1 files changed, 59 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pte-walk.h b/arch/powerpc/include/asm/pte-walk.h
new file mode 100644
index 000000000..33fa5dd8e
--- /dev/null
+++ b/arch/powerpc/include/asm/pte-walk.h
@@ -0,0 +1,59 @@
+#ifndef _ASM_POWERPC_PTE_WALK_H
+#define _ASM_POWERPC_PTE_WALK_H
+
+#include <linux/sched.h>
+
+/* Don't use this directly */
+extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
+			       bool *is_thp, unsigned *hshift);
+
+static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
+				    bool *is_thp, unsigned *hshift)
+{
+	pte_t *pte;
+
+	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
+	pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
+
+#if defined(CONFIG_DEBUG_VM) &&						\
+	!(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
+	/*
+	 * We should not find huge page if these configs are not enabled.
+	 */
+	if (hshift)
+		WARN_ON(*hshift);
+#endif
+	return pte;
+}
+
+static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
+{
+	pgd_t *pgdir = init_mm.pgd;
+	return __find_linux_pte(pgdir, ea, NULL, hshift);
+}
+/*
+ * This is what we should always use. Any other lockless page table lookup needs
+ * careful audit against THP split.
+ */
+static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
+					 bool *is_thp, unsigned *hshift)
+{
+	pte_t *pte;
+
+	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
+	VM_WARN(pgdir != current->mm->pgd,
+		"%s lock less page table lookup called on wrong mm\n", __func__);
+	pte = __find_linux_pte(pgdir, ea, is_thp, hshift);
+
+#if defined(CONFIG_DEBUG_VM) &&						\
+	!(defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE))
+	/*
+	 * We should not find huge page if these configs are not enabled.
+	 */
+	if (hshift)
+		WARN_ON(*hshift);
+#endif
+	return pte;
+}
+
+#endif /* _ASM_POWERPC_PTE_WALK_H */