diff options
Diffstat (limited to 'arch/xtensa/mm/tlb.c')
| -rw-r--r-- | arch/xtensa/mm/tlb.c | 120 |
1 files changed, 117 insertions, 3 deletions
diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c index 5411aa67c68..ca9d2366bf1 100644 --- a/arch/xtensa/mm/tlb.c +++ b/arch/xtensa/mm/tlb.c @@ -64,7 +64,7 @@ void flush_tlb_mm(struct mm_struct *mm) { if (mm == current->active_mm) { unsigned long flags; - local_save_flags(flags); + local_irq_save(flags); __get_new_mmu_context(mm); __load_mmu_context(mm); local_irq_restore(flags); @@ -94,7 +94,7 @@ void flush_tlb_range (struct vm_area_struct *vma, printk("[tlbrange<%02lx,%08lx,%08lx>]\n", (unsigned long)mm->context, start, end); #endif - local_save_flags(flags); + local_irq_save(flags); if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) { int oldpid = get_rasid_register(); @@ -128,9 +128,10 @@ void flush_tlb_page (struct vm_area_struct *vma, unsigned long page) if(mm->context == NO_CONTEXT) return; - local_save_flags(flags); + local_irq_save(flags); oldpid = get_rasid_register(); + set_rasid_register(ASID_INSERT(mm->context)); if (vma->vm_flags & VM_EXEC) invalidate_itlb_mapping(page); @@ -140,3 +141,116 @@ void flush_tlb_page (struct vm_area_struct *vma, unsigned long page) local_irq_restore(flags); } + +#ifdef CONFIG_DEBUG_TLB_SANITY + +static unsigned get_pte_for_vaddr(unsigned vaddr) +{ + struct task_struct *task = get_current(); + struct mm_struct *mm = task->mm; + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + + if (!mm) + mm = task->active_mm; + pgd = pgd_offset(mm, vaddr); + if (pgd_none_or_clear_bad(pgd)) + return 0; + pmd = pmd_offset(pgd, vaddr); + if (pmd_none_or_clear_bad(pmd)) + return 0; + pte = pte_offset_map(pmd, vaddr); + if (!pte) + return 0; + return pte_val(*pte); +} + +enum { + TLB_SUSPICIOUS = 1, + TLB_INSANE = 2, +}; + +static void tlb_insane(void) +{ + BUG_ON(1); +} + +static void tlb_suspicious(void) +{ + WARN_ON(1); +} + +/* + * Check that TLB entries with kernel ASID (1) have kernel VMA (>= TASK_SIZE), + * and TLB entries with user ASID (>=4) have VMA < TASK_SIZE. + * + * Check that valid TLB entries either have the same PA as the PTE, or PTE is + * marked as non-present. Non-present PTE and the page with non-zero refcount + * and zero mapcount is normal for batched TLB flush operation. Zero refcount + * means that the page was freed prematurely. Non-zero mapcount is unusual, + * but does not necessary means an error, thus marked as suspicious. + */ +static int check_tlb_entry(unsigned w, unsigned e, bool dtlb) +{ + unsigned tlbidx = w | (e << PAGE_SHIFT); + unsigned r0 = dtlb ? + read_dtlb_virtual(tlbidx) : read_itlb_virtual(tlbidx); + unsigned vpn = (r0 & PAGE_MASK) | (e << PAGE_SHIFT); + unsigned pte = get_pte_for_vaddr(vpn); + unsigned mm_asid = (get_rasid_register() >> 8) & ASID_MASK; + unsigned tlb_asid = r0 & ASID_MASK; + bool kernel = tlb_asid == 1; + int rc = 0; + + if (tlb_asid > 0 && ((vpn < TASK_SIZE) == kernel)) { + pr_err("%cTLB: way: %u, entry: %u, VPN %08x in %s PTE\n", + dtlb ? 'D' : 'I', w, e, vpn, + kernel ? "kernel" : "user"); + rc |= TLB_INSANE; + } + + if (tlb_asid == mm_asid) { + unsigned r1 = dtlb ? read_dtlb_translation(tlbidx) : + read_itlb_translation(tlbidx); + if ((pte ^ r1) & PAGE_MASK) { + pr_err("%cTLB: way: %u, entry: %u, mapping: %08x->%08x, PTE: %08x\n", + dtlb ? 'D' : 'I', w, e, r0, r1, pte); + if (pte == 0 || !pte_present(__pte(pte))) { + struct page *p = pfn_to_page(r1 >> PAGE_SHIFT); + pr_err("page refcount: %d, mapcount: %d\n", + page_count(p), + page_mapcount(p)); + if (!page_count(p)) + rc |= TLB_INSANE; + else if (page_mapped(p)) + rc |= TLB_SUSPICIOUS; + } else { + rc |= TLB_INSANE; + } + } + } + return rc; +} + +void check_tlb_sanity(void) +{ + unsigned long flags; + unsigned w, e; + int bug = 0; + + local_irq_save(flags); + for (w = 0; w < DTLB_ARF_WAYS; ++w) + for (e = 0; e < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); ++e) + bug |= check_tlb_entry(w, e, true); + for (w = 0; w < ITLB_ARF_WAYS; ++w) + for (e = 0; e < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); ++e) + bug |= check_tlb_entry(w, e, false); + if (bug & TLB_INSANE) + tlb_insane(); + if (bug & TLB_SUSPICIOUS) + tlb_suspicious(); + local_irq_restore(flags); +} + +#endif /* CONFIG_DEBUG_TLB_SANITY */ |