--- /dev/null
+/*
+ * 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, ¤t_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, ¤t_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);
+
+
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