firmware: arm_scmi: Add priv parameter to scmi_rx_callback

Add a new opaque void *priv parameter to scmi_rx_callback which can be
optionally provided by the transport layer when invoking scmi_rx_callback
and that will be passed back to the transport layer in xfer->priv.

This can be used by transports that needs to keep track of their specific
data structures together with the valid xfers.

Link: https://lore.kernel.org/r/20210803131024.40280-15-cristian.marussi@arm.comSigned-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

drivers/firmware/arm_scmi/common.h

@@ -172,6 +172,7 @@ struct scmi_msg {
  *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK
  *	      (Missing synchronous response is assumed OK and ignored)
  * @lock: A spinlock to protect state and busy fields.
+ * @priv: A pointer for transport private usage.
  */
 struct scmi_xfer {
 	int transfer_id;
@@ -192,6 +193,7 @@ struct scmi_xfer {
 	int state;
 	/* A lock to protect state and busy fields */
 	spinlock_t lock;
+	void *priv;
 };
 
 /*
@@ -417,7 +419,7 @@ extern const struct scmi_desc scmi_mailbox_desc;
 extern const struct scmi_desc scmi_smc_desc;
 #endif
 
-void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);
+void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
 void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
 
 /* shmem related declarations */

drivers/firmware/arm_scmi/driver.c

@@ -609,7 +609,8 @@ static inline void scmi_clear_channel(struct scmi_info *info,
 		info->desc->ops->clear_channel(cinfo);
 }
 
-static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
+static void scmi_handle_notification(struct scmi_chan_info *cinfo,
+				     u32 msg_hdr, void *priv)
 {
 	struct scmi_xfer *xfer;
 	struct device *dev = cinfo->dev;
@@ -627,6 +628,8 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
 	}
 
 	unpack_scmi_header(msg_hdr, &xfer->hdr);
+	if (priv)
+		xfer->priv = priv;
 	info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size,
 					    xfer);
 	scmi_notify(cinfo->handle, xfer->hdr.protocol_id,
@@ -641,7 +644,8 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr)
 	scmi_clear_channel(info, cinfo);
 }
 
-static void scmi_handle_response(struct scmi_chan_info *cinfo, u32 msg_hdr)
+static void scmi_handle_response(struct scmi_chan_info *cinfo,
+				 u32 msg_hdr, void *priv)
 {
 	struct scmi_xfer *xfer;
 	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
@@ -656,6 +660,8 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, u32 msg_hdr)
 	if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP)
 		xfer->rx.len = info->desc->max_msg_size;
 
+	if (priv)
+		xfer->priv = priv;
 	info->desc->ops->fetch_response(cinfo, xfer);
 
 	trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id,
@@ -677,6 +683,7 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, u32 msg_hdr)
  *
  * @cinfo: SCMI channel info
  * @msg_hdr: Message header
+ * @priv: Transport specific private data.
  *
  * Processes one received message to appropriate transfer information and
  * signals completion of the transfer.
@@ -684,17 +691,17 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, u32 msg_hdr)
  * 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)
+void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv)
 {
 	u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
 
 	switch (msg_type) {
 	case MSG_TYPE_NOTIFICATION:
-		scmi_handle_notification(cinfo, msg_hdr);
+		scmi_handle_notification(cinfo, msg_hdr, priv);
 		break;
 	case MSG_TYPE_COMMAND:
 	case MSG_TYPE_DELAYED_RESP:
-		scmi_handle_response(cinfo, msg_hdr);
+		scmi_handle_response(cinfo, msg_hdr, priv);
 		break;
 	default:
 		WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type);

drivers/firmware/arm_scmi/mailbox.c

@@ -43,7 +43,7 @@ static void rx_callback(struct mbox_client *cl, void *m)
 {
 	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
 
-	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem));
+	scmi_rx_callback(smbox->cinfo, shmem_read_header(smbox->shmem), NULL);
 }
 
 static bool mailbox_chan_available(struct device *dev, int idx)

drivers/firmware/arm_scmi/smc.c

@@ -154,7 +154,8 @@ static int smc_send_message(struct scmi_chan_info *cinfo,
 	if (scmi_info->irq)
 		wait_for_completion(&scmi_info->tx_complete);
 
-	scmi_rx_callback(scmi_info->cinfo, shmem_read_header(scmi_info->shmem));
+	scmi_rx_callback(scmi_info->cinfo,
+			 shmem_read_header(scmi_info->shmem), NULL);
 
 	mutex_unlock(&scmi_info->shmem_lock);