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authorSebastian Ott <sebott@linux.vnet.ibm.com>2016-07-14 11:30:37 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2016-07-15 14:31:59 +0200
commit0b601373778c770d7536b1d1761c3b2c06e4eb24 (patch)
tree5f7003c8e117db1bffacaa3102352e422cfb8f48 /drivers/s390/cio
parent6228c2a51edccf3e01fc4db065aac91b4cafdc76 (diff)
s390/cio: make fmt1 channel path descriptor optional
Not all machines / hypervisors support the chsc commands to fetch the fmt1 descriptor. When these commands fail the channel path would currently not be available to linux. Since users of these descriptors can already deal with invalid data make fetching it optional. The only data that is mandatory for us is the fmt0 channel path descriptor. Also make the return code for missing facilities in chsc_get_channel_measurement_chars consistent to other functions. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-rw-r--r--drivers/s390/cio/chp.c11
-rw-r--r--drivers/s390/cio/chsc.c2
2 files changed, 8 insertions, 5 deletions
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 50597f9522fe..d3b72eab2b8f 100644
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -428,11 +428,14 @@ int chp_update_desc(struct channel_path *chp)
if (rc)
return rc;
- rc = chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
- if (rc)
- return rc;
+ /*
+ * Fetching the following data is optional. Not all machines or
+ * hypervisors implement the required chsc commands.
+ */
+ chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
+ chsc_get_channel_measurement_chars(chp);
- return chsc_get_channel_measurement_chars(chp);
+ return 0;
}
/**
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 452193f7298c..39bb2ea7b78f 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -1020,7 +1020,7 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
chp->cmg = -1;
if (!css_chsc_characteristics.scmc || !css_chsc_characteristics.secm)
- return 0;
+ return -EINVAL;
spin_lock_irq(&chsc_page_lock);
memset(chsc_page, 0, PAGE_SIZE);