[S390] cio: Introduce modalias for css bus.

Add modalias and subchannel type attributes for all subchannels.
I/O subchannel specific attributes are now created in
io_subchannel_probe(). modalias and subchannel type are also
added to the uevent for the css bus. Also make the css modalias
known.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

7 files changed, 151 insertions, 24 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-css b/Documentation/ABI/testing/sysfs-bus-css
new file mode 100644
index 000000000000..b585ec258a08
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-css
@@ -0,0 +1,35 @@
+What:           /sys/bus/css/devices/.../type
+Date:           March 2008
+Contact:        Cornelia Huck <cornelia.huck@de.ibm.com>
+                linux-s390@vger.kernel.org
+Description:    Contains the subchannel type, as reported by the hardware.
+                This attribute is present for all subchannel types.
+
+What:           /sys/bus/css/devices/.../modalias
+Date:           March 2008
+Contact:        Cornelia Huck <cornelia.huck@de.ibm.com>
+                linux-s390@vger.kernel.org
+Description:    Contains the module alias as reported with uevents.
+                It is of the format css:t<type> and present for all
+                subchannel types.
+
+What:           /sys/bus/css/drivers/io_subchannel/.../chpids
+Date:           December 2002
+Contact:        Cornelia Huck <cornelia.huck@de.ibm.com>
+                linux-s390@vger.kernel.org
+Description:    Contains the ids of the channel paths used by this
+                subchannel, as reported by the channel subsystem
+                during subchannel recognition.
+                Note: This is an I/O-subchannel specific attribute.
+Users:          s390-tools, HAL
+
+What:           /sys/bus/css/drivers/io_subchannel/.../pimpampom
+Date:           December 2002
+Contact:        Cornelia Huck <cornelia.huck@de.ibm.com>
+                linux-s390@vger.kernel.org
+Description:    Contains the PIM/PAM/POM values, as reported by the
+                channel subsystem when last queried by the common I/O
+                layer (this implies that this attribute is not neccessarily
+                in sync with the values current in the channel subsystem).
+                Note: This is an I/O-subchannel specific attribute.
+Users:          s390-tools, HAL
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 6e933aebe013..4062748e8346 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -3,6 +3,7 @@
 
 #include <linux/mutex.h>
 #include <linux/device.h>
+#include <linux/mod_devicetable.h>
 #include <asm/chpid.h>
 #include "chsc.h"
 #include "schid.h"
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index b7f4b52c5a9a..53e7496dc90c 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -2,8 +2,7 @@
  *  drivers/s390/cio/css.c
  *  driver for channel subsystem
  *
- *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- *                       IBM Corporation
+ *    Copyright IBM Corp. 2002,2008
  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
  *               Cornelia Huck (cornelia.huck@de.ibm.com)
  */
@@ -210,6 +209,41 @@ void css_update_ssd_info(struct subchannel *sch)
         }
 }
 
+static ssize_t type_show(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct subchannel *sch = to_subchannel(dev);
+
+        return sprintf(buf, "%01x\n", sch->st);
+}
+
+static DEVICE_ATTR(type, 0444, type_show, NULL);
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+                             char *buf)
+{
+        struct subchannel *sch = to_subchannel(dev);
+
+        return sprintf(buf, "css:t%01X\n", sch->st);
+}
+
+static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
+
+static struct attribute *subch_attrs[] = {
+        &dev_attr_type.attr,
+        &dev_attr_modalias.attr,
+        NULL,
+};
+
+static struct attribute_group subch_attr_group = {
+        .attrs = subch_attrs,
+};
+
+static struct attribute_group *default_subch_attr_groups[] = {
+        &subch_attr_group,
+        NULL,
+};
+
 static int css_register_subchannel(struct subchannel *sch)
 {
         int ret;
@@ -218,16 +252,17 @@ static int css_register_subchannel(struct subchannel *sch)
         sch->dev.parent = &channel_subsystems[0]->device;
         sch->dev.bus = &css_bus_type;
         sch->dev.release = &css_subchannel_release;
-        sch->dev.groups = subch_attr_groups;
+        sch->dev.groups = default_subch_attr_groups;
         /*
          * We don't want to generate uevents for I/O subchannels that don't
          * have a working ccw device behind them since they will be
          * unregistered before they can be used anyway, so we delay the add
          * uevent until after device recognition was successful.
+         * Note that we suppress the uevent for all subchannel types;
+         * the subchannel driver can decide itself when it wants to inform
+         * userspace of its existence.
          */
-        if (!cio_is_console(sch->schid))
-                /* Console is special, no need to suppress. */
-                sch->dev.uevent_suppress = 1;
+        sch->dev.uevent_suppress = 1;
         css_update_ssd_info(sch);
         /* make it known to the system */
         ret = css_sch_device_register(sch);
@@ -236,6 +271,15 @@ static int css_register_subchannel(struct subchannel *sch)
                               sch->schid.ssid, sch->schid.sch_no, ret);
                 return ret;
         }
+        if (!sch->driver) {
+                /*
+                 * No driver matched. Generate the uevent now so that
+                 * a fitting driver module may be loaded based on the
+                 * modalias.
+                 */
+                sch->dev.uevent_suppress = 0;
+                kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+        }
         return ret;
 }
 
@@ -926,12 +970,25 @@ static void css_shutdown(struct device *dev)
                 sch->driver->shutdown(sch);
 }
 
+static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        int ret;
+
+        ret = add_uevent_var(env, "ST=%01X", sch->st);
+        if (ret)
+                return ret;
+        ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
+        return ret;
+}
+
 struct bus_type css_bus_type = {
         .name     = "css",
         .match    = css_bus_match,
         .probe    = css_probe,
         .remove   = css_remove,
         .shutdown = css_shutdown,
+        .uevent   = css_uevent,
 };
 
 /**
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index bfe0ada43f2c..e0fc7b499784 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -143,6 +143,4 @@ int css_sch_is_valid(struct schib *);
 
 extern struct workqueue_struct *slow_path_wq;
 void css_wait_for_slow_path(void);
-
-extern struct attribute_group *subch_attr_groups[];
 #endif
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 0ed5a81260bc..23b129fd4d8d 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -585,19 +585,14 @@ 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 struct attribute * subch_attrs[] = {
+static struct attribute *io_subchannel_attrs[] = {
         &dev_attr_chpids.attr,
         &dev_attr_pimpampom.attr,
         NULL,
 };
 
-static struct attribute_group subch_attr_group = {
-        .attrs = subch_attrs,
-};
-
-struct attribute_group *subch_attr_groups[] = {
-        &subch_attr_group,
-        NULL,
+static struct attribute_group io_subchannel_attr_group = {
+        .attrs = io_subchannel_attrs,
 };
 
 static struct attribute * ccwdev_attrs[] = {
@@ -1157,11 +1152,21 @@ static int io_subchannel_probe(struct subchannel *sch)
 
         cdev = sch_get_cdev(sch);
         if (cdev) {
+                rc = sysfs_create_group(&sch->dev.kobj,
+                                        &io_subchannel_attr_group);
+                if (rc)
+                        CIO_MSG_EVENT(0, "Failed to create io subchannel "
+                                      "attributes for subchannel "
+                                      "0.%x.%04x (rc=%d)\n",
+                                      sch->schid.ssid, sch->schid.sch_no, rc);
                 /*
                  * This subchannel already has an associated ccw_device.
-                 * Register it and exit. This happens for all early
-                 * device, e.g. the console.
+                 * Throw the delayed uevent for the subchannel, register
+                 * the ccw_device and exit. This happens for all early
+                 * devices, e.g. the console.
                  */
+                sch->dev.uevent_suppress = 0;
+                kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
                 cdev->dev.groups = ccwdev_attr_groups;
                 device_initialize(&cdev->dev);
                 ccw_device_register(cdev);
@@ -1184,11 +1189,17 @@ static int io_subchannel_probe(struct subchannel *sch)
          */
         dev_id.devno = sch->schib.pmcw.dev;
         dev_id.ssid = sch->schid.ssid;
+        rc = sysfs_create_group(&sch->dev.kobj,
+                                &io_subchannel_attr_group);
+        if (rc)
+                return rc;
         /* Allocate I/O subchannel private data. */
         sch->private = kzalloc(sizeof(struct io_subchannel_private),
                                GFP_KERNEL | GFP_DMA);
-        if (!sch->private)
-                return -ENOMEM;
+        if (!sch->private) {
+                rc = -ENOMEM;
+                goto out_err;
+        }
         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
         if (!cdev)
                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
@@ -1207,8 +1218,8 @@ static int io_subchannel_probe(struct subchannel *sch)
         }
         cdev = io_subchannel_create_ccwdev(sch);
         if (IS_ERR(cdev)) {
-                kfree(sch->private);
-                return PTR_ERR(cdev);
+                rc = PTR_ERR(cdev);
+                goto out_err;
         }
         rc = io_subchannel_recog(cdev, sch);
         if (rc) {
@@ -1217,9 +1228,12 @@ static int io_subchannel_probe(struct subchannel *sch)
                 spin_unlock_irqrestore(sch->lock, flags);
                 if (cdev->dev.release)
                         cdev->dev.release(&cdev->dev);
-                kfree(sch->private);
+                goto out_err;
         }
-
+        return 0;
+out_err:
+        kfree(sch->private);
+        sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
         return rc;
 }
 
@@ -1240,6 +1254,7 @@ io_subchannel_remove (struct subchannel *sch)
         ccw_device_unregister(cdev);
         put_device(&cdev->dev);
         kfree(sch->private);
+        sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
         return 0;
 }
 
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 69b2342d5ebb..1fd03e732e07 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -159,6 +159,15 @@ struct ap_device_id {
 
 #define AP_DEVICE_ID_MATCH_DEVICE_TYPE          0x01
 
+/* s390 css bus devices (subchannels) */
+struct css_device_id {
+        __u8 type; /* subchannel type */
+        __u8 pad1;
+        __u16 pad2;
+        __u32 pad3;
+        kernel_ulong_t driver_data;
+};
+
 #define ACPI_ID_LEN     16 /* only 9 bytes needed here, 16 bytes are used */
                            /* to workaround crosscompile issues */
 
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index cea4a790e1e9..37d5c363fbcd 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -304,6 +304,14 @@ static int do_ap_entry(const char *filename,
         return 1;
 }
 
+/* looks like: "css:tN" */
+static int do_css_entry(const char *filename,
+                        struct css_device_id *id, char *alias)
+{
+        sprintf(alias, "css:t%01X", id->type);
+        return 1;
+}
+
 /* Looks like: "serio:tyNprNidNexN" */
 static int do_serio_entry(const char *filename,
                           struct serio_device_id *id, char *alias)
@@ -680,6 +688,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
                 do_table(symval, sym->st_size,
                          sizeof(struct ap_device_id), "ap",
                          do_ap_entry, mod);
+        else if (sym_is(symname, "__mod_css_device_table"))
+                do_table(symval, sym->st_size,
+                         sizeof(struct css_device_id), "css",
+                         do_css_entry, mod);
         else if (sym_is(symname, "__mod_serio_device_table"))
                 do_table(symval, sym->st_size,
                          sizeof(struct serio_device_id), "serio",