[S390] ccwreq: add ability to use all paths
Change the ccwrequest infrastructure to use more than one channel
path per start I/O. A flag "singlepath" is added to struct
ccw_request - if set, the old behavior is used. This flag is set
for all exploiters of the ccwrequest infrastructure - so there
is no functional change through this patch.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c
index fd03687..d15f8b4 100644
--- a/drivers/s390/cio/ccwreq.c
+++ b/drivers/s390/cio/ccwreq.c
@@ -38,9 +38,13 @@
{
struct ccw_request *req = &cdev->private->req;
+ if (!req->singlepath) {
+ req->mask = 0;
+ goto out;
+ }
req->retries = req->maxretries;
req->mask = lpm_adjust(req->mask >>= 1, req->lpm);
-
+out:
return req->mask;
}
@@ -113,8 +117,12 @@
{
struct ccw_request *req = &cdev->private->req;
- /* Try all paths twice to counter link flapping. */
- req->mask = 0x8080;
+ if (req->singlepath) {
+ /* Try all paths twice to counter link flapping. */
+ req->mask = 0x8080;
+ } else
+ req->mask = req->lpm;
+
req->retries = req->maxretries;
req->mask = lpm_adjust(req->mask, req->lpm);
req->drc = 0;