powerpc/32: Replace ASM exception exit by C exception exit from ppc64

This patch replaces the PPC32 ASM exception exit by C exception exit.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/48f8bae91da899d8e73fc0d75c9af66cc97b4d5b.1615552867.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/interrupt.c

@@ -20,6 +20,10 @@
 #include <asm/time.h>
 #include <asm/unistd.h>
 
+#if defined(CONFIG_PPC_ADV_DEBUG_REGS) && defined(CONFIG_PPC32)
+unsigned long global_dbcr0[NR_CPUS];
+#endif
+
 typedef long (*syscall_fn)(long, long, long, long, long, long);
 
 /* Has to run notrace because it is entered not completely "reconciled" */
@@ -392,7 +396,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
 		ti_flags = READ_ONCE(current_thread_info()->flags);
 	}
 
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && IS_ENABLED(CONFIG_PPC_FPU)) {
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && IS_ENABLED(CONFIG_PPC_FPU)) {
 		if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
 				unlikely((ti_flags & _TIF_RESTORE_TM))) {
 			restore_tm_state(regs);