[Xen-devel] [PATCH 2/6] Allow safe resume for pci FE/BE

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

Make pci FE/BE resumable. 

Signed-off-by Kevin Tian <kevin.tian@xxxxxxxxx>

diff -r eeff197b56e4 -r 7c8c027475f5
linux-2.6-xen-sparse/drivers/xen/pciback/xenbus.c
--- a/linux-2.6-xen-sparse/drivers/xen/pciback/xenbus.c Mon Feb 05
16:57:58 2007 +0800
+++ b/linux-2.6-xen-sparse/drivers/xen/pciback/xenbus.c Mon Feb 05
16:58:10 2007 +0800
@@ -114,8 +114,11 @@ static int pciback_attach(struct pciback
            XenbusStateInitialised)
                goto out;
 
-       /* Wait for frontend to state that it has published the
configuration */
-       if (xenbus_read_driver_state(pdev->xdev->otherend) !=
+       /* Wait for frontend to state that it has published the
+        * configuration. Frontend may be in connected state
+        * immediately after resume.
+        */
+       if (xenbus_read_driver_state(pdev->xdev->otherend) < 
            XenbusStateInitialised)
                goto out;
 
diff -r eeff197b56e4 -r 7c8c027475f5
linux-2.6-xen-sparse/drivers/xen/pcifront/xenbus.c
--- a/linux-2.6-xen-sparse/drivers/xen/pcifront/xenbus.c        Mon Feb
05 16:57:58 2007 +0800
+++ b/linux-2.6-xen-sparse/drivers/xen/pcifront/xenbus.c        Mon Feb
05 16:58:10 2007 +0800
@@ -21,48 +21,59 @@ static struct pcifront_device *alloc_pde
        if (pdev == NULL)
                goto out;
 
+       pdev->sh_info = NULL;
+       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);
+
+       if (pdev->evtchn != INVALID_EVTCHN) {
+               xenbus_free_evtchn(pdev->xdev, pdev->evtchn);
+               pdev->evtchn = INVALID_EVTCHN;
+       }
+
+       if (pdev->gnt_ref != INVALID_GRANT_REF) {
+               gnttab_end_foreign_access(pdev->gnt_ref, 0,
+                                         (unsigned long)pdev->sh_info);
+               pdev->gnt_ref = INVALID_GRANT_REF;
+               pdev->sh_info = NULL;
+       }
+}
+
+static int setup_shring(struct pcifront_device *pdev)
+{
+       int err;
+
        pdev->sh_info =
            (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL);
-       if (pdev->sh_info == NULL) {
-               kfree(pdev);
-               pdev = NULL;
-               goto out;
-       }
+       if (pdev->sh_info == NULL)
+               return -ENOMEM;
+
        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);
+       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);
+      out:
+       return err;
 }
 
 static int pcifront_publish_info(struct pcifront_device *pdev)
@@ -70,14 +81,8 @@ static int pcifront_publish_info(struct 
        int err = 0;
        struct xenbus_transaction trans;
 
-       err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
+       err = setup_shring(pdev);
        if (err < 0)
-               goto out;
-
-       pdev->gnt_ref = err;
-
-       err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
-       if (err)
                goto out;
 
       do_publish:
@@ -263,10 +268,38 @@ static int pcifront_xenbus_probe(struct 
 
 static int pcifront_xenbus_remove(struct xenbus_device *xdev)
 {
-       if (xdev->dev.driver_data)
-               free_pdev(xdev->dev.driver_data);
-
+       struct pcifront_device *pdev = xdev->dev.driver_data;
+
+       if (!pdev)
+               return 0;
+
+       pcifront_free_roots(pdev);
+
+       free_pdev(pdev);
+
+       pdev->xdev->dev.driver_data = NULL;
+
+       kfree(pdev);
        return 0;
+}
+
+static int pcifront_xenbus_resume(struct xenbus_device *dev)
+{
+       struct pcifront_device *pdev = dev->dev.driver_data;
+       int err;
+
+       dev_dbg(&pdev->xdev->dev, "pcifront_xenbus_resume: %s\n",
+               dev->nodename);
+
+       free_pdev(pdev);
+
+       err = pcifront_publish_info(pdev);
+       if (err)
+               goto out;
+
+       err = xenbus_switch_state(pdev->xdev, XenbusStateConnected);
+      out:
+       return err;
 }
 
 static struct xenbus_device_id xenpci_ids[] = {
@@ -280,6 +313,7 @@ static struct xenbus_driver xenbus_pcifr
        .ids                    = xenpci_ids,
        .probe                  = pcifront_xenbus_probe,
        .remove                 = pcifront_xenbus_remove,
+       .resume                 = pcifront_xenbus_resume,
        .otherend_changed       = pcifront_backend_changed,
 };

Attachment: pcifront_resume.patch
Description: pcifront_resume.patch

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