hwspinlock: qcom: implement bust operation

Implement a new operation qcom_hwspinlock_bust() which can be invoked
to bust any locks that are in use when a remoteproc is stopped or
crashed.

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-v3-2-c8b924ffa5a2@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c
index 814dfe8697bf3603f2707f5d5d69430876d72679..0390979fd765d0fa9b0d2d6c1071f3562edf2b76 100644 (file)
--- a/drivers/hwspinlock/qcom_hwspinlock.c
+++ b/drivers/hwspinlock/qcom_hwspinlock.c
@@ -64,9 +64,34 @@ static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
                pr_err("%s: failed to unlock spinlock\n", __func__);
 }
 
+static int qcom_hwspinlock_bust(struct hwspinlock *lock, unsigned int id)
+{
+       struct regmap_field *field = lock->priv;
+       u32 owner;
+       int ret;
+
+       ret = regmap_field_read(field, &owner);
+       if (ret) {
+               dev_err(lock->bank->dev, "unable to query spinlock owner\n");
+               return ret;
+       }
+
+       if (owner != id)
+               return 0;
+
+       ret = regmap_field_write(field, 0);
+       if (ret) {
+               dev_err(lock->bank->dev, "failed to bust spinlock\n");
+               return ret;
+       }
+
+       return 0;
+}
+
 static const struct hwspinlock_ops qcom_hwspinlock_ops = {
        .trylock        = qcom_hwspinlock_trylock,
        .unlock         = qcom_hwspinlock_unlock,
+       .bust           = qcom_hwspinlock_bust,
 };
 
 static const struct regmap_config sfpb_mutex_config = {