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.
12 * Copyright (C) 2011 MIPS Technologies, Inc.
14 * ... and the days got worse and worse and now you see
15 * I've gone completely out of my mind.
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 ...
21 * (Condolences to Napoleon XIV)
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>
32 #include <asm/cacheflush.h>
33 #include <asm/cpu-type.h>
34 #include <asm/mmu_context.h>
35 #include <asm/pgtable.h>
38 #include <asm/setup.h>
39 #include <asm/tlbex.h>
41 static int mips_xpa_disabled;
43 static int __init xpa_disable(char *s)
45 mips_xpa_disabled = 1;
50 __setup("noxpa", xpa_disable);
53 * TLB load/store/modify handlers.
55 * Only the fastpath gets synthesized at runtime, the slowpath for
56 * do_page_fault remains normal asm.
58 extern void tlb_do_page_fault_0(void);
59 extern void tlb_do_page_fault_1(void);
61 struct work_registers {
70 } ____cacheline_aligned_in_smp;
72 static struct tlb_reg_save handler_reg_save[NR_CPUS];
74 static inline int r45k_bvahwbug(void)
76 /* XXX: We should probe for the presence of this bug, but we don't. */
80 static inline int r4k_250MHZhwbug(void)
82 /* XXX: We should probe for the presence of this bug, but we don't. */
86 static inline int __maybe_unused bcm1250_m3_war(void)
88 return BCM1250_M3_WAR;
91 static inline int __maybe_unused r10000_llsc_war(void)
93 return R10000_LLSC_WAR;
96 static int use_bbit_insns(void)
98 switch (current_cpu_type()) {
99 case CPU_CAVIUM_OCTEON:
100 case CPU_CAVIUM_OCTEON_PLUS:
101 case CPU_CAVIUM_OCTEON2:
102 case CPU_CAVIUM_OCTEON3:
109 static int use_lwx_insns(void)
111 switch (current_cpu_type()) {
112 case CPU_CAVIUM_OCTEON2:
113 case CPU_CAVIUM_OCTEON3:
119 #if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \
120 CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
121 static bool scratchpad_available(void)
125 static int scratchpad_offset(int i)
128 * CVMSEG starts at address -32768 and extends for
129 * CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines.
131 i += 1; /* Kernel use starts at the top and works down. */
132 return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768;
135 static bool scratchpad_available(void)
139 static int scratchpad_offset(int i)
142 /* Really unreachable, but evidently some GCC want this. */
147 * Found by experiment: At least some revisions of the 4kc throw under
148 * some circumstances a machine check exception, triggered by invalid
149 * values in the index register. Delaying the tlbp instruction until
150 * after the next branch, plus adding an additional nop in front of
151 * tlbwi/tlbwr avoids the invalid index register values. Nobody knows
152 * why; it's not an issue caused by the core RTL.
155 static int m4kc_tlbp_war(void)
157 return current_cpu_type() == CPU_4KC;
160 /* Handle labels (which must be positive integers). */
162 label_second_part = 1,
167 label_split = label_tlbw_hazard_0 + 8,
168 label_tlbl_goaround1,
169 label_tlbl_goaround2,
173 label_smp_pgtable_change,
174 label_r3000_write_probe_fail,
175 label_large_segbits_fault,
176 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
177 label_tlb_huge_update,
181 UASM_L_LA(_second_part)
184 UASM_L_LA(_vmalloc_done)
185 /* _tlbw_hazard_x is handled differently. */
187 UASM_L_LA(_tlbl_goaround1)
188 UASM_L_LA(_tlbl_goaround2)
189 UASM_L_LA(_nopage_tlbl)
190 UASM_L_LA(_nopage_tlbs)
191 UASM_L_LA(_nopage_tlbm)
192 UASM_L_LA(_smp_pgtable_change)
193 UASM_L_LA(_r3000_write_probe_fail)
194 UASM_L_LA(_large_segbits_fault)
195 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
196 UASM_L_LA(_tlb_huge_update)
199 static int hazard_instance;
201 static void uasm_bgezl_hazard(u32 **p, struct uasm_reloc **r, int instance)
205 uasm_il_bgezl(p, r, 0, label_tlbw_hazard_0 + instance);
212 static void uasm_bgezl_label(struct uasm_label **l, u32 **p, int instance)
216 uasm_build_label(l, *p, label_tlbw_hazard_0 + instance);
224 * pgtable bits are assigned dynamically depending on processor feature
225 * and statically based on kernel configuration. This spits out the actual
226 * values the kernel is using. Required to make sense from disassembled
227 * TLB exception handlers.
229 static void output_pgtable_bits_defines(void)
231 #define pr_define(fmt, ...) \
232 pr_debug("#define " fmt, ##__VA_ARGS__)
234 pr_debug("#include <asm/asm.h>\n");
235 pr_debug("#include <asm/regdef.h>\n");
238 pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT);
239 pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
240 pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
241 pr_define("_PAGE_ACCESSED_SHIFT %d\n", _PAGE_ACCESSED_SHIFT);
242 pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT);
243 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
244 pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT);
246 #ifdef _PAGE_NO_EXEC_SHIFT
248 pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
250 pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT);
251 pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT);
252 pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT);
253 pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
257 static inline void dump_handler(const char *symbol, const void *start, const void *end)
259 unsigned int count = (end - start) / sizeof(u32);
260 const u32 *handler = start;
263 pr_debug("LEAF(%s)\n", symbol);
265 pr_debug("\t.set push\n");
266 pr_debug("\t.set noreorder\n");
268 for (i = 0; i < count; i++)
269 pr_debug("\t.word\t0x%08x\t\t# %p\n", handler[i], &handler[i]);
271 pr_debug("\t.set\tpop\n");
273 pr_debug("\tEND(%s)\n", symbol);
276 /* The only general purpose registers allowed in TLB handlers. */
280 /* Some CP0 registers */
281 #define C0_INDEX 0, 0
282 #define C0_ENTRYLO0 2, 0
283 #define C0_TCBIND 2, 2
284 #define C0_ENTRYLO1 3, 0
285 #define C0_CONTEXT 4, 0
286 #define C0_PAGEMASK 5, 0
287 #define C0_PWBASE 5, 5
288 #define C0_PWFIELD 5, 6
289 #define C0_PWSIZE 5, 7
290 #define C0_PWCTL 6, 6
291 #define C0_BADVADDR 8, 0
293 #define C0_ENTRYHI 10, 0
295 #define C0_XCONTEXT 20, 0
298 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT)
300 # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT)
303 /* The worst case length of the handler is around 18 instructions for
304 * R3000-style TLBs and up to 63 instructions for R4000-style TLBs.
305 * Maximum space available is 32 instructions for R3000 and 64
306 * instructions for R4000.
308 * We deliberately chose a buffer size of 128, so we won't scribble
309 * over anything important on overflow before we panic.
311 static u32 tlb_handler[128];
313 /* simply assume worst case size for labels and relocs */
314 static struct uasm_label labels[128];
315 static struct uasm_reloc relocs[128];
317 static int check_for_high_segbits;
318 static bool fill_includes_sw_bits;
320 static unsigned int kscratch_used_mask;
322 static inline int __maybe_unused c0_kscratch(void)
324 switch (current_cpu_type()) {
333 static int allocate_kscratch(void)
336 unsigned int a = cpu_data[0].kscratch_mask & ~kscratch_used_mask;
343 r--; /* make it zero based */
345 kscratch_used_mask |= (1 << r);
350 static int scratch_reg;
352 EXPORT_SYMBOL_GPL(pgd_reg);
353 enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch};
355 static struct work_registers build_get_work_registers(u32 **p)
357 struct work_registers r;
359 if (scratch_reg >= 0) {
360 /* Save in CPU local C0_KScratch? */
361 UASM_i_MTC0(p, 1, c0_kscratch(), scratch_reg);
368 if (num_possible_cpus() > 1) {
369 /* Get smp_processor_id */
370 UASM_i_CPUID_MFC0(p, K0, SMP_CPUID_REG);
371 UASM_i_SRL_SAFE(p, K0, K0, SMP_CPUID_REGSHIFT);
373 /* handler_reg_save index in K0 */
374 UASM_i_SLL(p, K0, K0, ilog2(sizeof(struct tlb_reg_save)));
376 UASM_i_LA(p, K1, (long)&handler_reg_save);
377 UASM_i_ADDU(p, K0, K0, K1);
379 UASM_i_LA(p, K0, (long)&handler_reg_save);
381 /* K0 now points to save area, save $1 and $2 */
382 UASM_i_SW(p, 1, offsetof(struct tlb_reg_save, a), K0);
383 UASM_i_SW(p, 2, offsetof(struct tlb_reg_save, b), K0);
391 static void build_restore_work_registers(u32 **p)
393 if (scratch_reg >= 0) {
394 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
397 /* K0 already points to save area, restore $1 and $2 */
398 UASM_i_LW(p, 1, offsetof(struct tlb_reg_save, a), K0);
399 UASM_i_LW(p, 2, offsetof(struct tlb_reg_save, b), K0);
402 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
405 * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current,
406 * we cannot do r3000 under these circumstances.
408 * The R3000 TLB handler is simple.
410 static void build_r3000_tlb_refill_handler(void)
412 long pgdc = (long)pgd_current;
415 memset(tlb_handler, 0, sizeof(tlb_handler));
418 uasm_i_mfc0(&p, K0, C0_BADVADDR);
419 uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */
420 uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1);
421 uasm_i_srl(&p, K0, K0, 22); /* load delay */
422 uasm_i_sll(&p, K0, K0, 2);
423 uasm_i_addu(&p, K1, K1, K0);
424 uasm_i_mfc0(&p, K0, C0_CONTEXT);
425 uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */
426 uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */
427 uasm_i_addu(&p, K1, K1, K0);
428 uasm_i_lw(&p, K0, 0, K1);
429 uasm_i_nop(&p); /* load delay */
430 uasm_i_mtc0(&p, K0, C0_ENTRYLO0);
431 uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */
432 uasm_i_tlbwr(&p); /* cp0 delay */
434 uasm_i_rfe(&p); /* branch delay */
436 if (p > tlb_handler + 32)
437 panic("TLB refill handler space exceeded");
439 pr_debug("Wrote TLB refill handler (%u instructions).\n",
440 (unsigned int)(p - tlb_handler));
442 memcpy((void *)ebase, tlb_handler, 0x80);
443 local_flush_icache_range(ebase, ebase + 0x80);
444 dump_handler("r3000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x80));
446 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
449 * The R4000 TLB handler is much more complicated. We have two
450 * consecutive handler areas with 32 instructions space each.
451 * Since they aren't used at the same time, we can overflow in the
452 * other one.To keep things simple, we first assume linear space,
453 * then we relocate it to the final handler layout as needed.
455 static u32 final_handler[64];
460 * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0:
461 * 2. A timing hazard exists for the TLBP instruction.
463 * stalling_instruction
466 * The JTLB is being read for the TLBP throughout the stall generated by the
467 * previous instruction. This is not really correct as the stalling instruction
468 * can modify the address used to access the JTLB. The failure symptom is that
469 * the TLBP instruction will use an address created for the stalling instruction
470 * and not the address held in C0_ENHI and thus report the wrong results.
472 * The software work-around is to not allow the instruction preceding the TLBP
473 * to stall - make it an NOP or some other instruction guaranteed not to stall.
475 * Errata 2 will not be fixed. This errata is also on the R5000.
477 * As if we MIPS hackers wouldn't know how to nop pipelines happy ...
479 static void __maybe_unused build_tlb_probe_entry(u32 **p)
481 switch (current_cpu_type()) {
482 /* Found by experiment: R4600 v2.0/R4700 needs this, too. */
497 void build_tlb_write_entry(u32 **p, struct uasm_label **l,
498 struct uasm_reloc **r,
499 enum tlb_write_entry wmode)
501 void(*tlbw)(u32 **) = NULL;
504 case tlb_random: tlbw = uasm_i_tlbwr; break;
505 case tlb_indexed: tlbw = uasm_i_tlbwi; break;
508 if (cpu_has_mips_r2_r6) {
509 if (cpu_has_mips_r2_exec_hazard)
515 switch (current_cpu_type()) {
523 * This branch uses up a mtc0 hazard nop slot and saves
524 * two nops after the tlbw instruction.
526 uasm_bgezl_hazard(p, r, hazard_instance);
528 uasm_bgezl_label(l, p, hazard_instance);
542 uasm_i_nop(p); /* QED specifies 2 nops hazard */
543 uasm_i_nop(p); /* QED specifies 2 nops hazard */
618 panic("No TLB refill handler yet (CPU type: %d)",
623 EXPORT_SYMBOL_GPL(build_tlb_write_entry);
625 static __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
628 if (_PAGE_GLOBAL_SHIFT == 0) {
629 /* pte_t is already in EntryLo format */
633 if (cpu_has_rixi && _PAGE_NO_EXEC) {
634 if (fill_includes_sw_bits) {
635 UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
637 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_NO_EXEC));
638 UASM_i_ROTR(p, reg, reg,
639 ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
642 #ifdef CONFIG_PHYS_ADDR_T_64BIT
643 uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL));
645 UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL));
650 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
652 static void build_restore_pagemask(u32 **p, struct uasm_reloc **r,
653 unsigned int tmp, enum label_id lid,
656 if (restore_scratch) {
657 /* Reset default page size */
658 if (PM_DEFAULT_MASK >> 16) {
659 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
660 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
661 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
662 uasm_il_b(p, r, lid);
663 } else if (PM_DEFAULT_MASK) {
664 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
665 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
666 uasm_il_b(p, r, lid);
668 uasm_i_mtc0(p, 0, C0_PAGEMASK);
669 uasm_il_b(p, r, lid);
671 if (scratch_reg >= 0)
672 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
674 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
676 /* Reset default page size */
677 if (PM_DEFAULT_MASK >> 16) {
678 uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
679 uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
680 uasm_il_b(p, r, lid);
681 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
682 } else if (PM_DEFAULT_MASK) {
683 uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
684 uasm_il_b(p, r, lid);
685 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
687 uasm_il_b(p, r, lid);
688 uasm_i_mtc0(p, 0, C0_PAGEMASK);
693 static void build_huge_tlb_write_entry(u32 **p, struct uasm_label **l,
694 struct uasm_reloc **r,
696 enum tlb_write_entry wmode,
699 /* Set huge page tlb entry size */
700 uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
701 uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff);
702 uasm_i_mtc0(p, tmp, C0_PAGEMASK);
704 build_tlb_write_entry(p, l, r, wmode);
706 build_restore_pagemask(p, r, tmp, label_leave, restore_scratch);
710 * Check if Huge PTE is present, if so then jump to LABEL.
713 build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp,
714 unsigned int pmd, int lid)
716 UASM_i_LW(p, tmp, 0, pmd);
717 if (use_bbit_insns()) {
718 uasm_il_bbit1(p, r, tmp, ilog2(_PAGE_HUGE), lid);
720 uasm_i_andi(p, tmp, tmp, _PAGE_HUGE);
721 uasm_il_bnez(p, r, tmp, lid);
725 static void build_huge_update_entries(u32 **p, unsigned int pte,
731 * A huge PTE describes an area the size of the
732 * configured huge page size. This is twice the
733 * of the large TLB entry size we intend to use.
734 * A TLB entry half the size of the configured
735 * huge page size is configured into entrylo0
736 * and entrylo1 to cover the contiguous huge PTE
739 small_sequence = (HPAGE_SIZE >> 7) < 0x10000;
741 /* We can clobber tmp. It isn't used after this.*/
743 uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16));
745 build_convert_pte_to_entrylo(p, pte);
746 UASM_i_MTC0(p, pte, C0_ENTRYLO0); /* load it */
747 /* convert to entrylo1 */
749 UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7);
751 UASM_i_ADDU(p, pte, pte, tmp);
753 UASM_i_MTC0(p, pte, C0_ENTRYLO1); /* load it */
756 static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r,
757 struct uasm_label **l,
763 UASM_i_SC(p, pte, 0, ptr);
764 uasm_il_beqz(p, r, pte, label_tlb_huge_update);
765 UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */
767 UASM_i_SW(p, pte, 0, ptr);
769 if (cpu_has_ftlb && flush) {
770 BUG_ON(!cpu_has_tlbinv);
772 UASM_i_MFC0(p, ptr, C0_ENTRYHI);
773 uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
774 UASM_i_MTC0(p, ptr, C0_ENTRYHI);
775 build_tlb_write_entry(p, l, r, tlb_indexed);
777 uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
778 UASM_i_MTC0(p, ptr, C0_ENTRYHI);
779 build_huge_update_entries(p, pte, ptr);
780 build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0);
785 build_huge_update_entries(p, pte, ptr);
786 build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
788 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
792 * TMP and PTR are scratch.
793 * TMP will be clobbered, PTR will hold the pmd entry.
795 void build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
796 unsigned int tmp, unsigned int ptr)
798 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
799 long pgdc = (long)pgd_current;
802 * The vmalloc handling is not in the hotpath.
804 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
806 if (check_for_high_segbits) {
808 * The kernel currently implicitely assumes that the
809 * MIPS SEGBITS parameter for the processor is
810 * (PGDIR_SHIFT+PGDIR_BITS) or less, and will never
811 * allocate virtual addresses outside the maximum
812 * range for SEGBITS = (PGDIR_SHIFT+PGDIR_BITS). But
813 * that doesn't prevent user code from accessing the
814 * higher xuseg addresses. Here, we make sure that
815 * everything but the lower xuseg addresses goes down
816 * the module_alloc/vmalloc path.
818 uasm_i_dsrl_safe(p, ptr, tmp, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
819 uasm_il_bnez(p, r, ptr, label_vmalloc);
821 uasm_il_bltz(p, r, tmp, label_vmalloc);
823 /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */
826 /* pgd is in pgd_reg */
828 UASM_i_MFC0(p, ptr, C0_PWBASE);
830 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
832 #if defined(CONFIG_MIPS_PGD_C0_CONTEXT)
834 * &pgd << 11 stored in CONTEXT [23..63].
836 UASM_i_MFC0(p, ptr, C0_CONTEXT);
838 /* Clear lower 23 bits of context. */
839 uasm_i_dins(p, ptr, 0, 0, 23);
841 /* 1 0 1 0 1 << 6 xkphys cached */
842 uasm_i_ori(p, ptr, ptr, 0x540);
843 uasm_i_drotr(p, ptr, ptr, 11);
844 #elif defined(CONFIG_SMP)
845 UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG);
846 uasm_i_dsrl_safe(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
847 UASM_i_LA_mostly(p, tmp, pgdc);
848 uasm_i_daddu(p, ptr, ptr, tmp);
849 uasm_i_dmfc0(p, tmp, C0_BADVADDR);
850 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
852 UASM_i_LA_mostly(p, ptr, pgdc);
853 uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr);
857 uasm_l_vmalloc_done(l, *p);
859 /* get pgd offset in bytes */
860 uasm_i_dsrl_safe(p, tmp, tmp, PGDIR_SHIFT - 3);
862 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3);
863 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */
864 #ifndef __PAGETABLE_PUD_FOLDED
865 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
866 uasm_i_ld(p, ptr, 0, ptr); /* get pud pointer */
867 uasm_i_dsrl_safe(p, tmp, tmp, PUD_SHIFT - 3); /* get pud offset in bytes */
868 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PUD - 1) << 3);
869 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pud offset */
871 #ifndef __PAGETABLE_PMD_FOLDED
872 uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */
873 uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */
874 uasm_i_dsrl_safe(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */
875 uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3);
876 uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */
879 EXPORT_SYMBOL_GPL(build_get_pmde64);
882 * BVADDR is the faulting address, PTR is scratch.
883 * PTR will hold the pgd for vmalloc.
886 build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
887 unsigned int bvaddr, unsigned int ptr,
888 enum vmalloc64_mode mode)
890 long swpd = (long)swapper_pg_dir;
891 int single_insn_swpd;
892 int did_vmalloc_branch = 0;
894 single_insn_swpd = uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd);
896 uasm_l_vmalloc(l, *p);
898 if (mode != not_refill && check_for_high_segbits) {
899 if (single_insn_swpd) {
900 uasm_il_bltz(p, r, bvaddr, label_vmalloc_done);
901 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
902 did_vmalloc_branch = 1;
905 uasm_il_bgez(p, r, bvaddr, label_large_segbits_fault);
908 if (!did_vmalloc_branch) {
909 if (single_insn_swpd) {
910 uasm_il_b(p, r, label_vmalloc_done);
911 uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
913 UASM_i_LA_mostly(p, ptr, swpd);
914 uasm_il_b(p, r, label_vmalloc_done);
915 if (uasm_in_compat_space_p(swpd))
916 uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd));
918 uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
921 if (mode != not_refill && check_for_high_segbits) {
922 uasm_l_large_segbits_fault(l, *p);
924 * We get here if we are an xsseg address, or if we are
925 * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary.
927 * Ignoring xsseg (assume disabled so would generate
928 * (address errors?), the only remaining possibility
929 * is the upper xuseg addresses. On processors with
930 * TLB_SEGBITS <= PGDIR_SHIFT+PGDIR_BITS, these
931 * addresses would have taken an address error. We try
932 * to mimic that here by taking a load/istream page
935 UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
938 if (mode == refill_scratch) {
939 if (scratch_reg >= 0)
940 UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg);
942 UASM_i_LW(p, 1, scratchpad_offset(0), 0);
949 #else /* !CONFIG_64BIT */
952 * TMP and PTR are scratch.
953 * TMP will be clobbered, PTR will hold the pgd entry.
955 void build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr)
958 /* pgd is in pgd_reg */
959 uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg);
960 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
962 long pgdc = (long)pgd_current;
964 /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */
966 uasm_i_mfc0(p, ptr, SMP_CPUID_REG);
967 UASM_i_LA_mostly(p, tmp, pgdc);
968 uasm_i_srl(p, ptr, ptr, SMP_CPUID_PTRSHIFT);
969 uasm_i_addu(p, ptr, tmp, ptr);
971 UASM_i_LA_mostly(p, ptr, pgdc);
973 uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */
974 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
976 uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */
977 uasm_i_sll(p, tmp, tmp, PGD_T_LOG2);
978 uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */
980 EXPORT_SYMBOL_GPL(build_get_pgde32);
982 #endif /* !CONFIG_64BIT */
984 static void build_adjust_context(u32 **p, unsigned int ctx)
986 unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12;
987 unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1);
989 switch (current_cpu_type()) {
1006 UASM_i_SRL(p, ctx, ctx, shift);
1007 uasm_i_andi(p, ctx, ctx, mask);
1010 void build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr)
1013 * Bug workaround for the Nevada. It seems as if under certain
1014 * circumstances the move from cp0_context might produce a
1015 * bogus result when the mfc0 instruction and its consumer are
1016 * in a different cacheline or a load instruction, probably any
1017 * memory reference, is between them.
1019 switch (current_cpu_type()) {
1021 UASM_i_LW(p, ptr, 0, ptr);
1022 GET_CONTEXT(p, tmp); /* get context reg */
1026 GET_CONTEXT(p, tmp); /* get context reg */
1027 UASM_i_LW(p, ptr, 0, ptr);
1031 build_adjust_context(p, tmp);
1032 UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */
1034 EXPORT_SYMBOL_GPL(build_get_ptep);
1036 void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep)
1038 int pte_off_even = 0;
1039 int pte_off_odd = sizeof(pte_t);
1041 #if defined(CONFIG_CPU_MIPS32) && defined(CONFIG_PHYS_ADDR_T_64BIT)
1042 /* The low 32 bits of EntryLo is stored in pte_high */
1043 pte_off_even += offsetof(pte_t, pte_high);
1044 pte_off_odd += offsetof(pte_t, pte_high);
1047 if (IS_ENABLED(CONFIG_XPA)) {
1048 uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */
1049 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
1050 UASM_i_MTC0(p, tmp, C0_ENTRYLO0);
1052 if (cpu_has_xpa && !mips_xpa_disabled) {
1053 uasm_i_lw(p, tmp, 0, ptep);
1054 uasm_i_ext(p, tmp, tmp, 0, 24);
1055 uasm_i_mthc0(p, tmp, C0_ENTRYLO0);
1058 uasm_i_lw(p, tmp, pte_off_odd, ptep); /* odd pte */
1059 UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL));
1060 UASM_i_MTC0(p, tmp, C0_ENTRYLO1);
1062 if (cpu_has_xpa && !mips_xpa_disabled) {
1063 uasm_i_lw(p, tmp, sizeof(pte_t), ptep);
1064 uasm_i_ext(p, tmp, tmp, 0, 24);
1065 uasm_i_mthc0(p, tmp, C0_ENTRYLO1);
1070 UASM_i_LW(p, tmp, pte_off_even, ptep); /* get even pte */
1071 UASM_i_LW(p, ptep, pte_off_odd, ptep); /* get odd pte */
1072 if (r45k_bvahwbug())
1073 build_tlb_probe_entry(p);
1074 build_convert_pte_to_entrylo(p, tmp);
1075 if (r4k_250MHZhwbug())
1076 UASM_i_MTC0(p, 0, C0_ENTRYLO0);
1077 UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */
1078 build_convert_pte_to_entrylo(p, ptep);
1079 if (r45k_bvahwbug())
1080 uasm_i_mfc0(p, tmp, C0_INDEX);
1081 if (r4k_250MHZhwbug())
1082 UASM_i_MTC0(p, 0, C0_ENTRYLO1);
1083 UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */
1085 EXPORT_SYMBOL_GPL(build_update_entries);
1087 struct mips_huge_tlb_info {
1089 int restore_scratch;
1090 bool need_reload_pte;
1093 static struct mips_huge_tlb_info
1094 build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
1095 struct uasm_reloc **r, unsigned int tmp,
1096 unsigned int ptr, int c0_scratch_reg)
1098 struct mips_huge_tlb_info rv;
1099 unsigned int even, odd;
1100 int vmalloc_branch_delay_filled = 0;
1101 const int scratch = 1; /* Our extra working register */
1103 rv.huge_pte = scratch;
1104 rv.restore_scratch = 0;
1105 rv.need_reload_pte = false;
1107 if (check_for_high_segbits) {
1108 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1111 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
1113 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1115 if (c0_scratch_reg >= 0)
1116 UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1118 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1120 uasm_i_dsrl_safe(p, scratch, tmp,
1121 PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
1122 uasm_il_bnez(p, r, scratch, label_vmalloc);
1124 if (pgd_reg == -1) {
1125 vmalloc_branch_delay_filled = 1;
1126 /* Clear lower 23 bits of context. */
1127 uasm_i_dins(p, ptr, 0, 0, 23);
1131 UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg);
1133 UASM_i_MFC0(p, ptr, C0_CONTEXT);
1135 UASM_i_MFC0(p, tmp, C0_BADVADDR);
1137 if (c0_scratch_reg >= 0)
1138 UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1140 UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
1143 /* Clear lower 23 bits of context. */
1144 uasm_i_dins(p, ptr, 0, 0, 23);
1146 uasm_il_bltz(p, r, tmp, label_vmalloc);
1149 if (pgd_reg == -1) {
1150 vmalloc_branch_delay_filled = 1;
1151 /* 1 0 1 0 1 << 6 xkphys cached */
1152 uasm_i_ori(p, ptr, ptr, 0x540);
1153 uasm_i_drotr(p, ptr, ptr, 11);
1156 #ifdef __PAGETABLE_PMD_FOLDED
1157 #define LOC_PTEP scratch
1159 #define LOC_PTEP ptr
1162 if (!vmalloc_branch_delay_filled)
1163 /* get pgd offset in bytes */
1164 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1166 uasm_l_vmalloc_done(l, *p);
1170 * fall-through case = badvaddr *pgd_current
1171 * vmalloc case = badvaddr swapper_pg_dir
1174 if (vmalloc_branch_delay_filled)
1175 /* get pgd offset in bytes */
1176 uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
1178 #ifdef __PAGETABLE_PMD_FOLDED
1179 GET_CONTEXT(p, tmp); /* get context reg */
1181 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3);
1183 if (use_lwx_insns()) {
1184 UASM_i_LWX(p, LOC_PTEP, scratch, ptr);
1186 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */
1187 uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */
1190 #ifndef __PAGETABLE_PUD_FOLDED
1191 /* get pud offset in bytes */
1192 uasm_i_dsrl_safe(p, scratch, tmp, PUD_SHIFT - 3);
1193 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PUD - 1) << 3);
1195 if (use_lwx_insns()) {
1196 UASM_i_LWX(p, ptr, scratch, ptr);
1198 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1199 UASM_i_LW(p, ptr, 0, ptr);
1201 /* ptr contains a pointer to PMD entry */
1202 /* tmp contains the address */
1205 #ifndef __PAGETABLE_PMD_FOLDED
1206 /* get pmd offset in bytes */
1207 uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3);
1208 uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3);
1209 GET_CONTEXT(p, tmp); /* get context reg */
1211 if (use_lwx_insns()) {
1212 UASM_i_LWX(p, scratch, scratch, ptr);
1214 uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
1215 UASM_i_LW(p, scratch, 0, ptr);
1218 /* Adjust the context during the load latency. */
1219 build_adjust_context(p, tmp);
1221 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1222 uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update);
1224 * The in the LWX case we don't want to do the load in the
1225 * delay slot. It cannot issue in the same cycle and may be
1226 * speculative and unneeded.
1228 if (use_lwx_insns())
1230 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
1233 /* build_update_entries */
1234 if (use_lwx_insns()) {
1237 UASM_i_LWX(p, even, scratch, tmp);
1238 UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t));
1239 UASM_i_LWX(p, odd, scratch, tmp);
1241 UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */
1244 UASM_i_LW(p, even, 0, ptr); /* get even pte */
1245 UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */
1248 uasm_i_drotr(p, even, even, ilog2(_PAGE_GLOBAL));
1249 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1250 uasm_i_drotr(p, odd, odd, ilog2(_PAGE_GLOBAL));
1252 uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL));
1253 UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
1254 uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL));
1256 UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
1258 if (c0_scratch_reg >= 0) {
1259 UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg);
1260 build_tlb_write_entry(p, l, r, tlb_random);
1261 uasm_l_leave(l, *p);
1262 rv.restore_scratch = 1;
1263 } else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) {
1264 build_tlb_write_entry(p, l, r, tlb_random);
1265 uasm_l_leave(l, *p);
1266 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1268 UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
1269 build_tlb_write_entry(p, l, r, tlb_random);
1270 uasm_l_leave(l, *p);
1271 rv.restore_scratch = 1;
1274 uasm_i_eret(p); /* return from trap */
1280 * For a 64-bit kernel, we are using the 64-bit XTLB refill exception
1281 * because EXL == 0. If we wrap, we can also use the 32 instruction
1282 * slots before the XTLB refill exception handler which belong to the
1283 * unused TLB refill exception.
1285 #define MIPS64_REFILL_INSNS 32
1287 static void build_r4000_tlb_refill_handler(void)
1289 u32 *p = tlb_handler;
1290 struct uasm_label *l = labels;
1291 struct uasm_reloc *r = relocs;
1293 unsigned int final_len;
1294 struct mips_huge_tlb_info htlb_info __maybe_unused;
1295 enum vmalloc64_mode vmalloc_mode __maybe_unused;
1297 memset(tlb_handler, 0, sizeof(tlb_handler));
1298 memset(labels, 0, sizeof(labels));
1299 memset(relocs, 0, sizeof(relocs));
1300 memset(final_handler, 0, sizeof(final_handler));
1302 if (IS_ENABLED(CONFIG_64BIT) && (scratch_reg >= 0 || scratchpad_available()) && use_bbit_insns()) {
1303 htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1,
1305 vmalloc_mode = refill_scratch;
1307 htlb_info.huge_pte = K0;
1308 htlb_info.restore_scratch = 0;
1309 htlb_info.need_reload_pte = true;
1310 vmalloc_mode = refill_noscratch;
1312 * create the plain linear handler
1314 if (bcm1250_m3_war()) {
1315 unsigned int segbits = 44;
1317 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1318 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
1319 uasm_i_xor(&p, K0, K0, K1);
1320 uasm_i_dsrl_safe(&p, K1, K0, 62);
1321 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
1322 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
1323 uasm_i_or(&p, K0, K0, K1);
1324 uasm_il_bnez(&p, &r, K0, label_leave);
1325 /* No need for uasm_i_nop */
1329 build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
1331 build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
1334 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1335 build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
1338 build_get_ptep(&p, K0, K1);
1339 build_update_entries(&p, K0, K1);
1340 build_tlb_write_entry(&p, &l, &r, tlb_random);
1341 uasm_l_leave(&l, p);
1342 uasm_i_eret(&p); /* return from trap */
1344 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1345 uasm_l_tlb_huge_update(&l, p);
1346 if (htlb_info.need_reload_pte)
1347 UASM_i_LW(&p, htlb_info.huge_pte, 0, K1);
1348 build_huge_update_entries(&p, htlb_info.huge_pte, K1);
1349 build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
1350 htlb_info.restore_scratch);
1354 build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode);
1358 * Overflow check: For the 64bit handler, we need at least one
1359 * free instruction slot for the wrap-around branch. In worst
1360 * case, if the intended insertion point is a delay slot, we
1361 * need three, with the second nop'ed and the third being
1364 switch (boot_cpu_type()) {
1366 if (sizeof(long) == 4) {
1368 /* Loongson2 ebase is different than r4k, we have more space */
1369 if ((p - tlb_handler) > 64)
1370 panic("TLB refill handler space exceeded");
1372 * Now fold the handler in the TLB refill handler space.
1375 /* Simplest case, just copy the handler. */
1376 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1377 final_len = p - tlb_handler;
1380 if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1)
1381 || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3)
1382 && uasm_insn_has_bdelay(relocs,
1383 tlb_handler + MIPS64_REFILL_INSNS - 3)))
1384 panic("TLB refill handler space exceeded");
1386 * Now fold the handler in the TLB refill handler space.
1388 f = final_handler + MIPS64_REFILL_INSNS;
1389 if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) {
1390 /* Just copy the handler. */
1391 uasm_copy_handler(relocs, labels, tlb_handler, p, f);
1392 final_len = p - tlb_handler;
1394 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1395 const enum label_id ls = label_tlb_huge_update;
1397 const enum label_id ls = label_vmalloc;
1403 for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++)
1405 BUG_ON(i == ARRAY_SIZE(labels));
1406 split = labels[i].addr;
1409 * See if we have overflown one way or the other.
1411 if (split > tlb_handler + MIPS64_REFILL_INSNS ||
1412 split < p - MIPS64_REFILL_INSNS)
1417 * Split two instructions before the end. One
1418 * for the branch and one for the instruction
1419 * in the delay slot.
1421 split = tlb_handler + MIPS64_REFILL_INSNS - 2;
1424 * If the branch would fall in a delay slot,
1425 * we must back up an additional instruction
1426 * so that it is no longer in a delay slot.
1428 if (uasm_insn_has_bdelay(relocs, split - 1))
1431 /* Copy first part of the handler. */
1432 uasm_copy_handler(relocs, labels, tlb_handler, split, f);
1433 f += split - tlb_handler;
1436 /* Insert branch. */
1437 uasm_l_split(&l, final_handler);
1438 uasm_il_b(&f, &r, label_split);
1439 if (uasm_insn_has_bdelay(relocs, split))
1442 uasm_copy_handler(relocs, labels,
1443 split, split + 1, f);
1444 uasm_move_labels(labels, f, f + 1, -1);
1450 /* Copy the rest of the handler. */
1451 uasm_copy_handler(relocs, labels, split, p, final_handler);
1452 final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) +
1459 uasm_resolve_relocs(relocs, labels);
1460 pr_debug("Wrote TLB refill handler (%u instructions).\n",
1463 memcpy((void *)ebase, final_handler, 0x100);
1464 local_flush_icache_range(ebase, ebase + 0x100);
1465 dump_handler("r4000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x100));
1468 static void setup_pw(void)
1470 unsigned long pgd_i, pgd_w;
1471 #ifndef __PAGETABLE_PMD_FOLDED
1472 unsigned long pmd_i, pmd_w;
1474 unsigned long pt_i, pt_w;
1475 unsigned long pte_i, pte_w;
1476 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1479 psn = ilog2(_PAGE_HUGE); /* bit used to indicate huge page */
1481 pgd_i = PGDIR_SHIFT; /* 1st level PGD */
1482 #ifndef __PAGETABLE_PMD_FOLDED
1483 pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_ORDER;
1485 pmd_i = PMD_SHIFT; /* 2nd level PMD */
1486 pmd_w = PMD_SHIFT - PAGE_SHIFT;
1488 pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_ORDER;
1491 pt_i = PAGE_SHIFT; /* 3rd level PTE */
1492 pt_w = PAGE_SHIFT - 3;
1494 pte_i = ilog2(_PAGE_GLOBAL);
1497 #ifndef __PAGETABLE_PMD_FOLDED
1498 write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i);
1499 write_c0_pwsize(1 << 30 | pgd_w << 24 | pmd_w << 12 | pt_w << 6 | pte_w);
1501 write_c0_pwfield(pgd_i << 24 | pt_i << 6 | pte_i);
1502 write_c0_pwsize(1 << 30 | pgd_w << 24 | pt_w << 6 | pte_w);
1505 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
1506 write_c0_pwctl(1 << 6 | psn);
1508 write_c0_kpgd((long)swapper_pg_dir);
1509 kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */
1512 static void build_loongson3_tlb_refill_handler(void)
1514 u32 *p = tlb_handler;
1515 struct uasm_label *l = labels;
1516 struct uasm_reloc *r = relocs;
1518 memset(labels, 0, sizeof(labels));
1519 memset(relocs, 0, sizeof(relocs));
1520 memset(tlb_handler, 0, sizeof(tlb_handler));
1522 if (check_for_high_segbits) {
1523 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
1524 uasm_i_dsrl_safe(&p, K1, K0, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
1525 uasm_il_beqz(&p, &r, K1, label_vmalloc);
1528 uasm_il_bgez(&p, &r, K0, label_large_segbits_fault);
1530 uasm_l_vmalloc(&l, p);
1533 uasm_i_dmfc0(&p, K1, C0_PGD);
1535 uasm_i_lddir(&p, K0, K1, 3); /* global page dir */
1536 #ifndef __PAGETABLE_PMD_FOLDED
1537 uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */
1539 uasm_i_ldpte(&p, K1, 0); /* even */
1540 uasm_i_ldpte(&p, K1, 1); /* odd */
1543 /* restore page mask */
1544 if (PM_DEFAULT_MASK >> 16) {
1545 uasm_i_lui(&p, K0, PM_DEFAULT_MASK >> 16);
1546 uasm_i_ori(&p, K0, K0, PM_DEFAULT_MASK & 0xffff);
1547 uasm_i_mtc0(&p, K0, C0_PAGEMASK);
1548 } else if (PM_DEFAULT_MASK) {
1549 uasm_i_ori(&p, K0, 0, PM_DEFAULT_MASK);
1550 uasm_i_mtc0(&p, K0, C0_PAGEMASK);
1552 uasm_i_mtc0(&p, 0, C0_PAGEMASK);
1557 if (check_for_high_segbits) {
1558 uasm_l_large_segbits_fault(&l, p);
1559 UASM_i_LA(&p, K1, (unsigned long)tlb_do_page_fault_0);
1564 uasm_resolve_relocs(relocs, labels);
1565 memcpy((void *)(ebase + 0x80), tlb_handler, 0x80);
1566 local_flush_icache_range(ebase + 0x80, ebase + 0x100);
1567 dump_handler("loongson3_tlb_refill",
1568 (u32 *)(ebase + 0x80), (u32 *)(ebase + 0x100));
1571 static void build_setup_pgd(void)
1574 const int __maybe_unused a1 = 5;
1575 const int __maybe_unused a2 = 6;
1576 u32 *p = (u32 *)msk_isa16_mode((ulong)tlbmiss_handler_setup_pgd);
1577 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1578 long pgdc = (long)pgd_current;
1581 memset(p, 0, tlbmiss_handler_setup_pgd_end - (char *)p);
1582 memset(labels, 0, sizeof(labels));
1583 memset(relocs, 0, sizeof(relocs));
1584 pgd_reg = allocate_kscratch();
1585 #ifdef CONFIG_MIPS_PGD_C0_CONTEXT
1586 if (pgd_reg == -1) {
1587 struct uasm_label *l = labels;
1588 struct uasm_reloc *r = relocs;
1590 /* PGD << 11 in c0_Context */
1592 * If it is a ckseg0 address, convert to a physical
1593 * address. Shifting right by 29 and adding 4 will
1594 * result in zero for these addresses.
1597 UASM_i_SRA(&p, a1, a0, 29);
1598 UASM_i_ADDIU(&p, a1, a1, 4);
1599 uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1);
1601 uasm_i_dinsm(&p, a0, 0, 29, 64 - 29);
1602 uasm_l_tlbl_goaround1(&l, p);
1603 UASM_i_SLL(&p, a0, a0, 11);
1605 UASM_i_MTC0(&p, a0, C0_CONTEXT);
1607 /* PGD in c0_KScratch */
1610 UASM_i_MTC0(&p, a0, C0_PWBASE);
1612 UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
1616 /* Save PGD to pgd_current[smp_processor_id()] */
1617 UASM_i_CPUID_MFC0(&p, a1, SMP_CPUID_REG);
1618 UASM_i_SRL_SAFE(&p, a1, a1, SMP_CPUID_PTRSHIFT);
1619 UASM_i_LA_mostly(&p, a2, pgdc);
1620 UASM_i_ADDU(&p, a2, a2, a1);
1621 UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
1623 UASM_i_LA_mostly(&p, a2, pgdc);
1624 UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2);
1628 /* if pgd_reg is allocated, save PGD also to scratch register */
1630 UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg);
1634 if (p >= (u32 *)tlbmiss_handler_setup_pgd_end)
1635 panic("tlbmiss_handler_setup_pgd space exceeded");
1637 uasm_resolve_relocs(relocs, labels);
1638 pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n",
1639 (unsigned int)(p - (u32 *)tlbmiss_handler_setup_pgd));
1641 dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd,
1642 tlbmiss_handler_setup_pgd_end);
1646 iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr)
1649 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1651 uasm_i_lld(p, pte, 0, ptr);
1654 UASM_i_LL(p, pte, 0, ptr);
1656 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1658 uasm_i_ld(p, pte, 0, ptr);
1661 UASM_i_LW(p, pte, 0, ptr);
1666 iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr,
1667 unsigned int mode, unsigned int scratch)
1669 unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY);
1670 unsigned int swmode = mode & ~hwmode;
1672 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_64bits) {
1673 uasm_i_lui(p, scratch, swmode >> 16);
1674 uasm_i_or(p, pte, pte, scratch);
1675 BUG_ON(swmode & 0xffff);
1677 uasm_i_ori(p, pte, pte, mode);
1681 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1683 uasm_i_scd(p, pte, 0, ptr);
1686 UASM_i_SC(p, pte, 0, ptr);
1688 if (r10000_llsc_war())
1689 uasm_il_beqzl(p, r, pte, label_smp_pgtable_change);
1691 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1693 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1694 if (!cpu_has_64bits) {
1695 /* no uasm_i_nop needed */
1696 uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr);
1697 uasm_i_ori(p, pte, pte, hwmode);
1698 BUG_ON(hwmode & ~0xffff);
1699 uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr);
1700 uasm_il_beqz(p, r, pte, label_smp_pgtable_change);
1701 /* no uasm_i_nop needed */
1702 uasm_i_lw(p, pte, 0, ptr);
1709 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1711 uasm_i_sd(p, pte, 0, ptr);
1714 UASM_i_SW(p, pte, 0, ptr);
1716 # ifdef CONFIG_PHYS_ADDR_T_64BIT
1717 if (!cpu_has_64bits) {
1718 uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr);
1719 uasm_i_ori(p, pte, pte, hwmode);
1720 BUG_ON(hwmode & ~0xffff);
1721 uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr);
1722 uasm_i_lw(p, pte, 0, ptr);
1729 * Check if PTE is present, if not then jump to LABEL. PTR points to
1730 * the page table where this PTE is located, PTE will be re-loaded
1731 * with it's original value.
1734 build_pte_present(u32 **p, struct uasm_reloc **r,
1735 int pte, int ptr, int scratch, enum label_id lid)
1737 int t = scratch >= 0 ? scratch : pte;
1741 if (use_bbit_insns()) {
1742 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid);
1745 if (_PAGE_PRESENT_SHIFT) {
1746 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1749 uasm_i_andi(p, t, cur, 1);
1750 uasm_il_beqz(p, r, t, lid);
1752 /* You lose the SMP race :-(*/
1753 iPTE_LW(p, pte, ptr);
1756 if (_PAGE_PRESENT_SHIFT) {
1757 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1760 uasm_i_andi(p, t, cur,
1761 (_PAGE_PRESENT | _PAGE_NO_READ) >> _PAGE_PRESENT_SHIFT);
1762 uasm_i_xori(p, t, t, _PAGE_PRESENT >> _PAGE_PRESENT_SHIFT);
1763 uasm_il_bnez(p, r, t, lid);
1765 /* You lose the SMP race :-(*/
1766 iPTE_LW(p, pte, ptr);
1770 /* Make PTE valid, store result in PTR. */
1772 build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte,
1773 unsigned int ptr, unsigned int scratch)
1775 unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED;
1777 iPTE_SW(p, r, pte, ptr, mode, scratch);
1781 * Check if PTE can be written to, if not branch to LABEL. Regardless
1782 * restore PTE with value from PTR when done.
1785 build_pte_writable(u32 **p, struct uasm_reloc **r,
1786 unsigned int pte, unsigned int ptr, int scratch,
1789 int t = scratch >= 0 ? scratch : pte;
1792 if (_PAGE_PRESENT_SHIFT) {
1793 uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT);
1796 uasm_i_andi(p, t, cur,
1797 (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
1798 uasm_i_xori(p, t, t,
1799 (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT);
1800 uasm_il_bnez(p, r, t, lid);
1802 /* You lose the SMP race :-(*/
1803 iPTE_LW(p, pte, ptr);
1808 /* Make PTE writable, update software status bits as well, then store
1812 build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte,
1813 unsigned int ptr, unsigned int scratch)
1815 unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID
1818 iPTE_SW(p, r, pte, ptr, mode, scratch);
1822 * Check if PTE can be modified, if not branch to LABEL. Regardless
1823 * restore PTE with value from PTR when done.
1826 build_pte_modifiable(u32 **p, struct uasm_reloc **r,
1827 unsigned int pte, unsigned int ptr, int scratch,
1830 if (use_bbit_insns()) {
1831 uasm_il_bbit0(p, r, pte, ilog2(_PAGE_WRITE), lid);
1834 int t = scratch >= 0 ? scratch : pte;
1835 uasm_i_srl(p, t, pte, _PAGE_WRITE_SHIFT);
1836 uasm_i_andi(p, t, t, 1);
1837 uasm_il_beqz(p, r, t, lid);
1839 /* You lose the SMP race :-(*/
1840 iPTE_LW(p, pte, ptr);
1844 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
1848 * R3000 style TLB load/store/modify handlers.
1852 * This places the pte into ENTRYLO0 and writes it with tlbwi.
1856 build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp)
1858 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1859 uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */
1862 uasm_i_rfe(p); /* branch delay */
1866 * This places the pte into ENTRYLO0 and writes it with tlbwi
1867 * or tlbwr as appropriate. This is because the index register
1868 * may have the probe fail bit set as a result of a trap on a
1869 * kseg2 access, i.e. without refill. Then it returns.
1872 build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l,
1873 struct uasm_reloc **r, unsigned int pte,
1876 uasm_i_mfc0(p, tmp, C0_INDEX);
1877 uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */
1878 uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */
1879 uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */
1880 uasm_i_tlbwi(p); /* cp0 delay */
1882 uasm_i_rfe(p); /* branch delay */
1883 uasm_l_r3000_write_probe_fail(l, *p);
1884 uasm_i_tlbwr(p); /* cp0 delay */
1886 uasm_i_rfe(p); /* branch delay */
1890 build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte,
1893 long pgdc = (long)pgd_current;
1895 uasm_i_mfc0(p, pte, C0_BADVADDR);
1896 uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */
1897 uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr);
1898 uasm_i_srl(p, pte, pte, 22); /* load delay */
1899 uasm_i_sll(p, pte, pte, 2);
1900 uasm_i_addu(p, ptr, ptr, pte);
1901 uasm_i_mfc0(p, pte, C0_CONTEXT);
1902 uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */
1903 uasm_i_andi(p, pte, pte, 0xffc); /* load delay */
1904 uasm_i_addu(p, ptr, ptr, pte);
1905 uasm_i_lw(p, pte, 0, ptr);
1906 uasm_i_tlbp(p); /* load delay */
1909 static void build_r3000_tlb_load_handler(void)
1911 u32 *p = (u32 *)handle_tlbl;
1912 struct uasm_label *l = labels;
1913 struct uasm_reloc *r = relocs;
1915 memset(p, 0, handle_tlbl_end - (char *)p);
1916 memset(labels, 0, sizeof(labels));
1917 memset(relocs, 0, sizeof(relocs));
1919 build_r3000_tlbchange_handler_head(&p, K0, K1);
1920 build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl);
1921 uasm_i_nop(&p); /* load delay */
1922 build_make_valid(&p, &r, K0, K1, -1);
1923 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1925 uasm_l_nopage_tlbl(&l, p);
1926 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
1929 if (p >= (u32 *)handle_tlbl_end)
1930 panic("TLB load handler fastpath space exceeded");
1932 uasm_resolve_relocs(relocs, labels);
1933 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
1934 (unsigned int)(p - (u32 *)handle_tlbl));
1936 dump_handler("r3000_tlb_load", handle_tlbl, handle_tlbl_end);
1939 static void build_r3000_tlb_store_handler(void)
1941 u32 *p = (u32 *)handle_tlbs;
1942 struct uasm_label *l = labels;
1943 struct uasm_reloc *r = relocs;
1945 memset(p, 0, handle_tlbs_end - (char *)p);
1946 memset(labels, 0, sizeof(labels));
1947 memset(relocs, 0, sizeof(relocs));
1949 build_r3000_tlbchange_handler_head(&p, K0, K1);
1950 build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs);
1951 uasm_i_nop(&p); /* load delay */
1952 build_make_write(&p, &r, K0, K1, -1);
1953 build_r3000_tlb_reload_write(&p, &l, &r, K0, K1);
1955 uasm_l_nopage_tlbs(&l, p);
1956 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1959 if (p >= (u32 *)handle_tlbs_end)
1960 panic("TLB store handler fastpath space exceeded");
1962 uasm_resolve_relocs(relocs, labels);
1963 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
1964 (unsigned int)(p - (u32 *)handle_tlbs));
1966 dump_handler("r3000_tlb_store", handle_tlbs, handle_tlbs_end);
1969 static void build_r3000_tlb_modify_handler(void)
1971 u32 *p = (u32 *)handle_tlbm;
1972 struct uasm_label *l = labels;
1973 struct uasm_reloc *r = relocs;
1975 memset(p, 0, handle_tlbm_end - (char *)p);
1976 memset(labels, 0, sizeof(labels));
1977 memset(relocs, 0, sizeof(relocs));
1979 build_r3000_tlbchange_handler_head(&p, K0, K1);
1980 build_pte_modifiable(&p, &r, K0, K1, -1, label_nopage_tlbm);
1981 uasm_i_nop(&p); /* load delay */
1982 build_make_write(&p, &r, K0, K1, -1);
1983 build_r3000_pte_reload_tlbwi(&p, K0, K1);
1985 uasm_l_nopage_tlbm(&l, p);
1986 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
1989 if (p >= (u32 *)handle_tlbm_end)
1990 panic("TLB modify handler fastpath space exceeded");
1992 uasm_resolve_relocs(relocs, labels);
1993 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
1994 (unsigned int)(p - (u32 *)handle_tlbm));
1996 dump_handler("r3000_tlb_modify", handle_tlbm, handle_tlbm_end);
1998 #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */
2000 static bool cpu_has_tlbex_tlbp_race(void)
2003 * When a Hardware Table Walker is running it can replace TLB entries
2004 * at any time, leading to a race between it & the CPU.
2010 * If the CPU shares FTLB RAM with its siblings then our entry may be
2011 * replaced at any time by a sibling performing a write to the FTLB.
2013 if (cpu_has_shared_ftlb_ram)
2016 /* In all other cases there ought to be no race condition to handle */
2021 * R4000 style TLB load/store/modify handlers.
2023 static struct work_registers
2024 build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l,
2025 struct uasm_reloc **r)
2027 struct work_registers wr = build_get_work_registers(p);
2030 build_get_pmde64(p, l, r, wr.r1, wr.r2); /* get pmd in ptr */
2032 build_get_pgde32(p, wr.r1, wr.r2); /* get pgd in ptr */
2035 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2037 * For huge tlb entries, pmd doesn't contain an address but
2038 * instead contains the tlb pte. Check the PAGE_HUGE bit and
2039 * see if we need to jump to huge tlb processing.
2041 build_is_huge_pte(p, r, wr.r1, wr.r2, label_tlb_huge_update);
2044 UASM_i_MFC0(p, wr.r1, C0_BADVADDR);
2045 UASM_i_LW(p, wr.r2, 0, wr.r2);
2046 UASM_i_SRL(p, wr.r1, wr.r1, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2);
2047 uasm_i_andi(p, wr.r1, wr.r1, (PTRS_PER_PTE - 1) << PTE_T_LOG2);
2048 UASM_i_ADDU(p, wr.r2, wr.r2, wr.r1);
2051 uasm_l_smp_pgtable_change(l, *p);
2053 iPTE_LW(p, wr.r1, wr.r2); /* get even pte */
2054 if (!m4kc_tlbp_war()) {
2055 build_tlb_probe_entry(p);
2056 if (cpu_has_tlbex_tlbp_race()) {
2057 /* race condition happens, leaving */
2059 uasm_i_mfc0(p, wr.r3, C0_INDEX);
2060 uasm_il_bltz(p, r, wr.r3, label_leave);
2068 build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l,
2069 struct uasm_reloc **r, unsigned int tmp,
2072 uasm_i_ori(p, ptr, ptr, sizeof(pte_t));
2073 uasm_i_xori(p, ptr, ptr, sizeof(pte_t));
2074 build_update_entries(p, tmp, ptr);
2075 build_tlb_write_entry(p, l, r, tlb_indexed);
2076 uasm_l_leave(l, *p);
2077 build_restore_work_registers(p);
2078 uasm_i_eret(p); /* return from trap */
2081 build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill);
2085 static void build_r4000_tlb_load_handler(void)
2087 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl);
2088 struct uasm_label *l = labels;
2089 struct uasm_reloc *r = relocs;
2090 struct work_registers wr;
2092 memset(p, 0, handle_tlbl_end - (char *)p);
2093 memset(labels, 0, sizeof(labels));
2094 memset(relocs, 0, sizeof(relocs));
2096 if (bcm1250_m3_war()) {
2097 unsigned int segbits = 44;
2099 uasm_i_dmfc0(&p, K0, C0_BADVADDR);
2100 uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
2101 uasm_i_xor(&p, K0, K0, K1);
2102 uasm_i_dsrl_safe(&p, K1, K0, 62);
2103 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
2104 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
2105 uasm_i_or(&p, K0, K0, K1);
2106 uasm_il_bnez(&p, &r, K0, label_leave);
2107 /* No need for uasm_i_nop */
2110 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2111 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
2112 if (m4kc_tlbp_war())
2113 build_tlb_probe_entry(&p);
2115 if (cpu_has_rixi && !cpu_has_rixiex) {
2117 * If the page is not _PAGE_VALID, RI or XI could not
2118 * have triggered it. Skip the expensive test..
2120 if (use_bbit_insns()) {
2121 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
2122 label_tlbl_goaround1);
2124 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
2125 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1);
2130 * Warn if something may race with us & replace the TLB entry
2131 * before we read it here. Everything with such races should
2132 * also have dedicated RiXi exception handlers, so this
2135 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
2139 switch (current_cpu_type()) {
2141 if (cpu_has_mips_r2_exec_hazard) {
2144 case CPU_CAVIUM_OCTEON:
2145 case CPU_CAVIUM_OCTEON_PLUS:
2146 case CPU_CAVIUM_OCTEON2:
2151 /* Examine entrylo 0 or 1 based on ptr. */
2152 if (use_bbit_insns()) {
2153 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
2155 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
2156 uasm_i_beqz(&p, wr.r3, 8);
2158 /* load it in the delay slot*/
2159 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
2160 /* load it if ptr is odd */
2161 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
2163 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
2164 * XI must have triggered it.
2166 if (use_bbit_insns()) {
2167 uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl);
2169 uasm_l_tlbl_goaround1(&l, p);
2171 uasm_i_andi(&p, wr.r3, wr.r3, 2);
2172 uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl);
2175 uasm_l_tlbl_goaround1(&l, p);
2177 build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3);
2178 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2180 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2182 * This is the entry point when build_r4000_tlbchange_handler_head
2183 * spots a huge page.
2185 uasm_l_tlb_huge_update(&l, p);
2186 iPTE_LW(&p, wr.r1, wr.r2);
2187 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl);
2188 build_tlb_probe_entry(&p);
2190 if (cpu_has_rixi && !cpu_has_rixiex) {
2192 * If the page is not _PAGE_VALID, RI or XI could not
2193 * have triggered it. Skip the expensive test..
2195 if (use_bbit_insns()) {
2196 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID),
2197 label_tlbl_goaround2);
2199 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID);
2200 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
2205 * Warn if something may race with us & replace the TLB entry
2206 * before we read it here. Everything with such races should
2207 * also have dedicated RiXi exception handlers, so this
2210 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path");
2214 switch (current_cpu_type()) {
2216 if (cpu_has_mips_r2_exec_hazard) {
2219 case CPU_CAVIUM_OCTEON:
2220 case CPU_CAVIUM_OCTEON_PLUS:
2221 case CPU_CAVIUM_OCTEON2:
2226 /* Examine entrylo 0 or 1 based on ptr. */
2227 if (use_bbit_insns()) {
2228 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8);
2230 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t));
2231 uasm_i_beqz(&p, wr.r3, 8);
2233 /* load it in the delay slot*/
2234 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0);
2235 /* load it if ptr is odd */
2236 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1);
2238 * If the entryLo (now in wr.r3) is valid (bit 1), RI or
2239 * XI must have triggered it.
2241 if (use_bbit_insns()) {
2242 uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2);
2244 uasm_i_andi(&p, wr.r3, wr.r3, 2);
2245 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
2247 if (PM_DEFAULT_MASK == 0)
2250 * We clobbered C0_PAGEMASK, restore it. On the other branch
2251 * it is restored in build_huge_tlb_write_entry.
2253 build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0);
2255 uasm_l_tlbl_goaround2(&l, p);
2257 uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID));
2258 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
2261 uasm_l_nopage_tlbl(&l, p);
2262 build_restore_work_registers(&p);
2263 #ifdef CONFIG_CPU_MICROMIPS
2264 if ((unsigned long)tlb_do_page_fault_0 & 1) {
2265 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0));
2266 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0));
2270 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
2273 if (p >= (u32 *)handle_tlbl_end)
2274 panic("TLB load handler fastpath space exceeded");
2276 uasm_resolve_relocs(relocs, labels);
2277 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n",
2278 (unsigned int)(p - (u32 *)handle_tlbl));
2280 dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_end);
2283 static void build_r4000_tlb_store_handler(void)
2285 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbs);
2286 struct uasm_label *l = labels;
2287 struct uasm_reloc *r = relocs;
2288 struct work_registers wr;
2290 memset(p, 0, handle_tlbs_end - (char *)p);
2291 memset(labels, 0, sizeof(labels));
2292 memset(relocs, 0, sizeof(relocs));
2294 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2295 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2296 if (m4kc_tlbp_war())
2297 build_tlb_probe_entry(&p);
2298 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);
2299 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2301 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2303 * This is the entry point when
2304 * build_r4000_tlbchange_handler_head spots a huge page.
2306 uasm_l_tlb_huge_update(&l, p);
2307 iPTE_LW(&p, wr.r1, wr.r2);
2308 build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs);
2309 build_tlb_probe_entry(&p);
2310 uasm_i_ori(&p, wr.r1, wr.r1,
2311 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2312 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
2315 uasm_l_nopage_tlbs(&l, p);
2316 build_restore_work_registers(&p);
2317 #ifdef CONFIG_CPU_MICROMIPS
2318 if ((unsigned long)tlb_do_page_fault_1 & 1) {
2319 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
2320 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
2324 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2327 if (p >= (u32 *)handle_tlbs_end)
2328 panic("TLB store handler fastpath space exceeded");
2330 uasm_resolve_relocs(relocs, labels);
2331 pr_debug("Wrote TLB store handler fastpath (%u instructions).\n",
2332 (unsigned int)(p - (u32 *)handle_tlbs));
2334 dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_end);
2337 static void build_r4000_tlb_modify_handler(void)
2339 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbm);
2340 struct uasm_label *l = labels;
2341 struct uasm_reloc *r = relocs;
2342 struct work_registers wr;
2344 memset(p, 0, handle_tlbm_end - (char *)p);
2345 memset(labels, 0, sizeof(labels));
2346 memset(relocs, 0, sizeof(relocs));
2348 wr = build_r4000_tlbchange_handler_head(&p, &l, &r);
2349 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2350 if (m4kc_tlbp_war())
2351 build_tlb_probe_entry(&p);
2352 /* Present and writable bits set, set accessed and dirty bits. */
2353 build_make_write(&p, &r, wr.r1, wr.r2, wr.r3);
2354 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2);
2356 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
2358 * This is the entry point when
2359 * build_r4000_tlbchange_handler_head spots a huge page.
2361 uasm_l_tlb_huge_update(&l, p);
2362 iPTE_LW(&p, wr.r1, wr.r2);
2363 build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm);
2364 build_tlb_probe_entry(&p);
2365 uasm_i_ori(&p, wr.r1, wr.r1,
2366 _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
2367 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0);
2370 uasm_l_nopage_tlbm(&l, p);
2371 build_restore_work_registers(&p);
2372 #ifdef CONFIG_CPU_MICROMIPS
2373 if ((unsigned long)tlb_do_page_fault_1 & 1) {
2374 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
2375 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
2379 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
2382 if (p >= (u32 *)handle_tlbm_end)
2383 panic("TLB modify handler fastpath space exceeded");
2385 uasm_resolve_relocs(relocs, labels);
2386 pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n",
2387 (unsigned int)(p - (u32 *)handle_tlbm));
2389 dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_end);
2392 static void flush_tlb_handlers(void)
2394 local_flush_icache_range((unsigned long)handle_tlbl,
2395 (unsigned long)handle_tlbl_end);
2396 local_flush_icache_range((unsigned long)handle_tlbs,
2397 (unsigned long)handle_tlbs_end);
2398 local_flush_icache_range((unsigned long)handle_tlbm,
2399 (unsigned long)handle_tlbm_end);
2400 local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd,
2401 (unsigned long)tlbmiss_handler_setup_pgd_end);
2404 static void print_htw_config(void)
2406 unsigned long config;
2408 const int field = 2 * sizeof(unsigned long);
2410 config = read_c0_pwfield();
2411 pr_debug("PWField (0x%0*lx): GDI: 0x%02lx UDI: 0x%02lx MDI: 0x%02lx PTI: 0x%02lx PTEI: 0x%02lx\n",
2413 (config & MIPS_PWFIELD_GDI_MASK) >> MIPS_PWFIELD_GDI_SHIFT,
2414 (config & MIPS_PWFIELD_UDI_MASK) >> MIPS_PWFIELD_UDI_SHIFT,
2415 (config & MIPS_PWFIELD_MDI_MASK) >> MIPS_PWFIELD_MDI_SHIFT,
2416 (config & MIPS_PWFIELD_PTI_MASK) >> MIPS_PWFIELD_PTI_SHIFT,
2417 (config & MIPS_PWFIELD_PTEI_MASK) >> MIPS_PWFIELD_PTEI_SHIFT);
2419 config = read_c0_pwsize();
2420 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",
2422 (config & MIPS_PWSIZE_PS_MASK) >> MIPS_PWSIZE_PS_SHIFT,
2423 (config & MIPS_PWSIZE_GDW_MASK) >> MIPS_PWSIZE_GDW_SHIFT,
2424 (config & MIPS_PWSIZE_UDW_MASK) >> MIPS_PWSIZE_UDW_SHIFT,
2425 (config & MIPS_PWSIZE_MDW_MASK) >> MIPS_PWSIZE_MDW_SHIFT,
2426 (config & MIPS_PWSIZE_PTW_MASK) >> MIPS_PWSIZE_PTW_SHIFT,
2427 (config & MIPS_PWSIZE_PTEW_MASK) >> MIPS_PWSIZE_PTEW_SHIFT);
2429 pwctl = read_c0_pwctl();
2430 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",
2432 (pwctl & MIPS_PWCTL_PWEN_MASK) >> MIPS_PWCTL_PWEN_SHIFT,
2433 (pwctl & MIPS_PWCTL_XK_MASK) >> MIPS_PWCTL_XK_SHIFT,
2434 (pwctl & MIPS_PWCTL_XS_MASK) >> MIPS_PWCTL_XS_SHIFT,
2435 (pwctl & MIPS_PWCTL_XU_MASK) >> MIPS_PWCTL_XU_SHIFT,
2436 (pwctl & MIPS_PWCTL_DPH_MASK) >> MIPS_PWCTL_DPH_SHIFT,
2437 (pwctl & MIPS_PWCTL_HUGEPG_MASK) >> MIPS_PWCTL_HUGEPG_SHIFT,
2438 (pwctl & MIPS_PWCTL_PSN_MASK) >> MIPS_PWCTL_PSN_SHIFT);
2441 static void config_htw_params(void)
2443 unsigned long pwfield, pwsize, ptei;
2444 unsigned int config;
2447 * We are using 2-level page tables, so we only need to
2448 * setup GDW and PTW appropriately. UDW and MDW will remain 0.
2449 * The default value of GDI/UDI/MDI/PTI is 0xc. It is illegal to
2450 * write values less than 0xc in these fields because the entire
2451 * write will be dropped. As a result of which, we must preserve
2452 * the original reset values and overwrite only what we really want.
2455 pwfield = read_c0_pwfield();
2456 /* re-initialize the GDI field */
2457 pwfield &= ~MIPS_PWFIELD_GDI_MASK;
2458 pwfield |= PGDIR_SHIFT << MIPS_PWFIELD_GDI_SHIFT;
2459 /* re-initialize the PTI field including the even/odd bit */
2460 pwfield &= ~MIPS_PWFIELD_PTI_MASK;
2461 pwfield |= PAGE_SHIFT << MIPS_PWFIELD_PTI_SHIFT;
2462 if (CONFIG_PGTABLE_LEVELS >= 3) {
2463 pwfield &= ~MIPS_PWFIELD_MDI_MASK;
2464 pwfield |= PMD_SHIFT << MIPS_PWFIELD_MDI_SHIFT;
2466 /* Set the PTEI right shift */
2467 ptei = _PAGE_GLOBAL_SHIFT << MIPS_PWFIELD_PTEI_SHIFT;
2469 write_c0_pwfield(pwfield);
2470 /* Check whether the PTEI value is supported */
2471 back_to_back_c0_hazard();
2472 pwfield = read_c0_pwfield();
2473 if (((pwfield & MIPS_PWFIELD_PTEI_MASK) << MIPS_PWFIELD_PTEI_SHIFT)
2475 pr_warn("Unsupported PTEI field value: 0x%lx. HTW will not be enabled",
2478 * Drop option to avoid HTW being enabled via another path
2481 current_cpu_data.options &= ~MIPS_CPU_HTW;
2485 pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT;
2486 pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT;
2487 if (CONFIG_PGTABLE_LEVELS >= 3)
2488 pwsize |= ilog2(PTRS_PER_PMD) << MIPS_PWSIZE_MDW_SHIFT;
2490 /* Set pointer size to size of directory pointers */
2491 if (IS_ENABLED(CONFIG_64BIT))
2492 pwsize |= MIPS_PWSIZE_PS_MASK;
2493 /* PTEs may be multiple pointers long (e.g. with XPA) */
2494 pwsize |= ((PTE_T_LOG2 - PGD_T_LOG2) << MIPS_PWSIZE_PTEW_SHIFT)
2495 & MIPS_PWSIZE_PTEW_MASK;
2497 write_c0_pwsize(pwsize);
2499 /* Make sure everything is set before we enable the HTW */
2500 back_to_back_c0_hazard();
2503 * Enable HTW (and only for XUSeg on 64-bit), and disable the rest of
2506 config = 1 << MIPS_PWCTL_PWEN_SHIFT;
2507 if (IS_ENABLED(CONFIG_64BIT))
2508 config |= MIPS_PWCTL_XU_MASK;
2509 write_c0_pwctl(config);
2510 pr_info("Hardware Page Table Walker enabled\n");
2515 static void config_xpa_params(void)
2518 unsigned int pagegrain;
2520 if (mips_xpa_disabled) {
2521 pr_info("Extended Physical Addressing (XPA) disabled\n");
2525 pagegrain = read_c0_pagegrain();
2526 write_c0_pagegrain(pagegrain | PG_ELPA);
2527 back_to_back_c0_hazard();
2528 pagegrain = read_c0_pagegrain();
2530 if (pagegrain & PG_ELPA)
2531 pr_info("Extended Physical Addressing (XPA) enabled\n");
2533 panic("Extended Physical Addressing (XPA) disabled");
2537 static void check_pabits(void)
2539 unsigned long entry;
2540 unsigned pabits, fillbits;
2542 if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
2544 * We'll only be making use of the fact that we can rotate bits
2545 * into the fill if the CPU supports RIXI, so don't bother
2546 * probing this for CPUs which don't.
2551 write_c0_entrylo0(~0ul);
2552 back_to_back_c0_hazard();
2553 entry = read_c0_entrylo0();
2555 /* clear all non-PFN bits */
2556 entry &= ~((1 << MIPS_ENTRYLO_PFN_SHIFT) - 1);
2557 entry &= ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI);
2559 /* find a lower bound on PABITS, and upper bound on fill bits */
2560 pabits = fls_long(entry) + 6;
2561 fillbits = max_t(int, (int)BITS_PER_LONG - pabits, 0);
2563 /* minus the RI & XI bits */
2564 fillbits -= min_t(unsigned, fillbits, 2);
2566 if (fillbits >= ilog2(_PAGE_NO_EXEC))
2567 fill_includes_sw_bits = true;
2569 pr_debug("Entry* registers contain %u fill bits\n", fillbits);
2572 void build_tlb_refill_handler(void)
2575 * The refill handler is generated per-CPU, multi-node systems
2576 * may have local storage for it. The other handlers are only
2579 static int run_once = 0;
2581 if (IS_ENABLED(CONFIG_XPA) && !cpu_has_rixi)
2582 panic("Kernels supporting XPA currently require CPUs with RIXI");
2584 output_pgtable_bits_defines();
2588 check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
2591 switch (current_cpu_type()) {
2599 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
2600 if (cpu_has_local_ebase)
2601 build_r3000_tlb_refill_handler();
2603 if (!cpu_has_local_ebase)
2604 build_r3000_tlb_refill_handler();
2606 build_r3000_tlb_load_handler();
2607 build_r3000_tlb_store_handler();
2608 build_r3000_tlb_modify_handler();
2609 flush_tlb_handlers();
2613 panic("No R3000 TLB refill handler");
2618 panic("No R8000 TLB refill handler yet");
2626 scratch_reg = allocate_kscratch();
2628 build_r4000_tlb_load_handler();
2629 build_r4000_tlb_store_handler();
2630 build_r4000_tlb_modify_handler();
2632 build_loongson3_tlb_refill_handler();
2633 else if (!cpu_has_local_ebase)
2634 build_r4000_tlb_refill_handler();
2635 flush_tlb_handlers();
2638 if (cpu_has_local_ebase)
2639 build_r4000_tlb_refill_handler();
2641 config_xpa_params();
2643 config_htw_params();