// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2004, 2013 Intel Corporation * Author: Naveen B S <naveen.b.s@intel.com> * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> * * All rights reserved. * * 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/acpi.h> #include <linux/memory.h> #include <linux/memory_hotplug.h> #include "internal.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 #undef PREFIX #define PREFIX "ACPI:memory_hp:" ACPI_MODULE_NAME("acpi_memhotplug"); static const struct acpi_device_id memory_device_ids[] = { {ACPI_MEMORY_DEVICE_HID, 0}, {"", 0}, }; #ifdef CONFIG_ACPI_HOTPLUG_MEMORY /* 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, const struct acpi_device_id *not_used); static void acpi_memory_device_remove(struct acpi_device *device); static struct acpi_scan_handler memory_device_handler = { .ids = memory_device_ids, .attach = acpi_memory_device_add, .detach = acpi_memory_device_remove, .hotplug = { .enabled = true, }, }; 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 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.address.minimum)) { info->length += address64.address.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.address.minimum; new->length = address64.address.address_length; list_add_tail(&new->list, &mem_device->res_list); return AE_OK; } static void acpi_memory_free_device_resources(struct acpi_memory_device *mem_device) { struct acpi_memory_info *info, *n; list_for_each_entry_safe(info, n, &mem_device->res_list, list) kfree(info); INIT_LIST_HEAD(&mem_device->res_list); } static int acpi_memory_get_device_resources(struct acpi_memory_device *mem_device) { acpi_status status; 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)) { acpi_memory_free_device_resources(mem_device); return -EINVAL; } 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, METHOD_NAME__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_bind_memblk(struct memory_block *mem, void *arg) { return acpi_bind_one(&mem->dev, arg); } static int acpi_bind_memory_blocks(struct acpi_memory_info *info, struct acpi_device *adev) { return walk_memory_blocks(info->start_addr, info->length, adev, acpi_bind_memblk); } static int acpi_unbind_memblk(struct memory_block *mem, void *arg) { acpi_unbind_one(&mem->dev); return 0; } static void acpi_unbind_memory_blocks(struct acpi_memory_info *info) { walk_memory_blocks(info->start_addr, info->length, NULL, acpi_unbind_memblk); } static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) { acpi_handle handle = mem_device->device->handle; int result, num_enabled = 0; struct acpi_memory_info *info; int node; node = acpi_get_node(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 the memory block size is zero, please ignore it. * Don't try to do the following memory hotplug flowchart. */ if (!info->length) continue; if (node < 0) node = memory_add_physaddr_to_nid(info->start_addr); result = __add_memory(node, info->start_addr, info->length); /* * If the memory block has been used by the kernel, add_memory() * returns -EEXIST. If add_memory() returns the other error, it * means that this memory block is not used by the kernel. */ if (result && result != -EEXIST) continue; result = acpi_bind_memory_blocks(info, mem_device->device); if (result) { acpi_unbind_memory_blocks(info); return -ENODEV; } info->enabled = 1; /* * Add num_enable even if add_memory() returns -EEXIST, so the * device is bound to this driver. */ num_enabled++; } if (!num_enabled) { dev_err(&mem_device->device->dev, "add_memory failed\n"); mem_device->state = MEMORY_INVALID_STATE; return -EINVAL; } /* * Sometimes the memory device will contain several memory blocks. * When one memory block is hot-added to the system memory, it will * be regarded as a success. * Otherwise if the last memory block can't be hot-added to the system * memory, it will be failure and the memory device can't be bound with * driver. */ return 0; } static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device) { acpi_handle handle = mem_device->device->handle; struct acpi_memory_info *info, *n; int nid = acpi_get_node(handle); list_for_each_entry_safe(info, n, &mem_device->res_list, list) { if (!info->enabled) continue; if (nid == NUMA_NO_NODE) nid = memory_add_physaddr_to_nid(info->start_addr); acpi_unbind_memory_blocks(info); __remove_memory(nid, info->start_addr, info->length); list_del(&info->list); kfree(info); } } static void acpi_memory_device_free(struct acpi_memory_device *mem_device) { if (!mem_device) return; acpi_memory_free_device_resources(mem_device); mem_device->device->driver_data = NULL; kfree(mem_device); } static int acpi_memory_device_add(struct acpi_device *device, const struct acpi_device_id *not_used) { struct acpi_memory_device *mem_device; int result; 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) { device->driver_data = NULL; kfree(mem_device); return result; } /* Set the device state */ mem_device->state = MEMORY_POWER_ON_STATE; result = acpi_memory_check_device(mem_device); if (result) { acpi_memory_device_free(mem_device); return 0; } result = acpi_memory_enable_device(mem_device); if (result) { dev_err(&device->dev, "acpi_memory_enable_device() error\n"); acpi_memory_device_free(mem_device); return result; } dev_dbg(&device->dev, "Memory device configured by ACPI\n"); return 1; } static void acpi_memory_device_remove(struct acpi_device *device) { struct acpi_memory_device *mem_device; if (!device || !acpi_driver_data(device)) return; mem_device = acpi_driver_data(device); acpi_memory_remove_memory(mem_device); acpi_memory_device_free(mem_device); } static bool __initdata acpi_no_memhotplug; void __init acpi_memory_hotplug_init(void) { if (acpi_no_memhotplug) { memory_device_handler.attach = NULL; acpi_scan_add_handler(&memory_device_handler); return; } acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory"); } static int __init disable_acpi_memory_hotplug(char *str) { acpi_no_memhotplug = true; return 1; } __setup("acpi_no_memhotplug", disable_acpi_memory_hotplug); #else static struct acpi_scan_handler memory_device_handler = { .ids = memory_device_ids, }; void __init acpi_memory_hotplug_init(void) { acpi_scan_add_handler(&memory_device_handler); } #endif /* CONFIG_ACPI_HOTPLUG_MEMORY */