Merge tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
 - Update the Xen ACPI memory and CPU hotplug locking mechanism.
 - Fix PAT issues wherein various applications would not start
 - Fix handling of multiple MSI as AHCI now does it.
 - Fix ARM compile failures.

* tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xenbus: fix compile failure on ARM with Xen enabled
  xen/pci: We don't do multiple MSI's.
  xen/pat: Disable PAT using pat_enabled value.
  xen/acpi: xen cpu hotplug minor updates
  xen/acpi: xen memory hotplug minor updates

3 files changed, 39 insertions, 48 deletions

diff --git a/drivers/xen/xen-acpi-cpuhotplug.c b/drivers/xen/xen-acpi-cpuhotplug.c
index 757827966e34..18c742bec91b 100644
--- a/drivers/xen/xen-acpi-cpuhotplug.c
+++ b/drivers/xen/xen-acpi-cpuhotplug.c
@@ -239,24 +239,6 @@ static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr)
         return AE_OK;
 }
 
-static
-int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
-{
-        acpi_handle phandle;
-        struct acpi_device *pdev;
-
-        if (acpi_get_parent(handle, &phandle))
-                return -ENODEV;
-
-        if (acpi_bus_get_device(phandle, &pdev))
-                return -ENODEV;
-
-        if (acpi_bus_scan(handle))
-                return -ENODEV;
-
-        return 0;
-}
-
 static int acpi_processor_device_remove(struct acpi_device *device)
 {
         pr_debug(PREFIX "Xen does not support CPU hotremove\n");
@@ -272,6 +254,8 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,
         u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
         int result;
 
+        acpi_scan_lock_acquire();
+
         switch (event) {
         case ACPI_NOTIFY_BUS_CHECK:
         case ACPI_NOTIFY_DEVICE_CHECK:
@@ -286,12 +270,16 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,
                 if (!acpi_bus_get_device(handle, &device))
                         break;
 
-                result = acpi_processor_device_add(handle, &device);
+                result = acpi_bus_scan(handle);
                 if (result) {
                         pr_err(PREFIX "Unable to add the device\n");
                         break;
                 }
-
+                result = acpi_bus_get_device(handle, &device);
+                if (result) {
+                        pr_err(PREFIX "Missing device object\n");
+                        break;
+                }
                 ost_code = ACPI_OST_SC_SUCCESS;
                 break;
 
@@ -321,11 +309,13 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,
                                   "Unsupported event [0x%x]\n", event));
 
                 /* non-hotplug event; possibly handled by other handler */
-                return;
+                goto out;
         }
 
         (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
-        return;
+
+out:
+        acpi_scan_lock_release();
 }
 
 static acpi_status is_processor_device(acpi_handle handle)
diff --git a/drivers/xen/xen-acpi-memhotplug.c b/drivers/xen/xen-acpi-memhotplug.c
index 853b12dba5bb..faef5b396051 100644
--- a/drivers/xen/xen-acpi-memhotplug.c
+++ b/drivers/xen/xen-acpi-memhotplug.c
@@ -158,31 +158,17 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
         return 0;
 }
 
-static int
-acpi_memory_get_device(acpi_handle handle,
-                       struct acpi_memory_device **mem_device)
+static int acpi_memory_get_device(acpi_handle handle,
+                                  struct acpi_memory_device **mem_device)
 {
-        acpi_status status;
-        acpi_handle phandle;
         struct acpi_device *device = NULL;
-        struct acpi_device *pdevice = NULL;
-        int result;
+        int result = 0;
 
-        if (!acpi_bus_get_device(handle, &device) && device)
-                goto end;
+        acpi_scan_lock_acquire();
 
-        status = acpi_get_parent(handle, &phandle);
-        if (ACPI_FAILURE(status)) {
-                pr_warn(PREFIX "Cannot find acpi parent\n");
-                return -EINVAL;
-        }
-
-        /* Get the parent device */
-        result = acpi_bus_get_device(phandle, &pdevice);
-        if (result) {
-                pr_warn(PREFIX "Cannot get acpi bus device\n");
-                return -EINVAL;
-        }
+        acpi_bus_get_device(handle, &device);
+        if (device)
+                goto end;
 
         /*
          * Now add the notified device.  This creates the acpi_device
@@ -190,18 +176,28 @@ acpi_memory_get_device(acpi_handle handle,
          */
         result = acpi_bus_scan(handle);
         if (result) {
-                pr_warn(PREFIX "Cannot add acpi bus\n");
-                return -EINVAL;
+                pr_warn(PREFIX "ACPI namespace scan failed\n");
+                result = -EINVAL;
+                goto out;
+        }
+        result = acpi_bus_get_device(handle, &device);
+        if (result) {
+                pr_warn(PREFIX "Missing device object\n");
+                result = -EINVAL;
+                goto out;
         }
 
 end:
         *mem_device = acpi_driver_data(device);
         if (!(*mem_device)) {
-                pr_err(PREFIX "Driver data not found\n");
-                return -ENODEV;
+                pr_err(PREFIX "driver data not found\n");
+                result = -ENODEV;
+                goto out;
         }
 
-        return 0;
+out:
+        acpi_scan_lock_release();
+        return result;
 }
 
 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
@@ -259,12 +255,15 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                         "\nReceived EJECT REQUEST notification for device\n"));
 
+                acpi_scan_lock_acquire();
                 if (acpi_bus_get_device(handle, &device)) {
+                        acpi_scan_lock_release();
                         pr_err(PREFIX "Device doesn't exist\n");
                         break;
                 }
                 mem_device = acpi_driver_data(device);
                 if (!mem_device) {
+                        acpi_scan_lock_release();
                         pr_err(PREFIX "Driver Data is NULL\n");
                         break;
                 }
@@ -274,6 +273,7 @@ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
                  * acpi_bus_remove if Xen support hotremove in the future
                  */
                 acpi_memory_disable_device(mem_device);
+                acpi_scan_lock_release();
                 break;
 
         default:
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index bcf3ba4a6ec1..61786be9138b 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -30,6 +30,7 @@
  * IN THE SOFTWARE.
  */
 
+#include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/spinlock.h>