staging: vchiq_core: Factor out bulk transfer for (no/)callback mode

Factor out bulk transfer for VCHIQ_BULK_MODE_NOCALLBACK and
VCHIQ_BULK_MODE_CALLBACK mode into a separate dedicated function
bulk_xfer_callback_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.

bulk_xfer_callback_interruptible() also takes in 'mode' parameter to
differentiate between VCHIQ_BULK_MODE_NOCALLBACK and
VCHIQ_BULK_MODE_CALLBACK, which then is directly passed to
vchiq_bulk_xfer_queue_msg_interruptible() inside the function.

Adjust the calls to vchiq-dev.c ioctl interface and vchiq_arm.c
for the respective bulk transfers.
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Tested-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20240910051007.297227-5-umang.jain@ideasonboard.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -857,10 +857,10 @@ vchiq_bulk_transmit(struct vchiq_instance *instance, unsigned int handle, const
 		switch (mode) {
 		case VCHIQ_BULK_MODE_NOCALLBACK:
 		case VCHIQ_BULK_MODE_CALLBACK:
-			ret = vchiq_bulk_transfer(instance, handle,
-						  (void *)data, NULL,
-						  size, userdata, mode,
-						  VCHIQ_BULK_TRANSMIT);
+			ret = vchiq_bulk_xfer_callback_interruptible(instance, handle,
+								     (void *)data, NULL,
+								     size, mode, userdata,
+								     VCHIQ_BULK_TRANSMIT);
 			break;
 		case VCHIQ_BULK_MODE_BLOCKING:
 			ret = vchiq_blocking_bulk_transfer(instance, handle, (void *)data, size,
@@ -895,9 +895,10 @@ int vchiq_bulk_receive(struct vchiq_instance *instance, unsigned int handle,
 		switch (mode) {
 		case VCHIQ_BULK_MODE_NOCALLBACK:
 		case VCHIQ_BULK_MODE_CALLBACK:
-			ret = vchiq_bulk_transfer(instance, handle, data, NULL,
-						  size, userdata,
-						  mode, VCHIQ_BULK_RECEIVE);
+			ret = vchiq_bulk_xfer_callback_interruptible(instance, handle,
+								     (void *)data, NULL,
+								     size, mode, userdata,
+								     VCHIQ_BULK_RECEIVE);
 			break;
 		case VCHIQ_BULK_MODE_BLOCKING:
 			ret = vchiq_blocking_bulk_transfer(instance, handle, (void *)data, size,

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

@@ -3135,6 +3135,40 @@ vchiq_bulk_xfer_blocking_interruptible(struct vchiq_instance *instance, unsigned
 	return status;
 }
 
+int
+vchiq_bulk_xfer_callback_interruptible(struct vchiq_instance *instance, unsigned int handle,
+				       void *offset, void __user *uoffset, int size,
+				       enum vchiq_bulk_mode mode, void *userdata,
+				       enum vchiq_bulk_dir dir)
+{
+	struct vchiq_service *service = find_service_by_handle(instance, handle);
+	int status = -EINVAL;
+
+	if (!service)
+		return -EINVAL;
+
+	if (mode != VCHIQ_BULK_MODE_CALLBACK &&
+	    mode != VCHIQ_BULK_MODE_NOCALLBACK)
+		goto error_exit;
+
+	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

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

@@ -479,6 +479,12 @@ vchiq_bulk_xfer_blocking_interruptible(struct vchiq_instance *instance, unsigned
 				       void *offset, void __user *uoffset, int size,
 				       void __user *userdata, enum vchiq_bulk_dir dir);
 
+extern int
+vchiq_bulk_xfer_callback_interruptible(struct vchiq_instance *instance, unsigned int handle,
+				       void *offset, void __user *uoffset, int size,
+				       enum vchiq_bulk_mode mode, void *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

@@ -336,6 +336,12 @@ static int vchiq_irq_queue_bulk_tx_rx(struct vchiq_instance *instance,
 		goto bulk_transfer_handled;
 	} else {
 		userdata = args->userdata;
+
+		status = vchiq_bulk_xfer_callback_interruptible(instance, args->handle, NULL,
+								args->data, args->size,
+								args->mode, userdata, dir);
+
+		goto bulk_transfer_handled;
 	}
 
 	status = vchiq_bulk_transfer(instance, args->handle, NULL, args->data, args->size,