Revert "powerpc: Inline setup_kup()"

This reverts commit 1791ebd1.

setup_kup() was inlined to manage conflict between PPC32 marking
setup_{kuap/kuep}() __init and PPC64 not marking them __init.

But in fact PPC32 has removed the __init mark for all but 8xx
in order to properly handle SMP.

In order to make setup_kup() grow a bit, revert the commit
mentioned above but remove __init for 8xx as well so that
we don't have to mark setup_kup() as __ref.

Also switch the order so that KUAP is initialised before KUEP
because on the 40x, KUEP will depend on the activation of KUAP.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7691088fd0994ee3c8db6298dc8c00259e3f6a7f.1634627931.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/kup.h

@@ -32,6 +32,8 @@ extern bool disable_kuap;
 
 #include <linux/pgtable.h>
 
+void setup_kup(void);
+
 #ifdef CONFIG_PPC_KUEP
 void setup_kuep(bool disabled);
 #else
@@ -78,12 +80,6 @@ static inline void restore_user_access(unsigned long flags) { }
 #endif /* CONFIG_PPC_BOOK3S_64 */
 #endif /* CONFIG_PPC_KUAP */
 
-static __always_inline void setup_kup(void)
-{
-	setup_kuep(disable_kuep);
-	setup_kuap(disable_kuap);
-}
-
 static __always_inline void allow_read_from_user(const void __user *from, unsigned long size)
 {
 	barrier_nospec();

arch/powerpc/mm/init-common.c

@@ -47,6 +47,12 @@ static int __init parse_nosmap(char *p)
 }
 early_param("nosmap", parse_nosmap);
 
+void setup_kup(void)
+{
+	setup_kuap(disable_kuap);
+	setup_kuep(disable_kuep);
+}
+
 #define CTOR(shift) static void ctor_##shift(void *addr) \
 {							\
 	memset(addr, 0, sizeof(void *) << (shift));	\

arch/powerpc/mm/nohash/8xx.c

@@ -213,7 +213,7 @@ void __init setup_initial_memory_limit(phys_addr_t first_memblock_base,
 }
 
 #ifdef CONFIG_PPC_KUEP
-void __init setup_kuep(bool disabled)
+void setup_kuep(bool disabled)
 {
 	if (disabled)
 		return;
@@ -228,7 +228,7 @@ void __init setup_kuep(bool disabled)
 struct static_key_false disable_kuap_key;
 EXPORT_SYMBOL(disable_kuap_key);
 
-void __init setup_kuap(bool disabled)
+void setup_kuap(bool disabled)
 {
 	if (disabled) {
 		static_branch_enable(&disable_kuap_key);