staging: vchiq_core: Factor out bulk transfer for blocking mode

Factor out bulk transfer for blocking mode into a separate dedicated
function bulk_xfer_blocking_interruptible(). It is suffixed by
"_interruptible" to denote that it can be interrupted and -EAGAIN
can be returned. It would be up to the users of the function to retry
the call in those cases.

Adjust the calls to vchiq-dev.c ioctl interface and vchiq_arm.c
for blocking bulk transfers.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Tested-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240910051007.297227-4-umang.jain@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -968,9 +968,8 @@ vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handl
 			return -ENOMEM;
 	}
 
-	ret = vchiq_bulk_transfer(instance, handle, data, NULL, size,
-				  &waiter->bulk_waiter,
-				  VCHIQ_BULK_MODE_BLOCKING, dir);
+	ret = vchiq_bulk_xfer_blocking_interruptible(instance, handle, data, NULL, size,
+						     &waiter->bulk_waiter, dir);
 	if ((ret != -EAGAIN) || fatal_signal_pending(current) || !waiter->bulk_waiter.bulk) {
 		struct vchiq_bulk *bulk = waiter->bulk_waiter.bulk;
 

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

@@ -2669,6 +2669,7 @@ vchiq_bulk_xfer_queue_msg_interruptible(struct vchiq_service *service,
 					enum vchiq_bulk_dir dir)
 {
 	struct vchiq_bulk_queue *queue;
+	struct bulk_waiter *bulk_waiter = NULL;
 	struct vchiq_bulk *bulk;
 	struct vchiq_state *state = service->state;
 	const char dir_char = (dir == VCHIQ_BULK_TRANSMIT) ? 't' : 'r';
@@ -2677,6 +2678,13 @@ vchiq_bulk_xfer_queue_msg_interruptible(struct vchiq_service *service,
 	int status = -EINVAL;
 	int payload[2];
 
+	if (mode == VCHIQ_BULK_MODE_BLOCKING) {
+		bulk_waiter = userdata;
+		init_completion(&bulk_waiter->event);
+		bulk_waiter->actual = 0;
+		bulk_waiter->bulk = NULL;
+	}
+
 	queue = (dir == VCHIQ_BULK_TRANSMIT) ?
 		&service->bulk_tx : &service->bulk_rx;
 
@@ -2753,6 +2761,14 @@ vchiq_bulk_xfer_queue_msg_interruptible(struct vchiq_service *service,
 		state->id, service->localport, dir_char, queue->local_insert,
 		queue->remote_insert, queue->process);
 
+        if (bulk_waiter) {
+                bulk_waiter->bulk = bulk;
+                if (wait_for_completion_interruptible(&bulk_waiter->event))
+                        status = -EAGAIN;
+                else if (bulk_waiter->actual == VCHIQ_BULK_ACTUAL_ABORTED)
+                        status = -EINVAL;
+        }
+
 	return status;
 
 unlock_both_error_exit:
@@ -3088,6 +3104,37 @@ vchiq_remove_service(struct vchiq_instance *instance, unsigned int handle)
 	return status;
 }
 
+int
+vchiq_bulk_xfer_blocking_interruptible(struct vchiq_instance *instance, unsigned int handle,
+				       void *offset, void __user *uoffset, int size,
+				       void __user *userdata, enum vchiq_bulk_dir dir)
+{
+	struct vchiq_service *service = find_service_by_handle(instance, handle);
+	enum vchiq_bulk_mode mode = VCHIQ_BULK_MODE_BLOCKING;
+	int status = -EINVAL;
+
+	if (!service)
+		return -EINVAL;
+
+	if (service->srvstate != VCHIQ_SRVSTATE_OPEN)
+		goto error_exit;
+
+	if (!offset && !uoffset)
+		goto error_exit;
+
+	if (vchiq_check_service(service))
+		goto error_exit;
+
+
+	status = vchiq_bulk_xfer_queue_msg_interruptible(service, offset, uoffset, size,
+							 userdata, mode, dir);
+
+error_exit:
+	vchiq_service_put(service);
+
+	return status;
+}
+
 /*
  * This function may be called by kernel threads or user threads.
  * User threads may receive -EAGAIN to indicate that a signal has been
@@ -3121,12 +3168,6 @@ int vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int handle,
 	case VCHIQ_BULK_MODE_NOCALLBACK:
 	case VCHIQ_BULK_MODE_CALLBACK:
 		break;
-	case VCHIQ_BULK_MODE_BLOCKING:
-		bulk_waiter = userdata;
-		init_completion(&bulk_waiter->event);
-		bulk_waiter->actual = 0;
-		bulk_waiter->bulk = NULL;
-		break;
 	default:
 		goto error_exit;
 	}

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_core.h

@@ -474,6 +474,11 @@ extern int
 vchiq_bulk_xfer_waiting_interruptible(struct vchiq_instance *instance,
 				      unsigned int handle, struct bulk_waiter *userdata);
 
+extern int
+vchiq_bulk_xfer_blocking_interruptible(struct vchiq_instance *instance, unsigned int handle,
+				       void *offset, void __user *uoffset, int size,
+				       void __user *userdata, enum vchiq_bulk_dir dir);
+
 extern int
 vchiq_bulk_transfer(struct vchiq_instance *instance, unsigned int handle, void *offset,
 		    void __user *uoffset, int size, void *userdata, enum vchiq_bulk_mode mode,

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

@@ -304,6 +304,12 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
 		}
 
 		userdata = &waiter->bulk_waiter;
+
+		status = vchiq_bulk_xfer_blocking_interruptible(instance, args->handle,
+								NULL, args->data, args->size,
+								userdata, dir);
+
+		goto bulk_transfer_handled;
 	} else if (args->mode == VCHIQ_BULK_MODE_WAITING) {
 		mutex_lock(&instance->bulk_waiter_list_mutex);
 		list_for_each_entry(iter, &instance->bulk_waiter_list,