diff options
Diffstat (limited to 'arch/mips/mm')
| -rw-r--r-- | arch/mips/mm/tlbex.c | 110 |
1 files changed, 87 insertions, 23 deletions
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index 61374b2c930..86f004dc835 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -31,6 +31,16 @@ #include <asm/war.h> #include <asm/uasm.h> +/* + * 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); + + static inline int r45k_bvahwbug(void) { /* XXX: We should probe for the presence of this bug, but we don't. */ @@ -83,6 +93,7 @@ enum label_id { label_nopage_tlbm, label_smp_pgtable_change, label_r3000_write_probe_fail, + label_large_segbits_fault, #ifdef CONFIG_HUGETLB_PAGE label_tlb_huge_update, #endif @@ -101,6 +112,7 @@ 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_HUGETLB_PAGE UASM_L_LA(_tlb_huge_update) #endif @@ -157,6 +169,10 @@ static u32 tlb_handler[128] __cpuinitdata; static struct uasm_label labels[128] __cpuinitdata; static struct uasm_reloc relocs[128] __cpuinitdata; +#ifdef CONFIG_64BIT +static int check_for_high_segbits __cpuinitdata; +#endif + #ifndef CONFIG_MIPS_PGD_C0_CONTEXT /* * CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current, @@ -532,7 +548,24 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, * The vmalloc handling is not in the hotpath. */ uasm_i_dmfc0(p, tmp, C0_BADVADDR); - uasm_il_bltz(p, r, tmp, label_vmalloc); + + 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. */ #ifdef CONFIG_MIPS_PGD_C0_CONTEXT @@ -583,28 +616,64 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, #endif } +enum vmalloc64_mode {not_refill, refill}; /* * 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) + 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 (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)); + if (mode == 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 (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)); + } + } + if (mode == refill && check_for_high_segbits) { + uasm_l_large_segbits_fault(l, *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. + */ + UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0); + uasm_i_jr(p, ptr); + uasm_i_nop(p); } } @@ -823,7 +892,7 @@ static void __cpuinit build_r4000_tlb_refill_handler(void) #endif #ifdef CONFIG_64BIT - build_get_pgd_vmalloc64(&p, &l, &r, K0, K1); + build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, refill); #endif /* @@ -933,15 +1002,6 @@ static void __cpuinit build_r4000_tlb_refill_handler(void) } /* - * 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. */ @@ -1300,7 +1360,7 @@ build_r4000_tlbchange_handler_tail(u32 **p, struct uasm_label **l, uasm_i_eret(p); /* return from trap */ #ifdef CONFIG_64BIT - build_get_pgd_vmalloc64(p, l, r, tmp, ptr); + build_get_pgd_vmalloc64(p, l, r, tmp, ptr, not_refill); #endif } @@ -1524,6 +1584,10 @@ void __cpuinit build_tlb_refill_handler(void) */ static int run_once = 0; +#ifdef CONFIG_64BIT + check_for_high_segbits = current_cpu_data.vmbits > (PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3); +#endif + switch (current_cpu_type()) { case CPU_R2000: case CPU_R3000: |