1 files changed, 53 insertions, 2 deletions

diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index c363e850550e..c3bfef08dcf8 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1519,8 +1519,8 @@ static bool should_hash_preload(struct mm_struct *mm, unsigned long ea)
 }
 #endif
 
-void hash_preload(struct mm_struct *mm, unsigned long ea,
-		  bool is_exec, unsigned long trap)
+static void hash_preload(struct mm_struct *mm, unsigned long ea,
+			 bool is_exec, unsigned long trap)
 {
 	int hugepage_shift;
 	unsigned long vsid;
@@ -1600,6 +1600,57 @@ out_exit:
 	local_irq_restore(flags);
 }
 
+/*
+ * This is called at the end of handling a user page fault, when the
+ * fault has been handled by updating a PTE in the linux page tables.
+ * We use it to preload an HPTE into the hash table corresponding to
+ * the updated linux PTE.
+ *
+ * This must always be called with the pte lock held.
+ */
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+		      pte_t *ptep)
+{
+	/*
+	 * We don't need to worry about _PAGE_PRESENT here because we are
+	 * called with either mm->page_table_lock held or ptl lock held
+	 */
+	unsigned long trap;
+	bool is_exec;
+
+	if (radix_enabled()) {
+		prefetch((void *)address);
+		return;
+	}
+
+	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
+	if (!pte_young(*ptep) || address >= TASK_SIZE)
+		return;
+
+	/*
+	 * We try to figure out if we are coming from an instruction
+	 * access fault and pass that down to __hash_page so we avoid
+	 * double-faulting on execution of fresh text. We have to test
+	 * for regs NULL since init will get here first thing at boot.
+	 *
+	 * We also avoid filling the hash if not coming from a fault.
+	 */
+
+	trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
+	switch (trap) {
+	case 0x300:
+		is_exec = false;
+		break;
+	case 0x400:
+		is_exec = true;
+		break;
+	default:
+		return;
+	}
+
+	hash_preload(vma->vm_mm, address, is_exec, trap);
+}
+
 #ifdef CONFIG_PPC_MEM_KEYS
 /*
  * Return the protection key associated with the given address and the