in stm32_hwspinlock.c [28:37]
static int stm32_hwspinlock_trylock(struct hwspinlock *lock)
{
void __iomem *lock_addr = lock->priv;
u32 status;
writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID, lock_addr);
status = readl(lock_addr);
return status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID);
}