xen/pciback: Drop two backends, squash and cleanup some code.

 - Remove the slot and controller controller backend as they
   are not used.
 - Document the find pciback_[read|write]_config_[byte|word|dword]
   to make it easier to find.
 - Collapse the code from conf_space_capability_msi into pciback_ops.c
 - Collapse conf_space_capability_[pm|vpd].c in conf_space_capability.c
   [and remove the conf_space_capability.h file]
 - Rename all visible functions from pciback to xen_pcibk.
 - Rename all the printk/pr_info, etc that use the "pciback" to say
   "xen-pciback".
 - Convert functions that are not referenced outside the code to be
   static to save on name space.
 - Do the same thing for structures that are internal to the driver.
 - Run checkpatch.pl after the renames and fixup its warnings and
   fix any compile errors caused by the variable rename
 - Cleanup any structs that checkpath.pl commented about or just
   look odd.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index 5c14020..427b7fd 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -25,25 +25,19 @@
 #define _PCIB_op_pending	(1)
 #define PCIB_op_pending		(1<<(_PCIB_op_pending))
 
-struct pciback_device {
+struct xen_pcibk_device {
 	void *pci_dev_data;
 	spinlock_t dev_lock;
-
 	struct xenbus_device *xdev;
-
 	struct xenbus_watch be_watch;
 	u8 be_watching;
-
 	int evtchn_irq;
-
 	struct xen_pci_sharedinfo *sh_info;
-
 	unsigned long flags;
-
 	struct work_struct op_work;
 };
 
-struct pciback_dev_data {
+struct xen_pcibk_dev_data {
 	struct list_head config_fields;
 	unsigned int permissive:1;
 	unsigned int warned_on_write:1;
@@ -52,91 +46,78 @@
 	unsigned int ack_intr:1; /* .. and ACK-ing */
 	unsigned long handled;
 	unsigned int irq; /* Saved in case device transitions to MSI/MSI-X */
-	char irq_name[0]; /* pciback[000:04:00.0] */
+	char irq_name[0]; /* xen-pcibk[000:04:00.0] */
 };
 
-/* Used by XenBus and pciback_ops.c */
-extern wait_queue_head_t aer_wait_queue;
-extern struct workqueue_struct *pciback_wq;
+/* Used by XenBus and xen_pcibk_ops.c */
+extern wait_queue_head_t xen_pcibk_aer_wait_queue;
+extern struct workqueue_struct *xen_pcibk_wq;
 /* Used by pcistub.c and conf_space_quirks.c */
-extern struct list_head pciback_quirks;
+extern struct list_head xen_pcibk_quirks;
 
 /* Get/Put PCI Devices that are hidden from the PCI Backend Domain */
-struct pci_dev *pcistub_get_pci_dev_by_slot(struct pciback_device *pdev,
+struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
 					    int domain, int bus,
 					    int slot, int func);
-struct pci_dev *pcistub_get_pci_dev(struct pciback_device *pdev,
+struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
 				    struct pci_dev *dev);
 void pcistub_put_pci_dev(struct pci_dev *dev);
 
 /* Ensure a device is turned off or reset */
-void pciback_reset_device(struct pci_dev *pdev);
+void xen_pcibk_reset_device(struct pci_dev *pdev);
 
 /* Access a virtual configuration space for a PCI device */
-int pciback_config_init(void);
-int pciback_config_init_dev(struct pci_dev *dev);
-void pciback_config_free_dyn_fields(struct pci_dev *dev);
-void pciback_config_reset_dev(struct pci_dev *dev);
-void pciback_config_free_dev(struct pci_dev *dev);
-int pciback_config_read(struct pci_dev *dev, int offset, int size,
-			u32 *ret_val);
-int pciback_config_write(struct pci_dev *dev, int offset, int size, u32 value);
+int xen_pcibk_config_init(void);
+int xen_pcibk_config_init_dev(struct pci_dev *dev);
+void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev);
+void xen_pcibk_config_reset_dev(struct pci_dev *dev);
+void xen_pcibk_config_free_dev(struct pci_dev *dev);
+int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
+			  u32 *ret_val);
+int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size,
+			   u32 value);
 
 /* Handle requests for specific devices from the frontend */
-typedef int (*publish_pci_dev_cb) (struct pciback_device *pdev,
+typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev,
 				   unsigned int domain, unsigned int bus,
 				   unsigned int devfn, unsigned int devid);
-typedef int (*publish_pci_root_cb) (struct pciback_device *pdev,
+typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev,
 				    unsigned int domain, unsigned int bus);
-int pciback_add_pci_dev(struct pciback_device *pdev, struct pci_dev *dev,
-			int devid, publish_pci_dev_cb publish_cb);
-void pciback_release_pci_dev(struct pciback_device *pdev, struct pci_dev *dev);
-struct pci_dev *pciback_get_pci_dev(struct pciback_device *pdev,
-				    unsigned int domain, unsigned int bus,
-				    unsigned int devfn);
+int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev *dev,
+			  int devid, publish_pci_dev_cb publish_cb);
+void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
+			       struct pci_dev *dev);
+struct pci_dev *xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
+				      unsigned int domain, unsigned int bus,
+				      unsigned int devfn);
 
 /**
-* Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in pciback
+* Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk
 * before sending aer request to pcifront, so that guest could identify
-* device, coopearte with pciback to finish aer recovery job if device driver
+* device, coopearte with xen_pcibk to finish aer recovery job if device driver
 * has the capability
 */
 
-int pciback_get_pcifront_dev(struct pci_dev *pcidev,
-			     struct pciback_device *pdev,
-			     unsigned int *domain, unsigned int *bus,
-			     unsigned int *devfn);
-int pciback_init_devices(struct pciback_device *pdev);
-int pciback_publish_pci_roots(struct pciback_device *pdev,
-			      publish_pci_root_cb cb);
-void pciback_release_devices(struct pciback_device *pdev);
+int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
+			       struct xen_pcibk_device *pdev,
+			       unsigned int *domain, unsigned int *bus,
+			       unsigned int *devfn);
+int xen_pcibk_init_devices(struct xen_pcibk_device *pdev);
+int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
+				publish_pci_root_cb cb);
+void xen_pcibk_release_devices(struct xen_pcibk_device *pdev);
 
 /* Handles events from front-end */
-irqreturn_t pciback_handle_event(int irq, void *dev_id);
-void pciback_do_op(struct work_struct *data);
+irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
+void xen_pcibk_do_op(struct work_struct *data);
 
-int pciback_xenbus_register(void);
-void pciback_xenbus_unregister(void);
+int xen_pcibk_xenbus_register(void);
+void xen_pcibk_xenbus_unregister(void);
 
-#ifdef CONFIG_PCI_MSI
-int pciback_enable_msi(struct pciback_device *pdev,
-			struct pci_dev *dev, struct xen_pci_op *op);
-
-int pciback_disable_msi(struct pciback_device *pdev,
-			struct pci_dev *dev, struct xen_pci_op *op);
-
-
-int pciback_enable_msix(struct pciback_device *pdev,
-			struct pci_dev *dev, struct xen_pci_op *op);
-
-int pciback_disable_msix(struct pciback_device *pdev,
-			struct pci_dev *dev, struct xen_pci_op *op);
-#endif
 extern int verbose_request;
 
-void test_and_schedule_op(struct pciback_device *pdev);
+void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev);
 #endif
 
 /* Handles shared IRQs that can to device domain and control domain. */
-void pciback_irq_handler(struct pci_dev *dev, int reset);
-irqreturn_t pciback_guest_interrupt(int irq, void *dev_id);
+void xen_pcibk_irq_handler(struct pci_dev *dev, int reset);