/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Synthesize TLB refill handlers at runtime. * * Copyright (C) 2004, 2005, 2006, 2008 Thiemo Seufer * Copyright (C) 2005, 2007, 2008, 2009 Maciej W. Rozycki * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 2008, 2009 Cavium Networks, Inc. * Copyright (C) 2011 MIPS Technologies, Inc. * * ... and the days got worse and worse and now you see * I've gone completely out of my mind. * * They're coming to take me a away haha * they're coming to take me a away hoho hihi haha * to the funny farm where code is beautiful all the time ... * * (Condolences to Napoleon XIV) */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int mips_xpa_disabled; static int __init xpa_disable(char *s) { mips_xpa_disabled = 1; return 1; } __setup("noxpa", xpa_disable); /* * TLB load/store/modify handlers. * * Only the fastpath gets synthesized at runtime, the slowpath for * do_page_fault remains normal asm. */ extern void tlb_do_page_fault_0(void); extern void tlb_do_page_fault_1(void); struct work_registers { int r1; int r2; int r3; }; struct tlb_reg_save { unsigned long a; unsigned long b; } ____cacheline_aligned_in_smp; static struct tlb_reg_save handler_reg_save[NR_CPUS]; static inline int r45k_bvahwbug(void) { /* XXX: We should probe for the presence of this bug, but we don't. */ return 0; } static inline int r4k_250MHZhwbug(void) { /* XXX: We should probe for the presence of this bug, but we don't. */ return 0; } extern int sb1250_m3_workaround_needed(void); static inline int __maybe_unused bcm1250_m3_war(void) { if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS)) return sb1250_m3_workaround_needed(); return 0; } static inline int __maybe_unused r10000_llsc_war(void) { return IS_ENABLED(CONFIG_WAR_R10000_LLSC); } static int use_bbit_insns(void) { switch (current_cpu_type()) { case CPU_CAVIUM_OCTEON: case CPU_CAVIUM_OCTEON_PLUS: case CPU_CAVIUM_OCTEON2: case CPU_CAVIUM_OCTEON3: return 1; default: return 0; } } static int use_lwx_insns(void) { switch (current_cpu_type()) { case CPU_CAVIUM_OCTEON2: case CPU_CAVIUM_OCTEON3: return 1; default: return 0; } } #if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \ CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0 static bool scratchpad_available(void) { return true; } static int scratchpad_offset(int i) { /* * CVMSEG starts at address -32768 and extends for * CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines. */ i += 1; /* Kernel use starts at the top and works down. */ return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768; } #else static bool scratchpad_available(void) { return false; } static int scratchpad_offset(int i) { BUG(); /* Really unreachable, but evidently some GCC want this. */ return 0; } #endif /* * Found by experiment: At least some revisions of the 4kc throw under * some circumstances a machine check exception, triggered by invalid * values in the index register. Delaying the tlbp instruction until * after the next branch, plus adding an additional nop in front of * tlbwi/tlbwr avoids the invalid index register values. Nobody knows * why; it's not an issue caused by the core RTL. * */ static int m4kc_tlbp_war(void) { return current_cpu_type() == CPU_4KC; } /* Handle labels (which must be positive integers). */ enum label_id { label_second_part = 1, label_leave, label_vmalloc, label_vmalloc_done, label_tlbw_hazard_0, label_split = label_tlbw_hazard_0 + 8, label_tlbl_goaround1, label_tlbl_goaround2, label_nopage_tlbl, label_nopage_tlbs, label_nopage_tlbm, label_smp_pgtable_change, label_r3000_write_probe_fail, label_large_segbits_fault, #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT label_tlb_huge_update, #endif }; UASM_L_LA(_second_part) UASM_L_LA(_leave) UASM_L_LA(_vmalloc) UASM_L_LA(_vmalloc_done) /* _tlbw_hazard_x is handled differently. */ UASM_L_LA(_split) UASM_L_LA(_tlbl_goaround1) UASM_L_LA(_tlbl_goaround2) UASM_L_LA(_nopage_tlbl) UASM_L_LA(_nopage_tlbs) UASM_L_LA(_nopage_tlbm) UASM_L_LA(_smp_pgtable_change) UASM_L_LA(_r3000_write_probe_fail) UASM_L_LA(_large_segbits_fault) #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT UASM_L_LA(_tlb_huge_update) #endif static int hazard_instance; static void uasm_bgezl_hazard(u32 **p, struct uasm_reloc **r, int instance) { switch (instance) { case 0 ... 7: uasm_il_bgezl(p, r, 0, label_tlbw_hazard_0 + instance); return; default: BUG(); } } static void uasm_bgezl_label(struct uasm_label **l, u32 **p, int instance) { switch (instance) { case 0 ... 7: uasm_build_label(l, *p, label_tlbw_hazard_0 + instance); break; default: BUG(); } } /* * pgtable bits are assigned dynamically depending on processor feature * and statically based on kernel configuration. This spits out the actual * values the kernel is using. Required to make sense from disassembled * TLB exception handlers. */ static void output_pgtable_bits_defines(void) { #define pr_define(fmt, ...) \ pr_debug("#define " fmt, ##__VA_ARGS__) pr_debug("#include \n"); pr_debug("#include \n"); pr_debug("\n"); pr_define("_PAGE_PRESENT_SHIFT %d\n", _PAGE_PRESENT_SHIFT); pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT); pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT); pr_define("_PAGE_ACCESSED_SHIFT %d\n", _PAGE_ACCESSED_SHIFT); pr_define("_PAGE_MODIFIED_SHIFT %d\n", _PAGE_MODIFIED_SHIFT); #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT pr_define("_PAGE_HUGE_SHIFT %d\n", _PAGE_HUGE_SHIFT); #endif #ifdef _PAGE_NO_EXEC_SHIFT if (cpu_has_rixi) pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT); #endif pr_define("_PAGE_GLOBAL_SHIFT %d\n", _PAGE_GLOBAL_SHIFT); pr_define("_PAGE_VALID_SHIFT %d\n", _PAGE_VALID_SHIFT); pr_define("_PAGE_DIRTY_SHIFT %d\n", _PAGE_DIRTY_SHIFT); pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT); pr_debug("\n"); } static inline void dump_handler(const char *symbol, const void *start, const void *end) { unsigned int count = (end - start) / sizeof(u32); const u32 *handler = start; int i; pr_debug("LEAF(%s)\n", symbol); pr_debug("\t.set push\n"); pr_debug("\t.set noreorder\n"); for (i = 0; i < count; i++) pr_debug("\t.word\t0x%08x\t\t# %p\n", handler[i], &handler[i]); pr_debug("\t.set\tpop\n"); pr_debug("\tEND(%s)\n", symbol); } /* The only general purpose registers allowed in TLB handlers. */ #define K0 26 #define K1 27 /* Some CP0 registers */ #define C0_INDEX 0, 0 #define C0_ENTRYLO0 2, 0 #define C0_TCBIND 2, 2 #define C0_ENTRYLO1 3, 0 #define C0_CONTEXT 4, 0 #define C0_PAGEMASK 5, 0 #define C0_PWBASE 5, 5 #define C0_PWFIELD 5, 6 #define C0_PWSIZE 5, 7 #define C0_PWCTL 6, 6 #define C0_BADVADDR 8, 0 #define C0_PGD 9, 7 #define C0_ENTRYHI 10, 0 #define C0_EPC 14, 0 #define C0_XCONTEXT 20, 0 #ifdef CONFIG_64BIT # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_XCONTEXT) #else # define GET_CONTEXT(buf, reg) UASM_i_MFC0(buf, reg, C0_CONTEXT) #endif /* The worst case length of the handler is around 18 instructions for * R3000-style TLBs and up to 63 instructions for R4000-style TLBs. * Maximum space available is 32 instructions for R3000 and 64 * instructions for R4000. * * We deliberately chose a buffer size of 128, so we won't scribble * over anything important on overflow before we panic. */ static u32 tlb_handler[128]; /* simply assume worst case size for labels and relocs */ static struct uasm_label labels[128]; static struct uasm_reloc relocs[128]; static int check_for_high_segbits; static bool fill_includes_sw_bits; static unsigned int kscratch_used_mask; static inline int __maybe_unused c0_kscratch(void) { switch (current_cpu_type()) { case CPU_XLP: case CPU_XLR: return 22; default: return 31; } } static int allocate_kscratch(void) { int r; unsigned int a = cpu_data[0].kscratch_mask & ~kscratch_used_mask; r = ffs(a); if (r == 0) return -1; r--; /* make it zero based */ kscratch_used_mask |= (1 << r); return r; } static int scratch_reg; int pgd_reg; EXPORT_SYMBOL_GPL(pgd_reg); enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch}; static struct work_registers build_get_work_registers(u32 **p) { struct work_registers r; if (scratch_reg >= 0) { /* Save in CPU local C0_KScratch? */ UASM_i_MTC0(p, 1, c0_kscratch(), scratch_reg); r.r1 = K0; r.r2 = K1; r.r3 = 1; return r; } if (num_possible_cpus() > 1) { /* Get smp_processor_id */ UASM_i_CPUID_MFC0(p, K0, SMP_CPUID_REG); UASM_i_SRL_SAFE(p, K0, K0, SMP_CPUID_REGSHIFT); /* handler_reg_save index in K0 */ UASM_i_SLL(p, K0, K0, ilog2(sizeof(struct tlb_reg_save))); UASM_i_LA(p, K1, (long)&handler_reg_save); UASM_i_ADDU(p, K0, K0, K1); } else { UASM_i_LA(p, K0, (long)&handler_reg_save); } /* K0 now points to save area, save $1 and $2 */ UASM_i_SW(p, 1, offsetof(struct tlb_reg_save, a), K0); UASM_i_SW(p, 2, offsetof(struct tlb_reg_save, b), K0); r.r1 = K1; r.r2 = 1; r.r3 = 2; return r; } static void build_restore_work_registers(u32 **p) { if (scratch_reg >= 0) { uasm_i_ehb(p); UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg); return; } /* K0 already points to save area, restore $1 and $2 */ UASM_i_LW(p, 1, offsetof(struct tlb_reg_save, a), K0); UASM_i_LW(p, 2, offsetof(struct tlb_reg_save, b), K0); } #ifndef CONFIG_MIPS_PGD_C0_CONTEXT /* * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current, * we cannot do r3000 under these circumstances. * * The R3000 TLB handler is simple. */ static void build_r3000_tlb_refill_handler(void) { long pgdc = (long)pgd_current; u32 *p; memset(tlb_handler, 0, sizeof(tlb_handler)); p = tlb_handler; uasm_i_mfc0(&p, K0, C0_BADVADDR); uasm_i_lui(&p, K1, uasm_rel_hi(pgdc)); /* cp0 delay */ uasm_i_lw(&p, K1, uasm_rel_lo(pgdc), K1); uasm_i_srl(&p, K0, K0, 22); /* load delay */ uasm_i_sll(&p, K0, K0, 2); uasm_i_addu(&p, K1, K1, K0); uasm_i_mfc0(&p, K0, C0_CONTEXT); uasm_i_lw(&p, K1, 0, K1); /* cp0 delay */ uasm_i_andi(&p, K0, K0, 0xffc); /* load delay */ uasm_i_addu(&p, K1, K1, K0); uasm_i_lw(&p, K0, 0, K1); uasm_i_nop(&p); /* load delay */ uasm_i_mtc0(&p, K0, C0_ENTRYLO0); uasm_i_mfc0(&p, K1, C0_EPC); /* cp0 delay */ uasm_i_tlbwr(&p); /* cp0 delay */ uasm_i_jr(&p, K1); uasm_i_rfe(&p); /* branch delay */ if (p > tlb_handler + 32) panic("TLB refill handler space exceeded"); pr_debug("Wrote TLB refill handler (%u instructions).\n", (unsigned int)(p - tlb_handler)); memcpy((void *)ebase, tlb_handler, 0x80); local_flush_icache_range(ebase, ebase + 0x80); dump_handler("r3000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x80)); } #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */ /* * The R4000 TLB handler is much more complicated. We have two * consecutive handler areas with 32 instructions space each. * Since they aren't used at the same time, we can overflow in the * other one.To keep things simple, we first assume linear space, * then we relocate it to the final handler layout as needed. */ static u32 final_handler[64]; /* * Hazards * * From the IDT errata for the QED RM5230 (Nevada), processor revision 1.0: * 2. A timing hazard exists for the TLBP instruction. * * stalling_instruction * TLBP * * The JTLB is being read for the TLBP throughout the stall generated by the * previous instruction. This is not really correct as the stalling instruction * can modify the address used to access the JTLB. The failure symptom is that * the TLBP instruction will use an address created for the stalling instruction * and not the address held in C0_ENHI and thus report the wrong results. * * The software work-around is to not allow the instruction preceding the TLBP * to stall - make it an NOP or some other instruction guaranteed not to stall. * * Errata 2 will not be fixed. This errata is also on the R5000. * * As if we MIPS hackers wouldn't know how to nop pipelines happy ... */ static void __maybe_unused build_tlb_probe_entry(u32 **p) { switch (current_cpu_type()) { /* Found by experiment: R4600 v2.0/R4700 needs this, too. */ case CPU_R4600: case CPU_R4700: case CPU_R5000: case CPU_NEVADA: uasm_i_nop(p); uasm_i_tlbp(p); break; default: uasm_i_tlbp(p); break; } } void build_tlb_write_entry(u32 **p, struct uasm_label **l, struct uasm_reloc **r, enum tlb_write_entry wmode) { void(*tlbw)(u32 **) = NULL; switch (wmode) { case tlb_random: tlbw = uasm_i_tlbwr; break; case tlb_indexed: tlbw = uasm_i_tlbwi; break; } if (cpu_has_mips_r2_r6) { if (cpu_has_mips_r2_exec_hazard) uasm_i_ehb(p); tlbw(p); return; } switch (current_cpu_type()) { case CPU_R4000PC: case CPU_R4000SC: case CPU_R4000MC: case CPU_R4400PC: case CPU_R4400SC: case CPU_R4400MC: /* * This branch uses up a mtc0 hazard nop slot and saves * two nops after the tlbw instruction. */ uasm_bgezl_hazard(p, r, hazard_instance); tlbw(p); uasm_bgezl_label(l, p, hazard_instance); hazard_instance++; uasm_i_nop(p); break; case CPU_R4600: case CPU_R4700: uasm_i_nop(p); tlbw(p); uasm_i_nop(p); break; case CPU_R5000: case CPU_NEVADA: uasm_i_nop(p); /* QED specifies 2 nops hazard */ uasm_i_nop(p); /* QED specifies 2 nops hazard */ tlbw(p); break; case CPU_5KC: case CPU_TX49XX: case CPU_PR4450: case CPU_XLR: uasm_i_nop(p); tlbw(p); break; case CPU_R10000: case CPU_R12000: case CPU_R14000: case CPU_R16000: case CPU_4KC: case CPU_4KEC: case CPU_M14KC: case CPU_M14KEC: case CPU_SB1: case CPU_SB1A: case CPU_4KSC: case CPU_20KC: case CPU_25KF: case CPU_BMIPS32: case CPU_BMIPS3300: case CPU_BMIPS4350: case CPU_BMIPS4380: case CPU_BMIPS5000: case CPU_LOONGSON2EF: case CPU_LOONGSON64: case CPU_R5500: if (m4kc_tlbp_war()) uasm_i_nop(p); fallthrough; case CPU_ALCHEMY: tlbw(p); break; case CPU_RM7000: uasm_i_nop(p); uasm_i_nop(p); uasm_i_nop(p); uasm_i_nop(p); tlbw(p); break; case CPU_VR4111: case CPU_VR4121: case CPU_VR4122: case CPU_VR4181: case CPU_VR4181A: uasm_i_nop(p); uasm_i_nop(p); tlbw(p); uasm_i_nop(p); uasm_i_nop(p); break; case CPU_VR4131: case CPU_VR4133: uasm_i_nop(p); uasm_i_nop(p); tlbw(p); break; case CPU_XBURST: tlbw(p); uasm_i_nop(p); break; default: panic("No TLB refill handler yet (CPU type: %d)", current_cpu_type()); break; } } EXPORT_SYMBOL_GPL(build_tlb_write_entry); static __maybe_unused void build_convert_pte_to_entrylo(u32 **p, unsigned int reg) { if (_PAGE_GLOBAL_SHIFT == 0) { /* pte_t is already in EntryLo format */ return; } if (cpu_has_rixi && _PAGE_NO_EXEC != 0) { if (fill_includes_sw_bits) { UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL)); } else { UASM_i_SRL(p, reg, reg, ilog2(_PAGE_NO_EXEC)); UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC)); } } else { #ifdef CONFIG_PHYS_ADDR_T_64BIT uasm_i_dsrl_safe(p, reg, reg, ilog2(_PAGE_GLOBAL)); #else UASM_i_SRL(p, reg, reg, ilog2(_PAGE_GLOBAL)); #endif } } #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT static void build_restore_pagemask(u32 **p, struct uasm_reloc **r, unsigned int tmp, enum label_id lid, int restore_scratch) { if (restore_scratch) { /* * Ensure the MFC0 below observes the value written to the * KScratch register by the prior MTC0. */ if (scratch_reg >= 0) uasm_i_ehb(p); /* Reset default page size */ if (PM_DEFAULT_MASK >> 16) { uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16); uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff); uasm_i_mtc0(p, tmp, C0_PAGEMASK); uasm_il_b(p, r, lid); } else if (PM_DEFAULT_MASK) { uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK); uasm_i_mtc0(p, tmp, C0_PAGEMASK); uasm_il_b(p, r, lid); } else { uasm_i_mtc0(p, 0, C0_PAGEMASK); uasm_il_b(p, r, lid); } if (scratch_reg >= 0) UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg); else UASM_i_LW(p, 1, scratchpad_offset(0), 0); } else { /* Reset default page size */ if (PM_DEFAULT_MASK >> 16) { uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16); uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff); uasm_il_b(p, r, lid); uasm_i_mtc0(p, tmp, C0_PAGEMASK); } else if (PM_DEFAULT_MASK) { uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK); uasm_il_b(p, r, lid); uasm_i_mtc0(p, tmp, C0_PAGEMASK); } else { uasm_il_b(p, r, lid); uasm_i_mtc0(p, 0, C0_PAGEMASK); } } } static void build_huge_tlb_write_entry(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int tmp, enum tlb_write_entry wmode, int restore_scratch) { /* Set huge page tlb entry size */ uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16); uasm_i_ori(p, tmp, tmp, PM_HUGE_MASK & 0xffff); uasm_i_mtc0(p, tmp, C0_PAGEMASK); build_tlb_write_entry(p, l, r, wmode); build_restore_pagemask(p, r, tmp, label_leave, restore_scratch); } /* * Check if Huge PTE is present, if so then jump to LABEL. */ static void build_is_huge_pte(u32 **p, struct uasm_reloc **r, unsigned int tmp, unsigned int pmd, int lid) { UASM_i_LW(p, tmp, 0, pmd); if (use_bbit_insns()) { uasm_il_bbit1(p, r, tmp, ilog2(_PAGE_HUGE), lid); } else { uasm_i_andi(p, tmp, tmp, _PAGE_HUGE); uasm_il_bnez(p, r, tmp, lid); } } static void build_huge_update_entries(u32 **p, unsigned int pte, unsigned int tmp) { int small_sequence; /* * A huge PTE describes an area the size of the * configured huge page size. This is twice the * of the large TLB entry size we intend to use. * A TLB entry half the size of the configured * huge page size is configured into entrylo0 * and entrylo1 to cover the contiguous huge PTE * address space. */ small_sequence = (HPAGE_SIZE >> 7) < 0x10000; /* We can clobber tmp. It isn't used after this.*/ if (!small_sequence) uasm_i_lui(p, tmp, HPAGE_SIZE >> (7 + 16)); build_convert_pte_to_entrylo(p, pte); UASM_i_MTC0(p, pte, C0_ENTRYLO0); /* load it */ /* convert to entrylo1 */ if (small_sequence) UASM_i_ADDIU(p, pte, pte, HPAGE_SIZE >> 7); else UASM_i_ADDU(p, pte, pte, tmp); UASM_i_MTC0(p, pte, C0_ENTRYLO1); /* load it */ } static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r, struct uasm_label **l, unsigned int pte, unsigned int ptr, unsigned int flush) { #ifdef CONFIG_SMP UASM_i_SC(p, pte, 0, ptr); uasm_il_beqz(p, r, pte, label_tlb_huge_update); UASM_i_LW(p, pte, 0, ptr); /* Needed because SC killed our PTE */ #else UASM_i_SW(p, pte, 0, ptr); #endif if (cpu_has_ftlb && flush) { BUG_ON(!cpu_has_tlbinv); UASM_i_MFC0(p, ptr, C0_ENTRYHI); uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV); UASM_i_MTC0(p, ptr, C0_ENTRYHI); build_tlb_write_entry(p, l, r, tlb_indexed); uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV); UASM_i_MTC0(p, ptr, C0_ENTRYHI); build_huge_update_entries(p, pte, ptr); build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0); return; } build_huge_update_entries(p, pte, ptr); build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0); } #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */ #ifdef CONFIG_64BIT /* * TMP and PTR are scratch. * TMP will be clobbered, PTR will hold the pmd entry. */ void build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int tmp, unsigned int ptr) { #ifndef CONFIG_MIPS_PGD_C0_CONTEXT long pgdc = (long)pgd_current; #endif /* * The vmalloc handling is not in the hotpath. */ uasm_i_dmfc0(p, tmp, C0_BADVADDR); if (check_for_high_segbits) { /* * The kernel currently implicitely assumes that the * MIPS SEGBITS parameter for the processor is * (PGDIR_SHIFT+PGDIR_BITS) or less, and will never * allocate virtual addresses outside the maximum * range for SEGBITS = (PGDIR_SHIFT+PGDIR_BITS). But * that doesn't prevent user code from accessing the * higher xuseg addresses. Here, we make sure that * everything but the lower xuseg addresses goes down * the module_alloc/vmalloc path. */ uasm_i_dsrl_safe(p, ptr, tmp, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3); uasm_il_bnez(p, r, ptr, label_vmalloc); } else { uasm_il_bltz(p, r, tmp, label_vmalloc); } /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */ if (pgd_reg != -1) { /* pgd is in pgd_reg */ if (cpu_has_ldpte) UASM_i_MFC0(p, ptr, C0_PWBASE); else UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg); } else { #if defined(CONFIG_MIPS_PGD_C0_CONTEXT) /* * &pgd << 11 stored in CONTEXT [23..63]. */ UASM_i_MFC0(p, ptr, C0_CONTEXT); /* Clear lower 23 bits of context. */ uasm_i_dins(p, ptr, 0, 0, 23); /* 1 0 1 0 1 << 6 xkphys cached */ uasm_i_ori(p, ptr, ptr, 0x540); uasm_i_drotr(p, ptr, ptr, 11); #elif defined(CONFIG_SMP) UASM_i_CPUID_MFC0(p, ptr, SMP_CPUID_REG); uasm_i_dsrl_safe(p, ptr, ptr, SMP_CPUID_PTRSHIFT); UASM_i_LA_mostly(p, tmp, pgdc); uasm_i_daddu(p, ptr, ptr, tmp); uasm_i_dmfc0(p, tmp, C0_BADVADDR); uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr); #else UASM_i_LA_mostly(p, ptr, pgdc); uasm_i_ld(p, ptr, uasm_rel_lo(pgdc), ptr); #endif } uasm_l_vmalloc_done(l, *p); /* get pgd offset in bytes */ uasm_i_dsrl_safe(p, tmp, tmp, PGDIR_SHIFT - 3); uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3); uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */ #ifndef __PAGETABLE_PUD_FOLDED uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */ uasm_i_ld(p, ptr, 0, ptr); /* get pud pointer */ uasm_i_dsrl_safe(p, tmp, tmp, PUD_SHIFT - 3); /* get pud offset in bytes */ uasm_i_andi(p, tmp, tmp, (PTRS_PER_PUD - 1) << 3); uasm_i_daddu(p, ptr, ptr, tmp); /* add in pud offset */ #endif #ifndef __PAGETABLE_PMD_FOLDED uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */ uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */ uasm_i_dsrl_safe(p, tmp, tmp, PMD_SHIFT-3); /* get pmd offset in bytes */ uasm_i_andi(p, tmp, tmp, (PTRS_PER_PMD - 1)<<3); uasm_i_daddu(p, ptr, ptr, tmp); /* add in pmd offset */ #endif } EXPORT_SYMBOL_GPL(build_get_pmde64); /* * BVADDR is the faulting address, PTR is scratch. * PTR will hold the pgd for vmalloc. */ static void build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int bvaddr, unsigned int ptr, enum vmalloc64_mode mode) { long swpd = (long)swapper_pg_dir; int single_insn_swpd; int did_vmalloc_branch = 0; single_insn_swpd = uasm_in_compat_space_p(swpd) && !uasm_rel_lo(swpd); uasm_l_vmalloc(l, *p); if (mode != not_refill && check_for_high_segbits) { if (single_insn_swpd) { uasm_il_bltz(p, r, bvaddr, label_vmalloc_done); uasm_i_lui(p, ptr, uasm_rel_hi(swpd)); did_vmalloc_branch = 1; /* fall through */ } else { uasm_il_bgez(p, r, bvaddr, label_large_segbits_fault); } } if (!did_vmalloc_branch) { if (single_insn_swpd) { uasm_il_b(p, r, label_vmalloc_done); uasm_i_lui(p, ptr, uasm_rel_hi(swpd)); } else { UASM_i_LA_mostly(p, ptr, swpd); uasm_il_b(p, r, label_vmalloc_done); if (uasm_in_compat_space_p(swpd)) uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(swpd)); else uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd)); } } if (mode != not_refill && check_for_high_segbits) { uasm_l_large_segbits_fault(l, *p); if (mode == refill_scratch && scratch_reg >= 0) uasm_i_ehb(p); /* * We get here if we are an xsseg address, or if we are * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary. * * Ignoring xsseg (assume disabled so would generate * (address errors?), the only remaining possibility * is the upper xuseg addresses. On processors with * TLB_SEGBITS <= PGDIR_SHIFT+PGDIR_BITS, these * addresses would have taken an address error. We try * to mimic that here by taking a load/istream page * fault. */ if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) uasm_i_sync(p, 0); UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0); uasm_i_jr(p, ptr); if (mode == refill_scratch) { if (scratch_reg >= 0) UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg); else UASM_i_LW(p, 1, scratchpad_offset(0), 0); } else { uasm_i_nop(p); } } } #else /* !CONFIG_64BIT */ /* * TMP and PTR are scratch. * TMP will be clobbered, PTR will hold the pgd entry. */ void build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr) { if (pgd_reg != -1) { /* pgd is in pgd_reg */ uasm_i_mfc0(p, ptr, c0_kscratch(), pgd_reg); uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */ } else { long pgdc = (long)pgd_current; /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */ #ifdef CONFIG_SMP uasm_i_mfc0(p, ptr, SMP_CPUID_REG); UASM_i_LA_mostly(p, tmp, pgdc); uasm_i_srl(p, ptr, ptr, SMP_CPUID_PTRSHIFT); uasm_i_addu(p, ptr, tmp, ptr); #else UASM_i_LA_mostly(p, ptr, pgdc); #endif uasm_i_mfc0(p, tmp, C0_BADVADDR); /* get faulting address */ uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr); } uasm_i_srl(p, tmp, tmp, PGDIR_SHIFT); /* get pgd only bits */ uasm_i_sll(p, tmp, tmp, PGD_T_LOG2); uasm_i_addu(p, ptr, ptr, tmp); /* add in pgd offset */ } EXPORT_SYMBOL_GPL(build_get_pgde32); #endif /* !CONFIG_64BIT */ static void build_adjust_context(u32 **p, unsigned int ctx) { unsigned int shift = 4 - (PTE_T_LOG2 + 1) + PAGE_SHIFT - 12; unsigned int mask = (PTRS_PER_PTE / 2 - 1) << (PTE_T_LOG2 + 1); switch (current_cpu_type()) { case CPU_VR41XX: case CPU_VR4111: case CPU_VR4121: case CPU_VR4122: case CPU_VR4131: case CPU_VR4181: case CPU_VR4181A: case CPU_VR4133: shift += 2; break; default: break; } if (shift) UASM_i_SRL(p, ctx, ctx, shift); uasm_i_andi(p, ctx, ctx, mask); } void build_get_ptep(u32 **p, unsigned int tmp, unsigned int ptr) { /* * Bug workaround for the Nevada. It seems as if under certain * circumstances the move from cp0_context might produce a * bogus result when the mfc0 instruction and its consumer are * in a different cacheline or a load instruction, probably any * memory reference, is between them. */ switch (current_cpu_type()) { case CPU_NEVADA: UASM_i_LW(p, ptr, 0, ptr); GET_CONTEXT(p, tmp); /* get context reg */ break; default: GET_CONTEXT(p, tmp); /* get context reg */ UASM_i_LW(p, ptr, 0, ptr); break; } build_adjust_context(p, tmp); UASM_i_ADDU(p, ptr, ptr, tmp); /* add in offset */ } EXPORT_SYMBOL_GPL(build_get_ptep); void build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep) { int pte_off_even = 0; int pte_off_odd = sizeof(pte_t); #if defined(CONFIG_CPU_MIPS32) && defined(CONFIG_PHYS_ADDR_T_64BIT) /* The low 32 bits of EntryLo is stored in pte_high */ pte_off_even += offsetof(pte_t, pte_high); pte_off_odd += offsetof(pte_t, pte_high); #endif if (IS_ENABLED(CONFIG_XPA)) { uasm_i_lw(p, tmp, pte_off_even, ptep); /* even pte */ UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL)); UASM_i_MTC0(p, tmp, C0_ENTRYLO0); if (cpu_has_xpa && !mips_xpa_disabled) { uasm_i_lw(p, tmp, 0, ptep); uasm_i_ext(p, tmp, tmp, 0, 24); uasm_i_mthc0(p, tmp, C0_ENTRYLO0); } uasm_i_lw(p, tmp, pte_off_odd, ptep); /* odd pte */ UASM_i_ROTR(p, tmp, tmp, ilog2(_PAGE_GLOBAL)); UASM_i_MTC0(p, tmp, C0_ENTRYLO1); if (cpu_has_xpa && !mips_xpa_disabled) { uasm_i_lw(p, tmp, sizeof(pte_t), ptep); uasm_i_ext(p, tmp, tmp, 0, 24); uasm_i_mthc0(p, tmp, C0_ENTRYLO1); } return; } UASM_i_LW(p, tmp, pte_off_even, ptep); /* get even pte */ UASM_i_LW(p, ptep, pte_off_odd, ptep); /* get odd pte */ if (r45k_bvahwbug()) build_tlb_probe_entry(p); build_convert_pte_to_entrylo(p, tmp); if (r4k_250MHZhwbug()) UASM_i_MTC0(p, 0, C0_ENTRYLO0); UASM_i_MTC0(p, tmp, C0_ENTRYLO0); /* load it */ build_convert_pte_to_entrylo(p, ptep); if (r45k_bvahwbug()) uasm_i_mfc0(p, tmp, C0_INDEX); if (r4k_250MHZhwbug()) UASM_i_MTC0(p, 0, C0_ENTRYLO1); UASM_i_MTC0(p, ptep, C0_ENTRYLO1); /* load it */ } EXPORT_SYMBOL_GPL(build_update_entries); struct mips_huge_tlb_info { int huge_pte; int restore_scratch; bool need_reload_pte; }; static struct mips_huge_tlb_info build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int tmp, unsigned int ptr, int c0_scratch_reg) { struct mips_huge_tlb_info rv; unsigned int even, odd; int vmalloc_branch_delay_filled = 0; const int scratch = 1; /* Our extra working register */ rv.huge_pte = scratch; rv.restore_scratch = 0; rv.need_reload_pte = false; if (check_for_high_segbits) { UASM_i_MFC0(p, tmp, C0_BADVADDR); if (pgd_reg != -1) UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg); else UASM_i_MFC0(p, ptr, C0_CONTEXT); if (c0_scratch_reg >= 0) UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg); else UASM_i_SW(p, scratch, scratchpad_offset(0), 0); uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3); uasm_il_bnez(p, r, scratch, label_vmalloc); if (pgd_reg == -1) { vmalloc_branch_delay_filled = 1; /* Clear lower 23 bits of context. */ uasm_i_dins(p, ptr, 0, 0, 23); } } else { if (pgd_reg != -1) UASM_i_MFC0(p, ptr, c0_kscratch(), pgd_reg); else UASM_i_MFC0(p, ptr, C0_CONTEXT); UASM_i_MFC0(p, tmp, C0_BADVADDR); if (c0_scratch_reg >= 0) UASM_i_MTC0(p, scratch, c0_kscratch(), c0_scratch_reg); else UASM_i_SW(p, scratch, scratchpad_offset(0), 0); if (pgd_reg == -1) /* Clear lower 23 bits of context. */ uasm_i_dins(p, ptr, 0, 0, 23); uasm_il_bltz(p, r, tmp, label_vmalloc); } if (pgd_reg == -1) { vmalloc_branch_delay_filled = 1; /* 1 0 1 0 1 << 6 xkphys cached */ uasm_i_ori(p, ptr, ptr, 0x540); uasm_i_drotr(p, ptr, ptr, 11); } #ifdef __PAGETABLE_PMD_FOLDED #define LOC_PTEP scratch #else #define LOC_PTEP ptr #endif if (!vmalloc_branch_delay_filled) /* get pgd offset in bytes */ uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3); uasm_l_vmalloc_done(l, *p); /* * tmp ptr * fall-through case = badvaddr *pgd_current * vmalloc case = badvaddr swapper_pg_dir */ if (vmalloc_branch_delay_filled) /* get pgd offset in bytes */ uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3); #ifdef __PAGETABLE_PMD_FOLDED GET_CONTEXT(p, tmp); /* get context reg */ #endif uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3); if (use_lwx_insns()) { UASM_i_LWX(p, LOC_PTEP, scratch, ptr); } else { uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */ uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */ } #ifndef __PAGETABLE_PUD_FOLDED /* get pud offset in bytes */ uasm_i_dsrl_safe(p, scratch, tmp, PUD_SHIFT - 3); uasm_i_andi(p, scratch, scratch, (PTRS_PER_PUD - 1) << 3); if (use_lwx_insns()) { UASM_i_LWX(p, ptr, scratch, ptr); } else { uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */ UASM_i_LW(p, ptr, 0, ptr); } /* ptr contains a pointer to PMD entry */ /* tmp contains the address */ #endif #ifndef __PAGETABLE_PMD_FOLDED /* get pmd offset in bytes */ uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3); uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3); GET_CONTEXT(p, tmp); /* get context reg */ if (use_lwx_insns()) { UASM_i_LWX(p, scratch, scratch, ptr); } else { uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */ UASM_i_LW(p, scratch, 0, ptr); } #endif /* Adjust the context during the load latency. */ build_adjust_context(p, tmp); #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update); /* * The in the LWX case we don't want to do the load in the * delay slot. It cannot issue in the same cycle and may be * speculative and unneeded. */ if (use_lwx_insns()) uasm_i_nop(p); #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */ /* build_update_entries */ if (use_lwx_insns()) { even = ptr; odd = tmp; UASM_i_LWX(p, even, scratch, tmp); UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t)); UASM_i_LWX(p, odd, scratch, tmp); } else { UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */ even = tmp; odd = ptr; UASM_i_LW(p, even, 0, ptr); /* get even pte */ UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */ } if (cpu_has_rixi) { uasm_i_drotr(p, even, even, ilog2(_PAGE_GLOBAL)); UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */ uasm_i_drotr(p, odd, odd, ilog2(_PAGE_GLOBAL)); } else { uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL)); UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */ uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL)); } UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */ if (c0_scratch_reg >= 0) { uasm_i_ehb(p); UASM_i_MFC0(p, scratch, c0_kscratch(), c0_scratch_reg); build_tlb_write_entry(p, l, r, tlb_random); uasm_l_leave(l, *p); rv.restore_scratch = 1; } else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) { build_tlb_write_entry(p, l, r, tlb_random); uasm_l_leave(l, *p); UASM_i_LW(p, scratch, scratchpad_offset(0), 0); } else { UASM_i_LW(p, scratch, scratchpad_offset(0), 0); build_tlb_write_entry(p, l, r, tlb_random); uasm_l_leave(l, *p); rv.restore_scratch = 1; } uasm_i_eret(p); /* return from trap */ return rv; } /* * For a 64-bit kernel, we are using the 64-bit XTLB refill exception * because EXL == 0. If we wrap, we can also use the 32 instruction * slots before the XTLB refill exception handler which belong to the * unused TLB refill exception. */ #define MIPS64_REFILL_INSNS 32 static void build_r4000_tlb_refill_handler(void) { u32 *p = tlb_handler; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; u32 *f; unsigned int final_len; struct mips_huge_tlb_info htlb_info __maybe_unused; enum vmalloc64_mode vmalloc_mode __maybe_unused; memset(tlb_handler, 0, sizeof(tlb_handler)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); memset(final_handler, 0, sizeof(final_handler)); if (IS_ENABLED(CONFIG_64BIT) && (scratch_reg >= 0 || scratchpad_available()) && use_bbit_insns()) { htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1, scratch_reg); vmalloc_mode = refill_scratch; } else { htlb_info.huge_pte = K0; htlb_info.restore_scratch = 0; htlb_info.need_reload_pte = true; vmalloc_mode = refill_noscratch; /* * create the plain linear handler */ if (bcm1250_m3_war()) { unsigned int segbits = 44; uasm_i_dmfc0(&p, K0, C0_BADVADDR); uasm_i_dmfc0(&p, K1, C0_ENTRYHI); uasm_i_xor(&p, K0, K0, K1); uasm_i_dsrl_safe(&p, K1, K0, 62); uasm_i_dsrl_safe(&p, K0, K0, 12 + 1); uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits); uasm_i_or(&p, K0, K0, K1); uasm_il_bnez(&p, &r, K0, label_leave); /* No need for uasm_i_nop */ } #ifdef CONFIG_64BIT build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */ #else build_get_pgde32(&p, K0, K1); /* get pgd in K1 */ #endif #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update); #endif build_get_ptep(&p, K0, K1); build_update_entries(&p, K0, K1); build_tlb_write_entry(&p, &l, &r, tlb_random); uasm_l_leave(&l, p); uasm_i_eret(&p); /* return from trap */ } #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT uasm_l_tlb_huge_update(&l, p); if (htlb_info.need_reload_pte) UASM_i_LW(&p, htlb_info.huge_pte, 0, K1); build_huge_update_entries(&p, htlb_info.huge_pte, K1); build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random, htlb_info.restore_scratch); #endif #ifdef CONFIG_64BIT build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode); #endif /* * Overflow check: For the 64bit handler, we need at least one * free instruction slot for the wrap-around branch. In worst * case, if the intended insertion point is a delay slot, we * need three, with the second nop'ed and the third being * unused. */ switch (boot_cpu_type()) { default: if (sizeof(long) == 4) { case CPU_LOONGSON2EF: /* Loongson2 ebase is different than r4k, we have more space */ if ((p - tlb_handler) > 64) panic("TLB refill handler space exceeded"); /* * Now fold the handler in the TLB refill handler space. */ f = final_handler; /* Simplest case, just copy the handler. */ uasm_copy_handler(relocs, labels, tlb_handler, p, f); final_len = p - tlb_handler; break; } else { if (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 1) || (((p - tlb_handler) > (MIPS64_REFILL_INSNS * 2) - 3) && uasm_insn_has_bdelay(relocs, tlb_handler + MIPS64_REFILL_INSNS - 3))) panic("TLB refill handler space exceeded"); /* * Now fold the handler in the TLB refill handler space. */ f = final_handler + MIPS64_REFILL_INSNS; if ((p - tlb_handler) <= MIPS64_REFILL_INSNS) { /* Just copy the handler. */ uasm_copy_handler(relocs, labels, tlb_handler, p, f); final_len = p - tlb_handler; } else { #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT const enum label_id ls = label_tlb_huge_update; #else const enum label_id ls = label_vmalloc; #endif u32 *split; int ov = 0; int i; for (i = 0; i < ARRAY_SIZE(labels) && labels[i].lab != ls; i++) ; BUG_ON(i == ARRAY_SIZE(labels)); split = labels[i].addr; /* * See if we have overflown one way or the other. */ if (split > tlb_handler + MIPS64_REFILL_INSNS || split < p - MIPS64_REFILL_INSNS) ov = 1; if (ov) { /* * Split two instructions before the end. One * for the branch and one for the instruction * in the delay slot. */ split = tlb_handler + MIPS64_REFILL_INSNS - 2; /* * If the branch would fall in a delay slot, * we must back up an additional instruction * so that it is no longer in a delay slot. */ if (uasm_insn_has_bdelay(relocs, split - 1)) split--; } /* Copy first part of the handler. */ uasm_copy_handler(relocs, labels, tlb_handler, split, f); f += split - tlb_handler; if (ov) { /* Insert branch. */ uasm_l_split(&l, final_handler); uasm_il_b(&f, &r, label_split); if (uasm_insn_has_bdelay(relocs, split)) uasm_i_nop(&f); else { uasm_copy_handler(relocs, labels, split, split + 1, f); uasm_move_labels(labels, f, f + 1, -1); f++; split++; } } /* Copy the rest of the handler. */ uasm_copy_handler(relocs, labels, split, p, final_handler); final_len = (f - (final_handler + MIPS64_REFILL_INSNS)) + (p - split); } } break; } uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB refill handler (%u instructions).\n", final_len); memcpy((void *)ebase, final_handler, 0x100); local_flush_icache_range(ebase, ebase + 0x100); dump_handler("r4000_tlb_refill", (u32 *)ebase, (u32 *)(ebase + 0x100)); } static void setup_pw(void) { unsigned int pwctl; unsigned long pgd_i, pgd_w; #ifndef __PAGETABLE_PMD_FOLDED unsigned long pmd_i, pmd_w; #endif unsigned long pt_i, pt_w; unsigned long pte_i, pte_w; #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT unsigned long psn; psn = ilog2(_PAGE_HUGE); /* bit used to indicate huge page */ #endif pgd_i = PGDIR_SHIFT; /* 1st level PGD */ #ifndef __PAGETABLE_PMD_FOLDED pgd_w = PGDIR_SHIFT - PMD_SHIFT + PGD_ORDER; pmd_i = PMD_SHIFT; /* 2nd level PMD */ pmd_w = PMD_SHIFT - PAGE_SHIFT; #else pgd_w = PGDIR_SHIFT - PAGE_SHIFT + PGD_ORDER; #endif pt_i = PAGE_SHIFT; /* 3rd level PTE */ pt_w = PAGE_SHIFT - 3; pte_i = ilog2(_PAGE_GLOBAL); pte_w = 0; pwctl = 1 << 30; /* Set PWDirExt */ #ifndef __PAGETABLE_PMD_FOLDED write_c0_pwfield(pgd_i << 24 | pmd_i << 12 | pt_i << 6 | pte_i); write_c0_pwsize(1 << 30 | pgd_w << 24 | pmd_w << 12 | pt_w << 6 | pte_w); #else write_c0_pwfield(pgd_i << 24 | pt_i << 6 | pte_i); write_c0_pwsize(1 << 30 | pgd_w << 24 | pt_w << 6 | pte_w); #endif #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT pwctl |= (1 << 6 | psn); #endif write_c0_pwctl(pwctl); write_c0_kpgd((long)swapper_pg_dir); kscratch_used_mask |= (1 << 7); /* KScratch6 is used for KPGD */ } static void build_loongson3_tlb_refill_handler(void) { u32 *p = tlb_handler; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); memset(tlb_handler, 0, sizeof(tlb_handler)); if (check_for_high_segbits) { uasm_i_dmfc0(&p, K0, C0_BADVADDR); uasm_i_dsrl_safe(&p, K1, K0, PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3); uasm_il_beqz(&p, &r, K1, label_vmalloc); uasm_i_nop(&p); uasm_il_bgez(&p, &r, K0, label_large_segbits_fault); uasm_i_nop(&p); uasm_l_vmalloc(&l, p); } uasm_i_dmfc0(&p, K1, C0_PGD); uasm_i_lddir(&p, K0, K1, 3); /* global page dir */ #ifndef __PAGETABLE_PMD_FOLDED uasm_i_lddir(&p, K1, K0, 1); /* middle page dir */ #endif uasm_i_ldpte(&p, K1, 0); /* even */ uasm_i_ldpte(&p, K1, 1); /* odd */ uasm_i_tlbwr(&p); /* restore page mask */ if (PM_DEFAULT_MASK >> 16) { uasm_i_lui(&p, K0, PM_DEFAULT_MASK >> 16); uasm_i_ori(&p, K0, K0, PM_DEFAULT_MASK & 0xffff); uasm_i_mtc0(&p, K0, C0_PAGEMASK); } else if (PM_DEFAULT_MASK) { uasm_i_ori(&p, K0, 0, PM_DEFAULT_MASK); uasm_i_mtc0(&p, K0, C0_PAGEMASK); } else { uasm_i_mtc0(&p, 0, C0_PAGEMASK); } uasm_i_eret(&p); if (check_for_high_segbits) { uasm_l_large_segbits_fault(&l, p); UASM_i_LA(&p, K1, (unsigned long)tlb_do_page_fault_0); uasm_i_jr(&p, K1); uasm_i_nop(&p); } uasm_resolve_relocs(relocs, labels); memcpy((void *)(ebase + 0x80), tlb_handler, 0x80); local_flush_icache_range(ebase + 0x80, ebase + 0x100); dump_handler("loongson3_tlb_refill", (u32 *)(ebase + 0x80), (u32 *)(ebase + 0x100)); } static void build_setup_pgd(void) { const int a0 = 4; const int __maybe_unused a1 = 5; const int __maybe_unused a2 = 6; u32 *p = (u32 *)msk_isa16_mode((ulong)tlbmiss_handler_setup_pgd); #ifndef CONFIG_MIPS_PGD_C0_CONTEXT long pgdc = (long)pgd_current; #endif memset(p, 0, tlbmiss_handler_setup_pgd_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); pgd_reg = allocate_kscratch(); #ifdef CONFIG_MIPS_PGD_C0_CONTEXT if (pgd_reg == -1) { struct uasm_label *l = labels; struct uasm_reloc *r = relocs; /* PGD << 11 in c0_Context */ /* * If it is a ckseg0 address, convert to a physical * address. Shifting right by 29 and adding 4 will * result in zero for these addresses. * */ UASM_i_SRA(&p, a1, a0, 29); UASM_i_ADDIU(&p, a1, a1, 4); uasm_il_bnez(&p, &r, a1, label_tlbl_goaround1); uasm_i_nop(&p); uasm_i_dinsm(&p, a0, 0, 29, 64 - 29); uasm_l_tlbl_goaround1(&l, p); UASM_i_SLL(&p, a0, a0, 11); UASM_i_MTC0(&p, a0, C0_CONTEXT); uasm_i_jr(&p, 31); uasm_i_ehb(&p); } else { /* PGD in c0_KScratch */ if (cpu_has_ldpte) UASM_i_MTC0(&p, a0, C0_PWBASE); else UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg); uasm_i_jr(&p, 31); uasm_i_ehb(&p); } #else #ifdef CONFIG_SMP /* Save PGD to pgd_current[smp_processor_id()] */ UASM_i_CPUID_MFC0(&p, a1, SMP_CPUID_REG); UASM_i_SRL_SAFE(&p, a1, a1, SMP_CPUID_PTRSHIFT); UASM_i_LA_mostly(&p, a2, pgdc); UASM_i_ADDU(&p, a2, a2, a1); UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2); #else UASM_i_LA_mostly(&p, a2, pgdc); UASM_i_SW(&p, a0, uasm_rel_lo(pgdc), a2); #endif /* SMP */ /* if pgd_reg is allocated, save PGD also to scratch register */ if (pgd_reg != -1) { UASM_i_MTC0(&p, a0, c0_kscratch(), pgd_reg); uasm_i_jr(&p, 31); uasm_i_ehb(&p); } else { uasm_i_jr(&p, 31); uasm_i_nop(&p); } #endif if (p >= (u32 *)tlbmiss_handler_setup_pgd_end) panic("tlbmiss_handler_setup_pgd space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote tlbmiss_handler_setup_pgd (%u instructions).\n", (unsigned int)(p - (u32 *)tlbmiss_handler_setup_pgd)); dump_handler("tlbmiss_handler", tlbmiss_handler_setup_pgd, tlbmiss_handler_setup_pgd_end); } static void iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr) { #ifdef CONFIG_SMP if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) uasm_i_sync(p, 0); # ifdef CONFIG_PHYS_ADDR_T_64BIT if (cpu_has_64bits) uasm_i_lld(p, pte, 0, ptr); else # endif UASM_i_LL(p, pte, 0, ptr); #else # ifdef CONFIG_PHYS_ADDR_T_64BIT if (cpu_has_64bits) uasm_i_ld(p, pte, 0, ptr); else # endif UASM_i_LW(p, pte, 0, ptr); #endif } static void iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, unsigned int mode, unsigned int scratch) { unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY); unsigned int swmode = mode & ~hwmode; if (IS_ENABLED(CONFIG_XPA) && !cpu_has_64bits) { uasm_i_lui(p, scratch, swmode >> 16); uasm_i_or(p, pte, pte, scratch); BUG_ON(swmode & 0xffff); } else { uasm_i_ori(p, pte, pte, mode); } #ifdef CONFIG_SMP # ifdef CONFIG_PHYS_ADDR_T_64BIT if (cpu_has_64bits) uasm_i_scd(p, pte, 0, ptr); else # endif UASM_i_SC(p, pte, 0, ptr); if (r10000_llsc_war()) uasm_il_beqzl(p, r, pte, label_smp_pgtable_change); else uasm_il_beqz(p, r, pte, label_smp_pgtable_change); # ifdef CONFIG_PHYS_ADDR_T_64BIT if (!cpu_has_64bits) { /* no uasm_i_nop needed */ uasm_i_ll(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_ori(p, pte, pte, hwmode); BUG_ON(hwmode & ~0xffff); uasm_i_sc(p, pte, sizeof(pte_t) / 2, ptr); uasm_il_beqz(p, r, pte, label_smp_pgtable_change); /* no uasm_i_nop needed */ uasm_i_lw(p, pte, 0, ptr); } else uasm_i_nop(p); # else uasm_i_nop(p); # endif #else # ifdef CONFIG_PHYS_ADDR_T_64BIT if (cpu_has_64bits) uasm_i_sd(p, pte, 0, ptr); else # endif UASM_i_SW(p, pte, 0, ptr); # ifdef CONFIG_PHYS_ADDR_T_64BIT if (!cpu_has_64bits) { uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_ori(p, pte, pte, hwmode); BUG_ON(hwmode & ~0xffff); uasm_i_sw(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_lw(p, pte, 0, ptr); } # endif #endif } /* * Check if PTE is present, if not then jump to LABEL. PTR points to * the page table where this PTE is located, PTE will be re-loaded * with it's original value. */ static void build_pte_present(u32 **p, struct uasm_reloc **r, int pte, int ptr, int scratch, enum label_id lid) { int t = scratch >= 0 ? scratch : pte; int cur = pte; if (cpu_has_rixi) { if (use_bbit_insns()) { uasm_il_bbit0(p, r, pte, ilog2(_PAGE_PRESENT), lid); uasm_i_nop(p); } else { if (_PAGE_PRESENT_SHIFT) { uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT); cur = t; } uasm_i_andi(p, t, cur, 1); uasm_il_beqz(p, r, t, lid); if (pte == t) /* You lose the SMP race :-(*/ iPTE_LW(p, pte, ptr); } } else { if (_PAGE_PRESENT_SHIFT) { uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT); cur = t; } uasm_i_andi(p, t, cur, (_PAGE_PRESENT | _PAGE_NO_READ) >> _PAGE_PRESENT_SHIFT); uasm_i_xori(p, t, t, _PAGE_PRESENT >> _PAGE_PRESENT_SHIFT); uasm_il_bnez(p, r, t, lid); if (pte == t) /* You lose the SMP race :-(*/ iPTE_LW(p, pte, ptr); } } /* Make PTE valid, store result in PTR. */ static void build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, unsigned int scratch) { unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED; iPTE_SW(p, r, pte, ptr, mode, scratch); } /* * Check if PTE can be written to, if not branch to LABEL. Regardless * restore PTE with value from PTR when done. */ static void build_pte_writable(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, int scratch, enum label_id lid) { int t = scratch >= 0 ? scratch : pte; int cur = pte; if (_PAGE_PRESENT_SHIFT) { uasm_i_srl(p, t, cur, _PAGE_PRESENT_SHIFT); cur = t; } uasm_i_andi(p, t, cur, (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT); uasm_i_xori(p, t, t, (_PAGE_PRESENT | _PAGE_WRITE) >> _PAGE_PRESENT_SHIFT); uasm_il_bnez(p, r, t, lid); if (pte == t) /* You lose the SMP race :-(*/ iPTE_LW(p, pte, ptr); else uasm_i_nop(p); } /* Make PTE writable, update software status bits as well, then store * at PTR. */ static void build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, unsigned int scratch) { unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); iPTE_SW(p, r, pte, ptr, mode, scratch); } /* * Check if PTE can be modified, if not branch to LABEL. Regardless * restore PTE with value from PTR when done. */ static void build_pte_modifiable(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, int scratch, enum label_id lid) { if (use_bbit_insns()) { uasm_il_bbit0(p, r, pte, ilog2(_PAGE_WRITE), lid); uasm_i_nop(p); } else { int t = scratch >= 0 ? scratch : pte; uasm_i_srl(p, t, pte, _PAGE_WRITE_SHIFT); uasm_i_andi(p, t, t, 1); uasm_il_beqz(p, r, t, lid); if (pte == t) /* You lose the SMP race :-(*/ iPTE_LW(p, pte, ptr); } } #ifndef CONFIG_MIPS_PGD_C0_CONTEXT /* * R3000 style TLB load/store/modify handlers. */ /* * This places the pte into ENTRYLO0 and writes it with tlbwi. * Then it returns. */ static void build_r3000_pte_reload_tlbwi(u32 **p, unsigned int pte, unsigned int tmp) { uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */ uasm_i_mfc0(p, tmp, C0_EPC); /* cp0 delay */ uasm_i_tlbwi(p); uasm_i_jr(p, tmp); uasm_i_rfe(p); /* branch delay */ } /* * This places the pte into ENTRYLO0 and writes it with tlbwi * or tlbwr as appropriate. This is because the index register * may have the probe fail bit set as a result of a trap on a * kseg2 access, i.e. without refill. Then it returns. */ static void build_r3000_tlb_reload_write(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int pte, unsigned int tmp) { uasm_i_mfc0(p, tmp, C0_INDEX); uasm_i_mtc0(p, pte, C0_ENTRYLO0); /* cp0 delay */ uasm_il_bltz(p, r, tmp, label_r3000_write_probe_fail); /* cp0 delay */ uasm_i_mfc0(p, tmp, C0_EPC); /* branch delay */ uasm_i_tlbwi(p); /* cp0 delay */ uasm_i_jr(p, tmp); uasm_i_rfe(p); /* branch delay */ uasm_l_r3000_write_probe_fail(l, *p); uasm_i_tlbwr(p); /* cp0 delay */ uasm_i_jr(p, tmp); uasm_i_rfe(p); /* branch delay */ } static void build_r3000_tlbchange_handler_head(u32 **p, unsigned int pte, unsigned int ptr) { long pgdc = (long)pgd_current; uasm_i_mfc0(p, pte, C0_BADVADDR); uasm_i_lui(p, ptr, uasm_rel_hi(pgdc)); /* cp0 delay */ uasm_i_lw(p, ptr, uasm_rel_lo(pgdc), ptr); uasm_i_srl(p, pte, pte, 22); /* load delay */ uasm_i_sll(p, pte, pte, 2); uasm_i_addu(p, ptr, ptr, pte); uasm_i_mfc0(p, pte, C0_CONTEXT); uasm_i_lw(p, ptr, 0, ptr); /* cp0 delay */ uasm_i_andi(p, pte, pte, 0xffc); /* load delay */ uasm_i_addu(p, ptr, ptr, pte); uasm_i_lw(p, pte, 0, ptr); uasm_i_tlbp(p); /* load delay */ } static void build_r3000_tlb_load_handler(void) { u32 *p = (u32 *)handle_tlbl; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(p, 0, handle_tlbl_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r3000_tlbchange_handler_head(&p, K0, K1); build_pte_present(&p, &r, K0, K1, -1, label_nopage_tlbl); uasm_i_nop(&p); /* load delay */ build_make_valid(&p, &r, K0, K1, -1); build_r3000_tlb_reload_write(&p, &l, &r, K0, K1); uasm_l_nopage_tlbl(&l, p); uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff); uasm_i_nop(&p); if (p >= (u32 *)handle_tlbl_end) panic("TLB load handler fastpath space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB load handler fastpath (%u instructions).\n", (unsigned int)(p - (u32 *)handle_tlbl)); dump_handler("r3000_tlb_load", handle_tlbl, handle_tlbl_end); } static void build_r3000_tlb_store_handler(void) { u32 *p = (u32 *)handle_tlbs; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(p, 0, handle_tlbs_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r3000_tlbchange_handler_head(&p, K0, K1); build_pte_writable(&p, &r, K0, K1, -1, label_nopage_tlbs); uasm_i_nop(&p); /* load delay */ build_make_write(&p, &r, K0, K1, -1); build_r3000_tlb_reload_write(&p, &l, &r, K0, K1); uasm_l_nopage_tlbs(&l, p); uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff); uasm_i_nop(&p); if (p >= (u32 *)handle_tlbs_end) panic("TLB store handler fastpath space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB store handler fastpath (%u instructions).\n", (unsigned int)(p - (u32 *)handle_tlbs)); dump_handler("r3000_tlb_store", handle_tlbs, handle_tlbs_end); } static void build_r3000_tlb_modify_handler(void) { u32 *p = (u32 *)handle_tlbm; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(p, 0, handle_tlbm_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r3000_tlbchange_handler_head(&p, K0, K1); build_pte_modifiable(&p, &r, K0, K1, -1, label_nopage_tlbm); uasm_i_nop(&p); /* load delay */ build_make_write(&p, &r, K0, K1, -1); build_r3000_pte_reload_tlbwi(&p, K0, K1); uasm_l_nopage_tlbm(&l, p); uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff); uasm_i_nop(&p); if (p >= (u32 *)handle_tlbm_end) panic("TLB modify handler fastpath space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n", (unsigned int)(p - (u32 *)handle_tlbm)); dump_handler("r3000_tlb_modify", handle_tlbm, handle_tlbm_end); } #endif /* CONFIG_MIPS_PGD_C0_CONTEXT */ static bool cpu_has_tlbex_tlbp_race(void) { /* * When a Hardware Table Walker is running it can replace TLB entries * at any time, leading to a race between it & the CPU. */ if (cpu_has_htw) return true; /* * If the CPU shares FTLB RAM with its siblings then our entry may be * replaced at any time by a sibling performing a write to the FTLB. */ if (cpu_has_shared_ftlb_ram) return true; /* In all other cases there ought to be no race condition to handle */ return false; } /* * R4000 style TLB load/store/modify handlers. */ static struct work_registers build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l, struct uasm_reloc **r) { struct work_registers wr = build_get_work_registers(p); #ifdef CONFIG_64BIT build_get_pmde64(p, l, r, wr.r1, wr.r2); /* get pmd in ptr */ #else build_get_pgde32(p, wr.r1, wr.r2); /* get pgd in ptr */ #endif #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT /* * For huge tlb entries, pmd doesn't contain an address but * instead contains the tlb pte. Check the PAGE_HUGE bit and * see if we need to jump to huge tlb processing. */ build_is_huge_pte(p, r, wr.r1, wr.r2, label_tlb_huge_update); #endif UASM_i_MFC0(p, wr.r1, C0_BADVADDR); UASM_i_LW(p, wr.r2, 0, wr.r2); UASM_i_SRL(p, wr.r1, wr.r1, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2); uasm_i_andi(p, wr.r1, wr.r1, (PTRS_PER_PTE - 1) << PTE_T_LOG2); UASM_i_ADDU(p, wr.r2, wr.r2, wr.r1); #ifdef CONFIG_SMP uasm_l_smp_pgtable_change(l, *p); #endif iPTE_LW(p, wr.r1, wr.r2); /* get even pte */ if (!m4kc_tlbp_war()) { build_tlb_probe_entry(p); if (cpu_has_tlbex_tlbp_race()) { /* race condition happens, leaving */ uasm_i_ehb(p); uasm_i_mfc0(p, wr.r3, C0_INDEX); uasm_il_bltz(p, r, wr.r3, label_leave); uasm_i_nop(p); } } return wr; } static void build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int tmp, unsigned int ptr) { uasm_i_ori(p, ptr, ptr, sizeof(pte_t)); uasm_i_xori(p, ptr, ptr, sizeof(pte_t)); build_update_entries(p, tmp, ptr); build_tlb_write_entry(p, l, r, tlb_indexed); uasm_l_leave(l, *p); build_restore_work_registers(p); uasm_i_eret(p); /* return from trap */ #ifdef CONFIG_64BIT build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill); #endif } static void build_r4000_tlb_load_handler(void) { u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl); struct uasm_label *l = labels; struct uasm_reloc *r = relocs; struct work_registers wr; memset(p, 0, handle_tlbl_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); if (bcm1250_m3_war()) { unsigned int segbits = 44; uasm_i_dmfc0(&p, K0, C0_BADVADDR); uasm_i_dmfc0(&p, K1, C0_ENTRYHI); uasm_i_xor(&p, K0, K0, K1); uasm_i_dsrl_safe(&p, K1, K0, 62); uasm_i_dsrl_safe(&p, K0, K0, 12 + 1); uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits); uasm_i_or(&p, K0, K0, K1); uasm_il_bnez(&p, &r, K0, label_leave); /* No need for uasm_i_nop */ } wr = build_r4000_tlbchange_handler_head(&p, &l, &r); build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl); if (m4kc_tlbp_war()) build_tlb_probe_entry(&p); if (cpu_has_rixi && !cpu_has_rixiex) { /* * If the page is not _PAGE_VALID, RI or XI could not * have triggered it. Skip the expensive test.. */ if (use_bbit_insns()) { uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID), label_tlbl_goaround1); } else { uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID); uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1); } uasm_i_nop(&p); /* * Warn if something may race with us & replace the TLB entry * before we read it here. Everything with such races should * also have dedicated RiXi exception handlers, so this * shouldn't be hit. */ WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path"); uasm_i_tlbr(&p); switch (current_cpu_type()) { default: if (cpu_has_mips_r2_exec_hazard) { uasm_i_ehb(&p); case CPU_CAVIUM_OCTEON: case CPU_CAVIUM_OCTEON_PLUS: case CPU_CAVIUM_OCTEON2: break; } } /* Examine entrylo 0 or 1 based on ptr. */ if (use_bbit_insns()) { uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8); } else { uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t)); uasm_i_beqz(&p, wr.r3, 8); } /* load it in the delay slot*/ UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0); /* load it if ptr is odd */ UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1); /* * If the entryLo (now in wr.r3) is valid (bit 1), RI or * XI must have triggered it. */ if (use_bbit_insns()) { uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl); uasm_i_nop(&p); uasm_l_tlbl_goaround1(&l, p); } else { uasm_i_andi(&p, wr.r3, wr.r3, 2); uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl); uasm_i_nop(&p); } uasm_l_tlbl_goaround1(&l, p); } build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3); build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT /* * This is the entry point when build_r4000_tlbchange_handler_head * spots a huge page. */ uasm_l_tlb_huge_update(&l, p); iPTE_LW(&p, wr.r1, wr.r2); build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl); build_tlb_probe_entry(&p); if (cpu_has_rixi && !cpu_has_rixiex) { /* * If the page is not _PAGE_VALID, RI or XI could not * have triggered it. Skip the expensive test.. */ if (use_bbit_insns()) { uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID), label_tlbl_goaround2); } else { uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID); uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2); } uasm_i_nop(&p); /* * Warn if something may race with us & replace the TLB entry * before we read it here. Everything with such races should * also have dedicated RiXi exception handlers, so this * shouldn't be hit. */ WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path"); uasm_i_tlbr(&p); switch (current_cpu_type()) { default: if (cpu_has_mips_r2_exec_hazard) { uasm_i_ehb(&p); case CPU_CAVIUM_OCTEON: case CPU_CAVIUM_OCTEON_PLUS: case CPU_CAVIUM_OCTEON2: break; } } /* Examine entrylo 0 or 1 based on ptr. */ if (use_bbit_insns()) { uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8); } else { uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t)); uasm_i_beqz(&p, wr.r3, 8); } /* load it in the delay slot*/ UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0); /* load it if ptr is odd */ UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1); /* * If the entryLo (now in wr.r3) is valid (bit 1), RI or * XI must have triggered it. */ if (use_bbit_insns()) { uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2); } else { uasm_i_andi(&p, wr.r3, wr.r3, 2); uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2); } if (PM_DEFAULT_MASK == 0) uasm_i_nop(&p); /* * We clobbered C0_PAGEMASK, restore it. On the other branch * it is restored in build_huge_tlb_write_entry. */ build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0); uasm_l_tlbl_goaround2(&l, p); } uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID)); build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); #endif uasm_l_nopage_tlbl(&l, p); if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) uasm_i_sync(&p, 0); build_restore_work_registers(&p); #ifdef CONFIG_CPU_MICROMIPS if ((unsigned long)tlb_do_page_fault_0 & 1) { uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0)); uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0)); uasm_i_jr(&p, K0); } else #endif uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff); uasm_i_nop(&p); if (p >= (u32 *)handle_tlbl_end) panic("TLB load handler fastpath space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB load handler fastpath (%u instructions).\n", (unsigned int)(p - (u32 *)handle_tlbl)); dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_end); } static void build_r4000_tlb_store_handler(void) { u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbs); struct uasm_label *l = labels; struct uasm_reloc *r = relocs; struct work_registers wr; memset(p, 0, handle_tlbs_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); wr = build_r4000_tlbchange_handler_head(&p, &l, &r); build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs); if (m4kc_tlbp_war()) build_tlb_probe_entry(&p); build_make_write(&p, &r, wr.r1, wr.r2, wr.r3); build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT /* * This is the entry point when * build_r4000_tlbchange_handler_head spots a huge page. */ uasm_l_tlb_huge_update(&l, p); iPTE_LW(&p, wr.r1, wr.r2); build_pte_writable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbs); build_tlb_probe_entry(&p); uasm_i_ori(&p, wr.r1, wr.r1, _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); #endif uasm_l_nopage_tlbs(&l, p); if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) uasm_i_sync(&p, 0); build_restore_work_registers(&p); #ifdef CONFIG_CPU_MICROMIPS if ((unsigned long)tlb_do_page_fault_1 & 1) { uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1)); uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1)); uasm_i_jr(&p, K0); } else #endif uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff); uasm_i_nop(&p); if (p >= (u32 *)handle_tlbs_end) panic("TLB store handler fastpath space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB store handler fastpath (%u instructions).\n", (unsigned int)(p - (u32 *)handle_tlbs)); dump_handler("r4000_tlb_store", handle_tlbs, handle_tlbs_end); } static void build_r4000_tlb_modify_handler(void) { u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbm); struct uasm_label *l = labels; struct uasm_reloc *r = relocs; struct work_registers wr; memset(p, 0, handle_tlbm_end - (char *)p); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); wr = build_r4000_tlbchange_handler_head(&p, &l, &r); build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm); if (m4kc_tlbp_war()) build_tlb_probe_entry(&p); /* Present and writable bits set, set accessed and dirty bits. */ build_make_write(&p, &r, wr.r1, wr.r2, wr.r3); build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT /* * This is the entry point when * build_r4000_tlbchange_handler_head spots a huge page. */ uasm_l_tlb_huge_update(&l, p); iPTE_LW(&p, wr.r1, wr.r2); build_pte_modifiable(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbm); build_tlb_probe_entry(&p); uasm_i_ori(&p, wr.r1, wr.r1, _PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0); #endif uasm_l_nopage_tlbm(&l, p); if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) uasm_i_sync(&p, 0); build_restore_work_registers(&p); #ifdef CONFIG_CPU_MICROMIPS if ((unsigned long)tlb_do_page_fault_1 & 1) { uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1)); uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1)); uasm_i_jr(&p, K0); } else #endif uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff); uasm_i_nop(&p); if (p >= (u32 *)handle_tlbm_end) panic("TLB modify handler fastpath space exceeded"); uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB modify handler fastpath (%u instructions).\n", (unsigned int)(p - (u32 *)handle_tlbm)); dump_handler("r4000_tlb_modify", handle_tlbm, handle_tlbm_end); } static void flush_tlb_handlers(void) { local_flush_icache_range((unsigned long)handle_tlbl, (unsigned long)handle_tlbl_end); local_flush_icache_range((unsigned long)handle_tlbs, (unsigned long)handle_tlbs_end); local_flush_icache_range((unsigned long)handle_tlbm, (unsigned long)handle_tlbm_end); local_flush_icache_range((unsigned long)tlbmiss_handler_setup_pgd, (unsigned long)tlbmiss_handler_setup_pgd_end); } static void print_htw_config(void) { unsigned long config; unsigned int pwctl; const int field = 2 * sizeof(unsigned long); config = read_c0_pwfield(); pr_debug("PWField (0x%0*lx): GDI: 0x%02lx UDI: 0x%02lx MDI: 0x%02lx PTI: 0x%02lx PTEI: 0x%02lx\n", field, config, (config & MIPS_PWFIELD_GDI_MASK) >> MIPS_PWFIELD_GDI_SHIFT, (config & MIPS_PWFIELD_UDI_MASK) >> MIPS_PWFIELD_UDI_SHIFT, (config & MIPS_PWFIELD_MDI_MASK) >> MIPS_PWFIELD_MDI_SHIFT, (config & MIPS_PWFIELD_PTI_MASK) >> MIPS_PWFIELD_PTI_SHIFT, (config & MIPS_PWFIELD_PTEI_MASK) >> MIPS_PWFIELD_PTEI_SHIFT); config = read_c0_pwsize(); 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", field, config, (config & MIPS_PWSIZE_PS_MASK) >> MIPS_PWSIZE_PS_SHIFT, (config & MIPS_PWSIZE_GDW_MASK) >> MIPS_PWSIZE_GDW_SHIFT, (config & MIPS_PWSIZE_UDW_MASK) >> MIPS_PWSIZE_UDW_SHIFT, (config & MIPS_PWSIZE_MDW_MASK) >> MIPS_PWSIZE_MDW_SHIFT, (config & MIPS_PWSIZE_PTW_MASK) >> MIPS_PWSIZE_PTW_SHIFT, (config & MIPS_PWSIZE_PTEW_MASK) >> MIPS_PWSIZE_PTEW_SHIFT); pwctl = read_c0_pwctl(); 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", pwctl, (pwctl & MIPS_PWCTL_PWEN_MASK) >> MIPS_PWCTL_PWEN_SHIFT, (pwctl & MIPS_PWCTL_XK_MASK) >> MIPS_PWCTL_XK_SHIFT, (pwctl & MIPS_PWCTL_XS_MASK) >> MIPS_PWCTL_XS_SHIFT, (pwctl & MIPS_PWCTL_XU_MASK) >> MIPS_PWCTL_XU_SHIFT, (pwctl & MIPS_PWCTL_DPH_MASK) >> MIPS_PWCTL_DPH_SHIFT, (pwctl & MIPS_PWCTL_HUGEPG_MASK) >> MIPS_PWCTL_HUGEPG_SHIFT, (pwctl & MIPS_PWCTL_PSN_MASK) >> MIPS_PWCTL_PSN_SHIFT); } static void config_htw_params(void) { unsigned long pwfield, pwsize, ptei; unsigned int config; /* * We are using 2-level page tables, so we only need to * setup GDW and PTW appropriately. UDW and MDW will remain 0. * The default value of GDI/UDI/MDI/PTI is 0xc. It is illegal to * write values less than 0xc in these fields because the entire * write will be dropped. As a result of which, we must preserve * the original reset values and overwrite only what we really want. */ pwfield = read_c0_pwfield(); /* re-initialize the GDI field */ pwfield &= ~MIPS_PWFIELD_GDI_MASK; pwfield |= PGDIR_SHIFT << MIPS_PWFIELD_GDI_SHIFT; /* re-initialize the PTI field including the even/odd bit */ pwfield &= ~MIPS_PWFIELD_PTI_MASK; pwfield |= PAGE_SHIFT << MIPS_PWFIELD_PTI_SHIFT; if (CONFIG_PGTABLE_LEVELS >= 3) { pwfield &= ~MIPS_PWFIELD_MDI_MASK; pwfield |= PMD_SHIFT << MIPS_PWFIELD_MDI_SHIFT; } /* Set the PTEI right shift */ ptei = _PAGE_GLOBAL_SHIFT << MIPS_PWFIELD_PTEI_SHIFT; pwfield |= ptei; write_c0_pwfield(pwfield); /* Check whether the PTEI value is supported */ back_to_back_c0_hazard(); pwfield = read_c0_pwfield(); if (((pwfield & MIPS_PWFIELD_PTEI_MASK) << MIPS_PWFIELD_PTEI_SHIFT) != ptei) { pr_warn("Unsupported PTEI field value: 0x%lx. HTW will not be enabled", ptei); /* * Drop option to avoid HTW being enabled via another path * (eg htw_reset()) */ current_cpu_data.options &= ~MIPS_CPU_HTW; return; } pwsize = ilog2(PTRS_PER_PGD) << MIPS_PWSIZE_GDW_SHIFT; pwsize |= ilog2(PTRS_PER_PTE) << MIPS_PWSIZE_PTW_SHIFT; if (CONFIG_PGTABLE_LEVELS >= 3) pwsize |= ilog2(PTRS_PER_PMD) << MIPS_PWSIZE_MDW_SHIFT; /* Set pointer size to size of directory pointers */ if (IS_ENABLED(CONFIG_64BIT)) pwsize |= MIPS_PWSIZE_PS_MASK; /* PTEs may be multiple pointers long (e.g. with XPA) */ pwsize |= ((PTE_T_LOG2 - PGD_T_LOG2) << MIPS_PWSIZE_PTEW_SHIFT) & MIPS_PWSIZE_PTEW_MASK; write_c0_pwsize(pwsize); /* Make sure everything is set before we enable the HTW */ back_to_back_c0_hazard(); /* * Enable HTW (and only for XUSeg on 64-bit), and disable the rest of * the pwctl fields. */ config = 1 << MIPS_PWCTL_PWEN_SHIFT; if (IS_ENABLED(CONFIG_64BIT)) config |= MIPS_PWCTL_XU_MASK; write_c0_pwctl(config); pr_info("Hardware Page Table Walker enabled\n"); print_htw_config(); } static void config_xpa_params(void) { #ifdef CONFIG_XPA unsigned int pagegrain; if (mips_xpa_disabled) { pr_info("Extended Physical Addressing (XPA) disabled\n"); return; } pagegrain = read_c0_pagegrain(); write_c0_pagegrain(pagegrain | PG_ELPA); back_to_back_c0_hazard(); pagegrain = read_c0_pagegrain(); if (pagegrain & PG_ELPA) pr_info("Extended Physical Addressing (XPA) enabled\n"); else panic("Extended Physical Addressing (XPA) disabled"); #endif } static void check_pabits(void) { unsigned long entry; unsigned pabits, fillbits; if (!cpu_has_rixi || _PAGE_NO_EXEC == 0) { /* * We'll only be making use of the fact that we can rotate bits * into the fill if the CPU supports RIXI, so don't bother * probing this for CPUs which don't. */ return; } write_c0_entrylo0(~0ul); back_to_back_c0_hazard(); entry = read_c0_entrylo0(); /* clear all non-PFN bits */ entry &= ~((1 << MIPS_ENTRYLO_PFN_SHIFT) - 1); entry &= ~(MIPS_ENTRYLO_RI | MIPS_ENTRYLO_XI); /* find a lower bound on PABITS, and upper bound on fill bits */ pabits = fls_long(entry) + 6; fillbits = max_t(int, (int)BITS_PER_LONG - pabits, 0); /* minus the RI & XI bits */ fillbits -= min_t(unsigned, fillbits, 2); if (fillbits >= ilog2(_PAGE_NO_EXEC)) fill_includes_sw_bits = true; pr_debug("Entry* registers contain %u fill bits\n", fillbits); } void build_tlb_refill_handler(void) { /* * The refill handler is generated per-CPU, multi-node systems * may have local storage for it. The other handlers are only * needed once. */ static int run_once = 0; if (IS_ENABLED(CONFIG_XPA) && !cpu_has_rixi) panic("Kernels supporting XPA currently require CPUs with RIXI"); output_pgtable_bits_defines(); check_pabits(); #ifdef CONFIG_64BIT check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3); #endif if (cpu_has_3kex) { #ifndef CONFIG_MIPS_PGD_C0_CONTEXT if (!run_once) { build_setup_pgd(); build_r3000_tlb_refill_handler(); build_r3000_tlb_load_handler(); build_r3000_tlb_store_handler(); build_r3000_tlb_modify_handler(); flush_tlb_handlers(); run_once++; } #else panic("No R3000 TLB refill handler"); #endif return; } if (cpu_has_ldpte) setup_pw(); if (!run_once) { scratch_reg = allocate_kscratch(); build_setup_pgd(); build_r4000_tlb_load_handler(); build_r4000_tlb_store_handler(); build_r4000_tlb_modify_handler(); if (cpu_has_ldpte) build_loongson3_tlb_refill_handler(); else build_r4000_tlb_refill_handler(); flush_tlb_handlers(); run_once++; } if (cpu_has_xpa) config_xpa_params(); if (cpu_has_htw) config_htw_params(); }