4 files changed, 522 insertions, 4 deletions

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index c1c8566c6840..dcffad1b47ca 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -191,6 +191,17 @@ config XEN_STUB
 
           To enable Xen features like cpu and memory hotplug, select Y here.
 
+config XEN_ACPI_HOTPLUG_MEMORY
+        tristate "Xen ACPI memory hotplug"
+        depends on XEN_DOM0 && XEN_STUB && ACPI
+        default n
+        help
+          This is Xen ACPI memory hotplug.
+
+          Currently Xen only support ACPI memory hot-add. If you want
+          to hot-add memory at runtime (the hot-added memory cannot be
+          removed until machine stop), select Y/M here, otherwise select N.
+
 config XEN_ACPI_PROCESSOR
         tristate "Xen ACPI processor"
         depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index b63edd824ad4..1605f594ff56 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_XEN_MCE_LOG)		+= mcelog.o
 obj-$(CONFIG_XEN_PCIDEV_BACKEND)        += xen-pciback/
 obj-$(CONFIG_XEN_PRIVCMD)               += xen-privcmd.o
 obj-$(CONFIG_XEN_STUB)                  += xen-stub.o
+obj-$(CONFIG_XEN_ACPI_HOTPLUG_MEMORY)   += xen-acpi-memhotplug.o
 obj-$(CONFIG_XEN_ACPI_PROCESSOR)        += xen-acpi-processor.o
 xen-evtchn-y                            := evtchn.o
 xen-gntdev-y                            := gntdev.o
diff --git a/drivers/xen/xen-acpi-memhotplug.c b/drivers/xen/xen-acpi-memhotplug.c
new file mode 100644
index 000000000000..2c3759ac10f0
--- /dev/null
+++ b/drivers/xen/xen-acpi-memhotplug.c
@@ -0,0 +1,501 @@
+/*
+ * 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_get_pxm(acpi_handle h)
+{
+        unsigned long long pxm;
+        acpi_status status;
+        acpi_handle handle;
+        acpi_handle phandle = h;
+
+        do {
+                handle = phandle;
+                status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
+                if (ACPI_SUCCESS(status))
+                        return pxm;
+                status = acpi_get_parent(handle, &phandle);
+        } while (ACPI_SUCCESS(status));
+
+        return -ENXIO;
+}
+
+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
+         */
+        result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
+        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, int type)
+{
+        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");
diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h
index 5e36932ab407..2c4fb4bb07df 100644
--- a/include/xen/interface/platform.h
+++ b/include/xen/interface/platform.h
@@ -324,10 +324,14 @@ struct xenpf_cpu_ol {
 };
 DEFINE_GUEST_HANDLE_STRUCT(xenpf_cpu_ol);
 
-/*
- * CMD 58 and 59 are reserved for cpu hotadd and memory hotadd,
- * which are already occupied at Xen hypervisor side.
- */
+#define XENPF_mem_hotadd        59
+struct xenpf_mem_hotadd {
+        uint64_t spfn;
+        uint64_t epfn;
+        uint32_t pxm;
+        uint32_t flags;
+};
+
 #define XENPF_core_parking     60
 struct xenpf_core_parking {
         /* IN variables */
@@ -357,6 +361,7 @@ struct xen_platform_op {
                 struct xenpf_set_processor_pminfo set_pminfo;
                 struct xenpf_pcpuinfo          pcpu_info;
                 struct xenpf_cpu_ol            cpu_ol;
+                struct xenpf_mem_hotadd        mem_add;
                 struct xenpf_core_parking      core_parking;
                 uint8_t                        pad[128];
         } u;