This patch implements the new status accessor in the ccw device, as laid out in "[PATCH v2 1/1] ccw: add CCW_CMD_READ_STATUS". Changes from the RFC (back in September): - rebased Pierre Morel (1): virtio/s390: support READ_STATUS command for virtio-ccw drivers/s390/virtio/virtio_ccw.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) -- 2.6.6
Cornelia Huck
2016-Apr-11 11:23 UTC
[PATCH 1/1] virtio/s390: support READ_STATUS command for virtio-ccw
From: Pierre Morel <pmorel at linux.vnet.ibm.com> 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 at linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- drivers/s390/virtio/virtio_ccw.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index 8688ad4..d3a98d3 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) @@ -902,6 +904,28 @@ 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; } @@ -997,6 +1021,7 @@ 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: -- 2.6.6
Apparently Analagous Threads
- [PULL 3/5] virtio/s390: support READ_STATUS command for virtio-ccw
- [PATCH RFC 09/11] KVM: s390: Set virtio-ccw transport revision
- [PATCH 0/1] virtio_ccw: new status accessor in driver
- [PATCH 0/1] virtio_ccw: new status accessor in driver
- [PATCH 1/2] s390x/virtio-ccw: respond to READ_STATUS command