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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / arch / mips / mm / tlbex.c
blob79b9f2ad3ff514e0e48ab409d6465540a4fe097d
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 * Copyright (C) 2011 MIPS Technologies, Inc.
13 *
14 * ... and the days got worse and worse and now you see
15 * I've gone completely out of my mind.
16 *
17 * They're coming to take me a away haha
18 * they're coming to take me a away hoho hihi haha
19 * to the funny farm where code is beautiful all the time ...
20 *
21 * (Condolences to Napoleon XIV)
22 */
23
24 #include <linux/bug.h>
25 #include <linux/export.h>
26 #include <linux/kernel.h>
27 #include <linux/types.h>
28 #include <linux/smp.h>
29 #include <linux/string.h>
30 #include <linux/cache.h>
31
32 #include <asm/cacheflush.h>
33 #include <asm/cpu-type.h>
34 #include <asm/pgtable.h>
35 #include <asm/war.h>
36 #include <asm/uasm.h>
37 #include <asm/setup.h>
38 #include <asm/tlbex.h>
39
40 static int mips_xpa_disabled;
41
42 static int __init xpa_disable(char *s)
43 {
44 mips_xpa_disabled = 1;
45
46 return 1;
47 }
48
49 __setup("noxpa", xpa_disable);
50
51 /*
52 * TLB load/store/modify handlers.
53 *
54 * Only the fastpath gets synthesized at runtime, the slowpath for
55 * do_page_fault remains normal asm.
56 */
57 extern void tlb_do_page_fault_0(void);
58 extern void tlb_do_page_fault_1(void);
59
60 struct work_registers {
61 int r1;
62 int r2;
63 int r3;
64 };
65
66 struct tlb_reg_save {
67 unsigned long a;
68 unsigned long b;
69 } ____cacheline_aligned_in_smp;
70
71 static struct tlb_reg_save handler_reg_save[NR_CPUS];
72
73 static inline int r45k_bvahwbug(void)
74 {
75 /* XXX: We should probe for the presence of this bug, but we don't. */
76 return 0;
77 }
78
79 static inline int r4k_250MHZhwbug(void)
80 {
81 /* XXX: We should probe for the presence of this bug, but we don't. */
82 return 0;
83 }
84
85 static inline int __maybe_unused bcm1250_m3_war(void)
86 {
87 return BCM1250_M3_WAR;
88 }
89
90 static inline int __maybe_unused r10000_llsc_war(void)
91 {
92 return R10000_LLSC_WAR;
93 }
94
95 static int use_bbit_insns(void)
96 {
97 switch (current_cpu_type()) {
98 case CPU_CAVIUM_OCTEON:
99 case CPU_CAVIUM_OCTEON_PLUS:
100 case CPU_CAVIUM_OCTEON2:
101 case CPU_CAVIUM_OCTEON3:
102 return 1;
103 default:
104 return 0;
105 }
106 }
107
108 static int use_lwx_insns(void)
109 {
110 switch (current_cpu_type()) {
111 case CPU_CAVIUM_OCTEON2:
112 case CPU_CAVIUM_OCTEON3:
113 return 1;
114 default:
115 return 0;
116 }
117 }
118 #if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \
119 CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
120 static bool scratchpad_available(void)
121 {
122 return true;
123 }
124 static int scratchpad_offset(int i)
125 {
126 /*
127 * CVMSEG starts at address -32768 and extends for
128 * CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines.
129 */
130 i += 1; /* Kernel use starts at the top and works down. */
131 return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768;
132 }
133 #else
134 static bool scratchpad_available(void)
135 {
136 return false;
137 }
138 static int scratchpad_offset(int i)
139 {
140 BUG();
141 /* Really unreachable, but evidently some GCC want this. */
142 return 0;
143 }
144 #endif
145 /*
146 * Found by experiment: At least some revisions of the 4kc throw under
147 * some circumstances a machine check exception, triggered by invalid
148 * values in the index register. Delaying the tlbp instruction until
149 * after the next branch, plus adding an additional nop in front of
150 * tlbwi/tlbwr avoids the invalid index register values. Nobody knows
151 * why; it's not an issue caused by the core RTL.
152 *
153 */
154 static int m4kc_tlbp_war(void)
155 {
156 return current_cpu_type() == CPU_4KC;
157 }
158
159 /* Handle labels (which must be positive integers). */
160 enum label_id {
161 label_second_part = 1,
162 label_leave,
163 label_vmalloc,
164 label_vmalloc_done,
165 label_tlbw_hazard_0,
166 label_split = label_tlbw_hazard_0 + 8,
167 label_tlbl_goaround1,
168 label_tlbl_goaround2,
169 label_nopage_tlbl,
170 label_nopage_tlbs,
171 label_nopage_tlbm,
172 label_smp_pgtable_change,
173 label_r3000_write_probe_fail,
174 label_large_segbits_fault,
175 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
176 label_tlb_huge_update,
177 #endif
178 };
179
180 UASM_L_LA(_second_part)
181 UASM_L_LA(_leave)
182 UASM_L_LA(_vmalloc)
183 UASM_L_LA(_vmalloc_done)
184 /* _tlbw_hazard_x is handled differently. */
185 UASM_L_LA(_split)
186 UASM_L_LA(_tlbl_goaround1)
187 UASM_L_LA(_tlbl_goaround2)
188 UASM_L_LA(_nopage_tlbl)
189 UASM_L_LA(_nopage_tlbs)
190 UASM_L_LA(_nopage_tlbm)
191 UASM_L_LA(_smp_pgtable_change)
192 UASM_L_LA(_r3000_write_probe_fail)
193 UASM_L_LA(_large_segbits_fault)
194 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
195 UASM_L_LA(_tlb_huge_update)
196 #endif
197
198 static int hazard_instance;
199
200 static void uasm_bgezl_hazard(u32 **p, struct uasm_reloc **r, int instance)
201 {
202 switch (instance) {
203 case 0 ... 7:
204 uasm_il_bgezl(p, r, 0, label_tlbw_hazard_0 + instance);
205 return;
206 default:
207 BUG();
208 }
209 }
210
211 static void uasm_bgezl_label(struct uasm_label **l, u32 **p, int instance)
212 {
213 switch (instance) {
214 case 0 ... 7:
215 uasm_build_label(l, *p, label_tlbw_hazard_0 + instance);
216 break;
217 default:
218 BUG();
219 }
220 }
221
222 /*
223 * pgtable bits are assigned dynamically depending on processor feature
224 * and statically based on kernel configuration. This spits out the actual
225 * values the kernel is using. Required to make sense from disassembled
226 * TLB exception handlers.
227 */
228 static void output_pgtable_bits_defines(void)
229 {
230 #define pr_define(fmt, ...) \
231 pr_debug("#define " fmt, ##__VA_ARGS__)
232
233 pr_debug("#include <asm/asm.h>\n");
234 pr_debug("#include <asm/regdef.h>\n");
235 pr_debug("\n");
236
237 pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
238 pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
239 pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
240 pr_define("_PAGE_ACCESSED_SHIFT %d\n", _PAGE_ACCESSED_SHIFT);
241 pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);
242 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
243 pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
244 #endif
245 #ifdef _PAGE_NO_EXEC_SHIFT
246 if (cpu_has_rixi)
247 pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
248 #endif
249 pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
250 pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
251 pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
252 pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
253 pr_debug("\n");
254 }
255
256 static inline void dump_handler(const char *symbol, const u32 *handler, int count)
257 {
258 int i;
259
260 pr_debug("LEAF(%s)\n", symbol);
261
262 pr_debug("\t.set push\n");
263 pr_debug("\t.set noreorder\n");
264
265 for (i = 0; i < count; i++)
266 pr_debug("\t.word\t0x%08x\t\t# %p\n", handler[i], &handler[i]);
267
268 pr_debug("\t.set\tpop\n");
269
270 pr_debug("\tEND(%s)\n", symbol);
271 }
272
273 /* The only general purpose registers allowed in TLB handlers. */
274 #define K0 26
275 #define K1 27
276
277 /* Some CP0 registers */
278 #define C0_INDEX 0, 0
279 #define C0_ENTRYLO0 2, 0
280 #define C0_TCBIND 2, 2
281 #define C0_ENTRYLO1 3, 0
282 #define C0_CONTEXT 4, 0
283 #define C0_PAGEMASK 5, 0
284 #define C0_PWBASE 5, 5
285 #define C0_PWFIELD 5, 6
286 #define C0_PWSIZE 5, 7
287 #define C0_PWCTL 6, 6
288 #define C0_BADVADDR 8, 0
289 #define C0_PGD 9, 7
290 #define C0_ENTRYHI 10, 0
291 #define C0_EPC 14, 0
292 #define C0_XCONTEXT 20, 0
293
294 #ifdef CONFIG_64BIT
295 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT)
296 #else
297 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT)
298 #endif
299
300 /* The worst case length of the handler is around 18 instructions for
301 * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
302 * Maximum space available is 32 instructions for R3000 and 64
303 * instructions for R4000.
304 *
305 * We deliberately chose a buffer size of 128, so we won't scribble
306 * over anything important on overflow before we panic.
307 */
308 static u32 tlb_handler[128];
309
310 /* simply assume worst case size for labels and relocs */
311 static struct uasm_label labels[128];
312 static struct uasm_reloc relocs[128];
313
314 static int check_for_high_segbits;
315 static bool fill_includes_sw_bits;
316
317 static unsigned int kscratch_used_mask;
318
319 static inline int __maybe_unused c0_kscratch(void)
320 {
321 switch (current_cpu_type()) {
322 case CPU_XLP:
323 case CPU_XLR:
324 return 22;
325 default:
326 return 31;
327 }
328 }
329
330 static int allocate_kscratch(void)
331 {
332 int r;
333 unsigned int a = cpu_data[0].kscratch_mask & ~kscratch_used_mask;
334
335 r = ffs(a);
336
337 if (r == 0)
338 return -1;
339
340 r--; /* make it zero based */
341
342 kscratch_used_mask |= (1 << r);
343
344 return r;
345 }
346
347 static int scratch_reg;
348 int pgd_reg;
349 EXPORT_SYMBOL_GPL(pgd_reg);
350 enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch};
351
352 static struct work_registers build_get_work_registers(u32 **p)
353 {
354 struct work_registers r;
355
356 if (scratch_reg >= 0) {
357 /* Save in CPU local C0_KScratch? */
358 UASM_i_MTC0(p, 1, c0_kscratch(), scratch_reg);
359 r.r1 = K0;
360 r.r2 = K1;
361 r.r3 = 1;
362 return r;
363 }
364
365 if (num_possible_cpus() > 1) {
366 /* Get smp_processor_id */
367 UASM_i_CPUID_MFC0(p, K0, SMP_CPUID_REG);
368 UASM_i_SRL_SAFE(p, K0, K0, SMP_CPUID_REGSHIFT);
369
370 /* handler_reg_save index in K0 */
371 UASM_i_SLL(p, K0, K0, ilog2(sizeof(struct tlb_reg_save)));
372
373 UASM_i_LA(p, K1, (long)&handler_reg_save);
374 UASM_i_ADDU(p, K0, K0, K1);
375 } else {
376 UASM_i_LA(p, K0, (long)&handler_reg_save);
377 }
378 /* K0 now points to save area, save $1 and $2 */
379 UASM_i_SW(p, 1, offsetof(struct tlb_reg_save, a), K0);
380 UASM_i_SW(p, 2, offsetof(struct tlb_reg_save, b), K0);
381
382 r.r1 = K1;
383 r.r2 = 1;
384 r.r3 = 2;
385 return r;
386 }
387
388 static void build_restore_work_registers(u32 **p)
389 {
390 if (scratch_reg >= 0) {
391 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
392 return;
393 }
394 /* K0 already points to save area, restore $1 and $2 */
395 UASM_i_LW(p, 1, offsetof(struct tlb_reg_save, a), K0);
396 UASM_i_LW(p, 2, offsetof(struct tlb_reg_save, b), K0);
397 }
398
399 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
400
401 /*
402 * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current,
403 * we cannot do r3000 under these circumstances.
404 *
405 * Declare pgd_current here instead of including mmu_context.h to avoid type
406 * conflicts for tlbmiss_handler_setup_pgd
407 */
408 extern unsigned long pgd_current[];
409
410 /*
411 * The R3000 TLB handler is simple.
412 */
413 static void build_r3000_tlb_refill_handler(void)
414 {
415 long pgdc = (long)pgd_current;
416 u32 *p;
417
418 memset(tlb_handler, 0, sizeof(tlb_handler));
419 p = tlb_handler;
420
421 uasm_i_mfc0(&p, K0, C0_BADVADDR);
422 uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */
423 uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1);
424 uasm_i_srl(&p, K0, K0, 22); /* load delay */
425 uasm_i_sll(&p, K0, K0, 2);
426 uasm_i_addu(&p, K1, K1, K0);
427 uasm_i_mfc0(&p, K0, C0_CONTEXT);
428 uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */
429 uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */
430 uasm_i_addu(&p, K1, K1, K0);
431 uasm_i_lw(&p, K0, 0, K1);
432 uasm_i_nop(&p); /* load delay */
433 uasm_i_mtc0(&p, K0, C0_ENTRYLO0);
434 uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
435 uasm_i_tlbwr(&p); /* cp0 delay */
436 uasm_i_jr(&p, K1);
437 uasm_i_rfe(&p); /* branch delay */
438
439 if (p > tlb_handler + 32)
440 panic("TLB refill handler space exceeded");
441
442 pr_debug("Wrote TLB refill handler (%u instructions).\n",
443 (unsigned int)(p - tlb_handler));
444
445 memcpy((void *)ebase, tlb_handler, 0x80);
446 local_flush_icache_range(ebase, ebase + 0x80);
447
448 dump_handler("r3000_tlb_refill", (u32 *)ebase, 32);
449 }
450 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
451
452 /*
453 * The R4000 TLB handler is much more complicated. We have two
454 * consecutive handler areas with 32 instructions space each.
455 * Since they aren't used at the same time, we can overflow in the
456 * other one.To keep things simple, we first assume linear space,
457 * then we relocate it to the final handler layout as needed.
458 */
459 static u32 final_handler[64];
460
461 /*
462 * Hazards
463 *
464 * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
465 * 2. A timing hazard exists for the TLBP instruction.
466 *
467 * stalling_instruction
468 * TLBP
469 *
470 * The JTLB is being read for the TLBP throughout the stall generated by the
471 * previous instruction. This is not really correct as the stalling instruction
472 * can modify the address used to access the JTLB. The failure symptom is that
473 * the TLBP instruction will use an address created for the stalling instruction
474 * and not the address held in C0_ENHI and thus report the wrong results.
475 *
476 * The software work-around is to not allow the instruction preceding the TLBP
477 * to stall - make it an NOP or some other instruction guaranteed not to stall.
478 *
479 * Errata 2 will not be fixed. This errata is also on the R5000.
480 *
481 * As if we MIPS hackers wouldn't know how to nop pipelines happy ...
482 */
483 static void __maybe_unused build_tlb_probe_entry(u32 **p)
484 {
485 switch (current_cpu_type()) {
486 /* Found by experiment: R4600 v2.0/R4700 needs this, too. */
487 case CPU_R4600:
488 case CPU_R4700:
489 case CPU_R5000:
490 case CPU_NEVADA:
491 uasm_i_nop(p);
492 uasm_i_tlbp(p);
493 break;
494
495 default:
496 uasm_i_tlbp(p);
497 break;
498 }
499 }
500
501 void build_tlb_write_entry(u32 **p, struct uasm_label **l,
502 struct uasm_reloc **r,
503 enum tlb_write_entry wmode)
504 {
505 void(*tlbw)(u32 **) = NULL;
506
507 switch (wmode) {
508 case tlb_random: tlbw = uasm_i_tlbwr; break;
509 case tlb_indexed: tlbw = uasm_i_tlbwi; break;
510 }
511
512 if (cpu_has_mips_r2_r6) {
513 if (cpu_has_mips_r2_exec_hazard)
514 uasm_i_ehb(p);
515 tlbw(p);
516 return;
517 }
518
519 switch (current_cpu_type()) {
520 case CPU_R4000PC:
521 case CPU_R4000SC:
522 case CPU_R4000MC:
523 case CPU_R4400PC:
524 case CPU_R4400SC:
525 case CPU_R4400MC:
526 /*
527 * This branch uses up a mtc0 hazard nop slot and saves
528 * two nops after the tlbw instruction.
529 */
530 uasm_bgezl_hazard(p, r, hazard_instance);
531 tlbw(p);
532 uasm_bgezl_label(l, p, hazard_instance);
533 hazard_instance++;
534 uasm_i_nop(p);
535 break;
536
537 case CPU_R4600:
538 case CPU_R4700:
539 uasm_i_nop(p);
540 tlbw(p);
541 uasm_i_nop(p);
542 break;
543
544 case CPU_R5000:
545 case CPU_NEVADA:
546 uasm_i_nop(p); /* QED specifies 2 nops hazard */
547 uasm_i_nop(p); /* QED specifies 2 nops hazard */
548 tlbw(p);
549 break;
550
551 case CPU_R4300:
552 case CPU_5KC:
553 case CPU_TX49XX:
554 case CPU_PR4450:
555 case CPU_XLR:
556 uasm_i_nop(p);
557 tlbw(p);
558 break;
559
560 case CPU_R10000:
561 case CPU_R12000:
562 case CPU_R14000:
563 case CPU_R16000:
564 case CPU_4KC:
565 case CPU_4KEC:
566 case CPU_M14KC:
567 case CPU_M14KEC:
568 case CPU_SB1:
569 case CPU_SB1A:
570 case CPU_4KSC:
571 case CPU_20KC:
572 case CPU_25KF:
573 case CPU_BMIPS32:
574 case CPU_BMIPS3300:
575 case CPU_BMIPS4350:
576 case CPU_BMIPS4380:
577 case CPU_BMIPS5000:
578 case CPU_LOONGSON2:
579 case CPU_LOONGSON3:
580 case CPU_R5500:
581 if (m4kc_tlbp_war())
582 uasm_i_nop(p);
583 case CPU_ALCHEMY:
584 tlbw(p);
585 break;
586
587 case CPU_RM7000:
588 uasm_i_nop(p);
589 uasm_i_nop(p);
590 uasm_i_nop(p);
591 uasm_i_nop(p);
592 tlbw(p);
593 break;
594
595 case CPU_VR4111:
596 case CPU_VR4121:
597 case CPU_VR4122:
598 case CPU_VR4181:
599 case CPU_VR4181A:
600 uasm_i_nop(p);
601 uasm_i_nop(p);
602 tlbw(p);
603 uasm_i_nop(p);
604 uasm_i_nop(p);
605 break;
606
607 case CPU_VR4131:
608 case CPU_VR4133:
609 case CPU_R5432:
610 uasm_i_nop(p);
611 uasm_i_nop(p);
612 tlbw(p);
613 break;
614
615 case CPU_JZRISC:
616 tlbw(p);
617 uasm_i_nop(p);
618 break;
619
620 default:
621 panic("No TLB refill handler yet (CPU type: %d)",
622 current_cpu_type());
623 break;
624 }
625 }
626 EXPORT_SYMBOL_GPL(build_tlb_write_entry);
627
628 static __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
629 unsigned int reg)
630 {
631 if (_PAGE_GLOBAL_SHIFT == 0) {
632 /* pte_t is already in EntryLo format */
633 return;
634 }
635
636 if (cpu_has_rixi && _PAGE_NO_EXEC) {
637 if (fill_includes_sw_bits) {
638 UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
639 } else {
640 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_NO_EXEC));
641 UASM_i_ROTR(p, reg, reg,
642 ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
643 }
644 } else {
645 #ifdef CONFIG_PHYS_ADDR_T_64BIT
646 uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL));
647 #else
648 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL));
649 #endif
650 }
651 }
652
653 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
654
655 static void build_restore_pagemask(u32 **p, struct uasm_reloc **r,
656 unsigned int tmp, enum label_id lid,
657 int restore_scratch)
658 {
659 if (restore_scratch) {
660 /* Reset default page size */
661 if (PM_DEFAULT_MASK >> 16) {
662 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
663 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
664 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
665 uasm_il_b(p, r, lid);
666 } else if (PM_DEFAULT_MASK) {
667 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
668 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
669 uasm_il_b(p, r, lid);
670 } else {
671 uasm_i_mtc0(p, 0, C0_PAGEMASK);
672 uasm_il_b(p, r, lid);
673 }
674 if (scratch_reg >= 0)
675 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
676 else
677 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
678 } else {
679 /* Reset default page size */
680 if (PM_DEFAULT_MASK >> 16) {
681 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
682 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
683 uasm_il_b(p, r, lid);
684 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
685 } else if (PM_DEFAULT_MASK) {
686 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
687 uasm_il_b(p, r, lid);
688 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
689 } else {
690 uasm_il_b(p, r, lid);
691 uasm_i_mtc0(p, 0, C0_PAGEMASK);
692 }
693 }
694 }
695
696 static void build_huge_tlb_write_entry(u32 **p, struct uasm_label **l,
697 struct uasm_reloc **r,
698 unsigned int tmp,
699 enum tlb_write_entry wmode,
700 int restore_scratch)
701 {
702 /* Set huge page tlb entry size */
703 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
704 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
705 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
706
707 build_tlb_write_entry(p, l, r, wmode);
708
709 build_restore_pagemask(p, r, tmp, label_leave, restore_scratch);
710 }
711
712 /*
713 * Check if Huge PTE is present, if so then jump to LABEL.
714 */
715 static void
716 build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
717 unsigned int pmd, int lid)
718 {
719 UASM_i_LW(p, tmp, 0, pmd);
720 if (use_bbit_insns()) {
721 uasm_il_bbit1(p, r, tmp, ilog2(_PAGE_HUGE), lid);
722 } else {
723 uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
724 uasm_il_bnez(p, r, tmp, lid);
725 }
726 }
727
728 static void build_huge_update_entries(u32 **p, unsigned int pte,
729 unsigned int tmp)
730 {
731 int small_sequence;
732
733 /*
734 * A huge PTE describes an area the size of the
735 * configured huge page size. This is twice the
736 * of the large TLB entry size we intend to use.
737 * A TLB entry half the size of the configured
738 * huge page size is configured into entrylo0
739 * and entrylo1 to cover the contiguous huge PTE
740 * address space.
741 */
742 small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
743
744 /* We can clobber tmp. It isn't used after this.*/
745 if (!small_sequence)
746 uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
747
748 build_convert_pte_to_entrylo(p, pte);
749 UASM_i_MTC0(p, pte, C0_ENTRYLO0); /* load it */
750 /* convert to entrylo1 */
751 if (small_sequence)
752 UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
753 else
754 UASM_i_ADDU(p, pte, pte, tmp);
755
756 UASM_i_MTC0(p, pte, C0_ENTRYLO1); /* load it */
757 }
758
759 static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r,
760 struct uasm_label **l,
761 unsigned int pte,
762 unsigned int ptr,
763 unsigned int flush)
764 {
765 #ifdef CONFIG_SMP
766 UASM_i_SC(p, pte, 0, ptr);
767 uasm_il_beqz(p, r, pte, label_tlb_huge_update);
768 UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
769 #else
770 UASM_i_SW(p, pte, 0, ptr);
771 #endif
772 if (cpu_has_ftlb && flush) {
773 BUG_ON(!cpu_has_tlbinv);
774
775 UASM_i_MFC0(p, ptr, C0_ENTRYHI);
776 uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
777 UASM_i_MTC0(p, ptr, C0_ENTRYHI);
778 build_tlb_write_entry(p, l, r, tlb_indexed);
779
780 uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
781 UASM_i_MTC0(p, ptr, C0_ENTRYHI);
782 build_huge_update_entries(p, pte, ptr);
783 build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0);
784
785 return;
786 }
787
788 build_huge_update_entries(p, pte, ptr);
789 build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
790 }
791 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
792
793 #ifdef CONFIG_64BIT
794 /*
795 * TMP and PTR are scratch.
796 * TMP will be clobbered, PTR will hold the pmd entry.
797 */
798 void build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
799 unsigned int tmp, unsigned int ptr)
800 {
801 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
802 long pgdc = (long)pgd_current;
803 #endif
804 /*
805 * The vmalloc handling is not in the hotpath.
806 */
807 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
808
809 if (check_for_high_segbits) {
810 /*
811 * The kernel currently implicitely assumes that the
812 * MIPS SEGBITS parameter for the processor is
813 * (PGDIR_SHIFT+PGDIR_BITS) or less, and will never
814 * allocate virtual addresses outside the maximum
815 * range for SEGBITS = (PGDIR_SHIFT+PGDIR_BITS). But
816 * that doesn't prevent user code from accessing the
817 * higher xuseg addresses. Here, we make sure that
818 * everything but the lower xuseg addresses goes down
819 * the module_alloc/vmalloc path.
820 */
821 uasm_i_dsrl_safe(p, ptr, tmp, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
822 uasm_il_bnez(p, r, ptr, label_vmalloc);
823 } else {
824 uasm_il_bltz(p, r, tmp, label_vmalloc);
825 }
826 /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
827
828 if (pgd_reg != -1) {
829 /* pgd is in pgd_reg */
830 if (cpu_has_ldpte)
831 UASM_i_MFC0(p, ptr, C0_PWBASE);
832 else
833 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
834 } else {
835 #if defined(CONFIG_MIPS_PGD_C0_CONTEXT)
836 /*
837 * &pgd << 11 stored in CONTEXT [23..63].
838 */
839 UASM_i_MFC0(p, ptr, C0_CONTEXT);
840
841 /* Clear lower 23 bits of context. */
842 uasm_i_dins(p, ptr, 0, 0, 23);
843
844 /* 1 0 1 0 1 << 6 xkphys cached */
845 uasm_i_ori(p, ptr, ptr, 0x540);
846 uasm_i_drotr(p, ptr, ptr, 11);
847 #elif defined(CONFIG_SMP)
848 UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG);
849 uasm_i_dsrl_safe(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
850 UASM_i_LA_mostly(p, tmp, pgdc);
851 uasm_i_daddu(p, ptr, ptr, tmp);
852 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
853 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
854 #else
855 UASM_i_LA_mostly(p, ptr, pgdc);
856 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
857 #endif
858 }
859
860 uasm_l_vmalloc_done(l, *p);
861
862 /* get pgd offset in bytes */
863 uasm_i_dsrl_safe(p, tmp, tmp, PGDIR_SHIFT - 3);
864
865 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
866 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
867 #ifndef __PAGETABLE_PUD_FOLDED
868 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
869 uasm_i_ld(p, ptr, 0, ptr); /* get pud pointer */
870 uasm_i_dsrl_safe(p, tmp, tmp, PUD_SHIFT - 3); /* get pud offset in bytes */
871 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PUD - 1) << 3);
872 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pud offset */
873 #endif
874 #ifndef __PAGETABLE_PMD_FOLDED
875 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
876 uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
877 uasm_i_dsrl_safe(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
878 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
879 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
880 #endif
881 }
882 EXPORT_SYMBOL_GPL(build_get_pmde64);
883
884 /*
885 * BVADDR is the faulting address, PTR is scratch.
886 * PTR will hold the pgd for vmalloc.
887 */
888 static void
889 build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
890 unsigned int bvaddr, unsigned int ptr,
891 enum vmalloc64_mode mode)
892 {
893 long swpd = (long)swapper_pg_dir;
894 int single_insn_swpd;
895 int did_vmalloc_branch = 0;
896
897 single_insn_swpd = uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd);
898
899 uasm_l_vmalloc(l, *p);
900
901 if (mode != not_refill && check_for_high_segbits) {
902 if (single_insn_swpd) {
903 uasm_il_bltz(p, r, bvaddr, label_vmalloc_done);
904 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
905 did_vmalloc_branch = 1;
906 /* fall through */
907 } else {
908 uasm_il_bgez(p, r, bvaddr, label_large_segbits_fault);
909 }
910 }
911 if (!did_vmalloc_branch) {
912 if (single_insn_swpd) {
913 uasm_il_b(p, r, label_vmalloc_done);
914 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
915 } else {
916 UASM_i_LA_mostly(p, ptr, swpd);
917 uasm_il_b(p, r, label_vmalloc_done);
918 if (uasm_in_compat_space_p(swpd))
919 uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
920 else
921 uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
922 }
923 }
924 if (mode != not_refill && check_for_high_segbits) {
925 uasm_l_large_segbits_fault(l, *p);
926 /*
927 * We get here if we are an xsseg address, or if we are
928 * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary.
929 *
930 * Ignoring xsseg (assume disabled so would generate
931 * (address errors?), the only remaining possibility
932 * is the upper xuseg addresses. On processors with
933 * TLB_SEGBITS <= PGDIR_SHIFT+PGDIR_BITS, these
934 * addresses would have taken an address error. We try
935 * to mimic that here by taking a load/istream page
936 * fault.
937 */
938 UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
939 uasm_i_jr(p, ptr);
940
941 if (mode == refill_scratch) {
942 if (scratch_reg >= 0)
943 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
944 else
945 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
946 } else {
947 uasm_i_nop(p);
948 }
949 }
950 }
951
952 #else /* !CONFIG_64BIT */
953
954 /*
955 * TMP and PTR are scratch.
956 * TMP will be clobbered, PTR will hold the pgd entry.
957 */
958 void build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
959 {
960 if (pgd_reg != -1) {
961 /* pgd is in pgd_reg */
962 uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg);
963 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
964 } else {
965 long pgdc = (long)pgd_current;
966
967 /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
968 #ifdef CONFIG_SMP
969 uasm_i_mfc0(p, ptr, SMP_CPUID_REG);
970 UASM_i_LA_mostly(p, tmp, pgdc);
971 uasm_i_srl(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
972 uasm_i_addu(p, ptr, tmp, ptr);
973 #else
974 UASM_i_LA_mostly(p, ptr, pgdc);
975 #endif
976 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
977 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
978 }
979 uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
980 uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
981 uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
982 }
983 EXPORT_SYMBOL_GPL(build_get_pgde32);
984
985 #endif /* !CONFIG_64BIT */
986
987 static void build_adjust_context(u32 **p, unsigned int ctx)
988 {
989 unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
990 unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
991
992 switch (current_cpu_type()) {
993 case CPU_VR41XX:
994 case CPU_VR4111:
995 case CPU_VR4121:
996 case CPU_VR4122:
997 case CPU_VR4131:
998 case CPU_VR4181:
999 case CPU_VR4181A:
1000 case CPU_VR4133:
1001 shift += 2;
1002 break;
1003
1004 default:
1005 break;
1006 }
1007
1008 if (shift)
1009 UASM_i_SRL(p, ctx, ctx, shift);
1010 uasm_i_andi(p, ctx, ctx, mask);
1011 }
1012
1013 void build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
1014 {
1015 /*
1016 * Bug workaround for the Nevada. It seems as if under certain
1017 * circumstances the move from cp0_context might produce a
1018 * bogus result when the mfc0 instruction and its consumer are
1019 * in a different cacheline or a load instruction, probably any
1020 * memory reference, is between them.
1021 */
1022 switch (current_cpu_type()) {
1023 case CPU_NEVADA:
1024 UASM_i_LW(p, ptr, 0, ptr);
1025 GET_CONTEXT(p, tmp); /* get context reg */
1026 break;
1027
1028 default:
1029 GET_CONTEXT(p, tmp); /* get context reg */
1030 UASM_i_LW(p, ptr, 0, ptr);
1031 break;
1032 }
1033
1034 build_adjust_context(p, tmp);
1035 UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
1036 }
1037 EXPORT_SYMBOL_GPL(build_get_ptep);
1038
1039 void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
1040 {
1041 int pte_off_even = 0;
1042 int pte_off_odd = sizeof(pte_t);
1043
1044 #if defined(CONFIG_CPU_MIPS32) && defined(CONFIG_PHYS_ADDR_T_64BIT)
1045 /* The low 32 bits of EntryLo is stored in pte_high */
1046 pte_off_even += offsetof(pte_t, pte_high);
1047 pte_off_odd += offsetof(pte_t, pte_high);
1048 #endif
1049
1050 if (IS_ENABLED(CONFIG_XPA)) {
1051 uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */
1052 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
1053 UASM_i_MTC0(p, tmp, C0_ENTRYLO0);
1054
1055 if (cpu_has_xpa && !mips_xpa_disabled) {
1056 uasm_i_lw(p, tmp, 0, ptep);
1057 uasm_i_ext(p, tmp, tmp, 0, 24);
1058 uasm_i_mthc0(p, tmp, C0_ENTRYLO0);
1059 }
1060
1061 uasm_i_lw(p, tmp, pte_off_odd, ptep); /* odd pte */
1062 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
1063 UASM_i_MTC0(p, tmp, C0_ENTRYLO1);
1064
1065 if (cpu_has_xpa && !mips_xpa_disabled) {
1066 uasm_i_lw(p, tmp, sizeof(pte_t), ptep);
1067 uasm_i_ext(p, tmp, tmp, 0, 24);
1068 uasm_i_mthc0(p, tmp, C0_ENTRYLO1);
1069 }
1070 return;
1071 }
1072
1073 UASM_i_LW(p, tmp, pte_off_even, ptep); /* get even pte */
1074 UASM_i_LW(p, ptep, pte_off_odd, ptep); /* get odd pte */
1075 if (r45k_bvahwbug())
1076 build_tlb_probe_entry(p);
1077 build_convert_pte_to_entrylo(p, tmp);
1078 if (r4k_250MHZhwbug())
1079 UASM_i_MTC0(p, 0, C0_ENTRYLO0);
1080 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
1081 build_convert_pte_to_entrylo(p, ptep);
1082 if (r45k_bvahwbug())
1083 uasm_i_mfc0(p, tmp, C0_INDEX);
1084 if (r4k_250MHZhwbug())
1085 UASM_i_MTC0(p, 0, C0_ENTRYLO1);
1086 UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
1087 }
1088 EXPORT_SYMBOL_GPL(build_update_entries);
1089
1090 struct mips_huge_tlb_info {
1091 int huge_pte;
1092 int restore_scratch;
1093 bool need_reload_pte;
1094 };
1095
1096 static struct mips_huge_tlb_info
1097 build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
1098 struct uasm_reloc **r, unsigned int tmp,
1099 unsigned int ptr, int c0_scratch_reg)
1100 {
1101 struct mips_huge_tlb_info rv;
1102 unsigned int even, odd;
1103 int vmalloc_branch_delay_filled = 0;
1104 const int scratch = 1; /* Our extra working register */
1105
1106 rv.huge_pte = scratch;
1107 rv.restore_scratch = 0;
1108 rv.need_reload_pte = false;
1109
1110 if (check_for_high_segbits) {
1111 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1112
1113 if (pgd_reg != -1)
1114 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
1115 else
1116 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1117
1118 if (c0_scratch_reg >= 0)
1119 UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1120 else
1121 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1122
1123 uasm_i_dsrl_safe(p, scratch, tmp,
1124 PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
1125 uasm_il_bnez(p, r, scratch, label_vmalloc);
1126
1127 if (pgd_reg == -1) {
1128 vmalloc_branch_delay_filled = 1;
1129 /* Clear lower 23 bits of context. */
1130 uasm_i_dins(p, ptr, 0, 0, 23);
1131 }
1132 } else {
1133 if (pgd_reg != -1)
1134 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
1135 else
1136 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1137
1138 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1139
1140 if (c0_scratch_reg >= 0)
1141 UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1142 else
1143 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1144
1145 if (pgd_reg == -1)
1146 /* Clear lower 23 bits of context. */
1147 uasm_i_dins(p, ptr, 0, 0, 23);
1148
1149 uasm_il_bltz(p, r, tmp, label_vmalloc);
1150 }
1151
1152 if (pgd_reg == -1) {
1153 vmalloc_branch_delay_filled = 1;
1154 /* 1 0 1 0 1 << 6 xkphys cached */
1155 uasm_i_ori(p, ptr, ptr, 0x540);
1156 uasm_i_drotr(p, ptr, ptr, 11);
1157 }
1158
1159 #ifdef __PAGETABLE_PMD_FOLDED
1160 #define LOC_PTEP scratch
1161 #else
1162 #define LOC_PTEP ptr
1163 #endif
1164
1165 if (!vmalloc_branch_delay_filled)
1166 /* get pgd offset in bytes */
1167 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1168
1169 uasm_l_vmalloc_done(l, *p);
1170
1171 /*
1172 * tmp ptr
1173 * fall-through case = badvaddr *pgd_current
1174 * vmalloc case = badvaddr swapper_pg_dir
1175 */
1176
1177 if (vmalloc_branch_delay_filled)
1178 /* get pgd offset in bytes */
1179 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1180
1181 #ifdef __PAGETABLE_PMD_FOLDED
1182 GET_CONTEXT(p, tmp); /* get context reg */
1183 #endif
1184 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3);
1185
1186 if (use_lwx_insns()) {
1187 UASM_i_LWX(p, LOC_PTEP, scratch, ptr);
1188 } else {
1189 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */
1190 uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */
1191 }
1192
1193 #ifndef __PAGETABLE_PUD_FOLDED
1194 /* get pud offset in bytes */
1195 uasm_i_dsrl_safe(p, scratch, tmp, PUD_SHIFT - 3);
1196 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PUD - 1) << 3);
1197
1198 if (use_lwx_insns()) {
1199 UASM_i_LWX(p, ptr, scratch, ptr);
1200 } else {
1201 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1202 UASM_i_LW(p, ptr, 0, ptr);
1203 }
1204 /* ptr contains a pointer to PMD entry */
1205 /* tmp contains the address */
1206 #endif
1207
1208 #ifndef __PAGETABLE_PMD_FOLDED
1209 /* get pmd offset in bytes */
1210 uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3);
1211 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3);
1212 GET_CONTEXT(p, tmp); /* get context reg */
1213
1214 if (use_lwx_insns()) {
1215 UASM_i_LWX(p, scratch, scratch, ptr);
1216 } else {
1217 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1218 UASM_i_LW(p, scratch, 0, ptr);
1219 }
1220 #endif
1221 /* Adjust the context during the load latency. */
1222 build_adjust_context(p, tmp);
1223
1224 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1225 uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update);
1226 /*
1227 * The in the LWX case we don't want to do the load in the
1228 * delay slot. It cannot issue in the same cycle and may be
1229 * speculative and unneeded.
1230 */
1231 if (use_lwx_insns())
1232 uasm_i_nop(p);
1233 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
1234
1235
1236 /* build_update_entries */
1237 if (use_lwx_insns()) {
1238 even = ptr;
1239 odd = tmp;
1240 UASM_i_LWX(p, even, scratch, tmp);
1241 UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t));
1242 UASM_i_LWX(p, odd, scratch, tmp);
1243 } else {
1244 UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */
1245 even = tmp;
1246 odd = ptr;
1247 UASM_i_LW(p, even, 0, ptr); /* get even pte */
1248 UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */
1249 }
1250 if (cpu_has_rixi) {
1251 uasm_i_drotr(p, even, even, ilog2(_PAGE_GLOBAL));
1252 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1253 uasm_i_drotr(p, odd, odd, ilog2(_PAGE_GLOBAL));
1254 } else {
1255 uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL));
1256 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1257 uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL));
1258 }
1259 UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
1260
1261 if (c0_scratch_reg >= 0) {
1262 UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1263 build_tlb_write_entry(p, l, r, tlb_random);
1264 uasm_l_leave(l, *p);
1265 rv.restore_scratch = 1;
1266 } else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) {
1267 build_tlb_write_entry(p, l, r, tlb_random);
1268 uasm_l_leave(l, *p);
1269 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1270 } else {
1271 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1272 build_tlb_write_entry(p, l, r, tlb_random);
1273 uasm_l_leave(l, *p);
1274 rv.restore_scratch = 1;
1275 }
1276
1277 uasm_i_eret(p); /* return from trap */
1278
1279 return rv;
1280 }
1281
1282 /*
1283 * For a 64-bit kernel, we are using the 64-bit XTLB refill exception
1284 * because EXL == 0. If we wrap, we can also use the 32 instruction
1285 * slots before the XTLB refill exception handler which belong to the
1286 * unused TLB refill exception.
1287 */
1288 #define MIPS64_REFILL_INSNS 32
1289
1290 static void build_r4000_tlb_refill_handler(void)
1291 {
1292 u32 *p = tlb_handler;
1293 struct uasm_label *l = labels;
1294 struct uasm_reloc *r = relocs;
1295 u32 *f;
1296 unsigned int final_len;
1297 struct mips_huge_tlb_info htlb_info __maybe_unused;
1298 enum vmalloc64_mode vmalloc_mode __maybe_unused;
1299
1300 memset(tlb_handler, 0, sizeof(tlb_handler));
1301 memset(labels, 0, sizeof(labels));
1302 memset(relocs, 0, sizeof(relocs));
1303 memset(final_handler, 0, sizeof(final_handler));
1304
1305 if (IS_ENABLED(CONFIG_64BIT) && (scratch_reg >= 0 || scratchpad_available()) && use_bbit_insns()) {
1306 htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1,
1307 scratch_reg);
1308 vmalloc_mode = refill_scratch;
1309 } else {
1310 htlb_info.huge_pte = K0;
1311 htlb_info.restore_scratch = 0;
1312 htlb_info.need_reload_pte = true;
1313 vmalloc_mode = refill_noscratch;
1314 /*
1315 * create the plain linear handler
1316 */
1317 if (bcm1250_m3_war()) {
1318 unsigned int segbits = 44;
1319
1320 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1321 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
1322 uasm_i_xor(&p, K0, K0, K1);
1323 uasm_i_dsrl_safe(&p, K1, K0, 62);
1324 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
1325 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
1326 uasm_i_or(&p, K0, K0, K1);
1327 uasm_il_bnez(&p, &r, K0, label_leave);
1328 /* No need for uasm_i_nop */
1329 }
1330
1331 #ifdef CONFIG_64BIT
1332 build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
1333 #else
1334 build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
1335 #endif
1336
1337 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1338 build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
1339 #endif
1340
1341 build_get_ptep(&p, K0, K1);
1342 build_update_entries(&p, K0, K1);
1343 build_tlb_write_entry(&p, &l, &r, tlb_random);
1344 uasm_l_leave(&l, p);
1345 uasm_i_eret(&p); /* return from trap */
1346 }
1347 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1348 uasm_l_tlb_huge_update(&l, p);
1349 if (htlb_info.need_reload_pte)
1350 UASM_i_LW(&p, htlb_info.huge_pte, 0, K1);
1351 build_huge_update_entries(&p, htlb_info.huge_pte, K1);
1352 build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
1353 htlb_info.restore_scratch);
1354 #endif
1355
1356 #ifdef CONFIG_64BIT
1357 build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode);
1358 #endif
1359
1360 /*
1361 * Overflow check: For the 64bit handler, we need at least one
1362 * free instruction slot for the wrap-around branch. In worst
1363 * case, if the intended insertion point is a delay slot, we
1364 * need three, with the second nop'ed and the third being
1365 * unused.
1366 */
1367 switch (boot_cpu_type()) {
1368 default:
1369 if (sizeof(long) == 4) {
1370 case CPU_LOONGSON2:
1371 /* Loongson2 ebase is different than r4k, we have more space */
1372 if ((p - tlb_handler) > 64)
1373 panic("TLB refill handler space exceeded");
1374 /*
1375 * Now fold the handler in the TLB refill handler space.
1376 */
1377 f = final_handler;
1378 /* Simplest case, just copy the handler. */
1379 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1380 final_len = p - tlb_handler;
1381 break;
1382 } else {
1383 if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
1384 || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
1385 && uasm_insn_has_bdelay(relocs,
1386 tlb_handler + MIPS64_REFILL_INSNS - 3)))
1387 panic("TLB refill handler space exceeded");
1388 /*
1389 * Now fold the handler in the TLB refill handler space.
1390 */
1391 f = final_handler + MIPS64_REFILL_INSNS;
1392 if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
1393 /* Just copy the handler. */
1394 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1395 final_len = p - tlb_handler;
1396 } else {
1397 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1398 const enum label_id ls = label_tlb_huge_update;
1399 #else
1400 const enum label_id ls = label_vmalloc;
1401 #endif
1402 u32 *split;
1403 int ov = 0;
1404 int i;
1405
1406 for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
1407 ;
1408 BUG_ON(i == ARRAY_SIZE(labels));
1409 split = labels[i].addr;
1410
1411 /*
1412 * See if we have overflown one way or the other.
1413 */
1414 if (split > tlb_handler + MIPS64_REFILL_INSNS ||
1415 split < p - MIPS64_REFILL_INSNS)
1416 ov = 1;
1417
1418 if (ov) {
1419 /*
1420 * Split two instructions before the end. One
1421 * for the branch and one for the instruction
1422 * in the delay slot.
1423 */
1424 split = tlb_handler + MIPS64_REFILL_INSNS - 2;
1425
1426 /*
1427 * If the branch would fall in a delay slot,
1428 * we must back up an additional instruction
1429 * so that it is no longer in a delay slot.
1430 */
1431 if (uasm_insn_has_bdelay(relocs, split - 1))
1432 split--;
1433 }
1434 /* Copy first part of the handler. */
1435 uasm_copy_handler(relocs, labels, tlb_handler, split, f);
1436 f += split - tlb_handler;
1437
1438 if (ov) {
1439 /* Insert branch. */
1440 uasm_l_split(&l, final_handler);
1441 uasm_il_b(&f, &r, label_split);
1442 if (uasm_insn_has_bdelay(relocs, split))
1443 uasm_i_nop(&f);
1444 else {
1445 uasm_copy_handler(relocs, labels,
1446 split, split + 1, f);
1447 uasm_move_labels(labels, f, f + 1, -1);
1448 f++;
1449 split++;
1450 }
1451 }
1452
1453 /* Copy the rest of the handler. */
1454 uasm_copy_handler(relocs, labels, split, p, final_handler);
1455 final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
1456 (p - split);
1457 }
1458 }
1459 break;
1460 }
1461
1462 uasm_resolve_relocs(relocs, labels);
1463 pr_debug("Wrote TLB refill handler (%u instructions).\n",
1464 final_len);
1465
1466 memcpy((void *)ebase, final_handler, 0x100);
1467 local_flush_icache_range(ebase, ebase + 0x100);
1468
1469 dump_handler("r4000_tlb_refill", (u32 *)ebase, 64);
1470 }
1471
1472 static void setup_pw(void)
1473 {
1474 unsigned long pgd_i, pgd_w;
1475 #ifndef __PAGETABLE_PMD_FOLDED
1476 unsigned long pmd_i, pmd_w;
1477 #endif
1478 unsigned long pt_i, pt_w;
1479 unsigned long pte_i, pte_w;
1480 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1481 unsigned long psn;
1482
1483 psn = ilog2(_PAGE_HUGE); /* bit used to indicate huge page */
1484 #endif
1485 pgd_i = PGDIR_SHIFT; /* 1st level PGD */
1486 #ifndef __PAGETABLE_PMD_FOLDED
1487 pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_ORDER;
1488
1489 pmd_i = PMD_SHIFT; /* 2nd level PMD */
1490 pmd_w = PMD_SHIFT - PAGE_SHIFT;
1491 #else
1492 pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_ORDER;
1493 #endif
1494
1495 pt_i = PAGE_SHIFT; /* 3rd level PTE */
1496 pt_w = PAGE_SHIFT - 3;
1497
1498 pte_i = ilog2(_PAGE_GLOBAL);
1499 pte_w = 0;
1500
1501 #ifndef __PAGETABLE_PMD_FOLDED
1502 write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i);
1503 write_c0_pwsize(1 << 30 | pgd_w << 24 | pmd_w << 12 | pt_w << 6 | pte_w);
1504 #else
1505 write_c0_pwfield(pgd_i << 24 | pt_i << 6 | pte_i);
1506 write_c0_pwsize(1 << 30 | pgd_w << 24 | pt_w << 6 | pte_w);
1507 #endif
1508
1509 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1510 write_c0_pwctl(1 << 6 | psn);
1511 #endif
1512 write_c0_kpgd(swapper_pg_dir);
1513 kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */
1514 }
1515
1516 static void build_loongson3_tlb_refill_handler(void)
1517 {
1518 u32 *p = tlb_handler;
1519 struct uasm_label *l = labels;
1520 struct uasm_reloc *r = relocs;
1521
1522 memset(labels, 0, sizeof(labels));
1523 memset(relocs, 0, sizeof(relocs));
1524 memset(tlb_handler, 0, sizeof(tlb_handler));
1525
1526 if (check_for_high_segbits) {
1527 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1528 uasm_i_dsrl_safe(&p, K1, K0, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
1529 uasm_il_beqz(&p, &r, K1, label_vmalloc);
1530 uasm_i_nop(&p);
1531
1532 uasm_il_bgez(&p, &r, K0, label_large_segbits_fault);
1533 uasm_i_nop(&p);
1534 uasm_l_vmalloc(&l, p);
1535 }
1536
1537 uasm_i_dmfc0(&p, K1, C0_PGD);
1538
1539 uasm_i_lddir(&p, K0, K1, 3); /* global page dir */
1540 #ifndef __PAGETABLE_PMD_FOLDED
1541 uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */
1542 #endif
1543 uasm_i_ldpte(&p, K1, 0); /* even */
1544 uasm_i_ldpte(&p, K1, 1); /* odd */
1545 uasm_i_tlbwr(&p);
1546
1547 /* restore page mask */
1548 if (PM_DEFAULT_MASK >> 16) {
1549 uasm_i_lui(&p, K0, PM_DEFAULT_MASK >> 16);
1550 uasm_i_ori(&p, K0, K0, PM_DEFAULT_MASK & 0xffff);
1551 uasm_i_mtc0(&p, K0, C0_PAGEMASK);
1552 } else if (PM_DEFAULT_MASK) {
1553 uasm_i_ori(&p, K0, 0, PM_DEFAULT_MASK);
1554 uasm_i_mtc0(&p, K0, C0_PAGEMASK);
1555 } else {
1556 uasm_i_mtc0(&p, 0, C0_PAGEMASK);
1557 }
1558
1559 uasm_i_eret(&p);
1560
1561 if (check_for_high_segbits) {
1562 uasm_l_large_segbits_fault(&l, p);
1563 UASM_i_LA(&p, K1, (unsigned long)tlb_do_page_fault_0);
1564 uasm_i_jr(&p, K1);
1565 uasm_i_nop(&p);
1566 }
1567
1568 uasm_resolve_relocs(relocs, labels);
1569 memcpy((void *)(ebase + 0x80), tlb_handler, 0x80);
1570 local_flush_icache_range(ebase + 0x80, ebase + 0x100);
1571 dump_handler("loongson3_tlb_refill", (u32 *)(ebase + 0x80), 32);
1572 }
1573
1574 extern u32 handle_tlbl[], handle_tlbl_end[];
1575 extern u32 handle_tlbs[], handle_tlbs_end[];
1576 extern u32 handle_tlbm[], handle_tlbm_end[];
1577 extern u32 tlbmiss_handler_setup_pgd_start[];
1578 extern u32 tlbmiss_handler_setup_pgd[];
1579 EXPORT_SYMBOL_GPL(tlbmiss_handler_setup_pgd);
1580 extern u32 tlbmiss_handler_setup_pgd_end[];
1581
1582 static void build_setup_pgd(void)
1583 {
1584 const int a0 = 4;
1585 const int __maybe_unused a1 = 5;
1586 const int __maybe_unused a2 = 6;
1587 u32 *p = tlbmiss_handler_setup_pgd_start;
1588 const int tlbmiss_handler_setup_pgd_size =
1589 tlbmiss_handler_setup_pgd_end - tlbmiss_handler_setup_pgd_start;
1590 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1591 long pgdc = (long)pgd_current;
1592 #endif
1593
1594 memset(tlbmiss_handler_setup_pgd, 0, tlbmiss_handler_setup_pgd_size *
1595 sizeof(tlbmiss_handler_setup_pgd[0]));
1596 memset(labels, 0, sizeof(labels));
1597 memset(relocs, 0, sizeof(relocs));
1598 pgd_reg = allocate_kscratch();
1599 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
1600 if (pgd_reg == -1) {
1601 struct uasm_label *l = labels;
1602 struct uasm_reloc *r = relocs;
1603
1604 /* PGD << 11 in c0_Context */
1605 /*
1606 * If it is a ckseg0 address, convert to a physical
1607 * address. Shifting right by 29 and adding 4 will
1608 * result in zero for these addresses.
1609 *
1610 */
1611 UASM_i_SRA(&p, a1, a0, 29);
1612 UASM_i_ADDIU(&p, a1, a1, 4);
1613 uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1);
1614 uasm_i_nop(&p);
1615 uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
1616 uasm_l_tlbl_goaround1(&l, p);
1617 UASM_i_SLL(&p, a0, a0, 11);
1618 uasm_i_jr(&p, 31);
1619 UASM_i_MTC0(&p, a0, C0_CONTEXT);
1620 } else {
1621 /* PGD in c0_KScratch */
1622 uasm_i_jr(&p, 31);
1623 if (cpu_has_ldpte)
1624 UASM_i_MTC0(&p, a0, C0_PWBASE);
1625 else
1626 UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
1627 }
1628 #else
1629 #ifdef CONFIG_SMP
1630 /* Save PGD to pgd_current[smp_processor_id()] */
1631 UASM_i_CPUID_MFC0(&p, a1, SMP_CPUID_REG);
1632 UASM_i_SRL_SAFE(&p, a1, a1, SMP_CPUID_PTRSHIFT);
1633 UASM_i_LA_mostly(&p, a2, pgdc);
1634 UASM_i_ADDU(&p, a2, a2, a1);
1635 UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
1636 #else
1637 UASM_i_LA_mostly(&p, a2, pgdc);
1638 UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
1639 #endif /* SMP */
1640 uasm_i_jr(&p, 31);
1641
1642 /* if pgd_reg is allocated, save PGD also to scratch register */
1643 if (pgd_reg != -1)
1644 UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
1645 else
1646 uasm_i_nop(&p);
1647 #endif
1648 if (p >= tlbmiss_handler_setup_pgd_end)
1649 panic("tlbmiss_handler_setup_pgd space exceeded");
1650
1651 uasm_resolve_relocs(relocs, labels);
1652 pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n",
1653 (unsigned int)(p - tlbmiss_handler_setup_pgd));
1654
1655 dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd,
1656 tlbmiss_handler_setup_pgd_size);
1657 }
1658
1659 static void
1660 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
1661 {
1662 #ifdef CONFIG_SMP
1663 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1664 if (cpu_has_64bits)
1665 uasm_i_lld(p, pte, 0, ptr);
1666 else
1667 # endif
1668 UASM_i_LL(p, pte, 0, ptr);
1669 #else
1670 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1671 if (cpu_has_64bits)
1672 uasm_i_ld(p, pte, 0, ptr);
1673 else
1674 # endif
1675 UASM_i_LW(p, pte, 0, ptr);
1676 #endif
1677 }
1678
1679 static void
1680 iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
1681 unsigned int mode, unsigned int scratch)
1682 {
1683 unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
1684 unsigned int swmode = mode & ~hwmode;
1685
1686 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_64bits) {
1687 uasm_i_lui(p, scratch, swmode >> 16);
1688 uasm_i_or(p, pte, pte, scratch);
1689 BUG_ON(swmode & 0xffff);
1690 } else {
1691 uasm_i_ori(p, pte, pte, mode);
1692 }
1693
1694 #ifdef CONFIG_SMP
1695 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1696 if (cpu_has_64bits)
1697 uasm_i_scd(p, pte, 0, ptr);
1698 else
1699 # endif
1700 UASM_i_SC(p, pte, 0, ptr);
1701
1702 if (r10000_llsc_war())
1703 uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
1704 else
1705 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1706
1707 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1708 if (!cpu_has_64bits) {
1709 /* no uasm_i_nop needed */
1710 uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
1711 uasm_i_ori(p, pte, pte, hwmode);
1712 BUG_ON(hwmode & ~0xffff);
1713 uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
1714 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1715 /* no uasm_i_nop needed */
1716 uasm_i_lw(p, pte, 0, ptr);
1717 } else
1718 uasm_i_nop(p);
1719 # else
1720 uasm_i_nop(p);
1721 # endif
1722 #else
1723 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1724 if (cpu_has_64bits)
1725 uasm_i_sd(p, pte, 0, ptr);
1726 else
1727 # endif
1728 UASM_i_SW(p, pte, 0, ptr);
1729
1730 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1731 if (!cpu_has_64bits) {
1732 uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
1733 uasm_i_ori(p, pte, pte, hwmode);
1734 BUG_ON(hwmode & ~0xffff);
1735 uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
1736 uasm_i_lw(p, pte, 0, ptr);
1737 }
1738 # endif
1739 #endif
1740 }
1741
1742 /*
1743 * Check if PTE is present, if not then jump to LABEL. PTR points to
1744 * the page table where this PTE is located, PTE will be re-loaded
1745 * with it's original value.
1746 */
1747 static void
1748 build_pte_present(u32 **p, struct uasm_reloc **r,
1749 int pte, int ptr, int scratch, enum label_id lid)
1750 {
1751 int t = scratch >= 0 ? scratch : pte;
1752 int cur = pte;
1753
1754 if (cpu_has_rixi) {
1755 if (use_bbit_insns()) {
1756 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
1757 uasm_i_nop(p);
1758 } else {
1759 if (_PAGE_PRESENT_SHIFT) {
1760 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1761 cur = t;
1762 }
1763 uasm_i_andi(p, t, cur, 1);
1764 uasm_il_beqz(p, r, t, lid);
1765 if (pte == t)
1766 /* You lose the SMP race :-(*/
1767 iPTE_LW(p, pte, ptr);
1768 }
1769 } else {
1770 if (_PAGE_PRESENT_SHIFT) {
1771 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1772 cur = t;
1773 }
1774 uasm_i_andi(p, t, cur,
1775 (_PAGE_PRESENT | _PAGE_NO_READ) >> _PAGE_PRESENT_SHIFT);
1776 uasm_i_xori(p, t, t, _PAGE_PRESENT >> _PAGE_PRESENT_SHIFT);
1777 uasm_il_bnez(p, r, t, lid);
1778 if (pte == t)
1779 /* You lose the SMP race :-(*/
1780 iPTE_LW(p, pte, ptr);
1781 }
1782 }
1783
1784 /* Make PTE valid, store result in PTR. */
1785 static void
1786 build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
1787 unsigned int ptr, unsigned int scratch)
1788 {
1789 unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
1790
1791 iPTE_SW(p, r, pte, ptr, mode, scratch);
1792 }
1793
1794 /*
1795 * Check if PTE can be written to, if not branch to LABEL. Regardless
1796 * restore PTE with value from PTR when done.
1797 */
1798 static void
1799 build_pte_writable(u32 **p, struct uasm_reloc **r,
1800 unsigned int pte, unsigned int ptr, int scratch,
1801 enum label_id lid)
1802 {
1803 int t = scratch >= 0 ? scratch : pte;
1804 int cur = pte;
1805
1806 if (_PAGE_PRESENT_SHIFT) {
1807 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1808 cur = t;
1809 }
1810 uasm_i_andi(p, t, cur,
1811 (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
1812 uasm_i_xori(p, t, t,
1813 (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
1814 uasm_il_bnez(p, r, t, lid);
1815 if (pte == t)
1816 /* You lose the SMP race :-(*/
1817 iPTE_LW(p, pte, ptr);
1818 else
1819 uasm_i_nop(p);
1820 }
1821
1822 /* Make PTE writable, update software status bits as well, then store
1823 * at PTR.
1824 */
1825 static void
1826 build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
1827 unsigned int ptr, unsigned int scratch)
1828 {
1829 unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1830 | _PAGE_DIRTY);
1831
1832 iPTE_SW(p, r, pte, ptr, mode, scratch);
1833 }
1834
1835 /*
1836 * Check if PTE can be modified, if not branch to LABEL. Regardless
1837 * restore PTE with value from PTR when done.
1838 */
1839 static void
1840 build_pte_modifiable(u32 **p, struct uasm_reloc **r,
1841 unsigned int pte, unsigned int ptr, int scratch,
1842 enum label_id lid)
1843 {
1844 if (use_bbit_insns()) {
1845 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_WRITE), lid);
1846 uasm_i_nop(p);
1847 } else {
1848 int t = scratch >= 0 ? scratch : pte;
1849 uasm_i_srl(p, t, pte, _PAGE_WRITE_SHIFT);
1850 uasm_i_andi(p, t, t, 1);
1851 uasm_il_beqz(p, r, t, lid);
1852 if (pte == t)
1853 /* You lose the SMP race :-(*/
1854 iPTE_LW(p, pte, ptr);
1855 }
1856 }
1857
1858 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1859
1860
1861 /*
1862 * R3000 style TLB load/store/modify handlers.
1863 */
1864
1865 /*
1866 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1867 * Then it returns.
1868 */
1869 static void
1870 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1871 {
1872 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1873 uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1874 uasm_i_tlbwi(p);
1875 uasm_i_jr(p, tmp);
1876 uasm_i_rfe(p); /* branch delay */
1877 }
1878
1879 /*
1880 * This places the pte into ENTRYLO0 and writes it with tlbwi
1881 * or tlbwr as appropriate. This is because the index register
1882 * may have the probe fail bit set as a result of a trap on a
1883 * kseg2 access, i.e. without refill. Then it returns.
1884 */
1885 static void
1886 build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
1887 struct uasm_reloc **r, unsigned int pte,
1888 unsigned int tmp)
1889 {
1890 uasm_i_mfc0(p, tmp, C0_INDEX);
1891 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1892 uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1893 uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
1894 uasm_i_tlbwi(p); /* cp0 delay */
1895 uasm_i_jr(p, tmp);
1896 uasm_i_rfe(p); /* branch delay */
1897 uasm_l_r3000_write_probe_fail(l, *p);
1898 uasm_i_tlbwr(p); /* cp0 delay */
1899 uasm_i_jr(p, tmp);
1900 uasm_i_rfe(p); /* branch delay */
1901 }
1902
1903 static void
1904 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1905 unsigned int ptr)
1906 {
1907 long pgdc = (long)pgd_current;
1908
1909 uasm_i_mfc0(p, pte, C0_BADVADDR);
1910 uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
1911 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
1912 uasm_i_srl(p, pte, pte, 22); /* load delay */
1913 uasm_i_sll(p, pte, pte, 2);
1914 uasm_i_addu(p, ptr, ptr, pte);
1915 uasm_i_mfc0(p, pte, C0_CONTEXT);
1916 uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
1917 uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
1918 uasm_i_addu(p, ptr, ptr, pte);
1919 uasm_i_lw(p, pte, 0, ptr);
1920 uasm_i_tlbp(p); /* load delay */
1921 }
1922
1923 static void build_r3000_tlb_load_handler(void)
1924 {
1925 u32 *p = handle_tlbl;
1926 const int handle_tlbl_size = handle_tlbl_end - handle_tlbl;
1927 struct uasm_label *l = labels;
1928 struct uasm_reloc *r = relocs;
1929
1930 memset(handle_tlbl, 0, handle_tlbl_size * sizeof(handle_tlbl[0]));
1931 memset(labels, 0, sizeof(labels));
1932 memset(relocs, 0, sizeof(relocs));
1933
1934 build_r3000_tlbchange_handler_head(&p, K0, K1);
1935 build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl);
1936 uasm_i_nop(&p); /* load delay */
1937 build_make_valid(&p, &r, K0, K1, -1);
1938 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1939
1940 uasm_l_nopage_tlbl(&l, p);
1941 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1942 uasm_i_nop(&p);
1943
1944 if (p >= handle_tlbl_end)
1945 panic("TLB load handler fastpath space exceeded");
1946
1947 uasm_resolve_relocs(relocs, labels);
1948 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1949 (unsigned int)(p - handle_tlbl));
1950
1951 dump_handler("r3000_tlb_load", handle_tlbl, handle_tlbl_size);
1952 }
1953
1954 static void build_r3000_tlb_store_handler(void)
1955 {
1956 u32 *p = handle_tlbs;
1957 const int handle_tlbs_size = handle_tlbs_end - handle_tlbs;
1958 struct uasm_label *l = labels;
1959 struct uasm_reloc *r = relocs;
1960
1961 memset(handle_tlbs, 0, handle_tlbs_size * sizeof(handle_tlbs[0]));
1962 memset(labels, 0, sizeof(labels));
1963 memset(relocs, 0, sizeof(relocs));
1964
1965 build_r3000_tlbchange_handler_head(&p, K0, K1);
1966 build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs);
1967 uasm_i_nop(&p); /* load delay */
1968 build_make_write(&p, &r, K0, K1, -1);
1969 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1970
1971 uasm_l_nopage_tlbs(&l, p);
1972 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1973 uasm_i_nop(&p);
1974
1975 if (p >= handle_tlbs_end)
1976 panic("TLB store handler fastpath space exceeded");
1977
1978 uasm_resolve_relocs(relocs, labels);
1979 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1980 (unsigned int)(p - handle_tlbs));
1981
1982 dump_handler("r3000_tlb_store", handle_tlbs, handle_tlbs_size);
1983 }
1984
1985 static void build_r3000_tlb_modify_handler(void)
1986 {
1987 u32 *p = handle_tlbm;
1988 const int handle_tlbm_size = handle_tlbm_end - handle_tlbm;
1989 struct uasm_label *l = labels;
1990 struct uasm_reloc *r = relocs;
1991
1992 memset(handle_tlbm, 0, handle_tlbm_size * sizeof(handle_tlbm[0]));
1993 memset(labels, 0, sizeof(labels));
1994 memset(relocs, 0, sizeof(relocs));
1995
1996 build_r3000_tlbchange_handler_head(&p, K0, K1);
1997 build_pte_modifiable(&p, &r, K0, K1, -1, label_nopage_tlbm);
1998 uasm_i_nop(&p); /* load delay */
1999 build_make_write(&p, &r, K0, K1, -1);
2000 build_r3000_pte_reload_tlbwi(&p, K0, K1);
2001
2002 uasm_l_nopage_tlbm(&l, p);
2003 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2004 uasm_i_nop(&p);
2005
2006 if (p >= handle_tlbm_end)
2007 panic("TLB modify handler fastpath space exceeded");
2008
2009 uasm_resolve_relocs(relocs, labels);
2010 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
2011 (unsigned int)(p - handle_tlbm));
2012
2013 dump_handler("r3000_tlb_modify", handle_tlbm, handle_tlbm_size);
2014 }
2015 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
2016
2017 static bool cpu_has_tlbex_tlbp_race(void)
2018 {
2019 /*
2020 * When a Hardware Table Walker is running it can replace TLB entries
2021 * at any time, leading to a race between it & the CPU.
2022 */
2023 if (cpu_has_htw)
2024 return true;
2025
2026 /*
2027 * If the CPU shares FTLB RAM with its siblings then our entry may be
2028 * replaced at any time by a sibling performing a write to the FTLB.
2029 */
2030 if (cpu_has_shared_ftlb_ram)
2031 return true;
2032
2033 /* In all other cases there ought to be no race condition to handle */
2034 return false;
2035 }
2036
2037 /*
2038 * R4000 style TLB load/store/modify handlers.
2039 */
2040 static struct work_registers
2041 build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
2042 struct uasm_reloc **r)
2043 {
2044 struct work_registers wr = build_get_work_registers(p);
2045
2046 #ifdef CONFIG_64BIT
2047 build_get_pmde64(p, l, r, wr.r1, wr.r2); /* get pmd in ptr */
2048 #else
2049 build_get_pgde32(p, wr.r1, wr.r2); /* get pgd in ptr */
2050 #endif
2051
2052 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2053 /*
2054 * For huge tlb entries, pmd doesn't contain an address but
2055 * instead contains the tlb pte. Check the PAGE_HUGE bit and
2056 * see if we need to jump to huge tlb processing.
2057 */
2058 build_is_huge_pte(p, r, wr.r1, wr.r2, label_tlb_huge_update);
2059 #endif
2060
2061 UASM_i_MFC0(p, wr.r1, C0_BADVADDR);
2062 UASM_i_LW(p, wr.r2, 0, wr.r2);
2063 UASM_i_SRL(p, wr.r1, wr.r1, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
2064 uasm_i_andi(p, wr.r1, wr.r1, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
2065 UASM_i_ADDU(p, wr.r2, wr.r2, wr.r1);
2066
2067 #ifdef CONFIG_SMP
2068 uasm_l_smp_pgtable_change(l, *p);
2069 #endif
2070 iPTE_LW(p, wr.r1, wr.r2); /* get even pte */
2071 if (!m4kc_tlbp_war()) {
2072 build_tlb_probe_entry(p);
2073 if (cpu_has_tlbex_tlbp_race()) {
2074 /* race condition happens, leaving */
2075 uasm_i_ehb(p);
2076 uasm_i_mfc0(p, wr.r3, C0_INDEX);
2077 uasm_il_bltz(p, r, wr.r3, label_leave);
2078 uasm_i_nop(p);
2079 }
2080 }
2081 return wr;
2082 }
2083
2084 static void
2085 build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
2086 struct uasm_reloc **r, unsigned int tmp,
2087 unsigned int ptr)
2088 {
2089 uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
2090 uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
2091 build_update_entries(p, tmp, ptr);
2092 build_tlb_write_entry(p, l, r, tlb_indexed);
2093 uasm_l_leave(l, *p);
2094 build_restore_work_registers(p);
2095 uasm_i_eret(p); /* return from trap */
2096
2097 #ifdef CONFIG_64BIT
2098 build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill);
2099 #endif
2100 }
2101
2102 static void build_r4000_tlb_load_handler(void)
2103 {
2104 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl);
2105 const int handle_tlbl_size = handle_tlbl_end - handle_tlbl;
2106 struct uasm_label *l = labels;
2107 struct uasm_reloc *r = relocs;
2108 struct work_registers wr;
2109
2110 memset(handle_tlbl, 0, handle_tlbl_size * sizeof(handle_tlbl[0]));
2111 memset(labels, 0, sizeof(labels));
2112 memset(relocs, 0, sizeof(relocs));
2113
2114 if (bcm1250_m3_war()) {
2115 unsigned int segbits = 44;
2116
2117 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
2118 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
2119 uasm_i_xor(&p, K0, K0, K1);
2120 uasm_i_dsrl_safe(&p, K1, K0, 62);
2121 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
2122 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
2123 uasm_i_or(&p, K0, K0, K1);
2124 uasm_il_bnez(&p, &r, K0, label_leave);
2125 /* No need for uasm_i_nop */
2126 }
2127
2128 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2129 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
2130 if (m4kc_tlbp_war())
2131 build_tlb_probe_entry(&p);
2132
2133 if (cpu_has_rixi && !cpu_has_rixiex) {
2134 /*
2135 * If the page is not _PAGE_VALID, RI or XI could not
2136 * have triggered it. Skip the expensive test..
2137 */
2138 if (use_bbit_insns()) {
2139 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
2140 label_tlbl_goaround1);
2141 } else {
2142 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
2143 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1);
2144 }
2145 uasm_i_nop(&p);
2146
2147 /*
2148 * Warn if something may race with us & replace the TLB entry
2149 * before we read it here. Everything with such races should
2150 * also have dedicated RiXi exception handlers, so this
2151 * shouldn't be hit.
2152 */
2153 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
2154
2155 uasm_i_tlbr(&p);
2156
2157 switch (current_cpu_type()) {
2158 default:
2159 if (cpu_has_mips_r2_exec_hazard) {
2160 uasm_i_ehb(&p);
2161
2162 case CPU_CAVIUM_OCTEON:
2163 case CPU_CAVIUM_OCTEON_PLUS:
2164 case CPU_CAVIUM_OCTEON2:
2165 break;
2166 }
2167 }
2168
2169 /* Examine entrylo 0 or 1 based on ptr. */
2170 if (use_bbit_insns()) {
2171 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
2172 } else {
2173 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
2174 uasm_i_beqz(&p, wr.r3, 8);
2175 }
2176 /* load it in the delay slot*/
2177 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
2178 /* load it if ptr is odd */
2179 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
2180 /*
2181 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
2182 * XI must have triggered it.
2183 */
2184 if (use_bbit_insns()) {
2185 uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl);
2186 uasm_i_nop(&p);
2187 uasm_l_tlbl_goaround1(&l, p);
2188 } else {
2189 uasm_i_andi(&p, wr.r3, wr.r3, 2);
2190 uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl);
2191 uasm_i_nop(&p);
2192 }
2193 uasm_l_tlbl_goaround1(&l, p);
2194 }
2195 build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3);
2196 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2197
2198 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2199 /*
2200 * This is the entry point when build_r4000_tlbchange_handler_head
2201 * spots a huge page.
2202 */
2203 uasm_l_tlb_huge_update(&l, p);
2204 iPTE_LW(&p, wr.r1, wr.r2);
2205 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
2206 build_tlb_probe_entry(&p);
2207
2208 if (cpu_has_rixi && !cpu_has_rixiex) {
2209 /*
2210 * If the page is not _PAGE_VALID, RI or XI could not
2211 * have triggered it. Skip the expensive test..
2212 */
2213 if (use_bbit_insns()) {
2214 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
2215 label_tlbl_goaround2);
2216 } else {
2217 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
2218 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
2219 }
2220 uasm_i_nop(&p);
2221
2222 /*
2223 * Warn if something may race with us & replace the TLB entry
2224 * before we read it here. Everything with such races should
2225 * also have dedicated RiXi exception handlers, so this
2226 * shouldn't be hit.
2227 */
2228 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
2229
2230 uasm_i_tlbr(&p);
2231
2232 switch (current_cpu_type()) {
2233 default:
2234 if (cpu_has_mips_r2_exec_hazard) {
2235 uasm_i_ehb(&p);
2236
2237 case CPU_CAVIUM_OCTEON:
2238 case CPU_CAVIUM_OCTEON_PLUS:
2239 case CPU_CAVIUM_OCTEON2:
2240 break;
2241 }
2242 }
2243
2244 /* Examine entrylo 0 or 1 based on ptr. */
2245 if (use_bbit_insns()) {
2246 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
2247 } else {
2248 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
2249 uasm_i_beqz(&p, wr.r3, 8);
2250 }
2251 /* load it in the delay slot*/
2252 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
2253 /* load it if ptr is odd */
2254 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
2255 /*
2256 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
2257 * XI must have triggered it.
2258 */
2259 if (use_bbit_insns()) {
2260 uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2);
2261 } else {
2262 uasm_i_andi(&p, wr.r3, wr.r3, 2);
2263 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
2264 }
2265 if (PM_DEFAULT_MASK == 0)
2266 uasm_i_nop(&p);
2267 /*
2268 * We clobbered C0_PAGEMASK, restore it. On the other branch
2269 * it is restored in build_huge_tlb_write_entry.
2270 */
2271 build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0);
2272
2273 uasm_l_tlbl_goaround2(&l, p);
2274 }
2275 uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID));
2276 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
2277 #endif
2278
2279 uasm_l_nopage_tlbl(&l, p);
2280 build_restore_work_registers(&p);
2281 #ifdef CONFIG_CPU_MICROMIPS
2282 if ((unsigned long)tlb_do_page_fault_0 & 1) {
2283 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0));
2284 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0));
2285 uasm_i_jr(&p, K0);
2286 } else
2287 #endif
2288 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
2289 uasm_i_nop(&p);
2290
2291 if (p >= handle_tlbl_end)
2292 panic("TLB load handler fastpath space exceeded");
2293
2294 uasm_resolve_relocs(relocs, labels);
2295 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
2296 (unsigned int)(p - handle_tlbl));
2297
2298 dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_size);
2299 }
2300
2301 static void build_r4000_tlb_store_handler(void)
2302 {
2303 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbs);
2304 const int handle_tlbs_size = handle_tlbs_end - handle_tlbs;
2305 struct uasm_label *l = labels;
2306 struct uasm_reloc *r = relocs;
2307 struct work_registers wr;
2308
2309 memset(handle_tlbs, 0, handle_tlbs_size * sizeof(handle_tlbs[0]));
2310 memset(labels, 0, sizeof(labels));
2311 memset(relocs, 0, sizeof(relocs));
2312
2313 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2314 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2315 if (m4kc_tlbp_war())
2316 build_tlb_probe_entry(&p);
2317 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);
2318 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2319
2320 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2321 /*
2322 * This is the entry point when
2323 * build_r4000_tlbchange_handler_head spots a huge page.
2324 */
2325 uasm_l_tlb_huge_update(&l, p);
2326 iPTE_LW(&p, wr.r1, wr.r2);
2327 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2328 build_tlb_probe_entry(&p);
2329 uasm_i_ori(&p, wr.r1, wr.r1,
2330 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2331 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
2332 #endif
2333
2334 uasm_l_nopage_tlbs(&l, p);
2335 build_restore_work_registers(&p);
2336 #ifdef CONFIG_CPU_MICROMIPS
2337 if ((unsigned long)tlb_do_page_fault_1 & 1) {
2338 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
2339 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
2340 uasm_i_jr(&p, K0);
2341 } else
2342 #endif
2343 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2344 uasm_i_nop(&p);
2345
2346 if (p >= handle_tlbs_end)
2347 panic("TLB store handler fastpath space exceeded");
2348
2349 uasm_resolve_relocs(relocs, labels);
2350 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
2351 (unsigned int)(p - handle_tlbs));
2352
2353 dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_size);
2354 }
2355
2356 static void build_r4000_tlb_modify_handler(void)
2357 {
2358 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbm);
2359 const int handle_tlbm_size = handle_tlbm_end - handle_tlbm;
2360 struct uasm_label *l = labels;
2361 struct uasm_reloc *r = relocs;
2362 struct work_registers wr;
2363
2364 memset(handle_tlbm, 0, handle_tlbm_size * sizeof(handle_tlbm[0]));
2365 memset(labels, 0, sizeof(labels));
2366 memset(relocs, 0, sizeof(relocs));
2367
2368 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2369 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2370 if (m4kc_tlbp_war())
2371 build_tlb_probe_entry(&p);
2372 /* Present and writable bits set, set accessed and dirty bits. */
2373 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);
2374 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2375
2376 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2377 /*
2378 * This is the entry point when
2379 * build_r4000_tlbchange_handler_head spots a huge page.
2380 */
2381 uasm_l_tlb_huge_update(&l, p);
2382 iPTE_LW(&p, wr.r1, wr.r2);
2383 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2384 build_tlb_probe_entry(&p);
2385 uasm_i_ori(&p, wr.r1, wr.r1,
2386 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2387 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0);
2388 #endif
2389
2390 uasm_l_nopage_tlbm(&l, p);
2391 build_restore_work_registers(&p);
2392 #ifdef CONFIG_CPU_MICROMIPS
2393 if ((unsigned long)tlb_do_page_fault_1 & 1) {
2394 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
2395 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
2396 uasm_i_jr(&p, K0);
2397 } else
2398 #endif
2399 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2400 uasm_i_nop(&p);
2401
2402 if (p >= handle_tlbm_end)
2403 panic("TLB modify handler fastpath space exceeded");
2404
2405 uasm_resolve_relocs(relocs, labels);
2406 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
2407 (unsigned int)(p - handle_tlbm));
2408
2409 dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_size);
2410 }
2411
2412 static void flush_tlb_handlers(void)
2413 {
2414 local_flush_icache_range((unsigned long)handle_tlbl,
2415 (unsigned long)handle_tlbl_end);
2416 local_flush_icache_range((unsigned long)handle_tlbs,
2417 (unsigned long)handle_tlbs_end);
2418 local_flush_icache_range((unsigned long)handle_tlbm,
2419 (unsigned long)handle_tlbm_end);
2420 local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
2421 (unsigned long)tlbmiss_handler_setup_pgd_end);
2422 }
2423
2424 static void print_htw_config(void)
2425 {
2426 unsigned long config;
2427 unsigned int pwctl;
2428 const int field = 2 * sizeof(unsigned long);
2429
2430 config = read_c0_pwfield();
2431 pr_debug("PWField (0x%0*lx): GDI: 0x%02lx UDI: 0x%02lx MDI: 0x%02lx PTI: 0x%02lx PTEI: 0x%02lx\n",
2432 field, config,
2433 (config & MIPS_PWFIELD_GDI_MASK) >> MIPS_PWFIELD_GDI_SHIFT,
2434 (config & MIPS_PWFIELD_UDI_MASK) >> MIPS_PWFIELD_UDI_SHIFT,
2435 (config & MIPS_PWFIELD_MDI_MASK) >> MIPS_PWFIELD_MDI_SHIFT,
2436 (config & MIPS_PWFIELD_PTI_MASK) >> MIPS_PWFIELD_PTI_SHIFT,
2437 (config & MIPS_PWFIELD_PTEI_MASK) >> MIPS_PWFIELD_PTEI_SHIFT);
2438
2439 config = read_c0_pwsize();
2440 pr_debug("PWSize (0x%0*lx): PS: 0x%lx GDW: 0x%02lx UDW: 0x%02lx MDW: 0x%02lx PTW: 0x%02lx PTEW: 0x%02lx\n",
2441 field, config,
2442 (config & MIPS_PWSIZE_PS_MASK) >> MIPS_PWSIZE_PS_SHIFT,
2443 (config & MIPS_PWSIZE_GDW_MASK) >> MIPS_PWSIZE_GDW_SHIFT,
2444 (config & MIPS_PWSIZE_UDW_MASK) >> MIPS_PWSIZE_UDW_SHIFT,
2445 (config & MIPS_PWSIZE_MDW_MASK) >> MIPS_PWSIZE_MDW_SHIFT,
2446 (config & MIPS_PWSIZE_PTW_MASK) >> MIPS_PWSIZE_PTW_SHIFT,
2447 (config & MIPS_PWSIZE_PTEW_MASK) >> MIPS_PWSIZE_PTEW_SHIFT);
2448
2449 pwctl = read_c0_pwctl();
2450 pr_debug("PWCtl (0x%x): PWEn: 0x%x XK: 0x%x XS: 0x%x XU: 0x%x DPH: 0x%x HugePg: 0x%x Psn: 0x%x\n",
2451 pwctl,
2452 (pwctl & MIPS_PWCTL_PWEN_MASK) >> MIPS_PWCTL_PWEN_SHIFT,
2453 (pwctl & MIPS_PWCTL_XK_MASK) >> MIPS_PWCTL_XK_SHIFT,
2454 (pwctl & MIPS_PWCTL_XS_MASK) >> MIPS_PWCTL_XS_SHIFT,
2455 (pwctl & MIPS_PWCTL_XU_MASK) >> MIPS_PWCTL_XU_SHIFT,
2456 (pwctl & MIPS_PWCTL_DPH_MASK) >> MIPS_PWCTL_DPH_SHIFT,
2457 (pwctl & MIPS_PWCTL_HUGEPG_MASK) >> MIPS_PWCTL_HUGEPG_SHIFT,
2458 (pwctl & MIPS_PWCTL_PSN_MASK) >> MIPS_PWCTL_PSN_SHIFT);
2459 }
2460
2461 static void config_htw_params(void)
2462 {
2463 unsigned long pwfield, pwsize, ptei;
2464 unsigned int config;
2465
2466 /*
2467 * We are using 2-level page tables, so we only need to
2468 * setup GDW and PTW appropriately. UDW and MDW will remain 0.
2469 * The default value of GDI/UDI/MDI/PTI is 0xc. It is illegal to
2470 * write values less than 0xc in these fields because the entire
2471 * write will be dropped. As a result of which, we must preserve
2472 * the original reset values and overwrite only what we really want.
2473 */
2474
2475 pwfield = read_c0_pwfield();
2476 /* re-initialize the GDI field */
2477 pwfield &= ~MIPS_PWFIELD_GDI_MASK;
2478 pwfield |= PGDIR_SHIFT << MIPS_PWFIELD_GDI_SHIFT;
2479 /* re-initialize the PTI field including the even/odd bit */
2480 pwfield &= ~MIPS_PWFIELD_PTI_MASK;
2481 pwfield |= PAGE_SHIFT << MIPS_PWFIELD_PTI_SHIFT;
2482 if (CONFIG_PGTABLE_LEVELS >= 3) {
2483 pwfield &= ~MIPS_PWFIELD_MDI_MASK;
2484 pwfield |= PMD_SHIFT << MIPS_PWFIELD_MDI_SHIFT;
2485 }
2486 /* Set the PTEI right shift */
2487 ptei = _PAGE_GLOBAL_SHIFT << MIPS_PWFIELD_PTEI_SHIFT;
2488 pwfield |= ptei;
2489 write_c0_pwfield(pwfield);
2490 /* Check whether the PTEI value is supported */
2491 back_to_back_c0_hazard();
2492 pwfield = read_c0_pwfield();
2493 if (((pwfield & MIPS_PWFIELD_PTEI_MASK) << MIPS_PWFIELD_PTEI_SHIFT)
2494 != ptei) {
2495 pr_warn("Unsupported PTEI field value: 0x%lx. HTW will not be enabled",
2496 ptei);
2497 /*
2498 * Drop option to avoid HTW being enabled via another path
2499 * (eg htw_reset())
2500 */
2501 current_cpu_data.options &= ~MIPS_CPU_HTW;
2502 return;
2503 }
2504
2505 pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT;
2506 pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT;
2507 if (CONFIG_PGTABLE_LEVELS >= 3)
2508 pwsize |= ilog2(PTRS_PER_PMD) << MIPS_PWSIZE_MDW_SHIFT;
2509
2510 /* Set pointer size to size of directory pointers */
2511 if (IS_ENABLED(CONFIG_64BIT))
2512 pwsize |= MIPS_PWSIZE_PS_MASK;
2513 /* PTEs may be multiple pointers long (e.g. with XPA) */
2514 pwsize |= ((PTE_T_LOG2 - PGD_T_LOG2) << MIPS_PWSIZE_PTEW_SHIFT)
2515 & MIPS_PWSIZE_PTEW_MASK;
2516
2517 write_c0_pwsize(pwsize);
2518
2519 /* Make sure everything is set before we enable the HTW */
2520 back_to_back_c0_hazard();
2521
2522 /*
2523 * Enable HTW (and only for XUSeg on 64-bit), and disable the rest of
2524 * the pwctl fields.
2525 */
2526 config = 1 << MIPS_PWCTL_PWEN_SHIFT;
2527 if (IS_ENABLED(CONFIG_64BIT))
2528 config |= MIPS_PWCTL_XU_MASK;
2529 write_c0_pwctl(config);
2530 pr_info("Hardware Page Table Walker enabled\n");
2531
2532 print_htw_config();
2533 }
2534
2535 static void config_xpa_params(void)
2536 {
2537 #ifdef CONFIG_XPA
2538 unsigned int pagegrain;
2539
2540 if (mips_xpa_disabled) {
2541 pr_info("Extended Physical Addressing (XPA) disabled\n");
2542 return;
2543 }
2544
2545 pagegrain = read_c0_pagegrain();
2546 write_c0_pagegrain(pagegrain | PG_ELPA);
2547 back_to_back_c0_hazard();
2548 pagegrain = read_c0_pagegrain();
2549
2550 if (pagegrain & PG_ELPA)
2551 pr_info("Extended Physical Addressing (XPA) enabled\n");
2552 else
2553 panic("Extended Physical Addressing (XPA) disabled");
2554 #endif
2555 }
2556
2557 static void check_pabits(void)
2558 {
2559 unsigned long entry;
2560 unsigned pabits, fillbits;
2561
2562 if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
2563 /*
2564 * We'll only be making use of the fact that we can rotate bits
2565 * into the fill if the CPU supports RIXI, so don't bother
2566 * probing this for CPUs which don't.
2567 */
2568 return;
2569 }
2570
2571 write_c0_entrylo0(~0ul);
2572 back_to_back_c0_hazard();
2573 entry = read_c0_entrylo0();
2574
2575 /* clear all non-PFN bits */
2576 entry &= ~((1 << MIPS_ENTRYLO_PFN_SHIFT) - 1);
2577 entry &= ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
2578
2579 /* find a lower bound on PABITS, and upper bound on fill bits */
2580 pabits = fls_long(entry) + 6;
2581 fillbits = max_t(int, (int)BITS_PER_LONG - pabits, 0);
2582
2583 /* minus the RI & XI bits */
2584 fillbits -= min_t(unsigned, fillbits, 2);
2585
2586 if (fillbits >= ilog2(_PAGE_NO_EXEC))
2587 fill_includes_sw_bits = true;
2588
2589 pr_debug("Entry* registers contain %u fill bits\n", fillbits);
2590 }
2591
2592 void build_tlb_refill_handler(void)
2593 {
2594 /*
2595 * The refill handler is generated per-CPU, multi-node systems
2596 * may have local storage for it. The other handlers are only
2597 * needed once.
2598 */
2599 static int run_once = 0;
2600
2601 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_rixi)
2602 panic("Kernels supporting XPA currently require CPUs with RIXI");
2603
2604 output_pgtable_bits_defines();
2605 check_pabits();
2606
2607 #ifdef CONFIG_64BIT
2608 check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
2609 #endif
2610
2611 switch (current_cpu_type()) {
2612 case CPU_R2000:
2613 case CPU_R3000:
2614 case CPU_R3000A:
2615 case CPU_R3081E:
2616 case CPU_TX3912:
2617 case CPU_TX3922:
2618 case CPU_TX3927:
2619 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
2620 if (cpu_has_local_ebase)
2621 build_r3000_tlb_refill_handler();
2622 if (!run_once) {
2623 if (!cpu_has_local_ebase)
2624 build_r3000_tlb_refill_handler();
2625 build_setup_pgd();
2626 build_r3000_tlb_load_handler();
2627 build_r3000_tlb_store_handler();
2628 build_r3000_tlb_modify_handler();
2629 flush_tlb_handlers();
2630 run_once++;
2631 }
2632 #else
2633 panic("No R3000 TLB refill handler");
2634 #endif
2635 break;
2636
2637 case CPU_R8000:
2638 panic("No R8000 TLB refill handler yet");
2639 break;
2640
2641 default:
2642 if (cpu_has_ldpte)
2643 setup_pw();
2644
2645 if (!run_once) {
2646 scratch_reg = allocate_kscratch();
2647 build_setup_pgd();
2648 build_r4000_tlb_load_handler();
2649 build_r4000_tlb_store_handler();
2650 build_r4000_tlb_modify_handler();
2651 if (cpu_has_ldpte)
2652 build_loongson3_tlb_refill_handler();
2653 else if (!cpu_has_local_ebase)
2654 build_r4000_tlb_refill_handler();
2655 flush_tlb_handlers();
2656 run_once++;
2657 }
2658 if (cpu_has_local_ebase)
2659 build_r4000_tlb_refill_handler();
2660 if (cpu_has_xpa)
2661 config_xpa_params();
2662 if (cpu_has_htw)
2663 config_htw_params();
2664 }
2665 }
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