11 files changed, 235 insertions, 236 deletions

diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile
index fe7b3ffa1ea..cfaf77b320f 100644
--- a/drivers/s390/cio/Makefile
+++ b/drivers/s390/cio/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the S/390 common i/o drivers
 #
 
-obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o
+obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o
 ccw_device-objs += device.o device_fsm.o device_ops.o
 ccw_device-objs += device_id.o device_pgid.o device_status.o
 obj-y += ccw_device.o cmf.o
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 0e92c8c8986..ac289e6eadf 100644
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -491,7 +491,7 @@ void *chp_get_chp_desc(struct chp_id chpid)
  * Handle channel-report-words indicating that the status of a channel-path
  * has changed.
  */
-int chp_process_crw(int id, int status)
+void chp_process_crw(int id, int status)
 {
         struct chp_id chpid;
 
@@ -500,11 +500,9 @@ int chp_process_crw(int id, int status)
         if (status) {
                 if (!chp_is_registered(chpid))
                         chp_new(chpid);
-                return chsc_chp_online(chpid);
-        } else {
+                chsc_chp_online(chpid);
+        } else
                 chsc_chp_offline(chpid);
-                return 0;
-        }
 }
 
 static inline int info_bit_num(struct chp_id id)
diff --git a/drivers/s390/cio/chp.h b/drivers/s390/cio/chp.h
index 862af69d970..65286563c59 100644
--- a/drivers/s390/cio/chp.h
+++ b/drivers/s390/cio/chp.h
@@ -42,7 +42,7 @@ int chp_get_status(struct chp_id chpid);
 u8 chp_get_sch_opm(struct subchannel *sch);
 int chp_is_registered(struct chp_id chpid);
 void *chp_get_chp_desc(struct chp_id chpid);
-int chp_process_crw(int id, int available);
+void chp_process_crw(int id, int available);
 void chp_remove_cmg_attr(struct channel_path *chp);
 int chp_add_cmg_attr(struct channel_path *chp);
 int chp_new(struct chp_id chpid);
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 02615eb4398..89a130a6265 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -195,12 +195,8 @@ static void terminate_internal_io(struct subchannel *sch)
         if (cio_clear(sch)) {
                 /* Recheck device in case clear failed. */
                 sch->lpm = 0;
-                if (device_trigger_verify(sch) != 0) {
-                        if(css_enqueue_subchannel_slow(sch->schid)) {
-                                css_clear_subchannel_slow_list();
-                                need_rescan = 1;
-                        }
-                }
+                if (device_trigger_verify(sch) != 0)
+                        css_schedule_eval(sch->schid);
                 return;
         }
         /* Request retry of internal operation. */
@@ -262,11 +258,8 @@ s390_subchannel_remove_chpid(struct device *dev, void *data)
 
 out_unreg:
         sch->lpm = 0;
-        if (css_enqueue_subchannel_slow(sch->schid)) {
-                css_clear_subchannel_slow_list();
-                need_rescan = 1;
-        }
         spin_unlock_irq(sch->lock);
+        css_schedule_eval(sch->schid);
         return 0;
 }
 
@@ -281,9 +274,6 @@ void chsc_chp_offline(struct chp_id chpid)
                 return;
         bus_for_each_dev(&css_bus_type, NULL, &chpid,
                          s390_subchannel_remove_chpid);
-
-        if (need_rescan || css_slow_subchannels_exist())
-                queue_work(slow_path_wq, &slow_path_work);
 }
 
 struct res_acc_data {
@@ -331,7 +321,6 @@ static int
 s390_process_res_acc_new_sch(struct subchannel_id schid)
 {
         struct schib schib;
-        int ret;
         /*
          * We don't know the device yet, but since a path
          * may be available now to the device we'll have
@@ -342,15 +331,10 @@ s390_process_res_acc_new_sch(struct subchannel_id schid)
          */
         if (stsch_err(schid, &schib))
                 /* We're through */
-                return need_rescan ? -EAGAIN : -ENXIO;
+                return -ENXIO;
 
         /* Put it on the slow path. */
-        ret = css_enqueue_subchannel_slow(schid);
-        if (ret) {
-                css_clear_subchannel_slow_list();
-                need_rescan = 1;
-                return -EAGAIN;
-        }
+        css_schedule_eval(schid);
         return 0;
 }
 
@@ -392,10 +376,8 @@ __s390_process_res_acc(struct subchannel_id schid, void *data)
 }
 
 
-static int
-s390_process_res_acc (struct res_acc_data *res_data)
+static void s390_process_res_acc (struct res_acc_data *res_data)
 {
-        int rc;
         char dbf_txt[15];
 
         sprintf(dbf_txt, "accpr%x.%02x", res_data->chpid.cssid,
@@ -413,12 +395,7 @@ s390_process_res_acc (struct res_acc_data *res_data)
          * The more information we have (info), the less scanning
          * will we have to do.
          */
-        rc = for_each_subchannel(__s390_process_res_acc, res_data);
-        if (css_slow_subchannels_exist())
-                rc = -EAGAIN;
-        else if (rc != -EAGAIN)
-                rc = 0;
-        return rc;
+        for_each_subchannel(__s390_process_res_acc, res_data);
 }
 
 static int
@@ -470,7 +447,7 @@ struct chsc_sei_area {
         /* ccdf has to be big enough for a link-incident record */
 } __attribute__ ((packed));
 
-static int chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
+static void chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
 {
         struct chp_id chpid;
         int id;
@@ -478,7 +455,7 @@ static int chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
         CIO_CRW_EVENT(4, "chsc: link incident (rs=%02x, rs_id=%04x)\n",
                       sei_area->rs, sei_area->rsid);
         if (sei_area->rs != 4)
-                return 0;
+                return;
         id = __get_chpid_from_lir(sei_area->ccdf);
         if (id < 0)
                 CIO_CRW_EVENT(4, "chsc: link incident - invalid LIR\n");
@@ -487,21 +464,18 @@ static int chsc_process_sei_link_incident(struct chsc_sei_area *sei_area)
                 chpid.id = id;
                 chsc_chp_offline(chpid);
         }
-
-        return 0;
 }
 
-static int chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
+static void chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
 {
         struct res_acc_data res_data;
         struct chp_id chpid;
         int status;
-        int rc;
 
         CIO_CRW_EVENT(4, "chsc: resource accessibility event (rs=%02x, "
                       "rs_id=%04x)\n", sei_area->rs, sei_area->rsid);
         if (sei_area->rs != 4)
-                return 0;
+                return;
         chp_id_init(&chpid);
         chpid.id = sei_area->rsid;
         /* allocate a new channel path structure, if needed */
@@ -509,7 +483,7 @@ static int chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
         if (status < 0)
                 chp_new(chpid);
         else if (!status)
-                return 0;
+                return;
         memset(&res_data, 0, sizeof(struct res_acc_data));
         res_data.chpid = chpid;
         if ((sei_area->vf & 0xc0) != 0) {
@@ -521,9 +495,7 @@ static int chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
                         /* link address */
                         res_data.fla_mask = 0xff00;
         }
-        rc = s390_process_res_acc(&res_data);
-
-        return rc;
+        s390_process_res_acc(&res_data);
 }
 
 struct chp_config_data {
@@ -532,7 +504,7 @@ struct chp_config_data {
         u8 pc;
 };
 
-static int chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
+static void chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
 {
         struct chp_config_data *data;
         struct chp_id chpid;
@@ -540,7 +512,7 @@ static int chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
 
         CIO_CRW_EVENT(4, "chsc: channel-path-configuration notification\n");
         if (sei_area->rs != 0)
-                return 0;
+                return;
         data = (struct chp_config_data *) &(sei_area->ccdf);
         chp_id_init(&chpid);
         for (num = 0; num <= __MAX_CHPID; num++) {
@@ -561,52 +533,44 @@ static int chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
                         break;
                 }
         }
-
-        return 0;
 }
 
-static int chsc_process_sei(struct chsc_sei_area *sei_area)
+static void chsc_process_sei(struct chsc_sei_area *sei_area)
 {
-        int rc;
-
         /* Check if we might have lost some information. */
-        if (sei_area->flags & 0x40)
+        if (sei_area->flags & 0x40) {
                 CIO_CRW_EVENT(2, "chsc: event overflow\n");
+                css_schedule_eval_all();
+        }
         /* which kind of information was stored? */
-        rc = 0;
         switch (sei_area->cc) {
         case 1: /* link incident*/
-                rc = chsc_process_sei_link_incident(sei_area);
+                chsc_process_sei_link_incident(sei_area);
                 break;
         case 2: /* i/o resource accessibiliy */
-                rc = chsc_process_sei_res_acc(sei_area);
+                chsc_process_sei_res_acc(sei_area);
                 break;
         case 8: /* channel-path-configuration notification */
-                rc = chsc_process_sei_chp_config(sei_area);
+                chsc_process_sei_chp_config(sei_area);
                 break;
         default: /* other stuff */
                 CIO_CRW_EVENT(4, "chsc: unhandled sei content code %d\n",
                               sei_area->cc);
                 break;
         }
-
-        return rc;
 }
 
-int chsc_process_crw(void)
+void chsc_process_crw(void)
 {
         struct chsc_sei_area *sei_area;
-        int ret;
-        int rc;
 
         if (!sei_page)
-                return 0;
+                return;
         /* Access to sei_page is serialized through machine check handler
          * thread, so no need for locking. */
         sei_area = sei_page;
 
         CIO_TRACE_EVENT( 2, "prcss");
-        ret = 0;
         do {
                 memset(sei_area, 0, sizeof(*sei_area));
                 sei_area->request.length = 0x0010;
@@ -616,37 +580,26 @@ int chsc_process_crw(void)
 
                 if (sei_area->response.code == 0x0001) {
                         CIO_CRW_EVENT(4, "chsc: sei successful\n");
-                        rc = chsc_process_sei(sei_area);
-                        if (rc)
-                                ret = rc;
+                        chsc_process_sei(sei_area);
                 } else {
                         CIO_CRW_EVENT(2, "chsc: sei failed (rc=%04x)\n",
                                       sei_area->response.code);
-                        ret = 0;
                         break;
                 }
         } while (sei_area->flags & 0x80);
-
-        return ret;
 }
 
 static int
 __chp_add_new_sch(struct subchannel_id schid)
 {
         struct schib schib;
-        int ret;
 
         if (stsch_err(schid, &schib))
                 /* We're through */
-                return need_rescan ? -EAGAIN : -ENXIO;
+                return -ENXIO;
 
         /* Put it on the slow path. */
-        ret = css_enqueue_subchannel_slow(schid);
-        if (ret) {
-                css_clear_subchannel_slow_list();
-                need_rescan = 1;
-                return -EAGAIN;
-        }
+        css_schedule_eval(schid);
         return 0;
 }
 
@@ -693,22 +646,15 @@ __chp_add(struct subchannel_id schid, void *data)
         return 0;
 }
 
-int chsc_chp_online(struct chp_id chpid)
+void chsc_chp_online(struct chp_id chpid)
 {
-        int rc;
         char dbf_txt[15];
 
         sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);
         CIO_TRACE_EVENT(2, dbf_txt);
 
-        if (chp_get_status(chpid) == 0)
-                return 0;
-        rc = for_each_subchannel(__chp_add, &chpid);
-        if (css_slow_subchannels_exist())
-                rc = -EAGAIN;
-        if (rc != -EAGAIN)
-                rc = 0;
-        return rc;
+        if (chp_get_status(chpid) != 0)
+                for_each_subchannel(__chp_add, &chpid);
 }
 
 static void __s390_subchannel_vary_chpid(struct subchannel *sch,
@@ -749,12 +695,8 @@ static void __s390_subchannel_vary_chpid(struct subchannel *sch,
                                         sch->driver->verify(&sch->dev);
                         }
                 } else if (!sch->lpm) {
-                        if (device_trigger_verify(sch) != 0) {
-                                if (css_enqueue_subchannel_slow(sch->schid)) {
-                                        css_clear_subchannel_slow_list();
-                                        need_rescan = 1;
-                                }
-                        }
+                        if (device_trigger_verify(sch) != 0)
+                                css_schedule_eval(sch->schid);
                 } else if (sch->driver && sch->driver->verify)
                         sch->driver->verify(&sch->dev);
                 break;
@@ -801,11 +743,7 @@ __s390_vary_chpid_on(struct subchannel_id schid, void *data)
                 /* We're through */
                 return -ENXIO;
         /* Put it on the slow path. */
-        if (css_enqueue_subchannel_slow(schid)) {
-                css_clear_subchannel_slow_list();
-                need_rescan = 1;
-                return -EAGAIN;
-        }
+        css_schedule_eval(schid);
         return 0;
 }
 
@@ -826,8 +764,6 @@ int chsc_chp_vary(struct chp_id chpid, int on)
         if (on)
                 /* Scan for new devices on varied on path. */
                 for_each_subchannel(__s390_vary_chpid_on, NULL);
-        if (need_rescan || css_slow_subchannels_exist())
-                queue_work(slow_path_wq, &slow_path_work);
         return 0;
 }
 
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 322586f27cc..742ef57d2c5 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -36,7 +36,7 @@ struct channel_path_desc {
 struct channel_path;
 
 extern int css_get_ssd_info(struct subchannel *);
-extern int chsc_process_crw(void);
+extern void chsc_process_crw(void);
 
 struct css_general_char {
         u64 : 41;
@@ -79,7 +79,7 @@ extern int chsc_secm(struct channel_subsystem *, int);
 int chsc_chp_vary(struct chp_id chpid, int on);
 int chsc_determine_channel_path_description(struct chp_id chpid,
                                             struct channel_path_desc *desc);
-int chsc_chp_online(struct chp_id chpid);
+void chsc_chp_online(struct chp_id chpid);
 void chsc_chp_offline(struct chp_id chpid);
 int chsc_get_channel_measurement_chars(struct channel_path *chp);
 
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index fe0ace7aece..fcc641e578f 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -20,8 +20,8 @@
 #include "ioasm.h"
 #include "chsc.h"
 #include "device.h"
+#include "idset.h"
 
-int need_rescan = 0;
 int css_init_done = 0;
 static int need_reprobe = 0;
 static int max_ssid = 0;
@@ -306,7 +306,7 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
         return css_probe_device(schid);
 }
 
-static int css_evaluate_subchannel(struct subchannel_id schid, int slow)
+static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
 {
         struct subchannel *sch;
         int ret;
@@ -317,53 +317,66 @@ static int css_evaluate_subchannel(struct subchannel_id schid, int slow)
                 put_device(&sch->dev);
         } else
                 ret = css_evaluate_new_subchannel(schid, slow);
-
-        return ret;
+        if (ret == -EAGAIN)
+                css_schedule_eval(schid);
 }
 
-static int
-css_rescan_devices(struct subchannel_id schid, void *data)
+static struct idset *slow_subchannel_set;
+static spinlock_t slow_subchannel_lock;
+
+static int __init slow_subchannel_init(void)
 {
-        return css_evaluate_subchannel(schid, 1);
+        spin_lock_init(&slow_subchannel_lock);
+        slow_subchannel_set = idset_sch_new();
+        if (!slow_subchannel_set) {
+                printk(KERN_WARNING "cio: could not allocate slow subchannel "
+                       "set\n");
+                return -ENOMEM;
+        }
+        return 0;
 }
 
-struct slow_subchannel {
-        struct list_head slow_list;
-        struct subchannel_id schid;
-};
-
-static LIST_HEAD(slow_subchannels_head);
-static DEFINE_SPINLOCK(slow_subchannel_lock);
+subsys_initcall(slow_subchannel_init);
 
-static void
-css_trigger_slow_path(struct work_struct *unused)
+static void css_slow_path_func(struct work_struct *unused)
 {
-        CIO_TRACE_EVENT(4, "slowpath");
-
-        if (need_rescan) {
-                need_rescan = 0;
-                for_each_subchannel(css_rescan_devices, NULL);
-                return;
-        }
+        struct subchannel_id schid;
 
+        CIO_TRACE_EVENT(4, "slowpath");
         spin_lock_irq(&slow_subchannel_lock);
-        while (!list_empty(&slow_subchannels_head)) {
-                struct slow_subchannel *slow_sch =
-                        list_entry(slow_subchannels_head.next,
-                                   struct slow_subchannel, slow_list);
-
-                list_del_init(slow_subchannels_head.next);
+        init_subchannel_id(&schid);
+        while (idset_sch_get_first(slow_subchannel_set, &schid)) {
+                idset_sch_del(slow_subchannel_set, schid);
                 spin_unlock_irq(&slow_subchannel_lock);
-                css_evaluate_subchannel(slow_sch->schid, 1);
+                css_evaluate_subchannel(schid, 1);
                 spin_lock_irq(&slow_subchannel_lock);
-                kfree(slow_sch);
         }
         spin_unlock_irq(&slow_subchannel_lock);
 }
 
-DECLARE_WORK(slow_path_work, css_trigger_slow_path);
+static DECLARE_WORK(slow_path_work, css_slow_path_func);
 struct workqueue_struct *slow_path_wq;
 
+void css_schedule_eval(struct subchannel_id schid)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&slow_subchannel_lock, flags);
+        idset_sch_add(slow_subchannel_set, schid);
+        queue_work(slow_path_wq, &slow_path_work);
+        spin_unlock_irqrestore(&slow_subchannel_lock, flags);
+}
+
+void css_schedule_eval_all(void)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&slow_subchannel_lock, flags);
+        idset_fill(slow_subchannel_set);
+        queue_work(slow_path_wq, &slow_path_work);
+        spin_unlock_irqrestore(&slow_subchannel_lock, flags);
+}
+
 /* Reprobe subchannel if unregistered. */
 static int reprobe_subchannel(struct subchannel_id schid, void *data)
 {
@@ -426,33 +439,14 @@ void css_schedule_reprobe(void)
 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
 
 /*
- * Rescan for new devices. FIXME: This is slow.
- * This function is called when we have lost CRWs due to overflows and we have
- * to do subchannel housekeeping.
- */
-void
-css_reiterate_subchannels(void)
-{
-        css_clear_subchannel_slow_list();
-        need_rescan = 1;
-}
-
-/*
  * Called from the machine check handler for subchannel report words.
  */
-int
-css_process_crw(int rsid1, int rsid2)
+void css_process_crw(int rsid1, int rsid2)
 {
-        int ret;
         struct subchannel_id mchk_schid;
 
         CIO_CRW_EVENT(2, "source is subchannel %04X, subsystem id %x\n",
                       rsid1, rsid2);
-
-        if (need_rescan)
-                /* We need to iterate all subchannels anyway. */
-                return -EAGAIN;
-
         init_subchannel_id(&mchk_schid);
         mchk_schid.sch_no = rsid1;
         if (rsid2 != 0)
@@ -463,14 +457,7 @@ css_process_crw(int rsid1, int rsid2)
          * use stsch() to find out if the subchannel in question has come
          * or gone.
          */
-        ret = css_evaluate_subchannel(mchk_schid, 0);
-        if (ret == -EAGAIN) {
-                if (css_enqueue_subchannel_slow(mchk_schid)) {
-                        css_clear_subchannel_slow_list();
-                        need_rescan = 1;
-                }
-        }
-        return ret;
+        css_evaluate_subchannel(mchk_schid, 0);
 }
 
 static int __init
@@ -745,47 +732,6 @@ struct bus_type css_bus_type = {
 
 subsys_initcall(init_channel_subsystem);
 
-int
-css_enqueue_subchannel_slow(struct subchannel_id schid)
-{
-        struct slow_subchannel *new_slow_sch;
-        unsigned long flags;
-
-        new_slow_sch = kzalloc(sizeof(struct slow_subchannel), GFP_ATOMIC);
-        if (!new_slow_sch)
-                return -ENOMEM;
-        new_slow_sch->schid = schid;
-        spin_lock_irqsave(&slow_subchannel_lock, flags);
-        list_add_tail(&new_slow_sch->slow_list, &slow_subchannels_head);
-        spin_unlock_irqrestore(&slow_subchannel_lock, flags);
-        return 0;
-}
-
-void
-css_clear_subchannel_slow_list(void)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&slow_subchannel_lock, flags);
-        while (!list_empty(&slow_subchannels_head)) {
-                struct slow_subchannel *slow_sch =
-                        list_entry(slow_subchannels_head.next,
-                                   struct slow_subchannel, slow_list);
-
-                list_del_init(slow_subchannels_head.next);
-                kfree(slow_sch);
-        }
-        spin_unlock_irqrestore(&slow_subchannel_lock, flags);
-}
-
-
-
-int
-css_slow_subchannels_exist(void)
-{
-        return (!list_empty(&slow_subchannels_head));
-}
-
 MODULE_LICENSE("GPL");
 EXPORT_SYMBOL(css_bus_type);
 EXPORT_SYMBOL_GPL(css_characteristics_avail);
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index b2b1a265c60..4b3133a7bae 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -146,7 +146,7 @@ extern void css_sch_device_unregister(struct subchannel *);
 extern struct subchannel * get_subchannel_by_schid(struct subchannel_id);
 extern int css_init_done;
 extern int for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *);
-extern int css_process_crw(int, int);
+extern void css_process_crw(int, int);
 extern void css_reiterate_subchannels(void);
 
 #define __MAX_SUBCHANNEL 65535
@@ -186,16 +186,12 @@ int device_trigger_verify(struct subchannel *sch);
 void device_kill_pending_timer(struct subchannel *);
 
 /* Helper functions to build lists for the slow path. */
-extern int css_enqueue_subchannel_slow(struct subchannel_id schid);
-void css_walk_subchannel_slow_list(void (*fn)(unsigned long));
-void css_clear_subchannel_slow_list(void);
-int css_slow_subchannels_exist(void);
-extern int need_rescan;
+void css_schedule_eval(struct subchannel_id schid);
+void css_schedule_eval_all(void);
 
 int sch_is_pseudo_sch(struct subchannel *);
 
 extern struct workqueue_struct *slow_path_wq;
-extern struct work_struct slow_path_work;
 
 int subchannel_add_files (struct device *);
 extern struct attribute_group *subch_attr_groups[];
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index d6226881d0d..898ec3b2beb 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -222,10 +222,8 @@ __recover_lost_chpids(struct subchannel *sch, int old_lpm)
                 if (old_lpm & mask)
                         continue;
                 chpid.id = sch->schib.pmcw.chpid[i];
-                if (!chp_is_registered(chpid)) {
-                        need_rescan = 1;
-                        queue_work(slow_path_wq, &slow_path_work);
-                }
+                if (!chp_is_registered(chpid))
+                        css_schedule_eval_all();
         }
 }
 
diff --git a/drivers/s390/cio/idset.c b/drivers/s390/cio/idset.c
new file mode 100644
index 00000000000..16ea828e99f
--- /dev/null
+++ b/drivers/s390/cio/idset.c
@@ -0,0 +1,112 @@
+/*
+ *  drivers/s390/cio/idset.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#include <linux/slab.h>
+#include <asm/bitops.h>
+#include "idset.h"
+#include "css.h"
+
+struct idset {
+        int num_ssid;
+        int num_id;
+        unsigned long bitmap[0];
+};
+
+static inline unsigned long bitmap_size(int num_ssid, int num_id)
+{
+        return __BITOPS_WORDS(num_ssid * num_id) * sizeof(unsigned long);
+}
+
+static struct idset *idset_new(int num_ssid, int num_id)
+{
+        struct idset *set;
+
+        set = kzalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id),
+                      GFP_KERNEL);
+        if (set) {
+                set->num_ssid = num_ssid;
+                set->num_id = num_id;
+        }
+        return set;
+}
+
+void idset_free(struct idset *set)
+{
+        kfree(set);
+}
+
+void idset_clear(struct idset *set)
+{
+        memset(set->bitmap, 0, bitmap_size(set->num_ssid, set->num_id));
+}
+
+void idset_fill(struct idset *set)
+{
+        memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
+}
+
+static inline void idset_add(struct idset *set, int ssid, int id)
+{
+        set_bit(ssid * set->num_id + id, set->bitmap);
+}
+
+static inline void idset_del(struct idset *set, int ssid, int id)
+{
+        clear_bit(ssid * set->num_id + id, set->bitmap);
+}
+
+static inline int idset_contains(struct idset *set, int ssid, int id)
+{
+        return test_bit(ssid * set->num_id + id, set->bitmap);
+}
+
+static inline int idset_get_first(struct idset *set, int *ssid, int *id)
+{
+        int bitnum;
+
+        bitnum = find_first_bit(set->bitmap, set->num_ssid * set->num_id);
+        if (bitnum >= set->num_ssid * set->num_id)
+                return 0;
+        *ssid = bitnum / set->num_id;
+        *id = bitnum % set->num_id;
+        return 1;
+}
+
+struct idset *idset_sch_new(void)
+{
+        return idset_new(__MAX_SSID + 1, __MAX_SUBCHANNEL + 1);
+}
+
+void idset_sch_add(struct idset *set, struct subchannel_id schid)
+{
+        idset_add(set, schid.ssid, schid.sch_no);
+}
+
+void idset_sch_del(struct idset *set, struct subchannel_id schid)
+{
+        idset_del(set, schid.ssid, schid.sch_no);
+}
+
+int idset_sch_contains(struct idset *set, struct subchannel_id schid)
+{
+        return idset_contains(set, schid.ssid, schid.sch_no);
+}
+
+int idset_sch_get_first(struct idset *set, struct subchannel_id *schid)
+{
+        int ssid = 0;
+        int id = 0;
+        int rc;
+
+        rc = idset_get_first(set, &ssid, &id);
+        if (rc) {
+                init_subchannel_id(schid);
+                schid->ssid = ssid;
+                schid->sch_no = id;
+        }
+        return rc;
+}
diff --git a/drivers/s390/cio/idset.h b/drivers/s390/cio/idset.h
new file mode 100644
index 00000000000..144466ab8c1
--- /dev/null
+++ b/drivers/s390/cio/idset.h
@@ -0,0 +1,25 @@
+/*
+ *  drivers/s390/cio/idset.h
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
+ */
+
+#ifndef S390_IDSET_H
+#define S390_IDSET_H S390_IDSET_H
+
+#include "schid.h"
+
+struct idset;
+
+void idset_free(struct idset *set);
+void idset_clear(struct idset *set);
+void idset_fill(struct idset *set);
+
+struct idset *idset_sch_new(void);
+void idset_sch_add(struct idset *set, struct subchannel_id id);
+void idset_sch_del(struct idset *set, struct subchannel_id id);
+int idset_sch_contains(struct idset *set, struct subchannel_id id);
+int idset_sch_get_first(struct idset *set, struct subchannel_id *id);
+
+#endif /* S390_IDSET_H */
diff --git a/drivers/s390/s390mach.c b/drivers/s390/s390mach.c
index afd8a3c0f8d..644a06eba82 100644
--- a/drivers/s390/s390mach.c
+++ b/drivers/s390/s390mach.c
@@ -45,14 +45,13 @@ static int
 s390_collect_crw_info(void *param)
 {
         struct crw crw[2];
-        int ccode, ret, slow;
+        int ccode;
         struct semaphore *sem;
         unsigned int chain;
 
         sem = (struct semaphore *)param;
 repeat:
         down_interruptible(sem);
-        slow = 0;
         chain = 0;
         while (1) {
                 if (unlikely(chain > 1)) {
@@ -85,9 +84,8 @@ repeat:
                 /* Check for overflows. */
                 if (crw[chain].oflw) {
                         pr_debug("%s: crw overflow detected!\n", __FUNCTION__);
-                        css_reiterate_subchannels();
+                        css_schedule_eval_all();
                         chain = 0;
-                        slow = 1;
                         continue;
                 }
                 switch (crw[chain].rsc) {
@@ -95,10 +93,7 @@ repeat:
                         if (crw[0].chn && !chain)
                                 break;
                         pr_debug("source is subchannel %04X\n", crw[0].rsid);
-                        ret = css_process_crw (crw[0].rsid,
-                                               chain ? crw[1].rsid : 0);
-                        if (ret == -EAGAIN)
-                                slow = 1;
+                        css_process_crw(crw[0].rsid, chain ? crw[1].rsid : 0);
                         break;
                 case CRW_RSC_MONITOR:
                         pr_debug("source is monitoring facility\n");
@@ -117,28 +112,23 @@ repeat:
                         }
                         switch (crw[0].erc) {
                         case CRW_ERC_IPARM: /* Path has come. */
-                                ret = chp_process_crw(crw[0].rsid, 1);
+                                chp_process_crw(crw[0].rsid, 1);
                                 break;
                         case CRW_ERC_PERRI: /* Path has gone. */
                         case CRW_ERC_PERRN:
-                                ret = chp_process_crw(crw[0].rsid, 0);
+                                chp_process_crw(crw[0].rsid, 0);
                                 break;
                         default:
                                 pr_debug("Don't know how to handle erc=%x\n",
                                          crw[0].erc);
-                                ret = 0;
                         }
-                        if (ret == -EAGAIN)
-                                slow = 1;
                         break;
                 case CRW_RSC_CONFIG:
                         pr_debug("source is configuration-alert facility\n");
                         break;
                 case CRW_RSC_CSS:
                         pr_debug("source is channel subsystem\n");
-                        ret = chsc_process_crw();
-                        if (ret == -EAGAIN)
-                                slow = 1;
+                        chsc_process_crw();
                         break;
                 default:
                         pr_debug("unknown source\n");
@@ -147,8 +137,6 @@ repeat:
                 /* chain is always 0 or 1 here. */
                 chain = crw[chain].chn ? chain + 1 : 0;
         }
-        if (slow)
-                queue_work(slow_path_wq, &slow_path_work);
         goto repeat;
         return 0;
 }