Commit 14c75793 authored by Halil Pasic's avatar Halil Pasic Committed by Heiko Carstens
Browse files

s390/virtio_ccw: Fix dma_parm pointer not set up 



At least since commit 334304ac ("dma-mapping: don't return errors
from dma_set_max_seg_size") setting up device.dma_parms is basically
mandated by the DMA API. As of now Channel (CCW) I/O in general does not
utilize the DMA API, except for virtio. For virtio-ccw however the
common virtio DMA infrastructure is such that most of the DMA stuff
hinges on the virtio parent device, which is a CCW device.

So lets set up the dma_parms pointer for the CCW parent device and hope
for the best!

Fixes: 334304ac ("dma-mapping: don't return errors from dma_set_max_seg_size")
Reported-by: default avatarMarc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: default avatarEric Farman <farman@linux.ibm.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Tested-by: default avatarMarc Hartmayer <mhartmay@linux.ibm.com>
Link: https://lore.kernel.org/r/20241007201030.204028-1-pasic@linux.ibm.com


Signed-off-by: default avatarHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 61997c1e

drivers/s390/virtio/virtio_ccw.c

+4 −0
Original line number Diff line number Diff line
@@ -58,6 +58,8 @@ struct virtio_ccw_device { 
	struct virtio_device vdev;

	__u8 config[VIRTIO_CCW_CONFIG_SIZE];

	struct ccw_device *cdev;

	/* we make cdev->dev.dma_parms point to this */

	struct device_dma_parameters dma_parms;

	__u32 curr_io;

	int err;

	unsigned int revision; /* Transport revision */
@@ -1303,6 +1305,7 @@ static int virtio_ccw_offline(struct ccw_device *cdev) 
	unregister_virtio_device(&vcdev->vdev);

	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);

	dev_set_drvdata(&cdev->dev, NULL);

	cdev->dev.dma_parms = NULL;

	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);

	return 0;

}
@@ -1366,6 +1369,7 @@ static int virtio_ccw_online(struct ccw_device *cdev) 
	}

	vcdev->vdev.dev.parent = &cdev->dev;

	vcdev->cdev = cdev;

	cdev->dev.dma_parms = &vcdev->dma_parms;

	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,

						sizeof(*vcdev->dma_area),

						&vcdev->dma_area_addr);