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);
336 uasm_i_nop(p); /* QED specifies 2 nops hazard */
338 * This branch uses up a mtc0 hazard nop slot and saves
339 * a nop after the tlbw instruction.
341 uasm_il_bgezl(p, r, 0, label_tlbw_hazard);
343 uasm_l_tlbw_hazard(l, *p);
356 * When the JTLB is updated by tlbwi or tlbwr, a subsequent
357 * use of the JTLB for instructions should not occur for 4
358 * cpu cycles and use for data translations should not occur
393 panic("No TLB refill handler yet (CPU type: %d)",
394 current_cpu_data.cputype);
399 #ifdef CONFIG_HUGETLB_PAGE
400 static __cpuinit void build_huge_tlb_write_entry(u32 **p,
401 struct uasm_label **l,
402 struct uasm_reloc **r,
404 enum tlb_write_entry wmode)
406 /* Set huge page tlb entry size */
407 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
408 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
409 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
411 build_tlb_write_entry(p, l, r, wmode);
413 /* Reset default page size */
414 if (PM_DEFAULT_MASK >> 16) {
415 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
416 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
417 uasm_il_b(p, r, label_leave);
418 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
419 } else if (PM_DEFAULT_MASK) {
420 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
421 uasm_il_b(p, r, label_leave);
422 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
424 uasm_il_b(p, r, label_leave);
425 uasm_i_mtc0(p, 0, C0_PAGEMASK);
430 * Check if Huge PTE is present, if so then jump to LABEL.
432 static void __cpuinit
433 build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
434 unsigned int pmd, int lid)
436 UASM_i_LW(p, tmp, 0, pmd);
437 uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
438 uasm_il_bnez(p, r, tmp, lid);
441 static __cpuinit void build_huge_update_entries(u32 **p,
448 * A huge PTE describes an area the size of the
449 * configured huge page size. This is twice the
450 * of the large TLB entry size we intend to use.
451 * A TLB entry half the size of the configured
452 * huge page size is configured into entrylo0
453 * and entrylo1 to cover the contiguous huge PTE
456 small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
458 /* We can clobber tmp. It isn't used after this.*/
460 uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
462 UASM_i_SRL(p, pte, pte, 6); /* convert to entrylo */
463 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* load it */
464 /* convert to entrylo1 */
466 UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
468 UASM_i_ADDU(p, pte, pte, tmp);
470 uasm_i_mtc0(p, pte, C0_ENTRYLO1); /* load it */
473 static __cpuinit void build_huge_handler_tail(u32 **p,
474 struct uasm_reloc **r,
475 struct uasm_label **l,
480 UASM_i_SC(p, pte, 0, ptr);
481 uasm_il_beqz(p, r, pte, label_tlb_huge_update);
482 UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
484 UASM_i_SW(p, pte, 0, ptr);
486 build_huge_update_entries(p, pte, ptr);
487 build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed);
489 #endif /* CONFIG_HUGETLB_PAGE */
493 * TMP and PTR are scratch.
494 * TMP will be clobbered, PTR will hold the pmd entry.
496 static void __cpuinit
497 build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
498 unsigned int tmp, unsigned int ptr)
500 long pgdc = (long)pgd_current;
503 * The vmalloc handling is not in the hotpath.
505 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
506 uasm_il_bltz(p, r, tmp, label_vmalloc);
507 /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
510 # ifdef CONFIG_MIPS_MT_SMTC
512 * SMTC uses TCBind value as "CPU" index
514 uasm_i_mfc0(p, ptr, C0_TCBIND);
515 uasm_i_dsrl(p, ptr, ptr, 19);
518 * 64 bit SMP running in XKPHYS has smp_processor_id() << 3
521 uasm_i_dmfc0(p, ptr, C0_CONTEXT);
522 uasm_i_dsrl(p, ptr, ptr, 23);
524 UASM_i_LA_mostly(p, tmp, pgdc);
525 uasm_i_daddu(p, ptr, ptr, tmp);
526 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
527 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
529 UASM_i_LA_mostly(p, ptr, pgdc);
530 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
533 uasm_l_vmalloc_done(l, *p);
535 if (PGDIR_SHIFT - 3 < 32) /* get pgd offset in bytes */
536 uasm_i_dsrl(p, tmp, tmp, PGDIR_SHIFT-3);
538 uasm_i_dsrl32(p, tmp, tmp, PGDIR_SHIFT - 3 - 32);
540 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
541 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
542 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
543 uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
544 uasm_i_dsrl(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
545 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
546 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
550 * BVADDR is the faulting address, PTR is scratch.
551 * PTR will hold the pgd for vmalloc.
553 static void __cpuinit
554 build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
555 unsigned int bvaddr, unsigned int ptr)
557 long swpd = (long)swapper_pg_dir;
559 uasm_l_vmalloc(l, *p);
561 if (uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd)) {
562 uasm_il_b(p, r, label_vmalloc_done);
563 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
565 UASM_i_LA_mostly(p, ptr, swpd);
566 uasm_il_b(p, r, label_vmalloc_done);
567 if (uasm_in_compat_space_p(swpd))
568 uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
570 uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
574 #else /* !CONFIG_64BIT */
577 * TMP and PTR are scratch.
578 * TMP will be clobbered, PTR will hold the pgd entry.
580 static void __cpuinit __maybe_unused
581 build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
583 long pgdc = (long)pgd_current;
585 /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
587 #ifdef CONFIG_MIPS_MT_SMTC
589 * SMTC uses TCBind value as "CPU" index
591 uasm_i_mfc0(p, ptr, C0_TCBIND);
592 UASM_i_LA_mostly(p, tmp, pgdc);
593 uasm_i_srl(p, ptr, ptr, 19);
596 * smp_processor_id() << 3 is stored in CONTEXT.
598 uasm_i_mfc0(p, ptr, C0_CONTEXT);
599 UASM_i_LA_mostly(p, tmp, pgdc);
600 uasm_i_srl(p, ptr, ptr, 23);
602 uasm_i_addu(p, ptr, tmp, ptr);
604 UASM_i_LA_mostly(p, ptr, pgdc);
606 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
607 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
608 uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
609 uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
610 uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
613 #endif /* !CONFIG_64BIT */
615 static void __cpuinit build_adjust_context(u32 **p, unsigned int ctx)
617 unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
618 unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
620 switch (current_cpu_type()) {
637 UASM_i_SRL(p, ctx, ctx, shift);
638 uasm_i_andi(p, ctx, ctx, mask);
641 static void __cpuinit build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
644 * Bug workaround for the Nevada. It seems as if under certain
645 * circumstances the move from cp0_context might produce a
646 * bogus result when the mfc0 instruction and its consumer are
647 * in a different cacheline or a load instruction, probably any
648 * memory reference, is between them.
650 switch (current_cpu_type()) {
652 UASM_i_LW(p, ptr, 0, ptr);
653 GET_CONTEXT(p, tmp); /* get context reg */
657 GET_CONTEXT(p, tmp); /* get context reg */
658 UASM_i_LW(p, ptr, 0, ptr);
662 build_adjust_context(p, tmp);
663 UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
666 static void __cpuinit build_update_entries(u32 **p, unsigned int tmp,
670 * 64bit address support (36bit on a 32bit CPU) in a 32bit
671 * Kernel is a special case. Only a few CPUs use it.
673 #ifdef CONFIG_64BIT_PHYS_ADDR
674 if (cpu_has_64bits) {
675 uasm_i_ld(p, tmp, 0, ptep); /* get even pte */
676 uasm_i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
677 uasm_i_dsrl(p, tmp, tmp, 6); /* convert to entrylo0 */
678 uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
679 uasm_i_dsrl(p, ptep, ptep, 6); /* convert to entrylo1 */
680 uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
682 int pte_off_even = sizeof(pte_t) / 2;
683 int pte_off_odd = pte_off_even + sizeof(pte_t);
685 /* The pte entries are pre-shifted */
686 uasm_i_lw(p, tmp, pte_off_even, ptep); /* get even pte */
687 uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
688 uasm_i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */
689 uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
692 UASM_i_LW(p, tmp, 0, ptep); /* get even pte */
693 UASM_i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */
695 build_tlb_probe_entry(p);
696 UASM_i_SRL(p, tmp, tmp, 6); /* convert to entrylo0 */
697 if (r4k_250MHZhwbug())
698 uasm_i_mtc0(p, 0, C0_ENTRYLO0);
699 uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */
700 UASM_i_SRL(p, ptep, ptep, 6); /* convert to entrylo1 */
702 uasm_i_mfc0(p, tmp, C0_INDEX);
703 if (r4k_250MHZhwbug())
704 uasm_i_mtc0(p, 0, C0_ENTRYLO1);
705 uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */
710 * For a 64-bit kernel, we are using the 64-bit XTLB refill exception
711 * because EXL == 0. If we wrap, we can also use the 32 instruction
712 * slots before the XTLB refill exception handler which belong to the
713 * unused TLB refill exception.
715 #define MIPS64_REFILL_INSNS 32
717 static void __cpuinit build_r4000_tlb_refill_handler(void)
719 u32 *p = tlb_handler;
720 struct uasm_label *l = labels;
721 struct uasm_reloc *r = relocs;
723 unsigned int final_len;
725 memset(tlb_handler, 0, sizeof(tlb_handler));
726 memset(labels, 0, sizeof(labels));
727 memset(relocs, 0, sizeof(relocs));
728 memset(final_handler, 0, sizeof(final_handler));
731 * create the plain linear handler
733 if (bcm1250_m3_war()) {
734 UASM_i_MFC0(&p, K0, C0_BADVADDR);
735 UASM_i_MFC0(&p, K1, C0_ENTRYHI);
736 uasm_i_xor(&p, K0, K0, K1);
737 UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
738 uasm_il_bnez(&p, &r, K0, label_leave);
739 /* No need for uasm_i_nop */
743 build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
745 build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
748 #ifdef CONFIG_HUGETLB_PAGE
749 build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
752 build_get_ptep(&p, K0, K1);
753 build_update_entries(&p, K0, K1);
754 build_tlb_write_entry(&p, &l, &r, tlb_random);
756 uasm_i_eret(&p); /* return from trap */
758 #ifdef CONFIG_HUGETLB_PAGE
759 uasm_l_tlb_huge_update(&l, p);
760 UASM_i_LW(&p, K0, 0, K1);
761 build_huge_update_entries(&p, K0, K1);
762 build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random);
766 build_get_pgd_vmalloc64(&p, &l, &r, K0, K1);
770 * Overflow check: For the 64bit handler, we need at least one
771 * free instruction slot for the wrap-around branch. In worst
772 * case, if the intended insertion point is a delay slot, we
773 * need three, with the second nop'ed and the third being
776 /* Loongson2 ebase is different than r4k, we have more space */
777 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
778 if ((p - tlb_handler) > 64)
779 panic("TLB refill handler space exceeded");
781 if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
782 || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
783 && uasm_insn_has_bdelay(relocs,
784 tlb_handler + MIPS64_REFILL_INSNS - 3)))
785 panic("TLB refill handler space exceeded");
789 * Now fold the handler in the TLB refill handler space.
791 #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2)
793 /* Simplest case, just copy the handler. */
794 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
795 final_len = p - tlb_handler;
796 #else /* CONFIG_64BIT */
797 f = final_handler + MIPS64_REFILL_INSNS;
798 if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
799 /* Just copy the handler. */
800 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
801 final_len = p - tlb_handler;
803 #if defined(CONFIG_HUGETLB_PAGE)
804 const enum label_id ls = label_tlb_huge_update;
805 #elif defined(MODULE_START)
806 const enum label_id ls = label_module_alloc;
808 const enum label_id ls = label_vmalloc;
814 for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
816 BUG_ON(i == ARRAY_SIZE(labels));
817 split = labels[i].addr;
820 * See if we have overflown one way or the other.
822 if (split > tlb_handler + MIPS64_REFILL_INSNS ||
823 split < p - MIPS64_REFILL_INSNS)
828 * Split two instructions before the end. One
829 * for the branch and one for the instruction
832 split = tlb_handler + MIPS64_REFILL_INSNS - 2;
835 * If the branch would fall in a delay slot,
836 * we must back up an additional instruction
837 * so that it is no longer in a delay slot.
839 if (uasm_insn_has_bdelay(relocs, split - 1))
842 /* Copy first part of the handler. */
843 uasm_copy_handler(relocs, labels, tlb_handler, split, f);
844 f += split - tlb_handler;
848 uasm_l_split(&l, final_handler);
849 uasm_il_b(&f, &r, label_split);
850 if (uasm_insn_has_bdelay(relocs, split))
853 uasm_copy_handler(relocs, labels,
854 split, split + 1, f);
855 uasm_move_labels(labels, f, f + 1, -1);
861 /* Copy the rest of the handler. */
862 uasm_copy_handler(relocs, labels, split, p, final_handler);
863 final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
866 #endif /* CONFIG_64BIT */
868 uasm_resolve_relocs(relocs, labels);
869 pr_debug("Wrote TLB refill handler (%u instructions).\n",
872 memcpy((void *)ebase, final_handler, 0x100);
874 dump_handler((u32 *)ebase, 64);
878 * TLB load/store/modify handlers.
880 * Only the fastpath gets synthesized at runtime, the slowpath for
881 * do_page_fault remains normal asm.
883 extern void tlb_do_page_fault_0(void);
884 extern void tlb_do_page_fault_1(void);
887 * 128 instructions for the fastpath handler is generous and should
890 #define FASTPATH_SIZE 128
892 u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned;
893 u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned;
894 u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned;
896 static void __cpuinit
897 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
900 # ifdef CONFIG_64BIT_PHYS_ADDR
902 uasm_i_lld(p, pte, 0, ptr);
905 UASM_i_LL(p, pte, 0, ptr);
907 # ifdef CONFIG_64BIT_PHYS_ADDR
909 uasm_i_ld(p, pte, 0, ptr);
912 UASM_i_LW(p, pte, 0, ptr);
916 static void __cpuinit
917 iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
920 #ifdef CONFIG_64BIT_PHYS_ADDR
921 unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
924 uasm_i_ori(p, pte, pte, mode);
926 # ifdef CONFIG_64BIT_PHYS_ADDR
928 uasm_i_scd(p, pte, 0, ptr);
931 UASM_i_SC(p, pte, 0, ptr);
933 if (r10000_llsc_war())
934 uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
936 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
938 # ifdef CONFIG_64BIT_PHYS_ADDR
939 if (!cpu_has_64bits) {
940 /* no uasm_i_nop needed */
941 uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
942 uasm_i_ori(p, pte, pte, hwmode);
943 uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
944 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
945 /* no uasm_i_nop needed */
946 uasm_i_lw(p, pte, 0, ptr);
953 # ifdef CONFIG_64BIT_PHYS_ADDR
955 uasm_i_sd(p, pte, 0, ptr);
958 UASM_i_SW(p, pte, 0, ptr);
960 # ifdef CONFIG_64BIT_PHYS_ADDR
961 if (!cpu_has_64bits) {
962 uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
963 uasm_i_ori(p, pte, pte, hwmode);
964 uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
965 uasm_i_lw(p, pte, 0, ptr);
972 * Check if PTE is present, if not then jump to LABEL. PTR points to
973 * the page table where this PTE is located, PTE will be re-loaded
974 * with it's original value.
976 static void __cpuinit
977 build_pte_present(u32 **p, struct uasm_reloc **r,
978 unsigned int pte, unsigned int ptr, enum label_id lid)
980 uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
981 uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_READ);
982 uasm_il_bnez(p, r, pte, lid);
983 iPTE_LW(p, pte, ptr);
986 /* Make PTE valid, store result in PTR. */
987 static void __cpuinit
988 build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
991 unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
993 iPTE_SW(p, r, pte, ptr, mode);
997 * Check if PTE can be written to, if not branch to LABEL. Regardless
998 * restore PTE with value from PTR when done.
1000 static void __cpuinit
1001 build_pte_writable(u32 **p, struct uasm_reloc **r,
1002 unsigned int pte, unsigned int ptr, enum label_id lid)
1004 uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1005 uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE);
1006 uasm_il_bnez(p, r, pte, lid);
1007 iPTE_LW(p, pte, ptr);
1010 /* Make PTE writable, update software status bits as well, then store
1013 static void __cpuinit
1014 build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
1017 unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1020 iPTE_SW(p, r, pte, ptr, mode);
1024 * Check if PTE can be modified, if not branch to LABEL. Regardless
1025 * restore PTE with value from PTR when done.
1027 static void __cpuinit
1028 build_pte_modifiable(u32 **p, struct uasm_reloc **r,
1029 unsigned int pte, unsigned int ptr, enum label_id lid)
1031 uasm_i_andi(p, pte, pte, _PAGE_WRITE);
1032 uasm_il_beqz(p, r, pte, lid);
1033 iPTE_LW(p, pte, ptr);
1037 * R3000 style TLB load/store/modify handlers.
1041 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1044 static void __cpuinit
1045 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1047 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1048 uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1051 uasm_i_rfe(p); /* branch delay */
1055 * This places the pte into ENTRYLO0 and writes it with tlbwi
1056 * or tlbwr as appropriate. This is because the index register
1057 * may have the probe fail bit set as a result of a trap on a
1058 * kseg2 access, i.e. without refill. Then it returns.
1060 static void __cpuinit
1061 build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
1062 struct uasm_reloc **r, unsigned int pte,
1065 uasm_i_mfc0(p, tmp, C0_INDEX);
1066 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1067 uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1068 uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
1069 uasm_i_tlbwi(p); /* cp0 delay */
1071 uasm_i_rfe(p); /* branch delay */
1072 uasm_l_r3000_write_probe_fail(l, *p);
1073 uasm_i_tlbwr(p); /* cp0 delay */
1075 uasm_i_rfe(p); /* branch delay */
1078 static void __cpuinit
1079 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1082 long pgdc = (long)pgd_current;
1084 uasm_i_mfc0(p, pte, C0_BADVADDR);
1085 uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
1086 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
1087 uasm_i_srl(p, pte, pte, 22); /* load delay */
1088 uasm_i_sll(p, pte, pte, 2);
1089 uasm_i_addu(p, ptr, ptr, pte);
1090 uasm_i_mfc0(p, pte, C0_CONTEXT);
1091 uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
1092 uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
1093 uasm_i_addu(p, ptr, ptr, pte);
1094 uasm_i_lw(p, pte, 0, ptr);
1095 uasm_i_tlbp(p); /* load delay */
1098 static void __cpuinit build_r3000_tlb_load_handler(void)
1100 u32 *p = handle_tlbl;
1101 struct uasm_label *l = labels;
1102 struct uasm_reloc *r = relocs;
1104 memset(handle_tlbl, 0, sizeof(handle_tlbl));
1105 memset(labels, 0, sizeof(labels));
1106 memset(relocs, 0, sizeof(relocs));
1108 build_r3000_tlbchange_handler_head(&p, K0, K1);
1109 build_pte_present(&p, &r, K0, K1, label_nopage_tlbl);
1110 uasm_i_nop(&p); /* load delay */
1111 build_make_valid(&p, &r, K0, K1);
1112 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1114 uasm_l_nopage_tlbl(&l, p);
1115 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1118 if ((p - handle_tlbl) > FASTPATH_SIZE)
1119 panic("TLB load handler fastpath space exceeded");
1121 uasm_resolve_relocs(relocs, labels);
1122 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1123 (unsigned int)(p - handle_tlbl));
1125 dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1128 static void __cpuinit build_r3000_tlb_store_handler(void)
1130 u32 *p = handle_tlbs;
1131 struct uasm_label *l = labels;
1132 struct uasm_reloc *r = relocs;
1134 memset(handle_tlbs, 0, sizeof(handle_tlbs));
1135 memset(labels, 0, sizeof(labels));
1136 memset(relocs, 0, sizeof(relocs));
1138 build_r3000_tlbchange_handler_head(&p, K0, K1);
1139 build_pte_writable(&p, &r, K0, K1, label_nopage_tlbs);
1140 uasm_i_nop(&p); /* load delay */
1141 build_make_write(&p, &r, K0, K1);
1142 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1144 uasm_l_nopage_tlbs(&l, p);
1145 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1148 if ((p - handle_tlbs) > FASTPATH_SIZE)
1149 panic("TLB store handler fastpath space exceeded");
1151 uasm_resolve_relocs(relocs, labels);
1152 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1153 (unsigned int)(p - handle_tlbs));
1155 dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1158 static void __cpuinit build_r3000_tlb_modify_handler(void)
1160 u32 *p = handle_tlbm;
1161 struct uasm_label *l = labels;
1162 struct uasm_reloc *r = relocs;
1164 memset(handle_tlbm, 0, sizeof(handle_tlbm));
1165 memset(labels, 0, sizeof(labels));
1166 memset(relocs, 0, sizeof(relocs));
1168 build_r3000_tlbchange_handler_head(&p, K0, K1);
1169 build_pte_modifiable(&p, &r, K0, K1, label_nopage_tlbm);
1170 uasm_i_nop(&p); /* load delay */
1171 build_make_write(&p, &r, K0, K1);
1172 build_r3000_pte_reload_tlbwi(&p, K0, K1);
1174 uasm_l_nopage_tlbm(&l, p);
1175 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1178 if ((p - handle_tlbm) > FASTPATH_SIZE)
1179 panic("TLB modify handler fastpath space exceeded");
1181 uasm_resolve_relocs(relocs, labels);
1182 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1183 (unsigned int)(p - handle_tlbm));
1185 dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1189 * R4000 style TLB load/store/modify handlers.
1191 static void __cpuinit
1192 build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
1193 struct uasm_reloc **r, unsigned int pte,
1197 build_get_pmde64(p, l, r, pte, ptr); /* get pmd in ptr */
1199 build_get_pgde32(p, pte, ptr); /* get pgd in ptr */
1202 #ifdef CONFIG_HUGETLB_PAGE
1204 * For huge tlb entries, pmd doesn't contain an address but
1205 * instead contains the tlb pte. Check the PAGE_HUGE bit and
1206 * see if we need to jump to huge tlb processing.
1208 build_is_huge_pte(p, r, pte, ptr, label_tlb_huge_update);
1211 UASM_i_MFC0(p, pte, C0_BADVADDR);
1212 UASM_i_LW(p, ptr, 0, ptr);
1213 UASM_i_SRL(p, pte, pte, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
1214 uasm_i_andi(p, pte, pte, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
1215 UASM_i_ADDU(p, ptr, ptr, pte);
1218 uasm_l_smp_pgtable_change(l, *p);
1220 iPTE_LW(p, pte, ptr); /* get even pte */
1221 if (!m4kc_tlbp_war())
1222 build_tlb_probe_entry(p);
1225 static void __cpuinit
1226 build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
1227 struct uasm_reloc **r, unsigned int tmp,
1230 uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
1231 uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
1232 build_update_entries(p, tmp, ptr);
1233 build_tlb_write_entry(p, l, r, tlb_indexed);
1234 uasm_l_leave(l, *p);
1235 uasm_i_eret(p); /* return from trap */
1238 build_get_pgd_vmalloc64(p, l, r, tmp, ptr);
1242 static void __cpuinit build_r4000_tlb_load_handler(void)
1244 u32 *p = handle_tlbl;
1245 struct uasm_label *l = labels;
1246 struct uasm_reloc *r = relocs;
1248 memset(handle_tlbl, 0, sizeof(handle_tlbl));
1249 memset(labels, 0, sizeof(labels));
1250 memset(relocs, 0, sizeof(relocs));
1252 if (bcm1250_m3_war()) {
1253 UASM_i_MFC0(&p, K0, C0_BADVADDR);
1254 UASM_i_MFC0(&p, K1, C0_ENTRYHI);
1255 uasm_i_xor(&p, K0, K0, K1);
1256 UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
1257 uasm_il_bnez(&p, &r, K0, label_leave);
1258 /* No need for uasm_i_nop */
1261 build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1262 build_pte_present(&p, &r, K0, K1, label_nopage_tlbl);
1263 if (m4kc_tlbp_war())
1264 build_tlb_probe_entry(&p);
1265 build_make_valid(&p, &r, K0, K1);
1266 build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1268 #ifdef CONFIG_HUGETLB_PAGE
1270 * This is the entry point when build_r4000_tlbchange_handler_head
1271 * spots a huge page.
1273 uasm_l_tlb_huge_update(&l, p);
1274 iPTE_LW(&p, K0, K1);
1275 build_pte_present(&p, &r, K0, K1, label_nopage_tlbl);
1276 build_tlb_probe_entry(&p);
1277 uasm_i_ori(&p, K0, K0, (_PAGE_ACCESSED | _PAGE_VALID));
1278 build_huge_handler_tail(&p, &r, &l, K0, K1);
1281 uasm_l_nopage_tlbl(&l, p);
1282 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1285 if ((p - handle_tlbl) > FASTPATH_SIZE)
1286 panic("TLB load handler fastpath space exceeded");
1288 uasm_resolve_relocs(relocs, labels);
1289 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1290 (unsigned int)(p - handle_tlbl));
1292 dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl));
1295 static void __cpuinit build_r4000_tlb_store_handler(void)
1297 u32 *p = handle_tlbs;
1298 struct uasm_label *l = labels;
1299 struct uasm_reloc *r = relocs;
1301 memset(handle_tlbs, 0, sizeof(handle_tlbs));
1302 memset(labels, 0, sizeof(labels));
1303 memset(relocs, 0, sizeof(relocs));
1305 build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1306 build_pte_writable(&p, &r, K0, K1, label_nopage_tlbs);
1307 if (m4kc_tlbp_war())
1308 build_tlb_probe_entry(&p);
1309 build_make_write(&p, &r, K0, K1);
1310 build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1312 #ifdef CONFIG_HUGETLB_PAGE
1314 * This is the entry point when
1315 * build_r4000_tlbchange_handler_head spots a huge page.
1317 uasm_l_tlb_huge_update(&l, p);
1318 iPTE_LW(&p, K0, K1);
1319 build_pte_writable(&p, &r, K0, K1, label_nopage_tlbs);
1320 build_tlb_probe_entry(&p);
1321 uasm_i_ori(&p, K0, K0,
1322 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
1323 build_huge_handler_tail(&p, &r, &l, K0, K1);
1326 uasm_l_nopage_tlbs(&l, p);
1327 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1330 if ((p - handle_tlbs) > FASTPATH_SIZE)
1331 panic("TLB store handler fastpath space exceeded");
1333 uasm_resolve_relocs(relocs, labels);
1334 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1335 (unsigned int)(p - handle_tlbs));
1337 dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs));
1340 static void __cpuinit build_r4000_tlb_modify_handler(void)
1342 u32 *p = handle_tlbm;
1343 struct uasm_label *l = labels;
1344 struct uasm_reloc *r = relocs;
1346 memset(handle_tlbm, 0, sizeof(handle_tlbm));
1347 memset(labels, 0, sizeof(labels));
1348 memset(relocs, 0, sizeof(relocs));
1350 build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1);
1351 build_pte_modifiable(&p, &r, K0, K1, label_nopage_tlbm);
1352 if (m4kc_tlbp_war())
1353 build_tlb_probe_entry(&p);
1354 /* Present and writable bits set, set accessed and dirty bits. */
1355 build_make_write(&p, &r, K0, K1);
1356 build_r4000_tlbchange_handler_tail(&p, &l, &r, K0, K1);
1358 #ifdef CONFIG_HUGETLB_PAGE
1360 * This is the entry point when
1361 * build_r4000_tlbchange_handler_head spots a huge page.
1363 uasm_l_tlb_huge_update(&l, p);
1364 iPTE_LW(&p, K0, K1);
1365 build_pte_modifiable(&p, &r, K0, K1, label_nopage_tlbm);
1366 build_tlb_probe_entry(&p);
1367 uasm_i_ori(&p, K0, K0,
1368 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
1369 build_huge_handler_tail(&p, &r, &l, K0, K1);
1372 uasm_l_nopage_tlbm(&l, p);
1373 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1376 if ((p - handle_tlbm) > FASTPATH_SIZE)
1377 panic("TLB modify handler fastpath space exceeded");
1379 uasm_resolve_relocs(relocs, labels);
1380 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1381 (unsigned int)(p - handle_tlbm));
1383 dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm));
1386 void __cpuinit build_tlb_refill_handler(void)
1389 * The refill handler is generated per-CPU, multi-node systems
1390 * may have local storage for it. The other handlers are only
1393 static int run_once = 0;
1395 switch (current_cpu_type()) {
1403 build_r3000_tlb_refill_handler();
1405 build_r3000_tlb_load_handler();
1406 build_r3000_tlb_store_handler();
1407 build_r3000_tlb_modify_handler();
1414 panic("No R6000 TLB refill handler yet");
1418 panic("No R8000 TLB refill handler yet");
1422 build_r4000_tlb_refill_handler();
1424 build_r4000_tlb_load_handler();
1425 build_r4000_tlb_store_handler();
1426 build_r4000_tlb_modify_handler();
1432 void __cpuinit flush_tlb_handlers(void)
1434 local_flush_icache_range((unsigned long)handle_tlbl,
1435 (unsigned long)handle_tlbl + sizeof(handle_tlbl));
1436 local_flush_icache_range((unsigned long)handle_tlbs,
1437 (unsigned long)handle_tlbs + sizeof(handle_tlbs));
1438 local_flush_icache_range((unsigned long)handle_tlbm,
1439 (unsigned long)handle_tlbm + sizeof(handle_tlbm));