Merge tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen updates from Konrad Rzeszutek Wilk:
 "which has three neat features:

   - PV multiconsole support, so that there can be hvc1, hvc2, etc; This
     can be used in HVM and in PV mode.

   - P-state and C-state power management driver that uploads said power
     management data to the hypervisor.  It also inhibits cpufreq
     scaling drivers to load so that only the hypervisor can make power
     management decisions - fixing a weird perf bug.

     There is one thing in the Kconfig that you won't like: "default y
     if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)" (note, that it
     all depends on CONFIG_XEN which depends on CONFIG_PARAVIRT which by
     default is off).  I've a fix to convert that boolean expression
     into "default m" which I am going to post after the cpufreq git
     pull - as the two patches to make this work depend on a fix in Dave
     Jones's tree.

   - Function Level Reset (FLR) support in the Xen PCI backend.

  Fixes:

   - Kconfig dependencies for Xen PV keyboard and video
   - Compile warnings and constify fixes
   - Change over to use percpu_xxx instead of this_cpu_xxx"

Fix up trivial conflicts in drivers/tty/hvc/hvc_xen.c due to changes to
a removed commit.

* tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen kconfig: relax INPUT_XEN_KBDDEV_FRONTEND deps
  xen/acpi-processor: C and P-state driver that uploads said data to hypervisor.
  xen: constify all instances of "struct attribute_group"
  xen/xenbus: ignore console/0
  hvc_xen: introduce HVC_XEN_FRONTEND
  hvc_xen: implement multiconsole support
  hvc_xen: support PV on HVM consoles
  xenbus: don't free other end details too early
  xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it.
  xen/setup/pm/acpi: Remove the call to boot_option_idle_override.
  xenbus: address compiler warnings
  xen: use this_cpu_xxx replace percpu_xxx funcs
  xen/pciback: Support pci_reset_function, aka FLR or D3 support.
  pci: Introduce __pci_reset_function_locked to be used when holding device_lock.
  xen: Utilize the restore_msi_irqs hook.

2 files changed, 39 insertions, 3 deletions

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 19834d1c7c36..097e536e8672 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -85,19 +85,34 @@ static struct pcistub_device *pcistub_device_alloc(struct pci_dev *dev)
 static void pcistub_device_release(struct kref *kref)
 {
         struct pcistub_device *psdev;
+        struct xen_pcibk_dev_data *dev_data;
 
         psdev = container_of(kref, struct pcistub_device, kref);
+        dev_data = pci_get_drvdata(psdev->dev);
 
         dev_dbg(&psdev->dev->dev, "pcistub_device_release\n");
 
         xen_unregister_device_domain_owner(psdev->dev);
 
-        /* Clean-up the device */
+        /* Call the reset function which does not take lock as this
+         * is called from "unbind" which takes a device_lock mutex.
+         */
+        __pci_reset_function_locked(psdev->dev);
+        if (pci_load_and_free_saved_state(psdev->dev,
+                                          &dev_data->pci_saved_state)) {
+                dev_dbg(&psdev->dev->dev, "Could not reload PCI state\n");
+        } else
+                pci_restore_state(psdev->dev);
+
+        /* Disable the device */
         xen_pcibk_reset_device(psdev->dev);
+
+        kfree(dev_data);
+        pci_set_drvdata(psdev->dev, NULL);
+
+        /* Clean-up the device */
         xen_pcibk_config_free_dyn_fields(psdev->dev);
         xen_pcibk_config_free_dev(psdev->dev);
-        kfree(pci_get_drvdata(psdev->dev));
-        pci_set_drvdata(psdev->dev, NULL);
 
         psdev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
         pci_dev_put(psdev->dev);
@@ -231,7 +246,17 @@ void pcistub_put_pci_dev(struct pci_dev *dev)
         /* Cleanup our device
          * (so it's ready for the next domain)
          */
+
+        /* This is OK - we are running from workqueue context
+         * and want to inhibit the user from fiddling with 'reset'
+         */
+        pci_reset_function(dev);
+        pci_restore_state(psdev->dev);
+
+        /* This disables the device. */
         xen_pcibk_reset_device(found_psdev->dev);
+
+        /* And cleanup up our emulated fields. */
         xen_pcibk_config_free_dyn_fields(found_psdev->dev);
         xen_pcibk_config_reset_dev(found_psdev->dev);
 
@@ -328,6 +353,16 @@ static int __devinit pcistub_init_device(struct pci_dev *dev)
         if (err)
                 goto config_release;
 
+        dev_dbg(&dev->dev, "reseting (FLR, D3, etc) the device\n");
+        __pci_reset_function_locked(dev);
+
+        /* We need the device active to save the state. */
+        dev_dbg(&dev->dev, "save state of device\n");
+        pci_save_state(dev);
+        dev_data->pci_saved_state = pci_store_saved_state(dev);
+        if (!dev_data->pci_saved_state)
+                dev_err(&dev->dev, "Could not store PCI conf saved state!\n");
+
         /* Now disable the device (this also ensures some private device
          * data is setup before we export)
          */
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index e9b4011c5f9a..a7def010eba3 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -41,6 +41,7 @@ struct xen_pcibk_device {
 
 struct xen_pcibk_dev_data {
         struct list_head config_fields;
+        struct pci_saved_state *pci_saved_state;
         unsigned int permissive:1;
         unsigned int warned_on_write:1;
         unsigned int enable_intx:1;