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, 6 insertions, 0 deletions

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index e36e86c869fb..5a8ba0b8ccba 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -12,6 +12,7 @@
 #include <linux/sched.h>
 #include <linux/irqflags.h>
 #include <linux/bottom_half.h>
+#include <linux/device.h>
 #include <asm/atomic.h>
 #include <asm/ptrace.h>
 #include <asm/system.h>
@@ -83,6 +84,11 @@ extern int request_irq(unsigned int, irq_handler_t handler,
                        unsigned long, const char *, void *);
 extern void free_irq(unsigned int, void *);
 
+extern int devm_request_irq(struct device *dev, unsigned int irq,
+                            irq_handler_t handler, unsigned long irqflags,
+                            const char *devname, void *dev_id);
+extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
+
 /*
  * On lockdep we dont want to enable hardirqs in hardirq
  * context. Use local_irq_enable_in_hardirq() to annotate