diff --git a/sys/dev/firmware/arm/scmi.c b/sys/dev/firmware/arm/scmi.c
--- a/sys/dev/firmware/arm/scmi.c
+++ b/sys/dev/firmware/arm/scmi.c
@@ -43,6 +43,7 @@
 #include <sys/mutex.h>
 #include <sys/queue.h>
 #include <sys/refcount.h>
+#include <sys/sdt.h>
 #include <sys/taskqueue.h>
 
 #include <dev/clk/clk.h>
@@ -53,6 +54,26 @@
 #include "scmi.h"
 #include "scmi_protocols.h"
 
+SDT_PROVIDER_DEFINE(scmi);
+SDT_PROBE_DEFINE3(scmi, func, scmi_req_alloc, req_alloc,
+    "int", "int", "int");
+SDT_PROBE_DEFINE3(scmi, func, scmi_req_free_unlocked, req_alloc,
+    "int", "int", "int");
+SDT_PROBE_DEFINE3(scmi, func, scmi_req_get, req_alloc,
+    "int", "int", "int");
+SDT_PROBE_DEFINE3(scmi, func, scmi_req_put, req_alloc,
+    "int", "int", "int");
+SDT_PROBE_DEFINE5(scmi, func, scmi_request_tx, xfer_track,
+    "int", "int", "int", "int", "int");
+SDT_PROBE_DEFINE5(scmi, entry, scmi_wait_for_response, xfer_track,
+    "int", "int", "int", "int", "int");
+SDT_PROBE_DEFINE5(scmi, exit, scmi_wait_for_response, xfer_track,
+    "int", "int", "int", "int", "int");
+SDT_PROBE_DEFINE2(scmi, func, scmi_rx_irq_callback, hdr_dump,
+    "int", "int");
+SDT_PROBE_DEFINE5(scmi, func, scmi_process_response, xfer_track,
+    "int", "int", "int", "int", "int");
+
 #define SCMI_MAX_TOKEN		1024
 
 #define	SCMI_HDR_TOKEN_S		18
@@ -88,6 +109,12 @@
 
 #define SCMI_MSG_TOKEN(_hdr)		\
     (((_hdr) & SCMI_HDR_TOKEN_M) >> SCMI_HDR_TOKEN_S)
+#define SCMI_MSG_PROTOCOL_ID(_hdr)		\
+    (((_hdr) & SCMI_HDR_PROTOCOL_ID_M) >> SCMI_HDR_PROTOCOL_ID_S)
+#define SCMI_MSG_MESSAGE_ID(_hdr)		\
+    (((_hdr) & SCMI_HDR_MESSAGE_ID_M) >> SCMI_HDR_MESSAGE_ID_S)
+#define SCMI_MSG_TYPE(_hdr)		\
+    (((_hdr) & SCMI_HDR_TYPE_ID_M) >> SCMI_HDR_TYPE_ID_S)
 
 struct scmi_req {
 	int		cnt;
@@ -372,8 +399,11 @@
 	}
 	mtx_unlock_spin(&rp->mtx);
 
-	if (req != NULL)
+	if (req != NULL) {
 		refcount_init(&req->cnt, 1);
+		SDT_PROBE3(scmi, func, scmi_req_alloc, req_alloc,
+		    req, refcount_load(&req->cnt), -1);
+	}
 
 	return (req);
 }
@@ -392,6 +422,9 @@
 	refcount_init(&req->cnt, 0);
 	LIST_INSERT_HEAD(&rp->head, req, next);
 	mtx_unlock_spin(&rp->mtx);
+
+	SDT_PROBE3(scmi, func, scmi_req_free_unlocked, req_alloc,
+	    req, refcount_load(&req->cnt), -1);
 }
 
 static void
@@ -406,6 +439,9 @@
 	if (!ok)
 		device_printf(sc->dev, "%s() -- BAD REFCOUNT\n", __func__);
 
+	SDT_PROBE3(scmi, func, scmi_req_get, req_alloc,
+	    req, refcount_load(&req->cnt), SCMI_MSG_TOKEN(req->msg.hdr));
+
 	return;
 }
 
@@ -420,6 +456,9 @@
 		req->header = 0;
 		bzero(&req->msg, sizeof(req->msg) + SCMI_MAX_MSG_PAYLD_SIZE(sc));
 		scmi_req_free_unlocked(sc, SCMI_CHAN_A2P, req);
+	} else {
+		SDT_PROBE3(scmi, func, scmi_req_put, req_alloc,
+		    req, refcount_load(&req->cnt), SCMI_MSG_TOKEN(req->msg.hdr));
 	}
 	mtx_unlock_spin(&req->mtx);
 }
@@ -571,6 +610,10 @@
 		return;
 	}
 
+	SDT_PROBE5(scmi, func, scmi_process_response, xfer_track, req,
+	    SCMI_MSG_PROTOCOL_ID(req->msg.hdr), SCMI_MSG_MESSAGE_ID(req->msg.hdr),
+	    SCMI_MSG_TOKEN(req->msg.hdr), req->timed_out);
+
 	mtx_lock_spin(&req->mtx);
 	req->done = true;
 	req->msg.rx_len = rx_len;
@@ -608,6 +651,8 @@
 
 	sc = device_get_softc(dev);
 
+	SDT_PROBE2(scmi, func, scmi_rx_irq_callback, hdr_dump, hdr, rx_len);
+
 	if (SCMI_IS_MSG_TYPE_NOTIF(hdr) || SCMI_IS_MSG_TYPE_DRESP(hdr)) {
 		device_printf(dev, "DRESP/NOTIF unsupported. Drop.\n");
 		SCMI_CLEAR_CHANNEL(dev, chan);
@@ -623,6 +668,10 @@
 	unsigned int reply_timo_ms = SCMI_MAX_MSG_TIMEOUT_MS(sc);
 	int ret;
 
+	SDT_PROBE5(scmi, entry, scmi_wait_for_response, xfer_track, req,
+	    SCMI_MSG_PROTOCOL_ID(req->msg.hdr), SCMI_MSG_MESSAGE_ID(req->msg.hdr),
+	    SCMI_MSG_TOKEN(req->msg.hdr), reply_timo_ms);
+
 	if (req->msg.polling) {
 		bool needs_drop;
 
@@ -667,6 +716,10 @@
 
 	SCMI_TX_COMPLETE(sc->dev, NULL);
 
+	SDT_PROBE5(scmi, exit, scmi_wait_for_response, xfer_track, req,
+	    SCMI_MSG_PROTOCOL_ID(req->msg.hdr), SCMI_MSG_MESSAGE_ID(req->msg.hdr),
+	    SCMI_MSG_TOKEN(req->msg.hdr), req->timed_out);
+
 	return (ret);
 }
 
@@ -769,6 +822,10 @@
 		return (error);
 	}
 
+	SDT_PROBE5(scmi, func, scmi_request_tx, xfer_track, req,
+	    SCMI_MSG_PROTOCOL_ID(req->msg.hdr), SCMI_MSG_MESSAGE_ID(req->msg.hdr),
+	    SCMI_MSG_TOKEN(req->msg.hdr), req->msg.polling);
+
 	return (0);
 }