Revert "vgsp-sema: session boundary is a client change, not the last channel closing (ISSUE-0002)"

This reverts commit 12732c5894c893344422da4fd8d075c4c43c8e8a.

1 files changed, 10 insertions, 40 deletions

diff --git a/kernel/gsp_sema_service.c b/kernel/gsp_sema_service.c
index 9f967a5..638a866 100644
--- a/kernel/gsp_sema_service.c
+++ b/kernel/gsp_sema_service.c
@@ -451,11 +451,6 @@ static u32 svc_ring_n;
  */
 static u8 svc_sess_flush;
 static u8 svc_sess_active;	/* a channel of a session has registered (until flush) */
-static u32 svc_sess_client;	/* owning client of the current session's channels.
-				 * The kernel/GPU-global channels (the CeUtils
-				 * scrubber) persist across clients; the session
-				 * boundary is a change of owning client, not the
-				 * last channel closing (ISSUE-0002 r79). */
 static struct completion svc_sess_flush_done;	/* a pending flush has executed */
 static unsigned long svc_ring_done;	/* CE ranks whose ring is pinned (session state) */
 static u8 svc_pb_passes;
@@ -955,20 +950,6 @@ void gsp_sema_service_channel_add(const struct sema_channel_desc *desc)
 		WRITE_ONCE(svc_gr_content_rearm, true);
 
 	/*
-	 * ISSUE-0002 (r79): the kernel/GPU-global channels (the CeUtils
-	 * scrubber, entries=4096) persist across client sessions, so the
-	 * "last channel closed" trigger never fires once they are kept
-	 * registered. The real session boundary is a change of owning
-	 * client: when a channel of a new client registers while the
-	 * previous session's state is still live, request the same flush a
-	 * session end would (the wait below then lets svc_thread execute it
-	 * before this session's state exists).
-	 */
-	if (desc->h_client && svc_sess_client &&
-	    desc->h_client != svc_sess_client && svc_sess_active)
-		WRITE_ONCE(svc_sess_flush, 1);
-
-	/*
 	 * ISSUE-0002: a session-end flush may still be pending on svc_thread.
 	 * It must not execute after this session's state exists (r9: the
 	 * deferred flush ran between the first and second channel
@@ -1069,8 +1050,6 @@ void gsp_sema_service_channel_add(const struct sema_channel_desc *desc)
 		}
 		ch->valid = true;
 		svc_sess_active = 1;
-		if (desc->h_client)
-			svc_sess_client = desc->h_client;
 		ch->h_object = desc->h_object;
 		ch->h_client = desc->h_client;
 		ch->engine_type = desc->engine_type;
@@ -1157,28 +1136,19 @@ void gsp_sema_service_channel_del(u32 h_object, u32 h_client)
 		break;
 	}
 	/*
-	 * ISSUE-0002: when the last channel of the current session's client
-	 * closes, the next client is a new session in a new UVM VA space; its
-	 * discovery state must not inherit this session's map/pins/page-
-	 * directory latch. Request the flush here; it executes at the next
-	 * rebuild (the only writer of that state) just like a fresh boot
-	 * would start empty. Only the transition from "a session existed" to
-	 * "empty" may request it: redundant deletes for handles that never
-	 * registered would otherwise re-flush (and wipe) a session that
-	 * started after the real one ended. Persistent kernel/GPU-global
-	 * channels (a different owning client, e.g. the CeUtils scrubber) do
-	 * not keep the session open (ISSUE-0002 r79: with the scrubber kept
-	 * registered the old all-channels check never fired and the next
-	 * client inherited stale state).
+	 * ISSUE-0002: when the last channel closes, the next client is a new
+	 * session in a new UVM VA space; its discovery state must not inherit
+	 * this session's map/pins/page-directory latch. Request the flush
+	 * here; it executes at the next rebuild (the only writer of that
+	 * state) just like a fresh boot would start empty. Only the transition
+	 * from "a session existed" to "empty" may request it: redundant
+	 * deletes for handles that never registered would otherwise re-flush
+	 * (and wipe) a session that started after the real one ended.
 	 */
 	if (svc_sess_active) {
 		for (i = 0; i < SVC_MAX_CHANNELS; i++) {
-			if (!svc.chan[i].valid)
-				continue;
-			if (svc_sess_client && svc.chan[i].h_client &&
-			    svc.chan[i].h_client != svc_sess_client)
-				continue;
-			break;
+			if (svc.chan[i].valid)
+				break;
 		}
 		if (i == SVC_MAX_CHANNELS) {
 			svc_sess_active = 0;