/* * 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 firmware 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_CLASS "memory" #define ACPI_MEMORY_DEVICE_HID "PNP0C80" #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device" #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT ACPI_MODULE_NAME("acpi_memhotplug"); MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>"); MODULE_DESCRIPTION("Hotplug Mem Driver"); MODULE_LICENSE("GPL"); /* 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 int acpi_memory_device_start(struct acpi_device *device); 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 acpi_memory_device_driver = { .name = "acpi_memhotplug", .class = ACPI_MEMORY_DEVICE_CLASS, .ids = memory_device_ids, .ops = { .add = acpi_memory_device_add, .remove = acpi_memory_device_remove, .start = acpi_memory_device_start, }, }; 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 */ unsigned int enabled:1; }; struct acpi_memory_device { struct acpi_device * device; unsigned int state; /* State of the memory device */ struct list_head res_list; }; static int acpi_hotmem_initialized; 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) { /* Can we combine the resource range information? */ 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; if (!acpi_bus_get_device(handle, &device) && device) goto end; status = acpi_get_parent(handle, &phandle); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent")); return -EINVAL; } /* Get the parent device */ status = acpi_bus_get_device(phandle, &pdevice); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device")); return -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_EXCEPTION((AE_INFO, status, "Cannot add acpi bus")); return -EINVAL; } end: *mem_device = acpi_driver_data(device); if (!(*mem_device)) { printk(KERN_ERR "\n driver data not found"); 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, ¤t_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_enable_device(struct acpi_memory_device *mem_device) { int result, num_enabled = 0; struct acpi_memory_info *info; int node; /* Get the range from the _CRS */ result = acpi_memory_get_device_resources(mem_device); if (result) { printk(KERN_ERR PREFIX "get_device_resources failed\n"); mem_device->state = MEMORY_INVALID_STATE; return result; } node = acpi_get_node(mem_device->device->handle); /* * Tell the VM there is more memory here... * Note: Assume that this function returns zero on success * We don't have memory-hot-add rollback function,now. * (i.e. memory-hot-remove function) */ list_for_each_entry(info, &mem_device->res_list, list) { if (info->enabled) { /* just sanity check...*/ num_enabled++; continue; } if (node < 0) node = memory_add_physaddr_to_nid(info->start_addr); result = add_memory(node, info->start_addr, info->length); if (result) continue; info->enabled = 1; num_enabled++; } if (!num_enabled) { printk(KERN_ERR PREFIX "add_memory failed\n"); mem_device->state = MEMORY_INVALID_STATE; return -EINVAL; } 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 long current_status; /* 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->device->handle, "_EJ0", &arg_list, NULL); /* Return on _EJ0 failure */ if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed")); return -ENODEV; } /* Evalute _STA to check if the device is disabled */ status = acpi_evaluate_integer(mem_device->device->handle, "_STA", NULL, ¤t_status); if (ACPI_FAILURE(status)) return -ENODEV; /* Check for device status. Device should be disabled */ if (current_status & ACPI_STA_DEVICE_ENABLED) return -EINVAL; return 0; } static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) { int result; struct acpi_memory_info *info, *n; /* * Ask the VM to offline this memory range. * Note: Assume that this function returns zero on success */ list_for_each_entry_safe(info, n, &mem_device->res_list, list) { if (info->enabled) { result = remove_memory(info->start_addr, info->length); if (result) return result; } kfree(info); } /* Power-off and eject the device */ result = acpi_memory_powerdown_device(mem_device); if (result) { /* 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; 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)) { printk(KERN_ERR PREFIX "Cannot find driver data\n"); return; } if (!acpi_memory_check_device(mem_device)) { if (acpi_memory_enable_device(mem_device)) printk(KERN_ERR PREFIX "Cannot enable memory 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)) { printk(KERN_ERR PREFIX "Device doesn't exist\n"); break; } mem_device = acpi_driver_data(device); if (!mem_device) { printk(KERN_ERR PREFIX "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)) printk(KERN_ERR PREFIX "Disable memory 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; } static int 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; } /* Set the device state */ mem_device->state = MEMORY_POWER_ON_STATE; printk(KERN_DEBUG "%s \n", acpi_device_name(device)); return result; } static int 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; } static int acpi_memory_device_start (struct acpi_device *device) { struct acpi_memory_device *mem_device; int result = 0; /* * Early boot code has recognized memory area by EFI/E820. * If DSDT shows these memory devices on boot, hotplug is not necessary * for them. So, it just returns until completion of this driver's * start up. */ if (!acpi_hotmem_initialized) return 0; mem_device = acpi_driver_data(device); if (!acpi_memory_check_device(mem_device)) { /* call add_memory func */ result = acpi_memory_enable_device(mem_device); if (result) printk(KERN_ERR PREFIX "Error in acpi_memory_enable_device\n"); } return result; } /* * 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; status = acpi_get_object_info(handle, &buffer); if (ACPI_FAILURE(status)) return status; info = buffer.pointer; if (!(info->valid & ACPI_VALID_HID)) { kfree(buffer.pointer); return AE_ERROR; } hardware_id = info->hardware_id.value; if ((hardware_id == NULL) || (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID))) status = AE_ERROR; kfree(buffer.pointer); 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 int __init acpi_memory_device_init(void) { int result; acpi_status status; result = acpi_bus_register_driver(&acpi_memory_device_driver); if (result < 0) return -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_EXCEPTION((AE_INFO, status, "walk_namespace failed")); acpi_bus_unregister_driver(&acpi_memory_device_driver); return -ENODEV; } acpi_hotmem_initialized = 1; return 0; } static void __exit acpi_memory_device_exit(void) { acpi_status status; /* * 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_EXCEPTION((AE_INFO, status, "walk_namespace failed")); acpi_bus_unregister_driver(&acpi_memory_device_driver); return; } module_init(acpi_memory_device_init); module_exit(acpi_memory_device_exit);