[PATCH 1/2] firmware: arm_scmi: Ensure that the message-id supports fastchannel

[Sibi Sankar]

Currently the perf and powercap protocol relies on the protocol domain
attributes, which just ensures that one fastchannel per domain, before
instantiating fastchannels for all possible message-ids. Fix this by
ensuring that each message-id supports fastchannel before initialization.

Fixes: 6f9ea4dabd2d ("firmware: arm_scmi: Generalize the fast channel support")
Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
---
 drivers/firmware/arm_scmi/driver.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 69c15135371c..95d039152f79 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -56,6 +56,9 @@ static atomic_t transfer_last_id;
 
 static struct dentry *scmi_top_dentry;
 
+static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph,
+				   u32 message_id, u32 *attributes);
+
 /**
  * struct scmi_xfers_info - Structure to manage transfer information
  *
@@ -1841,6 +1844,7 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph,
 	int ret;
 	u32 flags;
 	u64 phys_addr;
+	u32 attributes;
 	u8 size;
 	void __iomem *addr;
 	struct scmi_xfer *t;
@@ -1849,6 +1853,11 @@ scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph,
 	struct scmi_msg_resp_desc_fc *resp;
 	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
 
+	/* Check if the MSG_ID supports fastchannel */
+	ret = scmi_protocol_msg_check(ph, message_id, &attributes);
+	if (!ret && !MSG_SUPPORTS_FASTCHANNEL(attributes))
+		return;
+
 	if (!p_addr) {
 		ret = -EINVAL;
 		goto err_out;
-- 
2.34.1