diff options
Diffstat (limited to 'include/linux/hwspinlock.h')
| -rw-r--r-- | include/linux/hwspinlock.h | 61 |
1 files changed, 58 insertions, 3 deletions
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index 0afe693be5f4..bfe7c1f1ac6d 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -14,9 +14,10 @@ #include <linux/sched.h> /* hwspinlock mode argument */ -#define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */ -#define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ -#define HWLOCK_RAW 0x03 +#define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */ +#define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ +#define HWLOCK_RAW 0x03 +#define HWLOCK_IN_ATOMIC 0x04 /* Called while in atomic context */ struct device; struct device_node; @@ -223,6 +224,23 @@ static inline int hwspin_trylock_raw(struct hwspinlock *hwlock) } /** + * hwspin_trylock_in_atomic() - attempt to lock a specific hwspinlock + * @hwlock: an hwspinlock which we want to trylock + * + * This function attempts to lock an hwspinlock, and will immediately fail + * if the hwspinlock is already taken. + * + * This function shall be called only from an atomic context. + * + * Returns 0 if we successfully locked the hwspinlock, -EBUSY if + * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. + */ +static inline int hwspin_trylock_in_atomic(struct hwspinlock *hwlock) +{ + return __hwspin_trylock(hwlock, HWLOCK_IN_ATOMIC, NULL); +} + +/** * hwspin_trylock() - attempt to lock a specific hwspinlock * @hwlock: an hwspinlock which we want to trylock * @@ -313,6 +331,28 @@ int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to) } /** + * hwspin_lock_timeout_in_atomic() - lock an hwspinlock with timeout limit + * @hwlock: the hwspinlock to be locked + * @to: timeout value in msecs + * + * This function locks the underlying @hwlock. If the @hwlock + * is already taken, the function will busy loop waiting for it to + * be released, but give up when @timeout msecs have elapsed. + * + * This function shall be called only from an atomic context and the timeout + * value shall not exceed a few msecs. + * + * Returns 0 when the @hwlock was successfully taken, and an appropriate + * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still + * busy after @timeout msecs). The function will never sleep. + */ +static inline +int hwspin_lock_timeout_in_atomic(struct hwspinlock *hwlock, unsigned int to) +{ + return __hwspin_lock_timeout(hwlock, to, HWLOCK_IN_ATOMIC, NULL); +} + +/** * hwspin_lock_timeout() - lock an hwspinlock with timeout limit * @hwlock: the hwspinlock to be locked * @to: timeout value in msecs @@ -387,6 +427,21 @@ static inline void hwspin_unlock_raw(struct hwspinlock *hwlock) } /** + * hwspin_unlock_in_atomic() - unlock hwspinlock + * @hwlock: a previously-acquired hwspinlock which we want to unlock + * + * This function will unlock a specific hwspinlock. + * + * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling + * this function: it is a bug to call unlock on a @hwlock that is already + * unlocked. + */ +static inline void hwspin_unlock_in_atomic(struct hwspinlock *hwlock) +{ + __hwspin_unlock(hwlock, HWLOCK_IN_ATOMIC, NULL); +} + +/** * hwspin_unlock() - unlock hwspinlock * @hwlock: a previously-acquired hwspinlock which we want to unlock * |