Merge branches 'for-4.4/upstream-fixes', 'for-4.5/async-suspend', 'for-4.5/container...

[mirror_ubuntu-artful-kernel.git] / drivers / s390 / cio / cio.c

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index b5620e818d6b91307c329cfe67f2de5ac4847ca5..690b8547e828deb81d94a2646459d2babc79dc24 100644 (file)
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -925,18 +925,32 @@ void reipl_ccw_dev(struct ccw_dev_id *devid)
 
 int __init cio_get_iplinfo(struct cio_iplinfo *iplinfo)
 {
+       static struct chsc_sda_area sda_area __initdata;
        struct subchannel_id schid;
        struct schib schib;
 
        schid = *(struct subchannel_id *)&S390_lowcore.subchannel_id;
        if (!schid.one)
                return -ENODEV;
+
+       if (schid.ssid) {
+               /*
+                * Firmware should have already enabled MSS but whoever started
+                * the kernel might have initiated a channel subsystem reset.
+                * Ensure that MSS is enabled.
+                */
+               memset(&sda_area, 0, sizeof(sda_area));
+               if (__chsc_enable_facility(&sda_area, CHSC_SDA_OC_MSS))
+                       return -ENODEV;
+       }
        if (stsch_err(schid, &schib))
                return -ENODEV;
        if (schib.pmcw.st != SUBCHANNEL_TYPE_IO)
                return -ENODEV;
        if (!schib.pmcw.dnv)
                return -ENODEV;
+
+       iplinfo->ssid = schid.ssid;
        iplinfo->devno = schib.pmcw.dev;
        iplinfo->is_qdio = schib.pmcw.qf;
        return 0;