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MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / arch / mips / mm / tlbex.c
blobe06370f58ef3b5eee07d527ef8d653179dc60c25
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 * Synthesize TLB refill handlers at runtime.
7 *
8 * Copyright (C) 2004, 2005, 2006, 2008 Thiemo Seufer
9 * Copyright (C) 2005, 2007, 2008, 2009 Maciej W. Rozycki
10 * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
11 * Copyright (C) 2008, 2009 Cavium Networks, Inc.
12 *
13 * ... and the days got worse and worse and now you see
14 * I've gone completly out of my mind.
15 *
16 * They're coming to take me a away haha
17 * they're coming to take me a away hoho hihi haha
18 * to the funny farm where code is beautiful all the time ...
19 *
20 * (Condolences to Napoleon XIV)
21 */
22
23 #include <linux/bug.h>
24 #include <linux/kernel.h>
25 #include <linux/types.h>
26 #include <linux/smp.h>
27 #include <linux/string.h>
28 #include <linux/init.h>
29 #include <linux/cache.h>
30
31 #include <asm/cacheflush.h>
32 #include <asm/pgtable.h>
33 #include <asm/war.h>
34 #include <asm/uasm.h>
35
36 /*
37 * TLB load/store/modify handlers.
38 *
39 * Only the fastpath gets synthesized at runtime, the slowpath for
40 * do_page_fault remains normal asm.
41 */
42 extern void tlb_do_page_fault_0(void);
43 extern void tlb_do_page_fault_1(void);
44
45 struct work_registers {
46 int r1;
47 int r2;
48 int r3;
49 };
50
51 struct tlb_reg_save {
52 unsigned long a;
53 unsigned long b;
54 } ____cacheline_aligned_in_smp;
55
56 static struct tlb_reg_save handler_reg_save[NR_CPUS];
57
58 static inline int r45k_bvahwbug(void)
59 {
60 /* XXX: We should probe for the presence of this bug, but we don't. */
61 return 0;
62 }
63
64 static inline int r4k_250MHZhwbug(void)
65 {
66 /* XXX: We should probe for the presence of this bug, but we don't. */
67 return 0;
68 }
69
70 static inline int __maybe_unused bcm1250_m3_war(void)
71 {
72 return BCM1250_M3_WAR;
73 }
74
75 static inline int __maybe_unused r10000_llsc_war(void)
76 {
77 return R10000_LLSC_WAR;
78 }
79
80 static int use_bbit_insns(void)
81 {
82 switch (current_cpu_type()) {
83 case CPU_CAVIUM_OCTEON:
84 case CPU_CAVIUM_OCTEON_PLUS:
85 case CPU_CAVIUM_OCTEON2:
86 return 1;
87 default:
88 return 0;
89 }
90 }
91
92 static int use_lwx_insns(void)
93 {
94 switch (current_cpu_type()) {
95 case CPU_CAVIUM_OCTEON2:
96 return 1;
97 default:
98 return 0;
99 }
100 }
101 #if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \
102 CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
103 static bool scratchpad_available(void)
104 {
105 return true;
106 }
107 static int scratchpad_offset(int i)
108 {
109 /*
110 * CVMSEG starts at address -32768 and extends for
111 * CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines.
112 */
113 i += 1; /* Kernel use starts at the top and works down. */
114 return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768;
115 }
116 #else
117 static bool scratchpad_available(void)
118 {
119 return false;
120 }
121 static int scratchpad_offset(int i)
122 {
123 BUG();
124 /* Really unreachable, but evidently some GCC want this. */
125 return 0;
126 }
127 #endif
128 /*
129 * Found by experiment: At least some revisions of the 4kc throw under
130 * some circumstances a machine check exception, triggered by invalid
131 * values in the index register. Delaying the tlbp instruction until
132 * after the next branch, plus adding an additional nop in front of
133 * tlbwi/tlbwr avoids the invalid index register values. Nobody knows
134 * why; it's not an issue caused by the core RTL.
135 *
136 */
137 static int __cpuinit m4kc_tlbp_war(void)
138 {
139 return (current_cpu_data.processor_id & 0xffff00) ==
140 (PRID_COMP_MIPS | PRID_IMP_4KC);
141 }
142
143 /* Handle labels (which must be positive integers). */
144 enum label_id {
145 label_second_part = 1,
146 label_leave,
147 label_vmalloc,
148 label_vmalloc_done,
149 label_tlbw_hazard,
150 label_split,
151 label_tlbl_goaround1,
152 label_tlbl_goaround2,
153 label_nopage_tlbl,
154 label_nopage_tlbs,
155 label_nopage_tlbm,
156 label_smp_pgtable_change,
157 label_r3000_write_probe_fail,
158 label_large_segbits_fault,
159 #ifdef CONFIG_HUGETLB_PAGE
160 label_tlb_huge_update,
161 #endif
162 };
163
164 UASM_L_LA(_second_part)
165 UASM_L_LA(_leave)
166 UASM_L_LA(_vmalloc)
167 UASM_L_LA(_vmalloc_done)
168 UASM_L_LA(_tlbw_hazard)
169 UASM_L_LA(_split)
170 UASM_L_LA(_tlbl_goaround1)
171 UASM_L_LA(_tlbl_goaround2)
172 UASM_L_LA(_nopage_tlbl)
173 UASM_L_LA(_nopage_tlbs)
174 UASM_L_LA(_nopage_tlbm)
175 UASM_L_LA(_smp_pgtable_change)
176 UASM_L_LA(_r3000_write_probe_fail)
177 UASM_L_LA(_large_segbits_fault)
178 #ifdef CONFIG_HUGETLB_PAGE
179 UASM_L_LA(_tlb_huge_update)
180 #endif
181
182 /*
183 * For debug purposes.
184 */
185 static inline void dump_handler(const u32 *handler, int count)
186 {
187 int i;
188
189 pr_debug("\t.set push\n");
190 pr_debug("\t.set noreorder\n");
191
192 for (i = 0; i < count; i++)
193 pr_debug("\t%p\t.word 0x%08x\n", &handler[i], handler[i]);
194
195 pr_debug("\t.set pop\n");
196 }
197
198 /* The only general purpose registers allowed in TLB handlers. */
199 #define K0 26
200 #define K1 27
201
202 /* Some CP0 registers */
203 #define C0_INDEX 0, 0
204 #define C0_ENTRYLO0 2, 0
205 #define C0_TCBIND 2, 2
206 #define C0_ENTRYLO1 3, 0
207 #define C0_CONTEXT 4, 0
208 #define C0_PAGEMASK 5, 0
209 #define C0_BADVADDR 8, 0
210 #define C0_ENTRYHI 10, 0
211 #define C0_EPC 14, 0
212 #define C0_XCONTEXT 20, 0
213
214 #ifdef CONFIG_64BIT
215 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT)
216 #else
217 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT)
218 #endif
219
220 /* The worst case length of the handler is around 18 instructions for
221 * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
222 * Maximum space available is 32 instructions for R3000 and 64
223 * instructions for R4000.
224 *
225 * We deliberately chose a buffer size of 128, so we won't scribble
226 * over anything important on overflow before we panic.
227 */
228 static u32 tlb_handler[128] __cpuinitdata;
229
230 /* simply assume worst case size for labels and relocs */
231 static struct uasm_label labels[128] __cpuinitdata;
232 static struct uasm_reloc relocs[128] __cpuinitdata;
233
234 #ifdef CONFIG_64BIT
235 static int check_for_high_segbits __cpuinitdata;
236 #endif
237
238 static int check_for_high_segbits __cpuinitdata;
239
240 static unsigned int kscratch_used_mask __cpuinitdata;
241
242 static int __cpuinit allocate_kscratch(void)
243 {
244 int r;
245 unsigned int a = cpu_data[0].kscratch_mask & ~kscratch_used_mask;
246
247 r = ffs(a);
248
249 if (r == 0)
250 return -1;
251
252 r--; /* make it zero based */
253
254 kscratch_used_mask |= (1 << r);
255
256 return r;
257 }
258
259 static int scratch_reg __cpuinitdata;
260 static int pgd_reg __cpuinitdata;
261 enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch};
262
263 static struct work_registers __cpuinit build_get_work_registers(u32 **p)
264 {
265 struct work_registers r;
266
267 int smp_processor_id_reg;
268 int smp_processor_id_sel;
269 int smp_processor_id_shift;
270
271 if (scratch_reg > 0) {
272 /* Save in CPU local C0_KScratch? */
273 UASM_i_MTC0(p, 1, 31, scratch_reg);
274 r.r1 = K0;
275 r.r2 = K1;
276 r.r3 = 1;
277 return r;
278 }
279
280 if (num_possible_cpus() > 1) {
281 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
282 smp_processor_id_shift = 51;
283 smp_processor_id_reg = 20; /* XContext */
284 smp_processor_id_sel = 0;
285 #else
286 # ifdef CONFIG_32BIT
287 smp_processor_id_shift = 25;
288 smp_processor_id_reg = 4; /* Context */
289 smp_processor_id_sel = 0;
290 # endif
291 # ifdef CONFIG_64BIT
292 smp_processor_id_shift = 26;
293 smp_processor_id_reg = 4; /* Context */
294 smp_processor_id_sel = 0;
295 # endif
296 #endif
297 /* Get smp_processor_id */
298 UASM_i_MFC0(p, K0, smp_processor_id_reg, smp_processor_id_sel);
299 UASM_i_SRL_SAFE(p, K0, K0, smp_processor_id_shift);
300
301 /* handler_reg_save index in K0 */
302 UASM_i_SLL(p, K0, K0, ilog2(sizeof(struct tlb_reg_save)));
303
304 UASM_i_LA(p, K1, (long)&handler_reg_save);
305 UASM_i_ADDU(p, K0, K0, K1);
306 } else {
307 UASM_i_LA(p, K0, (long)&handler_reg_save);
308 }
309 /* K0 now points to save area, save $1 and $2 */
310 UASM_i_SW(p, 1, offsetof(struct tlb_reg_save, a), K0);
311 UASM_i_SW(p, 2, offsetof(struct tlb_reg_save, b), K0);
312
313 r.r1 = K1;
314 r.r2 = 1;
315 r.r3 = 2;
316 return r;
317 }
318
319 static void __cpuinit build_restore_work_registers(u32 **p)
320 {
321 if (scratch_reg > 0) {
322 UASM_i_MFC0(p, 1, 31, scratch_reg);
323 return;
324 }
325 /* K0 already points to save area, restore $1 and $2 */
326 UASM_i_LW(p, 1, offsetof(struct tlb_reg_save, a), K0);
327 UASM_i_LW(p, 2, offsetof(struct tlb_reg_save, b), K0);
328 }
329
330 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
331
332 /*
333 * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current,
334 * we cannot do r3000 under these circumstances.
335 *
336 * Declare pgd_current here instead of including mmu_context.h to avoid type
337 * conflicts for tlbmiss_handler_setup_pgd
338 */
339 extern unsigned long pgd_current[];
340
341 /*
342 * The R3000 TLB handler is simple.
343 */
344 static void __cpuinit build_r3000_tlb_refill_handler(void)
345 {
346 long pgdc = (long)pgd_current;
347 u32 *p;
348
349 memset(tlb_handler, 0, sizeof(tlb_handler));
350 p = tlb_handler;
351
352 uasm_i_mfc0(&p, K0, C0_BADVADDR);
353 uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */
354 uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1);
355 uasm_i_srl(&p, K0, K0, 22); /* load delay */
356 uasm_i_sll(&p, K0, K0, 2);
357 uasm_i_addu(&p, K1, K1, K0);
358 uasm_i_mfc0(&p, K0, C0_CONTEXT);
359 uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */
360 uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */
361 uasm_i_addu(&p, K1, K1, K0);
362 uasm_i_lw(&p, K0, 0, K1);
363 uasm_i_nop(&p); /* load delay */
364 uasm_i_mtc0(&p, K0, C0_ENTRYLO0);
365 uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
366 uasm_i_tlbwr(&p); /* cp0 delay */
367 uasm_i_jr(&p, K1);
368 uasm_i_rfe(&p); /* branch delay */
369
370 if (p > tlb_handler + 32)
371 panic("TLB refill handler space exceeded");
372
373 pr_debug("Wrote TLB refill handler (%u instructions).\n",
374 (unsigned int)(p - tlb_handler));
375
376 memcpy((void *)ebase, tlb_handler, 0x80);
377
378 dump_handler((u32 *)ebase, 32);
379 }
380 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
381
382 /*
383 * The R4000 TLB handler is much more complicated. We have two
384 * consecutive handler areas with 32 instructions space each.
385 * Since they aren't used at the same time, we can overflow in the
386 * other one.To keep things simple, we first assume linear space,
387 * then we relocate it to the final handler layout as needed.
388 */
389 static u32 final_handler[64] __cpuinitdata;
390
391 /*
392 * Hazards
393 *
394 * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
395 * 2. A timing hazard exists for the TLBP instruction.
396 *
397 * stalling_instruction
398 * TLBP
399 *
400 * The JTLB is being read for the TLBP throughout the stall generated by the
401 * previous instruction. This is not really correct as the stalling instruction
402 * can modify the address used to access the JTLB. The failure symptom is that
403 * the TLBP instruction will use an address created for the stalling instruction
404 * and not the address held in C0_ENHI and thus report the wrong results.
405 *
406 * The software work-around is to not allow the instruction preceding the TLBP
407 * to stall - make it an NOP or some other instruction guaranteed not to stall.
408 *
409 * Errata 2 will not be fixed. This errata is also on the R5000.
410 *
411 * As if we MIPS hackers wouldn't know how to nop pipelines happy ...
412 */
413 static void __cpuinit __maybe_unused build_tlb_probe_entry(u32 **p)
414 {
415 switch (current_cpu_type()) {
416 /* Found by experiment: R4600 v2.0/R4700 needs this, too. */
417 case CPU_R4600:
418 case CPU_R4700:
419 case CPU_R5000:
420 case CPU_R5000A:
421 case CPU_NEVADA:
422 uasm_i_nop(p);
423 uasm_i_tlbp(p);
424 break;
425
426 default:
427 uasm_i_tlbp(p);
428 break;
429 }
430 }
431
432 /*
433 * Write random or indexed TLB entry, and care about the hazards from
434 * the preceding mtc0 and for the following eret.
435 */
436 enum tlb_write_entry { tlb_random, tlb_indexed };
437
438 static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
439 struct uasm_reloc **r,
440 enum tlb_write_entry wmode)
441 {
442 void(*tlbw)(u32 **) = NULL;
443
444 switch (wmode) {
445 case tlb_random: tlbw = uasm_i_tlbwr; break;
446 case tlb_indexed: tlbw = uasm_i_tlbwi; break;
447 }
448
449 if (cpu_has_mips_r2) {
450 if (cpu_has_mips_r2_exec_hazard)
451 uasm_i_ehb(p);
452 tlbw(p);
453 return;
454 }
455
456 switch (current_cpu_type()) {
457 case CPU_R4000PC:
458 case CPU_R4000SC:
459 case CPU_R4000MC:
460 case CPU_R4400PC:
461 case CPU_R4400SC:
462 case CPU_R4400MC:
463 /*
464 * This branch uses up a mtc0 hazard nop slot and saves
465 * two nops after the tlbw instruction.
466 */
467 uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
468 tlbw(p);
469 uasm_l_tlbw_hazard(l, *p);
470 uasm_i_nop(p);
471 break;
472
473 case CPU_R4600:
474 case CPU_R4700:
475 case CPU_R5000:
476 case CPU_R5000A:
477 uasm_i_nop(p);
478 tlbw(p);
479 uasm_i_nop(p);
480 break;
481
482 case CPU_R4300:
483 case CPU_5KC:
484 case CPU_TX49XX:
485 case CPU_PR4450:
486 case CPU_XLR:
487 uasm_i_nop(p);
488 tlbw(p);
489 break;
490
491 case CPU_R10000:
492 case CPU_R12000:
493 case CPU_R14000:
494 case CPU_4KC:
495 case CPU_4KEC:
496 case CPU_SB1:
497 case CPU_SB1A:
498 case CPU_4KSC:
499 case CPU_20KC:
500 case CPU_25KF:
501 case CPU_BMIPS32:
502 case CPU_BMIPS3300:
503 case CPU_BMIPS4350:
504 case CPU_BMIPS4380:
505 case CPU_BMIPS5000:
506 case CPU_LOONGSON2:
507 case CPU_R5500:
508 if (m4kc_tlbp_war())
509 uasm_i_nop(p);
510 case CPU_ALCHEMY:
511 tlbw(p);
512 break;
513
514 case CPU_NEVADA:
515 uasm_i_nop(p); /* QED specifies 2 nops hazard */
516 /*
517 * This branch uses up a mtc0 hazard nop slot and saves
518 * a nop after the tlbw instruction.
519 */
520 uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
521 tlbw(p);
522 uasm_l_tlbw_hazard(l, *p);
523 break;
524
525 case CPU_RM7000:
526 uasm_i_nop(p);
527 uasm_i_nop(p);
528 uasm_i_nop(p);
529 uasm_i_nop(p);
530 tlbw(p);
531 break;
532
533 case CPU_RM9000:
534 /*
535 * When the JTLB is updated by tlbwi or tlbwr, a subsequent
536 * use of the JTLB for instructions should not occur for 4
537 * cpu cycles and use for data translations should not occur
538 * for 3 cpu cycles.
539 */
540 uasm_i_ssnop(p);
541 uasm_i_ssnop(p);
542 uasm_i_ssnop(p);
543 uasm_i_ssnop(p);
544 tlbw(p);
545 uasm_i_ssnop(p);
546 uasm_i_ssnop(p);
547 uasm_i_ssnop(p);
548 uasm_i_ssnop(p);
549 break;
550
551 case CPU_VR4111:
552 case CPU_VR4121:
553 case CPU_VR4122:
554 case CPU_VR4181:
555 case CPU_VR4181A:
556 uasm_i_nop(p);
557 uasm_i_nop(p);
558 tlbw(p);
559 uasm_i_nop(p);
560 uasm_i_nop(p);
561 break;
562
563 case CPU_VR4131:
564 case CPU_VR4133:
565 case CPU_R5432:
566 uasm_i_nop(p);
567 uasm_i_nop(p);
568 tlbw(p);
569 break;
570
571 case CPU_JZRISC:
572 tlbw(p);
573 uasm_i_nop(p);
574 break;
575
576 default:
577 panic("No TLB refill handler yet (CPU type: %d)",
578 current_cpu_data.cputype);
579 break;
580 }
581 }
582
583 static __cpuinit __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
584 unsigned int reg)
585 {
586 if (kernel_uses_smartmips_rixi) {
587 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_NO_EXEC));
588 UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
589 } else {
590 #ifdef CONFIG_64BIT_PHYS_ADDR
591 uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL));
592 #else
593 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL));
594 #endif
595 }
596 }
597
598 #ifdef CONFIG_HUGETLB_PAGE
599
600 static __cpuinit void build_restore_pagemask(u32 **p,
601 struct uasm_reloc **r,
602 unsigned int tmp,
603 enum label_id lid,
604 int restore_scratch)
605 {
606 if (restore_scratch) {
607 /* Reset default page size */
608 if (PM_DEFAULT_MASK >> 16) {
609 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
610 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
611 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
612 uasm_il_b(p, r, lid);
613 } else if (PM_DEFAULT_MASK) {
614 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
615 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
616 uasm_il_b(p, r, lid);
617 } else {
618 uasm_i_mtc0(p, 0, C0_PAGEMASK);
619 uasm_il_b(p, r, lid);
620 }
621 if (scratch_reg > 0)
622 UASM_i_MFC0(p, 1, 31, scratch_reg);
623 else
624 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
625 } else {
626 /* Reset default page size */
627 if (PM_DEFAULT_MASK >> 16) {
628 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
629 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
630 uasm_il_b(p, r, lid);
631 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
632 } else if (PM_DEFAULT_MASK) {
633 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
634 uasm_il_b(p, r, lid);
635 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
636 } else {
637 uasm_il_b(p, r, lid);
638 uasm_i_mtc0(p, 0, C0_PAGEMASK);
639 }
640 }
641 }
642
643 static __cpuinit void build_huge_tlb_write_entry(u32 **p,
644 struct uasm_label **l,
645 struct uasm_reloc **r,
646 unsigned int tmp,
647 enum tlb_write_entry wmode,
648 int restore_scratch)
649 {
650 /* Set huge page tlb entry size */
651 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
652 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
653 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
654
655 build_tlb_write_entry(p, l, r, wmode);
656
657 build_restore_pagemask(p, r, tmp, label_leave, restore_scratch);
658 }
659
660 /*
661 * Check if Huge PTE is present, if so then jump to LABEL.
662 */
663 static void __cpuinit
664 build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
665 unsigned int pmd, int lid)
666 {
667 UASM_i_LW(p, tmp, 0, pmd);
668 if (use_bbit_insns()) {
669 uasm_il_bbit1(p, r, tmp, ilog2(_PAGE_HUGE), lid);
670 } else {
671 uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
672 uasm_il_bnez(p, r, tmp, lid);
673 }
674 }
675
676 static __cpuinit void build_huge_update_entries(u32 **p,
677 unsigned int pte,
678 unsigned int tmp)
679 {
680 int small_sequence;
681
682 /*
683 * A huge PTE describes an area the size of the
684 * configured huge page size. This is twice the
685 * of the large TLB entry size we intend to use.
686 * A TLB entry half the size of the configured
687 * huge page size is configured into entrylo0
688 * and entrylo1 to cover the contiguous huge PTE
689 * address space.
690 */
691 small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
692
693 /* We can clobber tmp. It isn't used after this.*/
694 if (!small_sequence)
695 uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
696
697 build_convert_pte_to_entrylo(p, pte);
698 UASM_i_MTC0(p, pte, C0_ENTRYLO0); /* load it */
699 /* convert to entrylo1 */
700 if (small_sequence)
701 UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
702 else
703 UASM_i_ADDU(p, pte, pte, tmp);
704
705 UASM_i_MTC0(p, pte, C0_ENTRYLO1); /* load it */
706 }
707
708 static __cpuinit void build_huge_handler_tail(u32 **p,
709 struct uasm_reloc **r,
710 struct uasm_label **l,
711 unsigned int pte,
712 unsigned int ptr)
713 {
714 #ifdef CONFIG_SMP
715 UASM_i_SC(p, pte, 0, ptr);
716 uasm_il_beqz(p, r, pte, label_tlb_huge_update);
717 UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
718 #else
719 UASM_i_SW(p, pte, 0, ptr);
720 #endif
721 build_huge_update_entries(p, pte, ptr);
722 build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
723 }
724 #endif /* CONFIG_HUGETLB_PAGE */
725
726 #ifdef CONFIG_64BIT
727 /*
728 * TMP and PTR are scratch.
729 * TMP will be clobbered, PTR will hold the pmd entry.
730 */
731 static void __cpuinit
732 build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
733 unsigned int tmp, unsigned int ptr)
734 {
735 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
736 long pgdc = (long)pgd_current;
737 #endif
738 /*
739 * The vmalloc handling is not in the hotpath.
740 */
741 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
742
743 if (check_for_high_segbits) {
744 /*
745 * The kernel currently implicitely assumes that the
746 * MIPS SEGBITS parameter for the processor is
747 * (PGDIR_SHIFT+PGDIR_BITS) or less, and will never
748 * allocate virtual addresses outside the maximum
749 * range for SEGBITS = (PGDIR_SHIFT+PGDIR_BITS). But
750 * that doesn't prevent user code from accessing the
751 * higher xuseg addresses. Here, we make sure that
752 * everything but the lower xuseg addresses goes down
753 * the module_alloc/vmalloc path.
754 */
755 uasm_i_dsrl_safe(p, ptr, tmp, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
756 uasm_il_bnez(p, r, ptr, label_vmalloc);
757 } else {
758 uasm_il_bltz(p, r, tmp, label_vmalloc);
759 }
760 /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
761
762 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
763 if (pgd_reg != -1) {
764 /* pgd is in pgd_reg */
765 UASM_i_MFC0(p, ptr, 31, pgd_reg);
766 } else {
767 /*
768 * &pgd << 11 stored in CONTEXT [23..63].
769 */
770 UASM_i_MFC0(p, ptr, C0_CONTEXT);
771
772 /* Clear lower 23 bits of context. */
773 uasm_i_dins(p, ptr, 0, 0, 23);
774
775 /* 1 0 1 0 1 << 6 xkphys cached */
776 uasm_i_ori(p, ptr, ptr, 0x540);
777 uasm_i_drotr(p, ptr, ptr, 11);
778 }
779 #elif defined(CONFIG_SMP)
780 # ifdef CONFIG_MIPS_MT_SMTC
781 /*
782 * SMTC uses TCBind value as "CPU" index
783 */
784 uasm_i_mfc0(p, ptr, C0_TCBIND);
785 uasm_i_dsrl_safe(p, ptr, ptr, 19);
786 # else
787 /*
788 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
789 * stored in CONTEXT.
790 */
791 uasm_i_dmfc0(p, ptr, C0_CONTEXT);
792 uasm_i_dsrl_safe(p, ptr, ptr, 23);
793 # endif
794 UASM_i_LA_mostly(p, tmp, pgdc);
795 uasm_i_daddu(p, ptr, ptr, tmp);
796 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
797 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
798 #else
799 UASM_i_LA_mostly(p, ptr, pgdc);
800 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
801 #endif
802
803 uasm_l_vmalloc_done(l, *p);
804
805 /* get pgd offset in bytes */
806 uasm_i_dsrl_safe(p, tmp, tmp, PGDIR_SHIFT - 3);
807
808 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
809 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
810 #ifndef __PAGETABLE_PMD_FOLDED
811 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
812 uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
813 uasm_i_dsrl_safe(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
814 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
815 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
816 #endif
817 }
818
819 /*
820 * BVADDR is the faulting address, PTR is scratch.
821 * PTR will hold the pgd for vmalloc.
822 */
823 static void __cpuinit
824 build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
825 unsigned int bvaddr, unsigned int ptr,
826 enum vmalloc64_mode mode)
827 {
828 long swpd = (long)swapper_pg_dir;
829 int single_insn_swpd;
830 int did_vmalloc_branch = 0;
831
832 single_insn_swpd = uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd);
833
834 uasm_l_vmalloc(l, *p);
835
836 if (mode != not_refill && check_for_high_segbits) {
837 if (single_insn_swpd) {
838 uasm_il_bltz(p, r, bvaddr, label_vmalloc_done);
839 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
840 did_vmalloc_branch = 1;
841 /* fall through */
842 } else {
843 uasm_il_bgez(p, r, bvaddr, label_large_segbits_fault);
844 }
845 }
846 if (!did_vmalloc_branch) {
847 if (uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd)) {
848 uasm_il_b(p, r, label_vmalloc_done);
849 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
850 } else {
851 UASM_i_LA_mostly(p, ptr, swpd);
852 uasm_il_b(p, r, label_vmalloc_done);
853 if (uasm_in_compat_space_p(swpd))
854 uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
855 else
856 uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
857 }
858 }
859 if (mode != not_refill && check_for_high_segbits) {
860 uasm_l_large_segbits_fault(l, *p);
861 /*
862 * We get here if we are an xsseg address, or if we are
863 * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary.
864 *
865 * Ignoring xsseg (assume disabled so would generate
866 * (address errors?), the only remaining possibility
867 * is the upper xuseg addresses. On processors with
868 * TLB_SEGBITS <= PGDIR_SHIFT+PGDIR_BITS, these
869 * addresses would have taken an address error. We try
870 * to mimic that here by taking a load/istream page
871 * fault.
872 */
873 UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
874 uasm_i_jr(p, ptr);
875
876 if (mode == refill_scratch) {
877 if (scratch_reg > 0)
878 UASM_i_MFC0(p, 1, 31, scratch_reg);
879 else
880 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
881 } else {
882 uasm_i_nop(p);
883 }
884 }
885 }
886
887 #else /* !CONFIG_64BIT */
888
889 /*
890 * TMP and PTR are scratch.
891 * TMP will be clobbered, PTR will hold the pgd entry.
892 */
893 static void __cpuinit __maybe_unused
894 build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
895 {
896 long pgdc = (long)pgd_current;
897
898 /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
899 #ifdef CONFIG_SMP
900 #ifdef CONFIG_MIPS_MT_SMTC
901 /*
902 * SMTC uses TCBind value as "CPU" index
903 */
904 uasm_i_mfc0(p, ptr, C0_TCBIND);
905 UASM_i_LA_mostly(p, tmp, pgdc);
906 uasm_i_srl(p, ptr, ptr, 19);
907 #else
908 /*
909 * smp_processor_id() << 3 is stored in CONTEXT.
910 */
911 uasm_i_mfc0(p, ptr, C0_CONTEXT);
912 UASM_i_LA_mostly(p, tmp, pgdc);
913 uasm_i_srl(p, ptr, ptr, 23);
914 #endif
915 uasm_i_addu(p, ptr, tmp, ptr);
916 #else
917 UASM_i_LA_mostly(p, ptr, pgdc);
918 #endif
919 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
920 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
921 uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
922 uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
923 uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
924 }
925
926 #endif /* !CONFIG_64BIT */
927
928 static void __cpuinit build_adjust_context(u32 **p, unsigned int ctx)
929 {
930 unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
931 unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
932
933 switch (current_cpu_type()) {
934 case CPU_VR41XX:
935 case CPU_VR4111:
936 case CPU_VR4121:
937 case CPU_VR4122:
938 case CPU_VR4131:
939 case CPU_VR4181:
940 case CPU_VR4181A:
941 case CPU_VR4133:
942 shift += 2;
943 break;
944
945 default:
946 break;
947 }
948
949 if (shift)
950 UASM_i_SRL(p, ctx, ctx, shift);
951 uasm_i_andi(p, ctx, ctx, mask);
952 }
953
954 static void __cpuinit build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
955 {
956 /*
957 * Bug workaround for the Nevada. It seems as if under certain
958 * circumstances the move from cp0_context might produce a
959 * bogus result when the mfc0 instruction and its consumer are
960 * in a different cacheline or a load instruction, probably any
961 * memory reference, is between them.
962 */
963 switch (current_cpu_type()) {
964 case CPU_NEVADA:
965 UASM_i_LW(p, ptr, 0, ptr);
966 GET_CONTEXT(p, tmp); /* get context reg */
967 break;
968
969 default:
970 GET_CONTEXT(p, tmp); /* get context reg */
971 UASM_i_LW(p, ptr, 0, ptr);
972 break;
973 }
974
975 build_adjust_context(p, tmp);
976 UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
977 }
978
979 static void __cpuinit build_update_entries(u32 **p, unsigned int tmp,
980 unsigned int ptep)
981 {
982 /*
983 * 64bit address support (36bit on a 32bit CPU) in a 32bit
984 * Kernel is a special case. Only a few CPUs use it.
985 */
986 #ifdef CONFIG_64BIT_PHYS_ADDR
987 if (cpu_has_64bits) {
988 uasm_i_ld(p, tmp, 0, ptep); /* get even pte */
989 uasm_i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
990 if (kernel_uses_smartmips_rixi) {
991 UASM_i_SRL(p, tmp, tmp, ilog2(_PAGE_NO_EXEC));
992 UASM_i_SRL(p, ptep, ptep, ilog2(_PAGE_NO_EXEC));
993 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
994 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
995 UASM_i_ROTR(p, ptep, ptep, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
996 } else {
997 uasm_i_dsrl_safe(p, tmp, tmp, ilog2(_PAGE_GLOBAL)); /* convert to entrylo0 */
998 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
999 uasm_i_dsrl_safe(p, ptep, ptep, ilog2(_PAGE_GLOBAL)); /* convert to entrylo1 */
1000 }
1001 UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
1002 } else {
1003 int pte_off_even = sizeof(pte_t) / 2;
1004 int pte_off_odd = pte_off_even + sizeof(pte_t);
1005
1006 /* The pte entries are pre-shifted */
1007 uasm_i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
1008 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
1009 uasm_i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
1010 UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
1011 }
1012 #else
1013 UASM_i_LW(p, tmp, 0, ptep); /* get even pte */
1014 UASM_i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
1015 if (r45k_bvahwbug())
1016 build_tlb_probe_entry(p);
1017 if (kernel_uses_smartmips_rixi) {
1018 UASM_i_SRL(p, tmp, tmp, ilog2(_PAGE_NO_EXEC));
1019 UASM_i_SRL(p, ptep, ptep, ilog2(_PAGE_NO_EXEC));
1020 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
1021 if (r4k_250MHZhwbug())
1022 UASM_i_MTC0(p, 0, C0_ENTRYLO0);
1023 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
1024 UASM_i_ROTR(p, ptep, ptep, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
1025 } else {
1026 UASM_i_SRL(p, tmp, tmp, ilog2(_PAGE_GLOBAL)); /* convert to entrylo0 */
1027 if (r4k_250MHZhwbug())
1028 UASM_i_MTC0(p, 0, C0_ENTRYLO0);
1029 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
1030 UASM_i_SRL(p, ptep, ptep, ilog2(_PAGE_GLOBAL)); /* convert to entrylo1 */
1031 if (r45k_bvahwbug())
1032 uasm_i_mfc0(p, tmp, C0_INDEX);
1033 }
1034 if (r4k_250MHZhwbug())
1035 UASM_i_MTC0(p, 0, C0_ENTRYLO1);
1036 UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
1037 #endif
1038 }
1039
1040 struct mips_huge_tlb_info {
1041 int huge_pte;
1042 int restore_scratch;
1043 };
1044
1045 static struct mips_huge_tlb_info __cpuinit
1046 build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
1047 struct uasm_reloc **r, unsigned int tmp,
1048 unsigned int ptr, int c0_scratch)
1049 {
1050 struct mips_huge_tlb_info rv;
1051 unsigned int even, odd;
1052 int vmalloc_branch_delay_filled = 0;
1053 const int scratch = 1; /* Our extra working register */
1054
1055 rv.huge_pte = scratch;
1056 rv.restore_scratch = 0;
1057
1058 if (check_for_high_segbits) {
1059 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1060
1061 if (pgd_reg != -1)
1062 UASM_i_MFC0(p, ptr, 31, pgd_reg);
1063 else
1064 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1065
1066 if (c0_scratch >= 0)
1067 UASM_i_MTC0(p, scratch, 31, c0_scratch);
1068 else
1069 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1070
1071 uasm_i_dsrl_safe(p, scratch, tmp,
1072 PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
1073 uasm_il_bnez(p, r, scratch, label_vmalloc);
1074
1075 if (pgd_reg == -1) {
1076 vmalloc_branch_delay_filled = 1;
1077 /* Clear lower 23 bits of context. */
1078 uasm_i_dins(p, ptr, 0, 0, 23);
1079 }
1080 } else {
1081 if (pgd_reg != -1)
1082 UASM_i_MFC0(p, ptr, 31, pgd_reg);
1083 else
1084 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1085
1086 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1087
1088 if (c0_scratch >= 0)
1089 UASM_i_MTC0(p, scratch, 31, c0_scratch);
1090 else
1091 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1092
1093 if (pgd_reg == -1)
1094 /* Clear lower 23 bits of context. */
1095 uasm_i_dins(p, ptr, 0, 0, 23);
1096
1097 uasm_il_bltz(p, r, tmp, label_vmalloc);
1098 }
1099
1100 if (pgd_reg == -1) {
1101 vmalloc_branch_delay_filled = 1;
1102 /* 1 0 1 0 1 << 6 xkphys cached */
1103 uasm_i_ori(p, ptr, ptr, 0x540);
1104 uasm_i_drotr(p, ptr, ptr, 11);
1105 }
1106
1107 #ifdef __PAGETABLE_PMD_FOLDED
1108 #define LOC_PTEP scratch
1109 #else
1110 #define LOC_PTEP ptr
1111 #endif
1112
1113 if (!vmalloc_branch_delay_filled)
1114 /* get pgd offset in bytes */
1115 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1116
1117 uasm_l_vmalloc_done(l, *p);
1118
1119 /*
1120 * tmp ptr
1121 * fall-through case = badvaddr *pgd_current
1122 * vmalloc case = badvaddr swapper_pg_dir
1123 */
1124
1125 if (vmalloc_branch_delay_filled)
1126 /* get pgd offset in bytes */
1127 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1128
1129 #ifdef __PAGETABLE_PMD_FOLDED
1130 GET_CONTEXT(p, tmp); /* get context reg */
1131 #endif
1132 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3);
1133
1134 if (use_lwx_insns()) {
1135 UASM_i_LWX(p, LOC_PTEP, scratch, ptr);
1136 } else {
1137 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */
1138 uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */
1139 }
1140
1141 #ifndef __PAGETABLE_PMD_FOLDED
1142 /* get pmd offset in bytes */
1143 uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3);
1144 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3);
1145 GET_CONTEXT(p, tmp); /* get context reg */
1146
1147 if (use_lwx_insns()) {
1148 UASM_i_LWX(p, scratch, scratch, ptr);
1149 } else {
1150 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1151 UASM_i_LW(p, scratch, 0, ptr);
1152 }
1153 #endif
1154 /* Adjust the context during the load latency. */
1155 build_adjust_context(p, tmp);
1156
1157 #ifdef CONFIG_HUGETLB_PAGE
1158 uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update);
1159 /*
1160 * The in the LWX case we don't want to do the load in the
1161 * delay slot. It cannot issue in the same cycle and may be
1162 * speculative and unneeded.
1163 */
1164 if (use_lwx_insns())
1165 uasm_i_nop(p);
1166 #endif /* CONFIG_HUGETLB_PAGE */
1167
1168
1169 /* build_update_entries */
1170 if (use_lwx_insns()) {
1171 even = ptr;
1172 odd = tmp;
1173 UASM_i_LWX(p, even, scratch, tmp);
1174 UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t));
1175 UASM_i_LWX(p, odd, scratch, tmp);
1176 } else {
1177 UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */
1178 even = tmp;
1179 odd = ptr;
1180 UASM_i_LW(p, even, 0, ptr); /* get even pte */
1181 UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */
1182 }
1183 if (kernel_uses_smartmips_rixi) {
1184 uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_NO_EXEC));
1185 uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_NO_EXEC));
1186 uasm_i_drotr(p, even, even,
1187 ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
1188 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1189 uasm_i_drotr(p, odd, odd,
1190 ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
1191 } else {
1192 uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL));
1193 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1194 uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL));
1195 }
1196 UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
1197
1198 if (c0_scratch >= 0) {
1199 UASM_i_MFC0(p, scratch, 31, c0_scratch);
1200 build_tlb_write_entry(p, l, r, tlb_random);
1201 uasm_l_leave(l, *p);
1202 rv.restore_scratch = 1;
1203 } else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) {
1204 build_tlb_write_entry(p, l, r, tlb_random);
1205 uasm_l_leave(l, *p);
1206 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1207 } else {
1208 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1209 build_tlb_write_entry(p, l, r, tlb_random);
1210 uasm_l_leave(l, *p);
1211 rv.restore_scratch = 1;
1212 }
1213
1214 uasm_i_eret(p); /* return from trap */
1215
1216 return rv;
1217 }
1218
1219 /*
1220 * For a 64-bit kernel, we are using the 64-bit XTLB refill exception
1221 * because EXL == 0. If we wrap, we can also use the 32 instruction
1222 * slots before the XTLB refill exception handler which belong to the
1223 * unused TLB refill exception.
1224 */
1225 #define MIPS64_REFILL_INSNS 32
1226
1227 static void __cpuinit build_r4000_tlb_refill_handler(void)
1228 {
1229 u32 *p = tlb_handler;
1230 struct uasm_label *l = labels;
1231 struct uasm_reloc *r = relocs;
1232 u32 *f;
1233 unsigned int final_len;
1234 struct mips_huge_tlb_info htlb_info __maybe_unused;
1235 enum vmalloc64_mode vmalloc_mode __maybe_unused;
1236
1237 memset(tlb_handler, 0, sizeof(tlb_handler));
1238 memset(labels, 0, sizeof(labels));
1239 memset(relocs, 0, sizeof(relocs));
1240 memset(final_handler, 0, sizeof(final_handler));
1241
1242 if ((scratch_reg > 0 || scratchpad_available()) && use_bbit_insns()) {
1243 htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1,
1244 scratch_reg);
1245 vmalloc_mode = refill_scratch;
1246 } else {
1247 htlb_info.huge_pte = K0;
1248 htlb_info.restore_scratch = 0;
1249 vmalloc_mode = refill_noscratch;
1250 /*
1251 * create the plain linear handler
1252 */
1253 if (bcm1250_m3_war()) {
1254 unsigned int segbits = 44;
1255
1256 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1257 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
1258 uasm_i_xor(&p, K0, K0, K1);
1259 uasm_i_dsrl_safe(&p, K1, K0, 62);
1260 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
1261 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
1262 uasm_i_or(&p, K0, K0, K1);
1263 uasm_il_bnez(&p, &r, K0, label_leave);
1264 /* No need for uasm_i_nop */
1265 }
1266
1267 #ifdef CONFIG_64BIT
1268 build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
1269 #else
1270 build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
1271 #endif
1272
1273 #ifdef CONFIG_HUGETLB_PAGE
1274 build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
1275 #endif
1276
1277 build_get_ptep(&p, K0, K1);
1278 build_update_entries(&p, K0, K1);
1279 build_tlb_write_entry(&p, &l, &r, tlb_random);
1280 uasm_l_leave(&l, p);
1281 uasm_i_eret(&p); /* return from trap */
1282 }
1283 #ifdef CONFIG_HUGETLB_PAGE
1284 uasm_l_tlb_huge_update(&l, p);
1285 build_huge_update_entries(&p, htlb_info.huge_pte, K1);
1286 build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
1287 htlb_info.restore_scratch);
1288 #endif
1289
1290 #ifdef CONFIG_64BIT
1291 build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode);
1292 #endif
1293
1294 /*
1295 * Overflow check: For the 64bit handler, we need at least one
1296 * free instruction slot for the wrap-around branch. In worst
1297 * case, if the intended insertion point is a delay slot, we
1298 * need three, with the second nop'ed and the third being
1299 * unused.
1300 */
1301 /* Loongson2 ebase is different than r4k, we have more space */
1302 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
1303 if ((p - tlb_handler) > 64)
1304 panic("TLB refill handler space exceeded");
1305 #else
1306 if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
1307 || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
1308 && uasm_insn_has_bdelay(relocs,
1309 tlb_handler + MIPS64_REFILL_INSNS - 3)))
1310 panic("TLB refill handler space exceeded");
1311 #endif
1312
1313 /*
1314 * Now fold the handler in the TLB refill handler space.
1315 */
1316 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
1317 f = final_handler;
1318 /* Simplest case, just copy the handler. */
1319 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1320 final_len = p - tlb_handler;
1321 #else /* CONFIG_64BIT */
1322 f = final_handler + MIPS64_REFILL_INSNS;
1323 if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
1324 /* Just copy the handler. */
1325 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1326 final_len = p - tlb_handler;
1327 } else {
1328 #if defined(CONFIG_HUGETLB_PAGE)
1329 const enum label_id ls = label_tlb_huge_update;
1330 #else
1331 const enum label_id ls = label_vmalloc;
1332 #endif
1333 u32 *split;
1334 int ov = 0;
1335 int i;
1336
1337 for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
1338 ;
1339 BUG_ON(i == ARRAY_SIZE(labels));
1340 split = labels[i].addr;
1341
1342 /*
1343 * See if we have overflown one way or the other.
1344 */
1345 if (split > tlb_handler + MIPS64_REFILL_INSNS ||
1346 split < p - MIPS64_REFILL_INSNS)
1347 ov = 1;
1348
1349 if (ov) {
1350 /*
1351 * Split two instructions before the end. One
1352 * for the branch and one for the instruction
1353 * in the delay slot.
1354 */
1355 split = tlb_handler + MIPS64_REFILL_INSNS - 2;
1356
1357 /*
1358 * If the branch would fall in a delay slot,
1359 * we must back up an additional instruction
1360 * so that it is no longer in a delay slot.
1361 */
1362 if (uasm_insn_has_bdelay(relocs, split - 1))
1363 split--;
1364 }
1365 /* Copy first part of the handler. */
1366 uasm_copy_handler(relocs, labels, tlb_handler, split, f);
1367 f += split - tlb_handler;
1368
1369 if (ov) {
1370 /* Insert branch. */
1371 uasm_l_split(&l, final_handler);
1372 uasm_il_b(&f, &r, label_split);
1373 if (uasm_insn_has_bdelay(relocs, split))
1374 uasm_i_nop(&f);
1375 else {
1376 uasm_copy_handler(relocs, labels,
1377 split, split + 1, f);
1378 uasm_move_labels(labels, f, f + 1, -1);
1379 f++;
1380 split++;
1381 }
1382 }
1383
1384 /* Copy the rest of the handler. */
1385 uasm_copy_handler(relocs, labels, split, p, final_handler);
1386 final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
1387 (p - split);
1388 }
1389 #endif /* CONFIG_64BIT */
1390
1391 uasm_resolve_relocs(relocs, labels);
1392 pr_debug("Wrote TLB refill handler (%u instructions).\n",
1393 final_len);
1394
1395 memcpy((void *)ebase, final_handler, 0x100);
1396
1397 dump_handler((u32 *)ebase, 64);
1398 }
1399
1400 /*
1401 * 128 instructions for the fastpath handler is generous and should
1402 * never be exceeded.
1403 */
1404 #define FASTPATH_SIZE 128
1405
1406 u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned;
1407 u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned;
1408 u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned;
1409 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
1410 u32 tlbmiss_handler_setup_pgd[16] __cacheline_aligned;
1411
1412 static void __cpuinit build_r4000_setup_pgd(void)
1413 {
1414 const int a0 = 4;
1415 const int a1 = 5;
1416 u32 *p = tlbmiss_handler_setup_pgd;
1417 struct uasm_label *l = labels;
1418 struct uasm_reloc *r = relocs;
1419
1420 memset(tlbmiss_handler_setup_pgd, 0, sizeof(tlbmiss_handler_setup_pgd));
1421 memset(labels, 0, sizeof(labels));
1422 memset(relocs, 0, sizeof(relocs));
1423
1424 pgd_reg = allocate_kscratch();
1425
1426 if (pgd_reg == -1) {
1427 /* PGD << 11 in c0_Context */
1428 /*
1429 * If it is a ckseg0 address, convert to a physical
1430 * address. Shifting right by 29 and adding 4 will
1431 * result in zero for these addresses.
1432 *
1433 */
1434 UASM_i_SRA(&p, a1, a0, 29);
1435 UASM_i_ADDIU(&p, a1, a1, 4);
1436 uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1);
1437 uasm_i_nop(&p);
1438 uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
1439 uasm_l_tlbl_goaround1(&l, p);
1440 UASM_i_SLL(&p, a0, a0, 11);
1441 uasm_i_jr(&p, 31);
1442 UASM_i_MTC0(&p, a0, C0_CONTEXT);
1443 } else {
1444 /* PGD in c0_KScratch */
1445 uasm_i_jr(&p, 31);
1446 UASM_i_MTC0(&p, a0, 31, pgd_reg);
1447 }
1448 if (p - tlbmiss_handler_setup_pgd > ARRAY_SIZE(tlbmiss_handler_setup_pgd))
1449 panic("tlbmiss_handler_setup_pgd space exceeded");
1450 uasm_resolve_relocs(relocs, labels);
1451 pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n",
1452 (unsigned int)(p - tlbmiss_handler_setup_pgd));
1453
1454 dump_handler(tlbmiss_handler_setup_pgd,
1455 ARRAY_SIZE(tlbmiss_handler_setup_pgd));
1456 }
1457 #endif
1458
1459 static void __cpuinit
1460 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
1461 {
1462 #ifdef CONFIG_SMP
1463 # ifdef CONFIG_64BIT_PHYS_ADDR
1464 if (cpu_has_64bits)
1465 uasm_i_lld(p, pte, 0, ptr);
1466 else
1467 # endif
1468 UASM_i_LL(p, pte, 0, ptr);
1469 #else
1470 # ifdef CONFIG_64BIT_PHYS_ADDR
1471 if (cpu_has_64bits)
1472 uasm_i_ld(p, pte, 0, ptr);
1473 else
1474 # endif
1475 UASM_i_LW(p, pte, 0, ptr);
1476 #endif
1477 }
1478
1479 static void __cpuinit
1480 iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
1481 unsigned int mode)
1482 {
1483 #ifdef CONFIG_64BIT_PHYS_ADDR
1484 unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
1485 #endif
1486
1487 uasm_i_ori(p, pte, pte, mode);
1488 #ifdef CONFIG_SMP
1489 # ifdef CONFIG_64BIT_PHYS_ADDR
1490 if (cpu_has_64bits)
1491 uasm_i_scd(p, pte, 0, ptr);
1492 else
1493 # endif
1494 UASM_i_SC(p, pte, 0, ptr);
1495
1496 if (r10000_llsc_war())
1497 uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
1498 else
1499 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1500
1501 # ifdef CONFIG_64BIT_PHYS_ADDR
1502 if (!cpu_has_64bits) {
1503 /* no uasm_i_nop needed */
1504 uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
1505 uasm_i_ori(p, pte, pte, hwmode);
1506 uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
1507 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1508 /* no uasm_i_nop needed */
1509 uasm_i_lw(p, pte, 0, ptr);
1510 } else
1511 uasm_i_nop(p);
1512 # else
1513 uasm_i_nop(p);
1514 # endif
1515 #else
1516 # ifdef CONFIG_64BIT_PHYS_ADDR
1517 if (cpu_has_64bits)
1518 uasm_i_sd(p, pte, 0, ptr);
1519 else
1520 # endif
1521 UASM_i_SW(p, pte, 0, ptr);
1522
1523 # ifdef CONFIG_64BIT_PHYS_ADDR
1524 if (!cpu_has_64bits) {
1525 uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
1526 uasm_i_ori(p, pte, pte, hwmode);
1527 uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
1528 uasm_i_lw(p, pte, 0, ptr);
1529 }
1530 # endif
1531 #endif
1532 }
1533
1534 /*
1535 * Check if PTE is present, if not then jump to LABEL. PTR points to
1536 * the page table where this PTE is located, PTE will be re-loaded
1537 * with it's original value.
1538 */
1539 static void __cpuinit
1540 build_pte_present(u32 **p, struct uasm_reloc **r,
1541 int pte, int ptr, int scratch, enum label_id lid)
1542 {
1543 int t = scratch >= 0 ? scratch : pte;
1544
1545 if (kernel_uses_smartmips_rixi) {
1546 if (use_bbit_insns()) {
1547 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
1548 uasm_i_nop(p);
1549 } else {
1550 uasm_i_andi(p, t, pte, _PAGE_PRESENT);
1551 uasm_il_beqz(p, r, t, lid);
1552 if (pte == t)
1553 /* You lose the SMP race :-(*/
1554 iPTE_LW(p, pte, ptr);
1555 }
1556 } else {
1557 uasm_i_andi(p, t, pte, _PAGE_PRESENT | _PAGE_READ);
1558 uasm_i_xori(p, t, t, _PAGE_PRESENT | _PAGE_READ);
1559 uasm_il_bnez(p, r, t, lid);
1560 if (pte == t)
1561 /* You lose the SMP race :-(*/
1562 iPTE_LW(p, pte, ptr);
1563 }
1564 }
1565
1566 /* Make PTE valid, store result in PTR. */
1567 static void __cpuinit
1568 build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
1569 unsigned int ptr)
1570 {
1571 unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
1572
1573 iPTE_SW(p, r, pte, ptr, mode);
1574 }
1575
1576 /*
1577 * Check if PTE can be written to, if not branch to LABEL. Regardless
1578 * restore PTE with value from PTR when done.
1579 */
1580 static void __cpuinit
1581 build_pte_writable(u32 **p, struct uasm_reloc **r,
1582 unsigned int pte, unsigned int ptr, int scratch,
1583 enum label_id lid)
1584 {
1585 int t = scratch >= 0 ? scratch : pte;
1586
1587 uasm_i_andi(p, t, pte, _PAGE_PRESENT | _PAGE_WRITE);
1588 uasm_i_xori(p, t, t, _PAGE_PRESENT | _PAGE_WRITE);
1589 uasm_il_bnez(p, r, t, lid);
1590 if (pte == t)
1591 /* You lose the SMP race :-(*/
1592 iPTE_LW(p, pte, ptr);
1593 else
1594 uasm_i_nop(p);
1595 }
1596
1597 /* Make PTE writable, update software status bits as well, then store
1598 * at PTR.
1599 */
1600 static void __cpuinit
1601 build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
1602 unsigned int ptr)
1603 {
1604 unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1605 | _PAGE_DIRTY);
1606
1607 iPTE_SW(p, r, pte, ptr, mode);
1608 }
1609
1610 /*
1611 * Check if PTE can be modified, if not branch to LABEL. Regardless
1612 * restore PTE with value from PTR when done.
1613 */
1614 static void __cpuinit
1615 build_pte_modifiable(u32 **p, struct uasm_reloc **r,
1616 unsigned int pte, unsigned int ptr, int scratch,
1617 enum label_id lid)
1618 {
1619 if (use_bbit_insns()) {
1620 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_WRITE), lid);
1621 uasm_i_nop(p);
1622 } else {
1623 int t = scratch >= 0 ? scratch : pte;
1624 uasm_i_andi(p, t, pte, _PAGE_WRITE);
1625 uasm_il_beqz(p, r, t, lid);
1626 if (pte == t)
1627 /* You lose the SMP race :-(*/
1628 iPTE_LW(p, pte, ptr);
1629 }
1630 }
1631
1632 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1633
1634
1635 /*
1636 * R3000 style TLB load/store/modify handlers.
1637 */
1638
1639 /*
1640 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1641 * Then it returns.
1642 */
1643 static void __cpuinit
1644 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1645 {
1646 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1647 uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1648 uasm_i_tlbwi(p);
1649 uasm_i_jr(p, tmp);
1650 uasm_i_rfe(p); /* branch delay */
1651 }
1652
1653 /*
1654 * This places the pte into ENTRYLO0 and writes it with tlbwi
1655 * or tlbwr as appropriate. This is because the index register
1656 * may have the probe fail bit set as a result of a trap on a
1657 * kseg2 access, i.e. without refill. Then it returns.
1658 */
1659 static void __cpuinit
1660 build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
1661 struct uasm_reloc **r, unsigned int pte,
1662 unsigned int tmp)
1663 {
1664 uasm_i_mfc0(p, tmp, C0_INDEX);
1665 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1666 uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1667 uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
1668 uasm_i_tlbwi(p); /* cp0 delay */
1669 uasm_i_jr(p, tmp);
1670 uasm_i_rfe(p); /* branch delay */
1671 uasm_l_r3000_write_probe_fail(l, *p);
1672 uasm_i_tlbwr(p); /* cp0 delay */
1673 uasm_i_jr(p, tmp);
1674 uasm_i_rfe(p); /* branch delay */
1675 }
1676
1677 static void __cpuinit
1678 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1679 unsigned int ptr)
1680 {
1681 long pgdc = (long)pgd_current;
1682
1683 uasm_i_mfc0(p, pte, C0_BADVADDR);
1684 uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
1685 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
1686 uasm_i_srl(p, pte, pte, 22); /* load delay */
1687 uasm_i_sll(p, pte, pte, 2);
1688 uasm_i_addu(p, ptr, ptr, pte);
1689 uasm_i_mfc0(p, pte, C0_CONTEXT);
1690 uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
1691 uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
1692 uasm_i_addu(p, ptr, ptr, pte);
1693 uasm_i_lw(p, pte, 0, ptr);
1694 uasm_i_tlbp(p); /* load delay */
1695 }
1696
1697 static void __cpuinit build_r3000_tlb_load_handler(void)
1698 {
1699 u32 *p = handle_tlbl;
1700 struct uasm_label *l = labels;
1701 struct uasm_reloc *r = relocs;
1702
1703 memset(handle_tlbl, 0, sizeof(handle_tlbl));
1704 memset(labels, 0, sizeof(labels));
1705 memset(relocs, 0, sizeof(relocs));
1706
1707 build_r3000_tlbchange_handler_head(&p, K0, K1);
1708 build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl);
1709 uasm_i_nop(&p); /* load delay */
1710 build_make_valid(&p, &r, K0, K1);
1711 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1712
1713 uasm_l_nopage_tlbl(&l, p);
1714 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1715 uasm_i_nop(&p);
1716
1717 if ((p - handle_tlbl) > FASTPATH_SIZE)
1718 panic("TLB load handler fastpath space exceeded");
1719
1720 uasm_resolve_relocs(relocs, labels);
1721 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1722 (unsigned int)(p - handle_tlbl));
1723
1724 dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1725 }
1726
1727 static void __cpuinit build_r3000_tlb_store_handler(void)
1728 {
1729 u32 *p = handle_tlbs;
1730 struct uasm_label *l = labels;
1731 struct uasm_reloc *r = relocs;
1732
1733 memset(handle_tlbs, 0, sizeof(handle_tlbs));
1734 memset(labels, 0, sizeof(labels));
1735 memset(relocs, 0, sizeof(relocs));
1736
1737 build_r3000_tlbchange_handler_head(&p, K0, K1);
1738 build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs);
1739 uasm_i_nop(&p); /* load delay */
1740 build_make_write(&p, &r, K0, K1);
1741 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1742
1743 uasm_l_nopage_tlbs(&l, p);
1744 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1745 uasm_i_nop(&p);
1746
1747 if ((p - handle_tlbs) > FASTPATH_SIZE)
1748 panic("TLB store handler fastpath space exceeded");
1749
1750 uasm_resolve_relocs(relocs, labels);
1751 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1752 (unsigned int)(p - handle_tlbs));
1753
1754 dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1755 }
1756
1757 static void __cpuinit build_r3000_tlb_modify_handler(void)
1758 {
1759 u32 *p = handle_tlbm;
1760 struct uasm_label *l = labels;
1761 struct uasm_reloc *r = relocs;
1762
1763 memset(handle_tlbm, 0, sizeof(handle_tlbm));
1764 memset(labels, 0, sizeof(labels));
1765 memset(relocs, 0, sizeof(relocs));
1766
1767 build_r3000_tlbchange_handler_head(&p, K0, K1);
1768 build_pte_modifiable(&p, &r, K0, K1, -1, label_nopage_tlbm);
1769 uasm_i_nop(&p); /* load delay */
1770 build_make_write(&p, &r, K0, K1);
1771 build_r3000_pte_reload_tlbwi(&p, K0, K1);
1772
1773 uasm_l_nopage_tlbm(&l, p);
1774 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1775 uasm_i_nop(&p);
1776
1777 if ((p - handle_tlbm) > FASTPATH_SIZE)
1778 panic("TLB modify handler fastpath space exceeded");
1779
1780 uasm_resolve_relocs(relocs, labels);
1781 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1782 (unsigned int)(p - handle_tlbm));
1783
1784 dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1785 }
1786 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
1787
1788 /*
1789 * R4000 style TLB load/store/modify handlers.
1790 */
1791 static struct work_registers __cpuinit
1792 build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
1793 struct uasm_reloc **r)
1794 {
1795 struct work_registers wr = build_get_work_registers(p);
1796
1797 #ifdef CONFIG_64BIT
1798 build_get_pmde64(p, l, r, wr.r1, wr.r2); /* get pmd in ptr */
1799 #else
1800 build_get_pgde32(p, wr.r1, wr.r2); /* get pgd in ptr */
1801 #endif
1802
1803 #ifdef CONFIG_HUGETLB_PAGE
1804 /*
1805 * For huge tlb entries, pmd doesn't contain an address but
1806 * instead contains the tlb pte. Check the PAGE_HUGE bit and
1807 * see if we need to jump to huge tlb processing.
1808 */
1809 build_is_huge_pte(p, r, wr.r1, wr.r2, label_tlb_huge_update);
1810 #endif
1811
1812 UASM_i_MFC0(p, wr.r1, C0_BADVADDR);
1813 UASM_i_LW(p, wr.r2, 0, wr.r2);
1814 UASM_i_SRL(p, wr.r1, wr.r1, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
1815 uasm_i_andi(p, wr.r1, wr.r1, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
1816 UASM_i_ADDU(p, wr.r2, wr.r2, wr.r1);
1817
1818 #ifdef CONFIG_SMP
1819 uasm_l_smp_pgtable_change(l, *p);
1820 #endif
1821 iPTE_LW(p, wr.r1, wr.r2); /* get even pte */
1822 if (!m4kc_tlbp_war())
1823 build_tlb_probe_entry(p);
1824 return wr;
1825 }
1826
1827 static void __cpuinit
1828 build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
1829 struct uasm_reloc **r, unsigned int tmp,
1830 unsigned int ptr)
1831 {
1832 uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
1833 uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
1834 build_update_entries(p, tmp, ptr);
1835 build_tlb_write_entry(p, l, r, tlb_indexed);
1836 uasm_l_leave(l, *p);
1837 build_restore_work_registers(p);
1838 uasm_i_eret(p); /* return from trap */
1839
1840 #ifdef CONFIG_64BIT
1841 build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill);
1842 #endif
1843 }
1844
1845 static void __cpuinit build_r4000_tlb_load_handler(void)
1846 {
1847 u32 *p = handle_tlbl;
1848 struct uasm_label *l = labels;
1849 struct uasm_reloc *r = relocs;
1850 struct work_registers wr;
1851
1852 memset(handle_tlbl, 0, sizeof(handle_tlbl));
1853 memset(labels, 0, sizeof(labels));
1854 memset(relocs, 0, sizeof(relocs));
1855
1856 if (bcm1250_m3_war()) {
1857 unsigned int segbits = 44;
1858
1859 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1860 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
1861 uasm_i_xor(&p, K0, K0, K1);
1862 uasm_i_dsrl_safe(&p, K1, K0, 62);
1863 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
1864 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
1865 uasm_i_or(&p, K0, K0, K1);
1866 uasm_il_bnez(&p, &r, K0, label_leave);
1867 /* No need for uasm_i_nop */
1868 }
1869
1870 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
1871 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
1872 if (m4kc_tlbp_war())
1873 build_tlb_probe_entry(&p);
1874
1875 if (kernel_uses_smartmips_rixi) {
1876 /*
1877 * If the page is not _PAGE_VALID, RI or XI could not
1878 * have triggered it. Skip the expensive test..
1879 */
1880 if (use_bbit_insns()) {
1881 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
1882 label_tlbl_goaround1);
1883 } else {
1884 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
1885 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1);
1886 }
1887 uasm_i_nop(&p);
1888
1889 uasm_i_tlbr(&p);
1890 /* Examine entrylo 0 or 1 based on ptr. */
1891 if (use_bbit_insns()) {
1892 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
1893 } else {
1894 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
1895 uasm_i_beqz(&p, wr.r3, 8);
1896 }
1897 /* load it in the delay slot*/
1898 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
1899 /* load it if ptr is odd */
1900 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
1901 /*
1902 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
1903 * XI must have triggered it.
1904 */
1905 if (use_bbit_insns()) {
1906 uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl);
1907 uasm_i_nop(&p);
1908 uasm_l_tlbl_goaround1(&l, p);
1909 } else {
1910 uasm_i_andi(&p, wr.r3, wr.r3, 2);
1911 uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl);
1912 uasm_i_nop(&p);
1913 }
1914 uasm_l_tlbl_goaround1(&l, p);
1915 }
1916 build_make_valid(&p, &r, wr.r1, wr.r2);
1917 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
1918
1919 #ifdef CONFIG_HUGETLB_PAGE
1920 /*
1921 * This is the entry point when build_r4000_tlbchange_handler_head
1922 * spots a huge page.
1923 */
1924 uasm_l_tlb_huge_update(&l, p);
1925 iPTE_LW(&p, wr.r1, wr.r2);
1926 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
1927 build_tlb_probe_entry(&p);
1928
1929 if (kernel_uses_smartmips_rixi) {
1930 /*
1931 * If the page is not _PAGE_VALID, RI or XI could not
1932 * have triggered it. Skip the expensive test..
1933 */
1934 if (use_bbit_insns()) {
1935 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
1936 label_tlbl_goaround2);
1937 } else {
1938 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
1939 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
1940 }
1941 uasm_i_nop(&p);
1942
1943 uasm_i_tlbr(&p);
1944 /* Examine entrylo 0 or 1 based on ptr. */
1945 if (use_bbit_insns()) {
1946 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
1947 } else {
1948 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
1949 uasm_i_beqz(&p, wr.r3, 8);
1950 }
1951 /* load it in the delay slot*/
1952 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
1953 /* load it if ptr is odd */
1954 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
1955 /*
1956 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
1957 * XI must have triggered it.
1958 */
1959 if (use_bbit_insns()) {
1960 uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2);
1961 } else {
1962 uasm_i_andi(&p, wr.r3, wr.r3, 2);
1963 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
1964 }
1965 if (PM_DEFAULT_MASK == 0)
1966 uasm_i_nop(&p);
1967 /*
1968 * We clobbered C0_PAGEMASK, restore it. On the other branch
1969 * it is restored in build_huge_tlb_write_entry.
1970 */
1971 build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0);
1972
1973 uasm_l_tlbl_goaround2(&l, p);
1974 }
1975 uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID));
1976 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
1977 #endif
1978
1979 uasm_l_nopage_tlbl(&l, p);
1980 build_restore_work_registers(&p);
1981 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1982 uasm_i_nop(&p);
1983
1984 if ((p - handle_tlbl) > FASTPATH_SIZE)
1985 panic("TLB load handler fastpath space exceeded");
1986
1987 uasm_resolve_relocs(relocs, labels);
1988 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1989 (unsigned int)(p - handle_tlbl));
1990
1991 dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1992 }
1993
1994 static void __cpuinit build_r4000_tlb_store_handler(void)
1995 {
1996 u32 *p = handle_tlbs;
1997 struct uasm_label *l = labels;
1998 struct uasm_reloc *r = relocs;
1999 struct work_registers wr;
2000
2001 memset(handle_tlbs, 0, sizeof(handle_tlbs));
2002 memset(labels, 0, sizeof(labels));
2003 memset(relocs, 0, sizeof(relocs));
2004
2005 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2006 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2007 if (m4kc_tlbp_war())
2008 build_tlb_probe_entry(&p);
2009 build_make_write(&p, &r, wr.r1, wr.r2);
2010 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2011
2012 #ifdef CONFIG_HUGETLB_PAGE
2013 /*
2014 * This is the entry point when
2015 * build_r4000_tlbchange_handler_head spots a huge page.
2016 */
2017 uasm_l_tlb_huge_update(&l, p);
2018 iPTE_LW(&p, wr.r1, wr.r2);
2019 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2020 build_tlb_probe_entry(&p);
2021 uasm_i_ori(&p, wr.r1, wr.r1,
2022 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2023 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
2024 #endif
2025
2026 uasm_l_nopage_tlbs(&l, p);
2027 build_restore_work_registers(&p);
2028 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2029 uasm_i_nop(&p);
2030
2031 if ((p - handle_tlbs) > FASTPATH_SIZE)
2032 panic("TLB store handler fastpath space exceeded");
2033
2034 uasm_resolve_relocs(relocs, labels);
2035 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
2036 (unsigned int)(p - handle_tlbs));
2037
2038 dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
2039 }
2040
2041 static void __cpuinit build_r4000_tlb_modify_handler(void)
2042 {
2043 u32 *p = handle_tlbm;
2044 struct uasm_label *l = labels;
2045 struct uasm_reloc *r = relocs;
2046 struct work_registers wr;
2047
2048 memset(handle_tlbm, 0, sizeof(handle_tlbm));
2049 memset(labels, 0, sizeof(labels));
2050 memset(relocs, 0, sizeof(relocs));
2051
2052 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2053 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2054 if (m4kc_tlbp_war())
2055 build_tlb_probe_entry(&p);
2056 /* Present and writable bits set, set accessed and dirty bits. */
2057 build_make_write(&p, &r, wr.r1, wr.r2);
2058 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2059
2060 #ifdef CONFIG_HUGETLB_PAGE
2061 /*
2062 * This is the entry point when
2063 * build_r4000_tlbchange_handler_head spots a huge page.
2064 */
2065 uasm_l_tlb_huge_update(&l, p);
2066 iPTE_LW(&p, wr.r1, wr.r2);
2067 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2068 build_tlb_probe_entry(&p);
2069 uasm_i_ori(&p, wr.r1, wr.r1,
2070 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2071 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
2072 #endif
2073
2074 uasm_l_nopage_tlbm(&l, p);
2075 build_restore_work_registers(&p);
2076 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2077 uasm_i_nop(&p);
2078
2079 if ((p - handle_tlbm) > FASTPATH_SIZE)
2080 panic("TLB modify handler fastpath space exceeded");
2081
2082 uasm_resolve_relocs(relocs, labels);
2083 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
2084 (unsigned int)(p - handle_tlbm));
2085
2086 dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
2087 }
2088
2089 void __cpuinit build_tlb_refill_handler(void)
2090 {
2091 /*
2092 * The refill handler is generated per-CPU, multi-node systems
2093 * may have local storage for it. The other handlers are only
2094 * needed once.
2095 */
2096 static int run_once = 0;
2097
2098 #ifdef CONFIG_64BIT
2099 check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
2100 #endif
2101
2102 switch (current_cpu_type()) {
2103 case CPU_R2000:
2104 case CPU_R3000:
2105 case CPU_R3000A:
2106 case CPU_R3081E:
2107 case CPU_TX3912:
2108 case CPU_TX3922:
2109 case CPU_TX3927:
2110 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
2111 build_r3000_tlb_refill_handler();
2112 if (!run_once) {
2113 build_r3000_tlb_load_handler();
2114 build_r3000_tlb_store_handler();
2115 build_r3000_tlb_modify_handler();
2116 run_once++;
2117 }
2118 #else
2119 panic("No R3000 TLB refill handler");
2120 #endif
2121 break;
2122
2123 case CPU_R6000:
2124 case CPU_R6000A:
2125 panic("No R6000 TLB refill handler yet");
2126 break;
2127
2128 case CPU_R8000:
2129 panic("No R8000 TLB refill handler yet");
2130 break;
2131
2132 default:
2133 if (!run_once) {
2134 scratch_reg = allocate_kscratch();
2135 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
2136 build_r4000_setup_pgd();
2137 #endif
2138 build_r4000_tlb_load_handler();
2139 build_r4000_tlb_store_handler();
2140 build_r4000_tlb_modify_handler();
2141 run_once++;
2142 }
2143 build_r4000_tlb_refill_handler();
2144 }
2145 }
2146
2147 void __cpuinit flush_tlb_handlers(void)
2148 {
2149 local_flush_icache_range((unsigned long)handle_tlbl,
2150 (unsigned long)handle_tlbl + sizeof(handle_tlbl));
2151 local_flush_icache_range((unsigned long)handle_tlbs,
2152 (unsigned long)handle_tlbs + sizeof(handle_tlbs));
2153 local_flush_icache_range((unsigned long)handle_tlbm,
2154 (unsigned long)handle_tlbm + sizeof(handle_tlbm));
2155 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
2156 local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
2157 (unsigned long)tlbmiss_handler_setup_pgd + sizeof(handle_tlbm));
2158 #endif
2159 }
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