]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
Merge remote-tracking branch 'xen-two/linux-next'
authorStephen Rothwell <sfr@canb.auug.org.au>
Wed, 20 Feb 2013 04:02:20 +0000 (15:02 +1100)
committerStephen Rothwell <sfr@canb.auug.org.au>
Wed, 20 Feb 2013 04:02:26 +0000 (15:02 +1100)
1  2 
arch/x86/xen/enlighten.c
arch/x86/xen/mmu.c
arch/x86/xen/setup.c
drivers/net/xen-netback/netback.c
drivers/xen/events.c
drivers/xen/xen-acpi-cpuhotplug.c
drivers/xen/xen-acpi-memhotplug.c

Simple merge
index f5e86eee4e0ec9c7b80c94433f4ace0be0fe7403,62a6f637b53cf1544925c2891ab836f5146ba303..aabe2c15f5b23581b9a5eb957aa86fee8efecf5e
@@@ -2171,6 -2218,12 +2191,11 @@@ static const struct pv_mmu_ops xen_mmu_
  void __init xen_init_mmu_ops(void)
  {
        x86_init.paging.pagetable_init = xen_pagetable_init;
 -      x86_init.mapping.pagetable_reserve = xen_mapping_pagetable_reserve;
+       if (xen_feature(XENFEAT_auto_translated_physmap)) {
+               pv_mmu_ops.flush_tlb_others = xen_flush_tlb_others;
+               return;
+       }
        pv_mmu_ops = xen_mmu_ops;
  
        memset(dummy_mapping, 0xff, PAGE_SIZE);
Simple merge
Simple merge
Simple merge
index 0000000000000000000000000000000000000000,9eefbb0f79a3ab6f49403334b7ebfea6279026b1..757827966e3407facfac7c912ec762f292e0e385
mode 000000,100644..100644
--- /dev/null
@@@ -1,0 -1,471 +1,471 @@@
 -static int xen_acpi_processor_remove(struct acpi_device *device, int type)
+ /*
+  * Copyright (C) 2012 Intel Corporation
+  *    Author: Liu Jinsong <jinsong.liu@intel.com>
+  *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or (at
+  * your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful, but
+  * WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+  * NON INFRINGEMENT.  See the GNU General Public License for more
+  * details.
+  */
+ #include <linux/kernel.h>
+ #include <linux/module.h>
+ #include <linux/init.h>
+ #include <linux/types.h>
+ #include <linux/cpu.h>
+ #include <linux/acpi.h>
+ #include <linux/uaccess.h>
+ #include <acpi/acpi_bus.h>
+ #include <acpi/acpi_drivers.h>
+ #include <acpi/processor.h>
+ #include <xen/acpi.h>
+ #include <xen/interface/platform.h>
+ #include <asm/xen/hypercall.h>
+ #define PREFIX "ACPI:xen_cpu_hotplug:"
+ #define INSTALL_NOTIFY_HANDLER                0
+ #define UNINSTALL_NOTIFY_HANDLER      1
+ static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr);
+ /* --------------------------------------------------------------------------
+                               Driver Interface
+ -------------------------------------------------------------------------- */
+ static int xen_acpi_processor_enable(struct acpi_device *device)
+ {
+       acpi_status status = 0;
+       unsigned long long value;
+       union acpi_object object = { 0 };
+       struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+       struct acpi_processor *pr;
+       pr = acpi_driver_data(device);
+       if (!pr) {
+               pr_err(PREFIX "Cannot find driver data\n");
+               return -EINVAL;
+       }
+       if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
+               /* Declared with "Processor" statement; match ProcessorID */
+               status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
+               if (ACPI_FAILURE(status)) {
+                       pr_err(PREFIX "Evaluating processor object\n");
+                       return -ENODEV;
+               }
+               pr->acpi_id = object.processor.proc_id;
+       } else {
+               /* Declared with "Device" statement; match _UID */
+               status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
+                                               NULL, &value);
+               if (ACPI_FAILURE(status)) {
+                       pr_err(PREFIX "Evaluating processor _UID\n");
+                       return -ENODEV;
+               }
+               pr->acpi_id = value;
+       }
+       pr->id = xen_pcpu_id(pr->acpi_id);
+       if ((int)pr->id < 0)
+               /* This cpu is not presented at hypervisor, try to hotadd it */
+               if (ACPI_FAILURE(xen_acpi_cpu_hotadd(pr))) {
+                       pr_err(PREFIX "Hotadd CPU (acpi_id = %d) failed.\n",
+                                       pr->acpi_id);
+                       return -ENODEV;
+               }
+       return 0;
+ }
+ static int __cpuinit xen_acpi_processor_add(struct acpi_device *device)
+ {
+       int ret;
+       struct acpi_processor *pr;
+       if (!device)
+               return -EINVAL;
+       pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
+       if (!pr)
+               return -ENOMEM;
+       pr->handle = device->handle;
+       strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
+       strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
+       device->driver_data = pr;
+       ret = xen_acpi_processor_enable(device);
+       if (ret)
+               pr_err(PREFIX "Error when enabling Xen processor\n");
+       return ret;
+ }
 -      if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR))
++static int xen_acpi_processor_remove(struct acpi_device *device)
+ {
+       struct acpi_processor *pr;
+       if (!device)
+               return -EINVAL;
+       pr = acpi_driver_data(device);
+       if (!pr)
+               return -EINVAL;
+       kfree(pr);
+       return 0;
+ }
+ /*--------------------------------------------------------------
+               Acpi processor hotplug support
+ --------------------------------------------------------------*/
+ static int is_processor_present(acpi_handle handle)
+ {
+       acpi_status status;
+       unsigned long long sta = 0;
+       status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+       if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
+               return 1;
+       /*
+        * _STA is mandatory for a processor that supports hot plug
+        */
+       if (status == AE_NOT_FOUND)
+               pr_info(PREFIX "Processor does not support hot plug\n");
+       else
+               pr_info(PREFIX "Processor Device is not present");
+       return 0;
+ }
+ static int xen_apic_id(acpi_handle handle)
+ {
+       struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+       union acpi_object *obj;
+       struct acpi_madt_local_apic *lapic;
+       int apic_id;
+       if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
+               return -EINVAL;
+       if (!buffer.length || !buffer.pointer)
+               return -EINVAL;
+       obj = buffer.pointer;
+       if (obj->type != ACPI_TYPE_BUFFER ||
+           obj->buffer.length < sizeof(*lapic)) {
+               kfree(buffer.pointer);
+               return -EINVAL;
+       }
+       lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
+       if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
+           !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
+               kfree(buffer.pointer);
+               return -EINVAL;
+       }
+       apic_id = (uint32_t)lapic->id;
+       kfree(buffer.pointer);
+       buffer.length = ACPI_ALLOCATE_BUFFER;
+       buffer.pointer = NULL;
+       return apic_id;
+ }
+ static int xen_hotadd_cpu(struct acpi_processor *pr)
+ {
+       int cpu_id, apic_id, pxm;
+       struct xen_platform_op op;
+       apic_id = xen_apic_id(pr->handle);
+       if (apic_id < 0) {
+               pr_err(PREFIX "Failed to get apic_id for acpi_id %d\n",
+                               pr->acpi_id);
+               return -ENODEV;
+       }
+       pxm = xen_acpi_get_pxm(pr->handle);
+       if (pxm < 0) {
+               pr_err(PREFIX "Failed to get _PXM for acpi_id %d\n",
+                               pr->acpi_id);
+               return pxm;
+       }
+       op.cmd = XENPF_cpu_hotadd;
+       op.u.cpu_add.apic_id = apic_id;
+       op.u.cpu_add.acpi_id = pr->acpi_id;
+       op.u.cpu_add.pxm = pxm;
+       cpu_id = HYPERVISOR_dom0_op(&op);
+       if (cpu_id < 0)
+               pr_err(PREFIX "Failed to hotadd CPU for acpi_id %d\n",
+                               pr->acpi_id);
+       return cpu_id;
+ }
+ static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr)
+ {
+       if (!is_processor_present(pr->handle))
+               return AE_ERROR;
+       pr->id = xen_hotadd_cpu(pr);
+       if ((int)pr->id < 0)
+               return AE_ERROR;
+       /*
+        * Sync with Xen hypervisor, providing new /sys/.../xen_cpuX
+        * interface after cpu hotadded.
+        */
+       xen_pcpu_hotplug_sync();
+       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");
+       return -ENOSYS;
+ }
+ static void acpi_processor_hotplug_notify(acpi_handle handle,
+                                         u32 event, void *data)
+ {
+       struct acpi_processor *pr;
+       struct acpi_device *device = NULL;
+       u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
+       int result;
+       switch (event) {
+       case ACPI_NOTIFY_BUS_CHECK:
+       case ACPI_NOTIFY_DEVICE_CHECK:
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                       "Processor driver received %s event\n",
+                       (event == ACPI_NOTIFY_BUS_CHECK) ?
+                       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
+               if (!is_processor_present(handle))
+                       break;
+               if (!acpi_bus_get_device(handle, &device))
+                       break;
+               result = acpi_processor_device_add(handle, &device);
+               if (result) {
+                       pr_err(PREFIX "Unable to add the device\n");
+                       break;
+               }
+               ost_code = ACPI_OST_SC_SUCCESS;
+               break;
+       case ACPI_NOTIFY_EJECT_REQUEST:
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                 "received ACPI_NOTIFY_EJECT_REQUEST\n"));
+               if (acpi_bus_get_device(handle, &device)) {
+                       pr_err(PREFIX "Device don't exist, dropping EJECT\n");
+                       break;
+               }
+               pr = acpi_driver_data(device);
+               if (!pr) {
+                       pr_err(PREFIX "Driver data is NULL, dropping EJECT\n");
+                       break;
+               }
+               /*
+                * TBD: implement acpi_processor_device_remove if Xen support
+                * CPU hotremove in the future.
+                */
+               acpi_processor_device_remove(device);
+               break;
+       default:
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                 "Unsupported event [0x%x]\n", event));
+               /* non-hotplug event; possibly handled by other handler */
+               return;
+       }
+       (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
+       return;
+ }
+ static acpi_status is_processor_device(acpi_handle handle)
+ {
+       struct acpi_device_info *info;
+       char *hid;
+       acpi_status status;
+       status = acpi_get_object_info(handle, &info);
+       if (ACPI_FAILURE(status))
+               return status;
+       if (info->type == ACPI_TYPE_PROCESSOR) {
+               kfree(info);
+               return AE_OK;   /* found a processor object */
+       }
+       if (!(info->valid & ACPI_VALID_HID)) {
+               kfree(info);
+               return AE_ERROR;
+       }
+       hid = info->hardware_id.string;
+       if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
+               kfree(info);
+               return AE_ERROR;
+       }
+       kfree(info);
+       return AE_OK;   /* found a processor device object */
+ }
+ static acpi_status
+ processor_walk_namespace_cb(acpi_handle handle,
+                           u32 lvl, void *context, void **rv)
+ {
+       acpi_status status;
+       int *action = context;
+       status = is_processor_device(handle);
+       if (ACPI_FAILURE(status))
+               return AE_OK;   /* not a processor; continue to walk */
+       switch (*action) {
+       case INSTALL_NOTIFY_HANDLER:
+               acpi_install_notify_handler(handle,
+                                           ACPI_SYSTEM_NOTIFY,
+                                           acpi_processor_hotplug_notify,
+                                           NULL);
+               break;
+       case UNINSTALL_NOTIFY_HANDLER:
+               acpi_remove_notify_handler(handle,
+                                          ACPI_SYSTEM_NOTIFY,
+                                          acpi_processor_hotplug_notify);
+               break;
+       default:
+               break;
+       }
+       /* found a processor; skip walking underneath */
+       return AE_CTRL_DEPTH;
+ }
+ static
+ void acpi_processor_install_hotplug_notify(void)
+ {
+       int action = INSTALL_NOTIFY_HANDLER;
+       acpi_walk_namespace(ACPI_TYPE_ANY,
+                           ACPI_ROOT_OBJECT,
+                           ACPI_UINT32_MAX,
+                           processor_walk_namespace_cb, NULL, &action, NULL);
+ }
+ static
+ void acpi_processor_uninstall_hotplug_notify(void)
+ {
+       int action = UNINSTALL_NOTIFY_HANDLER;
+       acpi_walk_namespace(ACPI_TYPE_ANY,
+                           ACPI_ROOT_OBJECT,
+                           ACPI_UINT32_MAX,
+                           processor_walk_namespace_cb, NULL, &action, NULL);
+ }
+ static const struct acpi_device_id processor_device_ids[] = {
+       {ACPI_PROCESSOR_OBJECT_HID, 0},
+       {ACPI_PROCESSOR_DEVICE_HID, 0},
+       {"", 0},
+ };
+ MODULE_DEVICE_TABLE(acpi, processor_device_ids);
+ static struct acpi_driver xen_acpi_processor_driver = {
+       .name = "processor",
+       .class = ACPI_PROCESSOR_CLASS,
+       .ids = processor_device_ids,
+       .ops = {
+               .add = xen_acpi_processor_add,
+               .remove = xen_acpi_processor_remove,
+               },
+ };
+ static int __init xen_acpi_processor_init(void)
+ {
+       int result = 0;
+       if (!xen_initial_domain())
+               return -ENODEV;
+       /* unregister the stub which only used to reserve driver space */
+       xen_stub_processor_exit();
+       result = acpi_bus_register_driver(&xen_acpi_processor_driver);
+       if (result < 0) {
+               xen_stub_processor_init();
+               return result;
+       }
+       acpi_processor_install_hotplug_notify();
+       return 0;
+ }
+ static void __exit xen_acpi_processor_exit(void)
+ {
+       if (!xen_initial_domain())
+               return;
+       acpi_processor_uninstall_hotplug_notify();
+       acpi_bus_unregister_driver(&xen_acpi_processor_driver);
+       /*
+        * stub reserve space again to prevent any chance of native
+        * driver loading.
+        */
+       xen_stub_processor_init();
+       return;
+ }
+ module_init(xen_acpi_processor_init);
+ module_exit(xen_acpi_processor_exit);
+ ACPI_MODULE_NAME("xen-acpi-cpuhotplug");
+ MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
+ MODULE_DESCRIPTION("Xen Hotplug CPU Driver");
+ MODULE_LICENSE("GPL");
index 0000000000000000000000000000000000000000,678680cb213c7204a56fe013fc9fe4cb6888cecc..853b12dba5bb02556ec1e87768a67fde5e797112
mode 000000,100644..100644
--- /dev/null
@@@ -1,0 -1,483 +1,483 @@@
 -      result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
+ /*
+  * Copyright (C) 2012 Intel Corporation
+  *    Author: Liu Jinsong <jinsong.liu@intel.com>
+  *    Author: Jiang Yunhong <yunhong.jiang@intel.com>
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or (at
+  * your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful, but
+  * WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+  * NON INFRINGEMENT.  See the GNU General Public License for more
+  * details.
+  */
+ #include <linux/kernel.h>
+ #include <linux/module.h>
+ #include <linux/init.h>
+ #include <linux/types.h>
+ #include <linux/acpi.h>
+ #include <acpi/acpi_drivers.h>
+ #include <xen/acpi.h>
+ #include <xen/interface/platform.h>
+ #include <asm/xen/hypercall.h>
+ #define PREFIX "ACPI:xen_memory_hotplug:"
+ struct acpi_memory_info {
+       struct list_head list;
+       u64 start_addr;         /* Memory Range start physical addr */
+       u64 length;             /* Memory Range length */
+       unsigned short caching; /* memory cache attribute */
+       unsigned short write_protect;   /* memory read/write attribute */
+                               /* copied from buffer getting from _CRS */
+       unsigned int enabled:1;
+ };
+ struct acpi_memory_device {
+       struct acpi_device *device;
+       struct list_head res_list;
+ };
+ static bool acpi_hotmem_initialized __read_mostly;
+ static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
+ {
+       int rc;
+       struct xen_platform_op op;
+       op.cmd = XENPF_mem_hotadd;
+       op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
+       op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
+       op.u.mem_add.pxm = pxm;
+       rc = HYPERVISOR_dom0_op(&op);
+       if (rc)
+               pr_err(PREFIX "Xen Hotplug Memory Add failed on "
+                       "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
+                       (unsigned long)info->start_addr,
+                       (unsigned long)(info->start_addr + info->length),
+                       pxm, rc);
+       return rc;
+ }
+ static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
+ {
+       int pxm, result;
+       int num_enabled = 0;
+       struct acpi_memory_info *info;
+       if (!mem_device)
+               return -EINVAL;
+       pxm = xen_acpi_get_pxm(mem_device->device->handle);
+       if (pxm < 0)
+               return pxm;
+       list_for_each_entry(info, &mem_device->res_list, list) {
+               if (info->enabled) { /* just sanity check...*/
+                       num_enabled++;
+                       continue;
+               }
+               if (!info->length)
+                       continue;
+               result = xen_hotadd_memory(pxm, info);
+               if (result)
+                       continue;
+               info->enabled = 1;
+               num_enabled++;
+       }
+       if (!num_enabled)
+               return -ENODEV;
+       return 0;
+ }
+ static acpi_status
+ acpi_memory_get_resource(struct acpi_resource *resource, void *context)
+ {
+       struct acpi_memory_device *mem_device = context;
+       struct acpi_resource_address64 address64;
+       struct acpi_memory_info *info, *new;
+       acpi_status status;
+       status = acpi_resource_to_address64(resource, &address64);
+       if (ACPI_FAILURE(status) ||
+           (address64.resource_type != ACPI_MEMORY_RANGE))
+               return AE_OK;
+       list_for_each_entry(info, &mem_device->res_list, list) {
+               if ((info->caching == address64.info.mem.caching) &&
+                   (info->write_protect == address64.info.mem.write_protect) &&
+                   (info->start_addr + info->length == address64.minimum)) {
+                       info->length += address64.address_length;
+                       return AE_OK;
+               }
+       }
+       new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
+       if (!new)
+               return AE_ERROR;
+       INIT_LIST_HEAD(&new->list);
+       new->caching = address64.info.mem.caching;
+       new->write_protect = address64.info.mem.write_protect;
+       new->start_addr = address64.minimum;
+       new->length = address64.address_length;
+       list_add_tail(&new->list, &mem_device->res_list);
+       return AE_OK;
+ }
+ static int
+ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
+ {
+       acpi_status status;
+       struct acpi_memory_info *info, *n;
+       if (!list_empty(&mem_device->res_list))
+               return 0;
+       status = acpi_walk_resources(mem_device->device->handle,
+               METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
+       if (ACPI_FAILURE(status)) {
+               list_for_each_entry_safe(info, n, &mem_device->res_list, list)
+                       kfree(info);
+               INIT_LIST_HEAD(&mem_device->res_list);
+               return -EINVAL;
+       }
+       return 0;
+ }
+ 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;
+       if (!acpi_bus_get_device(handle, &device) && device)
+               goto end;
+       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;
+       }
+       /*
+        * Now add the notified device.  This creates the acpi_device
+        * and invokes .add function
+        */
 -static int xen_acpi_memory_device_remove(struct acpi_device *device, int type)
++      result = acpi_bus_scan(handle);
+       if (result) {
+               pr_warn(PREFIX "Cannot add acpi bus\n");
+               return -EINVAL;
+       }
+ end:
+       *mem_device = acpi_driver_data(device);
+       if (!(*mem_device)) {
+               pr_err(PREFIX "Driver data not found\n");
+               return -ENODEV;
+       }
+       return 0;
+ }
+ static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
+ {
+       unsigned long long current_status;
+       /* Get device present/absent information from the _STA */
+       if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
+                               "_STA", NULL, &current_status)))
+               return -ENODEV;
+       /*
+        * Check for device status. Device should be
+        * present/enabled/functioning.
+        */
+       if (!((current_status & ACPI_STA_DEVICE_PRESENT)
+             && (current_status & ACPI_STA_DEVICE_ENABLED)
+             && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
+               return -ENODEV;
+       return 0;
+ }
+ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+ {
+       pr_debug(PREFIX "Xen does not support memory hotremove\n");
+       return -ENOSYS;
+ }
+ static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
+ {
+       struct acpi_memory_device *mem_device;
+       struct acpi_device *device;
+       u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
+       switch (event) {
+       case ACPI_NOTIFY_BUS_CHECK:
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                       "\nReceived BUS CHECK notification for device\n"));
+               /* Fall Through */
+       case ACPI_NOTIFY_DEVICE_CHECK:
+               if (event == ACPI_NOTIFY_DEVICE_CHECK)
+                       ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                       "\nReceived DEVICE CHECK notification for device\n"));
+               if (acpi_memory_get_device(handle, &mem_device)) {
+                       pr_err(PREFIX "Cannot find driver data\n");
+                       break;
+               }
+               ost_code = ACPI_OST_SC_SUCCESS;
+               break;
+       case ACPI_NOTIFY_EJECT_REQUEST:
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                       "\nReceived EJECT REQUEST notification for device\n"));
+               if (acpi_bus_get_device(handle, &device)) {
+                       pr_err(PREFIX "Device doesn't exist\n");
+                       break;
+               }
+               mem_device = acpi_driver_data(device);
+               if (!mem_device) {
+                       pr_err(PREFIX "Driver Data is NULL\n");
+                       break;
+               }
+               /*
+                * TBD: implement acpi_memory_disable_device and invoke
+                * acpi_bus_remove if Xen support hotremove in the future
+                */
+               acpi_memory_disable_device(mem_device);
+               break;
+       default:
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                                 "Unsupported event [0x%x]\n", event));
+               /* non-hotplug event; possibly handled by other handler */
+               return;
+       }
+       (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
+       return;
+ }
+ static int xen_acpi_memory_device_add(struct acpi_device *device)
+ {
+       int result;
+       struct acpi_memory_device *mem_device = NULL;
+       if (!device)
+               return -EINVAL;
+       mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
+       if (!mem_device)
+               return -ENOMEM;
+       INIT_LIST_HEAD(&mem_device->res_list);
+       mem_device->device = device;
+       sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
+       sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
+       device->driver_data = mem_device;
+       /* Get the range from the _CRS */
+       result = acpi_memory_get_device_resources(mem_device);
+       if (result) {
+               kfree(mem_device);
+               return result;
+       }
+       /*
+        * For booting existed memory devices, early boot code has recognized
+        * memory area by EFI/E820. If DSDT shows these memory devices on boot,
+        * hotplug is not necessary for them.
+        * For hot-added memory devices during runtime, it need hypercall to
+        * Xen hypervisor to add memory.
+        */
+       if (!acpi_hotmem_initialized)
+               return 0;
+       if (!acpi_memory_check_device(mem_device))
+               result = xen_acpi_memory_enable_device(mem_device);
+       return result;
+ }
++static int xen_acpi_memory_device_remove(struct acpi_device *device)
+ {
+       struct acpi_memory_device *mem_device = NULL;
+       if (!device || !acpi_driver_data(device))
+               return -EINVAL;
+       mem_device = acpi_driver_data(device);
+       kfree(mem_device);
+       return 0;
+ }
+ /*
+  * Helper function to check for memory device
+  */
+ static acpi_status is_memory_device(acpi_handle handle)
+ {
+       char *hardware_id;
+       acpi_status status;
+       struct acpi_device_info *info;
+       status = acpi_get_object_info(handle, &info);
+       if (ACPI_FAILURE(status))
+               return status;
+       if (!(info->valid & ACPI_VALID_HID)) {
+               kfree(info);
+               return AE_ERROR;
+       }
+       hardware_id = info->hardware_id.string;
+       if ((hardware_id == NULL) ||
+           (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
+               status = AE_ERROR;
+       kfree(info);
+       return status;
+ }
+ static acpi_status
+ acpi_memory_register_notify_handler(acpi_handle handle,
+                                   u32 level, void *ctxt, void **retv)
+ {
+       acpi_status status;
+       status = is_memory_device(handle);
+       if (ACPI_FAILURE(status))
+               return AE_OK;   /* continue */
+       status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+                                            acpi_memory_device_notify, NULL);
+       /* continue */
+       return AE_OK;
+ }
+ static acpi_status
+ acpi_memory_deregister_notify_handler(acpi_handle handle,
+                                     u32 level, void *ctxt, void **retv)
+ {
+       acpi_status status;
+       status = is_memory_device(handle);
+       if (ACPI_FAILURE(status))
+               return AE_OK;   /* continue */
+       status = acpi_remove_notify_handler(handle,
+                                           ACPI_SYSTEM_NOTIFY,
+                                           acpi_memory_device_notify);
+       return AE_OK;   /* continue */
+ }
+ static const struct acpi_device_id memory_device_ids[] = {
+       {ACPI_MEMORY_DEVICE_HID, 0},
+       {"", 0},
+ };
+ MODULE_DEVICE_TABLE(acpi, memory_device_ids);
+ static struct acpi_driver xen_acpi_memory_device_driver = {
+       .name = "acpi_memhotplug",
+       .class = ACPI_MEMORY_DEVICE_CLASS,
+       .ids = memory_device_ids,
+       .ops = {
+               .add = xen_acpi_memory_device_add,
+               .remove = xen_acpi_memory_device_remove,
+               },
+ };
+ static int __init xen_acpi_memory_device_init(void)
+ {
+       int result;
+       acpi_status status;
+       if (!xen_initial_domain())
+               return -ENODEV;
+       /* unregister the stub which only used to reserve driver space */
+       xen_stub_memory_device_exit();
+       result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
+       if (result < 0) {
+               xen_stub_memory_device_init();
+               return -ENODEV;
+       }
+       status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                                    ACPI_UINT32_MAX,
+                                    acpi_memory_register_notify_handler,
+                                    NULL, NULL, NULL);
+       if (ACPI_FAILURE(status)) {
+               pr_warn(PREFIX "walk_namespace failed\n");
+               acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
+               xen_stub_memory_device_init();
+               return -ENODEV;
+       }
+       acpi_hotmem_initialized = true;
+       return 0;
+ }
+ static void __exit xen_acpi_memory_device_exit(void)
+ {
+       acpi_status status;
+       if (!xen_initial_domain())
+               return;
+       status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                                    ACPI_UINT32_MAX,
+                                    acpi_memory_deregister_notify_handler,
+                                    NULL, NULL, NULL);
+       if (ACPI_FAILURE(status))
+               pr_warn(PREFIX "walk_namespace failed\n");
+       acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
+       /*
+        * stub reserve space again to prevent any chance of native
+        * driver loading.
+        */
+       xen_stub_memory_device_init();
+       return;
+ }
+ module_init(xen_acpi_memory_device_init);
+ module_exit(xen_acpi_memory_device_exit);
+ ACPI_MODULE_NAME("xen-acpi-memhotplug");
+ MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
+ MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
+ MODULE_LICENSE("GPL");