off);
456 	else
457 		uasm_i_ori(&buf, A2, A0, off);
458 
459 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
460 		uasm_i_lui(&buf, AT, 0xa000);
461 
462 	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
463 	                        cache_line_size : 0;
464 	while (off) {
465 		build_copy_load_pref(&buf, -off);
466 		off -= cache_line_size;
467 	}
468 	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
469 	                        cache_line_size : 0;
470 	while (off) {
471 		build_copy_store_pref(&buf, -off);
472 		off -= cache_line_size;
473 	}
474 	uasm_l_copy_pref_both(&l, buf);
475 	do {
476 		build_copy_load_pref(&buf, off);
477 		build_copy_load(&buf, T0, off);
478 		build_copy_load_pref(&buf, off + copy_word_size);
479 		build_copy_load(&buf, T1, off + copy_word_size);
480 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
481 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
482 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
483 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
484 		build_copy_store_pref(&buf, off);
485 		build_copy_store(&buf, T0, off);
486 		build_copy_store_pref(&buf, off + copy_word_size);
487 		build_copy_store(&buf, T1, off + copy_word_size);
488 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
489 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
490 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
491 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
492 		off += 4 * copy_word_size;
493 	} while (off < half_copy_loop_size);
494 	pg_addiu(&buf, A1, A1, 2 * off);
495 	pg_addiu(&buf, A0, A0, 2 * off);
496 	off = -off;
497 	do {
498 		build_copy_load_pref(&buf, off);
499 		build_copy_load(&buf, T0, off);
500 		build_copy_load_pref(&buf, off + copy_word_size);
501 		build_copy_load(&buf, T1, off + copy_word_size);
502 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
503 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
504 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
505 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
506 		build_copy_store_pref(&buf, off);
507 		build_copy_store(&buf, T0, off);
508 		build_copy_store_pref(&buf, off + copy_word_size);
509 		build_copy_store(&buf, T1, off + copy_word_size);
510 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
511 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
512 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
513 		if (off == -(4 * copy_word_size))
514 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
515 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
516 		off += 4 * copy_word_size;
517 	} while (off < 0);
518 
519 	if (pref_bias_copy_load - pref_bias_copy_store) {
520 		pg_addiu(&buf, A2, A0,
521 			 pref_bias_copy_load - pref_bias_copy_store);
522 		uasm_l_copy_pref_store(&l, buf);
523 		off = 0;
524 		do {
525 			build_copy_load(&buf, T0, off);
526 			build_copy_load(&buf, T1, off + copy_word_size);
527 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
528 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
529 			build_copy_store_pref(&buf, off);
530 			build_copy_store(&buf, T0, off);
531 			build_copy_store_pref(&buf, off + copy_word_size);
532 			build_copy_store(&buf, T1, off + copy_word_size);
533 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
534 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
535 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
536 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
537 			off += 4 * copy_word_size;
538 		} while (off < half_copy_loop_size);
539 		pg_addiu(&buf, A1, A1, 2 * off);
540 		pg_addiu(&buf, A0, A0, 2 * off);
541 		off = -off;
542 		do {
543 			build_copy_load(&buf, T0, off);
544 			build_copy_load(&buf, T1, off + copy_word_size);
545 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
546 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
547 			build_copy_store_pref(&buf, off);
548 			build_copy_store(&buf, T0, off);
549 			build_copy_store_pref(&buf, off + copy_word_size);
550 			build_copy_store(&buf, T1, off + copy_word_size);
551 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
552 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
553 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
554 			if (off == -(4 * copy_word_size))
555 				uasm_il_bne(&buf, &r, A2, A0,
556 					    label_copy_pref_store);
557 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
558 			off += 4 * copy_word_size;
559 		} while (off < 0);
560 	}
561 
562 	if (pref_bias_copy_store) {
563 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
564 		uasm_l_copy_nopref(&l, buf);
565 		off = 0;
566 		do {
567 			build_copy_load(&buf, T0, off);
568 			build_copy_load(&buf, T1, off + copy_word_size);
569 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
570 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
571 			build_copy_store(&buf, T0, off);
572 			build_copy_store(&buf, T1, off + copy_word_size);
573 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
574 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
575 			off += 4 * copy_word_size;
576 		} while (off < half_copy_loop_size);
577 		pg_addiu(&buf, A1, A1, 2 * off);
578 		pg_addiu(&buf, A0, A0, 2 * off);
579 		off = -off;
580 		do {
581 			build_copy_load(&buf, T0, off);
582 			build_copy_load(&buf, T1, off + copy_word_size);
583 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
584 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
585 			build_copy_store(&buf, T0, off);
586 			build_copy_store(&buf, T1, off + copy_word_size);
587 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
588 			if (off == -(4 * copy_word_size))
589 				uasm_il_bne(&buf, &r, A2, A0,
590 					    label_copy_nopref);
591 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
592 			off += 4 * copy_word_size;
593 		} while (off < 0);
594 	}
595 
596 	uasm_i_jr(&buf, RA);
597 	uasm_i_nop(&buf);
598 
599 	BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array));
600 
601 	uasm_resolve_relocs(relocs, labels);
602 
603 	pr_debug("Synthesized copy page handler (%u instructions).\n",
604 		 (u32)(buf - copy_page_array));
605 
606 	pr_debug("\t.set push\n");
607 	pr_debug("\t.set noreorder\n");
608 	for (i = 0; i < (buf - copy_page_array); i++)
609 		pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
610 	pr_debug("\t.set pop\n");
611 }
612 
613 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
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 
665 void copy_page(void *to, void *from)
666 {
667 	u64 from_phys = CPHYSADDR((unsigned long)from);
668 	u64 to_phys = CPHYSADDR((unsigned long)to);
669 	unsigned int cpu = smp_processor_id();
670 
671 	/* if any page is not in KSEG0, use old way */
672 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
673 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
674 		return copy_page_cpu(to, from);
675 
676 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
677 				 M_DM_DSCRA_INTERRUPT;
678 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
679 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
680 
681 	/*
682 	 * Don't really want to do it this way, but there's no
683 	 * reliable way to delay completion detection.
684 	 */
685 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
686 		 & M_DM_DSCR_BASE_INTERRUPT))
687 		;
688 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
689 }
690 
691 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
692