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Commit 7d3ce5ab authored by Pierre Morel's avatar Pierre Morel Committed by Michael S. Tsirkin
Browse files

virtio/s390: support READ_STATUS command for virtio-ccw 



As virtio-1 introduced the possibility of the device manipulating the
status byte, revision 2 of the virtio-ccw transport introduced a means
of getting the status byte from the device via READ_STATUS. Let's wire
it up for revisions >= 2 and fall back to returning the stored status
byte if not supported.

Signed-off-by: default avatarPierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent 47a4c49a

drivers/s390/virtio/virtio_ccw.c

+25 −0
Original line number Diff line number Diff line
@@ -145,6 +145,7 @@ static struct airq_info *airq_areas[MAX_AIRQ_AREAS]; 
#define CCW_CMD_WRITE_CONF 0x21

#define CCW_CMD_WRITE_STATUS 0x31

#define CCW_CMD_READ_VQ_CONF 0x32

#define CCW_CMD_READ_STATUS 0x72

#define CCW_CMD_SET_IND_ADAPTER 0x73

#define CCW_CMD_SET_VIRTIO_REV 0x83
@@ -160,6 +161,7 @@ static struct airq_info *airq_areas[MAX_AIRQ_AREAS]; 
#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000

#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000

#define VIRTIO_CCW_DOING_SET_VIRTIO_REV 0x10000000

#define VIRTIO_CCW_DOING_READ_STATUS 0x20000000

#define VIRTIO_CCW_INTPARM_MASK 0xffff0000



static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)
@@ -892,6 +894,28 @@ static void virtio_ccw_set_config(struct virtio_device *vdev, 
static u8 virtio_ccw_get_status(struct virtio_device *vdev)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	u8 old_status = *vcdev->status;

	struct ccw1 *ccw;



	if (vcdev->revision < 1)

		return *vcdev->status;



	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);

	if (!ccw)

		return old_status;



	ccw->cmd_code = CCW_CMD_READ_STATUS;

	ccw->flags = 0;

	ccw->count = sizeof(*vcdev->status);

	ccw->cda = (__u32)(unsigned long)vcdev->status;

	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);

/*

 * If the channel program failed (should only happen if the device

 * was hotunplugged, and then we clean up via the machine check

 * handler anyway), vcdev->status was not overwritten and we just

 * return the old status, which is fine.

*/

	kfree(ccw);



	return *vcdev->status;

}
@@ -987,6 +1011,7 @@ static void virtio_ccw_check_activity(struct virtio_ccw_device *vcdev, 
		case VIRTIO_CCW_DOING_READ_CONFIG:

		case VIRTIO_CCW_DOING_WRITE_CONFIG:

		case VIRTIO_CCW_DOING_WRITE_STATUS:

		case VIRTIO_CCW_DOING_READ_STATUS:

		case VIRTIO_CCW_DOING_SET_VQ:

		case VIRTIO_CCW_DOING_SET_IND:

		case VIRTIO_CCW_DOING_SET_CONF_IND: