powerpc/mm: Use H_READ with H_READ_4

This will bulk read 4 hash pte slot entries and should reduce the loop

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/plpar_wrappers.h b/arch/powerpc/include/asm/plpar_wrappers.h
index 67859ed..1b39424 100644
--- a/arch/powerpc/include/asm/plpar_wrappers.h
+++ b/arch/powerpc/include/asm/plpar_wrappers.h
@@ -202,6 +202,23 @@
 }
 
 /*
+ * ptes must be 8*sizeof(unsigned long)
+ */
+static inline long plpar_pte_read_4(unsigned long flags, unsigned long ptex,
+				    unsigned long *ptes)
+
+{
+	long rc;
+	unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
+
+	rc = plpar_hcall9(H_READ, retbuf, flags | H_READ_4, ptex);
+
+	memcpy(ptes, retbuf, 8*sizeof(unsigned long));
+
+	return rc;
+}
+
+/*
  * plpar_pte_read_4_raw can be called in real mode.
  * ptes must be 8*sizeof(unsigned long)
  */