[RFC 2/6] powerpc/mm/book3s64: Rework tlbie() to remove conditional locking

[Ritesh Harjani (IBM)]

Clang's context analysis reports:
 hash_native.c:235:2: error: raw_spinlock 'native_tlbie_lock' is not held on every path through here [-Werror,-Wthread-safety-analysis]
 hash_native.c:245:3: error: releasing raw_spinlock 'native_tlbie_lock' that was not held [-Werror,-Wthread-safety-analysis]

This patch reworks the tlbie() function to remove the conditional
locking. It fixes the clang context analysis reported errors. However,
this also simplifies the code around tlbie[l] - which is also a win.

No functional change intended.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
---
 arch/powerpc/mm/book3s64/hash_native.c | 34 ++++++++++++++++++--------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/hash_native.c b/arch/powerpc/mm/book3s64/hash_native.c
index ab2a80e59011..6bad0545b57a 100644
--- a/arch/powerpc/mm/book3s64/hash_native.c
+++ b/arch/powerpc/mm/book3s64/hash_native.c
@@ -222,6 +222,23 @@ static inline void __tlbiel(unsigned long vpn, int psize, int apsize, int ssize)
 
 }
 
+static inline void __tlbie_sequence(unsigned long vpn, int psize, int apsize,
+				    int ssize)
+{
+	asm volatile("ptesync": : :"memory");
+	__tlbie(vpn, psize, apsize, ssize);
+	fixup_tlbie_vpn(vpn, psize, apsize, ssize);
+	asm volatile("eieio; tlbsync; ptesync": : :"memory");
+}
+
+static inline void __tlbiel_sequence(unsigned long vpn, int psize, int apsize,
+				     int ssize)
+{
+	asm volatile("ptesync": : :"memory");
+	__tlbiel(vpn, psize, apsize, ssize);
+	ppc_after_tlbiel_barrier();
+}
+
 static inline void tlbie(unsigned long vpn, int psize, int apsize,
 			 int ssize, int local)
 {
@@ -230,19 +247,16 @@ static inline void tlbie(unsigned long vpn, int psize, int apsize,
 
 	if (use_local)
 		use_local = mmu_psize_defs[psize].tlbiel;
-	if (lock_tlbie && !use_local)
-		raw_spin_lock(&native_tlbie_lock);
-	asm volatile("ptesync": : :"memory");
+
 	if (use_local) {
-		__tlbiel(vpn, psize, apsize, ssize);
-		ppc_after_tlbiel_barrier();
+		__tlbiel_sequence(vpn, psize, apsize, ssize);
+	} else if (lock_tlbie) {
+		raw_spin_lock(&native_tlbie_lock);
+		__tlbie_sequence(vpn, psize, apsize, ssize);
+		raw_spin_unlock(&native_tlbie_lock);
 	} else {
-		__tlbie(vpn, psize, apsize, ssize);
-		fixup_tlbie_vpn(vpn, psize, apsize, ssize);
-		asm volatile("eieio; tlbsync; ptesync": : :"memory");
+		__tlbie_sequence(vpn, psize, apsize, ssize);
 	}
-	if (lock_tlbie && !use_local)
-		raw_spin_unlock(&native_tlbie_lock);
 }
 
 static inline void native_lock_hpte(struct hash_pte *hptep)
-- 
2.39.5