diff options
-rw-r--r-- | Documentation/driver-model/devres.txt | 2 | ||||
-rw-r--r-- | include/linux/ioport.h | 5 | ||||
-rw-r--r-- | kernel/resource.c | 73 |
3 files changed, 80 insertions, 0 deletions
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index df2613c73b1..77284ed9fea 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -249,6 +249,8 @@ IIO devm_iio_device_unregister() IO region + devm_request_resource() + devm_release_resource() devm_request_region() devm_request_mem_region() devm_release_region() diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 5e3a906cc08..21132ea7789 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -215,6 +215,11 @@ static inline int __deprecated check_region(resource_size_t s, /* Wrappers for managed devices */ struct device; + +extern int devm_request_resource(struct device *dev, struct resource *root, + struct resource *new); +extern void devm_release_resource(struct device *dev, struct resource *new); + #define devm_request_region(dev,start,n,name) \ __devm_request_region(dev, &ioport_resource, (start), (n), (name)) #define devm_request_mem_region(dev,start,n,name) \ diff --git a/kernel/resource.c b/kernel/resource.c index 3c2237ac32d..496e1e3547f 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1165,6 +1165,79 @@ int release_mem_region_adjustable(struct resource *parent, /* * Managed region resource */ +static void devm_resource_release(struct device *dev, void *ptr) +{ + struct resource **r = ptr; + + release_resource(*r); +} + +/** + * devm_request_resource() - request and reserve an I/O or memory resource + * @dev: device for which to request the resource + * @root: root of the resource tree from which to request the resource + * @new: descriptor of the resource to request + * + * This is a device-managed version of request_resource(). There is usually + * no need to release resources requested by this function explicitly since + * that will be taken care of when the device is unbound from its driver. + * If for some reason the resource needs to be released explicitly, because + * of ordering issues for example, drivers must call devm_release_resource() + * rather than the regular release_resource(). + * + * When a conflict is detected between any existing resources and the newly + * requested resource, an error message will be printed. + * + * Returns 0 on success or a negative error code on failure. + */ +int devm_request_resource(struct device *dev, struct resource *root, + struct resource *new) +{ + struct resource *conflict, **ptr; + + ptr = devres_alloc(devm_resource_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + *ptr = new; + + conflict = request_resource_conflict(root, new); + if (!conflict) { + devres_add(dev, ptr); + return 0; + } + + dev_err(dev, "resource collision: %pR conflicts with %s %pR\n", new, + conflict->name, conflict); + devres_free(ptr); + return -EBUSY; +} +EXPORT_SYMBOL(devm_request_resource); + +static int devm_resource_match(struct device *dev, void *res, void *data) +{ + struct resource **ptr = res; + + if (WARN_ON(!ptr || !*ptr)) + return 0; + + return *ptr == data; +} + +/** + * devm_release_resource() - release a previously requested resource + * @dev: device for which to release the resource + * @new: descriptor of the resource to release + * + * Releases a resource previously requested using devm_request_resource(). + */ +void devm_release_resource(struct device *dev, struct resource *new) +{ + WARN_ON(devres_release(dev, devm_resource_release, devm_resource_match, + new)); +} +EXPORT_SYMBOL(devm_release_resource); + struct region_devres { struct resource *parent; resource_size_t start; |