6 files changed, 115 insertions, 11 deletions

diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c
index 7f206ed44fdf..d15f8b4d78bd 100644
--- a/drivers/s390/cio/ccwreq.c
+++ b/drivers/s390/cio/ccwreq.c
@@ -38,9 +38,13 @@ static u16 ccwreq_next_path(struct ccw_device *cdev)
 {
         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 @@ void ccw_request_start(struct ccw_device *cdev)
 {
         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;
@@ -182,6 +190,8 @@ static enum io_status ccwreq_status(struct ccw_device *cdev, struct irb *lcirb)
                 /* Ask the driver what to do */
                 if (cdev->drv && cdev->drv->uc_handler) {
                         todo = cdev->drv->uc_handler(cdev, lcirb);
+                        CIO_TRACE_EVENT(2, "uc_response");
+                        CIO_HEX_EVENT(2, &todo, sizeof(todo));
                         switch (todo) {
                         case UC_TODO_RETRY:
                                 return IO_STATUS_ERROR;
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 407d0e9adfaf..4cbb1a6ca33c 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -29,6 +29,7 @@
 #include "chsc.h"
 
 static void *sei_page;
+static DEFINE_SPINLOCK(siosl_lock);
 static DEFINE_SPINLOCK(sda_lock);
 
 /**
@@ -48,6 +49,7 @@ int chsc_error_from_response(int response)
         case 0x0007:
         case 0x0008:
         case 0x000a:
+        case 0x0104:
                 return -EINVAL;
         case 0x0004:
                 return -EOPNOTSUPP;
@@ -974,3 +976,49 @@ int chsc_sstpi(void *page, void *result, size_t size)
         return (rr->response.code == 0x0001) ? 0 : -EIO;
 }
 
+static struct {
+        struct chsc_header request;
+        u32 word1;
+        struct subchannel_id sid;
+        u32 word3;
+        struct chsc_header response;
+        u32 word[11];
+} __attribute__ ((packed)) siosl_area __attribute__ ((__aligned__(PAGE_SIZE)));
+
+int chsc_siosl(struct subchannel_id schid)
+{
+        unsigned long flags;
+        int ccode;
+        int rc;
+
+        spin_lock_irqsave(&siosl_lock, flags);
+        memset(&siosl_area, 0, sizeof(siosl_area));
+        siosl_area.request.length = 0x0010;
+        siosl_area.request.code = 0x0046;
+        siosl_area.word1 = 0x80000000;
+        siosl_area.sid = schid;
+
+        ccode = chsc(&siosl_area);
+        if (ccode > 0) {
+                if (ccode == 3)
+                        rc = -ENODEV;
+                else
+                        rc = -EBUSY;
+                CIO_MSG_EVENT(2, "chsc: chsc failed for 0.%x.%04x (ccode=%d)\n",
+                              schid.ssid, schid.sch_no, ccode);
+                goto out;
+        }
+        rc = chsc_error_from_response(siosl_area.response.code);
+        if (rc)
+                CIO_MSG_EVENT(2, "chsc: siosl failed for 0.%x.%04x (rc=%04x)\n",
+                              schid.ssid, schid.sch_no,
+                              siosl_area.response.code);
+        else
+                CIO_MSG_EVENT(4, "chsc: siosl succeeded for 0.%x.%04x\n",
+                              schid.ssid, schid.sch_no);
+out:
+        spin_unlock_irqrestore(&siosl_lock, flags);
+
+        return rc;
+}
+EXPORT_SYMBOL_GPL(chsc_siosl);
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 37aa611d4ac5..5453013f094b 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -80,4 +80,6 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp);
 
 int chsc_error_from_response(int response);
 
+int chsc_siosl(struct subchannel_id schid);
+
 #endif
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 6d229f3523a0..51bd3687d163 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -36,6 +36,7 @@
 #include "ioasm.h"
 #include "io_sch.h"
 #include "blacklist.h"
+#include "chsc.h"
 
 static struct timer_list recovery_timer;
 static DEFINE_SPINLOCK(recovery_lock);
@@ -486,9 +487,11 @@ static int online_store_handle_offline(struct ccw_device *cdev)
                 spin_lock_irq(cdev->ccwlock);
                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
                 spin_unlock_irq(cdev->ccwlock);
-        } else if (cdev->online && cdev->drv && cdev->drv->set_offline)
+                return 0;
+        }
+        if (cdev->drv && cdev->drv->set_offline)
                 return ccw_device_set_offline(cdev);
-        return 0;
+        return -EINVAL;
 }
 
 static int online_store_recog_and_online(struct ccw_device *cdev)
@@ -505,8 +508,8 @@ static int online_store_recog_and_online(struct ccw_device *cdev)
                         return -EAGAIN;
         }
         if (cdev->drv && cdev->drv->set_online)
-                ccw_device_set_online(cdev);
-        return 0;
+                return ccw_device_set_online(cdev);
+        return -EINVAL;
 }
 
 static int online_store_handle_online(struct ccw_device *cdev, int force)
@@ -598,6 +601,25 @@ available_show (struct device *dev, struct device_attribute *attr, char *buf)
         }
 }
 
+static ssize_t
+initiate_logging(struct device *dev, struct device_attribute *attr,
+                 const char *buf, size_t count)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        int rc;
+
+        rc = chsc_siosl(sch->schid);
+        if (rc < 0) {
+                pr_warning("Logging for subchannel 0.%x.%04x failed with "
+                           "errno=%d\n",
+                           sch->schid.ssid, sch->schid.sch_no, rc);
+                return rc;
+        }
+        pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
+                  sch->schid.ssid, sch->schid.sch_no);
+        return count;
+}
+
 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
@@ -605,10 +627,12 @@ static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 static DEVICE_ATTR(online, 0644, online_show, online_store);
 static DEVICE_ATTR(availability, 0444, available_show, NULL);
+static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
 
 static struct attribute *io_subchannel_attrs[] = {
         &dev_attr_chpids.attr,
         &dev_attr_pimpampom.attr,
+        &dev_attr_logging.attr,
         NULL,
 };
 
@@ -2036,6 +2060,21 @@ void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
         }
 }
 
+/**
+ * ccw_device_siosl() - initiate logging
+ * @cdev: ccw device
+ *
+ * This function is used to invoke model-dependent logging within the channel
+ * subsystem.
+ */
+int ccw_device_siosl(struct ccw_device *cdev)
+{
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+
+        return chsc_siosl(sch->schid);
+}
+EXPORT_SYMBOL_GPL(ccw_device_siosl);
+
 MODULE_LICENSE("GPL");
 EXPORT_SYMBOL(ccw_device_set_online);
 EXPORT_SYMBOL(ccw_device_set_offline);
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 6facb5499a65..82a5ad0d63f6 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -208,6 +208,7 @@ static void spid_start(struct ccw_device *cdev)
         req->timeout    = PGID_TIMEOUT;
         req->maxretries = PGID_RETRIES;
         req->lpm        = 0x80;
+        req->singlepath = 1;
         req->callback   = spid_callback;
         spid_do(cdev);
 }
@@ -420,6 +421,7 @@ static void verify_start(struct ccw_device *cdev)
         req->timeout    = PGID_TIMEOUT;
         req->maxretries = PGID_RETRIES;
         req->lpm        = 0x80;
+        req->singlepath = 1;
         if (cdev->private->flags.pgroup) {
                 CIO_TRACE_EVENT(4, "snid");
                 CIO_HEX_EVENT(4, devid, sizeof(*devid));
@@ -507,6 +509,7 @@ void ccw_device_disband_start(struct ccw_device *cdev)
         req->timeout    = PGID_TIMEOUT;
         req->maxretries = PGID_RETRIES;
         req->lpm        = sch->schib.pmcw.pam & sch->opm;
+        req->singlepath = 1;
         req->callback   = disband_callback;
         fn = SPID_FUNC_DISBAND;
         if (cdev->private->flags.mpath)
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index b9ce712a7f25..469ef93f2302 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -92,11 +92,12 @@ enum io_status {
  * @filter: optional callback to adjust request status based on IRB data
  * @callback: final callback
  * @data: user-defined pointer passed to all callbacks
+ * @singlepath: if set, use only one path from @lpm per start I/O
+ * @cancel: non-zero if request was cancelled
+ * @done: non-zero if request was finished
  * @mask: current path mask
  * @retries: current number of retries
  * @drc: delayed return code
- * @cancel: non-zero if request was cancelled
- * @done: non-zero if request was finished
  */
 struct ccw_request {
         struct ccw1 *cp;
@@ -108,12 +109,13 @@ struct ccw_request {
                                  enum io_status);
         void (*callback)(struct ccw_device *, void *, int);
         void *data;
+        unsigned int singlepath:1;
         /* These fields are used internally. */
+        unsigned int cancel:1;
+        unsigned int done:1;
         u16 mask;
         u16 retries;
         int drc;
-        int cancel:1;
-        int done:1;
 } __attribute__((packed));
 
 /*