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v6.2
  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/proc_fs.h>
 16
 17#include <asm/bugs.h>
 18#include <asm/cacheops.h>
 19#include <asm/cpu-type.h>
 20#include <asm/inst.h>
 21#include <asm/io.h>
 22#include <asm/page.h>
 23#include <asm/prefetch.h>
 24#include <asm/bootinfo.h>
 25#include <asm/mipsregs.h>
 26#include <asm/mmu_context.h>
 27#include <asm/cpu.h>
 
 28
 29#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 30#include <asm/sibyte/sb1250.h>
 31#include <asm/sibyte/sb1250_regs.h>
 32#include <asm/sibyte/sb1250_dma.h>
 33#endif
 34
 35#include <asm/uasm.h>
 36
 37/* Registers used in the assembled routines. */
 38#define ZERO 0
 39#define AT 2
 40#define A0 4
 41#define A1 5
 42#define A2 6
 43#define T0 8
 44#define T1 9
 45#define T2 10
 46#define T3 11
 47#define T9 25
 48#define RA 31
 49
 50/* Handle labels (which must be positive integers). */
 51enum label_id {
 52	label_clear_nopref = 1,
 53	label_clear_pref,
 54	label_copy_nopref,
 55	label_copy_pref_both,
 56	label_copy_pref_store,
 57};
 58
 59UASM_L_LA(_clear_nopref)
 60UASM_L_LA(_clear_pref)
 61UASM_L_LA(_copy_nopref)
 62UASM_L_LA(_copy_pref_both)
 63UASM_L_LA(_copy_pref_store)
 64
 65/* We need one branch and therefore one relocation per target label. */
 66static struct uasm_label labels[5];
 67static struct uasm_reloc relocs[5];
 68
 69#define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
 70#define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
 71
 72/*
 73 * R6 has a limited offset of the pref instruction.
 74 * Skip it if the offset is more than 9 bits.
 75 */
 76#define _uasm_i_pref(a, b, c, d)		\
 77do {						\
 78	if (cpu_has_mips_r6) {			\
 79		if (c <= 0xff && c >= -0x100)	\
 80			uasm_i_pref(a, b, c, d);\
 81	} else {				\
 82		uasm_i_pref(a, b, c, d);	\
 83	}					\
 84} while(0)
 85
 86static int pref_bias_clear_store;
 87static int pref_bias_copy_load;
 88static int pref_bias_copy_store;
 89
 90static u32 pref_src_mode;
 91static u32 pref_dst_mode;
 92
 93static int clear_word_size;
 94static int copy_word_size;
 95
 96static int half_clear_loop_size;
 97static int half_copy_loop_size;
 98
 99static int cache_line_size;
100#define cache_line_mask() (cache_line_size - 1)
101
102static inline void
103pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
104{
105	if (cpu_has_64bit_gp_regs &&
106	    IS_ENABLED(CONFIG_CPU_DADDI_WORKAROUNDS) &&
107	    r4k_daddiu_bug()) {
108		if (off > 0x7fff) {
109			uasm_i_lui(buf, T9, uasm_rel_hi(off));
110			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
111		} else
112			uasm_i_addiu(buf, T9, ZERO, off);
113		uasm_i_daddu(buf, reg1, reg2, T9);
114	} else {
115		if (off > 0x7fff) {
116			uasm_i_lui(buf, T9, uasm_rel_hi(off));
117			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
118			UASM_i_ADDU(buf, reg1, reg2, T9);
119		} else
120			UASM_i_ADDIU(buf, reg1, reg2, off);
121	}
122}
123
124static void set_prefetch_parameters(void)
125{
126	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
127		clear_word_size = 8;
128	else
129		clear_word_size = 4;
130
131	if (cpu_has_64bit_gp_regs)
132		copy_word_size = 8;
133	else
134		copy_word_size = 4;
135
136	/*
137	 * The pref's used here are using "streaming" hints, which cause the
138	 * copied data to be kicked out of the cache sooner.  A page copy often
139	 * ends up copying a lot more data than is commonly used, so this seems
140	 * to make sense in terms of reducing cache pollution, but I've no real
141	 * performance data to back this up.
142	 */
143	if (cpu_has_prefetch) {
144		/*
145		 * XXX: Most prefetch bias values in here are based on
146		 * guesswork.
147		 */
148		cache_line_size = cpu_dcache_line_size();
149		switch (current_cpu_type()) {
150		case CPU_R5500:
151		case CPU_TX49XX:
152			/* These processors only support the Pref_Load. */
153			pref_bias_copy_load = 256;
154			break;
155
156		case CPU_R10000:
157		case CPU_R12000:
158		case CPU_R14000:
159		case CPU_R16000:
160			/*
161			 * Those values have been experimentally tuned for an
162			 * Origin 200.
163			 */
164			pref_bias_clear_store = 512;
165			pref_bias_copy_load = 256;
166			pref_bias_copy_store = 256;
167			pref_src_mode = Pref_LoadStreamed;
168			pref_dst_mode = Pref_StoreStreamed;
169			break;
170
171		case CPU_SB1:
172		case CPU_SB1A:
173			pref_bias_clear_store = 128;
174			pref_bias_copy_load = 128;
175			pref_bias_copy_store = 128;
176			/*
177			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
178			 * hints are broken.
179			 */
180			if (current_cpu_type() == CPU_SB1 &&
181			    (current_cpu_data.processor_id & 0xff) < 0x02) {
182				pref_src_mode = Pref_Load;
183				pref_dst_mode = Pref_Store;
184			} else {
185				pref_src_mode = Pref_LoadStreamed;
186				pref_dst_mode = Pref_StoreStreamed;
187			}
188			break;
189
190		case CPU_LOONGSON64:
191			/* Loongson-3 only support the Pref_Load/Pref_Store. */
192			pref_bias_clear_store = 128;
193			pref_bias_copy_load = 128;
194			pref_bias_copy_store = 128;
195			pref_src_mode = Pref_Load;
196			pref_dst_mode = Pref_Store;
197			break;
198
199		default:
200			pref_bias_clear_store = 128;
201			pref_bias_copy_load = 256;
202			pref_bias_copy_store = 128;
203			pref_src_mode = Pref_LoadStreamed;
204			if (cpu_has_mips_r6)
205				/*
206				 * Bit 30 (Pref_PrepareForStore) has been
207				 * removed from MIPS R6. Use bit 5
208				 * (Pref_StoreStreamed).
209				 */
210				pref_dst_mode = Pref_StoreStreamed;
211			else
212				pref_dst_mode = Pref_PrepareForStore;
213			break;
214		}
215	} else {
216		if (cpu_has_cache_cdex_s)
217			cache_line_size = cpu_scache_line_size();
218		else if (cpu_has_cache_cdex_p)
219			cache_line_size = cpu_dcache_line_size();
220	}
221	/*
222	 * Too much unrolling will overflow the available space in
223	 * clear_space_array / copy_page_array.
224	 */
225	half_clear_loop_size = min(16 * clear_word_size,
226				   max(cache_line_size >> 1,
227				       4 * clear_word_size));
228	half_copy_loop_size = min(16 * copy_word_size,
229				  max(cache_line_size >> 1,
230				      4 * copy_word_size));
231}
232
233static void build_clear_store(u32 **buf, int off)
234{
235	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
236		uasm_i_sd(buf, ZERO, off, A0);
237	} else {
238		uasm_i_sw(buf, ZERO, off, A0);
239	}
240}
241
242static inline void build_clear_pref(u32 **buf, int off)
243{
244	if (off & cache_line_mask())
245		return;
246
247	if (pref_bias_clear_store) {
248		_uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
249			    A0);
250	} else if (cache_line_size == (half_clear_loop_size << 1)) {
251		if (cpu_has_cache_cdex_s) {
252			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
253		} else if (cpu_has_cache_cdex_p) {
254			if (IS_ENABLED(CONFIG_WAR_R4600_V1_HIT_CACHEOP) &&
255			    cpu_is_r4600_v1_x()) {
256				uasm_i_nop(buf);
257				uasm_i_nop(buf);
258				uasm_i_nop(buf);
259				uasm_i_nop(buf);
260			}
261
262			if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) &&
263			    cpu_is_r4600_v2_x())
264				uasm_i_lw(buf, ZERO, ZERO, AT);
265
266			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
267		}
268	}
269}
270
271extern u32 __clear_page_start;
272extern u32 __clear_page_end;
273extern u32 __copy_page_start;
274extern u32 __copy_page_end;
275
276void build_clear_page(void)
277{
278	int off;
279	u32 *buf = &__clear_page_start;
280	struct uasm_label *l = labels;
281	struct uasm_reloc *r = relocs;
282	int i;
283	static atomic_t run_once = ATOMIC_INIT(0);
284
285	if (atomic_xchg(&run_once, 1)) {
286		return;
287	}
288
289	memset(labels, 0, sizeof(labels));
290	memset(relocs, 0, sizeof(relocs));
291
292	set_prefetch_parameters();
293
294	/*
295	 * This algorithm makes the following assumptions:
296	 *   - The prefetch bias is a multiple of 2 words.
297	 *   - The prefetch bias is less than one page.
298	 */
299	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
300	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
301
302	off = PAGE_SIZE - pref_bias_clear_store;
303	if (off > 0xffff || !pref_bias_clear_store)
304		pg_addiu(&buf, A2, A0, off);
305	else
306		uasm_i_ori(&buf, A2, A0, off);
307
308	if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) && cpu_is_r4600_v2_x())
309		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
310
311	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
312				* cache_line_size : 0;
313	while (off) {
314		build_clear_pref(&buf, -off);
315		off -= cache_line_size;
316	}
317	uasm_l_clear_pref(&l, buf);
318	do {
319		build_clear_pref(&buf, off);
320		build_clear_store(&buf, off);
321		off += clear_word_size;
322	} while (off < half_clear_loop_size);
323	pg_addiu(&buf, A0, A0, 2 * off);
324	off = -off;
325	do {
326		build_clear_pref(&buf, off);
327		if (off == -clear_word_size)
328			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
329		build_clear_store(&buf, off);
330		off += clear_word_size;
331	} while (off < 0);
332
333	if (pref_bias_clear_store) {
334		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
335		uasm_l_clear_nopref(&l, buf);
336		off = 0;
337		do {
338			build_clear_store(&buf, off);
339			off += clear_word_size;
340		} while (off < half_clear_loop_size);
341		pg_addiu(&buf, A0, A0, 2 * off);
342		off = -off;
343		do {
344			if (off == -clear_word_size)
345				uasm_il_bne(&buf, &r, A0, A2,
346					    label_clear_nopref);
347			build_clear_store(&buf, off);
348			off += clear_word_size;
349		} while (off < 0);
350	}
351
352	uasm_i_jr(&buf, RA);
353	uasm_i_nop(&buf);
354
355	BUG_ON(buf > &__clear_page_end);
356
357	uasm_resolve_relocs(relocs, labels);
358
359	pr_debug("Synthesized clear page handler (%u instructions).\n",
360		 (u32)(buf - &__clear_page_start));
361
362	pr_debug("\t.set push\n");
363	pr_debug("\t.set noreorder\n");
364	for (i = 0; i < (buf - &__clear_page_start); i++)
365		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
366	pr_debug("\t.set pop\n");
367}
368
369static void build_copy_load(u32 **buf, int reg, int off)
370{
371	if (cpu_has_64bit_gp_regs) {
372		uasm_i_ld(buf, reg, off, A1);
373	} else {
374		uasm_i_lw(buf, reg, off, A1);
375	}
376}
377
378static void build_copy_store(u32 **buf, int reg, int off)
379{
380	if (cpu_has_64bit_gp_regs) {
381		uasm_i_sd(buf, reg, off, A0);
382	} else {
383		uasm_i_sw(buf, reg, off, A0);
384	}
385}
386
387static inline void build_copy_load_pref(u32 **buf, int off)
388{
389	if (off & cache_line_mask())
390		return;
391
392	if (pref_bias_copy_load)
393		_uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
394}
395
396static inline void build_copy_store_pref(u32 **buf, int off)
397{
398	if (off & cache_line_mask())
399		return;
400
401	if (pref_bias_copy_store) {
402		_uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
403			    A0);
404	} else if (cache_line_size == (half_copy_loop_size << 1)) {
405		if (cpu_has_cache_cdex_s) {
406			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
407		} else if (cpu_has_cache_cdex_p) {
408			if (IS_ENABLED(CONFIG_WAR_R4600_V1_HIT_CACHEOP) &&
409			    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 (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) &&
417			    cpu_is_r4600_v2_x())
418				uasm_i_lw(buf, ZERO, ZERO, AT);
419
420			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
421		}
422	}
423}
424
425void build_copy_page(void)
426{
427	int off;
428	u32 *buf = &__copy_page_start;
429	struct uasm_label *l = labels;
430	struct uasm_reloc *r = relocs;
431	int i;
432	static atomic_t run_once = ATOMIC_INIT(0);
433
434	if (atomic_xchg(&run_once, 1)) {
435		return;
436	}
437
438	memset(labels, 0, sizeof(labels));
439	memset(relocs, 0, sizeof(relocs));
440
441	set_prefetch_parameters();
442
443	/*
444	 * This algorithm makes the following assumptions:
445	 *   - All prefetch biases are multiples of 8 words.
446	 *   - The prefetch biases are less than one page.
447	 *   - The store prefetch bias isn't greater than the load
448	 *     prefetch bias.
449	 */
450	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
451	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
452	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
453	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
454
455	off = PAGE_SIZE - pref_bias_copy_load;
456	if (off > 0xffff || !pref_bias_copy_load)
457		pg_addiu(&buf, A2, A0, off);
458	else
459		uasm_i_ori(&buf, A2, A0, off);
460
461	if (IS_ENABLED(CONFIG_WAR_R4600_V2_HIT_CACHEOP) && cpu_is_r4600_v2_x())
462		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
463
464	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
465				cache_line_size : 0;
466	while (off) {
467		build_copy_load_pref(&buf, -off);
468		off -= cache_line_size;
469	}
470	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
471				cache_line_size : 0;
472	while (off) {
473		build_copy_store_pref(&buf, -off);
474		off -= cache_line_size;
475	}
476	uasm_l_copy_pref_both(&l, buf);
477	do {
478		build_copy_load_pref(&buf, off);
479		build_copy_load(&buf, T0, off);
480		build_copy_load_pref(&buf, off + copy_word_size);
481		build_copy_load(&buf, T1, off + copy_word_size);
482		build_copy_load_pref(&buf, off + 2 * copy_word_size);
483		build_copy_load(&buf, T2, off + 2 * copy_word_size);
484		build_copy_load_pref(&buf, off + 3 * copy_word_size);
485		build_copy_load(&buf, T3, off + 3 * copy_word_size);
486		build_copy_store_pref(&buf, off);
487		build_copy_store(&buf, T0, off);
488		build_copy_store_pref(&buf, off + copy_word_size);
489		build_copy_store(&buf, T1, off + copy_word_size);
490		build_copy_store_pref(&buf, off + 2 * copy_word_size);
491		build_copy_store(&buf, T2, off + 2 * copy_word_size);
492		build_copy_store_pref(&buf, off + 3 * copy_word_size);
493		build_copy_store(&buf, T3, off + 3 * copy_word_size);
494		off += 4 * copy_word_size;
495	} while (off < half_copy_loop_size);
496	pg_addiu(&buf, A1, A1, 2 * off);
497	pg_addiu(&buf, A0, A0, 2 * off);
498	off = -off;
499	do {
500		build_copy_load_pref(&buf, off);
501		build_copy_load(&buf, T0, off);
502		build_copy_load_pref(&buf, off + copy_word_size);
503		build_copy_load(&buf, T1, off + copy_word_size);
504		build_copy_load_pref(&buf, off + 2 * copy_word_size);
505		build_copy_load(&buf, T2, off + 2 * copy_word_size);
506		build_copy_load_pref(&buf, off + 3 * copy_word_size);
507		build_copy_load(&buf, T3, off + 3 * copy_word_size);
508		build_copy_store_pref(&buf, off);
509		build_copy_store(&buf, T0, off);
510		build_copy_store_pref(&buf, off + copy_word_size);
511		build_copy_store(&buf, T1, off + copy_word_size);
512		build_copy_store_pref(&buf, off + 2 * copy_word_size);
513		build_copy_store(&buf, T2, off + 2 * copy_word_size);
514		build_copy_store_pref(&buf, off + 3 * copy_word_size);
515		if (off == -(4 * copy_word_size))
516			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
517		build_copy_store(&buf, T3, off + 3 * copy_word_size);
518		off += 4 * copy_word_size;
519	} while (off < 0);
520
521	if (pref_bias_copy_load - pref_bias_copy_store) {
522		pg_addiu(&buf, A2, A0,
523			 pref_bias_copy_load - pref_bias_copy_store);
524		uasm_l_copy_pref_store(&l, buf);
525		off = 0;
526		do {
527			build_copy_load(&buf, T0, off);
528			build_copy_load(&buf, T1, off + copy_word_size);
529			build_copy_load(&buf, T2, off + 2 * copy_word_size);
530			build_copy_load(&buf, T3, off + 3 * copy_word_size);
531			build_copy_store_pref(&buf, off);
532			build_copy_store(&buf, T0, off);
533			build_copy_store_pref(&buf, off + copy_word_size);
534			build_copy_store(&buf, T1, off + copy_word_size);
535			build_copy_store_pref(&buf, off + 2 * copy_word_size);
536			build_copy_store(&buf, T2, off + 2 * copy_word_size);
537			build_copy_store_pref(&buf, off + 3 * copy_word_size);
538			build_copy_store(&buf, T3, off + 3 * copy_word_size);
539			off += 4 * copy_word_size;
540		} while (off < half_copy_loop_size);
541		pg_addiu(&buf, A1, A1, 2 * off);
542		pg_addiu(&buf, A0, A0, 2 * off);
543		off = -off;
544		do {
545			build_copy_load(&buf, T0, off);
546			build_copy_load(&buf, T1, off + copy_word_size);
547			build_copy_load(&buf, T2, off + 2 * copy_word_size);
548			build_copy_load(&buf, T3, off + 3 * copy_word_size);
549			build_copy_store_pref(&buf, off);
550			build_copy_store(&buf, T0, off);
551			build_copy_store_pref(&buf, off + copy_word_size);
552			build_copy_store(&buf, T1, off + copy_word_size);
553			build_copy_store_pref(&buf, off + 2 * copy_word_size);
554			build_copy_store(&buf, T2, off + 2 * copy_word_size);
555			build_copy_store_pref(&buf, off + 3 * copy_word_size);
556			if (off == -(4 * copy_word_size))
557				uasm_il_bne(&buf, &r, A2, A0,
558					    label_copy_pref_store);
559			build_copy_store(&buf, T3, off + 3 * copy_word_size);
560			off += 4 * copy_word_size;
561		} while (off < 0);
562	}
563
564	if (pref_bias_copy_store) {
565		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
566		uasm_l_copy_nopref(&l, buf);
567		off = 0;
568		do {
569			build_copy_load(&buf, T0, off);
570			build_copy_load(&buf, T1, off + copy_word_size);
571			build_copy_load(&buf, T2, off + 2 * copy_word_size);
572			build_copy_load(&buf, T3, off + 3 * copy_word_size);
573			build_copy_store(&buf, T0, off);
574			build_copy_store(&buf, T1, off + copy_word_size);
575			build_copy_store(&buf, T2, off + 2 * copy_word_size);
576			build_copy_store(&buf, T3, off + 3 * copy_word_size);
577			off += 4 * copy_word_size;
578		} while (off < half_copy_loop_size);
579		pg_addiu(&buf, A1, A1, 2 * off);
580		pg_addiu(&buf, A0, A0, 2 * off);
581		off = -off;
582		do {
583			build_copy_load(&buf, T0, off);
584			build_copy_load(&buf, T1, off + copy_word_size);
585			build_copy_load(&buf, T2, off + 2 * copy_word_size);
586			build_copy_load(&buf, T3, off + 3 * copy_word_size);
587			build_copy_store(&buf, T0, off);
588			build_copy_store(&buf, T1, off + copy_word_size);
589			build_copy_store(&buf, T2, off + 2 * copy_word_size);
590			if (off == -(4 * copy_word_size))
591				uasm_il_bne(&buf, &r, A2, A0,
592					    label_copy_nopref);
593			build_copy_store(&buf, T3, off + 3 * copy_word_size);
594			off += 4 * copy_word_size;
595		} while (off < 0);
596	}
597
598	uasm_i_jr(&buf, RA);
599	uasm_i_nop(&buf);
600
601	BUG_ON(buf > &__copy_page_end);
602
603	uasm_resolve_relocs(relocs, labels);
604
605	pr_debug("Synthesized copy page handler (%u instructions).\n",
606		 (u32)(buf - &__copy_page_start));
607
608	pr_debug("\t.set push\n");
609	pr_debug("\t.set noreorder\n");
610	for (i = 0; i < (buf - &__copy_page_start); i++)
611		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
612	pr_debug("\t.set pop\n");
613}
614
615#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
616extern void clear_page_cpu(void *page);
617extern void copy_page_cpu(void *to, void *from);
618
619/*
620 * Pad descriptors to cacheline, since each is exclusively owned by a
621 * particular CPU.
622 */
623struct dmadscr {
624	u64 dscr_a;
625	u64 dscr_b;
626	u64 pad_a;
627	u64 pad_b;
628} ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
629
630void clear_page(void *page)
631{
632	u64 to_phys = CPHYSADDR((unsigned long)page);
633	unsigned int cpu = smp_processor_id();
634
635	/* if the page is not in KSEG0, use old way */
636	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
637		return clear_page_cpu(page);
638
639	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
640				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
641	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
642	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
643
644	/*
645	 * Don't really want to do it this way, but there's no
646	 * reliable way to delay completion detection.
647	 */
648	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
649		 & M_DM_DSCR_BASE_INTERRUPT))
650		;
651	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
652}
653EXPORT_SYMBOL(clear_page);
654
655void copy_page(void *to, void *from)
656{
657	u64 from_phys = CPHYSADDR((unsigned long)from);
658	u64 to_phys = CPHYSADDR((unsigned long)to);
659	unsigned int cpu = smp_processor_id();
660
661	/* if any page is not in KSEG0, use old way */
662	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
663	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
664		return copy_page_cpu(to, from);
665
666	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
667				 M_DM_DSCRA_INTERRUPT;
668	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
669	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
670
671	/*
672	 * Don't really want to do it this way, but there's no
673	 * reliable way to delay completion detection.
674	 */
675	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
676		 & M_DM_DSCR_BASE_INTERRUPT))
677		;
678	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
679}
680EXPORT_SYMBOL(copy_page);
681
682#endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
v5.9
  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/proc_fs.h>
 16
 17#include <asm/bugs.h>
 18#include <asm/cacheops.h>
 19#include <asm/cpu-type.h>
 20#include <asm/inst.h>
 21#include <asm/io.h>
 22#include <asm/page.h>
 23#include <asm/prefetch.h>
 24#include <asm/bootinfo.h>
 25#include <asm/mipsregs.h>
 26#include <asm/mmu_context.h>
 27#include <asm/cpu.h>
 28#include <asm/war.h>
 29
 30#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 31#include <asm/sibyte/sb1250.h>
 32#include <asm/sibyte/sb1250_regs.h>
 33#include <asm/sibyte/sb1250_dma.h>
 34#endif
 35
 36#include <asm/uasm.h>
 37
 38/* Registers used in the assembled routines. */
 39#define ZERO 0
 40#define AT 2
 41#define A0 4
 42#define A1 5
 43#define A2 6
 44#define T0 8
 45#define T1 9
 46#define T2 10
 47#define T3 11
 48#define T9 25
 49#define RA 31
 50
 51/* Handle labels (which must be positive integers). */
 52enum label_id {
 53	label_clear_nopref = 1,
 54	label_clear_pref,
 55	label_copy_nopref,
 56	label_copy_pref_both,
 57	label_copy_pref_store,
 58};
 59
 60UASM_L_LA(_clear_nopref)
 61UASM_L_LA(_clear_pref)
 62UASM_L_LA(_copy_nopref)
 63UASM_L_LA(_copy_pref_both)
 64UASM_L_LA(_copy_pref_store)
 65
 66/* We need one branch and therefore one relocation per target label. */
 67static struct uasm_label labels[5];
 68static struct uasm_reloc relocs[5];
 69
 70#define cpu_is_r4600_v1_x()	((read_c0_prid() & 0xfffffff0) == 0x00002010)
 71#define cpu_is_r4600_v2_x()	((read_c0_prid() & 0xfffffff0) == 0x00002020)
 72
 73/*
 74 * R6 has a limited offset of the pref instruction.
 75 * Skip it if the offset is more than 9 bits.
 76 */
 77#define _uasm_i_pref(a, b, c, d)		\
 78do {						\
 79	if (cpu_has_mips_r6) {			\
 80		if (c <= 0xff && c >= -0x100)	\
 81			uasm_i_pref(a, b, c, d);\
 82	} else {				\
 83		uasm_i_pref(a, b, c, d);	\
 84	}					\
 85} while(0)
 86
 87static int pref_bias_clear_store;
 88static int pref_bias_copy_load;
 89static int pref_bias_copy_store;
 90
 91static u32 pref_src_mode;
 92static u32 pref_dst_mode;
 93
 94static int clear_word_size;
 95static int copy_word_size;
 96
 97static int half_clear_loop_size;
 98static int half_copy_loop_size;
 99
100static int cache_line_size;
101#define cache_line_mask() (cache_line_size - 1)
102
103static inline void
104pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
105{
106	if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
 
 
107		if (off > 0x7fff) {
108			uasm_i_lui(buf, T9, uasm_rel_hi(off));
109			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
110		} else
111			uasm_i_addiu(buf, T9, ZERO, off);
112		uasm_i_daddu(buf, reg1, reg2, T9);
113	} else {
114		if (off > 0x7fff) {
115			uasm_i_lui(buf, T9, uasm_rel_hi(off));
116			uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
117			UASM_i_ADDU(buf, reg1, reg2, T9);
118		} else
119			UASM_i_ADDIU(buf, reg1, reg2, off);
120	}
121}
122
123static void set_prefetch_parameters(void)
124{
125	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
126		clear_word_size = 8;
127	else
128		clear_word_size = 4;
129
130	if (cpu_has_64bit_gp_regs)
131		copy_word_size = 8;
132	else
133		copy_word_size = 4;
134
135	/*
136	 * The pref's used here are using "streaming" hints, which cause the
137	 * copied data to be kicked out of the cache sooner.  A page copy often
138	 * ends up copying a lot more data than is commonly used, so this seems
139	 * to make sense in terms of reducing cache pollution, but I've no real
140	 * performance data to back this up.
141	 */
142	if (cpu_has_prefetch) {
143		/*
144		 * XXX: Most prefetch bias values in here are based on
145		 * guesswork.
146		 */
147		cache_line_size = cpu_dcache_line_size();
148		switch (current_cpu_type()) {
149		case CPU_R5500:
150		case CPU_TX49XX:
151			/* These processors only support the Pref_Load. */
152			pref_bias_copy_load = 256;
153			break;
154
155		case CPU_R10000:
156		case CPU_R12000:
157		case CPU_R14000:
158		case CPU_R16000:
159			/*
160			 * Those values have been experimentally tuned for an
161			 * Origin 200.
162			 */
163			pref_bias_clear_store = 512;
164			pref_bias_copy_load = 256;
165			pref_bias_copy_store = 256;
166			pref_src_mode = Pref_LoadStreamed;
167			pref_dst_mode = Pref_StoreStreamed;
168			break;
169
170		case CPU_SB1:
171		case CPU_SB1A:
172			pref_bias_clear_store = 128;
173			pref_bias_copy_load = 128;
174			pref_bias_copy_store = 128;
175			/*
176			 * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
177			 * hints are broken.
178			 */
179			if (current_cpu_type() == CPU_SB1 &&
180			    (current_cpu_data.processor_id & 0xff) < 0x02) {
181				pref_src_mode = Pref_Load;
182				pref_dst_mode = Pref_Store;
183			} else {
184				pref_src_mode = Pref_LoadStreamed;
185				pref_dst_mode = Pref_StoreStreamed;
186			}
187			break;
188
189		case CPU_LOONGSON64:
190			/* Loongson-3 only support the Pref_Load/Pref_Store. */
191			pref_bias_clear_store = 128;
192			pref_bias_copy_load = 128;
193			pref_bias_copy_store = 128;
194			pref_src_mode = Pref_Load;
195			pref_dst_mode = Pref_Store;
196			break;
197
198		default:
199			pref_bias_clear_store = 128;
200			pref_bias_copy_load = 256;
201			pref_bias_copy_store = 128;
202			pref_src_mode = Pref_LoadStreamed;
203			if (cpu_has_mips_r6)
204				/*
205				 * Bit 30 (Pref_PrepareForStore) has been
206				 * removed from MIPS R6. Use bit 5
207				 * (Pref_StoreStreamed).
208				 */
209				pref_dst_mode = Pref_StoreStreamed;
210			else
211				pref_dst_mode = Pref_PrepareForStore;
212			break;
213		}
214	} else {
215		if (cpu_has_cache_cdex_s)
216			cache_line_size = cpu_scache_line_size();
217		else if (cpu_has_cache_cdex_p)
218			cache_line_size = cpu_dcache_line_size();
219	}
220	/*
221	 * Too much unrolling will overflow the available space in
222	 * clear_space_array / copy_page_array.
223	 */
224	half_clear_loop_size = min(16 * clear_word_size,
225				   max(cache_line_size >> 1,
226				       4 * clear_word_size));
227	half_copy_loop_size = min(16 * copy_word_size,
228				  max(cache_line_size >> 1,
229				      4 * copy_word_size));
230}
231
232static void build_clear_store(u32 **buf, int off)
233{
234	if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
235		uasm_i_sd(buf, ZERO, off, A0);
236	} else {
237		uasm_i_sw(buf, ZERO, off, A0);
238	}
239}
240
241static inline void build_clear_pref(u32 **buf, int off)
242{
243	if (off & cache_line_mask())
244		return;
245
246	if (pref_bias_clear_store) {
247		_uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
248			    A0);
249	} else if (cache_line_size == (half_clear_loop_size << 1)) {
250		if (cpu_has_cache_cdex_s) {
251			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
252		} else if (cpu_has_cache_cdex_p) {
253			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 
254				uasm_i_nop(buf);
255				uasm_i_nop(buf);
256				uasm_i_nop(buf);
257				uasm_i_nop(buf);
258			}
259
260			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 
261				uasm_i_lw(buf, ZERO, ZERO, AT);
262
263			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
264		}
265	}
266}
267
268extern u32 __clear_page_start;
269extern u32 __clear_page_end;
270extern u32 __copy_page_start;
271extern u32 __copy_page_end;
272
273void build_clear_page(void)
274{
275	int off;
276	u32 *buf = &__clear_page_start;
277	struct uasm_label *l = labels;
278	struct uasm_reloc *r = relocs;
279	int i;
280	static atomic_t run_once = ATOMIC_INIT(0);
281
282	if (atomic_xchg(&run_once, 1)) {
283		return;
284	}
285
286	memset(labels, 0, sizeof(labels));
287	memset(relocs, 0, sizeof(relocs));
288
289	set_prefetch_parameters();
290
291	/*
292	 * This algorithm makes the following assumptions:
293	 *   - The prefetch bias is a multiple of 2 words.
294	 *   - The prefetch bias is less than one page.
295	 */
296	BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
297	BUG_ON(PAGE_SIZE < pref_bias_clear_store);
298
299	off = PAGE_SIZE - pref_bias_clear_store;
300	if (off > 0xffff || !pref_bias_clear_store)
301		pg_addiu(&buf, A2, A0, off);
302	else
303		uasm_i_ori(&buf, A2, A0, off);
304
305	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
306		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
307
308	off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
309				* cache_line_size : 0;
310	while (off) {
311		build_clear_pref(&buf, -off);
312		off -= cache_line_size;
313	}
314	uasm_l_clear_pref(&l, buf);
315	do {
316		build_clear_pref(&buf, off);
317		build_clear_store(&buf, off);
318		off += clear_word_size;
319	} while (off < half_clear_loop_size);
320	pg_addiu(&buf, A0, A0, 2 * off);
321	off = -off;
322	do {
323		build_clear_pref(&buf, off);
324		if (off == -clear_word_size)
325			uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
326		build_clear_store(&buf, off);
327		off += clear_word_size;
328	} while (off < 0);
329
330	if (pref_bias_clear_store) {
331		pg_addiu(&buf, A2, A0, pref_bias_clear_store);
332		uasm_l_clear_nopref(&l, buf);
333		off = 0;
334		do {
335			build_clear_store(&buf, off);
336			off += clear_word_size;
337		} while (off < half_clear_loop_size);
338		pg_addiu(&buf, A0, A0, 2 * off);
339		off = -off;
340		do {
341			if (off == -clear_word_size)
342				uasm_il_bne(&buf, &r, A0, A2,
343					    label_clear_nopref);
344			build_clear_store(&buf, off);
345			off += clear_word_size;
346		} while (off < 0);
347	}
348
349	uasm_i_jr(&buf, RA);
350	uasm_i_nop(&buf);
351
352	BUG_ON(buf > &__clear_page_end);
353
354	uasm_resolve_relocs(relocs, labels);
355
356	pr_debug("Synthesized clear page handler (%u instructions).\n",
357		 (u32)(buf - &__clear_page_start));
358
359	pr_debug("\t.set push\n");
360	pr_debug("\t.set noreorder\n");
361	for (i = 0; i < (buf - &__clear_page_start); i++)
362		pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
363	pr_debug("\t.set pop\n");
364}
365
366static void build_copy_load(u32 **buf, int reg, int off)
367{
368	if (cpu_has_64bit_gp_regs) {
369		uasm_i_ld(buf, reg, off, A1);
370	} else {
371		uasm_i_lw(buf, reg, off, A1);
372	}
373}
374
375static void build_copy_store(u32 **buf, int reg, int off)
376{
377	if (cpu_has_64bit_gp_regs) {
378		uasm_i_sd(buf, reg, off, A0);
379	} else {
380		uasm_i_sw(buf, reg, off, A0);
381	}
382}
383
384static inline void build_copy_load_pref(u32 **buf, int off)
385{
386	if (off & cache_line_mask())
387		return;
388
389	if (pref_bias_copy_load)
390		_uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
391}
392
393static inline void build_copy_store_pref(u32 **buf, int off)
394{
395	if (off & cache_line_mask())
396		return;
397
398	if (pref_bias_copy_store) {
399		_uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
400			    A0);
401	} else if (cache_line_size == (half_copy_loop_size << 1)) {
402		if (cpu_has_cache_cdex_s) {
403			uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
404		} else if (cpu_has_cache_cdex_p) {
405			if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 
406				uasm_i_nop(buf);
407				uasm_i_nop(buf);
408				uasm_i_nop(buf);
409				uasm_i_nop(buf);
410			}
411
412			if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 
413				uasm_i_lw(buf, ZERO, ZERO, AT);
414
415			uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
416		}
417	}
418}
419
420void build_copy_page(void)
421{
422	int off;
423	u32 *buf = &__copy_page_start;
424	struct uasm_label *l = labels;
425	struct uasm_reloc *r = relocs;
426	int i;
427	static atomic_t run_once = ATOMIC_INIT(0);
428
429	if (atomic_xchg(&run_once, 1)) {
430		return;
431	}
432
433	memset(labels, 0, sizeof(labels));
434	memset(relocs, 0, sizeof(relocs));
435
436	set_prefetch_parameters();
437
438	/*
439	 * This algorithm makes the following assumptions:
440	 *   - All prefetch biases are multiples of 8 words.
441	 *   - The prefetch biases are less than one page.
442	 *   - The store prefetch bias isn't greater than the load
443	 *     prefetch bias.
444	 */
445	BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
446	BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
447	BUG_ON(PAGE_SIZE < pref_bias_copy_load);
448	BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
449
450	off = PAGE_SIZE - pref_bias_copy_load;
451	if (off > 0xffff || !pref_bias_copy_load)
452		pg_addiu(&buf, A2, A0, off);
453	else
454		uasm_i_ori(&buf, A2, A0, off);
455
456	if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
457		uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
458
459	off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
460				cache_line_size : 0;
461	while (off) {
462		build_copy_load_pref(&buf, -off);
463		off -= cache_line_size;
464	}
465	off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
466				cache_line_size : 0;
467	while (off) {
468		build_copy_store_pref(&buf, -off);
469		off -= cache_line_size;
470	}
471	uasm_l_copy_pref_both(&l, buf);
472	do {
473		build_copy_load_pref(&buf, off);
474		build_copy_load(&buf, T0, off);
475		build_copy_load_pref(&buf, off + copy_word_size);
476		build_copy_load(&buf, T1, off + copy_word_size);
477		build_copy_load_pref(&buf, off + 2 * copy_word_size);
478		build_copy_load(&buf, T2, off + 2 * copy_word_size);
479		build_copy_load_pref(&buf, off + 3 * copy_word_size);
480		build_copy_load(&buf, T3, off + 3 * copy_word_size);
481		build_copy_store_pref(&buf, off);
482		build_copy_store(&buf, T0, off);
483		build_copy_store_pref(&buf, off + copy_word_size);
484		build_copy_store(&buf, T1, off + copy_word_size);
485		build_copy_store_pref(&buf, off + 2 * copy_word_size);
486		build_copy_store(&buf, T2, off + 2 * copy_word_size);
487		build_copy_store_pref(&buf, off + 3 * copy_word_size);
488		build_copy_store(&buf, T3, off + 3 * copy_word_size);
489		off += 4 * copy_word_size;
490	} while (off < half_copy_loop_size);
491	pg_addiu(&buf, A1, A1, 2 * off);
492	pg_addiu(&buf, A0, A0, 2 * off);
493	off = -off;
494	do {
495		build_copy_load_pref(&buf, off);
496		build_copy_load(&buf, T0, off);
497		build_copy_load_pref(&buf, off + copy_word_size);
498		build_copy_load(&buf, T1, off + copy_word_size);
499		build_copy_load_pref(&buf, off + 2 * copy_word_size);
500		build_copy_load(&buf, T2, off + 2 * copy_word_size);
501		build_copy_load_pref(&buf, off + 3 * copy_word_size);
502		build_copy_load(&buf, T3, off + 3 * copy_word_size);
503		build_copy_store_pref(&buf, off);
504		build_copy_store(&buf, T0, off);
505		build_copy_store_pref(&buf, off + copy_word_size);
506		build_copy_store(&buf, T1, off + copy_word_size);
507		build_copy_store_pref(&buf, off + 2 * copy_word_size);
508		build_copy_store(&buf, T2, off + 2 * copy_word_size);
509		build_copy_store_pref(&buf, off + 3 * copy_word_size);
510		if (off == -(4 * copy_word_size))
511			uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
512		build_copy_store(&buf, T3, off + 3 * copy_word_size);
513		off += 4 * copy_word_size;
514	} while (off < 0);
515
516	if (pref_bias_copy_load - pref_bias_copy_store) {
517		pg_addiu(&buf, A2, A0,
518			 pref_bias_copy_load - pref_bias_copy_store);
519		uasm_l_copy_pref_store(&l, buf);
520		off = 0;
521		do {
522			build_copy_load(&buf, T0, off);
523			build_copy_load(&buf, T1, off + copy_word_size);
524			build_copy_load(&buf, T2, off + 2 * copy_word_size);
525			build_copy_load(&buf, T3, off + 3 * copy_word_size);
526			build_copy_store_pref(&buf, off);
527			build_copy_store(&buf, T0, off);
528			build_copy_store_pref(&buf, off + copy_word_size);
529			build_copy_store(&buf, T1, off + copy_word_size);
530			build_copy_store_pref(&buf, off + 2 * copy_word_size);
531			build_copy_store(&buf, T2, off + 2 * copy_word_size);
532			build_copy_store_pref(&buf, off + 3 * copy_word_size);
533			build_copy_store(&buf, T3, off + 3 * copy_word_size);
534			off += 4 * copy_word_size;
535		} while (off < half_copy_loop_size);
536		pg_addiu(&buf, A1, A1, 2 * off);
537		pg_addiu(&buf, A0, A0, 2 * off);
538		off = -off;
539		do {
540			build_copy_load(&buf, T0, off);
541			build_copy_load(&buf, T1, off + copy_word_size);
542			build_copy_load(&buf, T2, off + 2 * copy_word_size);
543			build_copy_load(&buf, T3, off + 3 * copy_word_size);
544			build_copy_store_pref(&buf, off);
545			build_copy_store(&buf, T0, off);
546			build_copy_store_pref(&buf, off + copy_word_size);
547			build_copy_store(&buf, T1, off + copy_word_size);
548			build_copy_store_pref(&buf, off + 2 * copy_word_size);
549			build_copy_store(&buf, T2, off + 2 * copy_word_size);
550			build_copy_store_pref(&buf, off + 3 * copy_word_size);
551			if (off == -(4 * copy_word_size))
552				uasm_il_bne(&buf, &r, A2, A0,
553					    label_copy_pref_store);
554			build_copy_store(&buf, T3, off + 3 * copy_word_size);
555			off += 4 * copy_word_size;
556		} while (off < 0);
557	}
558
559	if (pref_bias_copy_store) {
560		pg_addiu(&buf, A2, A0, pref_bias_copy_store);
561		uasm_l_copy_nopref(&l, buf);
562		off = 0;
563		do {
564			build_copy_load(&buf, T0, off);
565			build_copy_load(&buf, T1, off + copy_word_size);
566			build_copy_load(&buf, T2, off + 2 * copy_word_size);
567			build_copy_load(&buf, T3, off + 3 * copy_word_size);
568			build_copy_store(&buf, T0, off);
569			build_copy_store(&buf, T1, off + copy_word_size);
570			build_copy_store(&buf, T2, off + 2 * copy_word_size);
571			build_copy_store(&buf, T3, off + 3 * copy_word_size);
572			off += 4 * copy_word_size;
573		} while (off < half_copy_loop_size);
574		pg_addiu(&buf, A1, A1, 2 * off);
575		pg_addiu(&buf, A0, A0, 2 * off);
576		off = -off;
577		do {
578			build_copy_load(&buf, T0, off);
579			build_copy_load(&buf, T1, off + copy_word_size);
580			build_copy_load(&buf, T2, off + 2 * copy_word_size);
581			build_copy_load(&buf, T3, off + 3 * copy_word_size);
582			build_copy_store(&buf, T0, off);
583			build_copy_store(&buf, T1, off + copy_word_size);
584			build_copy_store(&buf, T2, off + 2 * copy_word_size);
585			if (off == -(4 * copy_word_size))
586				uasm_il_bne(&buf, &r, A2, A0,
587					    label_copy_nopref);
588			build_copy_store(&buf, T3, off + 3 * copy_word_size);
589			off += 4 * copy_word_size;
590		} while (off < 0);
591	}
592
593	uasm_i_jr(&buf, RA);
594	uasm_i_nop(&buf);
595
596	BUG_ON(buf > &__copy_page_end);
597
598	uasm_resolve_relocs(relocs, labels);
599
600	pr_debug("Synthesized copy page handler (%u instructions).\n",
601		 (u32)(buf - &__copy_page_start));
602
603	pr_debug("\t.set push\n");
604	pr_debug("\t.set noreorder\n");
605	for (i = 0; i < (buf - &__copy_page_start); i++)
606		pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
607	pr_debug("\t.set pop\n");
608}
609
610#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
611extern void clear_page_cpu(void *page);
612extern void copy_page_cpu(void *to, void *from);
613
614/*
615 * Pad descriptors to cacheline, since each is exclusively owned by a
616 * particular CPU.
617 */
618struct dmadscr {
619	u64 dscr_a;
620	u64 dscr_b;
621	u64 pad_a;
622	u64 pad_b;
623} ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
624
625void clear_page(void *page)
626{
627	u64 to_phys = CPHYSADDR((unsigned long)page);
628	unsigned int cpu = smp_processor_id();
629
630	/* if the page is not in KSEG0, use old way */
631	if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
632		return clear_page_cpu(page);
633
634	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
635				 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
636	page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
637	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
638
639	/*
640	 * Don't really want to do it this way, but there's no
641	 * reliable way to delay completion detection.
642	 */
643	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
644		 & M_DM_DSCR_BASE_INTERRUPT))
645		;
646	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
647}
648EXPORT_SYMBOL(clear_page);
649
650void copy_page(void *to, void *from)
651{
652	u64 from_phys = CPHYSADDR((unsigned long)from);
653	u64 to_phys = CPHYSADDR((unsigned long)to);
654	unsigned int cpu = smp_processor_id();
655
656	/* if any page is not in KSEG0, use old way */
657	if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
658	    || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
659		return copy_page_cpu(to, from);
660
661	page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
662				 M_DM_DSCRA_INTERRUPT;
663	page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
664	__raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
665
666	/*
667	 * Don't really want to do it this way, but there's no
668	 * reliable way to delay completion detection.
669	 */
670	while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
671		 & M_DM_DSCR_BASE_INTERRUPT))
672		;
673	__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
674}
675EXPORT_SYMBOL(copy_page);
676
677#endif /* CONFIG_SIBYTE_DMA_PAGEOPS */