qcacmn: Fix lock issues with object manager

1) Implement lock free API for get peer
   In DA UAPSD, get_peer API is invoked in ISR context, This is causing
   system to get into deadlock, since the current get_peer() gets preempted
   Lock acquire attempt is done in ISR context

2) Avoid invoking peer_release_ref() calls with peer_list_lock() acquired
   as peer_release_ref can invoke peer destroy operation

Change-Id: I095ae12ced4201cdc68bda70c8e8dee6cfb2bb9d
CRs-Fixed: 2028529

umac/cmn_services/obj_mgr/inc/wlan_objmgr_psoc_obj.h

@@ -458,6 +458,21 @@ struct wlan_objmgr_peer *wlan_objmgr_get_peer(
 			struct wlan_objmgr_psoc *psoc, uint8_t *macaddr,
 			wlan_objmgr_ref_dbgid dbg_id);
 
+/**
+ * wlan_objmgr_get_peer_nolock() - find peer from psoc's peer list (lock free)
+ * @psoc: PSOC object
+ * @macaddr: MAC address
+ * @dbg_id: id of the caller
+ *
+ * API to find peer object pointer by MAC addr
+ *
+ * Return: peer pointer
+ *         NULL on FAILURE
+ */
+struct wlan_objmgr_peer *wlan_objmgr_get_peer_nolock(
+			struct wlan_objmgr_psoc *psoc, uint8_t *macaddr,
+			wlan_objmgr_ref_dbgid dbg_id);
+
 /**
  * wlan_objmgr_get_peer_logically_deleted() - find peer
  * from psoc's peer list

umac/cmn_services/obj_mgr/src/wlan_objmgr_psoc_obj.c

@@ -951,19 +951,21 @@ static struct wlan_objmgr_peer *
 	/* Iterate through hash list to get the peer */
 	peer = wlan_psoc_peer_list_peek_head(obj_list);
 	while (peer != NULL) {
-		wlan_objmgr_peer_get_ref(peer, dbg_id);
 		/* For peer, macaddr is key */
 		if (WLAN_ADDR_EQ(wlan_peer_get_macaddr(peer), macaddr)
 			== QDF_STATUS_SUCCESS) {
 			/* Return peer in logically deleted state */
-			if (peer->obj_state == WLAN_OBJ_STATE_LOGICALLY_DELETED)
+			if (peer->obj_state ==
+					WLAN_OBJ_STATE_LOGICALLY_DELETED) {
+				wlan_objmgr_peer_get_ref(peer, dbg_id);
+
 				return peer;
+			}
 
 		}
 		/* Move to next peer */
 		peer_temp = peer;
 		peer = wlan_peer_get_next_peer_of_psoc(obj_list, peer_temp);
-		wlan_objmgr_peer_release_ref(peer_temp, dbg_id);
 	}
 
 	/* Not found, return NULL */
@@ -1061,7 +1063,6 @@ static struct wlan_objmgr_peer
 	/* Iterate through hash list to get the peer */
 	peer = wlan_psoc_peer_list_peek_head(obj_list);
 	while (peer != NULL) {
-		wlan_objmgr_peer_get_ref(peer, dbg_id);
 		/* For peer, macaddr is key */
 		if (WLAN_ADDR_EQ(wlan_peer_get_macaddr(peer), macaddr)
 			== QDF_STATUS_SUCCESS) {
@@ -1074,14 +1075,16 @@ static struct wlan_objmgr_peer
 							QDF_STATUS_SUCCESS) {
 				/* Return peer in logically deleted state */
 				if (peer->obj_state ==
-					WLAN_OBJ_STATE_LOGICALLY_DELETED)
+					WLAN_OBJ_STATE_LOGICALLY_DELETED) {
+					wlan_objmgr_peer_get_ref(peer, dbg_id);
+
 					return peer;
+				}
 			}
 		}
 		/* Move to next peer */
 		peer_temp = peer;
 		peer = wlan_peer_get_next_peer_of_psoc(obj_list, peer_temp);
-		wlan_objmgr_peer_release_ref(peer_temp, dbg_id);
 	}
 
 	/* Not found, return NULL */
@@ -1113,7 +1116,6 @@ static struct wlan_objmgr_peer *wlan_obj_psoc_peerlist_get_peer_by_mac_n_bssid(
 	/* Iterate through hash list to get the peer */
 	peer = wlan_psoc_peer_list_peek_head(obj_list);
 	while (peer != NULL) {
-		wlan_objmgr_peer_get_ref(peer, dbg_id);
 		/* For peer, macaddr is key */
 		if (WLAN_ADDR_EQ(wlan_peer_get_macaddr(peer), macaddr)
 			== QDF_STATUS_SUCCESS) {
@@ -1124,26 +1126,16 @@ static struct wlan_objmgr_peer *wlan_obj_psoc_peerlist_get_peer_by_mac_n_bssid(
 			 */
 			if (wlan_peer_bssid_match(peer, bssid) ==
 							QDF_STATUS_SUCCESS) {
-				/*
-				 * Release ref, and return NULL, if peer state
-				 * is logically deleted
-				 */
-				if (peer->obj_state ==
-					WLAN_OBJ_STATE_LOGICALLY_DELETED) {
-					wlan_objmgr_peer_release_ref(peer,
-									dbg_id);
-					peer = NULL;
+				if (wlan_objmgr_peer_try_get_ref(peer, dbg_id)
+					== QDF_STATUS_SUCCESS) {
+					return peer;
 				}
-
-				return peer;
 			}
 		}
 		/* Move to next peer */
 		peer_temp = peer;
 		peer = wlan_peer_get_next_peer_of_psoc(obj_list, peer_temp);
-		wlan_objmgr_peer_release_ref(peer_temp, dbg_id);
 	}
-
 	/* Not found, return NULL */
 	return NULL;
 }
@@ -1281,6 +1273,7 @@ struct wlan_objmgr_peer *wlan_objmgr_get_peer_logically_deleted(
 
 	return peer;
 }
+
 struct wlan_objmgr_peer *wlan_objmgr_get_peer(
 			struct wlan_objmgr_psoc *psoc, uint8_t *macaddr,
 			wlan_objmgr_ref_dbgid dbg_id)
@@ -1312,6 +1305,33 @@ struct wlan_objmgr_peer *wlan_objmgr_get_peer(
 }
 EXPORT_SYMBOL(wlan_objmgr_get_peer);
 
+struct wlan_objmgr_peer *wlan_objmgr_get_peer_nolock(
+			struct wlan_objmgr_psoc *psoc, uint8_t *macaddr,
+			wlan_objmgr_ref_dbgid dbg_id)
+{
+	struct wlan_objmgr_psoc_objmgr *objmgr;
+	uint8_t hash_index;
+	struct wlan_objmgr_peer *peer = NULL;
+	struct wlan_peer_list *peer_list;
+
+	/* psoc lock should be taken before peer list lock */
+	objmgr = &psoc->soc_objmgr;
+	/* List is empty, return NULL */
+	if (objmgr->wlan_peer_count == 0)
+		return NULL;
+
+	/* reduce the search window, with hash key */
+	hash_index = WLAN_PEER_HASH(macaddr);
+	peer_list = &objmgr->peer_list;
+	/* Iterate through peer list, get peer */
+	peer = wlan_obj_psoc_peerlist_get_peer(
+		&peer_list->peer_hash[hash_index], macaddr, dbg_id);
+
+	return peer;
+}
+EXPORT_SYMBOL(wlan_objmgr_get_peer_nolock);
+
+
 struct wlan_objmgr_peer *wlan_objmgr_get_peer_no_state(
 			struct wlan_objmgr_psoc *psoc, uint8_t *macaddr,
 			wlan_objmgr_ref_dbgid dbg_id)