powerpc/64s/hash: Provide arch_setup_exec() hooks for hash slice setup

This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/process.c

@@ -1490,6 +1490,15 @@ void flush_thread(void)
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 }
 
+#ifdef CONFIG_PPC_BOOK3S_64
+void arch_setup_new_exec(void)
+{
+	if (radix_enabled())
+		return;
+	hash__setup_new_exec();
+}
+#endif
+
 int set_thread_uses_vas(void)
 {
 #ifdef CONFIG_PPC_BOOK3S_64