of/device: Rework to use common platform_device_alloc() for allocating devices

The current code allocates and manages platform_devices created from
the device tree manually.  It also uses an unsafe shortcut for
allocating the platform_device and the resource table at the same
time. (which I added in the last rework; sorry).

This patch refactors the code to use platform_device_alloc() for
allocating new devices.  This reduces the amount of custom code
implemented by of_platform, eliminates the unsafe alloc trick, and has
the side benefit of letting the platform_bus code manage freeing the
device data and resources when the device is freed.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michal Simek <monstr@monstr.eu>

diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index 9b626cf..f62efdf 100644 (file)
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -162,13 +162,10 @@ static int ibmebus_create_device(struct device_node *dn)
        dev->dev.bus = &ibmebus_bus_type;
        dev->dev.archdata.dma_ops = &ibmebus_dma_ops;
 
-       ret = of_device_register(dev);
-       if (ret) {
-               of_device_free(dev);
-               return ret;
-       }
-
-       return 0;
+       ret = of_device_add(dev);
+       if (ret)
+               platform_device_put(dev);
+       return ret;
 }
 
 static int ibmebus_create_devices(const struct of_device_id *matches)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index c6c933f..2fff59c 100644 (file)
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -147,6 +147,7 @@ static void platform_device_release(struct device *dev)
        struct platform_object *pa = container_of(dev, struct platform_object,
                                                  pdev.dev);
 
+       of_device_node_put(&pa->pdev.dev);
        kfree(pa->pdev.dev.platform_data);
        kfree(pa->pdev.resource);
        kfree(pa);

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 92de0eb..45d8653 100644 (file)
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -81,29 +81,10 @@ struct device_attribute of_platform_device_attrs[] = {
        __ATTR_NULL
 };
 
-/**
- * of_release_dev - free an of device structure when all users of it are finished.
- * @dev: device that's been disconnected
- *
- * Will be called only by the device core when all users of this of device are
- * done.
- */
-void of_release_dev(struct device *dev)
-{
-       struct platform_device *ofdev;
-
-       ofdev = to_platform_device(dev);
-       of_node_put(ofdev->dev.of_node);
-       kfree(ofdev);
-}
-EXPORT_SYMBOL(of_release_dev);
-
-int of_device_register(struct platform_device *ofdev)
+int of_device_add(struct platform_device *ofdev)
 {
        BUG_ON(ofdev->dev.of_node == NULL);
 
-       device_initialize(&ofdev->dev);
-
        /* name and id have to be set so that the platform bus doesn't get
         * confused on matching */
        ofdev->name = dev_name(&ofdev->dev);
@@ -117,6 +98,12 @@ int of_device_register(struct platform_device *ofdev)
 
        return device_add(&ofdev->dev);
 }
+
+int of_device_register(struct platform_device *pdev)
+{
+       device_initialize(&pdev->dev);
+       return of_device_add(pdev);
+}
 EXPORT_SYMBOL(of_device_register);
 
 void of_device_unregister(struct platform_device *ofdev)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 30726c8..5b4a07f 100644 (file)
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -587,20 +587,23 @@ struct platform_device *of_device_alloc(struct device_node *np,
        int rc, i, num_reg = 0, num_irq;
        struct resource *res, temp_res;
 
-       /* First count how many resources are needed */
+       dev = platform_device_alloc("", -1);
+       if (!dev)
+               return NULL;
+
+       /* count the io and irq resources */
        while (of_address_to_resource(np, num_reg, &temp_res) == 0)
                num_reg++;
        num_irq = of_irq_count(np);
 
-       /* Allocate memory for both the struct device and the resource table */
-       dev = kzalloc(sizeof(*dev) + (sizeof(*res) * (num_reg + num_irq)),
-                     GFP_KERNEL);
-       if (!dev)
-               return NULL;
-       res = (struct resource *) &dev[1];
-
        /* Populate the resource table */
        if (num_irq || num_reg) {
+               res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
+               if (!res) {
+                       platform_device_put(dev);
+                       return NULL;
+               }
+
                dev->num_resources = num_reg + num_irq;
                dev->resource = res;
                for (i = 0; i < num_reg; i++, res++) {
@@ -615,7 +618,6 @@ struct platform_device *of_device_alloc(struct device_node *np,
        dev->dev.dma_mask = &dev->archdata.dma_mask;
 #endif
        dev->dev.parent = parent;
-       dev->dev.release = of_release_dev;
 
        if (bus_id)
                dev_set_name(&dev->dev, "%s", bus_id);
@@ -653,8 +655,8 @@ struct platform_device *of_platform_device_create(struct device_node *np,
         * to do such, possibly using a device notifier
         */
 
-       if (of_device_register(dev) != 0) {
-               of_device_free(dev);
+       if (of_device_add(dev) != 0) {
+               platform_device_put(dev);
                return NULL;
        }
 

diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index 835f85e..975d347 100644 (file)
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -27,20 +27,19 @@ static inline int of_driver_match_device(const struct device *dev,
 extern struct platform_device *of_dev_get(struct platform_device *dev);
 extern void of_dev_put(struct platform_device *dev);
 
+extern int of_device_add(struct platform_device *pdev);
 extern int of_device_register(struct platform_device *ofdev);
 extern void of_device_unregister(struct platform_device *ofdev);
-extern void of_release_dev(struct device *dev);
-
-static inline void of_device_free(struct platform_device *dev)
-{
-       of_release_dev(&dev->dev);
-}
 
 extern ssize_t of_device_get_modalias(struct device *dev,
                                        char *str, ssize_t len);
 
 extern int of_device_uevent(struct device *dev, struct kobj_uevent_env *env);
 
+static inline void of_device_node_put(struct device *dev)
+{
+       of_node_put(dev->of_node);
+}
 
 #else /* CONFIG_OF_DEVICE */
 
@@ -56,6 +55,8 @@ static inline int of_device_uevent(struct device *dev,
        return -ENODEV;
 }
 
+static inline void of_device_node_put(struct device *dev) { }
+
 #endif /* CONFIG_OF_DEVICE */
 
 #endif /* _LINUX_OF_DEVICE_H */