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-rw-r--r--arch/xtensa/mm/tlb.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c
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+++ b/arch/xtensa/mm/tlb.c
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+/*
+ * arch/xtensa/mm/tlb.c
+ *
+ * Logic that manipulates the Xtensa MMU. Derived from MIPS.
+ *
+ * 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.
+ *
+ * Copyright (C) 2001 - 2003 Tensilica Inc.
+ *
+ * Joe Taylor
+ * Chris Zankel <chris@zankel.net>
+ * Marc Gauthier
+ */
+
+#include <linux/mm.h>
+#include <asm/processor.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
+
+
+static inline void __flush_itlb_all (void)
+{
+ int w, i;
+
+ for (w = 0; w < ITLB_ARF_WAYS; w++) {
+ for (i = 0; i < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); i++) {
+ int e = w + (i << PAGE_SHIFT);
+ invalidate_itlb_entry_no_isync(e);
+ }
+ }
+ asm volatile ("isync\n");
+}
+
+static inline void __flush_dtlb_all (void)
+{
+ int w, i;
+
+ for (w = 0; w < DTLB_ARF_WAYS; w++) {
+ for (i = 0; i < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); i++) {
+ int e = w + (i << PAGE_SHIFT);
+ invalidate_dtlb_entry_no_isync(e);
+ }
+ }
+ asm volatile ("isync\n");
+}
+
+
+void local_flush_tlb_all(void)
+{
+ __flush_itlb_all();
+ __flush_dtlb_all();
+}
+
+/* If mm is current, we simply assign the current task a new ASID, thus,
+ * invalidating all previous tlb entries. If mm is someone else's user mapping,
+ * wie invalidate the context, thus, when that user mapping is swapped in,
+ * a new context will be assigned to it.
+ */
+
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+ int cpu = smp_processor_id();
+
+ if (mm == current->active_mm) {
+ unsigned long flags;
+ local_irq_save(flags);
+ mm->context.asid[cpu] = NO_CONTEXT;
+ activate_context(mm, cpu);
+ local_irq_restore(flags);
+ } else {
+ mm->context.asid[cpu] = NO_CONTEXT;
+ mm->context.cpu = -1;
+ }
+}
+
+
+#define _ITLB_ENTRIES (ITLB_ARF_WAYS << XCHAL_ITLB_ARF_ENTRIES_LOG2)
+#define _DTLB_ENTRIES (DTLB_ARF_WAYS << XCHAL_DTLB_ARF_ENTRIES_LOG2)
+#if _ITLB_ENTRIES > _DTLB_ENTRIES
+# define _TLB_ENTRIES _ITLB_ENTRIES
+#else
+# define _TLB_ENTRIES _DTLB_ENTRIES
+#endif
+
+void local_flush_tlb_range(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ int cpu = smp_processor_id();
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long flags;
+
+ if (mm->context.asid[cpu] == NO_CONTEXT)
+ return;
+
+ pr_debug("[tlbrange<%02lx,%08lx,%08lx>]\n",
+ (unsigned long)mm->context.asid[cpu], start, end);
+ local_irq_save(flags);
+
+ if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
+ int oldpid = get_rasid_register();
+
+ set_rasid_register(ASID_INSERT(mm->context.asid[cpu]));
+ start &= PAGE_MASK;
+ if (vma->vm_flags & VM_EXEC)
+ while(start < end) {
+ invalidate_itlb_mapping(start);
+ invalidate_dtlb_mapping(start);
+ start += PAGE_SIZE;
+ }
+ else
+ while(start < end) {
+ invalidate_dtlb_mapping(start);
+ start += PAGE_SIZE;
+ }
+
+ set_rasid_register(oldpid);
+ } else {
+ local_flush_tlb_mm(mm);
+ }
+ local_irq_restore(flags);
+}
+
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+ int cpu = smp_processor_id();
+ struct mm_struct* mm = vma->vm_mm;
+ unsigned long flags;
+ int oldpid;
+
+ if (mm->context.asid[cpu] == NO_CONTEXT)
+ return;
+
+ local_irq_save(flags);
+
+ oldpid = get_rasid_register();
+ set_rasid_register(ASID_INSERT(mm->context.asid[cpu]));
+
+ if (vma->vm_flags & VM_EXEC)
+ invalidate_itlb_mapping(page);
+ invalidate_dtlb_mapping(page);
+
+ set_rasid_register(oldpid);
+
+ local_irq_restore(flags);
+}
+
+void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+ if (end > start && start >= TASK_SIZE && end <= PAGE_OFFSET &&
+ end - start < _TLB_ENTRIES << PAGE_SHIFT) {
+ start &= PAGE_MASK;
+ while (start < end) {
+ invalidate_itlb_mapping(start);
+ invalidate_dtlb_mapping(start);
+ start += PAGE_SIZE;
+ }
+ } else {
+ local_flush_tlb_all();
+ }
+}
+
+void update_mmu_tlb(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep)
+{
+ local_flush_tlb_page(vma, address);
+}
+
+#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;
+ p4d_t *p4d;
+ pud_t *pud;
+ 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;
+ p4d = p4d_offset(pgd, vaddr);
+ if (p4d_none_or_clear_bad(p4d))
+ return 0;
+ pud = pud_offset(p4d, vaddr);
+ if (pud_none_or_clear_bad(pud))
+ return 0;
+ pmd = pmd_offset(pud, 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 r1 = dtlb ?
+ read_dtlb_translation(tlbidx) : read_itlb_translation(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) {
+ 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_mapcount(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 */