firmware: arm_scmi: Remove fixed size fields from reports/scmi_event_header

Event reports are used to convey information describing events to the
registered user-callbacks: they are necessarily derived from the underlying
raw SCMI events' messages but they are not meant to expose or directly
mirror any of those messages data layout, which belong to the protocol
layer.

Using fixed size types for report fields, mirroring messages structure,
is at odd with this: get rid of them using more generic, equivalent,
typing.

Substitute scmi_event_header fixed size fields with generic types too and
shuffle around fields definitions to minimize implicit padding while
adapting involved functions.

Link: https://lore.kernel.org/r/20200710133919.39792-3-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
index 752415367305..4731daaacd19 100644
--- a/drivers/firmware/arm_scmi/notify.c
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -80,6 +80,7 @@
 #include <linux/err.h>
 #include <linux/hashtable.h>
 #include <linux/kernel.h>
+#include <linux/ktime.h>
 #include <linux/kfifo.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
@@ -246,18 +247,18 @@ struct events_queue {
  * struct scmi_event_header  - A utility header
  * @timestamp: The timestamp, in nanoseconds (boottime), which was associated
  *	       to this event as soon as it entered the SCMI RX ISR
- * @evt_id: Event ID (corresponds to the Event MsgID for this Protocol)
  * @payld_sz: Effective size of the embedded message payload which follows
+ * @evt_id: Event ID (corresponds to the Event MsgID for this Protocol)
  * @payld: A reference to the embedded event payload
  *
  * This header is prepended to each received event message payload before
  * queueing it on the related &struct events_queue.
  */
 struct scmi_event_header {
-	u64	timestamp;
-	u8	evt_id;
-	size_t	payld_sz;
-	u8	payld[];
+	ktime_t timestamp;
+	size_t payld_sz;
+	unsigned char evt_id;
+	unsigned char payld[];
 };
 
 struct scmi_registered_event;
@@ -572,7 +573,7 @@ static void scmi_events_dispatcher(struct work_struct *work)
  * Return: 0 on Success
  */
 int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
-		const void *buf, size_t len, u64 ts)
+		const void *buf, size_t len, ktime_t ts)
 {
 	struct scmi_registered_event *r_evt;
 	struct scmi_event_header eh;
@@ -595,7 +596,7 @@ int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
 	if (kfifo_avail(&r_evt->proto->equeue.kfifo) < sizeof(eh) + len) {
 		dev_warn(handle->dev,
 			 "queue full, dropping proto_id:%d  evt_id:%d  ts:%lld\n",
-			 proto_id, evt_id, ts);
+			 proto_id, evt_id, ktime_to_ns(ts));
 		return -ENOMEM;
 	}