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, 17 insertions, 0 deletions

diff --git a/include/linux/io.h b/include/linux/io.h
index 81877ea3930..f5edf9c5de0 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -28,6 +28,23 @@ void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
 int ioremap_page_range(unsigned long addr, unsigned long end,
 		       unsigned long phys_addr, pgprot_t prot);
 
+/*
+ * Managed iomap interface
+ */
+void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
+			       unsigned int nr);
+void devm_ioport_unmap(struct device *dev, void __iomem *addr);
+
+void __iomem * devm_ioremap(struct device *dev, unsigned long offset,
+			    unsigned long size);
+void __iomem * devm_ioremap_nocache(struct device *dev, unsigned long offset,
+				    unsigned long size);
+void devm_iounmap(struct device *dev, void __iomem *addr);
+
+void __iomem * pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);
+void pcim_iounmap(struct pci_dev *pdev, void __iomem *addr);
+void __iomem * const * pcim_iomap_table(struct pci_dev *pdev);
+
 /**
  *	check_signature		-	find BIOS signatures
  *	@io_addr: mmio address to check