diff options
Diffstat (limited to 'arch/mips/mm/tlbex.c')
-rw-r--r-- | arch/mips/mm/tlbex.c | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index e7149290d1cb..6c425b052442 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -58,6 +58,21 @@ static __init int __maybe_unused r10000_llsc_war(void) } /* + * 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 __init int __attribute__((unused)) m4kc_tlbp_war(void) +{ + return (current_cpu_data.processor_id & 0xffff00) == + (PRID_COMP_MIPS | PRID_IMP_4KC); +} + +/* * A little micro-assembler, intended for TLB refill handler * synthesizing. It is intentionally kept simple, does only support * a subset of instructions, and does not try to hide pipeline effects @@ -78,7 +93,7 @@ enum fields SET = 0x200 }; -#define OP_MASK 0x2f +#define OP_MASK 0x3f #define OP_SH 26 #define RS_MASK 0x1f #define RS_SH 21 @@ -92,7 +107,7 @@ enum fields #define IMM_SH 0 #define JIMM_MASK 0x3ffffff #define JIMM_SH 0 -#define FUNC_MASK 0x2f +#define FUNC_MASK 0x3f #define FUNC_SH 0 #define SET_MASK 0x7 #define SET_SH 0 @@ -893,6 +908,9 @@ static __init void build_tlb_write_entry(u32 **p, struct label **l, case CPU_4KSC: case CPU_20KC: case CPU_25KF: + case CPU_LOONGSON2: + if (m4kc_tlbp_war()) + i_nop(p); tlbw(p); break; @@ -1276,7 +1294,8 @@ static void __init build_r4000_tlb_refill_handler(void) * need three, with the second nop'ed and the third being * unused. */ -#ifdef CONFIG_32BIT + /* 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 @@ -1289,7 +1308,7 @@ static void __init build_r4000_tlb_refill_handler(void) /* * Now fold the handler in the TLB refill handler space. */ -#ifdef CONFIG_32BIT +#if defined(CONFIG_32BIT) || defined(CONFIG_CPU_LOONGSON2) f = final_handler; /* Simplest case, just copy the handler. */ copy_handler(relocs, labels, tlb_handler, p, f); @@ -1336,7 +1355,7 @@ static void __init build_r4000_tlb_refill_handler(void) final_len); f = final_handler; -#ifdef CONFIG_64BIT +#if defined(CONFIG_64BIT) && !defined(CONFIG_CPU_LOONGSON2) if (final_len > 32) final_len = 64; else @@ -1703,7 +1722,8 @@ build_r4000_tlbchange_handler_head(u32 **p, struct label **l, l_smp_pgtable_change(l, *p); # endif iPTE_LW(p, l, pte, ptr); /* get even pte */ - build_tlb_probe_entry(p); + if (!m4kc_tlbp_war()) + build_tlb_probe_entry(p); } static void __init @@ -1745,6 +1765,8 @@ static void __init build_r4000_tlb_load_handler(void) 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); @@ -1779,6 +1801,8 @@ static void __init build_r4000_tlb_store_handler(void) 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); @@ -1813,6 +1837,8 @@ static void __init build_r4000_tlb_modify_handler(void) 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); |