diff options
Diffstat (limited to 'arch/arc/include/asm/spinlock.h')
| -rw-r--r-- | arch/arc/include/asm/spinlock.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h index a325e6a36523..47efc8451b70 100644 --- a/arch/arc/include/asm/spinlock.h +++ b/arch/arc/include/asm/spinlock.h @@ -247,9 +247,15 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) __asm__ __volatile__( "1: ex %0, [%1] \n" +#ifdef CONFIG_EZNPS_MTM_EXT + " .word %3 \n" +#endif " breq %0, %2, 1b \n" : "+&r" (val) : "r"(&(lock->slock)), "ir"(__ARCH_SPIN_LOCK_LOCKED__) +#ifdef CONFIG_EZNPS_MTM_EXT + , "i"(CTOP_INST_SCHD_RW) +#endif : "memory"); /* @@ -291,6 +297,12 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock) */ smp_mb(); + /* + * EX is not really required here, a simple STore of 0 suffices. + * However this causes tasklist livelocks in SystemC based SMP virtual + * platforms where the systemc core scheduler uses EX as a cue for + * moving to next core. Do a git log of this file for details + */ __asm__ __volatile__( " ex %0, [%1] \n" : "+r" (val) |