[S390] cio: Channel-path configure function.

Add a new attribute to the channel-path sysfs directory through which
channel-path configure operations can be triggered. Also listen for
hardware events requesting channel-path configure operations and
process them accordingly.

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

11 files changed, 318 insertions, 61 deletions

diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 8a5839147f8a..0e92c8c89860 100644
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -10,9 +10,14 @@
 #include <linux/bug.h>
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/wait.h>
+#include <linux/mutex.h>
 #include <asm/errno.h>
+#include <asm/chpid.h>
+#include <asm/sclp.h>
 
-#include "chpid.h"
 #include "cio.h"
 #include "css.h"
 #include "ioasm.h"
@@ -20,6 +25,32 @@
 #include "chp.h"
 
 #define to_channelpath(device) container_of(device, struct channel_path, dev)
+#define CHP_INFO_UPDATE_INTERVAL        1*HZ
+
+enum cfg_task_t {
+        cfg_none,
+        cfg_configure,
+        cfg_deconfigure
+};
+
+/* Map for pending configure tasks. */
+static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
+static DEFINE_MUTEX(cfg_lock);
+static int cfg_busy;
+
+/* Map for channel-path status. */
+static struct sclp_chp_info chp_info;
+static DEFINE_MUTEX(info_lock);
+
+/* Time after which channel-path status may be outdated. */
+static unsigned long chp_info_expires;
+
+/* Workqueue to perform pending configure tasks. */
+static struct workqueue_struct *chp_wq;
+static struct work_struct cfg_work;
+
+/* Wait queue for configure completion events. */
+static wait_queue_head_t cfg_wait_queue;
 
 /* Return channel_path struct for given chpid. */
 static inline struct channel_path *chpid_to_chp(struct chp_id chpid)
@@ -251,6 +282,43 @@ static ssize_t chp_status_write(struct device *dev,
 
 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
 
+static ssize_t chp_configure_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        struct channel_path *cp;
+        int status;
+
+        cp = container_of(dev, struct channel_path, dev);
+        status = chp_info_get_status(cp->chpid);
+        if (status < 0)
+                return status;
+
+        return snprintf(buf, PAGE_SIZE, "%d\n", status);
+}
+
+static int cfg_wait_idle(void);
+
+static ssize_t chp_configure_write(struct device *dev,
+                                   struct device_attribute *attr,
+                                   const char *buf, size_t count)
+{
+        struct channel_path *cp;
+        int val;
+        char delim;
+
+        if (sscanf(buf, "%d %c", &val, &delim) != 1)
+                return -EINVAL;
+        if (val != 0 && val != 1)
+                return -EINVAL;
+        cp = container_of(dev, struct channel_path, dev);
+        chp_cfg_schedule(cp->chpid, val);
+        cfg_wait_idle();
+
+        return count;
+}
+
+static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
+
 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
                              char *buf)
 {
@@ -293,6 +361,7 @@ static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
 
 static struct attribute * chp_attrs[] = {
         &dev_attr_status.attr,
+        &dev_attr_configure.attr,
         &dev_attr_type.attr,
         &dev_attr_cmg.attr,
         &dev_attr_shared.attr,
@@ -323,6 +392,8 @@ int chp_new(struct chp_id chpid)
         struct channel_path *chp;
         int ret;
 
+        if (chp_is_registered(chpid))
+                return 0;
         chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
         if (!chp)
                 return -ENOMEM;
@@ -435,3 +506,180 @@ int chp_process_crw(int id, int status)
                 return 0;
         }
 }
+
+static inline int info_bit_num(struct chp_id id)
+{
+        return id.id + id.cssid * (__MAX_CHPID + 1);
+}
+
+/* Force chp_info refresh on next call to info_validate(). */
+static void info_expire(void)
+{
+        mutex_lock(&info_lock);
+        chp_info_expires = jiffies - 1;
+        mutex_unlock(&info_lock);
+}
+
+/* Ensure that chp_info is up-to-date. */
+static int info_update(void)
+{
+        int rc;
+
+        mutex_lock(&info_lock);
+        rc = 0;
+        if (time_after(jiffies, chp_info_expires)) {
+                /* Data is too old, update. */
+                rc = sclp_chp_read_info(&chp_info);
+                chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
+        }
+        mutex_unlock(&info_lock);
+
+        return rc;
+}
+
+/**
+ * chp_info_get_status - retrieve configure status of a channel-path
+ * @chpid: channel-path ID
+ *
+ * On success, return 0 for standby, 1 for configured, 2 for reserved,
+ * 3 for not recognized. Return negative error code on error.
+ */
+int chp_info_get_status(struct chp_id chpid)
+{
+        int rc;
+        int bit;
+
+        rc = info_update();
+        if (rc)
+                return rc;
+
+        bit = info_bit_num(chpid);
+        mutex_lock(&info_lock);
+        if (!chp_test_bit(chp_info.recognized, bit))
+                rc = CHP_STATUS_NOT_RECOGNIZED;
+        else if (chp_test_bit(chp_info.configured, bit))
+                rc = CHP_STATUS_CONFIGURED;
+        else if (chp_test_bit(chp_info.standby, bit))
+                rc = CHP_STATUS_STANDBY;
+        else
+                rc = CHP_STATUS_RESERVED;
+        mutex_unlock(&info_lock);
+
+        return rc;
+}
+
+/* Return configure task for chpid. */
+static enum cfg_task_t cfg_get_task(struct chp_id chpid)
+{
+        return chp_cfg_task[chpid.cssid][chpid.id];
+}
+
+/* Set configure task for chpid. */
+static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
+{
+        chp_cfg_task[chpid.cssid][chpid.id] = cfg;
+}
+
+/* Perform one configure/deconfigure request. Reschedule work function until
+ * last request. */
+static void cfg_func(struct work_struct *work)
+{
+        struct chp_id chpid;
+        enum cfg_task_t t;
+
+        mutex_lock(&cfg_lock);
+        t = cfg_none;
+        chp_id_for_each(&chpid) {
+                t = cfg_get_task(chpid);
+                if (t != cfg_none) {
+                        cfg_set_task(chpid, cfg_none);
+                        break;
+                }
+        }
+        mutex_unlock(&cfg_lock);
+
+        switch (t) {
+        case cfg_configure:
+                sclp_chp_configure(chpid);
+                info_expire();
+                chsc_chp_online(chpid);
+                break;
+        case cfg_deconfigure:
+                sclp_chp_deconfigure(chpid);
+                info_expire();
+                chsc_chp_offline(chpid);
+                break;
+        case cfg_none:
+                /* Get updated information after last change. */
+                info_update();
+                mutex_lock(&cfg_lock);
+                cfg_busy = 0;
+                mutex_unlock(&cfg_lock);
+                wake_up_interruptible(&cfg_wait_queue);
+                return;
+        }
+        queue_work(chp_wq, &cfg_work);
+}
+
+/**
+ * chp_cfg_schedule - schedule chpid configuration request
+ * @chpid - channel-path ID
+ * @configure - Non-zero for configure, zero for deconfigure
+ *
+ * Schedule a channel-path configuration/deconfiguration request.
+ */
+void chp_cfg_schedule(struct chp_id chpid, int configure)
+{
+        CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
+                      configure);
+        mutex_lock(&cfg_lock);
+        cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
+        cfg_busy = 1;
+        mutex_unlock(&cfg_lock);
+        queue_work(chp_wq, &cfg_work);
+}
+
+/**
+ * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
+ * @chpid - channel-path ID
+ *
+ * Cancel an active channel-path deconfiguration request if it has not yet
+ * been performed.
+ */
+void chp_cfg_cancel_deconfigure(struct chp_id chpid)
+{
+        CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
+        mutex_lock(&cfg_lock);
+        if (cfg_get_task(chpid) == cfg_deconfigure)
+                cfg_set_task(chpid, cfg_none);
+        mutex_unlock(&cfg_lock);
+}
+
+static int cfg_wait_idle(void)
+{
+        if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
+                return -ERESTARTSYS;
+        return 0;
+}
+
+static int __init chp_init(void)
+{
+        struct chp_id chpid;
+
+        chp_wq = create_singlethread_workqueue("cio_chp");
+        if (!chp_wq)
+                return -ENOMEM;
+        INIT_WORK(&cfg_work, cfg_func);
+        init_waitqueue_head(&cfg_wait_queue);
+        if (info_update())
+                return 0;
+        /* Register available channel-paths. */
+        chp_id_for_each(&chpid) {
+                if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
+                        chp_new(chpid);
+        }
+
+        return 0;
+}
+
+subsys_initcall(chp_init);
diff --git a/drivers/s390/cio/chp.h b/drivers/s390/cio/chp.h
index ac2b1a9c3bc2..862af69d9707 100644
--- a/drivers/s390/cio/chp.h
+++ b/drivers/s390/cio/chp.h
@@ -10,10 +10,23 @@
 
 #include <linux/types.h>
 #include <linux/device.h>
-
-#include "chpid.h"
+#include <asm/chpid.h>
 #include "chsc.h"
 
+#define CHP_STATUS_STANDBY              0
+#define CHP_STATUS_CONFIGURED           1
+#define CHP_STATUS_RESERVED             2
+#define CHP_STATUS_NOT_RECOGNIZED       3
+
+static inline int chp_test_bit(u8 *bitmap, int num)
+{
+        int byte = num >> 3;
+        int mask = 128 >> (num & 7);
+
+        return (bitmap[byte] & mask) ? 1 : 0;
+}
+
+
 struct channel_path {
         struct chp_id chpid;
         int state;
@@ -33,5 +46,8 @@ int 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);
+void chp_cfg_schedule(struct chp_id chpid, int configure);
+void chp_cfg_cancel_deconfigure(struct chp_id chpid);
+int chp_info_get_status(struct chp_id chpid);
 
 #endif /* S390_CHP_H */
diff --git a/drivers/s390/cio/chpid.h b/drivers/s390/cio/chpid.h
deleted file mode 100644
index 44cc00ed9b59..000000000000
--- a/drivers/s390/cio/chpid.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- *  drivers/s390/cio/chpid.h
- *
- *    Copyright IBM Corp. 2007
- *    Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
- */
-
-#ifndef S390_CHP_ID_H
-#define S390_CHP_ID_H S390_CHP_ID_H
-
-#include <linux/string.h>
-#include <asm/types.h>
-#include "css.h"
-
-struct chp_id {
-        u8 reserved1;
-        u8 cssid;
-        u8 reserved2;
-        u8 id;
-} __attribute__((packed));
-
-static inline void chp_id_init(struct chp_id *chpid)
-{
-        memset(chpid, 0, sizeof(struct chp_id));
-}
-
-static inline int chp_id_is_equal(struct chp_id *a, struct chp_id *b)
-{
-        return (a->id == b->id) && (a->cssid == b->cssid);
-}
-
-static inline void chp_id_next(struct chp_id *chpid)
-{
-        if (chpid->id < __MAX_CHPID)
-                chpid->id++;
-        else {
-                chpid->id = 0;
-                chpid->cssid++;
-        }
-}
-
-static inline int chp_id_is_valid(struct chp_id *chpid)
-{
-        return (chpid->cssid <= __MAX_CSSID);
-}
-
-
-#define chp_id_for_each(c) \
-        for (chp_id_init(c); chp_id_is_valid(c); chp_id_next(c))
-
-#endif /* S390_CHP_ID_H */
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index d99f525eac08..3dec460bba27 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -15,12 +15,12 @@
 #include <linux/device.h>
 
 #include <asm/cio.h>
+#include <asm/chpid.h>
 
 #include "css.h"
 #include "cio.h"
 #include "cio_debug.h"
 #include "ioasm.h"
-#include "chpid.h"
 #include "chp.h"
 #include "chsc.h"
 
@@ -498,6 +498,45 @@ static int chsc_process_sei_res_acc(struct chsc_sei_area *sei_area)
         return rc;
 }
 
+struct chp_config_data {
+        u8 map[32];
+        u8 op;
+        u8 pc;
+};
+
+static int chsc_process_sei_chp_config(struct chsc_sei_area *sei_area)
+{
+        struct chp_config_data *data;
+        struct chp_id chpid;
+        int num;
+
+        CIO_CRW_EVENT(4, "chsc: channel-path-configuration notification\n");
+        if (sei_area->rs != 0)
+                return 0;
+        data = (struct chp_config_data *) &(sei_area->ccdf);
+        chp_id_init(&chpid);
+        for (num = 0; num <= __MAX_CHPID; num++) {
+                if (!chp_test_bit(data->map, num))
+                        continue;
+                chpid.id = num;
+                printk(KERN_WARNING "cio: processing configure event %d for "
+                       "chpid %x.%02x\n", data->op, chpid.cssid, chpid.id);
+                switch (data->op) {
+                case 0:
+                        chp_cfg_schedule(chpid, 1);
+                        break;
+                case 1:
+                        chp_cfg_schedule(chpid, 0);
+                        break;
+                case 2:
+                        chp_cfg_cancel_deconfigure(chpid);
+                        break;
+                }
+        }
+
+        return 0;
+}
+
 static int chsc_process_sei(struct chsc_sei_area *sei_area)
 {
         int rc;
@@ -514,6 +553,9 @@ static int chsc_process_sei(struct chsc_sei_area *sei_area)
         case 2: /* i/o resource accessibiliy */
                 rc = chsc_process_sei_res_acc(sei_area);
                 break;
+        case 8: /* channel-path-configuration notification */
+                rc = 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);
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 0e40defc6087..322586f27cc0 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -3,7 +3,7 @@
 
 #include <linux/types.h>
 #include <linux/device.h>
-#include "chpid.h"
+#include <asm/chpid.h>
 
 #define CHSC_SDA_OC_MSS   0x2
 
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 7dd0649c95d1..ea1defba5693 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -22,6 +22,7 @@
 #include <asm/setup.h>
 #include <asm/reset.h>
 #include <asm/ipl.h>
+#include <asm/chpid.h>
 #include "airq.h"
 #include "cio.h"
 #include "css.h"
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 35154a210357..e62ab5c52863 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -3,6 +3,7 @@
 
 #include "schid.h"
 #include <linux/mutex.h>
+#include <linux/device.h>
 
 /*
  * where we put the ssd info
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index 4319e1ced791..b2b1a265c602 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -5,8 +5,10 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 #include <linux/device.h>
+#include <linux/types.h>
 
 #include <asm/cio.h>
+#include <asm/chpid.h>
 
 #include "schid.h"
 
@@ -149,8 +151,6 @@ extern void css_reiterate_subchannels(void);
 
 #define __MAX_SUBCHANNEL 65535
 #define __MAX_SSID 3
-#define __MAX_CHPID 255
-#define __MAX_CSSID 0
 
 struct channel_subsystem {
         u8 cssid;
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index db3d1b990f58..d6226881d0df 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -15,6 +15,7 @@
 
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
+#include <asm/chpid.h>
 
 #include "cio.h"
 #include "cio_debug.h"
@@ -22,7 +23,6 @@
 #include "device.h"
 #include "chsc.h"
 #include "ioasm.h"
-#include "chpid.h"
 #include "chp.h"
 
 int
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index d819ae2ee9ae..16f59fcb66b1 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -16,13 +16,13 @@
 
 #include <asm/ccwdev.h>
 #include <asm/idals.h>
+#include <asm/chpid.h>
 
 #include "cio.h"
 #include "cio_debug.h"
 #include "css.h"
 #include "chsc.h"
 #include "device.h"
-#include "chpid.h"
 #include "chp.h"
 
 int ccw_device_set_options_mask(struct ccw_device *cdev, unsigned long flags)
diff --git a/drivers/s390/cio/ioasm.h b/drivers/s390/cio/ioasm.h
index 78c7db6daa84..7153dd959082 100644
--- a/drivers/s390/cio/ioasm.h
+++ b/drivers/s390/cio/ioasm.h
@@ -1,8 +1,8 @@
 #ifndef S390_CIO_IOASM_H
 #define S390_CIO_IOASM_H
 
+#include <asm/chpid.h>
 #include "schid.h"
-#include "chpid.h"
 
 /*
  * TPI info structure