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RT-AC66 3.0.0.4.374.130 core
[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / arch / mips / mm / pg-r4k.c
blob7e056e9488c6814081c9711985b695e9329737d1
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 */
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/mm.h>
12 #include <linux/module.h>
13 #include <linux/proc_fs.h>
14
15 #include <asm/cacheops.h>
16 #include <asm/inst.h>
17 #include <asm/io.h>
18 #include <asm/page.h>
19 #include <asm/pgtable.h>
20 #include <asm/prefetch.h>
21 #include <asm/system.h>
22 #include <asm/bootinfo.h>
23 #include <asm/mipsregs.h>
24 #include <asm/mmu_context.h>
25 #include <asm/cpu.h>
26 #include <asm/war.h>
27
28 #define half_scache_line_size() (cpu_scache_line_size() >> 1)
29 #define cpu_is_r4600_v1_x() ((read_c0_prid() & 0xfffffff0) == 0x00002010)
30 #define cpu_is_r4600_v2_x() ((read_c0_prid() & 0xfffffff0) == 0x00002020)
31
32
33 /*
34 * Maximum sizes:
35 *
36 * R4000 128 bytes S-cache: 0x58 bytes
37 * R4600 v1.7: 0x5c bytes
38 * R4600 v2.0: 0x60 bytes
39 * With prefetching, 16 byte strides 0xa0 bytes
40 */
41
42 static unsigned int clear_page_array[0x130 / 4];
43
44 void clear_page(void * page) __attribute__((alias("clear_page_array")));
45
46 EXPORT_SYMBOL(clear_page);
47
48 /*
49 * Maximum sizes:
50 *
51 * R4000 128 bytes S-cache: 0x11c bytes
52 * R4600 v1.7: 0x080 bytes
53 * R4600 v2.0: 0x07c bytes
54 * With prefetching, 16 byte strides 0x0b8 bytes
55 */
56 static unsigned int copy_page_array[0x148 / 4];
57
58 void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
59
60 EXPORT_SYMBOL(copy_page);
61
62 /*
63 * This is suboptimal for 32-bit kernels; we assume that R10000 is only used
64 * with 64-bit kernels. The prefetch offsets have been experimentally tuned
65 * an Origin 200.
66 */
67 static int pref_offset_clear __cpuinitdata = 512;
68 static int pref_offset_copy __cpuinitdata = 256;
69
70 static unsigned int pref_src_mode __cpuinitdata;
71 static unsigned int pref_dst_mode __cpuinitdata;
72
73 static int load_offset __cpuinitdata;
74 static int store_offset __cpuinitdata;
75
76 static unsigned int __cpuinitdata *dest, *epc;
77
78 static unsigned int instruction_pending;
79 static union mips_instruction delayed_mi;
80
81 static void __cpuinit emit_instruction(union mips_instruction mi)
82 {
83 if (instruction_pending)
84 *epc++ = delayed_mi.word;
85
86 instruction_pending = 1;
87 delayed_mi = mi;
88 }
89
90 static inline void flush_delay_slot_or_nop(void)
91 {
92 if (instruction_pending) {
93 *epc++ = delayed_mi.word;
94 instruction_pending = 0;
95 return;
96 }
97
98 *epc++ = 0;
99 }
100
101 static inline unsigned int *label(void)
102 {
103 if (instruction_pending) {
104 *epc++ = delayed_mi.word;
105 instruction_pending = 0;
106 }
107
108 return epc;
109 }
110
111 static inline void build_insn_word(unsigned int word)
112 {
113 union mips_instruction mi;
114
115 mi.word = word;
116
117 emit_instruction(mi);
118 }
119
120 static inline void build_nop(void)
121 {
122 build_insn_word(0); /* nop */
123 }
124
125 static inline void build_src_pref(int advance)
126 {
127 if (!(load_offset & (cpu_dcache_line_size() - 1)) && advance) {
128 union mips_instruction mi;
129
130 mi.i_format.opcode = pref_op;
131 mi.i_format.rs = 5; /* $a1 */
132 mi.i_format.rt = pref_src_mode;
133 mi.i_format.simmediate = load_offset + advance;
134
135 emit_instruction(mi);
136 }
137 }
138
139 static inline void __build_load_reg(int reg)
140 {
141 union mips_instruction mi;
142 unsigned int width;
143
144 if (cpu_has_64bit_gp_regs) {
145 mi.i_format.opcode = ld_op;
146 width = 8;
147 } else {
148 mi.i_format.opcode = lw_op;
149 width = 4;
150 }
151 mi.i_format.rs = 5; /* $a1 */
152 mi.i_format.rt = reg; /* $reg */
153 mi.i_format.simmediate = load_offset;
154
155 load_offset += width;
156 emit_instruction(mi);
157 }
158
159 static inline void build_load_reg(int reg)
160 {
161 if (cpu_has_prefetch)
162 build_src_pref(pref_offset_copy);
163
164 __build_load_reg(reg);
165 }
166
167 static inline void build_dst_pref(int advance)
168 {
169 if (!(store_offset & (cpu_dcache_line_size() - 1)) && advance) {
170 union mips_instruction mi;
171
172 mi.i_format.opcode = pref_op;
173 mi.i_format.rs = 4; /* $a0 */
174 mi.i_format.rt = pref_dst_mode;
175 mi.i_format.simmediate = store_offset + advance;
176
177 emit_instruction(mi);
178 }
179 }
180
181 static inline void build_cdex_s(void)
182 {
183 union mips_instruction mi;
184
185 if ((store_offset & (cpu_scache_line_size() - 1)))
186 return;
187
188 mi.c_format.opcode = cache_op;
189 mi.c_format.rs = 4; /* $a0 */
190 mi.c_format.c_op = 3; /* Create Dirty Exclusive */
191 mi.c_format.cache = 3; /* Secondary Data Cache */
192 mi.c_format.simmediate = store_offset;
193
194 emit_instruction(mi);
195 }
196
197 static inline void build_cdex_p(void)
198 {
199 union mips_instruction mi;
200
201 if (store_offset & (cpu_dcache_line_size() - 1))
202 return;
203
204 if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
205 build_nop();
206 build_nop();
207 build_nop();
208 build_nop();
209 }
210
211 if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
212 build_insn_word(0x8c200000); /* lw $zero, ($at) */
213
214 mi.c_format.opcode = cache_op;
215 mi.c_format.rs = 4; /* $a0 */
216 mi.c_format.c_op = 3; /* Create Dirty Exclusive */
217 mi.c_format.cache = 1; /* Data Cache */
218 mi.c_format.simmediate = store_offset;
219
220 emit_instruction(mi);
221 }
222
223 static void __cpuinit __build_store_reg(int reg)
224 {
225 union mips_instruction mi;
226 unsigned int width;
227
228 if (cpu_has_64bit_gp_regs ||
229 (cpu_has_64bit_zero_reg && reg == 0)) {
230 mi.i_format.opcode = sd_op;
231 width = 8;
232 } else {
233 mi.i_format.opcode = sw_op;
234 width = 4;
235 }
236 mi.i_format.rs = 4; /* $a0 */
237 mi.i_format.rt = reg; /* $reg */
238 mi.i_format.simmediate = store_offset;
239
240 store_offset += width;
241 emit_instruction(mi);
242 }
243
244 static inline void build_store_reg(int reg)
245 {
246 int pref_off = cpu_has_prefetch ?
247 (reg ? pref_offset_copy : pref_offset_clear) : 0;
248 if (pref_off)
249 build_dst_pref(pref_off);
250 else if (cpu_has_cache_cdex_s)
251 build_cdex_s();
252 else if (cpu_has_cache_cdex_p)
253 build_cdex_p();
254
255 __build_store_reg(reg);
256 }
257
258 static inline void build_addiu_a2_a0(unsigned long offset)
259 {
260 union mips_instruction mi;
261
262 BUG_ON(offset > 0x7fff);
263
264 mi.i_format.opcode = cpu_has_64bit_gp_regs ? daddiu_op : addiu_op;
265 mi.i_format.rs = 4; /* $a0 */
266 mi.i_format.rt = 6; /* $a2 */
267 mi.i_format.simmediate = offset;
268
269 emit_instruction(mi);
270 }
271
272 static inline void build_addiu_a2(unsigned long offset)
273 {
274 union mips_instruction mi;
275
276 BUG_ON(offset > 0x7fff);
277
278 mi.i_format.opcode = cpu_has_64bit_gp_regs ? daddiu_op : addiu_op;
279 mi.i_format.rs = 6; /* $a2 */
280 mi.i_format.rt = 6; /* $a2 */
281 mi.i_format.simmediate = offset;
282
283 emit_instruction(mi);
284 }
285
286 static inline void build_addiu_a1(unsigned long offset)
287 {
288 union mips_instruction mi;
289
290 BUG_ON(offset > 0x7fff);
291
292 mi.i_format.opcode = cpu_has_64bit_gp_regs ? daddiu_op : addiu_op;
293 mi.i_format.rs = 5; /* $a1 */
294 mi.i_format.rt = 5; /* $a1 */
295 mi.i_format.simmediate = offset;
296
297 load_offset -= offset;
298
299 emit_instruction(mi);
300 }
301
302 static inline void build_addiu_a0(unsigned long offset)
303 {
304 union mips_instruction mi;
305
306 BUG_ON(offset > 0x7fff);
307
308 mi.i_format.opcode = cpu_has_64bit_gp_regs ? daddiu_op : addiu_op;
309 mi.i_format.rs = 4; /* $a0 */
310 mi.i_format.rt = 4; /* $a0 */
311 mi.i_format.simmediate = offset;
312
313 store_offset -= offset;
314
315 emit_instruction(mi);
316 }
317
318 static inline void build_bne(unsigned int *dest)
319 {
320 union mips_instruction mi;
321
322 mi.i_format.opcode = bne_op;
323 mi.i_format.rs = 6; /* $a2 */
324 mi.i_format.rt = 4; /* $a0 */
325 mi.i_format.simmediate = dest - epc - 1;
326
327 *epc++ = mi.word;
328 flush_delay_slot_or_nop();
329 }
330
331 static inline void build_jr_ra(void)
332 {
333 union mips_instruction mi;
334
335 mi.r_format.opcode = spec_op;
336 mi.r_format.rs = 31;
337 mi.r_format.rt = 0;
338 mi.r_format.rd = 0;
339 mi.r_format.re = 0;
340 mi.r_format.func = jr_op;
341
342 *epc++ = mi.word;
343 flush_delay_slot_or_nop();
344 }
345
346 void __cpuinit build_clear_page(void)
347 {
348 unsigned int loop_start;
349 unsigned long off;
350
351 epc = (unsigned int *) &clear_page_array;
352 instruction_pending = 0;
353 store_offset = 0;
354
355 if (cpu_has_prefetch) {
356 switch (current_cpu_data.cputype) {
357 case CPU_TX49XX:
358 /* TX49 supports only Pref_Load */
359 pref_offset_clear = 0;
360 pref_offset_copy = 0;
361 break;
362
363 case CPU_RM9000:
364 /*
365 * As a workaround for erratum G105 which make the
366 * PrepareForStore hint unusable we fall back to
367 * StoreRetained on the RM9000. Once it is known which
368 * versions of the RM9000 we'll be able to condition-
369 * alize this.
370 */
371
372 case CPU_R10000:
373 case CPU_R12000:
374 case CPU_R14000:
375 pref_src_mode = Pref_LoadStreamed;
376 pref_dst_mode = Pref_StoreStreamed;
377 break;
378
379 default:
380 pref_src_mode = Pref_LoadStreamed;
381 pref_dst_mode = Pref_PrepareForStore;
382 break;
383 }
384 }
385
386 off = PAGE_SIZE - (cpu_has_prefetch ? pref_offset_clear : 0);
387 if (off > 0x7fff) {
388 build_addiu_a2_a0(off >> 1);
389 build_addiu_a2(off >> 1);
390 } else
391 build_addiu_a2_a0(off);
392
393 if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
394 build_insn_word(0x3c01a000); /* lui $at, 0xa000 */
395
396 dest = label();
397 do {
398 build_store_reg(0);
399 build_store_reg(0);
400 build_store_reg(0);
401 build_store_reg(0);
402 } while (store_offset < half_scache_line_size());
403 build_addiu_a0(2 * store_offset);
404 loop_start = store_offset;
405 do {
406 build_store_reg(0);
407 build_store_reg(0);
408 build_store_reg(0);
409 build_store_reg(0);
410 } while ((store_offset - loop_start) < half_scache_line_size());
411 build_bne(dest);
412
413 if (cpu_has_prefetch && pref_offset_clear) {
414 build_addiu_a2_a0(pref_offset_clear);
415 dest = label();
416 loop_start = store_offset;
417 do {
418 __build_store_reg(0);
419 __build_store_reg(0);
420 __build_store_reg(0);
421 __build_store_reg(0);
422 } while ((store_offset - loop_start) < half_scache_line_size());
423 build_addiu_a0(2 * store_offset);
424 loop_start = store_offset;
425 do {
426 __build_store_reg(0);
427 __build_store_reg(0);
428 __build_store_reg(0);
429 __build_store_reg(0);
430 } while ((store_offset - loop_start) < half_scache_line_size());
431 build_bne(dest);
432 }
433
434 build_jr_ra();
435
436 BUG_ON(epc > clear_page_array + ARRAY_SIZE(clear_page_array));
437 }
438
439 void __cpuinit build_copy_page(void)
440 {
441 unsigned int loop_start;
442 unsigned long off;
443
444 epc = (unsigned int *) &copy_page_array;
445 store_offset = load_offset = 0;
446 instruction_pending = 0;
447
448 off = PAGE_SIZE - (cpu_has_prefetch ? pref_offset_copy : 0);
449 if (off > 0x7fff) {
450 build_addiu_a2_a0(off >> 1);
451 build_addiu_a2(off >> 1);
452 } else
453 build_addiu_a2_a0(off);
454
455 if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
456 build_insn_word(0x3c01a000); /* lui $at, 0xa000 */
457
458 dest = label();
459 loop_start = store_offset;
460 do {
461 build_load_reg( 8);
462 build_load_reg( 9);
463 build_load_reg(10);
464 build_load_reg(11);
465 build_store_reg( 8);
466 build_store_reg( 9);
467 build_store_reg(10);
468 build_store_reg(11);
469 } while ((store_offset - loop_start) < half_scache_line_size());
470 build_addiu_a0(2 * store_offset);
471 build_addiu_a1(2 * load_offset);
472 loop_start = store_offset;
473 do {
474 build_load_reg( 8);
475 build_load_reg( 9);
476 build_load_reg(10);
477 build_load_reg(11);
478 build_store_reg( 8);
479 build_store_reg( 9);
480 build_store_reg(10);
481 build_store_reg(11);
482 } while ((store_offset - loop_start) < half_scache_line_size());
483 build_bne(dest);
484
485 if (cpu_has_prefetch && pref_offset_copy) {
486 build_addiu_a2_a0(pref_offset_copy);
487 dest = label();
488 loop_start = store_offset;
489 do {
490 __build_load_reg( 8);
491 __build_load_reg( 9);
492 __build_load_reg(10);
493 __build_load_reg(11);
494 __build_store_reg( 8);
495 __build_store_reg( 9);
496 __build_store_reg(10);
497 __build_store_reg(11);
498 } while ((store_offset - loop_start) < half_scache_line_size());
499 build_addiu_a0(2 * store_offset);
500 build_addiu_a1(2 * load_offset);
501 loop_start = store_offset;
502 do {
503 __build_load_reg( 8);
504 __build_load_reg( 9);
505 __build_load_reg(10);
506 __build_load_reg(11);
507 __build_store_reg( 8);
508 __build_store_reg( 9);
509 __build_store_reg(10);
510 __build_store_reg(11);
511 } while ((store_offset - loop_start) < half_scache_line_size());
512 build_bne(dest);
513 }
514
515 build_jr_ra();
516
517 BUG_ON(epc > copy_page_array + ARRAY_SIZE(copy_page_array));
518 }
Tomato firmware and modifications.