Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / drivers / s390 / cio / device_ops.c

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index 6da84543dfe985cd500d9acce3af5ec0d6a5e14e..651976b54af80395547d675f1c538580521e0644 100644 (file)
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -686,6 +686,46 @@ int ccw_device_tm_start_timeout(struct ccw_device *cdev, struct tcw *tcw,
 }
 EXPORT_SYMBOL(ccw_device_tm_start_timeout);
 
+/**
+ * ccw_device_get_mdc - accumulate max data count
+ * @cdev: ccw device for which the max data count is accumulated
+ * @mask: mask of paths to use
+ *
+ * Return the number of 64K-bytes blocks all paths at least support
+ * for a transport command. Return values <= 0 indicate failures.
+ */
+int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
+{
+       struct subchannel *sch = to_subchannel(cdev->dev.parent);
+       struct channel_path_desc_fmt1 desc;
+       struct chp_id chpid;
+       int mdc = 0, ret, i;
+
+       /* Adjust requested path mask to excluded varied off paths. */
+       if (mask)
+               mask &= sch->lpm;
+       else
+               mask = sch->lpm;
+
+       chp_id_init(&chpid);
+       for (i = 0; i < 8; i++) {
+               if (!(mask & (0x80 >> i)))
+                       continue;
+               chpid.id = sch->schib.pmcw.chpid[i];
+               ret = chsc_determine_fmt1_channel_path_desc(chpid, &desc);
+               if (ret)
+                       return ret;
+               if (!desc.f)
+                       return 0;
+               if (!desc.r)
+                       mdc = 1;
+               mdc = mdc ? min(mdc, (int)desc.mdc) : desc.mdc;
+       }
+
+       return mdc;
+}
+EXPORT_SYMBOL(ccw_device_get_mdc);
+
 /**
  * ccw_device_tm_intrg - perform interrogate function
  * @cdev: ccw device on which to perform the interrogate function