[PATCH] driver model updates (5/5)

Remove struct iobus.

There is a lot of duplication between struct device and struct iobus, both
in their members and the code in their interfaces. Waxing struct iobus
removes this duplication and makes things a bit simpler.

drivers/base/core.c

@@ -18,10 +18,7 @@
 # define DBG(x...)
 #endif
 
-static struct iobus device_root = {
-	bus_id: "root",
-	name:	"Logical System Root",
-};
+static struct device * device_root;
 
 int (*platform_notify)(struct device * dev) = NULL;
 int (*platform_notify_remove)(struct device * dev) = NULL;
@@ -29,9 +26,6 @@ int (*platform_notify_remove)(struct device * dev) = NULL;
 extern int device_make_dir(struct device * dev);
 extern void device_remove_dir(struct device * dev);
 
-extern int iobus_make_dir(struct iobus * iobus);
-extern void iobus_remove_dir(struct iobus * iobus);
-
 static spinlock_t device_lock;
 
 /**
@@ -48,19 +42,23 @@ int device_register(struct device *dev)
 
 	if (!dev || !strlen(dev->bus_id))
 		return -EINVAL;
-	BUG_ON(!dev->parent);
 
 	spin_lock(&device_lock);
 	INIT_LIST_HEAD(&dev->node);
+	INIT_LIST_HEAD(&dev->children);
 	spin_lock_init(&dev->lock);
 	atomic_set(&dev->refcount,2);
 
-	get_iobus(dev->parent);
-	list_add_tail(&dev->node,&dev->parent->devices);
+	if (dev != device_root) {
+		if (!dev->parent)
+			dev->parent = device_root;
+		get_device(dev->parent);
+		list_add_tail(&dev->node,&dev->parent->children);
+	}
 	spin_unlock(&device_lock);
 
-	DBG("DEV: registering device: ID = '%s', name = %s, parent = %s\n",
-	    dev->bus_id, dev->name, parent->bus_id);
+	DBG("DEV: registering device: ID = '%s', name = %s\n",
+	    dev->bus_id, dev->name);
 
 	if ((error = device_make_dir(dev)))
 		goto register_done;
@@ -71,8 +69,8 @@ int device_register(struct device *dev)
 
  register_done:
 	put_device(dev);
-	if (error)
-		put_iobus(dev->parent);
+	if (error && dev->parent)
+		put_device(dev->parent);
 	return error;
 }
 
@@ -101,9 +99,6 @@ void put_device(struct device * dev)
 	/* remove the driverfs directory */
 	device_remove_dir(dev);
 
-	if (dev->subordinate)
-		iobus_remove_dir(dev->subordinate);
-
 	/* Notify the platform of the removal, in case they
 	 * need to do anything...
 	 */
@@ -117,70 +112,18 @@ void put_device(struct device * dev)
 	if (dev->driver && dev->driver->remove)
 		dev->driver->remove(dev,REMOVE_FREE_RESOURCES);
 
-	put_iobus(dev->parent);
-}
-
-int iobus_register(struct iobus *bus)
-{
-	int error;
-
-	if (!bus || !strlen(bus->bus_id))
-		return -EINVAL;
-	
-	spin_lock(&device_lock);
-	atomic_set(&bus->refcount,2);
-	spin_lock_init(&bus->lock);
-	INIT_LIST_HEAD(&bus->node);
-	INIT_LIST_HEAD(&bus->devices);
-	INIT_LIST_HEAD(&bus->children);
-
-	if (bus != &device_root) {
-		if (!bus->parent)
-			bus->parent = &device_root;
-		get_iobus(bus->parent);
-		list_add_tail(&bus->node,&bus->parent->children);
-	}
-	spin_unlock(&device_lock);
-
-	DBG("DEV: registering bus. ID = '%s' name = '%s' parent = %p\n",
-	    bus->bus_id,bus->name,bus->parent);
-
-	error = iobus_make_dir(bus);
-
-	put_iobus(bus);
-	if (error && bus->parent)
-		put_iobus(bus->parent);
-	return error;
-}
-
-/**
- * iobus_unregister - remove bus and children from device tree
- * @bus:	pointer to bus structure
- *
- * Remove device from parent's list of children and decrement
- * reference count on controlling device. That should take care of
- * the rest of the cleanup.
- */
-void put_iobus(struct iobus * iobus)
-{
-	if (!atomic_dec_and_lock(&iobus->refcount,&device_lock))
-		return;
-	list_del_init(&iobus->node);
-	spin_unlock(&device_lock);
-
-	if (!list_empty(&iobus->devices) ||
-	    !list_empty(&iobus->children))
-		BUG();
-
-	put_iobus(iobus->parent);
-	/* unregister itself */
-	put_device(iobus->self);
+	put_device(dev->parent);
 }
 
 static int __init device_init_root(void)
 {
-	/* initialize parent bus lists */
-	return iobus_register(&device_root);
+	device_root = kmalloc(sizeof(*device_root),GFP_KERNEL);
+	if (!device_root)
+		return -ENOMEM;
+	memset(device_root,0,sizeof(*device_root));
+	strcpy(device_root->bus_id,"root");
+	strcpy(device_root->name,"System Root");
+	return device_register(device_root);
 }
 
 static int __init device_driver_init(void)
@@ -212,5 +155,3 @@ subsys_initcall(device_driver_init);
 
 EXPORT_SYMBOL(device_register);
 EXPORT_SYMBOL(put_device);
-EXPORT_SYMBOL(iobus_register);
-EXPORT_SYMBOL(put_iobus);

drivers/base/fs.c

@@ -104,28 +104,6 @@ int device_make_dir(struct device * dev)
 	return 0;
 }
 
-void iobus_remove_dir(struct iobus * iobus)
-{
-	if (iobus)
-		driverfs_remove_dir(&iobus->dir);
-}
-
-int iobus_make_dir(struct iobus * iobus)
-{
-	struct driver_dir_entry * parent = NULL;
-	int error;
-
-	INIT_LIST_HEAD(&iobus->dir.files);
-	iobus->dir.mode = (S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO);
-	iobus->dir.name = iobus->bus_id;
-
-	if (iobus->parent)
-		parent = &iobus->parent->dir;
-
-	error = driverfs_create_dir(&iobus->dir,parent);
-	return error;
-}
-
 EXPORT_SYMBOL(device_create_file);
 EXPORT_SYMBOL(device_remove_file);
 

drivers/pci/pci.c

@@ -1086,13 +1086,7 @@ struct pci_bus * __devinit pci_add_new_bus(struct pci_bus *parent, struct pci_de
 	child->parent = parent;
 	child->ops = parent->ops;
 	child->sysdata = parent->sysdata;
-
-	/* init generic fields */
-	child->iobus.self = &dev->dev;
-	child->iobus.parent = &parent->iobus;
-	dev->dev.subordinate = &child->iobus;
-
-	strcpy(child->iobus.name,dev->dev.name);
+	child->dev = &dev->dev;
 
 	/*
 	 * Set up the primary, secondary and subordinate
@@ -1361,16 +1355,11 @@ unsigned int __devinit pci_do_scan_bus(struct pci_bus *bus)
 	DBG("Scanning bus %02x\n", bus->number);
 	max = bus->secondary;
 
-	/* we should know for sure what the bus number is, so set the bus ID
-	 * for the bus and make sure it's registered in the device tree */
-	sprintf(bus->iobus.bus_id,"pci%d",bus->number);
-	iobus_register(&bus->iobus);
-
 	/* Create a device template */
 	memset(&dev0, 0, sizeof(dev0));
 	dev0.bus = bus;
 	dev0.sysdata = bus->sysdata;
-	dev0.dev.parent = &bus->iobus;
+	dev0.dev.parent = bus->dev;
 	dev0.dev.driver = &pci_device_driver;
 
 	/* Go find them, Rover! */
@@ -1430,9 +1419,11 @@ struct pci_bus * __devinit  pci_alloc_primary_bus(int bus)
 		return NULL;
 	list_add_tail(&b->node, &pci_root_buses);
 
-	sprintf(b->iobus.bus_id,"pci%d",bus);
-	strcpy(b->iobus.name,"Host/PCI Bridge");
-	iobus_register(&b->iobus);
+	b->dev = kmalloc(sizeof(*(b->dev)),GFP_KERNEL);
+	memset(b->dev,0,sizeof(*(b->dev)));
+	sprintf(b->dev->bus_id,"pci%d",bus);
+	strcpy(b->dev->name,"Host/PCI Bridge");
+	device_register(b->dev);
 
 	b->number = b->secondary = bus;
 	b->resource[0] = &ioport_resource;

include/linux/device.h

@@ -66,10 +66,8 @@ struct device_driver {
 
 struct device {
 	struct list_head node;		/* node in sibling list */
-	struct iobus	*parent;	/* parent bus */
-
-	struct iobus	*subordinate;	/* only valid if this device is a
-					   bridge device */
+	struct list_head children;
+	struct device 	* parent;
 
 	char	name[DEVICE_NAME_SIZE];	/* descriptive ascii string */
 	char	bus_id[BUS_ID_SIZE];	/* position on parent bus */
@@ -113,36 +111,12 @@ struct iobus_driver {
 	int	(*add_device)	(struct iobus*, char*);
 };
 
-struct iobus {
-	spinlock_t	lock;		/* lock for bus */
-	atomic_t	refcount;
-
-	struct list_head node;		/* node in sibling list */
-	struct iobus *parent;		/* parent bus */
-	struct list_head children;	/* children buses */
-	struct list_head devices;	/* children devices */
-
-	struct device *self;		/* pointer to controlling device */
-	struct driver_dir_entry	dir;	/* driverfs directory */
-
-	char	name[DEVICE_NAME_SIZE];
-	char	bus_id[BUS_ID_SIZE];
-
-	struct	iobus_driver *driver;	/* bus operations */
-};
-
 static inline struct device *
 list_to_dev(struct list_head *node)
 {
 	return list_entry(node, struct device, node);
 }
 
-static inline struct iobus *
-list_to_iobus(const struct list_head *node)
-{
-	return list_entry(node, struct iobus, node);
-}
-
 /*
  * High level routines for use by the bus drivers
  */
@@ -189,22 +163,4 @@ static inline void get_device(struct device * dev)
 
 extern void put_device(struct device * dev);
 
-static inline void lock_iobus(struct iobus * iobus)
-{
-	spin_lock(&iobus->lock);
-}
-
-static inline void unlock_iobus(struct iobus * iobus)
-{
-	spin_unlock(&iobus->lock);
-}
-
-static inline void get_iobus(struct iobus * iobus)
-{
-	BUG_ON(!atomic_read(&iobus->refcount));
-	atomic_inc(&iobus->refcount);
-}
-
-extern void put_iobus(struct iobus * iobus);
-
 #endif /* _DEVICE_H_ */

include/linux/pci.h

@@ -432,8 +432,7 @@ struct pci_bus {
 	unsigned char	productver;	/* product version */
 	unsigned char	checksum;	/* if zero - checksum passed */
 	unsigned char	pad1;
-
-	struct iobus	iobus;		/* Generic device interface */
+	struct	device	* dev;
 };
 
 #define pci_bus_b(n) list_entry(n, struct pci_bus, node)