Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

ab86e576 · Linus Torvalds <[email protected]> · 2009-09-16 08:27:10 -07:00

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev
  debugfs: Modify default debugfs directory for debugging pktcdvd.
  debugfs: Modified default dir of debugfs for debugging UHCI.
  debugfs: Change debugfs directory of IWMC3200
  debugfs: Change debuhgfs directory of trace-events-sample.h
  debugfs: Fix mount directory of debugfs by default in events.txt
  hpilo: add poll f_op
  hpilo: add interrupt handler
  hpilo: staging for interrupt handling
  driver core: platform_device_add_data(): use kmemdup()
  Driver core: Add support for compatibility classes
  uio: add generic driver for PCI 2.3 devices
  driver-core: move dma-coherent.c from kernel to driver/base
  mem_class: fix bug
  mem_class: use minor as index instead of searching the array
  driver model: constify attribute groups
  UIO: remove 'default n' from Kconfig
  Driver core: Add accessor for device platform data
  Driver core: move dev_get/set_drvdata to drivers/base/dd.c
  Driver core: add new device to bus's list before probing

Commit: ab86e5765d41a5eb4239a1c04d613db87bea5ed8
Parents: 7ea61767 · 2b2af54a

Merge commit. Changes below are compared with the first parent: 7ea61767.

Changes

59 files changed · +1287 −239

File	Status	Add	Del	Content
Documentation/DocBook/uio-howto.tmpl	modified	+163	−0	View file
Documentation/trace/events.txt	modified	+12	−12	View file
MAINTAINERS	modified	+7	−0	View file
block/genhd.c	modified	+1	−1	View file
drivers/base/Kconfig	modified	+25	−0	View file
drivers/base/Makefile	modified	+2	−0	View file
drivers/base/base.h	modified	+12	−1	View file
drivers/base/bus.c	modified	+10	−13	View file
drivers/base/class.c	modified	+87	−0	View file
drivers/base/core.c	modified	+20	−9	View file
drivers/base/dd.c	modified	+29	−2	View file
drivers/base/devtmpfs.c	added	+367	−0	View file
kernel/dma-coherent.c → drivers/base/dma-coherent.c	renamed	+0	−0	View file
drivers/base/driver.c	modified	+2	−2	View file
drivers/base/init.c	modified	+1	−0	View file
drivers/base/platform.c	modified	+4	−4	View file
drivers/block/cciss.c	modified	+1	−1	View file
drivers/block/pktcdvd.c	modified	+1	−1	View file
drivers/char/mem.c	modified	+40	−42	View file
drivers/firewire/core-device.c	modified	+1	−1	View file
drivers/firmware/dmi-id.c	modified	+1	−1	View file
drivers/infiniband/hw/ehca/ehca_main.c	modified	+1	−1	View file
drivers/infiniband/hw/ipath/ipath_kernel.h	modified	+1	−1	View file
drivers/infiniband/hw/ipath/ipath_sysfs.c	modified	+1	−1	View file
drivers/input/input.c	modified	+1	−1	View file
drivers/misc/enclosure.c	modified	+2	−2	View file
drivers/misc/hpilo.c	modified	+203	−87	View file
drivers/misc/hpilo.h	modified	+7	−1	View file
drivers/mmc/core/mmc.c	modified	+1	−1	View file
drivers/mmc/core/sd.c	modified	+1	−1	View file
drivers/mtd/mtdcore.c	modified	+1	−1	View file
drivers/net/wireless/iwmc3200wifi/Kconfig	modified	+3	−3	View file
drivers/s390/cio/css.c	modified	+1	−1	View file
drivers/s390/cio/device.c	modified	+1	−1	View file
drivers/s390/net/netiucv.c	modified	+1	−1	View file
drivers/scsi/scsi_priv.h	modified	+1	−1	View file
drivers/scsi/scsi_sysfs.c	modified	+2	−2	View file
drivers/uio/Kconfig	modified	+10	−5	View file
drivers/uio/Makefile	modified	+1	−0	View file
drivers/uio/uio_pci_generic.c	added	+207	−0	View file
drivers/usb/core/endpoint.c	modified	+1	−1	View file
drivers/usb/core/sysfs.c	modified	+2	−2	View file
drivers/usb/core/usb.h	modified	+2	−2	View file
drivers/usb/host/uhci-hcd.c	modified	+1	−1	View file
drivers/uwb/lc-dev.c	modified	+1	−1	View file
fs/partitions/check.c	modified	+1	−1	View file
include/linux/attribute_container.h	modified	+1	−1	View file
include/linux/device.h	modified	+30	−15	View file
include/linux/netdevice.h	modified	+1	−1	View file
include/linux/pci_regs.h	modified	+1	−0	View file
include/linux/shmem_fs.h	modified	+3	−0	View file
include/linux/transport_class.h	modified	+1	−1	View file
init/do_mounts.c	modified	+1	−1	View file
init/main.c	modified	+2	−0	View file
kernel/Makefile	modified	+0	−1	View file
mm/shmem.c	modified	+3	−6	View file
net/bluetooth/hci_sysfs.c	modified	+2	−2	View file
net/core/net-sysfs.c	modified	+1	−1	View file
samples/trace_events/trace-events-sample.h	modified	+1	−1	View file

Only the first 600 diff lines are shown. Download the complete patch.

Documentation/DocBook/uio-howto.tmpl

View file

diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index 8f6e3b2..4d4ce0e 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -25,6 +25,10 @@
 	<year>2006-2008</year>
 	<holder>Hans-Jürgen Koch.</holder>
 </copyright>
+<copyright>
+	<year>2009</year>
+	<holder>Red Hat Inc, Michael S. Tsirkin ([email protected])</holder>
+</copyright>
 
 <legalnotice>
 <para>
@@ -42,6 +46,13 @@ GPL version 2.
 
 <revhistory>
 	<revision>
+	<revnumber>0.9</revnumber>
+	<date>2009-07-16</date>
+	<authorinitials>mst</authorinitials>
+	<revremark>Added generic pci driver
+		</revremark>
+	</revision>
+	<revision>
 	<revnumber>0.8</revnumber>
 	<date>2008-12-24</date>
 	<authorinitials>hjk</authorinitials>
@@ -809,6 +820,158 @@ framework to set up sysfs files for this region. Simply leave it alone.
 
 </chapter>
 
+<chapter id="uio_pci_generic" xreflabel="Using Generic driver for PCI cards">
+<?dbhtml filename="uio_pci_generic.html"?>
+<title>Generic PCI UIO driver</title>
+	<para>
+	The generic driver is a kernel module named uio_pci_generic.
+	It can work with any device compliant to PCI 2.3 (circa 2002) and
+	any compliant PCI Express device. Using this, you only need to
+        write the userspace driver, removing the need to write
+        a hardware-specific kernel module.
+	</para>
+
+<sect1 id="uio_pci_generic_binding">
+<title>Making the driver recognize the device</title>
+	<para>
+Since the driver does not declare any device ids, it will not get loaded
+automatically and will not automatically bind to any devices, you must load it
+and allocate id to the driver yourself. For example:
+	<programlisting>
+ modprobe uio_pci_generic
+ echo &quot;8086 10f5&quot; &gt; /sys/bus/pci/drivers/uio_pci_generic/new_id
+	</programlisting>
+	</para>
+	<para>
+If there already is a hardware specific kernel driver for your device, the
+generic driver still won't bind to it, in this case if you want to use the
+generic driver (why would you?) you'll have to manually unbind the hardware
+specific driver and bind the generic driver, like this:
+	<programlisting>
+    echo -n 0000:00:19.0 &gt; /sys/bus/pci/drivers/e1000e/unbind
+    echo -n 0000:00:19.0 &gt; /sys/bus/pci/drivers/uio_pci_generic/bind
+	</programlisting>
+	</para>
+	<para>
+You can verify that the device has been bound to the driver
+by looking for it in sysfs, for example like the following:
+	<programlisting>
+    ls -l /sys/bus/pci/devices/0000:00:19.0/driver
+	</programlisting>
+Which if successful should print
+	<programlisting>
+  .../0000:00:19.0/driver -&gt; ../../../bus/pci/drivers/uio_pci_generic
+	</programlisting>
+Note that the generic driver will not bind to old PCI 2.2 devices.
+If binding the device failed, run the following command:
+	<programlisting>
+  dmesg
+	</programlisting>
+and look in the output for failure reasons
+	</para>
+</sect1>
+
+<sect1 id="uio_pci_generic_internals">
+<title>Things to know about uio_pci_generic</title>
+	<para>
+Interrupts are handled using the Interrupt Disable bit in the PCI command
+register and Interrupt Status bit in the PCI status register.  All devices
+compliant to PCI 2.3 (circa 2002) and all compliant PCI Express devices should
+support these bits.  uio_pci_generic detects this support, and won't bind to
+devices which do not support the Interrupt Disable Bit in the command register.
+	</para>
+	<para>
+On each interrupt, uio_pci_generic sets the Interrupt Disable bit.
+This prevents the device from generating further interrupts
+until the bit is cleared. The userspace driver should clear this
+bit before blocking and waiting for more interrupts.
+	</para>
+</sect1>
+<sect1 id="uio_pci_generic_userspace">
+<title>Writing userspace driver using uio_pci_generic</title>
+	<para>
+Userspace driver can use pci sysfs interface, or the
+libpci libray that wraps it, to talk to the device and to
+re-enable interrupts by writing to the command register.
+	</para>
+</sect1>
+<sect1 id="uio_pci_generic_example">
+<title>Example code using uio_pci_generic</title>
+	<para>
+Here is some sample userspace driver code using uio_pci_generic:
+<programlisting>
+#include &lt;stdlib.h&gt;
+#include &lt;stdio.h&gt;
+#include &lt;unistd.h&gt;
+#include &lt;sys/types.h&gt;
+#include &lt;sys/stat.h&gt;
+#include &lt;fcntl.h&gt;
+#include &lt;errno.h&gt;
+
+int main()
+{
+	int uiofd;
+	int configfd;
+	int err;
+	int i;
+	unsigned icount;
+	unsigned char command_high;
+
+	uiofd = open(&quot;/dev/uio0&quot;, O_RDONLY);
+	if (uiofd &lt; 0) {
+		perror(&quot;uio open:&quot;);
+		return errno;
+	}
+	configfd = open(&quot;/sys/class/uio/uio0/device/config&quot;, O_RDWR);
+	if (uiofd &lt; 0) {
+		perror(&quot;config open:&quot;);
+		return errno;
+	}
+
+	/* Read and cache command value */
+	err = pread(configfd, &amp;command_high, 1, 5);
+	if (err != 1) {
+		perror(&quot;command config read:&quot;);
+		return errno;
+	}
+	command_high &amp;= ~0x4;
+
+	for(i = 0;; ++i) {
+		/* Print out a message, for debugging. */
+		if (i == 0)
+			fprintf(stderr, &quot;Started uio test driver.\n&quot;);
+		else
+			fprintf(stderr, &quot;Interrupts: %d\n&quot;, icount);
+
+		/****************************************/
+		/* Here we got an interrupt from the
+		   device. Do something to it. */
+		/****************************************/
+
+		/* Re-enable interrupts. */
+		err = pwrite(configfd, &amp;command_high, 1, 5);
+		if (err != 1) {
+			perror(&quot;config write:&quot;);
+			break;
+		}
+
+		/* Wait for next interrupt. */
+		err = read(uiofd, &amp;icount, 4);
+		if (err != 4) {
+			perror(&quot;uio read:&quot;);
+			break;
+		}
+
+	}
+	return errno;
+}
+
+</programlisting>
+	</para>
+</sect1>
+
+</chapter>
+
 <appendix id="app1">
 <title>Further information</title>
 <itemizedlist>

Documentation/trace/events.txt

View file

diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index 2bcc8d4..90e8b33 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -22,12 +22,12 @@ tracing information should be printed.
 ---------------------------------
 
 The events which are available for tracing can be found in the file
-/debug/tracing/available_events.
+/sys/kernel/debug/tracing/available_events.
 
 To enable a particular event, such as 'sched_wakeup', simply echo it
-to /debug/tracing/set_event. For example:
+to /sys/kernel/debug/tracing/set_event. For example:
 
-	# echo sched_wakeup >> /debug/tracing/set_event
+	# echo sched_wakeup >> /sys/kernel/debug/tracing/set_event
 
 [ Note: '>>' is necessary, otherwise it will firstly disable
   all the events. ]
@@ -35,15 +35,15 @@ to /debug/tracing/set_event. For example:
 To disable an event, echo the event name to the set_event file prefixed
 with an exclamation point:
 
-	# echo '!sched_wakeup' >> /debug/tracing/set_event
+	# echo '!sched_wakeup' >> /sys/kernel/debug/tracing/set_event
 
 To disable all events, echo an empty line to the set_event file:
 
-	# echo > /debug/tracing/set_event
+	# echo > /sys/kernel/debug/tracing/set_event
 
 To enable all events, echo '*:*' or '*:' to the set_event file:
 
-	# echo *:* > /debug/tracing/set_event
+	# echo *:* > /sys/kernel/debug/tracing/set_event
 
 The events are organized into subsystems, such as ext4, irq, sched,
 etc., and a full event name looks like this: <subsystem>:<event>.  The
@@ -52,29 +52,29 @@ file.  All of the events in a subsystem can be specified via the syntax
 "<subsystem>:*"; for example, to enable all irq events, you can use the
 command:
 
-	# echo 'irq:*' > /debug/tracing/set_event
+	# echo 'irq:*' > /sys/kernel/debug/tracing/set_event
 
 2.2 Via the 'enable' toggle
 ---------------------------
 
-The events available are also listed in /debug/tracing/events/ hierarchy
+The events available are also listed in /sys/kernel/debug/tracing/events/ hierarchy
 of directories.
 
 To enable event 'sched_wakeup':
 
-	# echo 1 > /debug/tracing/events/sched/sched_wakeup/enable
+	# echo 1 > /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable
 
 To disable it:
 
-	# echo 0 > /debug/tracing/events/sched/sched_wakeup/enable
+	# echo 0 > /sys/kernel/debug/tracing/events/sched/sched_wakeup/enable
 
 To enable all events in sched subsystem:
 
-	# echo 1 > /debug/tracing/events/sched/enable
+	# echo 1 > /sys/kernel/debug/tracing/events/sched/enable
 
 To eanble all events:
 
-	# echo 1 > /debug/tracing/events/enable
+	# echo 1 > /sys/kernel/debug/tracing/events/enable
 
 When reading one of these enable files, there are four results:
 

MAINTAINERS

View file

diff --git a/MAINTAINERS b/MAINTAINERS
index 64b9e44..9117b65 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2218,6 +2218,13 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git
 S:	Maintained
 F:	include/asm-generic
 
+GENERIC UIO DRIVER FOR PCI DEVICES
+M:	Michael S. Tsirkin <[email protected]>
+L:	[email protected]
+L:	[email protected]
+S:	Supported
+F:	drivers/uio/uio_pci_generic.c
+
 GFS2 FILE SYSTEM
 M:	Steven Whitehouse <[email protected]>
 L:	[email protected]

block/genhd.c

View file

diff --git a/block/genhd.c b/block/genhd.c
index 5b76bf5..2ad91dd 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -903,7 +903,7 @@ static struct attribute_group disk_attr_group = {
 	.attrs = disk_attrs,
 };
 
-static struct attribute_group *disk_attr_groups[] = {
+static const struct attribute_group *disk_attr_groups[] = {
 	&disk_attr_group,
 	NULL
 };

drivers/base/Kconfig

View file

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 8f006f9..ee37727 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -8,6 +8,31 @@ config UEVENT_HELPER_PATH
 	  Path to uevent helper program forked by the kernel for
 	  every uevent.
 
+config DEVTMPFS
+	bool "Create a kernel maintained /dev tmpfs (EXPERIMENTAL)"
+	depends on HOTPLUG && SHMEM && TMPFS
+	help
+	  This creates a tmpfs filesystem, and mounts it at bootup
+	  and mounts it at /dev. The kernel driver core creates device
+	  nodes for all registered devices in that filesystem. All device
+	  nodes are owned by root and have the default mode of 0600.
+	  Userspace can add and delete the nodes as needed. This is
+	  intended to simplify bootup, and make it possible to delay
+	  the initial coldplug at bootup done by udev in userspace.
+	  It should also provide a simpler way for rescue systems
+	  to bring up a kernel with dynamic major/minor numbers.
+	  Meaningful symlinks, permissions and device ownership must
+	  still be handled by userspace.
+	  If unsure, say N here.
+
+config DEVTMPFS_MOUNT
+	bool "Automount devtmpfs at /dev"
+	depends on DEVTMPFS
+	help
+	  This will mount devtmpfs at /dev if the kernel mounts the root
+	  filesystem. It will not affect initramfs based mounting.
+	  If unsure, say N here.
+
 config STANDALONE
 	bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
 	default y

drivers/base/Makefile

View file

diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index b5b8ba5..c12c7f2 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -4,8 +4,10 @@ obj-y			:= core.o sys.o bus.o dd.o \
 			   driver.o class.o platform.o \
 			   cpu.o firmware.o init.o map.o devres.o \
 			   attribute_container.o transport_class.o
+obj-$(CONFIG_DEVTMPFS)	+= devtmpfs.o
 obj-y			+= power/
 obj-$(CONFIG_HAS_DMA)	+= dma-mapping.o
+obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
 obj-$(CONFIG_ISA)	+= isa.o
 obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
 obj-$(CONFIG_NUMA)	+= node.o

drivers/base/base.h

View file

diff --git a/drivers/base/base.h b/drivers/base/base.h
index b528145..2ca7f5b 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -70,6 +70,8 @@ struct class_private {
  * @knode_parent - node in sibling list
  * @knode_driver - node in driver list
  * @knode_bus - node in bus list
+ * @driver_data - private pointer for driver specific info.  Will turn into a
+ * list soon.
  * @device - pointer back to the struct class that this structure is
  * associated with.
  *
@@ -80,6 +82,7 @@ struct device_private {
 	struct klist_node knode_parent;
 	struct klist_node knode_driver;
 	struct klist_node knode_bus;
+	void *driver_data;
 	struct device *device;
 };
 #define to_device_private_parent(obj)	\
@@ -89,6 +92,8 @@ struct device_private {
 #define to_device_private_bus(obj)	\
 	container_of(obj, struct device_private, knode_bus)
 
+extern int device_private_init(struct device *dev);
+
 /* initialisation functions */
 extern int devices_init(void);
 extern int buses_init(void);
@@ -104,7 +109,7 @@ extern int system_bus_init(void);
 extern int cpu_dev_init(void);
 
 extern int bus_add_device(struct device *dev);
-extern void bus_attach_device(struct device *dev);
+extern void bus_probe_device(struct device *dev);
 extern void bus_remove_device(struct device *dev);
 
 extern int bus_add_driver(struct device_driver *drv);
@@ -134,3 +139,9 @@ static inline void module_add_driver(struct module *mod,
 				     struct device_driver *drv) { }
 static inline void module_remove_driver(struct device_driver *drv) { }
 #endif
+
+#ifdef CONFIG_DEVTMPFS
+extern int devtmpfs_init(void);
+#else
+static inline int devtmpfs_init(void) { return 0; }
+#endif

drivers/base/bus.c

View file

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 4b04a15..973bf2a 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -459,8 +459,9 @@ static inline void remove_deprecated_bus_links(struct device *dev) { }
  * bus_add_device - add device to bus
  * @dev: device being added
  *
+ * - Add device's bus attributes.
+ * - Create links to device's bus.
  * - Add the device to its bus's list of devices.
- * - Create link to device's bus.
  */
 int bus_add_device(struct device *dev)
 {
@@ -483,6 +484,7 @@ int bus_add_device(struct device *dev)
 		error = make_deprecated_bus_links(dev);
 		if (error)
 			goto out_deprecated;
+		klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
 	}
 	return 0;
 
@@ -498,24 +500,19 @@ out_put:
 }
 
 /**
- * bus_attach_device - add device to bus
- * @dev: device tried to attach to a driver
+ * bus_probe_device - probe drivers for a new device
+ * @dev: device to probe
  *
- * - Add device to bus's list of devices.
- * - Try to attach to driver.
+ * - Automatically probe for a driver if the bus allows it.
  */
-void bus_attach_device(struct device *dev)
+void bus_probe_device(struct device *dev)
 {
 	struct bus_type *bus = dev->bus;
-	int ret = 0;
+	int ret;
 
-	if (bus) {
-		if (bus->p->drivers_autoprobe)
-			ret = device_attach(dev);
+	if (bus && bus->p->drivers_autoprobe) {
+		ret = device_attach(dev);
 		WARN_ON(ret < 0);
-		if (ret >= 0)
-			klist_add_tail(&dev->p->knode_bus,
-				       &bus->p->klist_devices);
 	}
 }
 

drivers/base/class.c

View file

diff --git a/drivers/base/class.c b/drivers/base/class.c
index eb85e43..161746d 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -488,6 +488,93 @@ void class_interface_unregister(struct class_interface *class_intf)
 	class_put(parent);
 }
 
+struct class_compat {
+	struct kobject *kobj;
+};
+
+/**
+ * class_compat_register - register a compatibility class
+ * @name: the name of the class
+ *
+ * Compatibility class are meant as a temporary user-space compatibility
+ * workaround when converting a family of class devices to a bus devices.
+ */
+struct class_compat *class_compat_register(const char *name)
+{
+	struct class_compat *cls;
+
+	cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL);
+	if (!cls)
+		return NULL;
+	cls->kobj = kobject_create_and_add(name, &class_kset->kobj);
+	if (!cls->kobj) {
+		kfree(cls);
+		return NULL;
+	}
+	return cls;
+}
+EXPORT_SYMBOL_GPL(class_compat_register);
+
+/**
+ * class_compat_unregister - unregister a compatibility class
+ * @cls: the class to unregister
+ */
+void class_compat_unregister(struct class_compat *cls)
+{
+	kobject_put(cls->kobj);
+	kfree(cls);
+}
+EXPORT_SYMBOL_GPL(class_compat_unregister);
+
+/**
+ * class_compat_create_link - create a compatibility class device link to
+ *			      a bus device
+ * @cls: the compatibility class
+ * @dev: the target bus device
+ * @device_link: an optional device to which a "device" link should be created
+ */
+int class_compat_create_link(struct class_compat *cls, struct device *dev,
+			     struct device *device_link)
+{
+	int error;
+
+	error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev));
+	if (error)
+		return error;
+
+	/*
+	 * Optionally add a "device" link (typically to the parent), as a
+	 * class device would have one and we want to provide as much
+	 * backwards compatibility as possible.
+	 */
+	if (device_link) {
+		error = sysfs_create_link(&dev->kobj, &device_link->kobj,
+					  "device");
+		if (error)
+			sysfs_remove_link(cls->kobj, dev_name(dev));
+	}
+
+	return error;
+}
+EXPORT_SYMBOL_GPL(class_compat_create_link);
+
+/**
+ * class_compat_remove_link - remove a compatibility class device link to
+ *			      a bus device
+ * @cls: the compatibility class
+ * @dev: the target bus device
+ * @device_link: an optional device to which a "device" link was previously
+ * 		 created
+ */
+void class_compat_remove_link(struct class_compat *cls, struct device *dev,
+			      struct device *device_link)
+{
+	if (device_link)
+		sysfs_remove_link(&dev->kobj, "device");
+	sysfs_remove_link(cls->kobj, dev_name(dev));
+}
+EXPORT_SYMBOL_GPL(class_compat_remove_link);
+
 int __init classes_init(void)
 {
 	class_kset = kset_create_and_add("class", NULL, NULL);

drivers/base/core.c

View file

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 7ecb193..390e664 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -341,7 +341,7 @@ static void device_remove_attributes(struct device *dev,
 }
 
 static int device_add_groups(struct device *dev,
-			     struct attribute_group **groups)
+			     const struct attribute_group **groups)
 {
 	int error = 0;
 	int i;
@@ -361,7 +361,7 @@ static int device_add_groups(struct device *dev,
 }
 
 static void device_remove_groups(struct device *dev,
-				 struct attribute_group **groups)
+				 const struct attribute_group **groups)
 {
 	int i;
 
@@ -843,6 +843,17 @@ static void device_remove_sys_dev_entry(struct device *dev)
 	}
 }
 
+int device_private_init(struct device *dev)
+{
+	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
+	if (!dev->p)
+		return -ENOMEM;
+	dev->p->device = dev;
+	klist_init(&dev->p->klist_children, klist_children_get,
+		   klist_children_put);
+	return 0;
+}
+
 /**
  * device_add - add device to device hierarchy.
  * @dev: device.
@@ -868,14 +879,11 @@ int device_add(struct device *dev)
 	if (!dev)
 		goto done;
 
-	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
 	if (!dev->p) {
-		error = -ENOMEM;
-		goto done;
+		error = device_private_init(dev);
+		if (error)
+			goto done;
 	}
-	dev->p->device = dev;