Currently the mutex dedicated to the protection of the list of registered protocols is held during all the protocol initialization phase. Such a wide locking region is not needed and causes problem when trying to initialize notifications from within a protocol initialization routine. Reduce the scope of the protocol mutex. Signed-off-by: Cristian Marussi --- v1-->v2 - Fixed improper mixed usage of cleanup and goto constructs --- drivers/firmware/arm_scmi/driver.c | 50 ++++++++++++++---------------- 1 file changed, 24 insertions(+), 26 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 7e5429eff35d..b198c58da1dd 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -17,6 +17,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -2123,7 +2124,6 @@ static int scmi_protocol_version_negotiate(struct scmi_protocol_handle *ph) * all resources management is handled via a dedicated per-protocol devres * group. * - * Context: Assumes to be called with @protocols_mtx already acquired. * Return: A reference to a freshly allocated and initialized protocol instance * or ERR_PTR on failure. On failure the @proto reference is at first * put using @scmi_protocol_put() before releasing all the devres group. @@ -2162,8 +2162,10 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, if (ret) goto clean; - ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1, - GFP_KERNEL); + /* Finally register the initialized protocol */ + mutex_lock(&info->protocols_mtx); + ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1, GFP_KERNEL); + mutex_unlock(&info->protocols_mtx); if (ret != proto->id) goto clean; @@ -2226,27 +2228,25 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, static struct scmi_protocol_instance * __must_check scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id) { - struct scmi_protocol_instance *pi; struct scmi_info *info = handle_to_scmi_info(handle); + const struct scmi_protocol *proto; - mutex_lock(&info->protocols_mtx); - pi = idr_find(&info->protocols, protocol_id); - - if (pi) { - refcount_inc(&pi->users); - } else { - const struct scmi_protocol *proto; + scoped_guard(mutex, &info->protocols_mtx) { + struct scmi_protocol_instance *pi; - /* Fails if protocol not registered on bus */ - proto = scmi_protocol_get(protocol_id, &info->version); - if (proto) - pi = scmi_alloc_init_protocol_instance(info, proto); - else - pi = ERR_PTR(-EPROBE_DEFER); + pi = idr_find(&info->protocols, protocol_id); + if (pi) { + refcount_inc(&pi->users); + return pi; + } } - mutex_unlock(&info->protocols_mtx); - return pi; + /* Fails if protocol not registered on bus */ + proto = scmi_protocol_get(protocol_id, &info->version); + if (!proto) + return ERR_PTR(-EPROBE_DEFER); + + return scmi_alloc_init_protocol_instance(info, proto); } /** @@ -2277,10 +2277,11 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) struct scmi_info *info = handle_to_scmi_info(handle); struct scmi_protocol_instance *pi; - mutex_lock(&info->protocols_mtx); - pi = idr_find(&info->protocols, protocol_id); - if (WARN_ON(!pi)) - goto out; + scoped_guard(mutex, &info->protocols_mtx) { + pi = idr_find(&info->protocols, protocol_id); + if (WARN_ON(!pi)) + return; + } if (refcount_dec_and_test(&pi->users)) { void *gid = pi->gid; @@ -2299,9 +2300,6 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n", protocol_id); } - -out: - mutex_unlock(&info->protocols_mtx); } void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, -- 2.52.0