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 #include <linux/pgtable.h>
32
33 #include <asm/cacheflush.h>
34 #include <asm/cpu-type.h>
35 #include <asm/mmu_context.h>
36 #include <asm/uasm.h>
37 #include <asm/setup.h>
38 #include <asm/tlbex.h>
39
40 static int mips_xpa_disabled;
41
xpa_disable(char * s)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
r45k_bvahwbug(void)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
r4k_250MHZhwbug(void)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 extern int sb1250_m3_workaround_needed(void);
86
bcm1250_m3_war(void)87 static inline int __maybe_unused bcm1250_m3_war(void)
88 {
89 if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
90 return sb1250_m3_workaround_needed();
91 return 0;
92 }
93
r10000_llsc_war(void)94 static inline int __maybe_unused r10000_llsc_war(void)
95 {
96 return IS_ENABLED(CONFIG_WAR_R10000_LLSC);
97 }
98
use_bbit_insns(void)99 static int use_bbit_insns(void)
100 {
101 switch (current_cpu_type()) {
102 case CPU_CAVIUM_OCTEON:
103 case CPU_CAVIUM_OCTEON_PLUS:
104 case CPU_CAVIUM_OCTEON2:
105 case CPU_CAVIUM_OCTEON3:
106 return 1;
107 default:
108 return 0;
109 }
110 }
111
use_lwx_insns(void)112 static int use_lwx_insns(void)
113 {
114 switch (current_cpu_type()) {
115 case CPU_CAVIUM_OCTEON2:
116 case CPU_CAVIUM_OCTEON3:
117 return 1;
118 default:
119 return 0;
120 }
121 }
122 #if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \
123 CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
scratchpad_available(void)124 static bool scratchpad_available(void)
125 {
126 return true;
127 }
scratchpad_offset(int i)128 static int scratchpad_offset(int i)
129 {
130 /*
131 * CVMSEG starts at address -32768 and extends for
132 * CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines.
133 */
134 i += 1; /* Kernel use starts at the top and works down. */
135 return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768;
136 }
137 #else
scratchpad_available(void)138 static bool scratchpad_available(void)
139 {
140 return false;
141 }
scratchpad_offset(int i)142 static int scratchpad_offset(int i)
143 {
144 BUG();
145 /* Really unreachable, but evidently some GCC want this. */
146 return 0;
147 }
148 #endif
149 /*
150 * Found by experiment: At least some revisions of the 4kc throw under
151 * some circumstances a machine check exception, triggered by invalid
152 * values in the index register. Delaying the tlbp instruction until
153 * after the next branch, plus adding an additional nop in front of
154 * tlbwi/tlbwr avoids the invalid index register values. Nobody knows
155 * why; it's not an issue caused by the core RTL.
156 *
157 */
m4kc_tlbp_war(void)158 static int m4kc_tlbp_war(void)
159 {
160 return current_cpu_type() == CPU_4KC;
161 }
162
163 /* Handle labels (which must be positive integers). */
164 enum label_id {
165 label_second_part = 1,
166 label_leave,
167 label_vmalloc,
168 label_vmalloc_done,
169 label_tlbw_hazard_0,
170 label_split = label_tlbw_hazard_0 + 8,
171 label_tlbl_goaround1,
172 label_tlbl_goaround2,
173 label_nopage_tlbl,
174 label_nopage_tlbs,
175 label_nopage_tlbm,
176 label_smp_pgtable_change,
177 label_r3000_write_probe_fail,
178 label_large_segbits_fault,
179 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
180 label_tlb_huge_update,
181 #endif
182 };
183
184 UASM_L_LA(_second_part)
185 UASM_L_LA(_leave)
186 UASM_L_LA(_vmalloc)
187 UASM_L_LA(_vmalloc_done)
188 /* _tlbw_hazard_x is handled differently. */
189 UASM_L_LA(_split)
190 UASM_L_LA(_tlbl_goaround1)
191 UASM_L_LA(_tlbl_goaround2)
192 UASM_L_LA(_nopage_tlbl)
193 UASM_L_LA(_nopage_tlbs)
194 UASM_L_LA(_nopage_tlbm)
195 UASM_L_LA(_smp_pgtable_change)
196 UASM_L_LA(_r3000_write_probe_fail)
197 UASM_L_LA(_large_segbits_fault)
198 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
199 UASM_L_LA(_tlb_huge_update)
200 #endif
201
202 static int hazard_instance;
203
uasm_bgezl_hazard(u32 ** p,struct uasm_reloc ** r,int instance)204 static void uasm_bgezl_hazard(u32 **p, struct uasm_reloc **r, int instance)
205 {
206 switch (instance) {
207 case 0 ... 7:
208 uasm_il_bgezl(p, r, 0, label_tlbw_hazard_0 + instance);
209 return;
210 default:
211 BUG();
212 }
213 }
214
uasm_bgezl_label(struct uasm_label ** l,u32 ** p,int instance)215 static void uasm_bgezl_label(struct uasm_label **l, u32 **p, int instance)
216 {
217 switch (instance) {
218 case 0 ... 7:
219 uasm_build_label(l, *p, label_tlbw_hazard_0 + instance);
220 break;
221 default:
222 BUG();
223 }
224 }
225
226 /*
227 * pgtable bits are assigned dynamically depending on processor feature
228 * and statically based on kernel configuration. This spits out the actual
229 * values the kernel is using. Required to make sense from disassembled
230 * TLB exception handlers.
231 */
output_pgtable_bits_defines(void)232 static void output_pgtable_bits_defines(void)
233 {
234 #define pr_define(fmt, ...) \
235 pr_debug("#define " fmt, ##__VA_ARGS__)
236
237 pr_debug("#include <asm/asm.h>\n");
238 pr_debug("#include <asm/regdef.h>\n");
239 pr_debug("\n");
240
241 pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
242 pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
243 pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
244 pr_define("_PAGE_ACCESSED_SHIFT %d\n", _PAGE_ACCESSED_SHIFT);
245 pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);
246 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
247 pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
248 #endif
249 #ifdef _PAGE_NO_EXEC_SHIFT
250 if (cpu_has_rixi)
251 pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
252 #endif
253 pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
254 pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
255 pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
256 pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
257 pr_debug("\n");
258 }
259
dump_handler(const char * symbol,const void * start,const void * end)260 static inline void dump_handler(const char *symbol, const void *start, const void *end)
261 {
262 unsigned int count = (end - start) / sizeof(u32);
263 const u32 *handler = start;
264 int i;
265
266 pr_debug("LEAF(%s)\n", symbol);
267
268 pr_debug("\t.set push\n");
269 pr_debug("\t.set noreorder\n");
270
271 for (i = 0; i < count; i++)
272 pr_debug("\t.word\t0x%08x\t\t# %p\n", handler[i], &handler[i]);
273
274 pr_debug("\t.set\tpop\n");
275
276 pr_debug("\tEND(%s)\n", symbol);
277 }
278
279 /* The only general purpose registers allowed in TLB handlers. */
280 #define K0 26
281 #define K1 27
282
283 /* Some CP0 registers */
284 #define C0_INDEX 0, 0
285 #define C0_ENTRYLO0 2, 0
286 #define C0_TCBIND 2, 2
287 #define C0_ENTRYLO1 3, 0
288 #define C0_CONTEXT 4, 0
289 #define C0_PAGEMASK 5, 0
290 #define C0_PWBASE 5, 5
291 #define C0_PWFIELD 5, 6
292 #define C0_PWSIZE 5, 7
293 #define C0_PWCTL 6, 6
294 #define C0_BADVADDR 8, 0
295 #define C0_PGD 9, 7
296 #define C0_ENTRYHI 10, 0
297 #define C0_EPC 14, 0
298 #define C0_XCONTEXT 20, 0
299
300 #ifdef CONFIG_64BIT
301 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT)
302 #else
303 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT)
304 #endif
305
306 /* The worst case length of the handler is around 18 instructions for
307 * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
308 * Maximum space available is 32 instructions for R3000 and 64
309 * instructions for R4000.
310 *
311 * We deliberately chose a buffer size of 128, so we won't scribble
312 * over anything important on overflow before we panic.
313 */
314 static u32 tlb_handler[128];
315
316 /* simply assume worst case size for labels and relocs */
317 static struct uasm_label labels[128];
318 static struct uasm_reloc relocs[128];
319
320 static int check_for_high_segbits;
321 static bool fill_includes_sw_bits;
322
323 static unsigned int kscratch_used_mask;
324
c0_kscratch(void)325 static inline int __maybe_unused c0_kscratch(void)
326 {
327 return 31;
328 }
329
allocate_kscratch(void)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
build_get_work_registers(u32 ** p)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
build_restore_work_registers(u32 ** p)388 static void build_restore_work_registers(u32 **p)
389 {
390 if (scratch_reg >= 0) {
391 uasm_i_ehb(p);
392 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
393 return;
394 }
395 /* K0 already points to save area, restore $1 and $2 */
396 UASM_i_LW(p, 1, offsetof(struct tlb_reg_save, a), K0);
397 UASM_i_LW(p, 2, offsetof(struct tlb_reg_save, b), K0);
398 }
399
400 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
401
402 /*
403 * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current,
404 * we cannot do r3000 under these circumstances.
405 *
406 * The R3000 TLB handler is simple.
407 */
build_r3000_tlb_refill_handler(void)408 static void build_r3000_tlb_refill_handler(void)
409 {
410 long pgdc = (long)pgd_current;
411 u32 *p;
412
413 memset(tlb_handler, 0, sizeof(tlb_handler));
414 p = tlb_handler;
415
416 uasm_i_mfc0(&p, K0, C0_BADVADDR);
417 uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */
418 uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1);
419 uasm_i_srl(&p, K0, K0, 22); /* load delay */
420 uasm_i_sll(&p, K0, K0, 2);
421 uasm_i_addu(&p, K1, K1, K0);
422 uasm_i_mfc0(&p, K0, C0_CONTEXT);
423 uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */
424 uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */
425 uasm_i_addu(&p, K1, K1, K0);
426 uasm_i_lw(&p, K0, 0, K1);
427 uasm_i_nop(&p); /* load delay */
428 uasm_i_mtc0(&p, K0, C0_ENTRYLO0);
429 uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
430 uasm_i_tlbwr(&p); /* cp0 delay */
431 uasm_i_jr(&p, K1);
432 uasm_i_rfe(&p); /* branch delay */
433
434 if (p > tlb_handler + 32)
435 panic("TLB refill handler space exceeded");
436
437 pr_debug("Wrote TLB refill handler (%u instructions).\n",
438 (unsigned int)(p - tlb_handler));
439
440 memcpy((void *)ebase, tlb_handler, 0x80);
441 local_flush_icache_range(ebase, ebase + 0x80);
442 dump_handler("r3000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x80));
443 }
444 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
445
446 /*
447 * The R4000 TLB handler is much more complicated. We have two
448 * consecutive handler areas with 32 instructions space each.
449 * Since they aren't used at the same time, we can overflow in the
450 * other one.To keep things simple, we first assume linear space,
451 * then we relocate it to the final handler layout as needed.
452 */
453 static u32 final_handler[64];
454
455 /*
456 * Hazards
457 *
458 * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
459 * 2. A timing hazard exists for the TLBP instruction.
460 *
461 * stalling_instruction
462 * TLBP
463 *
464 * The JTLB is being read for the TLBP throughout the stall generated by the
465 * previous instruction. This is not really correct as the stalling instruction
466 * can modify the address used to access the JTLB. The failure symptom is that
467 * the TLBP instruction will use an address created for the stalling instruction
468 * and not the address held in C0_ENHI and thus report the wrong results.
469 *
470 * The software work-around is to not allow the instruction preceding the TLBP
471 * to stall - make it an NOP or some other instruction guaranteed not to stall.
472 *
473 * Errata 2 will not be fixed. This errata is also on the R5000.
474 *
475 * As if we MIPS hackers wouldn't know how to nop pipelines happy ...
476 */
build_tlb_probe_entry(u32 ** p)477 static void __maybe_unused build_tlb_probe_entry(u32 **p)
478 {
479 switch (current_cpu_type()) {
480 /* Found by experiment: R4600 v2.0/R4700 needs this, too. */
481 case CPU_R4600:
482 case CPU_R4700:
483 case CPU_R5000:
484 case CPU_NEVADA:
485 uasm_i_nop(p);
486 uasm_i_tlbp(p);
487 break;
488
489 default:
490 uasm_i_tlbp(p);
491 break;
492 }
493 }
494
build_tlb_write_entry(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,enum tlb_write_entry wmode)495 void build_tlb_write_entry(u32 **p, struct uasm_label **l,
496 struct uasm_reloc **r,
497 enum tlb_write_entry wmode)
498 {
499 void(*tlbw)(u32 **) = NULL;
500
501 switch (wmode) {
502 case tlb_random: tlbw = uasm_i_tlbwr; break;
503 case tlb_indexed: tlbw = uasm_i_tlbwi; break;
504 }
505
506 if (cpu_has_mips_r2_r6) {
507 if (cpu_has_mips_r2_exec_hazard)
508 uasm_i_ehb(p);
509 tlbw(p);
510 return;
511 }
512
513 switch (current_cpu_type()) {
514 case CPU_R4000PC:
515 case CPU_R4000SC:
516 case CPU_R4000MC:
517 case CPU_R4400PC:
518 case CPU_R4400SC:
519 case CPU_R4400MC:
520 /*
521 * This branch uses up a mtc0 hazard nop slot and saves
522 * two nops after the tlbw instruction.
523 */
524 uasm_bgezl_hazard(p, r, hazard_instance);
525 tlbw(p);
526 uasm_bgezl_label(l, p, hazard_instance);
527 hazard_instance++;
528 uasm_i_nop(p);
529 break;
530
531 case CPU_R4600:
532 case CPU_R4700:
533 uasm_i_nop(p);
534 tlbw(p);
535 uasm_i_nop(p);
536 break;
537
538 case CPU_R5000:
539 case CPU_NEVADA:
540 uasm_i_nop(p); /* QED specifies 2 nops hazard */
541 uasm_i_nop(p); /* QED specifies 2 nops hazard */
542 tlbw(p);
543 break;
544
545 case CPU_R4300:
546 case CPU_5KC:
547 case CPU_TX49XX:
548 case CPU_PR4450:
549 uasm_i_nop(p);
550 tlbw(p);
551 break;
552
553 case CPU_R10000:
554 case CPU_R12000:
555 case CPU_R14000:
556 case CPU_R16000:
557 case CPU_4KC:
558 case CPU_4KEC:
559 case CPU_M14KC:
560 case CPU_M14KEC:
561 case CPU_SB1:
562 case CPU_SB1A:
563 case CPU_4KSC:
564 case CPU_20KC:
565 case CPU_25KF:
566 case CPU_BMIPS32:
567 case CPU_BMIPS3300:
568 case CPU_BMIPS4350:
569 case CPU_BMIPS4380:
570 case CPU_BMIPS5000:
571 case CPU_LOONGSON2EF:
572 case CPU_LOONGSON64:
573 case CPU_R5500:
574 if (m4kc_tlbp_war())
575 uasm_i_nop(p);
576 fallthrough;
577 case CPU_ALCHEMY:
578 tlbw(p);
579 break;
580
581 case CPU_RM7000:
582 uasm_i_nop(p);
583 uasm_i_nop(p);
584 uasm_i_nop(p);
585 uasm_i_nop(p);
586 tlbw(p);
587 break;
588
589 case CPU_XBURST:
590 tlbw(p);
591 uasm_i_nop(p);
592 break;
593
594 default:
595 panic("No TLB refill handler yet (CPU type: %d)",
596 current_cpu_type());
597 break;
598 }
599 }
600 EXPORT_SYMBOL_GPL(build_tlb_write_entry);
601
build_convert_pte_to_entrylo(u32 ** p,unsigned int reg)602 static __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
603 unsigned int reg)
604 {
605 if (_PAGE_GLOBAL_SHIFT == 0) {
606 /* pte_t is already in EntryLo format */
607 return;
608 }
609
610 if (cpu_has_rixi && _PAGE_NO_EXEC != 0) {
611 if (fill_includes_sw_bits) {
612 UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
613 } else {
614 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_NO_EXEC));
615 UASM_i_ROTR(p, reg, reg,
616 ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
617 }
618 } else {
619 #ifdef CONFIG_PHYS_ADDR_T_64BIT
620 uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL));
621 #else
622 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL));
623 #endif
624 }
625 }
626
627 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
628
build_restore_pagemask(u32 ** p,struct uasm_reloc ** r,unsigned int tmp,enum label_id lid,int restore_scratch)629 static void build_restore_pagemask(u32 **p, struct uasm_reloc **r,
630 unsigned int tmp, enum label_id lid,
631 int restore_scratch)
632 {
633 if (restore_scratch) {
634 /*
635 * Ensure the MFC0 below observes the value written to the
636 * KScratch register by the prior MTC0.
637 */
638 if (scratch_reg >= 0)
639 uasm_i_ehb(p);
640
641 /* Reset default page size */
642 if (PM_DEFAULT_MASK >> 16) {
643 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
644 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
645 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
646 uasm_il_b(p, r, lid);
647 } else if (PM_DEFAULT_MASK) {
648 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
649 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
650 uasm_il_b(p, r, lid);
651 } else {
652 uasm_i_mtc0(p, 0, C0_PAGEMASK);
653 uasm_il_b(p, r, lid);
654 }
655 if (scratch_reg >= 0)
656 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
657 else
658 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
659 } else {
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_il_b(p, r, lid);
665 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
666 } else if (PM_DEFAULT_MASK) {
667 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
668 uasm_il_b(p, r, lid);
669 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
670 } else {
671 uasm_il_b(p, r, lid);
672 uasm_i_mtc0(p, 0, C0_PAGEMASK);
673 }
674 }
675 }
676
build_huge_tlb_write_entry(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,unsigned int tmp,enum tlb_write_entry wmode,int restore_scratch)677 static void build_huge_tlb_write_entry(u32 **p, struct uasm_label **l,
678 struct uasm_reloc **r,
679 unsigned int tmp,
680 enum tlb_write_entry wmode,
681 int restore_scratch)
682 {
683 /* Set huge page tlb entry size */
684 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
685 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
686 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
687
688 build_tlb_write_entry(p, l, r, wmode);
689
690 build_restore_pagemask(p, r, tmp, label_leave, restore_scratch);
691 }
692
693 /*
694 * Check if Huge PTE is present, if so then jump to LABEL.
695 */
696 static void
build_is_huge_pte(u32 ** p,struct uasm_reloc ** r,unsigned int tmp,unsigned int pmd,int lid)697 build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
698 unsigned int pmd, int lid)
699 {
700 UASM_i_LW(p, tmp, 0, pmd);
701 if (use_bbit_insns()) {
702 uasm_il_bbit1(p, r, tmp, ilog2(_PAGE_HUGE), lid);
703 } else {
704 uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
705 uasm_il_bnez(p, r, tmp, lid);
706 }
707 }
708
build_huge_update_entries(u32 ** p,unsigned int pte,unsigned int tmp)709 static void build_huge_update_entries(u32 **p, unsigned int pte,
710 unsigned int tmp)
711 {
712 int small_sequence;
713
714 /*
715 * A huge PTE describes an area the size of the
716 * configured huge page size. This is twice the
717 * of the large TLB entry size we intend to use.
718 * A TLB entry half the size of the configured
719 * huge page size is configured into entrylo0
720 * and entrylo1 to cover the contiguous huge PTE
721 * address space.
722 */
723 small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
724
725 /* We can clobber tmp. It isn't used after this.*/
726 if (!small_sequence)
727 uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
728
729 build_convert_pte_to_entrylo(p, pte);
730 UASM_i_MTC0(p, pte, C0_ENTRYLO0); /* load it */
731 /* convert to entrylo1 */
732 if (small_sequence)
733 UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
734 else
735 UASM_i_ADDU(p, pte, pte, tmp);
736
737 UASM_i_MTC0(p, pte, C0_ENTRYLO1); /* load it */
738 }
739
build_huge_handler_tail(u32 ** p,struct uasm_reloc ** r,struct uasm_label ** l,unsigned int pte,unsigned int ptr,unsigned int flush)740 static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r,
741 struct uasm_label **l,
742 unsigned int pte,
743 unsigned int ptr,
744 unsigned int flush)
745 {
746 #ifdef CONFIG_SMP
747 UASM_i_SC(p, pte, 0, ptr);
748 uasm_il_beqz(p, r, pte, label_tlb_huge_update);
749 UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
750 #else
751 UASM_i_SW(p, pte, 0, ptr);
752 #endif
753 if (cpu_has_ftlb && flush) {
754 BUG_ON(!cpu_has_tlbinv);
755
756 UASM_i_MFC0(p, ptr, C0_ENTRYHI);
757 uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
758 UASM_i_MTC0(p, ptr, C0_ENTRYHI);
759 build_tlb_write_entry(p, l, r, tlb_indexed);
760
761 uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
762 UASM_i_MTC0(p, ptr, C0_ENTRYHI);
763 build_huge_update_entries(p, pte, ptr);
764 build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0);
765
766 return;
767 }
768
769 build_huge_update_entries(p, pte, ptr);
770 build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
771 }
772 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
773
774 #ifdef CONFIG_64BIT
775 /*
776 * TMP and PTR are scratch.
777 * TMP will be clobbered, PTR will hold the pmd entry.
778 */
build_get_pmde64(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,unsigned int tmp,unsigned int ptr)779 void build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
780 unsigned int tmp, unsigned int ptr)
781 {
782 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
783 long pgdc = (long)pgd_current;
784 #endif
785 /*
786 * The vmalloc handling is not in the hotpath.
787 */
788 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
789
790 if (check_for_high_segbits) {
791 /*
792 * The kernel currently implicitely assumes that the
793 * MIPS SEGBITS parameter for the processor is
794 * (PGDIR_SHIFT+PGDIR_BITS) or less, and will never
795 * allocate virtual addresses outside the maximum
796 * range for SEGBITS = (PGDIR_SHIFT+PGDIR_BITS). But
797 * that doesn't prevent user code from accessing the
798 * higher xuseg addresses. Here, we make sure that
799 * everything but the lower xuseg addresses goes down
800 * the module_alloc/vmalloc path.
801 */
802 uasm_i_dsrl_safe(p, ptr, tmp, PGDIR_SHIFT + PGD_TABLE_ORDER + PAGE_SHIFT - 3);
803 uasm_il_bnez(p, r, ptr, label_vmalloc);
804 } else {
805 uasm_il_bltz(p, r, tmp, label_vmalloc);
806 }
807 /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
808
809 if (pgd_reg != -1) {
810 /* pgd is in pgd_reg */
811 if (cpu_has_ldpte)
812 UASM_i_MFC0(p, ptr, C0_PWBASE);
813 else
814 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
815 } else {
816 #if defined(CONFIG_MIPS_PGD_C0_CONTEXT)
817 /*
818 * &pgd << 11 stored in CONTEXT [23..63].
819 */
820 UASM_i_MFC0(p, ptr, C0_CONTEXT);
821
822 /* Clear lower 23 bits of context. */
823 uasm_i_dins(p, ptr, 0, 0, 23);
824
825 /* insert bit[63:59] of CAC_BASE into bit[11:6] of ptr */
826 uasm_i_ori(p, ptr, ptr, ((u64)(CAC_BASE) >> 53));
827 uasm_i_drotr(p, ptr, ptr, 11);
828 #elif defined(CONFIG_SMP)
829 UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG);
830 uasm_i_dsrl_safe(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
831 UASM_i_LA_mostly(p, tmp, pgdc);
832 uasm_i_daddu(p, ptr, ptr, tmp);
833 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
834 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
835 #else
836 UASM_i_LA_mostly(p, ptr, pgdc);
837 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
838 #endif
839 }
840
841 uasm_l_vmalloc_done(l, *p);
842
843 /* get pgd offset in bytes */
844 uasm_i_dsrl_safe(p, tmp, tmp, PGDIR_SHIFT - 3);
845
846 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
847 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
848 #ifndef __PAGETABLE_PUD_FOLDED
849 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
850 uasm_i_ld(p, ptr, 0, ptr); /* get pud pointer */
851 uasm_i_dsrl_safe(p, tmp, tmp, PUD_SHIFT - 3); /* get pud offset in bytes */
852 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PUD - 1) << 3);
853 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pud offset */
854 #endif
855 #ifndef __PAGETABLE_PMD_FOLDED
856 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
857 uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
858 uasm_i_dsrl_safe(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
859 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
860 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
861 #endif
862 }
863 EXPORT_SYMBOL_GPL(build_get_pmde64);
864
865 /*
866 * BVADDR is the faulting address, PTR is scratch.
867 * PTR will hold the pgd for vmalloc.
868 */
869 static void
build_get_pgd_vmalloc64(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,unsigned int bvaddr,unsigned int ptr,enum vmalloc64_mode mode)870 build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
871 unsigned int bvaddr, unsigned int ptr,
872 enum vmalloc64_mode mode)
873 {
874 long swpd = (long)swapper_pg_dir;
875 int single_insn_swpd;
876 int did_vmalloc_branch = 0;
877
878 single_insn_swpd = uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd);
879
880 uasm_l_vmalloc(l, *p);
881
882 if (mode != not_refill && check_for_high_segbits) {
883 if (single_insn_swpd) {
884 uasm_il_bltz(p, r, bvaddr, label_vmalloc_done);
885 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
886 did_vmalloc_branch = 1;
887 /* fall through */
888 } else {
889 uasm_il_bgez(p, r, bvaddr, label_large_segbits_fault);
890 }
891 }
892 if (!did_vmalloc_branch) {
893 if (single_insn_swpd) {
894 uasm_il_b(p, r, label_vmalloc_done);
895 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
896 } else {
897 UASM_i_LA_mostly(p, ptr, swpd);
898 uasm_il_b(p, r, label_vmalloc_done);
899 if (uasm_in_compat_space_p(swpd))
900 uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
901 else
902 uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
903 }
904 }
905 if (mode != not_refill && check_for_high_segbits) {
906 uasm_l_large_segbits_fault(l, *p);
907
908 if (mode == refill_scratch && scratch_reg >= 0)
909 uasm_i_ehb(p);
910
911 /*
912 * We get here if we are an xsseg address, or if we are
913 * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary.
914 *
915 * Ignoring xsseg (assume disabled so would generate
916 * (address errors?), the only remaining possibility
917 * is the upper xuseg addresses. On processors with
918 * TLB_SEGBITS <= PGDIR_SHIFT+PGDIR_BITS, these
919 * addresses would have taken an address error. We try
920 * to mimic that here by taking a load/istream page
921 * fault.
922 */
923 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
924 uasm_i_sync(p, 0);
925 UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
926 uasm_i_jr(p, ptr);
927
928 if (mode == refill_scratch) {
929 if (scratch_reg >= 0)
930 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
931 else
932 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
933 } else {
934 uasm_i_nop(p);
935 }
936 }
937 }
938
939 #else /* !CONFIG_64BIT */
940
941 /*
942 * TMP and PTR are scratch.
943 * TMP will be clobbered, PTR will hold the pgd entry.
944 */
build_get_pgde32(u32 ** p,unsigned int tmp,unsigned int ptr)945 void build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
946 {
947 if (pgd_reg != -1) {
948 /* pgd is in pgd_reg */
949 uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg);
950 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
951 } else {
952 long pgdc = (long)pgd_current;
953
954 /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
955 #ifdef CONFIG_SMP
956 uasm_i_mfc0(p, ptr, SMP_CPUID_REG);
957 UASM_i_LA_mostly(p, tmp, pgdc);
958 uasm_i_srl(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
959 uasm_i_addu(p, ptr, tmp, ptr);
960 #else
961 UASM_i_LA_mostly(p, ptr, pgdc);
962 #endif
963 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
964 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
965 }
966 uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
967 uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
968 uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
969 }
970 EXPORT_SYMBOL_GPL(build_get_pgde32);
971
972 #endif /* !CONFIG_64BIT */
973
build_adjust_context(u32 ** p,unsigned int ctx)974 static void build_adjust_context(u32 **p, unsigned int ctx)
975 {
976 unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
977 unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
978
979 if (shift)
980 UASM_i_SRL(p, ctx, ctx, shift);
981 uasm_i_andi(p, ctx, ctx, mask);
982 }
983
build_get_ptep(u32 ** p,unsigned int tmp,unsigned int ptr)984 void build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
985 {
986 /*
987 * Bug workaround for the Nevada. It seems as if under certain
988 * circumstances the move from cp0_context might produce a
989 * bogus result when the mfc0 instruction and its consumer are
990 * in a different cacheline or a load instruction, probably any
991 * memory reference, is between them.
992 */
993 switch (current_cpu_type()) {
994 case CPU_NEVADA:
995 UASM_i_LW(p, ptr, 0, ptr);
996 GET_CONTEXT(p, tmp); /* get context reg */
997 break;
998
999 default:
1000 GET_CONTEXT(p, tmp); /* get context reg */
1001 UASM_i_LW(p, ptr, 0, ptr);
1002 break;
1003 }
1004
1005 build_adjust_context(p, tmp);
1006 UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
1007 }
1008 EXPORT_SYMBOL_GPL(build_get_ptep);
1009
build_update_entries(u32 ** p,unsigned int tmp,unsigned int ptep)1010 void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
1011 {
1012 int pte_off_even = 0;
1013 int pte_off_odd = sizeof(pte_t);
1014
1015 #if defined(CONFIG_CPU_MIPS32) && defined(CONFIG_PHYS_ADDR_T_64BIT)
1016 /* The low 32 bits of EntryLo is stored in pte_high */
1017 pte_off_even += offsetof(pte_t, pte_high);
1018 pte_off_odd += offsetof(pte_t, pte_high);
1019 #endif
1020
1021 if (IS_ENABLED(CONFIG_XPA)) {
1022 uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */
1023 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
1024 UASM_i_MTC0(p, tmp, C0_ENTRYLO0);
1025
1026 if (cpu_has_xpa && !mips_xpa_disabled) {
1027 uasm_i_lw(p, tmp, 0, ptep);
1028 uasm_i_ext(p, tmp, tmp, 0, 24);
1029 uasm_i_mthc0(p, tmp, C0_ENTRYLO0);
1030 }
1031
1032 uasm_i_lw(p, tmp, pte_off_odd, ptep); /* odd pte */
1033 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
1034 UASM_i_MTC0(p, tmp, C0_ENTRYLO1);
1035
1036 if (cpu_has_xpa && !mips_xpa_disabled) {
1037 uasm_i_lw(p, tmp, sizeof(pte_t), ptep);
1038 uasm_i_ext(p, tmp, tmp, 0, 24);
1039 uasm_i_mthc0(p, tmp, C0_ENTRYLO1);
1040 }
1041 return;
1042 }
1043
1044 UASM_i_LW(p, tmp, pte_off_even, ptep); /* get even pte */
1045 UASM_i_LW(p, ptep, pte_off_odd, ptep); /* get odd pte */
1046 if (r45k_bvahwbug())
1047 build_tlb_probe_entry(p);
1048 build_convert_pte_to_entrylo(p, tmp);
1049 if (r4k_250MHZhwbug())
1050 UASM_i_MTC0(p, 0, C0_ENTRYLO0);
1051 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
1052 build_convert_pte_to_entrylo(p, ptep);
1053 if (r45k_bvahwbug())
1054 uasm_i_mfc0(p, tmp, C0_INDEX);
1055 if (r4k_250MHZhwbug())
1056 UASM_i_MTC0(p, 0, C0_ENTRYLO1);
1057 UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
1058 }
1059 EXPORT_SYMBOL_GPL(build_update_entries);
1060
1061 struct mips_huge_tlb_info {
1062 int huge_pte;
1063 int restore_scratch;
1064 bool need_reload_pte;
1065 };
1066
1067 static struct mips_huge_tlb_info
build_fast_tlb_refill_handler(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,unsigned int tmp,unsigned int ptr,int c0_scratch_reg)1068 build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
1069 struct uasm_reloc **r, unsigned int tmp,
1070 unsigned int ptr, int c0_scratch_reg)
1071 {
1072 struct mips_huge_tlb_info rv;
1073 unsigned int even, odd;
1074 int vmalloc_branch_delay_filled = 0;
1075 const int scratch = 1; /* Our extra working register */
1076
1077 rv.huge_pte = scratch;
1078 rv.restore_scratch = 0;
1079 rv.need_reload_pte = false;
1080
1081 if (check_for_high_segbits) {
1082 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1083
1084 if (pgd_reg != -1)
1085 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
1086 else
1087 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1088
1089 if (c0_scratch_reg >= 0)
1090 UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1091 else
1092 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1093
1094 uasm_i_dsrl_safe(p, scratch, tmp,
1095 PGDIR_SHIFT + PGD_TABLE_ORDER + PAGE_SHIFT - 3);
1096 uasm_il_bnez(p, r, scratch, label_vmalloc);
1097
1098 if (pgd_reg == -1) {
1099 vmalloc_branch_delay_filled = 1;
1100 /* Clear lower 23 bits of context. */
1101 uasm_i_dins(p, ptr, 0, 0, 23);
1102 }
1103 } else {
1104 if (pgd_reg != -1)
1105 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
1106 else
1107 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1108
1109 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1110
1111 if (c0_scratch_reg >= 0)
1112 UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1113 else
1114 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1115
1116 if (pgd_reg == -1)
1117 /* Clear lower 23 bits of context. */
1118 uasm_i_dins(p, ptr, 0, 0, 23);
1119
1120 uasm_il_bltz(p, r, tmp, label_vmalloc);
1121 }
1122
1123 if (pgd_reg == -1) {
1124 vmalloc_branch_delay_filled = 1;
1125 /* insert bit[63:59] of CAC_BASE into bit[11:6] of ptr */
1126 uasm_i_ori(p, ptr, ptr, ((u64)(CAC_BASE) >> 53));
1127
1128 uasm_i_drotr(p, ptr, ptr, 11);
1129 }
1130
1131 #ifdef __PAGETABLE_PMD_FOLDED
1132 #define LOC_PTEP scratch
1133 #else
1134 #define LOC_PTEP ptr
1135 #endif
1136
1137 if (!vmalloc_branch_delay_filled)
1138 /* get pgd offset in bytes */
1139 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1140
1141 uasm_l_vmalloc_done(l, *p);
1142
1143 /*
1144 * tmp ptr
1145 * fall-through case = badvaddr *pgd_current
1146 * vmalloc case = badvaddr swapper_pg_dir
1147 */
1148
1149 if (vmalloc_branch_delay_filled)
1150 /* get pgd offset in bytes */
1151 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1152
1153 #ifdef __PAGETABLE_PMD_FOLDED
1154 GET_CONTEXT(p, tmp); /* get context reg */
1155 #endif
1156 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3);
1157
1158 if (use_lwx_insns()) {
1159 UASM_i_LWX(p, LOC_PTEP, scratch, ptr);
1160 } else {
1161 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */
1162 uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */
1163 }
1164
1165 #ifndef __PAGETABLE_PUD_FOLDED
1166 /* get pud offset in bytes */
1167 uasm_i_dsrl_safe(p, scratch, tmp, PUD_SHIFT - 3);
1168 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PUD - 1) << 3);
1169
1170 if (use_lwx_insns()) {
1171 UASM_i_LWX(p, ptr, scratch, ptr);
1172 } else {
1173 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1174 UASM_i_LW(p, ptr, 0, ptr);
1175 }
1176 /* ptr contains a pointer to PMD entry */
1177 /* tmp contains the address */
1178 #endif
1179
1180 #ifndef __PAGETABLE_PMD_FOLDED
1181 /* get pmd offset in bytes */
1182 uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3);
1183 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3);
1184 GET_CONTEXT(p, tmp); /* get context reg */
1185
1186 if (use_lwx_insns()) {
1187 UASM_i_LWX(p, scratch, scratch, ptr);
1188 } else {
1189 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1190 UASM_i_LW(p, scratch, 0, ptr);
1191 }
1192 #endif
1193 /* Adjust the context during the load latency. */
1194 build_adjust_context(p, tmp);
1195
1196 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1197 uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update);
1198 /*
1199 * The in the LWX case we don't want to do the load in the
1200 * delay slot. It cannot issue in the same cycle and may be
1201 * speculative and unneeded.
1202 */
1203 if (use_lwx_insns())
1204 uasm_i_nop(p);
1205 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
1206
1207
1208 /* build_update_entries */
1209 if (use_lwx_insns()) {
1210 even = ptr;
1211 odd = tmp;
1212 UASM_i_LWX(p, even, scratch, tmp);
1213 UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t));
1214 UASM_i_LWX(p, odd, scratch, tmp);
1215 } else {
1216 UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */
1217 even = tmp;
1218 odd = ptr;
1219 UASM_i_LW(p, even, 0, ptr); /* get even pte */
1220 UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */
1221 }
1222 if (cpu_has_rixi) {
1223 uasm_i_drotr(p, even, even, ilog2(_PAGE_GLOBAL));
1224 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1225 uasm_i_drotr(p, odd, odd, ilog2(_PAGE_GLOBAL));
1226 } else {
1227 uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL));
1228 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1229 uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL));
1230 }
1231 UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
1232
1233 if (c0_scratch_reg >= 0) {
1234 uasm_i_ehb(p);
1235 UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1236 build_tlb_write_entry(p, l, r, tlb_random);
1237 uasm_l_leave(l, *p);
1238 rv.restore_scratch = 1;
1239 } else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) {
1240 build_tlb_write_entry(p, l, r, tlb_random);
1241 uasm_l_leave(l, *p);
1242 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1243 } else {
1244 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1245 build_tlb_write_entry(p, l, r, tlb_random);
1246 uasm_l_leave(l, *p);
1247 rv.restore_scratch = 1;
1248 }
1249
1250 uasm_i_eret(p); /* return from trap */
1251
1252 return rv;
1253 }
1254
1255 /*
1256 * For a 64-bit kernel, we are using the 64-bit XTLB refill exception
1257 * because EXL == 0. If we wrap, we can also use the 32 instruction
1258 * slots before the XTLB refill exception handler which belong to the
1259 * unused TLB refill exception.
1260 */
1261 #define MIPS64_REFILL_INSNS 32
1262
build_r4000_tlb_refill_handler(void)1263 static void build_r4000_tlb_refill_handler(void)
1264 {
1265 u32 *p = tlb_handler;
1266 struct uasm_label *l = labels;
1267 struct uasm_reloc *r = relocs;
1268 u32 *f;
1269 unsigned int final_len;
1270 struct mips_huge_tlb_info htlb_info __maybe_unused;
1271 enum vmalloc64_mode vmalloc_mode __maybe_unused;
1272
1273 memset(tlb_handler, 0, sizeof(tlb_handler));
1274 memset(labels, 0, sizeof(labels));
1275 memset(relocs, 0, sizeof(relocs));
1276 memset(final_handler, 0, sizeof(final_handler));
1277
1278 if (IS_ENABLED(CONFIG_64BIT) && (scratch_reg >= 0 || scratchpad_available()) && use_bbit_insns()) {
1279 htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1,
1280 scratch_reg);
1281 vmalloc_mode = refill_scratch;
1282 } else {
1283 htlb_info.huge_pte = K0;
1284 htlb_info.restore_scratch = 0;
1285 htlb_info.need_reload_pte = true;
1286 vmalloc_mode = refill_noscratch;
1287 /*
1288 * create the plain linear handler
1289 */
1290 if (bcm1250_m3_war()) {
1291 unsigned int segbits = 44;
1292
1293 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1294 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
1295 uasm_i_xor(&p, K0, K0, K1);
1296 uasm_i_dsrl_safe(&p, K1, K0, 62);
1297 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
1298 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
1299 uasm_i_or(&p, K0, K0, K1);
1300 uasm_il_bnez(&p, &r, K0, label_leave);
1301 /* No need for uasm_i_nop */
1302 }
1303
1304 #ifdef CONFIG_64BIT
1305 build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
1306 #else
1307 build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
1308 #endif
1309
1310 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1311 build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
1312 #endif
1313
1314 build_get_ptep(&p, K0, K1);
1315 build_update_entries(&p, K0, K1);
1316 build_tlb_write_entry(&p, &l, &r, tlb_random);
1317 uasm_l_leave(&l, p);
1318 uasm_i_eret(&p); /* return from trap */
1319 }
1320 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1321 uasm_l_tlb_huge_update(&l, p);
1322 if (htlb_info.need_reload_pte)
1323 UASM_i_LW(&p, htlb_info.huge_pte, 0, K1);
1324 build_huge_update_entries(&p, htlb_info.huge_pte, K1);
1325 build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
1326 htlb_info.restore_scratch);
1327 #endif
1328
1329 #ifdef CONFIG_64BIT
1330 build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode);
1331 #endif
1332
1333 /*
1334 * Overflow check: For the 64bit handler, we need at least one
1335 * free instruction slot for the wrap-around branch. In worst
1336 * case, if the intended insertion point is a delay slot, we
1337 * need three, with the second nop'ed and the third being
1338 * unused.
1339 */
1340 switch (boot_cpu_type()) {
1341 default:
1342 if (sizeof(long) == 4) {
1343 fallthrough;
1344 case CPU_LOONGSON2EF:
1345 /* Loongson2 ebase is different than r4k, we have more space */
1346 if ((p - tlb_handler) > 64)
1347 panic("TLB refill handler space exceeded");
1348 /*
1349 * Now fold the handler in the TLB refill handler space.
1350 */
1351 f = final_handler;
1352 /* Simplest case, just copy the handler. */
1353 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1354 final_len = p - tlb_handler;
1355 break;
1356 } else {
1357 if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
1358 || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
1359 && uasm_insn_has_bdelay(relocs,
1360 tlb_handler + MIPS64_REFILL_INSNS - 3)))
1361 panic("TLB refill handler space exceeded");
1362 /*
1363 * Now fold the handler in the TLB refill handler space.
1364 */
1365 f = final_handler + MIPS64_REFILL_INSNS;
1366 if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
1367 /* Just copy the handler. */
1368 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1369 final_len = p - tlb_handler;
1370 } else {
1371 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1372 const enum label_id ls = label_tlb_huge_update;
1373 #else
1374 const enum label_id ls = label_vmalloc;
1375 #endif
1376 u32 *split;
1377 int ov = 0;
1378 int i;
1379
1380 for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
1381 ;
1382 BUG_ON(i == ARRAY_SIZE(labels));
1383 split = labels[i].addr;
1384
1385 /*
1386 * See if we have overflown one way or the other.
1387 */
1388 if (split > tlb_handler + MIPS64_REFILL_INSNS ||
1389 split < p - MIPS64_REFILL_INSNS)
1390 ov = 1;
1391
1392 if (ov) {
1393 /*
1394 * Split two instructions before the end. One
1395 * for the branch and one for the instruction
1396 * in the delay slot.
1397 */
1398 split = tlb_handler + MIPS64_REFILL_INSNS - 2;
1399
1400 /*
1401 * If the branch would fall in a delay slot,
1402 * we must back up an additional instruction
1403 * so that it is no longer in a delay slot.
1404 */
1405 if (uasm_insn_has_bdelay(relocs, split - 1))
1406 split--;
1407 }
1408 /* Copy first part of the handler. */
1409 uasm_copy_handler(relocs, labels, tlb_handler, split, f);
1410 f += split - tlb_handler;
1411
1412 if (ov) {
1413 /* Insert branch. */
1414 uasm_l_split(&l, final_handler);
1415 uasm_il_b(&f, &r, label_split);
1416 if (uasm_insn_has_bdelay(relocs, split))
1417 uasm_i_nop(&f);
1418 else {
1419 uasm_copy_handler(relocs, labels,
1420 split, split + 1, f);
1421 uasm_move_labels(labels, f, f + 1, -1);
1422 f++;
1423 split++;
1424 }
1425 }
1426
1427 /* Copy the rest of the handler. */
1428 uasm_copy_handler(relocs, labels, split, p, final_handler);
1429 final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
1430 (p - split);
1431 }
1432 }
1433 break;
1434 }
1435
1436 uasm_resolve_relocs(relocs, labels);
1437 pr_debug("Wrote TLB refill handler (%u instructions).\n",
1438 final_len);
1439
1440 memcpy((void *)ebase, final_handler, 0x100);
1441 local_flush_icache_range(ebase, ebase + 0x100);
1442 dump_handler("r4000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x100));
1443 }
1444
setup_pw(void)1445 static void setup_pw(void)
1446 {
1447 unsigned int pwctl;
1448 unsigned long pgd_i, pgd_w;
1449 #ifndef __PAGETABLE_PMD_FOLDED
1450 unsigned long pmd_i, pmd_w;
1451 #endif
1452 unsigned long pt_i, pt_w;
1453 unsigned long pte_i, pte_w;
1454 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1455 unsigned long psn;
1456
1457 psn = ilog2(_PAGE_HUGE); /* bit used to indicate huge page */
1458 #endif
1459 pgd_i = PGDIR_SHIFT; /* 1st level PGD */
1460 #ifndef __PAGETABLE_PMD_FOLDED
1461 pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_TABLE_ORDER;
1462
1463 pmd_i = PMD_SHIFT; /* 2nd level PMD */
1464 pmd_w = PMD_SHIFT - PAGE_SHIFT;
1465 #else
1466 pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_TABLE_ORDER;
1467 #endif
1468
1469 pt_i = PAGE_SHIFT; /* 3rd level PTE */
1470 pt_w = PAGE_SHIFT - 3;
1471
1472 pte_i = ilog2(_PAGE_GLOBAL);
1473 pte_w = 0;
1474 pwctl = 1 << 30; /* Set PWDirExt */
1475
1476 #ifndef __PAGETABLE_PMD_FOLDED
1477 write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i);
1478 write_c0_pwsize(1 << 30 | pgd_w << 24 | pmd_w << 12 | pt_w << 6 | pte_w);
1479 #else
1480 write_c0_pwfield(pgd_i << 24 | pt_i << 6 | pte_i);
1481 write_c0_pwsize(1 << 30 | pgd_w << 24 | pt_w << 6 | pte_w);
1482 #endif
1483
1484 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1485 pwctl |= (1 << 6 | psn);
1486 #endif
1487 write_c0_pwctl(pwctl);
1488 write_c0_kpgd((long)swapper_pg_dir);
1489 kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */
1490 }
1491
build_loongson3_tlb_refill_handler(void)1492 static void build_loongson3_tlb_refill_handler(void)
1493 {
1494 u32 *p = tlb_handler;
1495 struct uasm_label *l = labels;
1496 struct uasm_reloc *r = relocs;
1497
1498 memset(labels, 0, sizeof(labels));
1499 memset(relocs, 0, sizeof(relocs));
1500 memset(tlb_handler, 0, sizeof(tlb_handler));
1501
1502 if (check_for_high_segbits) {
1503 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1504 uasm_i_dsrl_safe(&p, K1, K0, PGDIR_SHIFT + PGD_TABLE_ORDER + PAGE_SHIFT - 3);
1505 uasm_il_beqz(&p, &r, K1, label_vmalloc);
1506 uasm_i_nop(&p);
1507
1508 uasm_il_bgez(&p, &r, K0, label_large_segbits_fault);
1509 uasm_i_nop(&p);
1510 uasm_l_vmalloc(&l, p);
1511 }
1512
1513 uasm_i_dmfc0(&p, K1, C0_PGD);
1514
1515 uasm_i_lddir(&p, K0, K1, 3); /* global page dir */
1516 #ifndef __PAGETABLE_PMD_FOLDED
1517 uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */
1518 #endif
1519 uasm_i_ldpte(&p, K1, 0); /* even */
1520 uasm_i_ldpte(&p, K1, 1); /* odd */
1521 uasm_i_tlbwr(&p);
1522
1523 /* restore page mask */
1524 if (PM_DEFAULT_MASK >> 16) {
1525 uasm_i_lui(&p, K0, PM_DEFAULT_MASK >> 16);
1526 uasm_i_ori(&p, K0, K0, PM_DEFAULT_MASK & 0xffff);
1527 uasm_i_mtc0(&p, K0, C0_PAGEMASK);
1528 } else if (PM_DEFAULT_MASK) {
1529 uasm_i_ori(&p, K0, 0, PM_DEFAULT_MASK);
1530 uasm_i_mtc0(&p, K0, C0_PAGEMASK);
1531 } else {
1532 uasm_i_mtc0(&p, 0, C0_PAGEMASK);
1533 }
1534
1535 uasm_i_eret(&p);
1536
1537 if (check_for_high_segbits) {
1538 uasm_l_large_segbits_fault(&l, p);
1539 UASM_i_LA(&p, K1, (unsigned long)tlb_do_page_fault_0);
1540 uasm_i_jr(&p, K1);
1541 uasm_i_nop(&p);
1542 }
1543
1544 uasm_resolve_relocs(relocs, labels);
1545 memcpy((void *)(ebase + 0x80), tlb_handler, 0x80);
1546 local_flush_icache_range(ebase + 0x80, ebase + 0x100);
1547 dump_handler("loongson3_tlb_refill",
1548 (u32 *)(ebase + 0x80), (u32 *)(ebase + 0x100));
1549 }
1550
build_setup_pgd(void)1551 static void build_setup_pgd(void)
1552 {
1553 const int a0 = 4;
1554 const int __maybe_unused a1 = 5;
1555 const int __maybe_unused a2 = 6;
1556 u32 *p = (u32 *)msk_isa16_mode((ulong)tlbmiss_handler_setup_pgd);
1557 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1558 long pgdc = (long)pgd_current;
1559 #endif
1560
1561 memset(p, 0, tlbmiss_handler_setup_pgd_end - (char *)p);
1562 memset(labels, 0, sizeof(labels));
1563 memset(relocs, 0, sizeof(relocs));
1564 pgd_reg = allocate_kscratch();
1565 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
1566 if (pgd_reg == -1) {
1567 struct uasm_label *l = labels;
1568 struct uasm_reloc *r = relocs;
1569
1570 /* PGD << 11 in c0_Context */
1571 /*
1572 * If it is a ckseg0 address, convert to a physical
1573 * address. Shifting right by 29 and adding 4 will
1574 * result in zero for these addresses.
1575 *
1576 */
1577 UASM_i_SRA(&p, a1, a0, 29);
1578 UASM_i_ADDIU(&p, a1, a1, 4);
1579 uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1);
1580 uasm_i_nop(&p);
1581 uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
1582 uasm_l_tlbl_goaround1(&l, p);
1583 UASM_i_SLL(&p, a0, a0, 11);
1584 UASM_i_MTC0(&p, a0, C0_CONTEXT);
1585 uasm_i_jr(&p, 31);
1586 uasm_i_ehb(&p);
1587 } else {
1588 /* PGD in c0_KScratch */
1589 if (cpu_has_ldpte)
1590 UASM_i_MTC0(&p, a0, C0_PWBASE);
1591 else
1592 UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
1593 uasm_i_jr(&p, 31);
1594 uasm_i_ehb(&p);
1595 }
1596 #else
1597 #ifdef CONFIG_SMP
1598 /* Save PGD to pgd_current[smp_processor_id()] */
1599 UASM_i_CPUID_MFC0(&p, a1, SMP_CPUID_REG);
1600 UASM_i_SRL_SAFE(&p, a1, a1, SMP_CPUID_PTRSHIFT);
1601 UASM_i_LA_mostly(&p, a2, pgdc);
1602 UASM_i_ADDU(&p, a2, a2, a1);
1603 UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
1604 #else
1605 UASM_i_LA_mostly(&p, a2, pgdc);
1606 UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
1607 #endif /* SMP */
1608
1609 /* if pgd_reg is allocated, save PGD also to scratch register */
1610 if (pgd_reg != -1) {
1611 UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
1612 uasm_i_jr(&p, 31);
1613 uasm_i_ehb(&p);
1614 } else {
1615 uasm_i_jr(&p, 31);
1616 uasm_i_nop(&p);
1617 }
1618 #endif
1619 if (p >= (u32 *)tlbmiss_handler_setup_pgd_end)
1620 panic("tlbmiss_handler_setup_pgd space exceeded");
1621
1622 uasm_resolve_relocs(relocs, labels);
1623 pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n",
1624 (unsigned int)(p - (u32 *)tlbmiss_handler_setup_pgd));
1625
1626 dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd,
1627 tlbmiss_handler_setup_pgd_end);
1628 }
1629
1630 static void
iPTE_LW(u32 ** p,unsigned int pte,unsigned int ptr)1631 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
1632 {
1633 #ifdef CONFIG_SMP
1634 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
1635 uasm_i_sync(p, 0);
1636 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1637 if (cpu_has_64bits)
1638 uasm_i_lld(p, pte, 0, ptr);
1639 else
1640 # endif
1641 UASM_i_LL(p, pte, 0, ptr);
1642 #else
1643 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1644 if (cpu_has_64bits)
1645 uasm_i_ld(p, pte, 0, ptr);
1646 else
1647 # endif
1648 UASM_i_LW(p, pte, 0, ptr);
1649 #endif
1650 }
1651
1652 static void
iPTE_SW(u32 ** p,struct uasm_reloc ** r,unsigned int pte,unsigned int ptr,unsigned int mode,unsigned int scratch)1653 iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
1654 unsigned int mode, unsigned int scratch)
1655 {
1656 unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
1657 unsigned int swmode = mode & ~hwmode;
1658
1659 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_64bits) {
1660 uasm_i_lui(p, scratch, swmode >> 16);
1661 uasm_i_or(p, pte, pte, scratch);
1662 BUG_ON(swmode & 0xffff);
1663 } else {
1664 uasm_i_ori(p, pte, pte, mode);
1665 }
1666
1667 #ifdef CONFIG_SMP
1668 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1669 if (cpu_has_64bits)
1670 uasm_i_scd(p, pte, 0, ptr);
1671 else
1672 # endif
1673 UASM_i_SC(p, pte, 0, ptr);
1674
1675 if (r10000_llsc_war())
1676 uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
1677 else
1678 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1679
1680 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1681 if (!cpu_has_64bits) {
1682 /* no uasm_i_nop needed */
1683 uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
1684 uasm_i_ori(p, pte, pte, hwmode);
1685 BUG_ON(hwmode & ~0xffff);
1686 uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
1687 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1688 /* no uasm_i_nop needed */
1689 uasm_i_lw(p, pte, 0, ptr);
1690 } else
1691 uasm_i_nop(p);
1692 # else
1693 uasm_i_nop(p);
1694 # endif
1695 #else
1696 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1697 if (cpu_has_64bits)
1698 uasm_i_sd(p, pte, 0, ptr);
1699 else
1700 # endif
1701 UASM_i_SW(p, pte, 0, ptr);
1702
1703 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1704 if (!cpu_has_64bits) {
1705 uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
1706 uasm_i_ori(p, pte, pte, hwmode);
1707 BUG_ON(hwmode & ~0xffff);
1708 uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
1709 uasm_i_lw(p, pte, 0, ptr);
1710 }
1711 # endif
1712 #endif
1713 }
1714
1715 /*
1716 * Check if PTE is present, if not then jump to LABEL. PTR points to
1717 * the page table where this PTE is located, PTE will be re-loaded
1718 * with it's original value.
1719 */
1720 static void
build_pte_present(u32 ** p,struct uasm_reloc ** r,int pte,int ptr,int scratch,enum label_id lid)1721 build_pte_present(u32 **p, struct uasm_reloc **r,
1722 int pte, int ptr, int scratch, enum label_id lid)
1723 {
1724 int t = scratch >= 0 ? scratch : pte;
1725 int cur = pte;
1726
1727 if (cpu_has_rixi) {
1728 if (use_bbit_insns()) {
1729 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
1730 uasm_i_nop(p);
1731 } else {
1732 if (_PAGE_PRESENT_SHIFT) {
1733 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1734 cur = t;
1735 }
1736 uasm_i_andi(p, t, cur, 1);
1737 uasm_il_beqz(p, r, t, lid);
1738 if (pte == t)
1739 /* You lose the SMP race :-(*/
1740 iPTE_LW(p, pte, ptr);
1741 }
1742 } else {
1743 if (_PAGE_PRESENT_SHIFT) {
1744 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1745 cur = t;
1746 }
1747 uasm_i_andi(p, t, cur,
1748 (_PAGE_PRESENT | _PAGE_NO_READ) >> _PAGE_PRESENT_SHIFT);
1749 uasm_i_xori(p, t, t, _PAGE_PRESENT >> _PAGE_PRESENT_SHIFT);
1750 uasm_il_bnez(p, r, t, lid);
1751 if (pte == t)
1752 /* You lose the SMP race :-(*/
1753 iPTE_LW(p, pte, ptr);
1754 }
1755 }
1756
1757 /* Make PTE valid, store result in PTR. */
1758 static void
build_make_valid(u32 ** p,struct uasm_reloc ** r,unsigned int pte,unsigned int ptr,unsigned int scratch)1759 build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
1760 unsigned int ptr, unsigned int scratch)
1761 {
1762 unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
1763
1764 iPTE_SW(p, r, pte, ptr, mode, scratch);
1765 }
1766
1767 /*
1768 * Check if PTE can be written to, if not branch to LABEL. Regardless
1769 * restore PTE with value from PTR when done.
1770 */
1771 static void
build_pte_writable(u32 ** p,struct uasm_reloc ** r,unsigned int pte,unsigned int ptr,int scratch,enum label_id lid)1772 build_pte_writable(u32 **p, struct uasm_reloc **r,
1773 unsigned int pte, unsigned int ptr, int scratch,
1774 enum label_id lid)
1775 {
1776 int t = scratch >= 0 ? scratch : pte;
1777 int cur = pte;
1778
1779 if (_PAGE_PRESENT_SHIFT) {
1780 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1781 cur = t;
1782 }
1783 uasm_i_andi(p, t, cur,
1784 (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
1785 uasm_i_xori(p, t, t,
1786 (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
1787 uasm_il_bnez(p, r, t, lid);
1788 if (pte == t)
1789 /* You lose the SMP race :-(*/
1790 iPTE_LW(p, pte, ptr);
1791 else
1792 uasm_i_nop(p);
1793 }
1794
1795 /* Make PTE writable, update software status bits as well, then store
1796 * at PTR.
1797 */
1798 static void
build_make_write(u32 ** p,struct uasm_reloc ** r,unsigned int pte,unsigned int ptr,unsigned int scratch)1799 build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
1800 unsigned int ptr, unsigned int scratch)
1801 {
1802 unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1803 | _PAGE_DIRTY);
1804
1805 iPTE_SW(p, r, pte, ptr, mode, scratch);
1806 }
1807
1808 /*
1809 * Check if PTE can be modified, if not branch to LABEL. Regardless
1810 * restore PTE with value from PTR when done.
1811 */
1812 static void
build_pte_modifiable(u32 ** p,struct uasm_reloc ** r,unsigned int pte,unsigned int ptr,int scratch,enum label_id lid)1813 build_pte_modifiable(u32 **p, struct uasm_reloc **r,
1814 unsigned int pte, unsigned int ptr, int scratch,
1815 enum label_id lid)
1816 {
1817 if (use_bbit_insns()) {
1818 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_WRITE), lid);
1819 uasm_i_nop(p);
1820 } else {
1821 int t = scratch >= 0 ? scratch : pte;
1822 uasm_i_srl(p, t, pte, _PAGE_WRITE_SHIFT);
1823 uasm_i_andi(p, t, t, 1);
1824 uasm_il_beqz(p, r, t, lid);
1825 if (pte == t)
1826 /* You lose the SMP race :-(*/
1827 iPTE_LW(p, pte, ptr);
1828 }
1829 }
1830
1831 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1832
1833
1834 /*
1835 * R3000 style TLB load/store/modify handlers.
1836 */
1837
1838 /*
1839 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1840 * Then it returns.
1841 */
1842 static void
build_r3000_pte_reload_tlbwi(u32 ** p,unsigned int pte,unsigned int tmp)1843 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1844 {
1845 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1846 uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1847 uasm_i_tlbwi(p);
1848 uasm_i_jr(p, tmp);
1849 uasm_i_rfe(p); /* branch delay */
1850 }
1851
1852 /*
1853 * This places the pte into ENTRYLO0 and writes it with tlbwi
1854 * or tlbwr as appropriate. This is because the index register
1855 * may have the probe fail bit set as a result of a trap on a
1856 * kseg2 access, i.e. without refill. Then it returns.
1857 */
1858 static void
build_r3000_tlb_reload_write(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,unsigned int pte,unsigned int tmp)1859 build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
1860 struct uasm_reloc **r, unsigned int pte,
1861 unsigned int tmp)
1862 {
1863 uasm_i_mfc0(p, tmp, C0_INDEX);
1864 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1865 uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1866 uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
1867 uasm_i_tlbwi(p); /* cp0 delay */
1868 uasm_i_jr(p, tmp);
1869 uasm_i_rfe(p); /* branch delay */
1870 uasm_l_r3000_write_probe_fail(l, *p);
1871 uasm_i_tlbwr(p); /* cp0 delay */
1872 uasm_i_jr(p, tmp);
1873 uasm_i_rfe(p); /* branch delay */
1874 }
1875
1876 static void
build_r3000_tlbchange_handler_head(u32 ** p,unsigned int pte,unsigned int ptr)1877 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1878 unsigned int ptr)
1879 {
1880 long pgdc = (long)pgd_current;
1881
1882 uasm_i_mfc0(p, pte, C0_BADVADDR);
1883 uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
1884 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
1885 uasm_i_srl(p, pte, pte, 22); /* load delay */
1886 uasm_i_sll(p, pte, pte, 2);
1887 uasm_i_addu(p, ptr, ptr, pte);
1888 uasm_i_mfc0(p, pte, C0_CONTEXT);
1889 uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
1890 uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
1891 uasm_i_addu(p, ptr, ptr, pte);
1892 uasm_i_lw(p, pte, 0, ptr);
1893 uasm_i_tlbp(p); /* load delay */
1894 }
1895
build_r3000_tlb_load_handler(void)1896 static void build_r3000_tlb_load_handler(void)
1897 {
1898 u32 *p = (u32 *)handle_tlbl;
1899 struct uasm_label *l = labels;
1900 struct uasm_reloc *r = relocs;
1901
1902 memset(p, 0, handle_tlbl_end - (char *)p);
1903 memset(labels, 0, sizeof(labels));
1904 memset(relocs, 0, sizeof(relocs));
1905
1906 build_r3000_tlbchange_handler_head(&p, K0, K1);
1907 build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl);
1908 uasm_i_nop(&p); /* load delay */
1909 build_make_valid(&p, &r, K0, K1, -1);
1910 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1911
1912 uasm_l_nopage_tlbl(&l, p);
1913 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1914 uasm_i_nop(&p);
1915
1916 if (p >= (u32 *)handle_tlbl_end)
1917 panic("TLB load handler fastpath space exceeded");
1918
1919 uasm_resolve_relocs(relocs, labels);
1920 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1921 (unsigned int)(p - (u32 *)handle_tlbl));
1922
1923 dump_handler("r3000_tlb_load", handle_tlbl, handle_tlbl_end);
1924 }
1925
build_r3000_tlb_store_handler(void)1926 static void build_r3000_tlb_store_handler(void)
1927 {
1928 u32 *p = (u32 *)handle_tlbs;
1929 struct uasm_label *l = labels;
1930 struct uasm_reloc *r = relocs;
1931
1932 memset(p, 0, handle_tlbs_end - (char *)p);
1933 memset(labels, 0, sizeof(labels));
1934 memset(relocs, 0, sizeof(relocs));
1935
1936 build_r3000_tlbchange_handler_head(&p, K0, K1);
1937 build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs);
1938 uasm_i_nop(&p); /* load delay */
1939 build_make_write(&p, &r, K0, K1, -1);
1940 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1941
1942 uasm_l_nopage_tlbs(&l, p);
1943 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1944 uasm_i_nop(&p);
1945
1946 if (p >= (u32 *)handle_tlbs_end)
1947 panic("TLB store handler fastpath space exceeded");
1948
1949 uasm_resolve_relocs(relocs, labels);
1950 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1951 (unsigned int)(p - (u32 *)handle_tlbs));
1952
1953 dump_handler("r3000_tlb_store", handle_tlbs, handle_tlbs_end);
1954 }
1955
build_r3000_tlb_modify_handler(void)1956 static void build_r3000_tlb_modify_handler(void)
1957 {
1958 u32 *p = (u32 *)handle_tlbm;
1959 struct uasm_label *l = labels;
1960 struct uasm_reloc *r = relocs;
1961
1962 memset(p, 0, handle_tlbm_end - (char *)p);
1963 memset(labels, 0, sizeof(labels));
1964 memset(relocs, 0, sizeof(relocs));
1965
1966 build_r3000_tlbchange_handler_head(&p, K0, K1);
1967 build_pte_modifiable(&p, &r, K0, K1, -1, label_nopage_tlbm);
1968 uasm_i_nop(&p); /* load delay */
1969 build_make_write(&p, &r, K0, K1, -1);
1970 build_r3000_pte_reload_tlbwi(&p, K0, K1);
1971
1972 uasm_l_nopage_tlbm(&l, p);
1973 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1974 uasm_i_nop(&p);
1975
1976 if (p >= (u32 *)handle_tlbm_end)
1977 panic("TLB modify handler fastpath space exceeded");
1978
1979 uasm_resolve_relocs(relocs, labels);
1980 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1981 (unsigned int)(p - (u32 *)handle_tlbm));
1982
1983 dump_handler("r3000_tlb_modify", handle_tlbm, handle_tlbm_end);
1984 }
1985 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
1986
cpu_has_tlbex_tlbp_race(void)1987 static bool cpu_has_tlbex_tlbp_race(void)
1988 {
1989 /*
1990 * When a Hardware Table Walker is running it can replace TLB entries
1991 * at any time, leading to a race between it & the CPU.
1992 */
1993 if (cpu_has_htw)
1994 return true;
1995
1996 /*
1997 * If the CPU shares FTLB RAM with its siblings then our entry may be
1998 * replaced at any time by a sibling performing a write to the FTLB.
1999 */
2000 if (cpu_has_shared_ftlb_ram)
2001 return true;
2002
2003 /* In all other cases there ought to be no race condition to handle */
2004 return false;
2005 }
2006
2007 /*
2008 * R4000 style TLB load/store/modify handlers.
2009 */
2010 static struct work_registers
build_r4000_tlbchange_handler_head(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r)2011 build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
2012 struct uasm_reloc **r)
2013 {
2014 struct work_registers wr = build_get_work_registers(p);
2015
2016 #ifdef CONFIG_64BIT
2017 build_get_pmde64(p, l, r, wr.r1, wr.r2); /* get pmd in ptr */
2018 #else
2019 build_get_pgde32(p, wr.r1, wr.r2); /* get pgd in ptr */
2020 #endif
2021
2022 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2023 /*
2024 * For huge tlb entries, pmd doesn't contain an address but
2025 * instead contains the tlb pte. Check the PAGE_HUGE bit and
2026 * see if we need to jump to huge tlb processing.
2027 */
2028 build_is_huge_pte(p, r, wr.r1, wr.r2, label_tlb_huge_update);
2029 #endif
2030
2031 UASM_i_MFC0(p, wr.r1, C0_BADVADDR);
2032 UASM_i_LW(p, wr.r2, 0, wr.r2);
2033 UASM_i_SRL(p, wr.r1, wr.r1, PAGE_SHIFT - PTE_T_LOG2);
2034 uasm_i_andi(p, wr.r1, wr.r1, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
2035 UASM_i_ADDU(p, wr.r2, wr.r2, wr.r1);
2036
2037 #ifdef CONFIG_SMP
2038 uasm_l_smp_pgtable_change(l, *p);
2039 #endif
2040 iPTE_LW(p, wr.r1, wr.r2); /* get even pte */
2041 if (!m4kc_tlbp_war()) {
2042 build_tlb_probe_entry(p);
2043 if (cpu_has_tlbex_tlbp_race()) {
2044 /* race condition happens, leaving */
2045 uasm_i_ehb(p);
2046 uasm_i_mfc0(p, wr.r3, C0_INDEX);
2047 uasm_il_bltz(p, r, wr.r3, label_leave);
2048 uasm_i_nop(p);
2049 }
2050 }
2051 return wr;
2052 }
2053
2054 static void
build_r4000_tlbchange_handler_tail(u32 ** p,struct uasm_label ** l,struct uasm_reloc ** r,unsigned int tmp,unsigned int ptr)2055 build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
2056 struct uasm_reloc **r, unsigned int tmp,
2057 unsigned int ptr)
2058 {
2059 uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
2060 uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
2061 build_update_entries(p, tmp, ptr);
2062 build_tlb_write_entry(p, l, r, tlb_indexed);
2063 uasm_l_leave(l, *p);
2064 build_restore_work_registers(p);
2065 uasm_i_eret(p); /* return from trap */
2066
2067 #ifdef CONFIG_64BIT
2068 build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill);
2069 #endif
2070 }
2071
build_r4000_tlb_load_handler(void)2072 static void build_r4000_tlb_load_handler(void)
2073 {
2074 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl);
2075 struct uasm_label *l = labels;
2076 struct uasm_reloc *r = relocs;
2077 struct work_registers wr;
2078
2079 memset(p, 0, handle_tlbl_end - (char *)p);
2080 memset(labels, 0, sizeof(labels));
2081 memset(relocs, 0, sizeof(relocs));
2082
2083 if (bcm1250_m3_war()) {
2084 unsigned int segbits = 44;
2085
2086 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
2087 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
2088 uasm_i_xor(&p, K0, K0, K1);
2089 uasm_i_dsrl_safe(&p, K1, K0, 62);
2090 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
2091 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
2092 uasm_i_or(&p, K0, K0, K1);
2093 uasm_il_bnez(&p, &r, K0, label_leave);
2094 /* No need for uasm_i_nop */
2095 }
2096
2097 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2098 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
2099 if (m4kc_tlbp_war())
2100 build_tlb_probe_entry(&p);
2101
2102 if (cpu_has_rixi && !cpu_has_rixiex) {
2103 /*
2104 * If the page is not _PAGE_VALID, RI or XI could not
2105 * have triggered it. Skip the expensive test..
2106 */
2107 if (use_bbit_insns()) {
2108 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
2109 label_tlbl_goaround1);
2110 } else {
2111 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
2112 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1);
2113 }
2114 uasm_i_nop(&p);
2115
2116 /*
2117 * Warn if something may race with us & replace the TLB entry
2118 * before we read it here. Everything with such races should
2119 * also have dedicated RiXi exception handlers, so this
2120 * shouldn't be hit.
2121 */
2122 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
2123
2124 uasm_i_tlbr(&p);
2125
2126 switch (current_cpu_type()) {
2127 case CPU_CAVIUM_OCTEON:
2128 case CPU_CAVIUM_OCTEON_PLUS:
2129 case CPU_CAVIUM_OCTEON2:
2130 break;
2131 default:
2132 if (cpu_has_mips_r2_exec_hazard)
2133 uasm_i_ehb(&p);
2134 break;
2135 }
2136
2137 /* Examine entrylo 0 or 1 based on ptr. */
2138 if (use_bbit_insns()) {
2139 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
2140 } else {
2141 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
2142 uasm_i_beqz(&p, wr.r3, 8);
2143 }
2144 /* load it in the delay slot*/
2145 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
2146 /* load it if ptr is odd */
2147 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
2148 /*
2149 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
2150 * XI must have triggered it.
2151 */
2152 if (use_bbit_insns()) {
2153 uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl);
2154 uasm_i_nop(&p);
2155 uasm_l_tlbl_goaround1(&l, p);
2156 } else {
2157 uasm_i_andi(&p, wr.r3, wr.r3, 2);
2158 uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl);
2159 uasm_i_nop(&p);
2160 }
2161 uasm_l_tlbl_goaround1(&l, p);
2162 }
2163 build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3);
2164 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2165
2166 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2167 /*
2168 * This is the entry point when build_r4000_tlbchange_handler_head
2169 * spots a huge page.
2170 */
2171 uasm_l_tlb_huge_update(&l, p);
2172 iPTE_LW(&p, wr.r1, wr.r2);
2173 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
2174 build_tlb_probe_entry(&p);
2175
2176 if (cpu_has_rixi && !cpu_has_rixiex) {
2177 /*
2178 * If the page is not _PAGE_VALID, RI or XI could not
2179 * have triggered it. Skip the expensive test..
2180 */
2181 if (use_bbit_insns()) {
2182 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
2183 label_tlbl_goaround2);
2184 } else {
2185 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
2186 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
2187 }
2188 uasm_i_nop(&p);
2189
2190 /*
2191 * Warn if something may race with us & replace the TLB entry
2192 * before we read it here. Everything with such races should
2193 * also have dedicated RiXi exception handlers, so this
2194 * shouldn't be hit.
2195 */
2196 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
2197
2198 uasm_i_tlbr(&p);
2199
2200 switch (current_cpu_type()) {
2201 case CPU_CAVIUM_OCTEON:
2202 case CPU_CAVIUM_OCTEON_PLUS:
2203 case CPU_CAVIUM_OCTEON2:
2204 break;
2205 default:
2206 if (cpu_has_mips_r2_exec_hazard)
2207 uasm_i_ehb(&p);
2208 break;
2209 }
2210
2211 /* Examine entrylo 0 or 1 based on ptr. */
2212 if (use_bbit_insns()) {
2213 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
2214 } else {
2215 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
2216 uasm_i_beqz(&p, wr.r3, 8);
2217 }
2218 /* load it in the delay slot*/
2219 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
2220 /* load it if ptr is odd */
2221 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
2222 /*
2223 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
2224 * XI must have triggered it.
2225 */
2226 if (use_bbit_insns()) {
2227 uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2);
2228 } else {
2229 uasm_i_andi(&p, wr.r3, wr.r3, 2);
2230 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
2231 }
2232 if (PM_DEFAULT_MASK == 0)
2233 uasm_i_nop(&p);
2234 /*
2235 * We clobbered C0_PAGEMASK, restore it. On the other branch
2236 * it is restored in build_huge_tlb_write_entry.
2237 */
2238 build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0);
2239
2240 uasm_l_tlbl_goaround2(&l, p);
2241 }
2242 uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID));
2243 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
2244 #endif
2245
2246 uasm_l_nopage_tlbl(&l, p);
2247 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
2248 uasm_i_sync(&p, 0);
2249 build_restore_work_registers(&p);
2250 #ifdef CONFIG_CPU_MICROMIPS
2251 if ((unsigned long)tlb_do_page_fault_0 & 1) {
2252 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0));
2253 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0));
2254 uasm_i_jr(&p, K0);
2255 } else
2256 #endif
2257 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
2258 uasm_i_nop(&p);
2259
2260 if (p >= (u32 *)handle_tlbl_end)
2261 panic("TLB load handler fastpath space exceeded");
2262
2263 uasm_resolve_relocs(relocs, labels);
2264 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
2265 (unsigned int)(p - (u32 *)handle_tlbl));
2266
2267 dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_end);
2268 }
2269
build_r4000_tlb_store_handler(void)2270 static void build_r4000_tlb_store_handler(void)
2271 {
2272 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbs);
2273 struct uasm_label *l = labels;
2274 struct uasm_reloc *r = relocs;
2275 struct work_registers wr;
2276
2277 memset(p, 0, handle_tlbs_end - (char *)p);
2278 memset(labels, 0, sizeof(labels));
2279 memset(relocs, 0, sizeof(relocs));
2280
2281 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2282 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2283 if (m4kc_tlbp_war())
2284 build_tlb_probe_entry(&p);
2285 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);
2286 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2287
2288 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2289 /*
2290 * This is the entry point when
2291 * build_r4000_tlbchange_handler_head spots a huge page.
2292 */
2293 uasm_l_tlb_huge_update(&l, p);
2294 iPTE_LW(&p, wr.r1, wr.r2);
2295 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2296 build_tlb_probe_entry(&p);
2297 uasm_i_ori(&p, wr.r1, wr.r1,
2298 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2299 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
2300 #endif
2301
2302 uasm_l_nopage_tlbs(&l, p);
2303 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
2304 uasm_i_sync(&p, 0);
2305 build_restore_work_registers(&p);
2306 #ifdef CONFIG_CPU_MICROMIPS
2307 if ((unsigned long)tlb_do_page_fault_1 & 1) {
2308 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
2309 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
2310 uasm_i_jr(&p, K0);
2311 } else
2312 #endif
2313 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2314 uasm_i_nop(&p);
2315
2316 if (p >= (u32 *)handle_tlbs_end)
2317 panic("TLB store handler fastpath space exceeded");
2318
2319 uasm_resolve_relocs(relocs, labels);
2320 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
2321 (unsigned int)(p - (u32 *)handle_tlbs));
2322
2323 dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_end);
2324 }
2325
build_r4000_tlb_modify_handler(void)2326 static void build_r4000_tlb_modify_handler(void)
2327 {
2328 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbm);
2329 struct uasm_label *l = labels;
2330 struct uasm_reloc *r = relocs;
2331 struct work_registers wr;
2332
2333 memset(p, 0, handle_tlbm_end - (char *)p);
2334 memset(labels, 0, sizeof(labels));
2335 memset(relocs, 0, sizeof(relocs));
2336
2337 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2338 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2339 if (m4kc_tlbp_war())
2340 build_tlb_probe_entry(&p);
2341 /* Present and writable bits set, set accessed and dirty bits. */
2342 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);
2343 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2344
2345 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2346 /*
2347 * This is the entry point when
2348 * build_r4000_tlbchange_handler_head spots a huge page.
2349 */
2350 uasm_l_tlb_huge_update(&l, p);
2351 iPTE_LW(&p, wr.r1, wr.r2);
2352 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2353 build_tlb_probe_entry(&p);
2354 uasm_i_ori(&p, wr.r1, wr.r1,
2355 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2356 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0);
2357 #endif
2358
2359 uasm_l_nopage_tlbm(&l, p);
2360 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS))
2361 uasm_i_sync(&p, 0);
2362 build_restore_work_registers(&p);
2363 #ifdef CONFIG_CPU_MICROMIPS
2364 if ((unsigned long)tlb_do_page_fault_1 & 1) {
2365 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
2366 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
2367 uasm_i_jr(&p, K0);
2368 } else
2369 #endif
2370 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2371 uasm_i_nop(&p);
2372
2373 if (p >= (u32 *)handle_tlbm_end)
2374 panic("TLB modify handler fastpath space exceeded");
2375
2376 uasm_resolve_relocs(relocs, labels);
2377 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
2378 (unsigned int)(p - (u32 *)handle_tlbm));
2379
2380 dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_end);
2381 }
2382
flush_tlb_handlers(void)2383 static void flush_tlb_handlers(void)
2384 {
2385 local_flush_icache_range((unsigned long)handle_tlbl,
2386 (unsigned long)handle_tlbl_end);
2387 local_flush_icache_range((unsigned long)handle_tlbs,
2388 (unsigned long)handle_tlbs_end);
2389 local_flush_icache_range((unsigned long)handle_tlbm,
2390 (unsigned long)handle_tlbm_end);
2391 local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
2392 (unsigned long)tlbmiss_handler_setup_pgd_end);
2393 }
2394
print_htw_config(void)2395 static void print_htw_config(void)
2396 {
2397 unsigned long config;
2398 unsigned int pwctl;
2399 const int field = 2 * sizeof(unsigned long);
2400
2401 config = read_c0_pwfield();
2402 pr_debug("PWField (0x%0*lx): GDI: 0x%02lx UDI: 0x%02lx MDI: 0x%02lx PTI: 0x%02lx PTEI: 0x%02lx\n",
2403 field, config,
2404 (config & MIPS_PWFIELD_GDI_MASK) >> MIPS_PWFIELD_GDI_SHIFT,
2405 (config & MIPS_PWFIELD_UDI_MASK) >> MIPS_PWFIELD_UDI_SHIFT,
2406 (config & MIPS_PWFIELD_MDI_MASK) >> MIPS_PWFIELD_MDI_SHIFT,
2407 (config & MIPS_PWFIELD_PTI_MASK) >> MIPS_PWFIELD_PTI_SHIFT,
2408 (config & MIPS_PWFIELD_PTEI_MASK) >> MIPS_PWFIELD_PTEI_SHIFT);
2409
2410 config = read_c0_pwsize();
2411 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",
2412 field, config,
2413 (config & MIPS_PWSIZE_PS_MASK) >> MIPS_PWSIZE_PS_SHIFT,
2414 (config & MIPS_PWSIZE_GDW_MASK) >> MIPS_PWSIZE_GDW_SHIFT,
2415 (config & MIPS_PWSIZE_UDW_MASK) >> MIPS_PWSIZE_UDW_SHIFT,
2416 (config & MIPS_PWSIZE_MDW_MASK) >> MIPS_PWSIZE_MDW_SHIFT,
2417 (config & MIPS_PWSIZE_PTW_MASK) >> MIPS_PWSIZE_PTW_SHIFT,
2418 (config & MIPS_PWSIZE_PTEW_MASK) >> MIPS_PWSIZE_PTEW_SHIFT);
2419
2420 pwctl = read_c0_pwctl();
2421 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",
2422 pwctl,
2423 (pwctl & MIPS_PWCTL_PWEN_MASK) >> MIPS_PWCTL_PWEN_SHIFT,
2424 (pwctl & MIPS_PWCTL_XK_MASK) >> MIPS_PWCTL_XK_SHIFT,
2425 (pwctl & MIPS_PWCTL_XS_MASK) >> MIPS_PWCTL_XS_SHIFT,
2426 (pwctl & MIPS_PWCTL_XU_MASK) >> MIPS_PWCTL_XU_SHIFT,
2427 (pwctl & MIPS_PWCTL_DPH_MASK) >> MIPS_PWCTL_DPH_SHIFT,
2428 (pwctl & MIPS_PWCTL_HUGEPG_MASK) >> MIPS_PWCTL_HUGEPG_SHIFT,
2429 (pwctl & MIPS_PWCTL_PSN_MASK) >> MIPS_PWCTL_PSN_SHIFT);
2430 }
2431
config_htw_params(void)2432 static void config_htw_params(void)
2433 {
2434 unsigned long pwfield, pwsize, ptei;
2435 unsigned int config;
2436
2437 /*
2438 * We are using 2-level page tables, so we only need to
2439 * setup GDW and PTW appropriately. UDW and MDW will remain 0.
2440 * The default value of GDI/UDI/MDI/PTI is 0xc. It is illegal to
2441 * write values less than 0xc in these fields because the entire
2442 * write will be dropped. As a result of which, we must preserve
2443 * the original reset values and overwrite only what we really want.
2444 */
2445
2446 pwfield = read_c0_pwfield();
2447 /* re-initialize the GDI field */
2448 pwfield &= ~MIPS_PWFIELD_GDI_MASK;
2449 pwfield |= PGDIR_SHIFT << MIPS_PWFIELD_GDI_SHIFT;
2450 /* re-initialize the PTI field including the even/odd bit */
2451 pwfield &= ~MIPS_PWFIELD_PTI_MASK;
2452 pwfield |= PAGE_SHIFT << MIPS_PWFIELD_PTI_SHIFT;
2453 if (CONFIG_PGTABLE_LEVELS >= 3) {
2454 pwfield &= ~MIPS_PWFIELD_MDI_MASK;
2455 pwfield |= PMD_SHIFT << MIPS_PWFIELD_MDI_SHIFT;
2456 }
2457 /* Set the PTEI right shift */
2458 ptei = _PAGE_GLOBAL_SHIFT << MIPS_PWFIELD_PTEI_SHIFT;
2459 pwfield |= ptei;
2460 write_c0_pwfield(pwfield);
2461 /* Check whether the PTEI value is supported */
2462 back_to_back_c0_hazard();
2463 pwfield = read_c0_pwfield();
2464 if (((pwfield & MIPS_PWFIELD_PTEI_MASK) << MIPS_PWFIELD_PTEI_SHIFT)
2465 != ptei) {
2466 pr_warn("Unsupported PTEI field value: 0x%lx. HTW will not be enabled",
2467 ptei);
2468 /*
2469 * Drop option to avoid HTW being enabled via another path
2470 * (eg htw_reset())
2471 */
2472 current_cpu_data.options &= ~MIPS_CPU_HTW;
2473 return;
2474 }
2475
2476 pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT;
2477 pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT;
2478 if (CONFIG_PGTABLE_LEVELS >= 3)
2479 pwsize |= ilog2(PTRS_PER_PMD) << MIPS_PWSIZE_MDW_SHIFT;
2480
2481 /* Set pointer size to size of directory pointers */
2482 if (IS_ENABLED(CONFIG_64BIT))
2483 pwsize |= MIPS_PWSIZE_PS_MASK;
2484 /* PTEs may be multiple pointers long (e.g. with XPA) */
2485 pwsize |= ((PTE_T_LOG2 - PGD_T_LOG2) << MIPS_PWSIZE_PTEW_SHIFT)
2486 & MIPS_PWSIZE_PTEW_MASK;
2487
2488 write_c0_pwsize(pwsize);
2489
2490 /* Make sure everything is set before we enable the HTW */
2491 back_to_back_c0_hazard();
2492
2493 /*
2494 * Enable HTW (and only for XUSeg on 64-bit), and disable the rest of
2495 * the pwctl fields.
2496 */
2497 config = 1 << MIPS_PWCTL_PWEN_SHIFT;
2498 if (IS_ENABLED(CONFIG_64BIT))
2499 config |= MIPS_PWCTL_XU_MASK;
2500 write_c0_pwctl(config);
2501 pr_info("Hardware Page Table Walker enabled\n");
2502
2503 print_htw_config();
2504 }
2505
config_xpa_params(void)2506 static void config_xpa_params(void)
2507 {
2508 #ifdef CONFIG_XPA
2509 unsigned int pagegrain;
2510
2511 if (mips_xpa_disabled) {
2512 pr_info("Extended Physical Addressing (XPA) disabled\n");
2513 return;
2514 }
2515
2516 pagegrain = read_c0_pagegrain();
2517 write_c0_pagegrain(pagegrain | PG_ELPA);
2518 back_to_back_c0_hazard();
2519 pagegrain = read_c0_pagegrain();
2520
2521 if (pagegrain & PG_ELPA)
2522 pr_info("Extended Physical Addressing (XPA) enabled\n");
2523 else
2524 panic("Extended Physical Addressing (XPA) disabled");
2525 #endif
2526 }
2527
check_pabits(void)2528 static void check_pabits(void)
2529 {
2530 unsigned long entry;
2531 unsigned pabits, fillbits;
2532
2533 if (!cpu_has_rixi || _PAGE_NO_EXEC == 0) {
2534 /*
2535 * We'll only be making use of the fact that we can rotate bits
2536 * into the fill if the CPU supports RIXI, so don't bother
2537 * probing this for CPUs which don't.
2538 */
2539 return;
2540 }
2541
2542 write_c0_entrylo0(~0ul);
2543 back_to_back_c0_hazard();
2544 entry = read_c0_entrylo0();
2545
2546 /* clear all non-PFN bits */
2547 entry &= ~((1 << MIPS_ENTRYLO_PFN_SHIFT) - 1);
2548 entry &= ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
2549
2550 /* find a lower bound on PABITS, and upper bound on fill bits */
2551 pabits = fls_long(entry) + 6;
2552 fillbits = max_t(int, (int)BITS_PER_LONG - pabits, 0);
2553
2554 /* minus the RI & XI bits */
2555 fillbits -= min_t(unsigned, fillbits, 2);
2556
2557 if (fillbits >= ilog2(_PAGE_NO_EXEC))
2558 fill_includes_sw_bits = true;
2559
2560 pr_debug("Entry* registers contain %u fill bits\n", fillbits);
2561 }
2562
build_tlb_refill_handler(void)2563 void build_tlb_refill_handler(void)
2564 {
2565 /*
2566 * The refill handler is generated per-CPU, multi-node systems
2567 * may have local storage for it. The other handlers are only
2568 * needed once.
2569 */
2570 static int run_once = 0;
2571
2572 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_rixi)
2573 panic("Kernels supporting XPA currently require CPUs with RIXI");
2574
2575 output_pgtable_bits_defines();
2576 check_pabits();
2577
2578 #ifdef CONFIG_64BIT
2579 check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_TABLE_ORDER + PAGE_SHIFT - 3);
2580 #endif
2581
2582 if (cpu_has_3kex) {
2583 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
2584 if (!run_once) {
2585 build_setup_pgd();
2586 build_r3000_tlb_refill_handler();
2587 build_r3000_tlb_load_handler();
2588 build_r3000_tlb_store_handler();
2589 build_r3000_tlb_modify_handler();
2590 flush_tlb_handlers();
2591 run_once++;
2592 }
2593 #else
2594 panic("No R3000 TLB refill handler");
2595 #endif
2596 return;
2597 }
2598
2599 if (cpu_has_ldpte)
2600 setup_pw();
2601
2602 if (!run_once) {
2603 scratch_reg = allocate_kscratch();
2604 build_setup_pgd();
2605 build_r4000_tlb_load_handler();
2606 build_r4000_tlb_store_handler();
2607 build_r4000_tlb_modify_handler();
2608 if (cpu_has_ldpte)
2609 build_loongson3_tlb_refill_handler();
2610 else
2611 build_r4000_tlb_refill_handler();
2612 flush_tlb_handlers();
2613 run_once++;
2614 }
2615 if (cpu_has_xpa)
2616 config_xpa_params();
2617 if (cpu_has_htw)
2618 config_htw_params();
2619 }
2620