staging: vc04_services: Drop VCHIQ_RETRY usage

Drop the usage of VCHIQ_RETRY vchiq_status enum type in most of the
places and replace it with -EAGAIN. The exception to this replacement
is vchiq_send_remote_use() and vchiq_send_remote_use_active() which will
be addressed in the subsequent commit.

This patch acts as intermediatory to address the TODO item:
    * Get rid of custom function return values
for vc04_services/interface.
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20221223122404.170585-5-umang.jain@ideasonboard.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -728,7 +728,7 @@ int vchiq_shutdown(struct vchiq_instance *instance)
 	struct vchiq_state *state = instance->state;
 
 	if (mutex_lock_killable(&state->mutex))
-		return VCHIQ_RETRY;
+		return -EAGAIN;
 
 	/* Remove all services */
 	vchiq_shutdown_internal(state, instance);
@@ -756,7 +756,7 @@ int vchiq_connect(struct vchiq_instance *instance)
 
 	if (mutex_lock_killable(&state->mutex)) {
 		vchiq_log_trace(vchiq_core_log_level, "%s: call to mutex_lock failed", __func__);
-		status = VCHIQ_RETRY;
+		status = -EAGAIN;
 		goto failed;
 	}
 	status = vchiq_connect_internal(state, instance);
@@ -859,11 +859,11 @@ vchiq_bulk_transmit(struct vchiq_instance *instance, unsigned int handle, const
 		}
 
 		/*
-		 * vchiq_*_bulk_transfer() may return VCHIQ_RETRY, so we need
+		 * vchiq_*_bulk_transfer() may return -EAGAIN, so we need
 		 * to implement a retry mechanism since this function is
 		 * supposed to block until queued
 		 */
-		if (status != VCHIQ_RETRY)
+		if (status != -EAGAIN)
 			break;
 
 		msleep(1);
@@ -896,11 +896,11 @@ int vchiq_bulk_receive(struct vchiq_instance *instance, unsigned int handle,
 		}
 
 		/*
-		 * vchiq_*_bulk_transfer() may return VCHIQ_RETRY, so we need
+		 * vchiq_*_bulk_transfer() may return -EAGAIN, so we need
 		 * to implement a retry mechanism since this function is
 		 * supposed to block until queued
 		 */
-		if (status != VCHIQ_RETRY)
+		if (status != -EAGAIN)
 			break;
 
 		msleep(1);
@@ -961,7 +961,7 @@ vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handl
 	status = vchiq_bulk_transfer(instance, handle, data, NULL, size,
 				     &waiter->bulk_waiter,
 				     VCHIQ_BULK_MODE_BLOCKING, dir);
-	if ((status != VCHIQ_RETRY) || fatal_signal_pending(current) || !waiter->bulk_waiter.bulk) {
+	if ((status != -EAGAIN) || fatal_signal_pending(current) || !waiter->bulk_waiter.bulk) {
 		struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
 
 		if (bulk) {
@@ -1001,7 +1001,7 @@ add_completion(struct vchiq_instance *instance, enum vchiq_reason reason,
 		DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
 		if (wait_for_completion_interruptible(&instance->remove_event)) {
 			vchiq_log_info(vchiq_arm_log_level, "service_callback interrupted");
-			return VCHIQ_RETRY;
+			return -EAGAIN;
 		} else if (instance->closing) {
 			vchiq_log_info(vchiq_arm_log_level, "service_callback closing");
 			return 0;
@@ -1122,7 +1122,7 @@ service_callback(struct vchiq_instance *instance, enum vchiq_reason reason,
 				vchiq_log_info(vchiq_arm_log_level, "%s interrupted", __func__);
 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
 				vchiq_service_put(service);
-				return VCHIQ_RETRY;
+				return -EAGAIN;
 			} else if (instance->closing) {
 				vchiq_log_info(vchiq_arm_log_level, "%s closing", __func__);
 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_dev.c

@@ -132,7 +132,7 @@ vchiq_ioc_queue_message(struct vchiq_instance *instance, unsigned int handle,
 
 	if (status == -EINVAL)
 		return -EIO;
-	else if (status == VCHIQ_RETRY)
+	else if (status == -EAGAIN)
 		return -EINTR;
 	return 0;
 }
@@ -192,7 +192,7 @@ static int vchiq_ioc_create_service(struct vchiq_instance *instance,
 		status = vchiq_open_service_internal(service, instance->pid);
 		if (status) {
 			vchiq_remove_service(instance, service->handle);
-			return (status == VCHIQ_RETRY) ?
+			return (status == -EAGAIN) ?
 				-EINTR : -EIO;
 		}
 	}
@@ -338,7 +338,7 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
 		goto out;
 	}
 
-	if ((status != VCHIQ_RETRY) || fatal_signal_pending(current) ||
+	if ((status != -EAGAIN) || fatal_signal_pending(current) ||
 	    !waiter->bulk_waiter.bulk) {
 		if (waiter->bulk_waiter.bulk) {
 			/* Cancel the signal when the transfer completes. */
@@ -366,7 +366,7 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
 		return ret;
 	else if (status == -EINVAL)
 		return -EIO;
-	else if (status == VCHIQ_RETRY)
+	else if (status == -EAGAIN)
 		return -EINTR;
 	return 0;
 }
@@ -686,7 +686,7 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		 */
 		if (user_service->close_pending &&
 		    wait_for_completion_interruptible(&user_service->close_event))
-			status = VCHIQ_RETRY;
+			status = -EAGAIN;
 		break;
 	}
 
@@ -864,7 +864,7 @@ vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	if (ret == 0) {
 		if (status == -EINVAL)
 			ret = -EIO;
-		else if (status == VCHIQ_RETRY)
+		else if (status == -EAGAIN)
 			ret = -EINTR;
 	}