powerpc/mm/radix: Add tlb flush of THP ptes

Instead of flushing the entire mm, implement a flush_pmd_tlb_range

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/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
index 4d0f03a..456c155 100644
--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -391,3 +391,10 @@
 	asm volatile("eieio; tlbsync; ptesync": : :"memory");
 }
 EXPORT_SYMBOL(radix__flush_tlb_lpid);
+
+void radix__flush_pmd_tlb_range(struct vm_area_struct *vma,
+				unsigned long start, unsigned long end)
+{
+	radix__flush_tlb_range_psize(vma->vm_mm, start, end, MMU_PAGE_2M);
+}
+EXPORT_SYMBOL(radix__flush_pmd_tlb_range);