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). */
54enum 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
62UASM_L_LA(_clear_nopref)
63UASM_L_LA(_clear_pref)
64UASM_L_LA(_copy_nopref)
65UASM_L_LA(_copy_pref_both)
66UASM_L_LA(_copy_pref_store)
67
68/* We need one branch and therefore one relocation per target label. */
69static struct uasm_label labels[5];
70static 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)		\
80do {						\
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
89static int pref_bias_clear_store;
90static int pref_bias_copy_load;
91static int pref_bias_copy_store;
92
93static u32 pref_src_mode;
94static u32 pref_dst_mode;
95
96static int clear_word_size;
97static int copy_word_size;
98
99static int half_clear_loop_size;
100static int half_copy_loop_size;
101
102static int cache_line_size;
103#define cache_line_mask() (cache_line_size - 1)
104
105static inline void
106pg_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
125static 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
225static 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
234static 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
261extern u32 __clear_page_start;
262extern u32 __clear_page_end;
263extern u32 __copy_page_start;
264extern u32 __copy_page_end;
265
266void 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
359static 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
368static 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
377static 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
386static 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
413void 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
604extern void clear_page_cpu(void *page);
605extern 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 */
611struct 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
618void 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
633void 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
657void 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