# HG changeset patch
# User Taylor R Campbell <riastradh@NetBSD.org>
# Date 1597974123 0
#      Fri Aug 21 01:42:03 2020 +0000
# Branch trunk
# Node ID bb8fb73dbefe6cafd7c2a64b30087ffad783f8c9
# Parent  d01cf28fde8015fc34a9724a9edc4f99c7035a8f
# EXP-Topic riastradh-mptfixes
mpt(4): Formalize request state transitions and make assertions.

diff -r d01cf28fde80 -r bb8fb73dbefe sys/dev/ic/mpt.c
--- a/sys/dev/ic/mpt.c	Thu Aug 20 19:43:42 2020 +0000
+++ b/sys/dev/ic/mpt.c	Fri Aug 21 01:42:03 2020 +0000
@@ -286,17 +286,33 @@ mpt_reset(mpt_softc_t *mpt)
 	return ret;
 }
 
+void
+mpt_transition_request(mpt_softc_t *mpt, request_t *req,
+    enum mpt_req_state ostate, enum mpt_req_state nstate)
+{
+
+	KASSERT(req);
+	KASSERTMSG(req == &mpt->request_pool[req->index],
+	    "request %u is %p, not %p",
+	    req->index, &mpt->request_pool[req->index], req);
+	KASSERTMSG(req->debug == ostate,
+	    "transition to %s -- request %p is in state %s, not %s",
+	    mpt_req_state(nstate),
+	    req,
+	    mpt_req_state(req->debug),
+	    mpt_req_state(ostate));
+
+	req->debug = nstate;
+}
+
 /* Return a command buffer to the free queue */
 void
 mpt_free_request(mpt_softc_t *mpt, request_t *req)
 {
-	if (req == NULL || req != &mpt->request_pool[req->index]) {
-		panic("mpt_free_request bad req ptr\n");
-		return;
-	}
+
+	mpt_transition_request(mpt, req, REQ_DONE, REQ_FREE);
 	req->sequence = 0;
 	req->xfer = NULL;
-	req->debug = REQ_FREE;
 	SLIST_INSERT_HEAD(&mpt->request_free_list, req, link);
 }
 
@@ -305,17 +321,13 @@ request_t *
 mpt_get_request(mpt_softc_t *mpt)
 {
 	request_t *req;
+
 	req = SLIST_FIRST(&mpt->request_free_list);
-	if (req != NULL) {
-		if (req != &mpt->request_pool[req->index]) {
-			panic("mpt_get_request: corrupted request free list\n");
-		}
-		if (req->xfer != NULL) {
-			panic("mpt_get_request: corrupted request free list (xfer)\n");
-		}
-		SLIST_REMOVE_HEAD(&mpt->request_free_list, link);
-		req->debug = REQ_IN_PROGRESS;
-	}
+	if (req == NULL)
+		return NULL;
+
+	mpt_transition_request(mpt, req, REQ_FREE, REQ_IN_PROGRESS);
+	SLIST_REMOVE_HEAD(&mpt->request_free_list, link);
 	return req;
 }
 
@@ -323,6 +335,8 @@ mpt_get_request(mpt_softc_t *mpt)
 void
 mpt_send_cmd(mpt_softc_t *mpt, request_t *req)
 {
+
+	mpt_transition_request(mpt, req, REQ_IN_PROGRESS, REQ_ON_CHIP);
 	req->sequence = mpt->sequence++;
 	if (mpt->verbose > 1) {
 		u_int32_t *pReq;
@@ -339,7 +353,6 @@ mpt_send_cmd(mpt_softc_t *mpt, request_t
 		    pReq[12], pReq[13], pReq[14], pReq[15]);
 	}
 	MPT_SYNC_REQ(mpt, req, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
-	req->debug = REQ_ON_CHIP;
 	mpt_write(mpt, MPT_OFFSET_REQUEST_Q, (u_int32_t) req->req_pbuf);
 }
 
diff -r d01cf28fde80 -r bb8fb73dbefe sys/dev/ic/mpt.h
--- a/sys/dev/ic/mpt.h	Thu Aug 20 19:43:42 2020 +0000
+++ b/sys/dev/ic/mpt.h	Fri Aug 21 01:42:03 2020 +0000
@@ -168,6 +168,8 @@ int mpt_hw_init(mpt_softc_t *);
 int mpt_init(mpt_softc_t *, u_int32_t);
 int mpt_reset(mpt_softc_t *);
 int mpt_send_handshake_cmd(mpt_softc_t *, size_t, void *);
+void mpt_transition_request(mpt_softc_t *, request_t *, enum mpt_req_state,
+    enum mpt_req_state);
 request_t * mpt_get_request(mpt_softc_t *);
 void mpt_free_request(mpt_softc_t *, request_t *);
 int mpt_intr(void *);
diff -r d01cf28fde80 -r bb8fb73dbefe sys/dev/ic/mpt_netbsd.c
--- a/sys/dev/ic/mpt_netbsd.c	Thu Aug 20 19:43:42 2020 +0000
+++ b/sys/dev/ic/mpt_netbsd.c	Fri Aug 21 01:42:03 2020 +0000
@@ -1288,7 +1288,13 @@ mpt_ctlop(mpt_softc_t *mpt, void *vmsg, 
 			mpt_prt(mpt, "enable port reply index %d", index);
 		if (index >= 0 && index < MPT_MAX_REQUESTS(mpt)) {
 			request_t *req = &mpt->request_pool[index];
-			req->debug = REQ_DONE;
+			if (req->debug != REQ_ON_CHIP) {
+				mpt_prt(mpt, "bogus port reply %d (%s)",
+				    req->index, mpt_req_state(req->debug));
+			} else {
+				mpt_transition_request(mpt, req, REQ_ON_CHIP,
+				    REQ_DONE);
+			}
 		}
 		mpt_free_reply(mpt, (reply << 1));
 		break;
@@ -1300,8 +1306,14 @@ mpt_ctlop(mpt_softc_t *mpt, void *vmsg, 
 		int index = le32toh(msg->MsgContext) & ~0x80000000;
 		if (index >= 0 && index < MPT_MAX_REQUESTS(mpt)) {
 			request_t *req = &mpt->request_pool[index];
-			req->debug = REQ_DONE;
-			req->sequence = reply;
+			if (req->debug != REQ_ON_CHIP) {
+				mpt_prt(mpt, "bogus config reply %d (%s)",
+				    req->index, mpt_req_state(req->debug));
+			} else {
+				mpt_transition_request(mpt, req, REQ_ON_CHIP,
+				    REQ_DONE);
+				req->sequence = reply;
+			}
 		} else
 			mpt_free_reply(mpt, (reply << 1));
 		break;