1 files changed, 542 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
new file mode 100644
index 000000000000..77285ffe41c5
--- /dev/null
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -0,0 +1,542 @@
+/*
+ * Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
+ *
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * ACPI based HotPlug driver that supports Memory Hotplug
+ * This driver fields notifications from firmare for memory add
+ * and remove operations and alerts the VM of the affected memory
+ * ranges.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/memory_hotplug.h>
+#include <acpi/acpi_drivers.h>
+
+
+#define ACPI_MEMORY_DEVICE_COMPONENT            0x08000000UL
+#define ACPI_MEMORY_DEVICE_CLASS                "memory"
+#define ACPI_MEMORY_DEVICE_HID                  "PNP0C80"
+#define ACPI_MEMORY_DEVICE_DRIVER_NAME          "Hotplug Mem Driver"
+#define ACPI_MEMORY_DEVICE_NAME                 "Hotplug Mem Device"
+
+#define _COMPONENT              ACPI_MEMORY_DEVICE_COMPONENT
+
+ACPI_MODULE_NAME                ("acpi_memory")
+MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
+MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
+MODULE_LICENSE("GPL");
+
+/* ACPI _STA method values */
+#define ACPI_MEMORY_STA_PRESENT         (0x00000001UL)
+#define ACPI_MEMORY_STA_ENABLED         (0x00000002UL)
+#define ACPI_MEMORY_STA_FUNCTIONAL      (0x00000008UL)
+
+/* Memory Device States */
+#define MEMORY_INVALID_STATE    0
+#define MEMORY_POWER_ON_STATE   1
+#define MEMORY_POWER_OFF_STATE  2
+
+static int acpi_memory_device_add (struct acpi_device *device);
+static int acpi_memory_device_remove (struct acpi_device *device, int type);
+
+static struct acpi_driver acpi_memory_device_driver = {
+        .name =         ACPI_MEMORY_DEVICE_DRIVER_NAME,
+        .class =        ACPI_MEMORY_DEVICE_CLASS,
+        .ids =          ACPI_MEMORY_DEVICE_HID,
+        .ops =          {
+                                .add =          acpi_memory_device_add,
+                                .remove =       acpi_memory_device_remove,
+                        },
+};
+
+struct acpi_memory_device {
+        acpi_handle handle;
+        unsigned int state;             /* State of the memory device */
+        unsigned short cache_attribute; /* memory cache attribute */
+        unsigned short read_write_attribute;/* memory read/write attribute */
+        u64 start_addr; /* Memory Range start physical addr */
+        u64 end_addr;   /* Memory Range end physical addr */
+};
+
+
+static int
+acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
+{
+        acpi_status status;
+        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+        struct acpi_resource *resource = NULL;
+        struct acpi_resource_address64 address64;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
+
+        /* Get the range from the _CRS */
+        status = acpi_get_current_resources(mem_device->handle, &buffer);
+        if (ACPI_FAILURE(status))
+                return_VALUE(-EINVAL);
+
+        resource = (struct acpi_resource *) buffer.pointer;
+        status = acpi_resource_to_address64(resource, &address64);
+        if (ACPI_SUCCESS(status)) {
+                if (address64.resource_type == ACPI_MEMORY_RANGE) {
+                        /* Populate the structure */
+                        mem_device->cache_attribute =
+                                address64.attribute.memory.cache_attribute;
+                        mem_device->read_write_attribute =
+                        address64.attribute.memory.read_write_attribute;
+                        mem_device->start_addr = address64.min_address_range;
+                        mem_device->end_addr = address64.max_address_range;
+                }
+        }
+
+        acpi_os_free(buffer.pointer);
+        return_VALUE(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;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_get_device");
+
+        if (!acpi_bus_get_device(handle, &device) && device)
+                goto end;
+
+        status = acpi_get_parent(handle, &phandle);
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                        "Error in acpi_get_parent\n"));
+                return_VALUE(-EINVAL);
+        }
+
+        /* Get the parent device */
+        status = acpi_bus_get_device(phandle, &pdevice);
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                        "Error in acpi_bus_get_device\n"));
+                return_VALUE(-EINVAL);
+        }
+
+        /*
+         * Now add the notified device.  This creates the acpi_device
+         * and invokes .add function
+         */
+        status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                        "Error in acpi_bus_add\n"));
+                return_VALUE(-EINVAL);
+        }
+
+end:
+        *mem_device = acpi_driver_data(device);
+        if (!(*mem_device)) {
+                printk(KERN_ERR "\n driver data not found" );
+                return_VALUE(-ENODEV);
+        }
+
+        return_VALUE(0);
+}
+
+static int
+acpi_memory_check_device(struct acpi_memory_device *mem_device)
+{
+        unsigned long current_status;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_check_device");
+
+        /* Get device present/absent information from the _STA */
+        if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
+                NULL, &current_status)))
+                return_VALUE(-ENODEV);
+        /*
+         * Check for device status. Device should be
+         * present/enabled/functioning.
+         */
+        if (!((current_status & ACPI_MEMORY_STA_PRESENT)
+                && (current_status & ACPI_MEMORY_STA_ENABLED)
+                && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
+                return_VALUE(-ENODEV);
+
+        return_VALUE(0);
+}
+
+static int
+acpi_memory_enable_device(struct acpi_memory_device *mem_device)
+{
+        int result;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
+
+        /* Get the range from the _CRS */
+        result = acpi_memory_get_device_resources(mem_device);
+        if (result) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                        "\nget_device_resources failed\n"));
+                mem_device->state = MEMORY_INVALID_STATE;
+                return result;
+        }
+
+        /*
+         * Tell the VM there is more memory here...
+         * Note: Assume that this function returns zero on success
+         */
+        result = add_memory(mem_device->start_addr,
+                        (mem_device->end_addr - mem_device->start_addr) + 1,
+                        mem_device->read_write_attribute);
+        if (result) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                        "\nadd_memory failed\n"));
+                mem_device->state = MEMORY_INVALID_STATE;
+                return result;
+        }
+
+        return result;
+}
+
+static int
+acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
+{
+        acpi_status status;
+        struct acpi_object_list arg_list;
+        union acpi_object arg;
+        unsigned long current_status;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
+
+        /* Issue the _EJ0 command */
+        arg_list.count = 1;
+        arg_list.pointer = &arg;
+        arg.type = ACPI_TYPE_INTEGER;
+        arg.integer.value = 1;
+        status = acpi_evaluate_object(mem_device->handle,
+                        "_EJ0", &arg_list, NULL);
+        /* Return on _EJ0 failure */
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"_EJ0 failed.\n"));
+                return_VALUE(-ENODEV);
+        }
+
+        /* Evalute _STA to check if the device is disabled */
+        status = acpi_evaluate_integer(mem_device->handle, "_STA",
+                NULL, &current_status);
+        if (ACPI_FAILURE(status))
+                return_VALUE(-ENODEV);
+
+        /* Check for device status.  Device should be disabled */
+        if (current_status & ACPI_MEMORY_STA_ENABLED)
+                return_VALUE(-EINVAL);
+
+        return_VALUE(0);
+}
+
+static int
+acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+{
+        int result;
+        u64 start = mem_device->start_addr;
+        u64 len = mem_device->end_addr - start + 1;
+        unsigned long attr = mem_device->read_write_attribute;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
+
+        /*
+         * Ask the VM to offline this memory range.
+         * Note: Assume that this function returns zero on success
+         */
+        result = remove_memory(start, len, attr);
+        if (result) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Hot-Remove failed.\n"));
+                return_VALUE(result);
+        }
+
+        /* Power-off and eject the device */
+        result = acpi_memory_powerdown_device(mem_device);
+        if (result) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                        "Device Power Down failed.\n"));
+                /* Set the status of the device to invalid */
+                mem_device->state = MEMORY_INVALID_STATE;
+                return result;
+        }
+
+        mem_device->state = MEMORY_POWER_OFF_STATE;
+        return result;
+}
+
+static void
+acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
+{
+        struct acpi_memory_device *mem_device;
+        struct acpi_device *device;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
+
+        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)) {
+                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                "Error in finding driver data\n"));
+                        return_VOID;
+                }
+
+                if (!acpi_memory_check_device(mem_device)) {
+                        if (acpi_memory_enable_device(mem_device))
+                                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                "Error in acpi_memory_enable_device\n"));
+                }
+                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)) {
+                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                        "Device doesn't exist\n"));
+                        break;
+                }
+                mem_device = acpi_driver_data(device);
+                if (!mem_device) {
+                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                        "Driver Data is NULL\n"));
+                        break;
+                }
+
+                /*
+                 * Currently disabling memory device from kernel mode
+                 * TBD: Can also be disabled from user mode scripts
+                 * TBD: Can also be disabled by Callback registration
+                 *      with generic sysfs driver
+                 */
+                if (acpi_memory_disable_device(mem_device))
+                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                "Error in acpi_memory_disable_device\n"));
+                /*
+                 * TBD: Invoke acpi_bus_remove to cleanup data structures
+                 */
+                break;
+        default:
+                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                        "Unsupported event [0x%x]\n", event));
+                break;
+        }
+
+        return_VOID;
+}
+
+static int
+acpi_memory_device_add(struct acpi_device *device)
+{
+        int result;
+        struct acpi_memory_device *mem_device = NULL;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_device_add");
+
+        if (!device)
+                return_VALUE(-EINVAL);
+
+        mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
+        if (!mem_device)
+                return_VALUE(-ENOMEM);
+        memset(mem_device, 0, sizeof(struct acpi_memory_device));
+
+        mem_device->handle = device->handle;
+        sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
+        sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
+        acpi_driver_data(device) = mem_device;
+
+        /* Get the range from the _CRS */
+        result = acpi_memory_get_device_resources(mem_device);
+        if (result) {
+                kfree(mem_device);
+                return_VALUE(result);
+        }
+
+        /* Set the device state */
+        mem_device->state = MEMORY_POWER_ON_STATE;
+
+        printk(KERN_INFO "%s \n", acpi_device_name(device));
+
+        return_VALUE(result);
+}
+
+static int
+acpi_memory_device_remove (struct acpi_device *device, int type)
+{
+        struct acpi_memory_device *mem_device = NULL;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
+
+        if (!device || !acpi_driver_data(device))
+                return_VALUE(-EINVAL);
+
+        mem_device = (struct acpi_memory_device *) acpi_driver_data(device);
+        kfree(mem_device);
+
+        return_VALUE(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_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+        struct acpi_device_info *info;
+
+        ACPI_FUNCTION_TRACE("is_memory_device");
+
+        status = acpi_get_object_info(handle, &buffer);
+        if (ACPI_FAILURE(status))
+                return_ACPI_STATUS(AE_ERROR);
+
+        info = buffer.pointer;
+        if (!(info->valid & ACPI_VALID_HID)) {
+                acpi_os_free(buffer.pointer);
+                return_ACPI_STATUS(AE_ERROR);
+        }
+
+        hardware_id = info->hardware_id.value;
+        if ((hardware_id == NULL) ||
+                (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
+                status = AE_ERROR;
+
+        acpi_os_free(buffer.pointer);
+        return_ACPI_STATUS(status);
+}
+
+static acpi_status
+acpi_memory_register_notify_handler (acpi_handle handle,
+        u32 level, void *ctxt, void **retv)
+{
+        acpi_status status;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
+
+        status = is_memory_device(handle);
+        if (ACPI_FAILURE(status))
+                return_ACPI_STATUS(AE_OK);      /* continue */
+
+        status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+                        acpi_memory_device_notify, NULL);
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                        "Error installing notify handler\n"));
+                return_ACPI_STATUS(AE_OK);      /* continue */
+        }
+
+        return_ACPI_STATUS(status);
+}
+
+static acpi_status
+acpi_memory_deregister_notify_handler (acpi_handle handle,
+                               u32 level, void *ctxt, void **retv)
+{
+        acpi_status status;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
+
+        status = is_memory_device(handle);
+        if (ACPI_FAILURE(status))
+                return_ACPI_STATUS(AE_OK);      /* continue */
+
+        status = acpi_remove_notify_handler(handle,
+                        ACPI_SYSTEM_NOTIFY, acpi_memory_device_notify);
+        if (ACPI_FAILURE(status)) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                "Error removing notify handler\n"));
+                return_ACPI_STATUS(AE_OK);      /* continue */
+        }
+
+        return_ACPI_STATUS(status);
+}
+
+static int __init
+acpi_memory_device_init (void)
+{
+        int result;
+        acpi_status status;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_device_init");
+
+        result = acpi_bus_register_driver(&acpi_memory_device_driver);
+
+        if (result < 0)
+                return_VALUE(-ENODEV);
+
+        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                                ACPI_UINT32_MAX,
+                                acpi_memory_register_notify_handler,
+                                NULL, NULL);
+
+        if (ACPI_FAILURE (status)) {
+                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "walk_namespace failed\n"));
+                acpi_bus_unregister_driver(&acpi_memory_device_driver);
+                return_VALUE(-ENODEV);
+        }
+
+        return_VALUE(0);
+}
+
+static void __exit
+acpi_memory_device_exit (void)
+{
+        acpi_status status;
+
+        ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
+
+        /*
+         * Adding this to un-install notification handlers for all the device
+         * handles.
+         */
+        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+                        ACPI_UINT32_MAX,
+                        acpi_memory_deregister_notify_handler,
+                        NULL, NULL);
+
+        if (ACPI_FAILURE (status))
+                ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "walk_namespace failed\n"));
+
+        acpi_bus_unregister_driver(&acpi_memory_device_driver);
+
+        return_VOID;
+}
+
+module_init(acpi_memory_device_init);
+module_exit(acpi_memory_device_exit);
+
+