devres: device resource management

Implement device resource management, in short, devres.  A device
driver can allocate arbirary size of devres data which is associated
with a release function.  On driver detach, release function is
invoked on the devres data, then, devres data is freed.

devreses are typed by associated release functions.  Some devreses are
better represented by single instance of the type while others need
multiple instances sharing the same release function.  Both usages are
supported.

devreses can be grouped using devres group such that a device driver
can easily release acquired resources halfway through initialization
or selectively release resources (e.g. resources for port 1 out of 4
ports).

This patch adds devres core including documentation and the following
managed interfaces.

* alloc/free	: devm_kzalloc(), devm_kzfree()
* IO region	: devm_request_region(), devm_release_region()
* IRQ		: devm_request_irq(), devm_free_irq()
* DMA		: dmam_alloc_coherent(), dmam_free_coherent(),
		  dmam_declare_coherent_memory(), dmam_pool_create(),
		  dmam_pool_destroy()
* PCI		: pcim_enable_device(), pcim_pin_device(), pci_is_managed()
* iomap		: devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(),
		  devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(),
		  pcim_iomap(), pcim_iounmap()

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index 5ca1cdba563..26e4692f2d1 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -354,6 +354,41 @@ extern int __must_check device_create_bin_file(struct device *dev,
                                                struct bin_attribute *attr);
 extern void device_remove_bin_file(struct device *dev,
                                    struct bin_attribute *attr);
+
+/* device resource management */
+typedef void (*dr_release_t)(struct device *dev, void *res);
+typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);
+
+#ifdef CONFIG_DEBUG_DEVRES
+extern void * __devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
+                             const char *name);
+#define devres_alloc(release, size, gfp) \
+        __devres_alloc(release, size, gfp, #release)
+#else
+extern void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp);
+#endif
+extern void devres_free(void *res);
+extern void devres_add(struct device *dev, void *res);
+extern void * devres_find(struct device *dev, dr_release_t release,
+                          dr_match_t match, void *match_data);
+extern void * devres_get(struct device *dev, void *new_res,
+                         dr_match_t match, void *match_data);
+extern void * devres_remove(struct device *dev, dr_release_t release,
+                            dr_match_t match, void *match_data);
+extern int devres_destroy(struct device *dev, dr_release_t release,
+                          dr_match_t match, void *match_data);
+
+/* devres group */
+extern void * __must_check devres_open_group(struct device *dev, void *id,
+                                             gfp_t gfp);
+extern void devres_close_group(struct device *dev, void *id);
+extern void devres_remove_group(struct device *dev, void *id);
+extern int devres_release_group(struct device *dev, void *id);
+
+/* managed kzalloc/kfree for device drivers, no kmalloc, always use kzalloc */
+extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
+extern void devm_kfree(struct device *dev, void *p);
+
 struct device {
         struct klist            klist_children;
         struct klist_node       knode_parent;           /* node in sibling list */
@@ -397,6 +432,9 @@ struct device {
         /* arch specific additions */
         struct dev_archdata     archdata;
 
+        spinlock_t              devres_lock;
+        struct list_head        devres_head;
+
         /* class_device migration path */
         struct list_head        node;
         struct class            *class;