diff options
Diffstat (limited to 'drivers/acpi/acpi_memhotplug.c')
| -rw-r--r-- | drivers/acpi/acpi_memhotplug.c | 577 |
1 files changed, 577 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c new file mode 100644 index 00000000..d9857138 --- /dev/null +++ b/drivers/acpi/acpi_memhotplug.c @@ -0,0 +1,577 @@ +/* + * 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 <linux/slab.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 + +#undef PREFIX +#define PREFIX "ACPI:memory_hp:" + +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 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, + }, +}; + +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; + int result; + + + 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 */ + result = acpi_bus_get_device(phandle, &pdevice); + if (result) { + printk(KERN_WARNING PREFIX "Cannot get acpi bus device"); + return -EINVAL; + } + + /* + * Now add the notified device. This creates the acpi_device + * and invokes .add function + */ + result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE); + if (result) { + printk(KERN_WARNING PREFIX "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 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 (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; + } + /* + * 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 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)); + + /* + * 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; + + 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; +} + +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; +} + +/* + * Helper function to check for memory device + */ +static acpi_status is_memory_device(acpi_handle handle) +{ + char *hardware_id; + acpi_status status; + struct acpi_device_info *info; + + status = acpi_get_object_info(handle, &info); + if (ACPI_FAILURE(status)) + return status; + + if (!(info->valid & ACPI_VALID_HID)) { + kfree(info); + return AE_ERROR; + } + + hardware_id = info->hardware_id.string; + if ((hardware_id == NULL) || + (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID))) + status = AE_ERROR; + + kfree(info); + 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, 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, 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); |