Initial import

1 files changed, 270 insertions, 0 deletions

diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c
new file mode 100644
index 000000000..c99f8bb1c
--- /dev/null
+++ b/drivers/xen/xen-pciback/vpci.c
@@ -0,0 +1,270 @@
+/*
+ * PCI Backend - Provides a Virtual PCI bus (with real devices)
+ *               to the frontend
+ *
+ *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/mutex.h>
+#include "pciback.h"
+
+#define PCI_SLOT_MAX 32
+
+struct vpci_dev_data {
+	/* Access to dev_list must be protected by lock */
+	struct list_head dev_list[PCI_SLOT_MAX];
+	struct mutex lock;
+};
+
+static inline struct list_head *list_first(struct list_head *head)
+{
+	return head->next;
+}
+
+static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev,
+					       unsigned int domain,
+					       unsigned int bus,
+					       unsigned int devfn)
+{
+	struct pci_dev_entry *entry;
+	struct pci_dev *dev = NULL;
+	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
+
+	if (domain != 0 || bus != 0)
+		return NULL;
+
+	if (PCI_SLOT(devfn) < PCI_SLOT_MAX) {
+		mutex_lock(&vpci_dev->lock);
+
+		list_for_each_entry(entry,
+				    &vpci_dev->dev_list[PCI_SLOT(devfn)],
+				    list) {
+			if (PCI_FUNC(entry->dev->devfn) == PCI_FUNC(devfn)) {
+				dev = entry->dev;
+				break;
+			}
+		}
+
+		mutex_unlock(&vpci_dev->lock);
+	}
+	return dev;
+}
+
+static inline int match_slot(struct pci_dev *l, struct pci_dev *r)
+{
+	if (pci_domain_nr(l->bus) == pci_domain_nr(r->bus)
+	    && l->bus == r->bus && PCI_SLOT(l->devfn) == PCI_SLOT(r->devfn))
+		return 1;
+
+	return 0;
+}
+
+static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
+				   struct pci_dev *dev, int devid,
+				   publish_pci_dev_cb publish_cb)
+{
+	int err = 0, slot, func = -1;
+	struct pci_dev_entry *t, *dev_entry;
+	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
+
+	if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) {
+		err = -EFAULT;
+		xenbus_dev_fatal(pdev->xdev, err,
+				 "Can't export bridges on the virtual PCI bus");
+		goto out;
+	}
+
+	dev_entry = kmalloc(sizeof(*dev_entry), GFP_KERNEL);
+	if (!dev_entry) {
+		err = -ENOMEM;
+		xenbus_dev_fatal(pdev->xdev, err,
+				 "Error adding entry to virtual PCI bus");
+		goto out;
+	}
+
+	dev_entry->dev = dev;
+
+	mutex_lock(&vpci_dev->lock);
+
+	/*
+	 * Keep multi-function devices together on the virtual PCI bus, except
+	 * virtual functions.
+	 */
+	if (!dev->is_virtfn) {
+		for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+			if (list_empty(&vpci_dev->dev_list[slot]))
+				continue;
+
+			t = list_entry(list_first(&vpci_dev->dev_list[slot]),
+				       struct pci_dev_entry, list);
+
+			if (match_slot(dev, t->dev)) {
+				pr_info("vpci: %s: assign to virtual slot %d func %d\n",
+					pci_name(dev), slot,
+					PCI_FUNC(dev->devfn));
+				list_add_tail(&dev_entry->list,
+					      &vpci_dev->dev_list[slot]);
+				func = PCI_FUNC(dev->devfn);
+				goto unlock;
+			}
+		}
+	}
+
+	/* Assign to a new slot on the virtual PCI bus */
+	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+		if (list_empty(&vpci_dev->dev_list[slot])) {
+			pr_info("vpci: %s: assign to virtual slot %d\n",
+				pci_name(dev), slot);
+			list_add_tail(&dev_entry->list,
+				      &vpci_dev->dev_list[slot]);
+			func = dev->is_virtfn ? 0 : PCI_FUNC(dev->devfn);
+			goto unlock;
+		}
+	}
+
+	err = -ENOMEM;
+	xenbus_dev_fatal(pdev->xdev, err,
+			 "No more space on root virtual PCI bus");
+
+unlock:
+	mutex_unlock(&vpci_dev->lock);
+
+	/* Publish this device. */
+	if (!err)
+		err = publish_cb(pdev, 0, 0, PCI_DEVFN(slot, func), devid);
+	else
+		kfree(dev_entry);
+
+out:
+	return err;
+}
+
+static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
+					struct pci_dev *dev, bool lock)
+{
+	int slot;
+	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
+	struct pci_dev *found_dev = NULL;
+
+	mutex_lock(&vpci_dev->lock);
+
+	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+		struct pci_dev_entry *e;
+
+		list_for_each_entry(e, &vpci_dev->dev_list[slot], list) {
+			if (e->dev == dev) {
+				list_del(&e->list);
+				found_dev = e->dev;
+				kfree(e);
+				goto out;
+			}
+		}
+	}
+
+out:
+	mutex_unlock(&vpci_dev->lock);
+
+	if (found_dev) {
+		if (lock)
+			device_lock(&found_dev->dev);
+		pcistub_put_pci_dev(found_dev);
+		if (lock)
+			device_unlock(&found_dev->dev);
+	}
+}
+
+static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
+{
+	int slot;
+	struct vpci_dev_data *vpci_dev;
+
+	vpci_dev = kmalloc(sizeof(*vpci_dev), GFP_KERNEL);
+	if (!vpci_dev)
+		return -ENOMEM;
+
+	mutex_init(&vpci_dev->lock);
+
+	for (slot = 0; slot < PCI_SLOT_MAX; slot++)
+		INIT_LIST_HEAD(&vpci_dev->dev_list[slot]);
+
+	pdev->pci_dev_data = vpci_dev;
+
+	return 0;
+}
+
+static int __xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
+					 publish_pci_root_cb publish_cb)
+{
+	/* The Virtual PCI bus has only one root */
+	return publish_cb(pdev, 0, 0);
+}
+
+static void __xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
+{
+	int slot;
+	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
+
+	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+		struct pci_dev_entry *e, *tmp;
+		list_for_each_entry_safe(e, tmp, &vpci_dev->dev_list[slot],
+					 list) {
+			struct pci_dev *dev = e->dev;
+			list_del(&e->list);
+			device_lock(&dev->dev);
+			pcistub_put_pci_dev(dev);
+			device_unlock(&dev->dev);
+			kfree(e);
+		}
+	}
+
+	kfree(vpci_dev);
+	pdev->pci_dev_data = NULL;
+}
+
+static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
+					struct xen_pcibk_device *pdev,
+					unsigned int *domain, unsigned int *bus,
+					unsigned int *devfn)
+{
+	struct pci_dev_entry *entry;
+	struct pci_dev *dev = NULL;
+	struct vpci_dev_data *vpci_dev = pdev->pci_dev_data;
+	int found = 0, slot;
+
+	mutex_lock(&vpci_dev->lock);
+	for (slot = 0; slot < PCI_SLOT_MAX; slot++) {
+		list_for_each_entry(entry,
+			    &vpci_dev->dev_list[slot],
+			    list) {
+			dev = entry->dev;
+			if (dev && dev->bus->number == pcidev->bus->number
+				&& pci_domain_nr(dev->bus) ==
+					pci_domain_nr(pcidev->bus)
+				&& dev->devfn == pcidev->devfn) {
+				found = 1;
+				*domain = 0;
+				*bus = 0;
+				*devfn = PCI_DEVFN(slot,
+					 PCI_FUNC(pcidev->devfn));
+			}
+		}
+	}
+	mutex_unlock(&vpci_dev->lock);
+	return found;
+}
+
+const struct xen_pcibk_backend xen_pcibk_vpci_backend = {
+	.name		= "vpci",
+	.init		= __xen_pcibk_init_devices,
+	.free		= __xen_pcibk_release_devices,
+	.find		= __xen_pcibk_get_pcifront_dev,
+	.publish	= __xen_pcibk_publish_pci_roots,
+	.release	= __xen_pcibk_release_pci_dev,
+	.add		= __xen_pcibk_add_pci_dev,
+	.get		= __xen_pcibk_get_pci_dev,
+};