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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
pg_addiu(u32 ** buf,unsigned int reg1,unsigned int reg2,unsigned int off)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 
set_prefetch_parameters(void)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 		default:
192 			pref_bias_clear_store = 128;
193 			pref_bias_copy_load = 256;
194 			pref_bias_copy_store = 128;
195 			pref_src_mode = Pref_LoadStreamed;
196 			if (cpu_has_mips_r6)
197 				/*
198 				 * Bit 30 (Pref_PrepareForStore) has been
199 				 * removed from MIPS R6. Use bit 5
200 				 * (Pref_StoreStreamed).
201 				 */
202 				pref_dst_mode = Pref_StoreStreamed;
203 			else
204 				pref_dst_mode = Pref_PrepareForStore;
205 			break;
206 		}
207 	} else {
208 		if (cpu_has_cache_cdex_s)
209 			cache_line_size = cpu_scache_line_size();
210 		else if (cpu_has_cache_cdex_p)
211 			cache_line_size = cpu_dcache_line_size();
212 	}
213 	/*
214 	 * Too much unrolling will overflow the available space in
215 	 * clear_space_array / copy_page_array.
216 	 */
217 	half_clear_loop_size = min(16 * clear_word_size,
218 				   max(cache_line_size >> 1,
219 				       4 * clear_word_size));
220 	half_copy_loop_size = min(16 * copy_word_size,
221 				  max(cache_line_size >> 1,
222 				      4 * copy_word_size));
223 }
224 
build_clear_store(u32 ** buf,int off)225 static void build_clear_store(u32 **buf, int off)
226 {
227 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
228 		uasm_i_sd(buf, ZERO, off, A0);
229 	} else {
230 		uasm_i_sw(buf, ZERO, off, A0);
231 	}
232 }
233 
build_clear_pref(u32 ** buf,int off)234 static inline void build_clear_pref(u32 **buf, int off)
235 {
236 	if (off & cache_line_mask())
237 		return;
238 
239 	if (pref_bias_clear_store) {
240 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
241 			    A0);
242 	} else if (cache_line_size == (half_clear_loop_size << 1)) {
243 		if (cpu_has_cache_cdex_s) {
244 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
245 		} else if (cpu_has_cache_cdex_p) {
246 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
247 				uasm_i_nop(buf);
248 				uasm_i_nop(buf);
249 				uasm_i_nop(buf);
250 				uasm_i_nop(buf);
251 			}
252 
253 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
254 				uasm_i_lw(buf, ZERO, ZERO, AT);
255 
256 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
257 		}
258 	}
259 }
260 
261 extern u32 __clear_page_start;
262 extern u32 __clear_page_end;
263 extern u32 __copy_page_start;
264 extern u32 __copy_page_end;
265 
build_clear_page(void)266 void build_clear_page(void)
267 {
268 	int off;
269 	u32 *buf = &__clear_page_start;
270 	struct uasm_label *l = labels;
271 	struct uasm_reloc *r = relocs;
272 	int i;
273 	static atomic_t run_once = ATOMIC_INIT(0);
274 
275 	if (atomic_xchg(&run_once, 1)) {
276 		return;
277 	}
278 
279 	memset(labels, 0, sizeof(labels));
280 	memset(relocs, 0, sizeof(relocs));
281 
282 	set_prefetch_parameters();
283 
284 	/*
285 	 * This algorithm makes the following assumptions:
286 	 *   - The prefetch bias is a multiple of 2 words.
287 	 *   - The prefetch bias is less than one page.
288 	 */
289 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
290 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
291 
292 	off = PAGE_SIZE - pref_bias_clear_store;
293 	if (off > 0xffff || !pref_bias_clear_store)
294 		pg_addiu(&buf, A2, A0, off);
295 	else
296 		uasm_i_ori(&buf, A2, A0, off);
297 
298 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
299 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
300 
301 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
302 				* cache_line_size : 0;
303 	while (off) {
304 		build_clear_pref(&buf, -off);
305 		off -= cache_line_size;
306 	}
307 	uasm_l_clear_pref(&l, buf);
308 	do {
309 		build_clear_pref(&buf, off);
310 		build_clear_store(&buf, off);
311 		off += clear_word_size;
312 	} while (off < half_clear_loop_size);
313 	pg_addiu(&buf, A0, A0, 2 * off);
314 	off = -off;
315 	do {
316 		build_clear_pref(&buf, off);
317 		if (off == -clear_word_size)
318 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
319 		build_clear_store(&buf, off);
320 		off += clear_word_size;
321 	} while (off < 0);
322 
323 	if (pref_bias_clear_store) {
324 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
325 		uasm_l_clear_nopref(&l, buf);
326 		off = 0;
327 		do {
328 			build_clear_store(&buf, off);
329 			off += clear_word_size;
330 		} while (off < half_clear_loop_size);
331 		pg_addiu(&buf, A0, A0, 2 * off);
332 		off = -off;
333 		do {
334 			if (off == -clear_word_size)
335 				uasm_il_bne(&buf, &r, A0, A2,
336 					    label_clear_nopref);
337 			build_clear_store(&buf, off);
338 			off += clear_word_size;
339 		} while (off < 0);
340 	}
341 
342 	uasm_i_jr(&buf, RA);
343 	uasm_i_nop(&buf);
344 
345 	BUG_ON(buf > &__clear_page_end);
346 
347 	uasm_resolve_relocs(relocs, labels);
348 
349 	pr_debug("Synthesized clear page handler (%u instructions).\n",
350 		 (u32)(buf - &__clear_page_start));
351 
352 	pr_debug("\t.set push\n");
353 	pr_debug("\t.set noreorder\n");
354 	for (i = 0; i < (buf - &__clear_page_start); i++)
355 		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
356 	pr_debug("\t.set pop\n");
357 }
358 
build_copy_load(u32 ** buf,int reg,int off)359 static void build_copy_load(u32 **buf, int reg, int off)
360 {
361 	if (cpu_has_64bit_gp_regs) {
362 		uasm_i_ld(buf, reg, off, A1);
363 	} else {
364 		uasm_i_lw(buf, reg, off, A1);
365 	}
366 }
367 
build_copy_store(u32 ** buf,int reg,int off)368 static void build_copy_store(u32 **buf, int reg, int off)
369 {
370 	if (cpu_has_64bit_gp_regs) {
371 		uasm_i_sd(buf, reg, off, A0);
372 	} else {
373 		uasm_i_sw(buf, reg, off, A0);
374 	}
375 }
376 
build_copy_load_pref(u32 ** buf,int off)377 static inline void build_copy_load_pref(u32 **buf, int off)
378 {
379 	if (off & cache_line_mask())
380 		return;
381 
382 	if (pref_bias_copy_load)
383 		_uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
384 }
385 
build_copy_store_pref(u32 ** buf,int off)386 static inline void build_copy_store_pref(u32 **buf, int off)
387 {
388 	if (off & cache_line_mask())
389 		return;
390 
391 	if (pref_bias_copy_store) {
392 		_uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
393 			    A0);
394 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
395 		if (cpu_has_cache_cdex_s) {
396 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
397 		} else if (cpu_has_cache_cdex_p) {
398 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
399 				uasm_i_nop(buf);
400 				uasm_i_nop(buf);
401 				uasm_i_nop(buf);
402 				uasm_i_nop(buf);
403 			}
404 
405 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
406 				uasm_i_lw(buf, ZERO, ZERO, AT);
407 
408 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
409 		}
410 	}
411 }
412 
build_copy_page(void)413 void build_copy_page(void)
414 {
415 	int off;
416 	u32 *buf = &__copy_page_start;
417 	struct uasm_label *l = labels;
418 	struct uasm_reloc *r = relocs;
419 	int i;
420 	static atomic_t run_once = ATOMIC_INIT(0);
421 
422 	if (atomic_xchg(&run_once, 1)) {
423 		return;
424 	}
425 
426 	memset(labels, 0, sizeof(labels));
427 	memset(relocs, 0, sizeof(relocs));
428 
429 	set_prefetch_parameters();
430 
431 	/*
432 	 * This algorithm makes the following assumptions:
433 	 *   - All prefetch biases are multiples of 8 words.
434 	 *   - The prefetch biases are less than one page.
435 	 *   - The store prefetch bias isn't greater than the load
436 	 *     prefetch bias.
437 	 */
438 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
439 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
440 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
441 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
442 
443 	off = PAGE_SIZE - pref_bias_copy_load;
444 	if (off > 0xffff || !pref_bias_copy_load)
445 		pg_addiu(&buf, A2, A0, off);
446 	else
447 		uasm_i_ori(&buf, A2, A0, off);
448 
449 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
450 		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
451 
452 	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
453 				cache_line_size : 0;
454 	while (off) {
455 		build_copy_load_pref(&buf, -off);
456 		off -= cache_line_size;
457 	}
458 	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
459 				cache_line_size : 0;
460 	while (off) {
461 		build_copy_store_pref(&buf, -off);
462 		off -= cache_line_size;
463 	}
464 	uasm_l_copy_pref_both(&l, buf);
465 	do {
466 		build_copy_load_pref(&buf, off);
467 		build_copy_load(&buf, T0, off);
468 		build_copy_load_pref(&buf, off + copy_word_size);
469 		build_copy_load(&buf, T1, off + copy_word_size);
470 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
471 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
472 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
473 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
474 		build_copy_store_pref(&buf, off);
475 		build_copy_store(&buf, T0, off);
476 		build_copy_store_pref(&buf, off + copy_word_size);
477 		build_copy_store(&buf, T1, off + copy_word_size);
478 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
479 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
480 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
481 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
482 		off += 4 * copy_word_size;
483 	} while (off < half_copy_loop_size);
484 	pg_addiu(&buf, A1, A1, 2 * off);
485 	pg_addiu(&buf, A0, A0, 2 * off);
486 	off = -off;
487 	do {
488 		build_copy_load_pref(&buf, off);
489 		build_copy_load(&buf, T0, off);
490 		build_copy_load_pref(&buf, off + copy_word_size);
491 		build_copy_load(&buf, T1, off + copy_word_size);
492 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
493 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
494 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
495 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
496 		build_copy_store_pref(&buf, off);
497 		build_copy_store(&buf, T0, off);
498 		build_copy_store_pref(&buf, off + copy_word_size);
499 		build_copy_store(&buf, T1, off + copy_word_size);
500 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
501 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
502 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
503 		if (off == -(4 * copy_word_size))
504 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
505 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
506 		off += 4 * copy_word_size;
507 	} while (off < 0);
508 
509 	if (pref_bias_copy_load - pref_bias_copy_store) {
510 		pg_addiu(&buf, A2, A0,
511 			 pref_bias_copy_load - pref_bias_copy_store);
512 		uasm_l_copy_pref_store(&l, buf);
513 		off = 0;
514 		do {
515 			build_copy_load(&buf, T0, off);
516 			build_copy_load(&buf, T1, off + copy_word_size);
517 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
518 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
519 			build_copy_store_pref(&buf, off);
520 			build_copy_store(&buf, T0, off);
521 			build_copy_store_pref(&buf, off + copy_word_size);
522 			build_copy_store(&buf, T1, off + copy_word_size);
523 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
524 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
525 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
526 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
527 			off += 4 * copy_word_size;
528 		} while (off < half_copy_loop_size);
529 		pg_addiu(&buf, A1, A1, 2 * off);
530 		pg_addiu(&buf, A0, A0, 2 * off);
531 		off = -off;
532 		do {
533 			build_copy_load(&buf, T0, off);
534 			build_copy_load(&buf, T1, off + copy_word_size);
535 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
536 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
537 			build_copy_store_pref(&buf, off);
538 			build_copy_store(&buf, T0, off);
539 			build_copy_store_pref(&buf, off + copy_word_size);
540 			build_copy_store(&buf, T1, off + copy_word_size);
541 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
542 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
543 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
544 			if (off == -(4 * copy_word_size))
545 				uasm_il_bne(&buf, &r, A2, A0,
546 					    label_copy_pref_store);
547 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
548 			off += 4 * copy_word_size;
549 		} while (off < 0);
550 	}
551 
552 	if (pref_bias_copy_store) {
553 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
554 		uasm_l_copy_nopref(&l, buf);
555 		off = 0;
556 		do {
557 			build_copy_load(&buf, T0, off);
558 			build_copy_load(&buf, T1, off + copy_word_size);
559 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
560 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
561 			build_copy_store(&buf, T0, off);
562 			build_copy_store(&buf, T1, off + copy_word_size);
563 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
564 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
565 			off += 4 * copy_word_size;
566 		} while (off < half_copy_loop_size);
567 		pg_addiu(&buf, A1, A1, 2 * off);
568 		pg_addiu(&buf, A0, A0, 2 * off);
569 		off = -off;
570 		do {
571 			build_copy_load(&buf, T0, off);
572 			build_copy_load(&buf, T1, off + copy_word_size);
573 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
574 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
575 			build_copy_store(&buf, T0, off);
576 			build_copy_store(&buf, T1, off + copy_word_size);
577 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
578 			if (off == -(4 * copy_word_size))
579 				uasm_il_bne(&buf, &r, A2, A0,
580 					    label_copy_nopref);
581 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
582 			off += 4 * copy_word_size;
583 		} while (off < 0);
584 	}
585 
586 	uasm_i_jr(&buf, RA);
587 	uasm_i_nop(&buf);
588 
589 	BUG_ON(buf > &__copy_page_end);
590 
591 	uasm_resolve_relocs(relocs, labels);
592 
593 	pr_debug("Synthesized copy page handler (%u instructions).\n",
594 		 (u32)(buf - &__copy_page_start));
595 
596 	pr_debug("\t.set push\n");
597 	pr_debug("\t.set noreorder\n");
598 	for (i = 0; i < (buf - &__copy_page_start); i++)
599 		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
600 	pr_debug("\t.set pop\n");
601 }
602 
603 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
604 extern void clear_page_cpu(void *page);
605 extern void copy_page_cpu(void *to, void *from);
606 
607 /*
608  * Pad descriptors to cacheline, since each is exclusively owned by a
609  * particular CPU.
610  */
611 struct dmadscr {
612 	u64 dscr_a;
613 	u64 dscr_b;
614 	u64 pad_a;
615 	u64 pad_b;
616 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
617 
sb1_dma_init(void)618 void sb1_dma_init(void)
619 {
620 	int i;
621 
622 	for (i = 0; i < DM_NUM_CHANNELS; i++) {
623 		const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
624 				     V_DM_DSCR_BASE_RINGSZ(1);
625 		void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
626 
627 		__raw_writeq(base_val, base_reg);
628 		__raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
629 		__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
630 	}
631 }
632 
clear_page(void * page)633 void clear_page(void *page)
634 {
635 	u64 to_phys = CPHYSADDR((unsigned long)page);
636 	unsigned int cpu = smp_processor_id();
637 
638 	/* if the page is not in KSEG0, use old way */
639 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
640 		return clear_page_cpu(page);
641 
642 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
643 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
644 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
645 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
646 
647 	/*
648 	 * Don't really want to do it this way, but there's no
649 	 * reliable way to delay completion detection.
650 	 */
651 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
652 		 & M_DM_DSCR_BASE_INTERRUPT))
653 		;
654 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
655 }
656 
copy_page(void * to,void * from)657 void copy_page(void *to, void *from)
658 {
659 	u64 from_phys = CPHYSADDR((unsigned long)from);
660 	u64 to_phys = CPHYSADDR((unsigned long)to);
661 	unsigned int cpu = smp_processor_id();
662 
663 	/* if any page is not in KSEG0, use old way */
664 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
665 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
666 		return copy_page_cpu(to, from);
667 
668 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
669 				 M_DM_DSCRA_INTERRUPT;
670 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
671 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
672 
673 	/*
674 	 * Don't really want to do it this way, but there's no
675 	 * reliable way to delay completion detection.
676 	 */
677 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
678 		 & M_DM_DSCR_BASE_INTERRUPT))
679 		;
680 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
681 }
682 
683 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
684