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Diffstat (limited to 'arch/xtensa/mm/tlb.c')
-rw-r--r--arch/xtensa/mm/tlb.c120
1 files changed, 117 insertions, 3 deletions
diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c
index 5411aa67c68e..ca9d2366bf12 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 */