/* * 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 caching; /* memory cache attribute */ unsigned short write_protect; /* 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->caching = address64.info.mem.caching; mem_device->write_protect = address64.info.mem.write_protect; mem_device->start_addr = address64.minimum; mem_device->end_addr = address64.maximum; } } 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); 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; 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); 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);