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
6 * Synthesize TLB refill handlers at runtime.
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.
13 * ... and the days got worse and worse and now you see
14 * I've gone completly out of my mind.
16 * They're coming to take me a away haha
17 * they're coming to take me a away hoho hihi haha
18 * to the funny farm where code is beautiful all the time ...
20 * (Condolences to Napoleon XIV)
23 #include <linux/bug.h>
24 #include <linux/kernel.h>
25 #include <linux/types.h>
26 #include <linux/smp.h>
27 #include <linux/string.h>
28 #include <linux/init.h>
30 #include <asm/mmu_context.h>
35 static inline int r45k_bvahwbug(void)
37 /* XXX: We should probe for the presence of this bug, but we don't. */
41 static inline int r4k_250MHZhwbug(void)
43 /* XXX: We should probe for the presence of this bug, but we don't. */
47 static inline int __maybe_unused bcm1250_m3_war(void)
49 return BCM1250_M3_WAR;
52 static inline int __maybe_unused r10000_llsc_war(void)
54 return R10000_LLSC_WAR;
58 * Found by experiment: At least some revisions of the 4kc throw under
59 * some circumstances a machine check exception, triggered by invalid
60 * values in the index register. Delaying the tlbp instruction until
61 * after the next branch, plus adding an additional nop in front of
62 * tlbwi/tlbwr avoids the invalid index register values. Nobody knows
63 * why; it's not an issue caused by the core RTL.
66 static int __cpuinit m4kc_tlbp_war(void)
68 return (current_cpu_data.processor_id & 0xffff00) ==
69 (PRID_COMP_MIPS | PRID_IMP_4KC);
72 /* Handle labels (which must be positive integers). */
74 label_second_part = 1,
86 label_smp_pgtable_change,
87 label_r3000_write_probe_fail,
88 #ifdef CONFIG_HUGETLB_PAGE
89 label_tlb_huge_update,
93 UASM_L_LA(_second_part)
96 UASM_L_LA(_module_alloc)
99 UASM_L_LA(_vmalloc_done)
100 UASM_L_LA(_tlbw_hazard)
102 UASM_L_LA(_nopage_tlbl)
103 UASM_L_LA(_nopage_tlbs)
104 UASM_L_LA(_nopage_tlbm)
105 UASM_L_LA(_smp_pgtable_change)
106 UASM_L_LA(_r3000_write_probe_fail)
107 #ifdef CONFIG_HUGETLB_PAGE
108 UASM_L_LA(_tlb_huge_update)
112 * For debug purposes.
114 static inline void dump_handler(const u32 *handler, int count)
118 pr_debug("\t.set push\n");
119 pr_debug("\t.set noreorder\n");
121 for (i = 0; i < count; i++)
122 pr_debug("\t%p\t.word 0x%08x\n", &handler[i], handler[i]);
124 pr_debug("\t.set pop\n");
127 /* The only general purpose registers allowed in TLB handlers. */
131 /* Some CP0 registers */
132 #define C0_INDEX 0, 0
133 #define C0_ENTRYLO0 2, 0
134 #define C0_TCBIND 2, 2
135 #define C0_ENTRYLO1 3, 0
136 #define C0_CONTEXT 4, 0
137 #define C0_PAGEMASK 5, 0
138 #define C0_BADVADDR 8, 0
139 #define C0_ENTRYHI 10, 0
141 #define C0_XCONTEXT 20, 0
144 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT)
146 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT)
149 /* The worst case length of the handler is around 18 instructions for
150 * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
151 * Maximum space available is 32 instructions for R3000 and 64
152 * instructions for R4000.
154 * We deliberately chose a buffer size of 128, so we won't scribble
155 * over anything important on overflow before we panic.
157 static u32 tlb_handler[128] __cpuinitdata;
159 /* simply assume worst case size for labels and relocs */
160 static struct uasm_label labels[128] __cpuinitdata;
161 static struct uasm_reloc relocs[128] __cpuinitdata;
164 * The R3000 TLB handler is simple.
166 static void __cpuinit build_r3000_tlb_refill_handler(void)
168 long pgdc = (long)pgd_current;
171 memset(tlb_handler, 0, sizeof(tlb_handler));
174 uasm_i_mfc0(&p, K0, C0_BADVADDR);
175 uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */
176 uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1);
177 uasm_i_srl(&p, K0, K0, 22); /* load delay */
178 uasm_i_sll(&p, K0, K0, 2);
179 uasm_i_addu(&p, K1, K1, K0);
180 uasm_i_mfc0(&p, K0, C0_CONTEXT);
181 uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */
182 uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */
183 uasm_i_addu(&p, K1, K1, K0);
184 uasm_i_lw(&p, K0, 0, K1);
185 uasm_i_nop(&p); /* load delay */
186 uasm_i_mtc0(&p, K0, C0_ENTRYLO0);
187 uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
188 uasm_i_tlbwr(&p); /* cp0 delay */
190 uasm_i_rfe(&p); /* branch delay */
192 if (p > tlb_handler + 32)
193 panic("TLB refill handler space exceeded");
195 pr_debug("Wrote TLB refill handler (%u instructions).\n",
196 (unsigned int)(p - tlb_handler));
198 memcpy((void *)ebase, tlb_handler, 0x80);
200 dump_handler((u32 *)ebase, 32);
204 * The R4000 TLB handler is much more complicated. We have two
205 * consecutive handler areas with 32 instructions space each.
206 * Since they aren't used at the same time, we can overflow in the
207 * other one.To keep things simple, we first assume linear space,
208 * then we relocate it to the final handler layout as needed.
210 static u32 final_handler[64] __cpuinitdata;
215 * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
216 * 2. A timing hazard exists for the TLBP instruction.
218 * stalling_instruction
221 * The JTLB is being read for the TLBP throughout the stall generated by the
222 * previous instruction. This is not really correct as the stalling instruction
223 * can modify the address used to access the JTLB. The failure symptom is that
224 * the TLBP instruction will use an address created for the stalling instruction
225 * and not the address held in C0_ENHI and thus report the wrong results.
227 * The software work-around is to not allow the instruction preceding the TLBP
228 * to stall - make it an NOP or some other instruction guaranteed not to stall.
230 * Errata 2 will not be fixed. This errata is also on the R5000.
232 * As if we MIPS hackers wouldn't know how to nop pipelines happy ...
234 static void __cpuinit __maybe_unused build_tlb_probe_entry(u32 **p)
236 switch (current_cpu_type()) {
237 /* Found by experiment: R4600 v2.0/R4700 needs this, too. */
254 * Write random or indexed TLB entry, and care about the hazards from
255 * the preceeding mtc0 and for the following eret.
257 enum tlb_write_entry { tlb_random, tlb_indexed };
259 static void __cpuinit build_tlb_write_entry(u32 **p, struct uasm_label **l,
260 struct uasm_reloc **r,
261 enum tlb_write_entry wmode)
263 void(*tlbw)(u32 **) = NULL;
266 case tlb_random: tlbw = uasm_i_tlbwr; break;
267 case tlb_indexed: tlbw = uasm_i_tlbwi; break;
270 if (cpu_has_mips_r2) {
271 if (cpu_has_mips_r2_exec_hazard)
277 switch (current_cpu_type()) {
285 * This branch uses up a mtc0 hazard nop slot and saves
286 * two nops after the tlbw instruction.
288 uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
290 uasm_l_tlbw_hazard(l, *p);
332 uasm_i_nop(p); /* QED specifies 2 nops hazard */
334 * This branch uses up a mtc0 hazard nop slot and saves
335 * a nop after the tlbw instruction.
337 uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
339 uasm_l_tlbw_hazard(l, *p);
352 * When the JTLB is updated by tlbwi or tlbwr, a subsequent
353 * use of the JTLB for instructions should not occur for 4
354 * cpu cycles and use for data translations should not occur
389 panic("No TLB refill handler yet (CPU type: %d)",
390 current_cpu_data.cputype);
395 #ifdef CONFIG_HUGETLB_PAGE
396 static __cpuinit void build_huge_tlb_write_entry(u32 **p,
397 struct uasm_label **l,
398 struct uasm_reloc **r,
400 enum tlb_write_entry wmode)
402 /* Set huge page tlb entry size */
403 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
404 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
405 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
407 build_tlb_write_entry(p, l, r, wmode);
409 /* Reset default page size */
410 if (PM_DEFAULT_MASK >> 16) {
411 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
412 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
413 uasm_il_b(p, r, label_leave);
414 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
415 } else if (PM_DEFAULT_MASK) {
416 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
417 uasm_il_b(p, r, label_leave);
418 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
420 uasm_il_b(p, r, label_leave);
421 uasm_i_mtc0(p, 0, C0_PAGEMASK);
426 * Check if Huge PTE is present, if so then jump to LABEL.
428 static void __cpuinit
429 build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
430 unsigned int pmd, int lid)
432 UASM_i_LW(p, tmp, 0, pmd);
433 uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
434 uasm_il_bnez(p, r, tmp, lid);
437 static __cpuinit void build_huge_update_entries(u32 **p,
444 * A huge PTE describes an area the size of the
445 * configured huge page size. This is twice the
446 * of the large TLB entry size we intend to use.
447 * A TLB entry half the size of the configured
448 * huge page size is configured into entrylo0
449 * and entrylo1 to cover the contiguous huge PTE
452 small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
454 /* We can clobber tmp. It isn't used after this.*/
456 uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
458 UASM_i_SRL(p, pte, pte, 6); /* convert to entrylo */
459 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* load it */
460 /* convert to entrylo1 */
462 UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
464 UASM_i_ADDU(p, pte, pte, tmp);
466 uasm_i_mtc0(p, pte, C0_ENTRYLO1); /* load it */
469 static __cpuinit void build_huge_handler_tail(u32 **p,
470 struct uasm_reloc **r,
471 struct uasm_label **l,
476 UASM_i_SC(p, pte, 0, ptr);
477 uasm_il_beqz(p, r, pte, label_tlb_huge_update);
478 UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
480 UASM_i_SW(p, pte, 0, ptr);
482 build_huge_update_entries(p, pte, ptr);
483 build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed);
485 #endif /* CONFIG_HUGETLB_PAGE */
489 * TMP and PTR are scratch.
490 * TMP will be clobbered, PTR will hold the pmd entry.
492 static void __cpuinit
493 build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
494 unsigned int tmp, unsigned int ptr)
496 long pgdc = (long)pgd_current;
499 * The vmalloc handling is not in the hotpath.
501 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
502 uasm_il_bltz(p, r, tmp, label_vmalloc);
503 /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
506 # ifdef CONFIG_MIPS_MT_SMTC
508 * SMTC uses TCBind value as "CPU" index
510 uasm_i_mfc0(p, ptr, C0_TCBIND);
511 uasm_i_dsrl(p, ptr, ptr, 19);
514 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
517 uasm_i_dmfc0(p, ptr, C0_CONTEXT);
518 uasm_i_dsrl(p, ptr, ptr, 23);
520 UASM_i_LA_mostly(p, tmp, pgdc);
521 uasm_i_daddu(p, ptr, ptr, tmp);
522 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
523 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
525 UASM_i_LA_mostly(p, ptr, pgdc);
526 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
529 uasm_l_vmalloc_done(l, *p);
531 if (PGDIR_SHIFT - 3 < 32) /* get pgd offset in bytes */
532 uasm_i_dsrl(p, tmp, tmp, PGDIR_SHIFT-3);
534 uasm_i_dsrl32(p, tmp, tmp, PGDIR_SHIFT - 3 - 32);
536 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
537 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
538 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
539 uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
540 uasm_i_dsrl(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
541 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
542 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
546 * BVADDR is the faulting address, PTR is scratch.
547 * PTR will hold the pgd for vmalloc.
549 static void __cpuinit
550 build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
551 unsigned int bvaddr, unsigned int ptr)
553 long swpd = (long)swapper_pg_dir;
555 uasm_l_vmalloc(l, *p);
557 if (uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd)) {
558 uasm_il_b(p, r, label_vmalloc_done);
559 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
561 UASM_i_LA_mostly(p, ptr, swpd);
562 uasm_il_b(p, r, label_vmalloc_done);
563 if (uasm_in_compat_space_p(swpd))
564 uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
566 uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
570 #else /* !CONFIG_64BIT */
573 * TMP and PTR are scratch.
574 * TMP will be clobbered, PTR will hold the pgd entry.
576 static void __cpuinit __maybe_unused
577 build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
579 long pgdc = (long)pgd_current;
581 /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
583 #ifdef CONFIG_MIPS_MT_SMTC
585 * SMTC uses TCBind value as "CPU" index
587 uasm_i_mfc0(p, ptr, C0_TCBIND);
588 UASM_i_LA_mostly(p, tmp, pgdc);
589 uasm_i_srl(p, ptr, ptr, 19);
592 * smp_processor_id() << 3 is stored in CONTEXT.
594 uasm_i_mfc0(p, ptr, C0_CONTEXT);
595 UASM_i_LA_mostly(p, tmp, pgdc);
596 uasm_i_srl(p, ptr, ptr, 23);
598 uasm_i_addu(p, ptr, tmp, ptr);
600 UASM_i_LA_mostly(p, ptr, pgdc);
602 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
603 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
604 uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
605 uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
606 uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
609 #endif /* !CONFIG_64BIT */
611 static void __cpuinit build_adjust_context(u32 **p, unsigned int ctx)
613 unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
614 unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
616 switch (current_cpu_type()) {
633 UASM_i_SRL(p, ctx, ctx, shift);
634 uasm_i_andi(p, ctx, ctx, mask);
637 static void __cpuinit build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
640 * Bug workaround for the Nevada. It seems as if under certain
641 * circumstances the move from cp0_context might produce a
642 * bogus result when the mfc0 instruction and its consumer are
643 * in a different cacheline or a load instruction, probably any
644 * memory reference, is between them.
646 switch (current_cpu_type()) {
648 UASM_i_LW(p, ptr, 0, ptr);
649 GET_CONTEXT(p, tmp); /* get context reg */
653 GET_CONTEXT(p, tmp); /* get context reg */
654 UASM_i_LW(p, ptr, 0, ptr);
658 build_adjust_context(p, tmp);
659 UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
662 static void __cpuinit build_update_entries(u32 **p, unsigned int tmp,
666 * 64bit address support (36bit on a 32bit CPU) in a 32bit
667 * Kernel is a special case. Only a few CPUs use it.
669 #ifdef CONFIG_64BIT_PHYS_ADDR
670 if (cpu_has_64bits) {
671 uasm_i_ld(p, tmp, 0, ptep); /* get even pte */
672 uasm_i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
673 uasm_i_dsrl(p, tmp, tmp, 6); /* convert to entrylo0 */
674 uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
675 uasm_i_dsrl(p, ptep, ptep, 6); /* convert to entrylo1 */
676 uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
678 int pte_off_even = sizeof(pte_t) / 2;
679 int pte_off_odd = pte_off_even + sizeof(pte_t);
681 /* The pte entries are pre-shifted */
682 uasm_i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
683 uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
684 uasm_i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
685 uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
688 UASM_i_LW(p, tmp, 0, ptep); /* get even pte */
689 UASM_i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
691 build_tlb_probe_entry(p);
692 UASM_i_SRL(p, tmp, tmp, 6); /* convert to entrylo0 */
693 if (r4k_250MHZhwbug())
694 uasm_i_mtc0(p, 0, C0_ENTRYLO0);
695 uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
696 UASM_i_SRL(p, ptep, ptep, 6); /* convert to entrylo1 */
698 uasm_i_mfc0(p, tmp, C0_INDEX);
699 if (r4k_250MHZhwbug())
700 uasm_i_mtc0(p, 0, C0_ENTRYLO1);
701 uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
706 * For a 64-bit kernel, we are using the 64-bit XTLB refill exception
707 * because EXL == 0. If we wrap, we can also use the 32 instruction
708 * slots before the XTLB refill exception handler which belong to the
709 * unused TLB refill exception.
711 #define MIPS64_REFILL_INSNS 32
713 static void __cpuinit build_r4000_tlb_refill_handler(void)
715 u32 *p = tlb_handler;
716 struct uasm_label *l = labels;
717 struct uasm_reloc *r = relocs;
719 unsigned int final_len;
721 memset(tlb_handler, 0, sizeof(tlb_handler));
722 memset(labels, 0, sizeof(labels));
723 memset(relocs, 0, sizeof(relocs));
724 memset(final_handler, 0, sizeof(final_handler));
727 * create the plain linear handler
729 if (bcm1250_m3_war()) {
730 UASM_i_MFC0(&p, K0, C0_BADVADDR);
731 UASM_i_MFC0(&p, K1, C0_ENTRYHI);
732 uasm_i_xor(&p, K0, K0, K1);
733 UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
734 uasm_il_bnez(&p, &r, K0, label_leave);
735 /* No need for uasm_i_nop */
739 build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
741 build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
744 #ifdef CONFIG_HUGETLB_PAGE
745 build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
748 build_get_ptep(&p, K0, K1);
749 build_update_entries(&p, K0, K1);
750 build_tlb_write_entry(&p, &l, &r, tlb_random);
752 uasm_i_eret(&p); /* return from trap */
754 #ifdef CONFIG_HUGETLB_PAGE
755 uasm_l_tlb_huge_update(&l, p);
756 UASM_i_LW(&p, K0, 0, K1);
757 build_huge_update_entries(&p, K0, K1);
758 build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random);
762 build_get_pgd_vmalloc64(&p, &l, &r, K0, K1);
766 * Overflow check: For the 64bit handler, we need at least one
767 * free instruction slot for the wrap-around branch. In worst
768 * case, if the intended insertion point is a delay slot, we
769 * need three, with the second nop'ed and the third being
772 /* Loongson2 ebase is different than r4k, we have more space */
773 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
774 if ((p - tlb_handler) > 64)
775 panic("TLB refill handler space exceeded");
777 if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
778 || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
779 && uasm_insn_has_bdelay(relocs,
780 tlb_handler + MIPS64_REFILL_INSNS - 3)))
781 panic("TLB refill handler space exceeded");
785 * Now fold the handler in the TLB refill handler space.
787 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
789 /* Simplest case, just copy the handler. */
790 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
791 final_len = p - tlb_handler;
792 #else /* CONFIG_64BIT */
793 f = final_handler + MIPS64_REFILL_INSNS;
794 if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
795 /* Just copy the handler. */
796 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
797 final_len = p - tlb_handler;
799 #if defined(CONFIG_HUGETLB_PAGE)
800 const enum label_id ls = label_tlb_huge_update;
801 #elif defined(MODULE_START)
802 const enum label_id ls = label_module_alloc;
804 const enum label_id ls = label_vmalloc;
810 for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
812 BUG_ON(i == ARRAY_SIZE(labels));
813 split = labels[i].addr;
816 * See if we have overflown one way or the other.
818 if (split > tlb_handler + MIPS64_REFILL_INSNS ||
819 split < p - MIPS64_REFILL_INSNS)
824 * Split two instructions before the end. One
825 * for the branch and one for the instruction
828 split = tlb_handler + MIPS64_REFILL_INSNS - 2;
831 * If the branch would fall in a delay slot,
832 * we must back up an additional instruction
833 * so that it is no longer in a delay slot.
835 if (uasm_insn_has_bdelay(relocs, split - 1))
838 /* Copy first part of the handler. */
839 uasm_copy_handler(relocs, labels, tlb_handler, split, f);
840 f += split - tlb_handler;
844 uasm_l_split(&l, final_handler);
845 uasm_il_b(&f, &r, label_split);
846 if (uasm_insn_has_bdelay(relocs, split))
849 uasm_copy_handler(relocs, labels,
850 split, split + 1, f);
851 uasm_move_labels(labels, f, f + 1, -1);
857 /* Copy the rest of the handler. */
858 uasm_copy_handler(relocs, labels, split, p, final_handler);
859 final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
862 #endif /* CONFIG_64BIT */
864 uasm_resolve_relocs(relocs, labels);
865 pr_debug("Wrote TLB refill handler (%u instructions).\n",
868 memcpy((void *)ebase, final_handler, 0x100);
870 dump_handler((u32 *)ebase, 64);
874 * TLB load/store/modify handlers.
876 * Only the fastpath gets synthesized at runtime, the slowpath for
877 * do_page_fault remains normal asm.
879 extern void tlb_do_page_fault_0(void);
880 extern void tlb_do_page_fault_1(void);
883 * 128 instructions for the fastpath handler is generous and should
886 #define FASTPATH_SIZE 128
888 u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned;
889 u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned;
890 u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned;
892 static void __cpuinit
893 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
896 # ifdef CONFIG_64BIT_PHYS_ADDR
898 uasm_i_lld(p, pte, 0, ptr);
901 UASM_i_LL(p, pte, 0, ptr);
903 # ifdef CONFIG_64BIT_PHYS_ADDR
905 uasm_i_ld(p, pte, 0, ptr);
908 UASM_i_LW(p, pte, 0, ptr);
912 static void __cpuinit
913 iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
916 #ifdef CONFIG_64BIT_PHYS_ADDR
917 unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
920 uasm_i_ori(p, pte, pte, mode);
922 # ifdef CONFIG_64BIT_PHYS_ADDR
924 uasm_i_scd(p, pte, 0, ptr);
927 UASM_i_SC(p, pte, 0, ptr);
929 if (r10000_llsc_war())
930 uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
932 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
934 # ifdef CONFIG_64BIT_PHYS_ADDR
935 if (!cpu_has_64bits) {
936 /* no uasm_i_nop needed */
937 uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
938 uasm_i_ori(p, pte, pte, hwmode);
939 uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
940 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
941 /* no uasm_i_nop needed */
942 uasm_i_lw(p, pte, 0, ptr);
949 # ifdef CONFIG_64BIT_PHYS_ADDR
951 uasm_i_sd(p, pte, 0, ptr);
954 UASM_i_SW(p, pte, 0, ptr);
956 # ifdef CONFIG_64BIT_PHYS_ADDR
957 if (!cpu_has_64bits) {
958 uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
959 uasm_i_ori(p, pte, pte, hwmode);
960 uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
961 uasm_i_lw(p, pte, 0, ptr);
968 * Check if PTE is present, if not then jump to LABEL. PTR points to
969 * the page table where this PTE is located, PTE will be re-loaded
970 * with it's original value.
972 static void __cpuinit
973 build_pte_present(u32 **p, struct uasm_reloc **r,
974 unsigned int pte, unsigned int ptr, enum label_id lid)
976 uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
977 uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
978 uasm_il_bnez(p, r, pte, lid);
979 iPTE_LW(p, pte, ptr);
982 /* Make PTE valid, store result in PTR. */
983 static void __cpuinit
984 build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
987 unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
989 iPTE_SW(p, r, pte, ptr, mode);
993 * Check if PTE can be written to, if not branch to LABEL. Regardless
994 * restore PTE with value from PTR when done.
996 static void __cpuinit
997 build_pte_writable(u32 **p, struct uasm_reloc **r,
998 unsigned int pte, unsigned int ptr, enum label_id lid)
1000 uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1001 uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1002 uasm_il_bnez(p, r, pte, lid);
1003 iPTE_LW(p, pte, ptr);
1006 /* Make PTE writable, update software status bits as well, then store
1009 static void __cpuinit
1010 build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
1013 unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1016 iPTE_SW(p, r, pte, ptr, mode);
1020 * Check if PTE can be modified, if not branch to LABEL. Regardless
1021 * restore PTE with value from PTR when done.
1023 static void __cpuinit
1024 build_pte_modifiable(u32 **p, struct uasm_reloc **r,
1025 unsigned int pte, unsigned int ptr, enum label_id lid)
1027 uasm_i_andi(p, pte, pte, _PAGE_WRITE);
1028 uasm_il_beqz(p, r, pte, lid);
1029 iPTE_LW(p, pte, ptr);
1033 * R3000 style TLB load/store/modify handlers.
1037 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1040 static void __cpuinit
1041 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1043 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1044 uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1047 uasm_i_rfe(p); /* branch delay */
1051 * This places the pte into ENTRYLO0 and writes it with tlbwi
1052 * or tlbwr as appropriate. This is because the index register
1053 * may have the probe fail bit set as a result of a trap on a
1054 * kseg2 access, i.e. without refill. Then it returns.
1056 static void __cpuinit
1057 build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
1058 struct uasm_reloc **r, unsigned int pte,
1061 uasm_i_mfc0(p, tmp, C0_INDEX);
1062 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1063 uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1064 uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
1065 uasm_i_tlbwi(p); /* cp0 delay */
1067 uasm_i_rfe(p); /* branch delay */
1068 uasm_l_r3000_write_probe_fail(l, *p);
1069 uasm_i_tlbwr(p); /* cp0 delay */
1071 uasm_i_rfe(p); /* branch delay */
1074 static void __cpuinit
1075 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1078 long pgdc = (long)pgd_current;
1080 uasm_i_mfc0(p, pte, C0_BADVADDR);
1081 uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
1082 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
1083 uasm_i_srl(p, pte, pte, 22); /* load delay */
1084 uasm_i_sll(p, pte, pte, 2);
1085 uasm_i_addu(p, ptr, ptr, pte);
1086 uasm_i_mfc0(p, pte, C0_CONTEXT);
1087 uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
1088 uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
1089 uasm_i_addu(p, ptr, ptr, pte);
1090 uasm_i_lw(p, pte, 0, ptr);
1091 uasm_i_tlbp(p); /* load delay */
1094 static void __cpuinit build_r3000_tlb_load_handler(void)
1096 u32 *p = handle_tlbl;
1097 struct uasm_label *l = labels;
1098 struct uasm_reloc *r = relocs;
1100 memset(handle_tlbl, 0, sizeof(handle_tlbl));
1101 memset(labels, 0, sizeof(labels));
1102 memset(relocs, 0, sizeof(relocs));
1104 build_r3000_tlbchange_handler_head(&p, K0, K1);
1105 build_pte_present(&p, &r, K0, K1, label_nopage_tlbl);
1106 uasm_i_nop(&p); /* load delay */
1107 build_make_valid(&p, &r, K0, K1);
1108 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1110 uasm_l_nopage_tlbl(&l, p);
1111 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1114 if ((p - handle_tlbl) > FASTPATH_SIZE)
1115 panic("TLB load handler fastpath space exceeded");
1117 uasm_resolve_relocs(relocs, labels);
1118 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1119 (unsigned int)(p - handle_tlbl));
1121 dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1124 static void __cpuinit build_r3000_tlb_store_handler(void)
1126 u32 *p = handle_tlbs;
1127 struct uasm_label *l = labels;
1128 struct uasm_reloc *r = relocs;
1130 memset(handle_tlbs, 0, sizeof(handle_tlbs));
1131 memset(labels, 0, sizeof(labels));
1132 memset(relocs, 0, sizeof(relocs));
1134 build_r3000_tlbchange_handler_head(&p, K0, K1);
1135 build_pte_writable(&p, &r, K0, K1, label_nopage_tlbs);
1136 uasm_i_nop(&p); /* load delay */
1137 build_make_write(&p, &r, K0, K1);
1138 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1140 uasm_l_nopage_tlbs(&l, p);
1141 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1144 if ((p - handle_tlbs) > FASTPATH_SIZE)
1145 panic("TLB store handler fastpath space exceeded");
1147 uasm_resolve_relocs(relocs, labels);
1148 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1149 (unsigned int)(p - handle_tlbs));
1151 dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1154 static void __cpuinit build_r3000_tlb_modify_handler(void)
1156 u32 *p = handle_tlbm;
1157 struct uasm_label *l = labels;
1158 struct uasm_reloc *r = relocs;
1160 memset(handle_tlbm, 0, sizeof(handle_tlbm));
1161 memset(labels, 0, sizeof(labels));
1162 memset(relocs, 0, sizeof(relocs));
1164 build_r3000_tlbchange_handler_head(&p, K0, K1);
1165 build_pte_modifiable(&p, &r, K0, K1, label_nopage_tlbm);
1166 uasm_i_nop(&p); /* load delay */
1167 build_make_write(&p, &r, K0, K1);
1168 build_r3000_pte_reload_tlbwi(&p, K0, K1);
1170 uasm_l_nopage_tlbm(&l, p);
1171 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1174 if ((p - handle_tlbm) > FASTPATH_SIZE)
1175 panic("TLB modify handler fastpath space exceeded");
1177 uasm_resolve_relocs(relocs, labels);
1178 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1179 (unsigned int)(p - handle_tlbm));
1181 dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1185 * R4000 style TLB load/store/modify handlers.
1187 static void __cpuinit
1188 build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
1189 struct uasm_reloc **r, unsigned int pte,
1193 build_get_pmde64(p, l, r, pte, ptr); /* get pmd in ptr */
1195 build_get_pgde32(p, pte, ptr); /* get pgd in ptr */
1198 #ifdef CONFIG_HUGETLB_PAGE
1200 * For huge tlb entries, pmd doesn't contain an address but
1201 * instead contains the tlb pte. Check the PAGE_HUGE bit and
1202 * see if we need to jump to huge tlb processing.
1204 build_is_huge_pte(p, r, pte, ptr, label_tlb_huge_update);
1207 UASM_i_MFC0(p, pte, C0_BADVADDR);
1208 UASM_i_LW(p, ptr, 0, ptr);
1209 UASM_i_SRL(p, pte, pte, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
1210 uasm_i_andi(p, pte, pte, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
1211 UASM_i_ADDU(p, ptr, ptr, pte);
1214 uasm_l_smp_pgtable_change(l, *p);
1216 iPTE_LW(p, pte, ptr); /* get even pte */
1217 if (!m4kc_tlbp_war())
1218 build_tlb_probe_entry(p);
1221 static void __cpuinit
1222 build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
1223 struct uasm_reloc **r, unsigned int tmp,
1226 uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
1227 uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
1228 build_update_entries(p, tmp, ptr);
1229 build_tlb_write_entry(p, l, r, tlb_indexed);
1230 uasm_l_leave(l, *p);
1231 uasm_i_eret(p); /* return from trap */
1234 build_get_pgd_vmalloc64(p, l, r, tmp, ptr);
1238 static void __cpuinit build_r4000_tlb_load_handler(void)
1240 u32 *p = handle_tlbl;
1241 struct uasm_label *l = labels;
1242 struct uasm_reloc *r = relocs;
1244 memset(handle_tlbl, 0, sizeof(handle_tlbl));
1245 memset(labels, 0, sizeof(labels));
1246 memset(relocs, 0, sizeof(relocs));
1248 if (bcm1250_m3_war()) {
1249 UASM_i_MFC0(&p, K0, C0_BADVADDR);
1250 UASM_i_MFC0(&p, K1, C0_ENTRYHI);
1251 uasm_i_xor(&p, K0, K0, K1);
1252 UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
1253 uasm_il_bnez(&p, &r, K0, label_leave);
1254 /* No need for uasm_i_nop */
1257 build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1258 build_pte_present(&p, &r, K0, K1, label_nopage_tlbl);
1259 if (m4kc_tlbp_war())
1260 build_tlb_probe_entry(&p);
1261 build_make_valid(&p, &r, K0, K1);
1262 build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1264 #ifdef CONFIG_HUGETLB_PAGE
1266 * This is the entry point when build_r4000_tlbchange_handler_head
1267 * spots a huge page.
1269 uasm_l_tlb_huge_update(&l, p);
1270 iPTE_LW(&p, K0, K1);
1271 build_pte_present(&p, &r, K0, K1, label_nopage_tlbl);
1272 build_tlb_probe_entry(&p);
1273 uasm_i_ori(&p, K0, K0, (_PAGE_ACCESSED | _PAGE_VALID));
1274 build_huge_handler_tail(&p, &r, &l, K0, K1);
1277 uasm_l_nopage_tlbl(&l, p);
1278 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1281 if ((p - handle_tlbl) > FASTPATH_SIZE)
1282 panic("TLB load handler fastpath space exceeded");
1284 uasm_resolve_relocs(relocs, labels);
1285 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1286 (unsigned int)(p - handle_tlbl));
1288 dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1291 static void __cpuinit build_r4000_tlb_store_handler(void)
1293 u32 *p = handle_tlbs;
1294 struct uasm_label *l = labels;
1295 struct uasm_reloc *r = relocs;
1297 memset(handle_tlbs, 0, sizeof(handle_tlbs));
1298 memset(labels, 0, sizeof(labels));
1299 memset(relocs, 0, sizeof(relocs));
1301 build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1302 build_pte_writable(&p, &r, K0, K1, label_nopage_tlbs);
1303 if (m4kc_tlbp_war())
1304 build_tlb_probe_entry(&p);
1305 build_make_write(&p, &r, K0, K1);
1306 build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1308 #ifdef CONFIG_HUGETLB_PAGE
1310 * This is the entry point when
1311 * build_r4000_tlbchange_handler_head spots a huge page.
1313 uasm_l_tlb_huge_update(&l, p);
1314 iPTE_LW(&p, K0, K1);
1315 build_pte_writable(&p, &r, K0, K1, label_nopage_tlbs);
1316 build_tlb_probe_entry(&p);
1317 uasm_i_ori(&p, K0, K0,
1318 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
1319 build_huge_handler_tail(&p, &r, &l, K0, K1);
1322 uasm_l_nopage_tlbs(&l, p);
1323 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1326 if ((p - handle_tlbs) > FASTPATH_SIZE)
1327 panic("TLB store handler fastpath space exceeded");
1329 uasm_resolve_relocs(relocs, labels);
1330 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1331 (unsigned int)(p - handle_tlbs));
1333 dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1336 static void __cpuinit build_r4000_tlb_modify_handler(void)
1338 u32 *p = handle_tlbm;
1339 struct uasm_label *l = labels;
1340 struct uasm_reloc *r = relocs;
1342 memset(handle_tlbm, 0, sizeof(handle_tlbm));
1343 memset(labels, 0, sizeof(labels));
1344 memset(relocs, 0, sizeof(relocs));
1346 build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1347 build_pte_modifiable(&p, &r, K0, K1, label_nopage_tlbm);
1348 if (m4kc_tlbp_war())
1349 build_tlb_probe_entry(&p);
1350 /* Present and writable bits set, set accessed and dirty bits. */
1351 build_make_write(&p, &r, K0, K1);
1352 build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1354 #ifdef CONFIG_HUGETLB_PAGE
1356 * This is the entry point when
1357 * build_r4000_tlbchange_handler_head spots a huge page.
1359 uasm_l_tlb_huge_update(&l, p);
1360 iPTE_LW(&p, K0, K1);
1361 build_pte_modifiable(&p, &r, K0, K1, label_nopage_tlbm);
1362 build_tlb_probe_entry(&p);
1363 uasm_i_ori(&p, K0, K0,
1364 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
1365 build_huge_handler_tail(&p, &r, &l, K0, K1);
1368 uasm_l_nopage_tlbm(&l, p);
1369 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1372 if ((p - handle_tlbm) > FASTPATH_SIZE)
1373 panic("TLB modify handler fastpath space exceeded");
1375 uasm_resolve_relocs(relocs, labels);
1376 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1377 (unsigned int)(p - handle_tlbm));
1379 dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1382 void __cpuinit build_tlb_refill_handler(void)
1385 * The refill handler is generated per-CPU, multi-node systems
1386 * may have local storage for it. The other handlers are only
1389 static int run_once = 0;
1391 switch (current_cpu_type()) {
1399 build_r3000_tlb_refill_handler();
1401 build_r3000_tlb_load_handler();
1402 build_r3000_tlb_store_handler();
1403 build_r3000_tlb_modify_handler();
1410 panic("No R6000 TLB refill handler yet");
1414 panic("No R8000 TLB refill handler yet");
1418 build_r4000_tlb_refill_handler();
1420 build_r4000_tlb_load_handler();
1421 build_r4000_tlb_store_handler();
1422 build_r4000_tlb_modify_handler();
1428 void __cpuinit flush_tlb_handlers(void)
1430 local_flush_icache_range((unsigned long)handle_tlbl,
1431 (unsigned long)handle_tlbl + sizeof(handle_tlbl));
1432 local_flush_icache_range((unsigned long)handle_tlbs,
1433 (unsigned long)handle_tlbs + sizeof(handle_tlbs));
1434 local_flush_icache_range((unsigned long)handle_tlbm,
1435 (unsigned long)handle_tlbm + sizeof(handle_tlbm));