/* * 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) * * ... and the days got worse and worse and now you see * I've gone completly 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 "uasm.h" 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; } static inline int __maybe_unused bcm1250_m3_war(void) { return BCM1250_M3_WAR; } static inline int __maybe_unused r10000_llsc_war(void) { return R10000_LLSC_WAR; } /* * 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 __cpuinit m4kc_tlbp_war(void) { return (current_cpu_data.processor_id & 0xffff00) == (PRID_COMP_MIPS | PRID_IMP_4KC); } /* Handle labels (which must be positive integers). */ enum label_id { label_second_part = 1, label_leave, #ifdef MODULE_START label_module_alloc, #endif label_vmalloc, label_vmalloc_done, label_tlbw_hazard, label_split, label_nopage_tlbl, label_nopage_tlbs, label_nopage_tlbm, label_smp_pgtable_change, label_r3000_write_probe_fail, }; UASM_L_LA(_second_part) UASM_L_LA(_leave) #ifdef MODULE_START UASM_L_LA(_module_alloc) #endif UASM_L_LA(_vmalloc) UASM_L_LA(_vmalloc_done) UASM_L_LA(_tlbw_hazard) UASM_L_LA(_split) 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) /* * For debug purposes. */ static inline void dump_handler(const u32 *handler, int count) { int i; pr_debug("\t.set push\n"); pr_debug("\t.set noreorder\n"); for (i = 0; i < count; i++) pr_debug("\t%p\t.word 0x%08x\n", &handler[i], handler[i]); pr_debug("\t.set pop\n"); } /* 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_BADVADDR 8, 0 #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] __cpuinitdata; /* simply assume worst case size for labels and relocs */ static struct uasm_label labels[128] __cpuinitdata; static struct uasm_reloc relocs[128] __cpuinitdata; /* * The R3000 TLB handler is simple. */ static void __cpuinit 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); dump_handler((u32 *)ebase, 32); } /* * 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] __cpuinitdata; /* * 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 __cpuinit __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_R5000A: case CPU_NEVADA: uasm_i_nop(p); uasm_i_tlbp(p); break; default: uasm_i_tlbp(p); break; } } /* * Write random or indexed TLB entry, and care about the hazards from * the preceeding mtc0 and for the following eret. */ enum tlb_write_entry { tlb_random, tlb_indexed }; static void __cpuinit 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) { 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_il_bgezl(p, r, 0, label_tlbw_hazard); tlbw(p); uasm_l_tlbw_hazard(l, *p); uasm_i_nop(p); break; case CPU_R4600: case CPU_R4700: case CPU_R5000: case CPU_R5000A: uasm_i_nop(p); tlbw(p); uasm_i_nop(p); break; case CPU_R4300: case CPU_5KC: case CPU_TX49XX: case CPU_PR4450: uasm_i_nop(p); tlbw(p); break; case CPU_R10000: case CPU_R12000: case CPU_R14000: case CPU_4KC: case CPU_4KEC: case CPU_SB1: case CPU_SB1A: case CPU_4KSC: case CPU_20KC: case CPU_25KF: case CPU_BCM3302: case CPU_BCM4710: case CPU_LOONGSON2: case CPU_CAVIUM_OCTEON: case CPU_R5500: if (m4kc_tlbp_war()) uasm_i_nop(p); case CPU_ALCHEMY: tlbw(p); break; case CPU_NEVADA: uasm_i_nop(p); /* QED specifies 2 nops hazard */ /* * This branch uses up a mtc0 hazard nop slot and saves * a nop after the tlbw instruction. */ uasm_il_bgezl(p, r, 0, label_tlbw_hazard); tlbw(p); uasm_l_tlbw_hazard(l, *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_RM9000: /* * When the JTLB is updated by tlbwi or tlbwr, a subsequent * use of the JTLB for instructions should not occur for 4 * cpu cycles and use for data translations should not occur * for 3 cpu cycles. */ uasm_i_ssnop(p); uasm_i_ssnop(p); uasm_i_ssnop(p); uasm_i_ssnop(p); tlbw(p); uasm_i_ssnop(p); uasm_i_ssnop(p); uasm_i_ssnop(p); uasm_i_ssnop(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: case CPU_R5432: uasm_i_nop(p); uasm_i_nop(p); tlbw(p); break; default: panic("No TLB refill handler yet (CPU type: %d)", current_cpu_data.cputype); break; } } #ifdef CONFIG_64BIT /* * TMP and PTR are scratch. * TMP will be clobbered, PTR will hold the pmd entry. */ static void __cpuinit build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int tmp, unsigned int ptr) { long pgdc = (long)pgd_current; /* * The vmalloc handling is not in the hotpath. */ uasm_i_dmfc0(p, tmp, C0_BADVADDR); #ifdef MODULE_START uasm_il_bltz(p, r, tmp, label_module_alloc); #else uasm_il_bltz(p, r, tmp, label_vmalloc); #endif /* No uasm_i_nop needed here, since the next insn doesn't touch TMP. */ #ifdef CONFIG_SMP # ifdef CONFIG_MIPS_MT_SMTC /* * SMTC uses TCBind value as "CPU" index */ uasm_i_mfc0(p, ptr, C0_TCBIND); uasm_i_dsrl(p, ptr, ptr, 19); # else /* * 64 bit SMP running in XKPHYS has smp_processor_id() << 3 * stored in CONTEXT. */ uasm_i_dmfc0(p, ptr, C0_CONTEXT); uasm_i_dsrl(p, ptr, ptr, 23); #endif 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); if (PGDIR_SHIFT - 3 < 32) /* get pgd offset in bytes */ uasm_i_dsrl(p, tmp, tmp, PGDIR_SHIFT-3); else uasm_i_dsrl32(p, tmp, tmp, PGDIR_SHIFT - 3 - 32); uasm_i_andi(p, tmp, tmp, (PTRS_PER_PGD - 1)<<3); uasm_i_daddu(p, ptr, ptr, tmp); /* add in pgd offset */ uasm_i_dmfc0(p, tmp, C0_BADVADDR); /* get faulting address */ uasm_i_ld(p, ptr, 0, ptr); /* get pmd pointer */ uasm_i_dsrl(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 */ } /* * BVADDR is the faulting address, PTR is scratch. * PTR will hold the pgd for vmalloc. */ static void __cpuinit build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int bvaddr, unsigned int ptr) { long swpd = (long)swapper_pg_dir; #ifdef MODULE_START long modd = (long)module_pg_dir; uasm_l_module_alloc(l, *p); /* * Assumption: * VMALLOC_START >= 0xc000000000000000UL * MODULE_START >= 0xe000000000000000UL */ UASM_i_SLL(p, ptr, bvaddr, 2); uasm_il_bgez(p, r, ptr, label_vmalloc); if (uasm_in_compat_space_p(MODULE_START) && !uasm_rel_lo(MODULE_START)) { uasm_i_lui(p, ptr, uasm_rel_hi(MODULE_START)); /* delay slot */ } else { /* unlikely configuration */ uasm_i_nop(p); /* delay slot */ UASM_i_LA(p, ptr, MODULE_START); } uasm_i_dsubu(p, bvaddr, bvaddr, ptr); if (uasm_in_compat_space_p(modd) && !uasm_rel_lo(modd)) { uasm_il_b(p, r, label_vmalloc_done); uasm_i_lui(p, ptr, uasm_rel_hi(modd)); } else { UASM_i_LA_mostly(p, ptr, modd); uasm_il_b(p, r, label_vmalloc_done); if (uasm_in_compat_space_p(modd)) uasm_i_addiu(p, ptr, ptr, uasm_rel_lo(modd)); else uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(modd)); } uasm_l_vmalloc(l, *p); if (uasm_in_compat_space_p(MODULE_START) && !uasm_rel_lo(MODULE_START) && MODULE_START << 32 == VMALLOC_START) uasm_i_dsll32(p, ptr, ptr, 0); /* typical case */ else UASM_i_LA(p, ptr, VMALLOC_START); #else uasm_l_vmalloc(l, *p); UASM_i_LA(p, ptr, VMALLOC_START); #endif uasm_i_dsubu(p, bvaddr, bvaddr, ptr); if (uasm_in_compat_space_p(swpd) && !uasm_rel_lo(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)); } } #else /* !CONFIG_64BIT */ /* * TMP and PTR are scratch. * TMP will be clobbered, PTR will hold the pgd entry. */ static void __cpuinit __maybe_unused build_get_pgde32(u32 **p, unsigned int tmp, unsigned int ptr) { long pgdc = (long)pgd_current; /* 32 bit SMP has smp_processor_id() stored in CONTEXT. */ #ifdef CONFIG_SMP #ifdef CONFIG_MIPS_MT_SMTC /* * SMTC uses TCBind value as "CPU" index */ uasm_i_mfc0(p, ptr, C0_TCBIND); UASM_i_LA_mostly(p, tmp, pgdc); uasm_i_srl(p, ptr, ptr, 19); #else /* * smp_processor_id() << 3 is stored in CONTEXT. */ uasm_i_mfc0(p, ptr, C0_CONTEXT); UASM_i_LA_mostly(p, tmp, pgdc); uasm_i_srl(p, ptr, ptr, 23); #endif 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 */ } #endif /* !CONFIG_64BIT */ static void __cpuinit 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); } static void __cpuinit 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 */ } static void __cpuinit build_update_entries(u32 **p, unsigned int tmp, unsigned int ptep) { /* * 64bit address support (36bit on a 32bit CPU) in a 32bit * Kernel is a special case. Only a few CPUs use it. */ #ifdef CONFIG_64BIT_PHYS_ADDR if (cpu_has_64bits) { uasm_i_ld(p, tmp, 0, ptep); /* get even pte */ uasm_i_ld(p, ptep, sizeof(pte_t), ptep); /* get odd pte */ uasm_i_dsrl(p, tmp, tmp, 6); /* convert to entrylo0 */ uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */ uasm_i_dsrl(p, ptep, ptep, 6); /* convert to entrylo1 */ uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */ } else { int pte_off_even = sizeof(pte_t) / 2; int pte_off_odd = pte_off_even + sizeof(pte_t); /* The pte entries are pre-shifted */ uasm_i_lw(p, tmp, pte_off_even, ptep); /* get even pte */ uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */ uasm_i_lw(p, ptep, pte_off_odd, ptep); /* get odd pte */ uasm_i_mtc0(p, ptep, C0_ENTRYLO1); /* load it */ } #else UASM_i_LW(p, tmp, 0, ptep); /* get even pte */ UASM_i_LW(p, ptep, sizeof(pte_t), ptep); /* get odd pte */ if (r45k_bvahwbug()) build_tlb_probe_entry(p); UASM_i_SRL(p, tmp, tmp, 6); /* convert to entrylo0 */ if (r4k_250MHZhwbug()) uasm_i_mtc0(p, 0, C0_ENTRYLO0); uasm_i_mtc0(p, tmp, C0_ENTRYLO0); /* load it */ UASM_i_SRL(p, ptep, ptep, 6); /* convert to entrylo1 */ 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 */ #endif } /* * 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 __cpuinit 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; memset(tlb_handler, 0, sizeof(tlb_handler)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); memset(final_handler, 0, sizeof(final_handler)); /* * create the plain linear handler */ if (bcm1250_m3_war()) { UASM_i_MFC0(&p, K0, C0_BADVADDR); UASM_i_MFC0(&p, K1, C0_ENTRYHI); uasm_i_xor(&p, K0, K0, K1); UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1); 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 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_64BIT build_get_pgd_vmalloc64(&p, &l, &r, K0, K1); #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. */ /* Loongson2 ebase is different than r4k, we have more space */ #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2) if ((p - tlb_handler) > 64) panic("TLB refill handler space exceeded"); #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"); #endif /* * Now fold the handler in the TLB refill handler space. */ #if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2) f = final_handler; /* Simplest case, just copy the handler. */ uasm_copy_handler(relocs, labels, tlb_handler, p, f); final_len = p - tlb_handler; #else /* CONFIG_64BIT */ 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 MODULE_START const enum label_id ls = label_module_alloc; #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); } #endif /* CONFIG_64BIT */ uasm_resolve_relocs(relocs, labels); pr_debug("Wrote TLB refill handler (%u instructions).\n", final_len); memcpy((void *)ebase, final_handler, 0x100); dump_handler((u32 *)ebase, 64); } /* * 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); /* * 128 instructions for the fastpath handler is generous and should * never be exceeded. */ #define FASTPATH_SIZE 128 u32 handle_tlbl[FASTPATH_SIZE] __cacheline_aligned; u32 handle_tlbs[FASTPATH_SIZE] __cacheline_aligned; u32 handle_tlbm[FASTPATH_SIZE] __cacheline_aligned; static void __cpuinit iPTE_LW(u32 **p, struct uasm_label **l, unsigned int pte, unsigned int ptr) { #ifdef CONFIG_SMP # ifdef CONFIG_64BIT_PHYS_ADDR if (cpu_has_64bits) uasm_i_lld(p, pte, 0, ptr); else # endif UASM_i_LL(p, pte, 0, ptr); #else # ifdef CONFIG_64BIT_PHYS_ADDR if (cpu_has_64bits) uasm_i_ld(p, pte, 0, ptr); else # endif UASM_i_LW(p, pte, 0, ptr); #endif } static void __cpuinit iPTE_SW(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, unsigned int mode) { #ifdef CONFIG_64BIT_PHYS_ADDR unsigned int hwmode = mode & (_PAGE_VALID | _PAGE_DIRTY); #endif uasm_i_ori(p, pte, pte, mode); #ifdef CONFIG_SMP # ifdef CONFIG_64BIT_PHYS_ADDR 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_64BIT_PHYS_ADDR 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); 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_64BIT_PHYS_ADDR if (cpu_has_64bits) uasm_i_sd(p, pte, 0, ptr); else # endif UASM_i_SW(p, pte, 0, ptr); # ifdef CONFIG_64BIT_PHYS_ADDR if (!cpu_has_64bits) { uasm_i_lw(p, pte, sizeof(pte_t) / 2, ptr); uasm_i_ori(p, pte, pte, hwmode); 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 __cpuinit build_pte_present(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, enum label_id lid) { uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_READ); uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_READ); uasm_il_bnez(p, r, pte, lid); iPTE_LW(p, l, pte, ptr); } /* Make PTE valid, store result in PTR. */ static void __cpuinit build_make_valid(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr) { unsigned int mode = _PAGE_VALID | _PAGE_ACCESSED; iPTE_SW(p, r, pte, ptr, mode); } /* * Check if PTE can be written to, if not branch to LABEL. Regardless * restore PTE with value from PTR when done. */ static void __cpuinit build_pte_writable(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, enum label_id lid) { uasm_i_andi(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE); uasm_i_xori(p, pte, pte, _PAGE_PRESENT | _PAGE_WRITE); uasm_il_bnez(p, r, pte, lid); iPTE_LW(p, l, pte, ptr); } /* Make PTE writable, update software status bits as well, then store * at PTR. */ static void __cpuinit build_make_write(u32 **p, struct uasm_reloc **r, unsigned int pte, unsigned int ptr) { unsigned int mode = (_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY); iPTE_SW(p, r, pte, ptr, mode); } /* * Check if PTE can be modified, if not branch to LABEL. Regardless * restore PTE with value from PTR when done. */ static void __cpuinit build_pte_modifiable(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int pte, unsigned int ptr, enum label_id lid) { uasm_i_andi(p, pte, pte, _PAGE_WRITE); uasm_il_beqz(p, r, pte, lid); iPTE_LW(p, l, pte, ptr); } /* * R3000 style TLB load/store/modify handlers. */ /* * This places the pte into ENTRYLO0 and writes it with tlbwi. * Then it returns. */ static void __cpuinit 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 __cpuinit 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 __cpuinit 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 __cpuinit build_r3000_tlb_load_handler(void) { u32 *p = handle_tlbl; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(handle_tlbl, 0, sizeof(handle_tlbl)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r3000_tlbchange_handler_head(&p, K0, K1); build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl); uasm_i_nop(&p); /* load delay */ build_make_valid(&p, &r, K0, K1); 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 - handle_tlbl) > FASTPATH_SIZE) 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 - handle_tlbl)); dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl)); } static void __cpuinit build_r3000_tlb_store_handler(void) { u32 *p = handle_tlbs; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(handle_tlbs, 0, sizeof(handle_tlbs)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r3000_tlbchange_handler_head(&p, K0, K1); build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs); uasm_i_nop(&p); /* load delay */ build_make_write(&p, &r, K0, K1); 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 - handle_tlbs) > FASTPATH_SIZE) 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 - handle_tlbs)); dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs)); } static void __cpuinit build_r3000_tlb_modify_handler(void) { u32 *p = handle_tlbm; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(handle_tlbm, 0, sizeof(handle_tlbm)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r3000_tlbchange_handler_head(&p, K0, K1); build_pte_modifiable(&p, &l, &r, K0, K1, label_nopage_tlbm); uasm_i_nop(&p); /* load delay */ build_make_write(&p, &r, K0, K1); 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 - handle_tlbm) > FASTPATH_SIZE) 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 - handle_tlbm)); dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm)); } /* * R4000 style TLB load/store/modify handlers. */ static void __cpuinit build_r4000_tlbchange_handler_head(u32 **p, struct uasm_label **l, struct uasm_reloc **r, unsigned int pte, unsigned int ptr) { #ifdef CONFIG_64BIT build_get_pmde64(p, l, r, pte, ptr); /* get pmd in ptr */ #else build_get_pgde32(p, pte, ptr); /* get pgd in ptr */ #endif UASM_i_MFC0(p, pte, C0_BADVADDR); UASM_i_LW(p, ptr, 0, ptr); UASM_i_SRL(p, pte, pte, PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2); uasm_i_andi(p, pte, pte, (PTRS_PER_PTE - 1) << PTE_T_LOG2); UASM_i_ADDU(p, ptr, ptr, pte); #ifdef CONFIG_SMP uasm_l_smp_pgtable_change(l, *p); #endif iPTE_LW(p, l, pte, ptr); /* get even pte */ if (!m4kc_tlbp_war()) build_tlb_probe_entry(p); } static void __cpuinit 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); uasm_i_eret(p); /* return from trap */ #ifdef CONFIG_64BIT build_get_pgd_vmalloc64(p, l, r, tmp, ptr); #endif } static void __cpuinit build_r4000_tlb_load_handler(void) { u32 *p = handle_tlbl; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(handle_tlbl, 0, sizeof(handle_tlbl)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); if (bcm1250_m3_war()) { UASM_i_MFC0(&p, K0, C0_BADVADDR); UASM_i_MFC0(&p, K1, C0_ENTRYHI); uasm_i_xor(&p, K0, K0, K1); UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1); uasm_il_bnez(&p, &r, K0, label_leave); /* No need for uasm_i_nop */ } build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1); build_pte_present(&p, &l, &r, K0, K1, label_nopage_tlbl); if (m4kc_tlbp_war()) build_tlb_probe_entry(&p); build_make_valid(&p, &r, K0, K1); build_r4000_tlbchange_handler_tail(&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 - handle_tlbl) > FASTPATH_SIZE) 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 - handle_tlbl)); dump_handler(handle_tlbl, ARRAY_SIZE(handle_tlbl)); } static void __cpuinit build_r4000_tlb_store_handler(void) { u32 *p = handle_tlbs; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(handle_tlbs, 0, sizeof(handle_tlbs)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1); build_pte_writable(&p, &l, &r, K0, K1, label_nopage_tlbs); if (m4kc_tlbp_war()) build_tlb_probe_entry(&p); build_make_write(&p, &r, K0, K1); build_r4000_tlbchange_handler_tail(&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 - handle_tlbs) > FASTPATH_SIZE) 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 - handle_tlbs)); dump_handler(handle_tlbs, ARRAY_SIZE(handle_tlbs)); } static void __cpuinit build_r4000_tlb_modify_handler(void) { u32 *p = handle_tlbm; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; memset(handle_tlbm, 0, sizeof(handle_tlbm)); memset(labels, 0, sizeof(labels)); memset(relocs, 0, sizeof(relocs)); build_r4000_tlbchange_handler_head(&p, &l, &r, K0, K1); build_pte_modifiable(&p, &l, &r, K0, K1, 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, K0, K1); build_r4000_tlbchange_handler_tail(&p, &l, &r, 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 - handle_tlbm) > FASTPATH_SIZE) 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 - handle_tlbm)); dump_handler(handle_tlbm, ARRAY_SIZE(handle_tlbm)); } void __cpuinit 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; switch (current_cpu_type()) { case CPU_R2000: case CPU_R3000: case CPU_R3000A: case CPU_R3081E: case CPU_TX3912: case CPU_TX3922: case CPU_TX3927: build_r3000_tlb_refill_handler(); if (!run_once) { build_r3000_tlb_load_handler(); build_r3000_tlb_store_handler(); build_r3000_tlb_modify_handler(); run_once++; } break; case CPU_R6000: case CPU_R6000A: panic("No R6000 TLB refill handler yet"); break; case CPU_R8000: panic("No R8000 TLB refill handler yet"); break; default: build_r4000_tlb_refill_handler(); if (!run_once) { build_r4000_tlb_load_handler(); build_r4000_tlb_store_handler(); build_r4000_tlb_modify_handler(); run_once++; } } } void __cpuinit flush_tlb_handlers(void) { local_flush_icache_range((unsigned long)handle_tlbl, (unsigned long)handle_tlbl + sizeof(handle_tlbl)); local_flush_icache_range((unsigned long)handle_tlbs, (unsigned long)handle_tlbs + sizeof(handle_tlbs)); local_flush_icache_range((unsigned long)handle_tlbm, (unsigned long)handle_tlbm + sizeof(handle_tlbm)); }