diff options
| author | Pierre Morel <pmorel@linux.vnet.ibm.com> | 2015-08-28 11:09:32 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2017-01-19 23:46:32 +0200 |
| commit | 7d3ce5ab9430504b6d91027919529f68fd14af9b (patch) | |
| tree | d853e17383f3380973f42fd1bebc2fb3cb8c01e6 /drivers/s390 | |
| parent | 47a4c49af6cc1982ce613c8ee79aab459d04c44c (diff) | |
| download | lwn-7d3ce5ab9430504b6d91027919529f68fd14af9b.tar.gz lwn-7d3ce5ab9430504b6d91027919529f68fd14af9b.zip | |
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: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/virtio/virtio_ccw.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index 639ed4e6afd1..01e3dcfd7c64 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -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 @@ out_free: 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: |