powerpc: Fix eh field when calling lwarx on PPC32

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.

Fixes: 9401f4e46cf6 ("powerpc: Use lwarx/ldarx directly instead of PPC_LWARX/LDARX macros")
Cc: stable@vger.kernel.org # v5.15+
Reported-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Use symbolic names, use 'n' constraint per Segher]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a1176e19e627dd6a1b8d24c6c457a8ab874b7d12.1659430931.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/simple_spinlock.h b/arch/powerpc/include/asm/simple_spinlock.h
index 7ae6aee..9dcc7e9 100644 (file)
--- 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,%[eh]\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), [eh] "n" (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,%[eh]\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), [eh] "n" (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,%[eh]\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), [eh] "n" (eh)
        : "cr0", "memory");
 
        return tmp;