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 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 extern int sb1250_m3_workaround_needed(void); 86 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 94 static inline int __maybe_unused r10000_llsc_war(void) 95 { 96 return IS_ENABLED(CONFIG_WAR_R10000_LLSC); 97 } 98 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 } 111 112 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 > 0 124 static bool scratchpad_available(void) 125 { 126 return true; 127 } 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 138 static bool scratchpad_available(void) 139 { 140 return false; 141 } 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 */ 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; 203 204 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 } 214 215 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 */ 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 } 259 260 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; 324 325 static inline int __maybe_unused c0_kscratch(void) 326 { 327 return 31; 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_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 */ 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 */ 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 } 494 495 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); 601 602 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 628 629 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 } 676 677 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 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 } 708 709 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 } 739 740 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 */ 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 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 */ 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 */ 973 974 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 } 983 984 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 if (cpu_has_mips_r2_exec_hazard) 2127 uasm_i_ehb(&p); 2128 2129 /* Examine entrylo 0 or 1 based on ptr. */ 2130 if (use_bbit_insns()) { 2131 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8); 2132 } else { 2133 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t)); 2134 uasm_i_beqz(&p, wr.r3, 8); 2135 } 2136 /* load it in the delay slot*/ 2137 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0); 2138 /* load it if ptr is odd */ 2139 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1); 2140 /* 2141 * If the entryLo (now in wr.r3) is valid (bit 1), RI or 2142 * XI must have triggered it. 2143 */ 2144 if (use_bbit_insns()) { 2145 uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl); 2146 uasm_i_nop(&p); 2147 uasm_l_tlbl_goaround1(&l, p); 2148 } else { 2149 uasm_i_andi(&p, wr.r3, wr.r3, 2); 2150 uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl); 2151 uasm_i_nop(&p); 2152 } 2153 uasm_l_tlbl_goaround1(&l, p); 2154 } 2155 build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3); 2156 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); 2157 2158 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 2159 /* 2160 * This is the entry point when build_r4000_tlbchange_handler_head 2161 * spots a huge page. 2162 */ 2163 uasm_l_tlb_huge_update(&l, p); 2164 iPTE_LW(&p, wr.r1, wr.r2); 2165 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl); 2166 build_tlb_probe_entry(&p); 2167 2168 if (cpu_has_rixi && !cpu_has_rixiex) { 2169 /* 2170 * If the page is not _PAGE_VALID, RI or XI could not 2171 * have triggered it. Skip the expensive test.. 2172 */ 2173 if (use_bbit_insns()) { 2174 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID), 2175 label_tlbl_goaround2); 2176 } else { 2177 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID); 2178 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2); 2179 } 2180 uasm_i_nop(&p); 2181 2182 /* 2183 * Warn if something may race with us & replace the TLB entry 2184 * before we read it here. Everything with such races should 2185 * also have dedicated RiXi exception handlers, so this 2186 * shouldn't be hit. 2187 */ 2188 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path"); 2189 2190 uasm_i_tlbr(&p); 2191 2192 if (cpu_has_mips_r2_exec_hazard) 2193 uasm_i_ehb(&p); 2194 2195 /* Examine entrylo 0 or 1 based on ptr. */ 2196 if (use_bbit_insns()) { 2197 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8); 2198 } else { 2199 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t)); 2200 uasm_i_beqz(&p, wr.r3, 8); 2201 } 2202 /* load it in the delay slot*/ 2203 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0); 2204 /* load it if ptr is odd */ 2205 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1); 2206 /* 2207 * If the entryLo (now in wr.r3) is valid (bit 1), RI or 2208 * XI must have triggered it. 2209 */ 2210 if (use_bbit_insns()) { 2211 uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2); 2212 } else { 2213 uasm_i_andi(&p, wr.r3, wr.r3, 2); 2214 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2); 2215 } 2216 if (PM_DEFAULT_MASK == 0) 2217 uasm_i_nop(&p); 2218 /* 2219 * We clobbered C0_PAGEMASK, restore it. On the other branch 2220 * it is restored in build_huge_tlb_write_entry. 2221 */ 2222 build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0); 2223 2224 uasm_l_tlbl_goaround2(&l, p); 2225 } 2226 uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID)); 2227 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); 2228 #endif 2229 2230 uasm_l_nopage_tlbl(&l, p); 2231 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) 2232 uasm_i_sync(&p, 0); 2233 build_restore_work_registers(&p); 2234 #ifdef CONFIG_CPU_MICROMIPS 2235 if ((unsigned long)tlb_do_page_fault_0 & 1) { 2236 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0)); 2237 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0)); 2238 uasm_i_jr(&p, K0); 2239 } else 2240 #endif 2241 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff); 2242 uasm_i_nop(&p); 2243 2244 if (p >= (u32 *)handle_tlbl_end) 2245 panic("TLB load handler fastpath space exceeded"); 2246 2247 uasm_resolve_relocs(relocs, labels); 2248 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n", 2249 (unsigned int)(p - (u32 *)handle_tlbl)); 2250 2251 dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_end); 2252 } 2253 2254 static void build_r4000_tlb_store_handler(void) 2255 { 2256 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbs); 2257 struct uasm_label *l = labels; 2258 struct uasm_reloc *r = relocs; 2259 struct work_registers wr; 2260 2261 memset(p, 0, handle_tlbs_end - (char *)p); 2262 memset(labels, 0, sizeof(labels)); 2263 memset(relocs, 0, sizeof(relocs)); 2264 2265 wr = build_r4000_tlbchange_handler_head(&p, &l, &r); 2266 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs); 2267 if (m4kc_tlbp_war()) 2268 build_tlb_probe_entry(&p); 2269 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3); 2270 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); 2271 2272 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 2273 /* 2274 * This is the entry point when 2275 * build_r4000_tlbchange_handler_head spots a huge page. 2276 */ 2277 uasm_l_tlb_huge_update(&l, p); 2278 iPTE_LW(&p, wr.r1, wr.r2); 2279 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs); 2280 build_tlb_probe_entry(&p); 2281 uasm_i_ori(&p, wr.r1, wr.r1, 2282 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); 2283 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); 2284 #endif 2285 2286 uasm_l_nopage_tlbs(&l, p); 2287 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) 2288 uasm_i_sync(&p, 0); 2289 build_restore_work_registers(&p); 2290 #ifdef CONFIG_CPU_MICROMIPS 2291 if ((unsigned long)tlb_do_page_fault_1 & 1) { 2292 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1)); 2293 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1)); 2294 uasm_i_jr(&p, K0); 2295 } else 2296 #endif 2297 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff); 2298 uasm_i_nop(&p); 2299 2300 if (p >= (u32 *)handle_tlbs_end) 2301 panic("TLB store handler fastpath space exceeded"); 2302 2303 uasm_resolve_relocs(relocs, labels); 2304 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n", 2305 (unsigned int)(p - (u32 *)handle_tlbs)); 2306 2307 dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_end); 2308 } 2309 2310 static void build_r4000_tlb_modify_handler(void) 2311 { 2312 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbm); 2313 struct uasm_label *l = labels; 2314 struct uasm_reloc *r = relocs; 2315 struct work_registers wr; 2316 2317 memset(p, 0, handle_tlbm_end - (char *)p); 2318 memset(labels, 0, sizeof(labels)); 2319 memset(relocs, 0, sizeof(relocs)); 2320 2321 wr = build_r4000_tlbchange_handler_head(&p, &l, &r); 2322 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm); 2323 if (m4kc_tlbp_war()) 2324 build_tlb_probe_entry(&p); 2325 /* Present and writable bits set, set accessed and dirty bits. */ 2326 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3); 2327 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); 2328 2329 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT 2330 /* 2331 * This is the entry point when 2332 * build_r4000_tlbchange_handler_head spots a huge page. 2333 */ 2334 uasm_l_tlb_huge_update(&l, p); 2335 iPTE_LW(&p, wr.r1, wr.r2); 2336 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm); 2337 build_tlb_probe_entry(&p); 2338 uasm_i_ori(&p, wr.r1, wr.r1, 2339 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); 2340 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0); 2341 #endif 2342 2343 uasm_l_nopage_tlbm(&l, p); 2344 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) 2345 uasm_i_sync(&p, 0); 2346 build_restore_work_registers(&p); 2347 #ifdef CONFIG_CPU_MICROMIPS 2348 if ((unsigned long)tlb_do_page_fault_1 & 1) { 2349 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1)); 2350 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1)); 2351 uasm_i_jr(&p, K0); 2352 } else 2353 #endif 2354 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff); 2355 uasm_i_nop(&p); 2356 2357 if (p >= (u32 *)handle_tlbm_end) 2358 panic("TLB modify handler fastpath space exceeded"); 2359 2360 uasm_resolve_relocs(relocs, labels); 2361 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n", 2362 (unsigned int)(p - (u32 *)handle_tlbm)); 2363 2364 dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_end); 2365 } 2366 2367 static void flush_tlb_handlers(void) 2368 { 2369 local_flush_icache_range((unsigned long)handle_tlbl, 2370 (unsigned long)handle_tlbl_end); 2371 local_flush_icache_range((unsigned long)handle_tlbs, 2372 (unsigned long)handle_tlbs_end); 2373 local_flush_icache_range((unsigned long)handle_tlbm, 2374 (unsigned long)handle_tlbm_end); 2375 local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd, 2376 (unsigned long)tlbmiss_handler_setup_pgd_end); 2377 } 2378 2379 static void print_htw_config(void) 2380 { 2381 unsigned long config; 2382 unsigned int pwctl; 2383 const int field = 2 * sizeof(unsigned long); 2384 2385 config = read_c0_pwfield(); 2386 pr_debug("PWField (0x%0*lx): GDI: 0x%02lx UDI: 0x%02lx MDI: 0x%02lx PTI: 0x%02lx PTEI: 0x%02lx\n", 2387 field, config, 2388 (config & MIPS_PWFIELD_GDI_MASK) >> MIPS_PWFIELD_GDI_SHIFT, 2389 (config & MIPS_PWFIELD_UDI_MASK) >> MIPS_PWFIELD_UDI_SHIFT, 2390 (config & MIPS_PWFIELD_MDI_MASK) >> MIPS_PWFIELD_MDI_SHIFT, 2391 (config & MIPS_PWFIELD_PTI_MASK) >> MIPS_PWFIELD_PTI_SHIFT, 2392 (config & MIPS_PWFIELD_PTEI_MASK) >> MIPS_PWFIELD_PTEI_SHIFT); 2393 2394 config = read_c0_pwsize(); 2395 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", 2396 field, config, 2397 (config & MIPS_PWSIZE_PS_MASK) >> MIPS_PWSIZE_PS_SHIFT, 2398 (config & MIPS_PWSIZE_GDW_MASK) >> MIPS_PWSIZE_GDW_SHIFT, 2399 (config & MIPS_PWSIZE_UDW_MASK) >> MIPS_PWSIZE_UDW_SHIFT, 2400 (config & MIPS_PWSIZE_MDW_MASK) >> MIPS_PWSIZE_MDW_SHIFT, 2401 (config & MIPS_PWSIZE_PTW_MASK) >> MIPS_PWSIZE_PTW_SHIFT, 2402 (config & MIPS_PWSIZE_PTEW_MASK) >> MIPS_PWSIZE_PTEW_SHIFT); 2403 2404 pwctl = read_c0_pwctl(); 2405 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", 2406 pwctl, 2407 (pwctl & MIPS_PWCTL_PWEN_MASK) >> MIPS_PWCTL_PWEN_SHIFT, 2408 (pwctl & MIPS_PWCTL_XK_MASK) >> MIPS_PWCTL_XK_SHIFT, 2409 (pwctl & MIPS_PWCTL_XS_MASK) >> MIPS_PWCTL_XS_SHIFT, 2410 (pwctl & MIPS_PWCTL_XU_MASK) >> MIPS_PWCTL_XU_SHIFT, 2411 (pwctl & MIPS_PWCTL_DPH_MASK) >> MIPS_PWCTL_DPH_SHIFT, 2412 (pwctl & MIPS_PWCTL_HUGEPG_MASK) >> MIPS_PWCTL_HUGEPG_SHIFT, 2413 (pwctl & MIPS_PWCTL_PSN_MASK) >> MIPS_PWCTL_PSN_SHIFT); 2414 } 2415 2416 static void config_htw_params(void) 2417 { 2418 unsigned long pwfield, pwsize, ptei; 2419 unsigned int config; 2420 2421 /* 2422 * We are using 2-level page tables, so we only need to 2423 * setup GDW and PTW appropriately. UDW and MDW will remain 0. 2424 * The default value of GDI/UDI/MDI/PTI is 0xc. It is illegal to 2425 * write values less than 0xc in these fields because the entire 2426 * write will be dropped. As a result of which, we must preserve 2427 * the original reset values and overwrite only what we really want. 2428 */ 2429 2430 pwfield = read_c0_pwfield(); 2431 /* re-initialize the GDI field */ 2432 pwfield &= ~MIPS_PWFIELD_GDI_MASK; 2433 pwfield |= PGDIR_SHIFT << MIPS_PWFIELD_GDI_SHIFT; 2434 /* re-initialize the PTI field including the even/odd bit */ 2435 pwfield &= ~MIPS_PWFIELD_PTI_MASK; 2436 pwfield |= PAGE_SHIFT << MIPS_PWFIELD_PTI_SHIFT; 2437 if (CONFIG_PGTABLE_LEVELS >= 3) { 2438 pwfield &= ~MIPS_PWFIELD_MDI_MASK; 2439 pwfield |= PMD_SHIFT << MIPS_PWFIELD_MDI_SHIFT; 2440 } 2441 /* Set the PTEI right shift */ 2442 ptei = _PAGE_GLOBAL_SHIFT << MIPS_PWFIELD_PTEI_SHIFT; 2443 pwfield |= ptei; 2444 write_c0_pwfield(pwfield); 2445 /* Check whether the PTEI value is supported */ 2446 back_to_back_c0_hazard(); 2447 pwfield = read_c0_pwfield(); 2448 if (((pwfield & MIPS_PWFIELD_PTEI_MASK) << MIPS_PWFIELD_PTEI_SHIFT) 2449 != ptei) { 2450 pr_warn("Unsupported PTEI field value: 0x%lx. HTW will not be enabled", 2451 ptei); 2452 /* 2453 * Drop option to avoid HTW being enabled via another path 2454 * (eg htw_reset()) 2455 */ 2456 current_cpu_data.options &= ~MIPS_CPU_HTW; 2457 return; 2458 } 2459 2460 pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT; 2461 pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT; 2462 if (CONFIG_PGTABLE_LEVELS >= 3) 2463 pwsize |= ilog2(PTRS_PER_PMD) << MIPS_PWSIZE_MDW_SHIFT; 2464 2465 /* Set pointer size to size of directory pointers */ 2466 if (IS_ENABLED(CONFIG_64BIT)) 2467 pwsize |= MIPS_PWSIZE_PS_MASK; 2468 /* PTEs may be multiple pointers long (e.g. with XPA) */ 2469 pwsize |= ((PTE_T_LOG2 - PGD_T_LOG2) << MIPS_PWSIZE_PTEW_SHIFT) 2470 & MIPS_PWSIZE_PTEW_MASK; 2471 2472 write_c0_pwsize(pwsize); 2473 2474 /* Make sure everything is set before we enable the HTW */ 2475 back_to_back_c0_hazard(); 2476 2477 /* 2478 * Enable HTW (and only for XUSeg on 64-bit), and disable the rest of 2479 * the pwctl fields. 2480 */ 2481 config = 1 << MIPS_PWCTL_PWEN_SHIFT; 2482 if (IS_ENABLED(CONFIG_64BIT)) 2483 config |= MIPS_PWCTL_XU_MASK; 2484 write_c0_pwctl(config); 2485 pr_info("Hardware Page Table Walker enabled\n"); 2486 2487 print_htw_config(); 2488 } 2489 2490 static void config_xpa_params(void) 2491 { 2492 #ifdef CONFIG_XPA 2493 unsigned int pagegrain; 2494 2495 if (mips_xpa_disabled) { 2496 pr_info("Extended Physical Addressing (XPA) disabled\n"); 2497 return; 2498 } 2499 2500 pagegrain = read_c0_pagegrain(); 2501 write_c0_pagegrain(pagegrain | PG_ELPA); 2502 back_to_back_c0_hazard(); 2503 pagegrain = read_c0_pagegrain(); 2504 2505 if (pagegrain & PG_ELPA) 2506 pr_info("Extended Physical Addressing (XPA) enabled\n"); 2507 else 2508 panic("Extended Physical Addressing (XPA) disabled"); 2509 #endif 2510 } 2511 2512 static void check_pabits(void) 2513 { 2514 unsigned long entry; 2515 unsigned pabits, fillbits; 2516 2517 if (!cpu_has_rixi || _PAGE_NO_EXEC == 0) { 2518 /* 2519 * We'll only be making use of the fact that we can rotate bits 2520 * into the fill if the CPU supports RIXI, so don't bother 2521 * probing this for CPUs which don't. 2522 */ 2523 return; 2524 } 2525 2526 write_c0_entrylo0(~0ul); 2527 back_to_back_c0_hazard(); 2528 entry = read_c0_entrylo0(); 2529 2530 /* clear all non-PFN bits */ 2531 entry &= ~((1 << MIPS_ENTRYLO_PFN_SHIFT) - 1); 2532 entry &= ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI); 2533 2534 /* find a lower bound on PABITS, and upper bound on fill bits */ 2535 pabits = fls_long(entry) + 6; 2536 fillbits = max_t(int, (int)BITS_PER_LONG - pabits, 0); 2537 2538 /* minus the RI & XI bits */ 2539 fillbits -= min_t(unsigned, fillbits, 2); 2540 2541 if (fillbits >= ilog2(_PAGE_NO_EXEC)) 2542 fill_includes_sw_bits = true; 2543 2544 pr_debug("Entry* registers contain %u fill bits\n", fillbits); 2545 } 2546 2547 void build_tlb_refill_handler(void) 2548 { 2549 /* 2550 * The refill handler is generated per-CPU, multi-node systems 2551 * may have local storage for it. The other handlers are only 2552 * needed once. 2553 */ 2554 static int run_once = 0; 2555 2556 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_rixi) 2557 panic("Kernels supporting XPA currently require CPUs with RIXI"); 2558 2559 output_pgtable_bits_defines(); 2560 check_pabits(); 2561 2562 #ifdef CONFIG_64BIT 2563 check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_TABLE_ORDER + PAGE_SHIFT - 3); 2564 #endif 2565 2566 if (cpu_has_3kex) { 2567 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT 2568 if (!run_once) { 2569 build_setup_pgd(); 2570 build_r3000_tlb_refill_handler(); 2571 build_r3000_tlb_load_handler(); 2572 build_r3000_tlb_store_handler(); 2573 build_r3000_tlb_modify_handler(); 2574 flush_tlb_handlers(); 2575 run_once++; 2576 } 2577 #else 2578 panic("No R3000 TLB refill handler"); 2579 #endif 2580 return; 2581 } 2582 2583 if (cpu_has_ldpte) 2584 setup_pw(); 2585 2586 if (!run_once) { 2587 scratch_reg = allocate_kscratch(); 2588 build_setup_pgd(); 2589 build_r4000_tlb_load_handler(); 2590 build_r4000_tlb_store_handler(); 2591 build_r4000_tlb_modify_handler(); 2592 if (cpu_has_ldpte) 2593 build_loongson3_tlb_refill_handler(); 2594 else 2595 build_r4000_tlb_refill_handler(); 2596 flush_tlb_handlers(); 2597 run_once++; 2598 } 2599 if (cpu_has_xpa) 2600 config_xpa_params(); 2601 if (cpu_has_htw) 2602 config_htw_params(); 2603 } 2604