powerpc/mm: Add radix__tlb_flush_pte_p9_dd1()

Now that we have page size details encoded in pte using software pte
bits, use that to find the page size needed for tlb flush.

This function should only be used on P9 DD1, so give it a horrible name
to make that clear.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/book3s/64/tlbflush-radix.h

@@ -42,4 +42,6 @@ extern void radix__flush_tlb_lpid_va(unsigned long lpid, unsigned long gpa,
 				     unsigned long page_size);
 extern void radix__flush_tlb_lpid(unsigned long lpid);
 extern void radix__flush_tlb_all(void);
+extern void radix__flush_tlb_pte_p9_dd1(unsigned long old_pte, struct mm_struct *mm,
+					unsigned long address);
 #endif

arch/powerpc/mm/tlb-radix.c

@@ -424,3 +424,21 @@ void radix__flush_tlb_all(void)
 		     : : "r"(rb), "i"(r), "i"(prs), "i"(ric), "r"(0) : "memory");
 	asm volatile("eieio; tlbsync; ptesync": : :"memory");
 }
+
+void radix__flush_tlb_pte_p9_dd1(unsigned long old_pte, struct mm_struct *mm,
+				 unsigned long address)
+{
+	/*
+	 * We track page size in pte only for DD1, So we can
+	 * call this only on DD1.
+	 */
+	if (!cpu_has_feature(CPU_FTR_POWER9_DD1)) {
+		VM_WARN_ON(1);
+		return;
+	}
+
+	if (old_pte & _PAGE_LARGE)
+		radix__flush_tlb_page_psize(mm, address, MMU_PAGE_2M);
+	else
+		radix__flush_tlb_page_psize(mm, address, mmu_virtual_psize);
+}