In preparation of porting PPC32 to C syscall entry/exit,
create C version of kuap_save_and_lock() and kuap_user_restore() and
kuap_kernel_restore() and kuap_check() and kuap_get_and_check()
on book3s/32.

Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
 arch/powerpc/include/asm/book3s/32/kup.h | 45 ++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h 
b/arch/powerpc/include/asm/book3s/32/kup.h
index b97ea60f6fa3..c9d6c28bcd10 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -72,6 +72,51 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)
        isync();        /* Context sync required after mtsr() */
 }
 
+static inline void kuap_save_and_lock(struct pt_regs *regs)
+{
+       unsigned long kuap = current->thread.kuap;
+       u32 addr = kuap & 0xf0000000;
+       u32 end = kuap << 28;
+
+       regs->kuap = kuap;
+       if (unlikely(!kuap))
+               return;
+
+       current->thread.kuap = 0;
+       kuap_update_sr(mfsr(addr) | SR_KS, addr, end);  /* Set Ks */
+}
+
+static inline void kuap_user_restore(struct pt_regs *regs)
+{
+}
+
+static inline void kuap_kernel_restore(struct pt_regs *regs, unsigned long 
kuap)
+{
+       u32 addr = regs->kuap & 0xf0000000;
+       u32 end = regs->kuap << 28;
+
+       current->thread.kuap = regs->kuap;
+
+       if (unlikely(regs->kuap == kuap))
+               return;
+
+       kuap_update_sr(mfsr(addr) & ~SR_KS, addr, end); /* Clear Ks */
+}
+
+static inline unsigned long kuap_get_and_check(void)
+{
+       unsigned long kuap = current->thread.kuap;
+
+       WARN_ON_ONCE(IS_ENABLED(CONFIG_PPC_KUAP_DEBUG) && kuap != 0);
+
+       return kuap;
+}
+
+static inline void kuap_check(void)
+{
+       kuap_get_and_check();
+}
+
 static __always_inline void allow_user_access(void __user *to, const void 
__user *from,
                                              u32 size, unsigned long dir)
 {
-- 
2.25.0

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