[patch 02/14] cio: Introduce modalias for css bus.

From: Martin Schwidefsky
Date: Tue Jun 03 2008 - 13:08:26 EST


From: Cornelia Huck <cornelia.huck@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

Documentation/ABI/testing/sysfs-bus-css | 35 ++++++++++++++++
drivers/s390/cio/cio.h | 1
drivers/s390/cio/css.c | 69 +++++++++++++++++++++++++++++---
drivers/s390/cio/css.h | 2
drivers/s390/cio/device.c | 47 ++++++++++++++-------
include/linux/mod_devicetable.h | 9 ++++
scripts/mod/file2alias.c | 12 +++++
7 files changed, 151 insertions(+), 24 deletions(-)

Index: quilt-2.6/Documentation/ABI/testing/sysfs-bus-css
===================================================================
--- /dev/null
+++ quilt-2.6/Documentation/ABI/testing/sysfs-bus-css
@@ -0,0 +1,35 @@
+What: /sys/bus/css/devices/.../type
+Date: March 2008
+Contact: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
+ linux-s390@xxxxxxxxxxxxxxx
+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@xxxxxxxxxx>
+ linux-s390@xxxxxxxxxxxxxxx
+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@xxxxxxxxxx>
+ linux-s390@xxxxxxxxxxxxxxx
+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@xxxxxxxxxx>
+ linux-s390@xxxxxxxxxxxxxxx
+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
Index: quilt-2.6/drivers/s390/cio/cio.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/cio.h
+++ quilt-2.6/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"
Index: quilt-2.6/drivers/s390/cio/css.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/css.c
+++ quilt-2.6/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@xxxxxxxxxx)
* Cornelia Huck (cornelia.huck@xxxxxxxxxx)
*/
@@ -210,6 +209,41 @@ void css_update_ssd_info(struct subchann
}
}

+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(struc
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(struc
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 *
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,
};

/**
Index: quilt-2.6/drivers/s390/cio/css.h
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/css.h
+++ quilt-2.6/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
Index: quilt-2.6/drivers/s390/cio/device.c
===================================================================
--- quilt-2.6.orig/drivers/s390/cio/device.c
+++ quilt-2.6/drivers/s390/cio/device.c
@@ -585,19 +585,14 @@ static DEVICE_ATTR(modalias, 0444, modal
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 su

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 su
*/
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 su
}
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 su
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
ccw_device_unregister(cdev);
put_device(&cdev->dev);
kfree(sch->private);
+ sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
return 0;
}

Index: quilt-2.6/include/linux/mod_devicetable.h
===================================================================
--- quilt-2.6.orig/include/linux/mod_devicetable.h
+++ quilt-2.6/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 */

Index: quilt-2.6/scripts/mod/file2alias.c
===================================================================
--- quilt-2.6.orig/scripts/mod/file2alias.c
+++ quilt-2.6/scripts/mod/file2alias.c
@@ -304,6 +304,14 @@ static int do_ap_entry(const char *filen
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 *m
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",

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/