--- /dev/null
+/*
+ * PCI Frontend Xenbus Setup - handles setup with backend (imports page/evtchn)
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <xen/xenbus.h>
+#include <xen/gnttab.h>
+#include "pcifront.h"
+
+#define INVALID_GRANT_REF (0)
+#define INVALID_EVTCHN (-1)
+
+static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev)
+{
+ struct pcifront_device *pdev;
+
+ pdev = kmalloc(sizeof(struct pcifront_device), GFP_KERNEL);
+ if (pdev == NULL)
+ goto out;
+
+ pdev->sh_info =
+ (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
+ if (pdev->sh_info == NULL) {
+ kfree(pdev);
+ pdev = NULL;
+ goto out;
+ }
+ pdev->sh_info->flags = 0;
+
+ xdev->dev.driver_data = pdev;
+ pdev->xdev = xdev;
+
+ INIT_LIST_HEAD(&pdev->root_buses);
+
+ spin_lock_init(&pdev->dev_lock);
+ spin_lock_init(&pdev->sh_info_lock);
+
+ pdev->evtchn = INVALID_EVTCHN;
+ pdev->gnt_ref = INVALID_GRANT_REF;
+
+ dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n",
+ pdev, pdev->sh_info);
+ out:
+ return pdev;
+}
+
+static void free_pdev(struct pcifront_device *pdev)
+{
+ dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev);
+
+ pcifront_free_roots(pdev);
+
+ if (pdev->evtchn != INVALID_EVTCHN)
+ xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
+
+ if (pdev->gnt_ref != INVALID_GRANT_REF)
+ gnttab_end_foreign_access(pdev->gnt_ref, 0,
+ (unsigned long)pdev->sh_info);
+
+ pdev->xdev->dev.driver_data = NULL;
+
+ kfree(pdev);
+}
+
+static int pcifront_publish_info(struct pcifront_device *pdev)
+{
+ int err = 0;
+ struct xenbus_transaction trans;
+
+ err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
+ if (err < 0)
+ goto out;
+
+ pdev->gnt_ref = err;
+
+ err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
+ if (err)
+ goto out;
+
+ do_publish:
+ err = xenbus_transaction_start(&trans);
+ if (err) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error writing configuration for backend "
+ "(start transaction)");
+ goto out;
+ }
+
+ err = xenbus_printf(trans, pdev->xdev->nodename,
+ "pci-op-ref", "%u", pdev->gnt_ref);
+ if (!err)
+ err = xenbus_printf(trans, pdev->xdev->nodename,
+ "event-channel", "%u", pdev->evtchn);
+ if (!err)
+ err = xenbus_printf(trans, pdev->xdev->nodename,
+ "magic", XEN_PCI_MAGIC);
+
+ if (err) {
+ xenbus_transaction_end(trans, 1);
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error writing configuration for backend");
+ goto out;
+ } else {
+ err = xenbus_transaction_end(trans, 0);
+ if (err == -EAGAIN)
+ goto do_publish;
+ else if (err) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error completing transaction "
+ "for backend");
+ goto out;
+ }
+ }
+
+ xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
+
+ dev_dbg(&pdev->xdev->dev, "publishing successful!\n");
+
+ out:
+ return err;
+}
+
+static int pcifront_try_connect(struct pcifront_device *pdev)
+{
+ int err = -EFAULT;
+ int i, num_roots, len;
+ char str[64];
+ unsigned int domain, bus;
+
+ spin_lock(&pdev->dev_lock);
+
+ /* Only connect once */
+ if (xenbus_read_driver_state(pdev->xdev->nodename) !=
+ XenbusStateInitialised)
+ goto out;
+
+ err = pcifront_connect(pdev);
+ if (err) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error connecting PCI Frontend");
+ goto out;
+ }
+
+ err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend,
+ "root_num", "%d", &num_roots);
+ if (err == -ENOENT) {
+ xenbus_dev_error(pdev->xdev, err,
+ "No PCI Roots found, trying 0000:00");
+ err = pcifront_scan_root(pdev, 0, 0);
+ num_roots = 0;
+ } else if (err != 1) {
+ if (err == 0)
+ err = -EINVAL;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error reading number of PCI roots");
+ goto out;
+ }
+
+ for (i = 0; i < num_roots; i++) {
+ len = snprintf(str, sizeof(str), "root-%d", i);
+ if (unlikely(len >= (sizeof(str) - 1))) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str,
+ "%x:%x", &domain, &bus);
+ if (err != 2) {
+ if (err >= 0)
+ err = -EINVAL;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error reading PCI root %d", i);
+ goto out;
+ }
+
+ err = pcifront_scan_root(pdev, domain, bus);
+ if (err) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error scanning PCI root %04x:%02x",
+ domain, bus);
+ goto out;
+ }
+ }
+
+ err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
+ if (err)
+ goto out;
+
+ out:
+ spin_unlock(&pdev->dev_lock);
+ return err;
+}
+
+static int pcifront_try_disconnect(struct pcifront_device *pdev)
+{
+ int err = 0;
+ enum xenbus_state prev_state;
+
+ spin_lock(&pdev->dev_lock);
+
+ prev_state = xenbus_read_driver_state(pdev->xdev->nodename);
+
+ if (prev_state < XenbusStateClosing)
+ err = xenbus_switch_state(pdev->xdev, XenbusStateClosing);
+
+ if (!err && prev_state == XenbusStateConnected)
+ pcifront_disconnect(pdev);
+
+ spin_unlock(&pdev->dev_lock);
+
+ return err;
+}
+
+static void pcifront_backend_changed(struct xenbus_device *xdev,
+ enum xenbus_state be_state)
+{
+ struct pcifront_device *pdev = xdev->dev.driver_data;
+
+ switch (be_state) {
+ case XenbusStateClosing:
+ dev_warn(&xdev->dev, "backend going away!\n");
+ pcifront_try_disconnect(pdev);
+ break;
+
+ case XenbusStateClosed:
+ dev_warn(&xdev->dev, "backend went away!\n");
+ pcifront_try_disconnect(pdev);
+
+ device_unregister(&pdev->xdev->dev);
+ break;
+
+ case XenbusStateConnected:
+ pcifront_try_connect(pdev);
+ break;
+
+ default:
+ break;
+ }
+}
+
+static int pcifront_xenbus_probe(struct xenbus_device *xdev,
+ const struct xenbus_device_id *id)
+{
+ int err = 0;
+ struct pcifront_device *pdev = alloc_pdev(xdev);
+
+ if (pdev == NULL) {
+ err = -ENOMEM;
+ xenbus_dev_fatal(xdev, err,
+ "Error allocating pcifront_device struct");
+ goto out;
+ }
+
+ err = pcifront_publish_info(pdev);
+
+ out:
+ return err;
+}
+
+static int pcifront_xenbus_remove(struct xenbus_device *xdev)
+{
+ if (xdev->dev.driver_data)
+ free_pdev(xdev->dev.driver_data);
+
+ return 0;
+}
+
+static struct xenbus_device_id xenpci_ids[] = {
+ {"pci"},
+ {{0}},
+};
+
+static struct xenbus_driver xenbus_pcifront_driver = {
+ .name = "pcifront",
+ .owner = THIS_MODULE,
+ .ids = xenpci_ids,
+ .probe = pcifront_xenbus_probe,
+ .remove = pcifront_xenbus_remove,
+ .otherend_changed = pcifront_backend_changed,
+};
+
+static int __init pcifront_init(void)
+{
+ if (!is_running_on_xen())
+ return -ENODEV;
+
+ return xenbus_register_frontend(&xenbus_pcifront_driver);
+}
+
+/* Initialize after the Xen PCI Frontend Stub is initialized */
+subsys_initcall(pcifront_init);
git://git.onelab.eu / linux-2.6.git / blobdiff