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;
230 /* Get the range from the _CRS */
231 result = acpi_memory_get_device_resources(mem_device);
233 dev_err(&mem_device->device->dev,
234 "get_device_resources failed\n");
235 mem_device->state = MEMORY_INVALID_STATE;
239 node = acpi_get_node(mem_device->device->handle);
241 * Tell the VM there is more memory here...
242 * Note: Assume that this function returns zero on success
243 * We don't have memory-hot-add rollback function,now.
244 * (i.e. memory-hot-remove function)
246 list_for_each_entry(info, &mem_device->res_list, list) {
247 if (info->enabled) { /* just sanity check...*/
252 * If the memory block size is zero, please ignore it.
253 * Don't try to do the following memory hotplug flowchart.
258 node = memory_add_physaddr_to_nid(info->start_addr);
260 result = add_memory(node, info->start_addr, info->length);
263 * If the memory block has been used by the kernel, add_memory()
264 * returns -EEXIST. If add_memory() returns the other error, it
265 * means that this memory block is not used by the kernel.
267 if (result && result != -EEXIST) {
275 * Add num_enable even if add_memory() returns -EEXIST, so the
276 * device is bound to this driver.
281 dev_err(&mem_device->device->dev, "add_memory failed\n");
282 mem_device->state = MEMORY_INVALID_STATE;
286 * Sometimes the memory device will contain several memory blocks.
287 * When one memory block is hot-added to the system memory, it will
288 * be regarded as a success.
289 * Otherwise if the last memory block can't be hot-added to the system
290 * memory, it will be failure and the memory device can't be bound with
296 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
299 struct acpi_memory_info *info, *n;
301 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
303 /* The kernel does not use this memory block */
308 * The kernel uses this memory block, but it may be not
313 result = remove_memory(info->start_addr, info->length);
317 list_del(&info->list);
324 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
326 struct acpi_memory_device *mem_device;
327 struct acpi_device *device;
328 struct acpi_eject_event *ej_event = NULL;
329 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
332 case ACPI_NOTIFY_BUS_CHECK:
333 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
334 "\nReceived BUS CHECK notification for device\n"));
336 case ACPI_NOTIFY_DEVICE_CHECK:
337 if (event == ACPI_NOTIFY_DEVICE_CHECK)
338 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
339 "\nReceived DEVICE CHECK notification for device\n"));
340 if (acpi_memory_get_device(handle, &mem_device)) {
341 acpi_handle_err(handle, "Cannot find driver data\n");
345 if (acpi_memory_check_device(mem_device))
348 if (acpi_memory_enable_device(mem_device)) {
349 acpi_handle_err(handle,"Cannot enable memory device\n");
353 ost_code = ACPI_OST_SC_SUCCESS;
356 case ACPI_NOTIFY_EJECT_REQUEST:
357 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
358 "\nReceived EJECT REQUEST notification for device\n"));
360 if (acpi_bus_get_device(handle, &device)) {
361 acpi_handle_err(handle, "Device doesn't exist\n");
364 mem_device = acpi_driver_data(device);
366 acpi_handle_err(handle, "Driver Data is NULL\n");
370 ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
372 pr_err(PREFIX "No memory, dropping EJECT\n");
376 ej_event->handle = handle;
377 ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
378 acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
381 /* eject is performed asynchronously */
384 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
385 "Unsupported event [0x%x]\n", event));
387 /* non-hotplug event; possibly handled by other handler */
391 /* Inform firmware that the hotplug operation has completed */
392 (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
396 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
401 acpi_memory_free_device_resources(mem_device);
405 static int acpi_memory_device_add(struct acpi_device *device)
408 struct acpi_memory_device *mem_device = NULL;
414 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
418 INIT_LIST_HEAD(&mem_device->res_list);
419 mem_device->device = device;
420 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
421 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
422 device->driver_data = mem_device;
424 /* Get the range from the _CRS */
425 result = acpi_memory_get_device_resources(mem_device);
431 /* Set the device state */
432 mem_device->state = MEMORY_POWER_ON_STATE;
434 pr_debug("%s\n", acpi_device_name(device));
436 if (!acpi_memory_check_device(mem_device)) {
437 /* call add_memory func */
438 result = acpi_memory_enable_device(mem_device);
440 dev_err(&device->dev,
441 "Error in acpi_memory_enable_device\n");
442 acpi_memory_device_free(mem_device);
448 static int acpi_memory_device_remove(struct acpi_device *device, int type)
450 struct acpi_memory_device *mem_device = NULL;
453 if (!device || !acpi_driver_data(device))
456 mem_device = acpi_driver_data(device);
458 result = acpi_memory_remove_memory(mem_device);
462 acpi_memory_device_free(mem_device);
468 * Helper function to check for memory device
470 static acpi_status is_memory_device(acpi_handle handle)
474 struct acpi_device_info *info;
476 status = acpi_get_object_info(handle, &info);
477 if (ACPI_FAILURE(status))
480 if (!(info->valid & ACPI_VALID_HID)) {
485 hardware_id = info->hardware_id.string;
486 if ((hardware_id == NULL) ||
487 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
495 acpi_memory_register_notify_handler(acpi_handle handle,
496 u32 level, void *ctxt, void **retv)
501 status = is_memory_device(handle);
502 if (ACPI_FAILURE(status))
503 return AE_OK; /* continue */
505 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
506 acpi_memory_device_notify, NULL);
512 acpi_memory_deregister_notify_handler(acpi_handle handle,
513 u32 level, void *ctxt, void **retv)
518 status = is_memory_device(handle);
519 if (ACPI_FAILURE(status))
520 return AE_OK; /* continue */
522 status = acpi_remove_notify_handler(handle,
524 acpi_memory_device_notify);
526 return AE_OK; /* continue */
529 static int __init acpi_memory_device_init(void)
535 result = acpi_bus_register_driver(&acpi_memory_device_driver);
540 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
542 acpi_memory_register_notify_handler, NULL,
545 if (ACPI_FAILURE(status)) {
546 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
547 acpi_bus_unregister_driver(&acpi_memory_device_driver);
554 static void __exit acpi_memory_device_exit(void)
560 * Adding this to un-install notification handlers for all the device
563 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
565 acpi_memory_deregister_notify_handler, NULL,
568 if (ACPI_FAILURE(status))
569 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
571 acpi_bus_unregister_driver(&acpi_memory_device_driver);
576 module_init(acpi_memory_device_init);
577 module_exit(acpi_memory_device_exit);