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, 9 insertions, 0 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 805412cc687..9e3042e7e1c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -167,6 +167,7 @@ struct pci_dev {
         unsigned int    broken_parity_status:1; /* Device generates false positive parity */
         unsigned int    msi_enabled:1;
         unsigned int    msix_enabled:1;
+        unsigned int    is_managed:1;
         atomic_t        enable_cnt;     /* pci_enable_device has been called */
 
         u32             saved_config_space[16]; /* config space saved at suspend time */
@@ -528,6 +529,14 @@ static inline int pci_write_config_dword(struct pci_dev *dev, int where, u32 val
 
 int __must_check pci_enable_device(struct pci_dev *dev);
 int __must_check pci_enable_device_bars(struct pci_dev *dev, int mask);
+int __must_check pcim_enable_device(struct pci_dev *pdev);
+void pcim_pin_device(struct pci_dev *pdev);
+
+static inline int pci_is_managed(struct pci_dev *pdev)
+{
+        return pdev->is_managed;
+}
+
 void pci_disable_device(struct pci_dev *dev);
 void pci_set_master(struct pci_dev *dev);
 #define HAVE_PCI_SET_MWI