[RFC PATCH v3 04/15] powerpc/8xx: Create C version of kuap_restore() and kuap_check()

[Christophe Leroy <christophe.leroy@c-s.fr>]

In preparation of porting PPC32 to C syscall entry/exit,
create C version of kuap_restore() and kuap_check() on 8xx

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/nohash/32/kup-8xx.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 85ed2390fb99..1918d2e55da3 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -34,6 +34,19 @@
 
 #include <asm/reg.h>
 
+static inline void kuap_restore(struct pt_regs *regs)
+{
+	mtspr(SPRN_MD_AP, regs->kuap);
+}
+
+static inline void kuap_check(void)
+{
+	if (!IS_ENABLED(CONFIG_PPC_KUAP_DEBUG))
+		return;
+
+	WARN_ON_ONCE((mfspr(SPRN_MD_AP) & 0xffff0000) != (MD_APG_KUAP & 0xffff0000));
+}
+
 static inline void allow_user_access(void __user *to, const void __user *from,
 				     unsigned long size, unsigned long dir)
 {
-- 
2.25.0