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From:   Christophe Leroy <christophe.leroy@csgroup.eu>
To:     Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>
Cc:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>,
        stable@vger.kernel.org
Subject: [PATCH v1 1/3] powerpc: Fix eh field when calling lwarx on PPC32
Date:   Tue,  2 Aug 2022 11:02:36 +0200
Message-Id: <a1176e19e627dd6a1b8d24c6c457a8ab874b7d12.1659430931.git.christophe.leroy@csgroup.eu>
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Commit 9401f4e46cf6 ("powerpc: Use lwarx/ldarx directly instead of
PPC_LWARX/LDARX macros") properly handled the eh field of lwarx
in asm/bitops.h but failed to clear it for PPC32 in
asm/simple_spinlock.h

So, do as in arch_atomic_try_cmpxchg_lock(), set it to 1 if PPC64
but set it to 0 if PPC32. For that use IS_ENABLED(CONFIG_PPC64) which
returns 1 when CONFIG_PPC64 is set and 0 otherwise.

Reported-by: Pali Rohár <pali@kernel.org>
Fixes: 9401f4e46cf6 ("powerpc: Use lwarx/ldarx directly instead of PPC_LWARX/LDARX macros")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/simple_spinlock.h | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/simple_spinlock.h b/arch/powerpc/include/asm/simple_spinlock.h
index 7ae6aeef8464..5095c636a680 100644
--- a/arch/powerpc/include/asm/simple_spinlock.h
+++ b/arch/powerpc/include/asm/simple_spinlock.h
@@ -48,10 +48,11 @@ static inline int arch_spin_is_locked(arch_spinlock_t *lock)
 static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock)
 {
 	unsigned long tmp, token;
+	unsigned int eh = IS_ENABLED(CONFIG_PPC64);
 
 	token = LOCK_TOKEN;
 	__asm__ __volatile__(
-"1:	lwarx		%0,0,%2,1\n\
+"1:	lwarx		%0,0,%2,%3\n\
 	cmpwi		0,%0,0\n\
 	bne-		2f\n\
 	stwcx.		%1,0,%2\n\
@@ -59,7 +60,7 @@ static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock)
 	PPC_ACQUIRE_BARRIER
 "2:"
 	: "=&r" (tmp)
-	: "r" (token), "r" (&lock->slock)
+	: "r" (token), "r" (&lock->slock), "i" (eh)
 	: "cr0", "memory");
 
 	return tmp;
@@ -156,9 +157,10 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock)
 static inline long __arch_read_trylock(arch_rwlock_t *rw)
 {
 	long tmp;
+	unsigned int eh = IS_ENABLED(CONFIG_PPC64);
 
 	__asm__ __volatile__(
-"1:	lwarx		%0,0,%1,1\n"
+"1:	lwarx		%0,0,%1,%2\n"
 	__DO_SIGN_EXTEND
 "	addic.		%0,%0,1\n\
 	ble-		2f\n"
@@ -166,7 +168,7 @@ static inline long __arch_read_trylock(arch_rwlock_t *rw)
 	bne-		1b\n"
 	PPC_ACQUIRE_BARRIER
 "2:"	: "=&r" (tmp)
-	: "r" (&rw->lock)
+	: "r" (&rw->lock), "i" (eh)
 	: "cr0", "xer", "memory");
 
 	return tmp;
@@ -179,17 +181,18 @@ static inline long __arch_read_trylock(arch_rwlock_t *rw)
 static inline long __arch_write_trylock(arch_rwlock_t *rw)
 {
 	long tmp, token;
+	unsigned int eh = IS_ENABLED(CONFIG_PPC64);
 
 	token = WRLOCK_TOKEN;
 	__asm__ __volatile__(
-"1:	lwarx		%0,0,%2,1\n\
+"1:	lwarx		%0,0,%2,%3\n\
 	cmpwi		0,%0,0\n\
 	bne-		2f\n"
 "	stwcx.		%1,0,%2\n\
 	bne-		1b\n"
 	PPC_ACQUIRE_BARRIER
 "2:"	: "=&r" (tmp)
-	: "r" (token), "r" (&rw->lock)
+	: "r" (token), "r" (&rw->lock), "i" (eh)
 	: "cr0", "memory");
 
 	return tmp;
-- 
2.36.1