diff options
| author | Richard Maina <quic_rmaina@quicinc.com> | 2024-05-29 11:09:55 -0700 |
|---|---|---|
| committer | Bjorn Andersson <andersson@kernel.org> | 2024-05-29 12:52:26 -0700 |
| commit | 7c327d56597d8de1680cf24e956b704270d3d84a (patch) | |
| tree | 46e51f75c8a0a7c15e25938abbf0ab770ed05dce /drivers/hwspinlock/hwspinlock_core.c | |
| parent | 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0 (diff) | |
hwspinlock: Introduce hwspin_lock_bust()
When a remoteproc crashes or goes down unexpectedly this can result in
a state where locks held by the remoteproc will remain locked possibly
resulting in deadlock. This new API hwspin_lock_bust() allows
hwspinlock implementers to define a bust operation for freeing previously
acquired hwspinlocks after verifying ownership of the acquired lock.
Signed-off-by: Richard Maina <quic_rmaina@quicinc.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Link: https://lore.kernel.org/r/20240529-hwspinlock-bust-v3-1-c8b924ffa5a2@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Diffstat (limited to 'drivers/hwspinlock/hwspinlock_core.c')
| -rw-r--r-- | drivers/hwspinlock/hwspinlock_core.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 0c0a932c00f3..6505261e6068 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -306,6 +306,34 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) EXPORT_SYMBOL_GPL(__hwspin_unlock); /** + * hwspin_lock_bust() - bust a specific hwspinlock + * @hwlock: a previously-acquired hwspinlock which we want to bust + * @id: identifier of the remote lock holder, if applicable + * + * This function will bust a hwspinlock that was previously acquired as + * long as the current owner of the lock matches the id given by the caller. + * + * Context: Process context. + * + * Returns: 0 on success, or -EINVAL if the hwspinlock does not exist, or + * the bust operation fails, and -EOPNOTSUPP if the bust operation is not + * defined for the hwspinlock. + */ +int hwspin_lock_bust(struct hwspinlock *hwlock, unsigned int id) +{ + if (WARN_ON(!hwlock)) + return -EINVAL; + + if (!hwlock->bank->ops->bust) { + pr_err("bust operation not defined\n"); + return -EOPNOTSUPP; + } + + return hwlock->bank->ops->bust(hwlock, id); +} +EXPORT_SYMBOL_GPL(hwspin_lock_bust); + +/** * of_hwspin_lock_simple_xlate - translate hwlock_spec to return a lock id * @hwlock_spec: hwlock specifier as found in the device tree * |