s390/cio: Helper functions to read CSSID, IID, and CHID

Add helper functions to expose Channel Subsystem ID (CSSID), MIF Image Id
(IID), Channel ID (CHID) and Channel Path ID (CHPID).
These values are required by the qeth driver's exploitation of network-
address-change-notifications to determine which entries belong to this
interface.

Store the Partition identifier in System log, as this may be used to map
a Linux view to a Hardware view for debugging purpose.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index cdf44f398957..0fe7b2f2e7f5 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -733,6 +733,91 @@ int ccw_device_pnso(struct ccw_device *cdev,
 }
 EXPORT_SYMBOL_GPL(ccw_device_pnso);
 
+/**
+ * ccw_device_get_cssid() - obtain Channel Subsystem ID
+ * @cdev: device to obtain the CSSID for
+ * @cssid: The resulting Channel Subsystem ID
+ */
+int ccw_device_get_cssid(struct ccw_device *cdev, u8 *cssid)
+{
+	struct device *sch_dev = cdev->dev.parent;
+	struct channel_subsystem *css = to_css(sch_dev->parent);
+
+	if (css->id_valid)
+		*cssid = css->cssid;
+	return css->id_valid ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_cssid);
+
+/**
+ * ccw_device_get_iid() - obtain MIF-image ID
+ * @cdev: device to obtain the MIF-image ID for
+ * @iid: The resulting MIF-image ID
+ */
+int ccw_device_get_iid(struct ccw_device *cdev, u8 *iid)
+{
+	struct device *sch_dev = cdev->dev.parent;
+	struct channel_subsystem *css = to_css(sch_dev->parent);
+
+	if (css->id_valid)
+		*iid = css->iid;
+	return css->id_valid ? 0 : -ENODEV;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_iid);
+
+/**
+ * ccw_device_get_chpid() - obtain Channel Path ID
+ * @cdev: device to obtain the Channel Path ID for
+ * @chp_idx: Index of the channel path
+ * @chpid: The resulting Channel Path ID
+ */
+int ccw_device_get_chpid(struct ccw_device *cdev, int chp_idx, u8 *chpid)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	int mask;
+
+	if ((chp_idx < 0) || (chp_idx > 7))
+		return -EINVAL;
+	mask = 0x80 >> chp_idx;
+	if (!(sch->schib.pmcw.pim & mask))
+		return -ENODEV;
+
+	*chpid = sch->schib.pmcw.chpid[chp_idx];
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_chpid);
+
+/**
+ * ccw_device_get_chid() - obtain Channel ID associated with specified CHPID
+ * @cdev: device to obtain the Channel ID for
+ * @chp_idx: Index of the channel path
+ * @chid: The resulting Channel ID
+ */
+int ccw_device_get_chid(struct ccw_device *cdev, int chp_idx, u16 *chid)
+{
+	struct chp_id cssid_chpid;
+	struct channel_path *chp;
+	int rc;
+
+	chp_id_init(&cssid_chpid);
+	rc = ccw_device_get_chpid(cdev, chp_idx, &cssid_chpid.id);
+	if (rc)
+		return rc;
+	chp = chpid_to_chp(cssid_chpid);
+	if (!chp)
+		return -ENODEV;
+
+	mutex_lock(&chp->lock);
+	if (chp->desc_fmt1.flags & 0x10)
+		*chid = chp->desc_fmt1.chid;
+	else
+		rc = -ENODEV;
+	mutex_unlock(&chp->lock);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ccw_device_get_chid);
+
 /*
  * Allocate zeroed dma coherent 31 bit addressable memory using
  * the subchannels dma pool. Maximal size of allocation supported