[RFC PATCH v2 5/8] firmware: arm_scmi: Add is_transport_atomic() handle method

From: Cristian Marussi
Date: Mon Jul 05 2021 - 13:10:55 EST


Add a method to check if the underlying transport configured for an SCMI
instance is configured to support atomic transaction of SCMI commands.

Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
drivers/firmware/arm_scmi/driver.c | 16 ++++++++++++++++
include/linux/scmi_protocol.h | 8 ++++++++
2 files changed, 24 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 43aff6b26571..22173f747fdb 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1558,6 +1558,21 @@ static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id)
WARN_ON(ret);
}

+/**
+ * scmi_is_transport_atomic - Method to check if underlying transport for an
+ * SCMI instance is configured as atomic.
+ *
+ * @handle: A reference to the SCMI platform instance.
+ *
+ * Return: True if transport is configured as atomic
+ */
+static bool scmi_is_transport_atomic(const struct scmi_handle *handle)
+{
+ struct scmi_info *info = handle_to_scmi_info(handle);
+
+ return info->desc->atomic_capable;
+}
+
static inline
struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info)
{
@@ -2074,6 +2089,7 @@ static int scmi_probe(struct platform_device *pdev)
handle->version = &info->version;
handle->devm_protocol_get = scmi_devm_protocol_get;
handle->devm_protocol_put = scmi_devm_protocol_put;
+ handle->is_transport_atomic = scmi_is_transport_atomic;

if (desc->ops->link_supplier) {
ret = desc->ops->link_supplier(dev);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 79d0a1237e6c..b28eb7c104e7 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -608,6 +608,13 @@ struct scmi_notify_ops {
* @devm_protocol_get: devres managed method to acquire a protocol and get specific
* operations and a dedicated protocol handler
* @devm_protocol_put: devres managed method to release a protocol
+ * @is_transport_atomic: method to check if the underlying transport for this
+ * instance handle is configured to support atomic
+ * transactions for commands.
+ * Some users of the SCMI stack in the upper layers could
+ * be interested to know if they can assume SCMI
+ * command transactions associated to this handle will
+ * never sleep and act accordingly.
* @notify_ops: pointer to set of notifications related operations
*/
struct scmi_handle {
@@ -618,6 +625,7 @@ struct scmi_handle {
(*devm_protocol_get)(struct scmi_device *sdev, u8 proto,
struct scmi_protocol_handle **ph);
void (*devm_protocol_put)(struct scmi_device *sdev, u8 proto);
+ bool (*is_transport_atomic)(const struct scmi_handle *handle);

const struct scmi_notify_ops *notify_ops;
};
--
2.17.1