2 * Copyright (C) 2004 Intel Corporation <naveen.b.s@intel.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT. See the GNU General Public License for more
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 * ACPI based HotPlug driver that supports Memory Hotplug
23 * This driver fields notifications from firmware for memory add
24 * and remove operations and alerts the VM of the affected memory
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/memory_hotplug.h>
33 #include <linux/slab.h>
34 #include <linux/acpi.h>
35 #include <acpi/acpi_drivers.h>
37 #define ACPI_MEMORY_DEVICE_CLASS "memory"
38 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
39 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
41 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
44 #define PREFIX "ACPI:memory_hp:"
46 ACPI_MODULE_NAME("acpi_memhotplug");
47 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
48 MODULE_DESCRIPTION("Hotplug Mem Driver");
49 MODULE_LICENSE("GPL");
51 /* Memory Device States */
52 #define MEMORY_INVALID_STATE 0
53 #define MEMORY_POWER_ON_STATE 1
54 #define MEMORY_POWER_OFF_STATE 2
56 static int acpi_memory_device_add(struct acpi_device *device);
57 static int acpi_memory_device_remove(struct acpi_device *device, int type);
59 static const struct acpi_device_id memory_device_ids[] = {
60 {ACPI_MEMORY_DEVICE_HID, 0},
63 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
65 static struct acpi_driver acpi_memory_device_driver = {
66 .name = "acpi_memhotplug",
67 .class = ACPI_MEMORY_DEVICE_CLASS,
68 .ids = memory_device_ids,
70 .add = acpi_memory_device_add,
71 .remove = acpi_memory_device_remove,
75 struct acpi_memory_info {
76 struct list_head list;
77 u64 start_addr; /* Memory Range start physical addr */
78 u64 length; /* Memory Range length */
79 unsigned short caching; /* memory cache attribute */
80 unsigned short write_protect; /* memory read/write attribute */
81 unsigned int enabled:1;
82 unsigned int failed:1;
85 struct acpi_memory_device {
86 struct acpi_device * device;
87 unsigned int state; /* State of the memory device */
88 struct list_head res_list;
92 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
94 struct acpi_memory_device *mem_device = context;
95 struct acpi_resource_address64 address64;
96 struct acpi_memory_info *info, *new;
99 status = acpi_resource_to_address64(resource, &address64);
100 if (ACPI_FAILURE(status) ||
101 (address64.resource_type != ACPI_MEMORY_RANGE))
104 list_for_each_entry(info, &mem_device->res_list, list) {
105 /* Can we combine the resource range information? */
106 if ((info->caching == address64.info.mem.caching) &&
107 (info->write_protect == address64.info.mem.write_protect) &&
108 (info->start_addr + info->length == address64.minimum)) {
109 info->length += address64.address_length;
114 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
118 INIT_LIST_HEAD(&new->list);
119 new->caching = address64.info.mem.caching;
120 new->write_protect = address64.info.mem.write_protect;
121 new->start_addr = address64.minimum;
122 new->length = address64.address_length;
123 list_add_tail(&new->list, &mem_device->res_list);
129 acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
131 struct acpi_memory_info *info, *n;
133 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
135 INIT_LIST_HEAD(&mem_device->res_list);
139 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
143 if (!list_empty(&mem_device->res_list))
146 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
147 acpi_memory_get_resource, mem_device);
148 if (ACPI_FAILURE(status)) {
149 acpi_memory_free_device_resources(mem_device);
157 acpi_memory_get_device(acpi_handle handle,
158 struct acpi_memory_device **mem_device)
162 struct acpi_device *device = NULL;
163 struct acpi_device *pdevice = NULL;
167 if (!acpi_bus_get_device(handle, &device) && device)
170 status = acpi_get_parent(handle, &phandle);
171 if (ACPI_FAILURE(status)) {
172 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
176 /* Get the parent device */
177 result = acpi_bus_get_device(phandle, &pdevice);
179 acpi_handle_warn(phandle, "Cannot get acpi bus device\n");
184 * Now add the notified device. This creates the acpi_device
185 * and invokes .add function
187 result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
189 acpi_handle_warn(handle, "Cannot add acpi bus\n");
194 *mem_device = acpi_driver_data(device);
195 if (!(*mem_device)) {
196 dev_err(&device->dev, "driver data not found\n");
203 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
205 unsigned long long current_status;
207 /* Get device present/absent information from the _STA */
208 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
209 NULL, ¤t_status)))
212 * Check for device status. Device should be
213 * present/enabled/functioning.
215 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
216 && (current_status & ACPI_STA_DEVICE_ENABLED)
217 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
223 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
225 int result, num_enabled = 0;
226 struct acpi_memory_info *info;
229 node = acpi_get_node(mem_device->device->handle);
231 * Tell the VM there is more memory here...
232 * Note: Assume that this function returns zero on success
233 * We don't have memory-hot-add rollback function,now.
234 * (i.e. memory-hot-remove function)
236 list_for_each_entry(info, &mem_device->res_list, list) {
237 if (info->enabled) { /* just sanity check...*/
242 * If the memory block size is zero, please ignore it.
243 * Don't try to do the following memory hotplug flowchart.
248 node = memory_add_physaddr_to_nid(info->start_addr);
250 result = add_memory(node, info->start_addr, info->length);
253 * If the memory block has been used by the kernel, add_memory()
254 * returns -EEXIST. If add_memory() returns the other error, it
255 * means that this memory block is not used by the kernel.
257 if (result && result != -EEXIST) {
265 * Add num_enable even if add_memory() returns -EEXIST, so the
266 * device is bound to this driver.
271 dev_err(&mem_device->device->dev, "add_memory failed\n");
272 mem_device->state = MEMORY_INVALID_STATE;
276 * Sometimes the memory device will contain several memory blocks.
277 * When one memory block is hot-added to the system memory, it will
278 * be regarded as a success.
279 * Otherwise if the last memory block can't be hot-added to the system
280 * memory, it will be failure and the memory device can't be bound with
286 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
289 struct acpi_memory_info *info, *n;
291 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
293 /* The kernel does not use this memory block */
298 * The kernel uses this memory block, but it may be not
303 result = remove_memory(info->start_addr, info->length);
307 list_del(&info->list);
314 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
316 struct acpi_memory_device *mem_device;
317 struct acpi_device *device;
318 struct acpi_eject_event *ej_event = NULL;
319 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
322 case ACPI_NOTIFY_BUS_CHECK:
323 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
324 "\nReceived BUS CHECK notification for device\n"));
326 case ACPI_NOTIFY_DEVICE_CHECK:
327 if (event == ACPI_NOTIFY_DEVICE_CHECK)
328 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
329 "\nReceived DEVICE CHECK notification for device\n"));
330 if (acpi_memory_get_device(handle, &mem_device)) {
331 acpi_handle_err(handle, "Cannot find driver data\n");
335 ost_code = ACPI_OST_SC_SUCCESS;
338 case ACPI_NOTIFY_EJECT_REQUEST:
339 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
340 "\nReceived EJECT REQUEST notification for device\n"));
342 if (acpi_bus_get_device(handle, &device)) {
343 acpi_handle_err(handle, "Device doesn't exist\n");
346 mem_device = acpi_driver_data(device);
348 acpi_handle_err(handle, "Driver Data is NULL\n");
352 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
354 pr_err(PREFIX "No memory, dropping EJECT\n");
358 ej_event->handle = handle;
359 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
360 acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
363 /* eject is performed asynchronously */
366 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
367 "Unsupported event [0x%x]\n", event));
369 /* non-hotplug event; possibly handled by other handler */
373 /* Inform firmware that the hotplug operation has completed */
374 (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
378 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
383 acpi_memory_free_device_resources(mem_device);
387 static int acpi_memory_device_add(struct acpi_device *device)
390 struct acpi_memory_device *mem_device = NULL;
396 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
400 INIT_LIST_HEAD(&mem_device->res_list);
401 mem_device->device = device;
402 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
403 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
404 device->driver_data = mem_device;
406 /* Get the range from the _CRS */
407 result = acpi_memory_get_device_resources(mem_device);
413 /* Set the device state */
414 mem_device->state = MEMORY_POWER_ON_STATE;
416 pr_debug("%s\n", acpi_device_name(device));
418 if (!acpi_memory_check_device(mem_device)) {
419 /* call add_memory func */
420 result = acpi_memory_enable_device(mem_device);
422 dev_err(&device->dev,
423 "Error in acpi_memory_enable_device\n");
424 acpi_memory_device_free(mem_device);
430 static int acpi_memory_device_remove(struct acpi_device *device, int type)
432 struct acpi_memory_device *mem_device = NULL;
435 if (!device || !acpi_driver_data(device))
438 mem_device = acpi_driver_data(device);
440 result = acpi_memory_remove_memory(mem_device);
444 acpi_memory_device_free(mem_device);
450 * Helper function to check for memory device
452 static acpi_status is_memory_device(acpi_handle handle)
456 struct acpi_device_info *info;
458 status = acpi_get_object_info(handle, &info);
459 if (ACPI_FAILURE(status))
462 if (!(info->valid & ACPI_VALID_HID)) {
467 hardware_id = info->hardware_id.string;
468 if ((hardware_id == NULL) ||
469 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
477 acpi_memory_register_notify_handler(acpi_handle handle,
478 u32 level, void *ctxt, void **retv)
483 status = is_memory_device(handle);
484 if (ACPI_FAILURE(status))
485 return AE_OK; /* continue */
487 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
488 acpi_memory_device_notify, NULL);
494 acpi_memory_deregister_notify_handler(acpi_handle handle,
495 u32 level, void *ctxt, void **retv)
500 status = is_memory_device(handle);
501 if (ACPI_FAILURE(status))
502 return AE_OK; /* continue */
504 status = acpi_remove_notify_handler(handle,
506 acpi_memory_device_notify);
508 return AE_OK; /* continue */
511 static int __init acpi_memory_device_init(void)
517 result = acpi_bus_register_driver(&acpi_memory_device_driver);
522 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
524 acpi_memory_register_notify_handler, NULL,
527 if (ACPI_FAILURE(status)) {
528 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
529 acpi_bus_unregister_driver(&acpi_memory_device_driver);
536 static void __exit acpi_memory_device_exit(void)
542 * Adding this to un-install notification handlers for all the device
545 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
547 acpi_memory_deregister_notify_handler, NULL,
550 if (ACPI_FAILURE(status))
551 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
553 acpi_bus_unregister_driver(&acpi_memory_device_driver);
558 module_init(acpi_memory_device_init);
559 module_exit(acpi_memory_device_exit);