xref: /openbmc/linux/arch/mips/mm/page.c (revision f7777dcc)
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/init.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/smp.h>
15 #include <linux/mm.h>
16 #include <linux/module.h>
17 #include <linux/proc_fs.h>
18 
19 #include <asm/bugs.h>
20 #include <asm/cacheops.h>
21 #include <asm/cpu-type.h>
22 #include <asm/inst.h>
23 #include <asm/io.h>
24 #include <asm/page.h>
25 #include <asm/pgtable.h>
26 #include <asm/prefetch.h>
27 #include <asm/bootinfo.h>
28 #include <asm/mipsregs.h>
29 #include <asm/mmu_context.h>
30 #include <asm/cpu.h>
31 #include <asm/war.h>
32 
33 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
34 #include <asm/sibyte/sb1250.h>
35 #include <asm/sibyte/sb1250_regs.h>
36 #include <asm/sibyte/sb1250_dma.h>
37 #endif
38 
39 #include <asm/uasm.h>
40 
41 /* Registers used in the assembled routines. */
42 #define ZERO 0
43 #define AT 2
44 #define A0 4
45 #define A1 5
46 #define A2 6
47 #define T0 8
48 #define T1 9
49 #define T2 10
50 #define T3 11
51 #define T9 25
52 #define RA 31
53 
54 /* Handle labels (which must be positive integers). */
55 enum label_id {
56 	label_clear_nopref = 1,
57 	label_clear_pref,
58 	label_copy_nopref,
59 	label_copy_pref_both,
60 	label_copy_pref_store,
61 };
62 
63 UASM_L_LA(_clear_nopref)
64 UASM_L_LA(_clear_pref)
65 UASM_L_LA(_copy_nopref)
66 UASM_L_LA(_copy_pref_both)
67 UASM_L_LA(_copy_pref_store)
68 
69 /* We need one branch and therefore one relocation per target label. */
70 static struct uasm_label labels[5];
71 static struct uasm_reloc relocs[5];
72 
73 #define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
74 #define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
75 
76 static int pref_bias_clear_store;
77 static int pref_bias_copy_load;
78 static int pref_bias_copy_store;
79 
80 static u32 pref_src_mode;
81 static u32 pref_dst_mode;
82 
83 static int clear_word_size;
84 static int copy_word_size;
85 
86 static int half_clear_loop_size;
87 static int half_copy_loop_size;
88 
89 static int cache_line_size;
90 #define cache_line_mask() (cache_line_size - 1)
91 
92 static inline void
93 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
94 {
95 	if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
96 		if (off > 0x7fff) {
97 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
98 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
99 		} else
100 			uasm_i_addiu(buf, T9, ZERO, off);
101 		uasm_i_daddu(buf, reg1, reg2, T9);
102 	} else {
103 		if (off > 0x7fff) {
104 			uasm_i_lui(buf, T9, uasm_rel_hi(off));
105 			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
106 			UASM_i_ADDU(buf, reg1, reg2, T9);
107 		} else
108 			UASM_i_ADDIU(buf, reg1, reg2, off);
109 	}
110 }
111 
112 static void set_prefetch_parameters(void)
113 {
114 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
115 		clear_word_size = 8;
116 	else
117 		clear_word_size = 4;
118 
119 	if (cpu_has_64bit_gp_regs)
120 		copy_word_size = 8;
121 	else
122 		copy_word_size = 4;
123 
124 	/*
125 	 * The pref's used here are using "streaming" hints, which cause the
126 	 * copied data to be kicked out of the cache sooner.  A page copy often
127 	 * ends up copying a lot more data than is commonly used, so this seems
128 	 * to make sense in terms of reducing cache pollution, but I've no real
129 	 * performance data to back this up.
130 	 */
131 	if (cpu_has_prefetch) {
132 		/*
133 		 * XXX: Most prefetch bias values in here are based on
134 		 * guesswork.
135 		 */
136 		cache_line_size = cpu_dcache_line_size();
137 		switch (current_cpu_type()) {
138 		case CPU_R5500:
139 		case CPU_TX49XX:
140 			/* These processors only support the Pref_Load. */
141 			pref_bias_copy_load = 256;
142 			break;
143 
144 		case CPU_R10000:
145 		case CPU_R12000:
146 		case CPU_R14000:
147 			/*
148 			 * Those values have been experimentally tuned for an
149 			 * Origin 200.
150 			 */
151 			pref_bias_clear_store = 512;
152 			pref_bias_copy_load = 256;
153 			pref_bias_copy_store = 256;
154 			pref_src_mode = Pref_LoadStreamed;
155 			pref_dst_mode = Pref_StoreStreamed;
156 			break;
157 
158 		case CPU_SB1:
159 		case CPU_SB1A:
160 			pref_bias_clear_store = 128;
161 			pref_bias_copy_load = 128;
162 			pref_bias_copy_store = 128;
163 			/*
164 			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
165 			 * hints are broken.
166 			 */
167 			if (current_cpu_type() == CPU_SB1 &&
168 			    (current_cpu_data.processor_id & 0xff) < 0x02) {
169 				pref_src_mode = Pref_Load;
170 				pref_dst_mode = Pref_Store;
171 			} else {
172 				pref_src_mode = Pref_LoadStreamed;
173 				pref_dst_mode = Pref_StoreStreamed;
174 			}
175 			break;
176 
177 		default:
178 			pref_bias_clear_store = 128;
179 			pref_bias_copy_load = 256;
180 			pref_bias_copy_store = 128;
181 			pref_src_mode = Pref_LoadStreamed;
182 			pref_dst_mode = Pref_PrepareForStore;
183 			break;
184 		}
185 	} else {
186 		if (cpu_has_cache_cdex_s)
187 			cache_line_size = cpu_scache_line_size();
188 		else if (cpu_has_cache_cdex_p)
189 			cache_line_size = cpu_dcache_line_size();
190 	}
191 	/*
192 	 * Too much unrolling will overflow the available space in
193 	 * clear_space_array / copy_page_array.
194 	 */
195 	half_clear_loop_size = min(16 * clear_word_size,
196 				   max(cache_line_size >> 1,
197 				       4 * clear_word_size));
198 	half_copy_loop_size = min(16 * copy_word_size,
199 				  max(cache_line_size >> 1,
200 				      4 * copy_word_size));
201 }
202 
203 static void build_clear_store(u32 **buf, int off)
204 {
205 	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
206 		uasm_i_sd(buf, ZERO, off, A0);
207 	} else {
208 		uasm_i_sw(buf, ZERO, off, A0);
209 	}
210 }
211 
212 static inline void build_clear_pref(u32 **buf, int off)
213 {
214 	if (off & cache_line_mask())
215 		return;
216 
217 	if (pref_bias_clear_store) {
218 		uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
219 			    A0);
220 	} else if (cache_line_size == (half_clear_loop_size << 1)) {
221 		if (cpu_has_cache_cdex_s) {
222 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
223 		} else if (cpu_has_cache_cdex_p) {
224 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
225 				uasm_i_nop(buf);
226 				uasm_i_nop(buf);
227 				uasm_i_nop(buf);
228 				uasm_i_nop(buf);
229 			}
230 
231 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
232 				uasm_i_lw(buf, ZERO, ZERO, AT);
233 
234 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
235 		}
236 	}
237 }
238 
239 extern u32 __clear_page_start;
240 extern u32 __clear_page_end;
241 extern u32 __copy_page_start;
242 extern u32 __copy_page_end;
243 
244 void build_clear_page(void)
245 {
246 	int off;
247 	u32 *buf = &__clear_page_start;
248 	struct uasm_label *l = labels;
249 	struct uasm_reloc *r = relocs;
250 	int i;
251 	static atomic_t run_once = ATOMIC_INIT(0);
252 
253 	if (atomic_xchg(&run_once, 1)) {
254 		return;
255 	}
256 
257 	memset(labels, 0, sizeof(labels));
258 	memset(relocs, 0, sizeof(relocs));
259 
260 	set_prefetch_parameters();
261 
262 	/*
263 	 * This algorithm makes the following assumptions:
264 	 *   - The prefetch bias is a multiple of 2 words.
265 	 *   - The prefetch bias is less than one page.
266 	 */
267 	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
268 	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
269 
270 	off = PAGE_SIZE - pref_bias_clear_store;
271 	if (off > 0xffff || !pref_bias_clear_store)
272 		pg_addiu(&buf, A2, A0, off);
273 	else
274 		uasm_i_ori(&buf, A2, A0, off);
275 
276 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
277 		uasm_i_lui(&buf, AT, 0xa000);
278 
279 	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
280 				* cache_line_size : 0;
281 	while (off) {
282 		build_clear_pref(&buf, -off);
283 		off -= cache_line_size;
284 	}
285 	uasm_l_clear_pref(&l, buf);
286 	do {
287 		build_clear_pref(&buf, off);
288 		build_clear_store(&buf, off);
289 		off += clear_word_size;
290 	} while (off < half_clear_loop_size);
291 	pg_addiu(&buf, A0, A0, 2 * off);
292 	off = -off;
293 	do {
294 		build_clear_pref(&buf, off);
295 		if (off == -clear_word_size)
296 			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
297 		build_clear_store(&buf, off);
298 		off += clear_word_size;
299 	} while (off < 0);
300 
301 	if (pref_bias_clear_store) {
302 		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
303 		uasm_l_clear_nopref(&l, buf);
304 		off = 0;
305 		do {
306 			build_clear_store(&buf, off);
307 			off += clear_word_size;
308 		} while (off < half_clear_loop_size);
309 		pg_addiu(&buf, A0, A0, 2 * off);
310 		off = -off;
311 		do {
312 			if (off == -clear_word_size)
313 				uasm_il_bne(&buf, &r, A0, A2,
314 					    label_clear_nopref);
315 			build_clear_store(&buf, off);
316 			off += clear_word_size;
317 		} while (off < 0);
318 	}
319 
320 	uasm_i_jr(&buf, RA);
321 	uasm_i_nop(&buf);
322 
323 	BUG_ON(buf > &__clear_page_end);
324 
325 	uasm_resolve_relocs(relocs, labels);
326 
327 	pr_debug("Synthesized clear page handler (%u instructions).\n",
328 		 (u32)(buf - &__clear_page_start));
329 
330 	pr_debug("\t.set push\n");
331 	pr_debug("\t.set noreorder\n");
332 	for (i = 0; i < (buf - &__clear_page_start); i++)
333 		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
334 	pr_debug("\t.set pop\n");
335 }
336 
337 static void build_copy_load(u32 **buf, int reg, int off)
338 {
339 	if (cpu_has_64bit_gp_regs) {
340 		uasm_i_ld(buf, reg, off, A1);
341 	} else {
342 		uasm_i_lw(buf, reg, off, A1);
343 	}
344 }
345 
346 static void build_copy_store(u32 **buf, int reg, int off)
347 {
348 	if (cpu_has_64bit_gp_regs) {
349 		uasm_i_sd(buf, reg, off, A0);
350 	} else {
351 		uasm_i_sw(buf, reg, off, A0);
352 	}
353 }
354 
355 static inline void build_copy_load_pref(u32 **buf, int off)
356 {
357 	if (off & cache_line_mask())
358 		return;
359 
360 	if (pref_bias_copy_load)
361 		uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
362 }
363 
364 static inline void build_copy_store_pref(u32 **buf, int off)
365 {
366 	if (off & cache_line_mask())
367 		return;
368 
369 	if (pref_bias_copy_store) {
370 		uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
371 			    A0);
372 	} else if (cache_line_size == (half_copy_loop_size << 1)) {
373 		if (cpu_has_cache_cdex_s) {
374 			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
375 		} else if (cpu_has_cache_cdex_p) {
376 			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
377 				uasm_i_nop(buf);
378 				uasm_i_nop(buf);
379 				uasm_i_nop(buf);
380 				uasm_i_nop(buf);
381 			}
382 
383 			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
384 				uasm_i_lw(buf, ZERO, ZERO, AT);
385 
386 			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
387 		}
388 	}
389 }
390 
391 void build_copy_page(void)
392 {
393 	int off;
394 	u32 *buf = &__copy_page_start;
395 	struct uasm_label *l = labels;
396 	struct uasm_reloc *r = relocs;
397 	int i;
398 	static atomic_t run_once = ATOMIC_INIT(0);
399 
400 	if (atomic_xchg(&run_once, 1)) {
401 		return;
402 	}
403 
404 	memset(labels, 0, sizeof(labels));
405 	memset(relocs, 0, sizeof(relocs));
406 
407 	set_prefetch_parameters();
408 
409 	/*
410 	 * This algorithm makes the following assumptions:
411 	 *   - All prefetch biases are multiples of 8 words.
412 	 *   - The prefetch biases are less than one page.
413 	 *   - The store prefetch bias isn't greater than the load
414 	 *     prefetch bias.
415 	 */
416 	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
417 	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
418 	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
419 	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
420 
421 	off = PAGE_SIZE - pref_bias_copy_load;
422 	if (off > 0xffff || !pref_bias_copy_load)
423 		pg_addiu(&buf, A2, A0, off);
424 	else
425 		uasm_i_ori(&buf, A2, A0, off);
426 
427 	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
428 		uasm_i_lui(&buf, AT, 0xa000);
429 
430 	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
431 				cache_line_size : 0;
432 	while (off) {
433 		build_copy_load_pref(&buf, -off);
434 		off -= cache_line_size;
435 	}
436 	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
437 				cache_line_size : 0;
438 	while (off) {
439 		build_copy_store_pref(&buf, -off);
440 		off -= cache_line_size;
441 	}
442 	uasm_l_copy_pref_both(&l, buf);
443 	do {
444 		build_copy_load_pref(&buf, off);
445 		build_copy_load(&buf, T0, off);
446 		build_copy_load_pref(&buf, off + copy_word_size);
447 		build_copy_load(&buf, T1, off + copy_word_size);
448 		build_copy_load_pref(&buf, off + 2 * copy_word_size);
449 		build_copy_load(&buf, T2, off + 2 * copy_word_size);
450 		build_copy_load_pref(&buf, off + 3 * copy_word_size);
451 		build_copy_load(&buf, T3, off + 3 * copy_word_size);
452 		build_copy_store_pref(&buf, off);
453 		build_copy_store(&buf, T0, off);
454 		build_copy_store_pref(&buf, off + copy_word_size);
455 		build_copy_store(&buf, T1, off + copy_word_size);
456 		build_copy_store_pref(&buf, off + 2 * copy_word_size);
457 		build_copy_store(&buf, T2, off + 2 * copy_word_size);
458 		build_copy_store_pref(&buf, off + 3 * copy_word_size);
459 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
460 		off += 4 * copy_word_size;
461 	} while (off < half_copy_loop_size);
462 	pg_addiu(&buf, A1, A1, 2 * off);
463 	pg_addiu(&buf, A0, A0, 2 * off);
464 	off = -off;
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 		if (off == -(4 * copy_word_size))
482 			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
483 		build_copy_store(&buf, T3, off + 3 * copy_word_size);
484 		off += 4 * copy_word_size;
485 	} while (off < 0);
486 
487 	if (pref_bias_copy_load - pref_bias_copy_store) {
488 		pg_addiu(&buf, A2, A0,
489 			 pref_bias_copy_load - pref_bias_copy_store);
490 		uasm_l_copy_pref_store(&l, buf);
491 		off = 0;
492 		do {
493 			build_copy_load(&buf, T0, off);
494 			build_copy_load(&buf, T1, off + copy_word_size);
495 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
496 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
497 			build_copy_store_pref(&buf, off);
498 			build_copy_store(&buf, T0, off);
499 			build_copy_store_pref(&buf, off + copy_word_size);
500 			build_copy_store(&buf, T1, off + copy_word_size);
501 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
502 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
503 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
504 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
505 			off += 4 * copy_word_size;
506 		} while (off < half_copy_loop_size);
507 		pg_addiu(&buf, A1, A1, 2 * off);
508 		pg_addiu(&buf, A0, A0, 2 * off);
509 		off = -off;
510 		do {
511 			build_copy_load(&buf, T0, off);
512 			build_copy_load(&buf, T1, off + copy_word_size);
513 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
514 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
515 			build_copy_store_pref(&buf, off);
516 			build_copy_store(&buf, T0, off);
517 			build_copy_store_pref(&buf, off + copy_word_size);
518 			build_copy_store(&buf, T1, off + copy_word_size);
519 			build_copy_store_pref(&buf, off + 2 * copy_word_size);
520 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
521 			build_copy_store_pref(&buf, off + 3 * copy_word_size);
522 			if (off == -(4 * copy_word_size))
523 				uasm_il_bne(&buf, &r, A2, A0,
524 					    label_copy_pref_store);
525 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
526 			off += 4 * copy_word_size;
527 		} while (off < 0);
528 	}
529 
530 	if (pref_bias_copy_store) {
531 		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
532 		uasm_l_copy_nopref(&l, buf);
533 		off = 0;
534 		do {
535 			build_copy_load(&buf, T0, off);
536 			build_copy_load(&buf, T1, off + copy_word_size);
537 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
538 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
539 			build_copy_store(&buf, T0, off);
540 			build_copy_store(&buf, T1, off + copy_word_size);
541 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
542 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
543 			off += 4 * copy_word_size;
544 		} while (off < half_copy_loop_size);
545 		pg_addiu(&buf, A1, A1, 2 * off);
546 		pg_addiu(&buf, A0, A0, 2 * off);
547 		off = -off;
548 		do {
549 			build_copy_load(&buf, T0, off);
550 			build_copy_load(&buf, T1, off + copy_word_size);
551 			build_copy_load(&buf, T2, off + 2 * copy_word_size);
552 			build_copy_load(&buf, T3, off + 3 * copy_word_size);
553 			build_copy_store(&buf, T0, off);
554 			build_copy_store(&buf, T1, off + copy_word_size);
555 			build_copy_store(&buf, T2, off + 2 * copy_word_size);
556 			if (off == -(4 * copy_word_size))
557 				uasm_il_bne(&buf, &r, A2, A0,
558 					    label_copy_nopref);
559 			build_copy_store(&buf, T3, off + 3 * copy_word_size);
560 			off += 4 * copy_word_size;
561 		} while (off < 0);
562 	}
563 
564 	uasm_i_jr(&buf, RA);
565 	uasm_i_nop(&buf);
566 
567 	BUG_ON(buf > &__copy_page_end);
568 
569 	uasm_resolve_relocs(relocs, labels);
570 
571 	pr_debug("Synthesized copy page handler (%u instructions).\n",
572 		 (u32)(buf - &__copy_page_start));
573 
574 	pr_debug("\t.set push\n");
575 	pr_debug("\t.set noreorder\n");
576 	for (i = 0; i < (buf - &__copy_page_start); i++)
577 		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
578 	pr_debug("\t.set pop\n");
579 }
580 
581 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
582 extern void clear_page_cpu(void *page);
583 extern void copy_page_cpu(void *to, void *from);
584 
585 /*
586  * Pad descriptors to cacheline, since each is exclusively owned by a
587  * particular CPU.
588  */
589 struct dmadscr {
590 	u64 dscr_a;
591 	u64 dscr_b;
592 	u64 pad_a;
593 	u64 pad_b;
594 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
595 
596 void sb1_dma_init(void)
597 {
598 	int i;
599 
600 	for (i = 0; i < DM_NUM_CHANNELS; i++) {
601 		const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
602 				     V_DM_DSCR_BASE_RINGSZ(1);
603 		void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
604 
605 		__raw_writeq(base_val, base_reg);
606 		__raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
607 		__raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
608 	}
609 }
610 
611 void clear_page(void *page)
612 {
613 	u64 to_phys = CPHYSADDR((unsigned long)page);
614 	unsigned int cpu = smp_processor_id();
615 
616 	/* if the page is not in KSEG0, use old way */
617 	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
618 		return clear_page_cpu(page);
619 
620 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
621 				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
622 	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
623 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
624 
625 	/*
626 	 * Don't really want to do it this way, but there's no
627 	 * reliable way to delay completion detection.
628 	 */
629 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
630 		 & M_DM_DSCR_BASE_INTERRUPT))
631 		;
632 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
633 }
634 
635 void copy_page(void *to, void *from)
636 {
637 	u64 from_phys = CPHYSADDR((unsigned long)from);
638 	u64 to_phys = CPHYSADDR((unsigned long)to);
639 	unsigned int cpu = smp_processor_id();
640 
641 	/* if any page is not in KSEG0, use old way */
642 	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
643 	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
644 		return copy_page_cpu(to, from);
645 
646 	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
647 				 M_DM_DSCRA_INTERRUPT;
648 	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
649 	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
650 
651 	/*
652 	 * Don't really want to do it this way, but there's no
653 	 * reliable way to delay completion detection.
654 	 */
655 	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
656 		 & M_DM_DSCR_BASE_INTERRUPT))
657 		;
658 	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
659 }
660 
661 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
662