--- /dev/null
+/*
+ * PCI Backend Xenbus Setup - handles setup with frontend and xend
+ *
+ * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/vmalloc.h>
+#include <xen/xenbus.h>
+#include <xen/evtchn.h>
+#include "pciback.h"
+
+#define INVALID_EVTCHN_IRQ (-1)
+
+static struct pciback_device *alloc_pdev(struct xenbus_device *xdev)
+{
+ struct pciback_device *pdev;
+
+ pdev = kzalloc(sizeof(struct pciback_device), GFP_KERNEL);
+ if (pdev == NULL)
+ goto out;
+ dev_dbg(&xdev->dev, "allocated pdev @ 0x%p\n", pdev);
+
+ pdev->xdev = xdev;
+ xdev->dev.driver_data = pdev;
+
+ spin_lock_init(&pdev->dev_lock);
+
+ pdev->sh_area = NULL;
+ pdev->sh_info = NULL;
+ pdev->evtchn_irq = INVALID_EVTCHN_IRQ;
+ pdev->be_watching = 0;
+
+ INIT_WORK(&pdev->op_work, pciback_do_op, pdev);
+
+ if (pciback_init_devices(pdev)) {
+ kfree(pdev);
+ pdev = NULL;
+ }
+ out:
+ return pdev;
+}
+
+static void free_pdev(struct pciback_device *pdev)
+{
+ if (pdev->be_watching)
+ unregister_xenbus_watch(&pdev->be_watch);
+
+ /* Ensure the guest can't trigger our handler before removing devices */
+ if (pdev->evtchn_irq != INVALID_EVTCHN_IRQ)
+ unbind_from_irqhandler(pdev->evtchn_irq, pdev);
+
+ /* If the driver domain started an op, make sure we complete it or
+ * delete it before releasing the shared memory */
+ cancel_delayed_work(&pdev->op_work);
+ flush_scheduled_work();
+
+ if (pdev->sh_info)
+ xenbus_unmap_ring_vfree(pdev->xdev, pdev->sh_area);
+
+ pciback_release_devices(pdev);
+
+ pdev->xdev->dev.driver_data = NULL;
+ pdev->xdev = NULL;
+
+ kfree(pdev);
+}
+
+static int pciback_do_attach(struct pciback_device *pdev, int gnt_ref,
+ int remote_evtchn)
+{
+ int err = 0;
+ int evtchn;
+ struct vm_struct *area;
+
+ dev_dbg(&pdev->xdev->dev,
+ "Attaching to frontend resources - gnt_ref=%d evtchn=%d\n",
+ gnt_ref, remote_evtchn);
+
+ area = xenbus_map_ring_valloc(pdev->xdev, gnt_ref);
+ if (IS_ERR(area)) {
+ err = PTR_ERR(area);
+ goto out;
+ }
+ pdev->sh_area = area;
+ pdev->sh_info = area->addr;
+
+ err = xenbus_bind_evtchn(pdev->xdev, remote_evtchn, &evtchn);
+ if (err)
+ goto out;
+
+ err = bind_evtchn_to_irqhandler(evtchn, pciback_handle_event,
+ SA_SAMPLE_RANDOM, "pciback", pdev);
+ if (err < 0) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error binding event channel to IRQ");
+ goto out;
+ }
+ pdev->evtchn_irq = err;
+ err = 0;
+
+ dev_dbg(&pdev->xdev->dev, "Attached!\n");
+ out:
+ return err;
+}
+
+static int pciback_attach(struct pciback_device *pdev)
+{
+ int err = 0;
+ int gnt_ref, remote_evtchn;
+ char *magic = NULL;
+
+ spin_lock(&pdev->dev_lock);
+
+ /* Make sure we only do this setup once */
+ if (xenbus_read_driver_state(pdev->xdev->nodename) !=
+ XenbusStateInitialised)
+ goto out;
+
+ /* Wait for frontend to state that it has published the configuration */
+ if (xenbus_read_driver_state(pdev->xdev->otherend) !=
+ XenbusStateInitialised)
+ goto out;
+
+ dev_dbg(&pdev->xdev->dev, "Reading frontend config\n");
+
+ err = xenbus_gather(XBT_NIL, pdev->xdev->otherend,
+ "pci-op-ref", "%u", &gnt_ref,
+ "event-channel", "%u", &remote_evtchn,
+ "magic", NULL, &magic, NULL);
+ if (err) {
+ /* If configuration didn't get read correctly, wait longer */
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error reading configuration from frontend");
+ goto out;
+ }
+
+ if (magic == NULL || strcmp(magic, XEN_PCI_MAGIC) != 0) {
+ xenbus_dev_fatal(pdev->xdev, -EFAULT,
+ "version mismatch (%s/%s) with pcifront - "
+ "halting pciback",
+ magic, XEN_PCI_MAGIC);
+ goto out;
+ }
+
+ err = pciback_do_attach(pdev, gnt_ref, remote_evtchn);
+ if (err)
+ goto out;
+
+ dev_dbg(&pdev->xdev->dev, "Connecting...\n");
+
+ err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
+ if (err)
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error switching to connected state!");
+
+ dev_dbg(&pdev->xdev->dev, "Connected? %d\n", err);
+ out:
+ spin_unlock(&pdev->dev_lock);
+
+ if (magic)
+ kfree(magic);
+
+ return err;
+}
+
+static void pciback_frontend_changed(struct xenbus_device *xdev,
+ enum xenbus_state fe_state)
+{
+ struct pciback_device *pdev = xdev->dev.driver_data;
+
+ dev_dbg(&xdev->dev, "fe state changed %d\n", fe_state);
+
+ switch (fe_state) {
+ case XenbusStateInitialised:
+ pciback_attach(pdev);
+ break;
+
+ case XenbusStateClosing:
+ xenbus_switch_state(xdev, XenbusStateClosing);
+ break;
+
+ case XenbusStateClosed:
+ dev_dbg(&xdev->dev, "frontend is gone! unregister device\n");
+ device_unregister(&xdev->dev);
+ break;
+
+ default:
+ break;
+ }
+}
+
+static int pciback_publish_pci_root(struct pciback_device *pdev,
+ unsigned int domain, unsigned int bus)
+{
+ unsigned int d, b;
+ int i, root_num, len, err;
+ char str[64];
+
+ dev_dbg(&pdev->xdev->dev, "Publishing pci roots\n");
+
+ err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename,
+ "root_num", "%d", &root_num);
+ if (err == 0 || err == -ENOENT)
+ root_num = 0;
+ else if (err < 0)
+ goto out;
+
+ /* Verify that we haven't already published this pci root */
+ for (i = 0; i < root_num; 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->nodename,
+ str, "%x:%x", &d, &b);
+ if (err < 0)
+ goto out;
+ if (err != 2) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (d == domain && b == bus) {
+ err = 0;
+ goto out;
+ }
+ }
+
+ len = snprintf(str, sizeof(str), "root-%d", root_num);
+ if (unlikely(len >= (sizeof(str) - 1))) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ dev_dbg(&pdev->xdev->dev, "writing root %d at %04x:%02x\n",
+ root_num, domain, bus);
+
+ err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, str,
+ "%04x:%02x", domain, bus);
+ if (err)
+ goto out;
+
+ err = xenbus_printf(XBT_NIL, pdev->xdev->nodename,
+ "root_num", "%d", (root_num + 1));
+
+ out:
+ return err;
+}
+
+static int pciback_export_device(struct pciback_device *pdev,
+ int domain, int bus, int slot, int func)
+{
+ struct pci_dev *dev;
+ int err = 0;
+
+ dev_dbg(&pdev->xdev->dev, "exporting dom %x bus %x slot %x func %x\n",
+ domain, bus, slot, func);
+
+ dev = pcistub_get_pci_dev_by_slot(pdev, domain, bus, slot, func);
+ if (!dev) {
+ err = -EINVAL;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Couldn't locate PCI device "
+ "(%04x:%02x:%02x.%01x)! "
+ "perhaps already in-use?",
+ domain, bus, slot, func);
+ goto out;
+ }
+
+ err = pciback_add_pci_dev(pdev, dev);
+ if (err)
+ goto out;
+
+ /* TODO: It'd be nice to export a bridge and have all of its children
+ * get exported with it. This may be best done in xend (which will
+ * have to calculate resource usage anyway) but we probably want to
+ * put something in here to ensure that if a bridge gets given to a
+ * driver domain, that all devices under that bridge are not given
+ * to other driver domains (as he who controls the bridge can disable
+ * it and stop the other devices from working).
+ */
+ out:
+ return err;
+}
+
+static int pciback_setup_backend(struct pciback_device *pdev)
+{
+ /* Get configuration from xend (if available now) */
+ int domain, bus, slot, func;
+ int err = 0;
+ int i, num_devs;
+ char dev_str[64];
+
+ spin_lock(&pdev->dev_lock);
+
+ /* It's possible we could get the call to setup twice, so make sure
+ * we're not already connected.
+ */
+ if (xenbus_read_driver_state(pdev->xdev->nodename) !=
+ XenbusStateInitWait)
+ goto out;
+
+ dev_dbg(&pdev->xdev->dev, "getting be setup\n");
+
+ err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d",
+ &num_devs);
+ if (err != 1) {
+ if (err >= 0)
+ err = -EINVAL;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error reading number of devices");
+ goto out;
+ }
+
+ for (i = 0; i < num_devs; i++) {
+ int l = snprintf(dev_str, sizeof(dev_str), "dev-%d", i);
+ if (unlikely(l >= (sizeof(dev_str) - 1))) {
+ err = -ENOMEM;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "String overflow while reading "
+ "configuration");
+ goto out;
+ }
+
+ err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, dev_str,
+ "%x:%x:%x.%x", &domain, &bus, &slot, &func);
+ if (err < 0) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error reading device configuration");
+ goto out;
+ }
+ if (err != 4) {
+ err = -EINVAL;
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error parsing pci device "
+ "configuration");
+ goto out;
+ }
+
+ err = pciback_export_device(pdev, domain, bus, slot, func);
+ if (err)
+ goto out;
+ }
+
+ err = pciback_publish_pci_roots(pdev, pciback_publish_pci_root);
+ if (err) {
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error while publish PCI root buses "
+ "for frontend");
+ goto out;
+ }
+
+ err = xenbus_switch_state(pdev->xdev, XenbusStateInitialised);
+ if (err)
+ xenbus_dev_fatal(pdev->xdev, err,
+ "Error switching to initialised state!");
+
+ out:
+ spin_unlock(&pdev->dev_lock);
+
+ if (!err)
+ /* see if pcifront is already configured (if not, we'll wait) */
+ pciback_attach(pdev);
+
+ return err;
+}
+
+static void pciback_be_watch(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ struct pciback_device *pdev =
+ container_of(watch, struct pciback_device, be_watch);
+
+ switch (xenbus_read_driver_state(pdev->xdev->nodename)) {
+ case XenbusStateInitWait:
+ pciback_setup_backend(pdev);
+ break;
+
+ default:
+ break;
+ }
+}
+
+static int pciback_xenbus_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ int err = 0;
+ struct pciback_device *pdev = alloc_pdev(dev);
+
+ if (pdev == NULL) {
+ err = -ENOMEM;
+ xenbus_dev_fatal(dev, err,
+ "Error allocating pciback_device struct");
+ goto out;
+ }
+
+ /* wait for xend to configure us */
+ err = xenbus_switch_state(dev, XenbusStateInitWait);
+ if (err)
+ goto out;
+
+ /* watch the backend node for backend configuration information */
+ err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch,
+ pciback_be_watch);
+ if (err)
+ goto out;
+ pdev->be_watching = 1;
+
+ /* We need to force a call to our callback here in case
+ * xend already configured us!
+ */
+ pciback_be_watch(&pdev->be_watch, NULL, 0);
+
+ out:
+ return err;
+}
+
+static int pciback_xenbus_remove(struct xenbus_device *dev)
+{
+ struct pciback_device *pdev = dev->dev.driver_data;
+
+ if (pdev != NULL)
+ free_pdev(pdev);
+
+ return 0;
+}
+
+static struct xenbus_device_id xenpci_ids[] = {
+ {"pci"},
+ {{0}},
+};
+
+static struct xenbus_driver xenbus_pciback_driver = {
+ .name = "pciback",
+ .owner = THIS_MODULE,
+ .ids = xenpci_ids,
+ .probe = pciback_xenbus_probe,
+ .remove = pciback_xenbus_remove,
+ .otherend_changed = pciback_frontend_changed,
+};
+
+int __init pciback_xenbus_register(void)
+{
+ if (!is_running_on_xen())
+ return -ENODEV;
+
+ return xenbus_register_backend(&xenbus_pciback_driver);
+}
+
+void __exit pciback_xenbus_unregister(void)
+{
+ xenbus_unregister_driver(&xenbus_pciback_driver);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff