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 <acpi/acpi_drivers.h>
36 #define ACPI_MEMORY_DEVICE_CLASS "memory"
37 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
38 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
40 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
43 #define PREFIX "ACPI:memory_hp:"
45 ACPI_MODULE_NAME("acpi_memhotplug");
46 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
47 MODULE_DESCRIPTION("Hotplug Mem Driver");
48 MODULE_LICENSE("GPL");
50 /* Memory Device States */
51 #define MEMORY_INVALID_STATE 0
52 #define MEMORY_POWER_ON_STATE 1
53 #define MEMORY_POWER_OFF_STATE 2
55 static int acpi_memory_device_add(struct acpi_device *device);
56 static int acpi_memory_device_remove(struct acpi_device *device, int type);
58 static const struct acpi_device_id memory_device_ids[] = {
59 {ACPI_MEMORY_DEVICE_HID, 0},
62 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
64 static struct acpi_driver acpi_memory_device_driver = {
65 .name = "acpi_memhotplug",
66 .class = ACPI_MEMORY_DEVICE_CLASS,
67 .ids = memory_device_ids,
69 .add = acpi_memory_device_add,
70 .remove = acpi_memory_device_remove,
74 struct acpi_memory_info {
75 struct list_head list;
76 u64 start_addr; /* Memory Range start physical addr */
77 u64 length; /* Memory Range length */
78 unsigned short caching; /* memory cache attribute */
79 unsigned short write_protect; /* memory read/write attribute */
80 unsigned int enabled:1;
83 struct acpi_memory_device {
84 struct acpi_device * device;
85 unsigned int state; /* State of the memory device */
86 struct list_head res_list;
89 static int acpi_hotmem_initialized;
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 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
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 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
194 *mem_device = acpi_driver_data(device);
195 if (!(*mem_device)) {
196 printk(KERN_ERR "\n driver data not found");
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 printk(KERN_ERR PREFIX "get_device_resources failed\n");
234 mem_device->state = MEMORY_INVALID_STATE;
238 node = acpi_get_node(mem_device->device->handle);
240 * Tell the VM there is more memory here...
241 * Note: Assume that this function returns zero on success
242 * We don't have memory-hot-add rollback function,now.
243 * (i.e. memory-hot-remove function)
245 list_for_each_entry(info, &mem_device->res_list, list) {
246 if (info->enabled) { /* just sanity check...*/
251 * If the memory block size is zero, please ignore it.
252 * Don't try to do the following memory hotplug flowchart.
257 node = memory_add_physaddr_to_nid(info->start_addr);
259 result = add_memory(node, info->start_addr, info->length);
266 printk(KERN_ERR PREFIX "add_memory failed\n");
267 mem_device->state = MEMORY_INVALID_STATE;
271 * Sometimes the memory device will contain several memory blocks.
272 * When one memory block is hot-added to the system memory, it will
273 * be regarded as a success.
274 * Otherwise if the last memory block can't be hot-added to the system
275 * memory, it will be failure and the memory device can't be bound with
281 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
284 struct acpi_object_list arg_list;
285 union acpi_object arg;
286 unsigned long long current_status;
289 /* Issue the _EJ0 command */
291 arg_list.pointer = &arg;
292 arg.type = ACPI_TYPE_INTEGER;
293 arg.integer.value = 1;
294 status = acpi_evaluate_object(mem_device->device->handle,
295 "_EJ0", &arg_list, NULL);
296 /* Return on _EJ0 failure */
297 if (ACPI_FAILURE(status)) {
298 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
302 /* Evalute _STA to check if the device is disabled */
303 status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
304 NULL, ¤t_status);
305 if (ACPI_FAILURE(status))
308 /* Check for device status. Device should be disabled */
309 if (current_status & ACPI_STA_DEVICE_ENABLED)
315 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
318 struct acpi_memory_info *info, *n;
322 * Ask the VM to offline this memory range.
323 * Note: Assume that this function returns zero on success
325 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
327 result = remove_memory(info->start_addr, info->length);
334 /* Power-off and eject the device */
335 result = acpi_memory_powerdown_device(mem_device);
337 /* Set the status of the device to invalid */
338 mem_device->state = MEMORY_INVALID_STATE;
342 mem_device->state = MEMORY_POWER_OFF_STATE;
346 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
348 struct acpi_memory_device *mem_device;
349 struct acpi_device *device;
350 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
353 case ACPI_NOTIFY_BUS_CHECK:
354 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
355 "\nReceived BUS CHECK notification for device\n"));
357 case ACPI_NOTIFY_DEVICE_CHECK:
358 if (event == ACPI_NOTIFY_DEVICE_CHECK)
359 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
360 "\nReceived DEVICE CHECK notification for device\n"));
361 if (acpi_memory_get_device(handle, &mem_device)) {
362 printk(KERN_ERR PREFIX "Cannot find driver data\n");
366 if (acpi_memory_check_device(mem_device))
369 if (acpi_memory_enable_device(mem_device)) {
370 printk(KERN_ERR PREFIX "Cannot enable memory device\n");
374 ost_code = ACPI_OST_SC_SUCCESS;
377 case ACPI_NOTIFY_EJECT_REQUEST:
378 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
379 "\nReceived EJECT REQUEST notification for device\n"));
381 if (acpi_bus_get_device(handle, &device)) {
382 printk(KERN_ERR PREFIX "Device doesn't exist\n");
385 mem_device = acpi_driver_data(device);
387 printk(KERN_ERR PREFIX "Driver Data is NULL\n");
392 * Currently disabling memory device from kernel mode
393 * TBD: Can also be disabled from user mode scripts
394 * TBD: Can also be disabled by Callback registration
395 * with generic sysfs driver
397 if (acpi_memory_disable_device(mem_device)) {
398 printk(KERN_ERR PREFIX "Disable memory device\n");
400 * If _EJ0 was called but failed, _OST is not
403 if (mem_device->state == MEMORY_INVALID_STATE)
410 * TBD: Invoke acpi_bus_remove to cleanup data structures
413 /* _EJ0 succeeded; _OST is not necessary */
417 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
418 "Unsupported event [0x%x]\n", event));
420 /* non-hotplug event; possibly handled by other handler */
424 /* Inform firmware that the hotplug operation has completed */
425 (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
429 static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
434 acpi_memory_free_device_resources(mem_device);
438 static int acpi_memory_device_add(struct acpi_device *device)
441 struct acpi_memory_device *mem_device = NULL;
447 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
451 INIT_LIST_HEAD(&mem_device->res_list);
452 mem_device->device = device;
453 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
454 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
455 device->driver_data = mem_device;
457 /* Get the range from the _CRS */
458 result = acpi_memory_get_device_resources(mem_device);
464 /* Set the device state */
465 mem_device->state = MEMORY_POWER_ON_STATE;
467 printk(KERN_DEBUG "%s \n", acpi_device_name(device));
470 * Early boot code has recognized memory area by EFI/E820.
471 * If DSDT shows these memory devices on boot, hotplug is not necessary
472 * for them. So, it just returns until completion of this driver's
475 if (!acpi_hotmem_initialized)
478 if (!acpi_memory_check_device(mem_device)) {
479 /* call add_memory func */
480 result = acpi_memory_enable_device(mem_device);
482 printk(KERN_ERR PREFIX
483 "Error in acpi_memory_enable_device\n");
488 static int acpi_memory_device_remove(struct acpi_device *device, int type)
490 if (!device || !acpi_driver_data(device))
493 acpi_memory_device_free(acpi_driver_data(device));
499 * Helper function to check for memory device
501 static acpi_status is_memory_device(acpi_handle handle)
505 struct acpi_device_info *info;
507 status = acpi_get_object_info(handle, &info);
508 if (ACPI_FAILURE(status))
511 if (!(info->valid & ACPI_VALID_HID)) {
516 hardware_id = info->hardware_id.string;
517 if ((hardware_id == NULL) ||
518 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
526 acpi_memory_register_notify_handler(acpi_handle handle,
527 u32 level, void *ctxt, void **retv)
532 status = is_memory_device(handle);
533 if (ACPI_FAILURE(status))
534 return AE_OK; /* continue */
536 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
537 acpi_memory_device_notify, NULL);
543 acpi_memory_deregister_notify_handler(acpi_handle handle,
544 u32 level, void *ctxt, void **retv)
549 status = is_memory_device(handle);
550 if (ACPI_FAILURE(status))
551 return AE_OK; /* continue */
553 status = acpi_remove_notify_handler(handle,
555 acpi_memory_device_notify);
557 return AE_OK; /* continue */
560 static int __init acpi_memory_device_init(void)
566 result = acpi_bus_register_driver(&acpi_memory_device_driver);
571 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
573 acpi_memory_register_notify_handler, NULL,
576 if (ACPI_FAILURE(status)) {
577 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
578 acpi_bus_unregister_driver(&acpi_memory_device_driver);
582 acpi_hotmem_initialized = 1;
586 static void __exit acpi_memory_device_exit(void)
592 * Adding this to un-install notification handlers for all the device
595 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
597 acpi_memory_deregister_notify_handler, NULL,
600 if (ACPI_FAILURE(status))
601 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
603 acpi_bus_unregister_driver(&acpi_memory_device_driver);
608 module_init(acpi_memory_device_init);
609 module_exit(acpi_memory_device_exit);