smcinvoke: update process_tzcb_req to be more responsive

1. While waiting for callback response instead of waiting uninterruptibly for
  1sec split wait timeout to 100ms and increase number of retries to 50.

2. If a wait is interrupted due to signal, continue to wait if callback server
   is in a good state.

Change-Id: I15faf27ebdb98e2df4a0c75695643a611ad9889d

smcinvoke/smcinvoke.c

@@ -59,7 +59,6 @@
 #define SMCINVOKE_SCM_EBUSY_MAX_RETRY		200
 
 
-
 /* TZ defined values - Start */
 #define SMCINVOKE_INVOKE_PARAM_ID		0x224
 #define SMCINVOKE_CB_RSP_PARAM_ID		0x22
@@ -75,7 +74,7 @@
  */
 #define SMCINVOKE_SERVER_STATE_DEFUNCT		1
 
-#define CBOBJ_MAX_RETRIES 5
+#define CBOBJ_MAX_RETRIES 50
 #define FOR_ARGS(ndxvar, counts, section) \
 	for (ndxvar = OBJECT_COUNTS_INDEX_##section(counts); \
 		ndxvar < (OBJECT_COUNTS_INDEX_##section(counts) \
@@ -1377,6 +1376,7 @@ static void process_tzcb_req(void *buf, size_t buf_len, struct file **arr_filp)
 	int ret = OBJECT_ERROR_DEFUNCT;
 	int cbobj_retries = 0;
 	long timeout_jiff;
+	bool wait_interrupted = false;
 	struct smcinvoke_cb_txn *cb_txn = NULL;
 	struct smcinvoke_tzcb_req *cb_req = NULL, *tmp_cb_req = NULL;
 	struct smcinvoke_server_info *srvr_info = NULL;
@@ -1461,14 +1461,20 @@ static void process_tzcb_req(void *buf, size_t buf_len, struct file **arr_filp)
 	 */
 	wake_up_interruptible_all(&srvr_info->req_wait_q);
 	/* timeout before 1s otherwise tzbusy would come */
-	timeout_jiff = msecs_to_jiffies(1000);
+	timeout_jiff = msecs_to_jiffies(100);
 
 	while (cbobj_retries < CBOBJ_MAX_RETRIES) {
-		ret = wait_event_timeout(srvr_info->rsp_wait_q,
-				(cb_txn->state == SMCINVOKE_REQ_PROCESSED) ||
-				(srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT),
-				timeout_jiff);
-
+		if (wait_interrupted) {
+			ret = wait_event_timeout(srvr_info->rsp_wait_q,
+					(cb_txn->state == SMCINVOKE_REQ_PROCESSED) ||
+					(srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT),
+					timeout_jiff);
+		} else {
+			ret = wait_event_interruptible_timeout(srvr_info->rsp_wait_q,
+					(cb_txn->state == SMCINVOKE_REQ_PROCESSED) ||
+					(srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT),
+					timeout_jiff);
+		}
 		if (ret == 0) {
 			pr_err("CBobj timed out cb-tzhandle:%d, retry:%d, op:%d counts :%d\n",
 					cb_req->hdr.tzhandle, cbobj_retries,
@@ -1478,7 +1484,13 @@ static void process_tzcb_req(void *buf, size_t buf_len, struct file **arr_filp)
 					current->tgid, srvr_info->state,
 					srvr_info->server_id);
 		} else {
-			break;
+			/* wait_event returned due to a signal */
+			if (srvr_info->state != SMCINVOKE_SERVER_STATE_DEFUNCT &&
+					cb_txn->state != SMCINVOKE_REQ_PROCESSED) {
+				wait_interrupted = true;
+			} else {
+				break;
+			}
 		}
 		cbobj_retries++;
 	}