[PATCH 1/2] hwspinlock: document the hwspinlock 'raw' API
From: Fabien Dessenne <hidden>
Date: 2019-03-07 15:58:50
Also in:
linux-remoteproc, lkml
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
Document the hwspin_lock_timeout_raw(), hwspin_trylock_raw() and hwspin_unlock_raw() API. Signed-off-by: Fabien Dessenne <redacted> --- Documentation/hwspinlock.txt | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+)
diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt
index ed640a2..c3403f9 100644
--- a/Documentation/hwspinlock.txt
+++ b/Documentation/hwspinlock.txt@@ -136,6 +136,23 @@ The function will never sleep. :: + int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int timeout); + +Lock a previously-assigned hwspinlock with a timeout limit (specified in +msecs). If the hwspinlock is already taken, the function will busy loop +waiting for it to be released, but give up when the timeout elapses. + +Caution: User must protect the routine of getting hardware lock with mutex +or spinlock to avoid dead-lock, that will let user can do some time-consuming +or sleepable operations under the hardware lock. + +Returns 0 when successful and an appropriate error code otherwise (most +notably -ETIMEDOUT if the hwspinlock is still busy after timeout msecs). + +The function will never sleep. + +:: + int hwspin_trylock(struct hwspinlock *hwlock);
@@ -186,6 +203,21 @@ The function will never sleep. :: + int hwspin_trylock_raw(struct hwspinlock *hwlock); + +Attempt to lock a previously-assigned hwspinlock, but immediately fail if +it is already taken. + +Caution: User must protect the routine of getting hardware lock with mutex +or spinlock to avoid dead-lock, that will let user can do some time-consuming +or sleepable operations under the hardware lock. + +Returns 0 on success and an appropriate error code otherwise (most +notably -EBUSY if the hwspinlock was already taken). +The function will never sleep. + +:: + void hwspin_unlock(struct hwspinlock *hwlock); Unlock a previously-locked hwspinlock. Always succeed, and can be called
@@ -222,6 +254,16 @@ the given flags. This function will never sleep. :: + void hwspin_unlock_raw(struct hwspinlock *hwlock); + +Unlock a previously-locked hwspinlock. + +The caller should **never** unlock an hwspinlock which is already unlocked. +Doing so is considered a bug (there is no protection against this). +This function will never sleep. + +:: + int hwspin_lock_get_id(struct hwspinlock *hwlock); Retrieve id number of a given hwspinlock. This is needed when an
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2.7.4