[S390] cio: use sense-pgid operation for path verification

Set-pgid operations fail for some device types under z/VM for which
the hypervisor has already set the pgid. Also reserved devices or
changed pgids are not correctly recognized. Fix these problems by
using a combination of sense-pgid and set-pgid and by also accepting
pre-defined pgid settings.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 95 insertions, 53 deletions

diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 3323042ba755..4d54abd82b8c 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -141,8 +141,8 @@ static void spid_do(struct ccw_device *cdev)
         struct ccw_request *req = &cdev->private->req;
         u8 fn;
 
-        /* Adjust lpm if paths are not set in pam. */
-        req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam);
+        /* Use next available path that is not already in correct state. */
+        req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam & ~sch->vpm);
         if (!req->lpm)
                 goto out_nopath;
         /* Channel program setup. */
@@ -199,6 +199,19 @@ err:
         verify_done(cdev, rc);
 }
 
+static void spid_start(struct ccw_device *cdev)
+{
+        struct ccw_request *req = &cdev->private->req;
+
+        /* Initialize request data. */
+        memset(req, 0, sizeof(*req));
+        req->timeout    = PGID_TIMEOUT;
+        req->maxretries = PGID_RETRIES;
+        req->lpm        = 0x80;
+        req->callback   = spid_callback;
+        spid_do(cdev);
+}
+
 static int pgid_cmp(struct pgid *p1, struct pgid *p2)
 {
         return memcmp((char *) p1 + 1, (char *) p2 + 1,
@@ -241,6 +254,40 @@ static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
         *p = first;
 }
 
+static u8 pgid_to_vpm(struct ccw_device *cdev)
+{
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+        struct pgid *pgid;
+        int i;
+        int lpm;
+        u8 vpm = 0;
+
+        /* Set VPM bits for paths which are already in the target state. */
+        for (i = 0; i < 8; i++) {
+                lpm = 0x80 >> i;
+                if ((cdev->private->pgid_valid_mask & lpm) == 0)
+                        continue;
+                pgid = &cdev->private->pgid[i];
+                if (sch->opm & lpm) {
+                        if (pgid->inf.ps.state1 != SNID_STATE1_GROUPED)
+                                continue;
+                } else {
+                        if (pgid->inf.ps.state1 != SNID_STATE1_UNGROUPED)
+                                continue;
+                }
+                if (cdev->private->flags.mpath) {
+                        if (pgid->inf.ps.state3 != SNID_STATE3_MULTI_PATH)
+                                continue;
+                } else {
+                        if (pgid->inf.ps.state3 != SNID_STATE3_SINGLE_PATH)
+                                continue;
+                }
+                vpm |= lpm;
+        }
+
+        return vpm;
+}
+
 static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid)
 {
         int i;
@@ -255,6 +302,7 @@ static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid)
 static void snid_done(struct ccw_device *cdev, int rc)
 {
         struct ccw_dev_id *id = &cdev->private->dev_id;
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
         struct pgid *pgid;
         int mismatch = 0;
         int reserved = 0;
@@ -263,18 +311,38 @@ static void snid_done(struct ccw_device *cdev, int rc)
         if (rc)
                 goto out;
         pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset);
-        if (!mismatch) {
-                pgid_fill(cdev, pgid);
-                cdev->private->flags.pgid_rdy = 1;
-        }
         if (reserved)
                 rc = -EUSERS;
+        else if (mismatch)
+                rc = -EOPNOTSUPP;
+        else {
+                sch->vpm = pgid_to_vpm(cdev);
+                pgid_fill(cdev, pgid);
+        }
 out:
-        CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x mism=%d "
-                      "rsvd=%d reset=%d\n", id->ssid, id->devno, rc,
-                      cdev->private->pgid_valid_mask, mismatch, reserved,
-                      reset);
-        ccw_device_sense_pgid_done(cdev, rc);
+        CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x vpm=%02x "
+                      "mism=%d rsvd=%d reset=%d\n", id->ssid, id->devno, rc,
+                      cdev->private->pgid_valid_mask, sch->vpm, mismatch,
+                      reserved, reset);
+        switch (rc) {
+        case 0:
+                /* Anything left to do? */
+                if (sch->vpm == sch->schib.pmcw.pam) {
+                        verify_done(cdev, sch->vpm == 0 ? -EACCES : 0);
+                        return;
+                }
+                /* Perform path-grouping. */
+                spid_start(cdev);
+                break;
+        case -EOPNOTSUPP:
+                /* Path-grouping not supported. */
+                cdev->private->flags.pgroup = 0;
+                cdev->private->flags.mpath = 0;
+                verify_start(cdev);
+                break;
+        default:
+                verify_done(cdev, rc);
+        }
 }
 
 /*
@@ -333,33 +401,6 @@ err:
         snid_done(cdev, rc);
 }
 
-/**
- * ccw_device_sense_pgid_start - perform SENSE PGID
- * @cdev: ccw device
- *
- * Execute a SENSE PGID channel program on each path to @cdev to update its
- * PGID information. When finished, call ccw_device_sense_id_done with a
- * return code specifying the result.
- */
-void ccw_device_sense_pgid_start(struct ccw_device *cdev)
-{
-        struct ccw_request *req = &cdev->private->req;
-
-        CIO_TRACE_EVENT(4, "snid");
-        CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
-        /* Initialize PGID data. */
-        memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid));
-        cdev->private->flags.pgid_rdy = 0;
-        cdev->private->pgid_valid_mask = 0;
-        /* Initialize request data. */
-        memset(req, 0, sizeof(*req));
-        req->timeout    = PGID_TIMEOUT;
-        req->maxretries = PGID_RETRIES;
-        req->callback   = snid_callback;
-        req->lpm        = 0x80;
-        snid_do(cdev);
-}
-
 /*
  * Perform path verification.
  */
@@ -367,6 +408,7 @@ static void verify_start(struct ccw_device *cdev)
 {
         struct subchannel *sch = to_subchannel(cdev->dev.parent);
         struct ccw_request *req = &cdev->private->req;
+        struct ccw_dev_id *devid = &cdev->private->dev_id;
 
         sch->vpm = 0;
         /* Initialize request data. */
@@ -375,9 +417,13 @@ static void verify_start(struct ccw_device *cdev)
         req->maxretries = PGID_RETRIES;
         req->lpm        = 0x80;
         if (cdev->private->flags.pgroup) {
-                req->callback   = spid_callback;
-                spid_do(cdev);
+                CIO_TRACE_EVENT(4, "snid");
+                CIO_HEX_EVENT(4, devid, sizeof(*devid));
+                req->callback   = snid_callback;
+                snid_do(cdev);
         } else {
+                CIO_TRACE_EVENT(4, "nop");
+                CIO_HEX_EVENT(4, devid, sizeof(*devid));
                 req->filter     = nop_filter;
                 req->callback   = nop_callback;
                 nop_do(cdev);
@@ -398,19 +444,15 @@ void ccw_device_verify_start(struct ccw_device *cdev)
 {
         CIO_TRACE_EVENT(4, "vrfy");
         CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
-        if (!cdev->private->flags.pgid_rdy) {
-                /* No pathgrouping possible. */
-                cdev->private->flags.pgroup = 0;
-                cdev->private->flags.mpath = 0;
-        } else {
-                /*
-                 * Initialize pathgroup and multipath state with target values.
-                 * They may change in the course of path verification.
-                 */
-                cdev->private->flags.pgroup = cdev->private->options.pgroup;
-                cdev->private->flags.mpath = cdev->private->options.mpath;
-
-        }
+        /* Initialize PGID data. */
+        memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid));
+        cdev->private->pgid_valid_mask = 0;
+        /*
+         * Initialize pathgroup and multipath state with target values.
+         * They may change in the course of path verification.
+         */
+        cdev->private->flags.pgroup = cdev->private->options.pgroup;
+        cdev->private->flags.mpath = cdev->private->options.mpath;
         cdev->private->flags.doverify = 0;
         verify_start(cdev);
 }