[PATCH v4 04/13] firmware: arm_scmi: Add support for notifications message processing

Cristian Marussi
2020-03-04T16:27:20Z

From: Sudeep Holla <sudeep.holla@arm.com>

Add the mechanisms to distinguish notifications from delayed responses and
to properly fetch notification messages upon reception: notifications
processing does not continue further after the fetch phase.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
[Reworked/renamed scmi_handle_xfer_delayed_resp()]
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
V1 --> V2
- switch the notif/delayed_resp message processing logic to use new
transport independent layer methods
- reviewed logic of scmi_handle_xfer_delayed_resp() while renaming it as
scmi_handle_response()
- properly relocated tracer points
---
drivers/firmware/arm_scmi/driver.c | 84 +++++++++++++++++++++++-------
1 file changed, 64 insertions(+), 20 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index efb660c34b57..868cc36a07c9 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -202,29 +202,42 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
}

-/**
- * scmi_rx_callback() - callback for receiving messages
- *
- * @cinfo: SCMI channel info
- * @msg_hdr: Message header
- *
- * Processes one received message to appropriate transfer information and
- * signals completion of the transfer.
- *
- * NOTE: This function will be invoked in IRQ context, hence should be
- * as optimal as possible.
- */
-void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr)
+static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
{
- struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
- struct scmi_xfers_info *minfo = &info->tx_minfo;
- u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr);
- u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
- struct device *dev = cinfo->dev;
struct scmi_xfer *xfer;
+ struct device *dev = cinfo->dev;
+ struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
+ struct scmi_xfers_info *minfo = &info->rx_minfo;
+
+ xfer = scmi_xfer_get(cinfo->handle, minfo);
+ if (IS_ERR(xfer)) {
+ dev_err(dev, "failed to get free message slot (%ld)\n",
+ PTR_ERR(xfer));
+ info->desc->ops->clear_notification(cinfo);
+ return;
+ }
+
+ unpack_scmi_header(msg_hdr, &xfer->hdr);
+ scmi_dump_header_dbg(dev, &xfer->hdr);
+ info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size,
+ xfer);
+
+ trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id,
+ xfer->hdr.protocol_id, xfer->hdr.seq,
+ MSG_TYPE_NOTIFICATION);

- if (msg_type == MSG_TYPE_NOTIFICATION)
- return; /* Notifications not yet supported */
+ __scmi_xfer_put(minfo, xfer);
+
+ info->desc->ops->clear_notification(cinfo);
+}
+
+static void scmi_handle_response(struct scmi_chan_info *cinfo,
+ u16 xfer_id, u8 msg_type)
+{
+ struct scmi_xfer *xfer;
+ struct device *dev = cinfo->dev;
+ struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
+ struct scmi_xfers_info *minfo = &info->tx_minfo;

/* Are we even expecting this? */
if (!test_bit(xfer_id, minfo->xfer_alloc_table)) {
@@ -248,6 +261,37 @@ void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr)
complete(&xfer->done);
}

+/**
+ * scmi_rx_callback() - callback for receiving messages
+ *
+ * @cinfo: SCMI channel info
+ * @msg_hdr: Message header
+ *
+ * Processes one received message to appropriate transfer information and
+ * signals completion of the transfer.
+ *
+ * NOTE: This function will be invoked in IRQ context, hence should be
+ * as optimal as possible.
+ */
+void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr)
+{
+ u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr);
+ u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
+
+ switch (msg_type) {
+ case MSG_TYPE_NOTIFICATION:
+ scmi_handle_notification(cinfo, msg_hdr);
+ break;
+ case MSG_TYPE_COMMAND:
+ case MSG_TYPE_DELAYED_RESP:
+ scmi_handle_response(cinfo, xfer_id, msg_type);
+ break;
+ default:
+ WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type);
+ break;
+ }
+}
+
/**
* scmi_xfer_put() - Release a transmit message
*
--
2.17.1