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_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index 28a2a55..8c95c34 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -10,16 +10,19 @@
 #include <linux/sched.h>
 #include "pciback.h"
 
+#define DRV_NAME	"xen-pciback"
 int verbose_request;
 module_param(verbose_request, int, 0644);
 
+static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
+
 /* Ensure a device is has the fake IRQ handler "turned on/off" and is
- * ready to be exported. This MUST be run after pciback_reset_device
+ * ready to be exported. This MUST be run after xen_pcibk_reset_device
  * which does the actual PCI device enable/disable.
  */
-void pciback_control_isr(struct pci_dev *dev, int reset)
+static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
 {
-	struct pciback_dev_data *dev_data;
+	struct xen_pcibk_dev_data *dev_data;
 	int rc;
 	int enable = 0;
 
@@ -66,7 +69,7 @@
 
 	if (enable) {
 		rc = request_irq(dev_data->irq,
-				pciback_guest_interrupt, IRQF_SHARED,
+				xen_pcibk_guest_interrupt, IRQF_SHARED,
 				dev_data->irq_name, dev);
 		if (rc) {
 			dev_err(&dev->dev, "%s: failed to install fake IRQ " \
@@ -92,14 +95,14 @@
 }
 
 /* Ensure a device is "turned off" and ready to be exported.
- * (Also see pciback_config_reset to ensure virtual configuration space is
+ * (Also see xen_pcibk_config_reset to ensure virtual configuration space is
  * ready to be re-exported)
  */
-void pciback_reset_device(struct pci_dev *dev)
+void xen_pcibk_reset_device(struct pci_dev *dev)
 {
 	u16 cmd;
 
-	pciback_control_isr(dev, 1 /* reset device */);
+	xen_pcibk_control_isr(dev, 1 /* reset device */);
 
 	/* Disable devices (but not bridges) */
 	if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
@@ -126,43 +129,176 @@
 		}
 	}
 }
+
+#ifdef CONFIG_PCI_MSI
+static
+int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
+			 struct pci_dev *dev, struct xen_pci_op *op)
+{
+	struct xen_pcibk_dev_data *dev_data;
+	int otherend = pdev->xdev->otherend_id;
+	int status;
+
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
+
+	status = pci_enable_msi(dev);
+
+	if (status) {
+		printk(KERN_ERR "error enable msi for guest %x status %x\n",
+			otherend, status);
+		op->value = 0;
+		return XEN_PCI_ERR_op_failed;
+	}
+
+	/* The value the guest needs is actually the IDT vector, not the
+	 * the local domain's IRQ number. */
+
+	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
+			op->value);
+
+	dev_data = pci_get_drvdata(dev);
+	if (dev_data)
+		dev_data->ack_intr = 0;
+
+	return 0;
+}
+
+static
+int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
+			  struct pci_dev *dev, struct xen_pci_op *op)
+{
+	struct xen_pcibk_dev_data *dev_data;
+
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
+		       pci_name(dev));
+	pci_disable_msi(dev);
+
+	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
+			op->value);
+	dev_data = pci_get_drvdata(dev);
+	if (dev_data)
+		dev_data->ack_intr = 1;
+	return 0;
+}
+
+static
+int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
+			  struct pci_dev *dev, struct xen_pci_op *op)
+{
+	struct xen_pcibk_dev_data *dev_data;
+	int i, result;
+	struct msix_entry *entries;
+
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
+		       pci_name(dev));
+	if (op->value > SH_INFO_MAX_VEC)
+		return -EINVAL;
+
+	entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
+	if (entries == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < op->value; i++) {
+		entries[i].entry = op->msix_entries[i].entry;
+		entries[i].vector = op->msix_entries[i].vector;
+	}
+
+	result = pci_enable_msix(dev, entries, op->value);
+
+	if (result == 0) {
+		for (i = 0; i < op->value; i++) {
+			op->msix_entries[i].entry = entries[i].entry;
+			if (entries[i].vector)
+				op->msix_entries[i].vector =
+					xen_pirq_from_irq(entries[i].vector);
+				if (unlikely(verbose_request))
+					printk(KERN_DEBUG DRV_NAME ": %s: " \
+						"MSI-X[%d]: %d\n",
+						pci_name(dev), i,
+						op->msix_entries[i].vector);
+		}
+	} else {
+		printk(KERN_WARNING DRV_NAME ": %s: failed to enable MSI-X: err %d!\n",
+			pci_name(dev), result);
+	}
+	kfree(entries);
+
+	op->value = result;
+	dev_data = pci_get_drvdata(dev);
+	if (dev_data)
+		dev_data->ack_intr = 0;
+
+	return result;
+}
+
+static
+int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
+			   struct pci_dev *dev, struct xen_pci_op *op)
+{
+	struct xen_pcibk_dev_data *dev_data;
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
+			pci_name(dev));
+	pci_disable_msix(dev);
+
+	/*
+	 * SR-IOV devices (which don't have any legacy IRQ) have
+	 * an undefined IRQ value of zero.
+	 */
+	op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
+	if (unlikely(verbose_request))
+		printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n", pci_name(dev),
+			op->value);
+	dev_data = pci_get_drvdata(dev);
+	if (dev_data)
+		dev_data->ack_intr = 1;
+	return 0;
+}
+#endif
 /*
 * Now the same evtchn is used for both pcifront conf_read_write request
 * as well as pcie aer front end ack. We use a new work_queue to schedule
-* pciback conf_read_write service for avoiding confict with aer_core
+* xen_pcibk conf_read_write service for avoiding confict with aer_core
 * do_recovery job which also use the system default work_queue
 */
-void test_and_schedule_op(struct pciback_device *pdev)
+void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
 {
 	/* Check that frontend is requesting an operation and that we are not
 	 * already processing a request */
 	if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
 	    && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
-		queue_work(pciback_wq, &pdev->op_work);
+		queue_work(xen_pcibk_wq, &pdev->op_work);
 	}
 	/*_XEN_PCIB_active should have been cleared by pcifront. And also make
-	sure pciback is waiting for ack by checking _PCIB_op_pending*/
+	sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
 	if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
 	    && test_bit(_PCIB_op_pending, &pdev->flags)) {
-		wake_up(&aer_wait_queue);
+		wake_up(&xen_pcibk_aer_wait_queue);
 	}
 }
 
 /* Performing the configuration space reads/writes must not be done in atomic
  * context because some of the pci_* functions can sleep (mostly due to ACPI
  * use of semaphores). This function is intended to be called from a work
- * queue in process context taking a struct pciback_device as a parameter */
+ * queue in process context taking a struct xen_pcibk_device as a parameter */
 
-void pciback_do_op(struct work_struct *data)
+void xen_pcibk_do_op(struct work_struct *data)
 {
-	struct pciback_device *pdev =
-		container_of(data, struct pciback_device, op_work);
+	struct xen_pcibk_device *pdev =
+		container_of(data, struct xen_pcibk_device, op_work);
 	struct pci_dev *dev;
-	struct pciback_dev_data *dev_data = NULL;
+	struct xen_pcibk_dev_data *dev_data = NULL;
 	struct xen_pci_op *op = &pdev->sh_info->op;
 	int test_intx = 0;
 
-	dev = pciback_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
+	dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
 
 	if (dev == NULL)
 		op->err = XEN_PCI_ERR_dev_not_found;
@@ -172,25 +308,25 @@
 			test_intx = dev_data->enable_intx;
 		switch (op->cmd) {
 		case XEN_PCI_OP_conf_read:
-			op->err = pciback_config_read(dev,
+			op->err = xen_pcibk_config_read(dev,
 				  op->offset, op->size, &op->value);
 			break;
 		case XEN_PCI_OP_conf_write:
-			op->err = pciback_config_write(dev,
+			op->err = xen_pcibk_config_write(dev,
 				  op->offset, op->size,	op->value);
 			break;
 #ifdef CONFIG_PCI_MSI
 		case XEN_PCI_OP_enable_msi:
-			op->err = pciback_enable_msi(pdev, dev, op);
+			op->err = xen_pcibk_enable_msi(pdev, dev, op);
 			break;
 		case XEN_PCI_OP_disable_msi:
-			op->err = pciback_disable_msi(pdev, dev, op);
+			op->err = xen_pcibk_disable_msi(pdev, dev, op);
 			break;
 		case XEN_PCI_OP_enable_msix:
-			op->err = pciback_enable_msix(pdev, dev, op);
+			op->err = xen_pcibk_enable_msix(pdev, dev, op);
 			break;
 		case XEN_PCI_OP_disable_msix:
-			op->err = pciback_disable_msix(pdev, dev, op);
+			op->err = xen_pcibk_disable_msix(pdev, dev, op);
 			break;
 #endif
 		default:
@@ -201,7 +337,7 @@
 	if (!op->err && dev && dev_data) {
 		/* Transition detected */
 		if ((dev_data->enable_intx != test_intx))
-			pciback_control_isr(dev, 0 /* no reset */);
+			xen_pcibk_control_isr(dev, 0 /* no reset */);
 	}
 	/* Tell the driver domain that we're done. */
 	wmb();
@@ -216,21 +352,21 @@
 	/* Check to see if the driver domain tried to start another request in
 	 * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
 	*/
-	test_and_schedule_op(pdev);
+	xen_pcibk_test_and_schedule_op(pdev);
 }
 
-irqreturn_t pciback_handle_event(int irq, void *dev_id)
+irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
 {
-	struct pciback_device *pdev = dev_id;
+	struct xen_pcibk_device *pdev = dev_id;
 
-	test_and_schedule_op(pdev);
+	xen_pcibk_test_and_schedule_op(pdev);
 
 	return IRQ_HANDLED;
 }
-irqreturn_t pciback_guest_interrupt(int irq, void *dev_id)
+static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
 {
 	struct pci_dev *dev = (struct pci_dev *)dev_id;
-	struct pciback_dev_data *dev_data = pci_get_drvdata(dev);
+	struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
 
 	if (dev_data->isr_on && dev_data->ack_intr) {
 		dev_data->handled++;