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 <acpi/acpi_drivers.h>
35 #define ACPI_MEMORY_DEVICE_CLASS "memory"
36 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
37 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
39 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
42 #define PREFIX "ACPI:memory_hp:"
44 ACPI_MODULE_NAME("acpi_memhotplug");
45 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
46 MODULE_DESCRIPTION("Hotplug Mem Driver");
47 MODULE_LICENSE("GPL");
49 /* Memory Device States */
50 #define MEMORY_INVALID_STATE 0
51 #define MEMORY_POWER_ON_STATE 1
52 #define MEMORY_POWER_OFF_STATE 2
54 static int acpi_memory_device_add(struct acpi_device *device);
55 static int acpi_memory_device_remove(struct acpi_device *device, int type);
57 static const struct acpi_device_id memory_device_ids[] = {
58 {ACPI_MEMORY_DEVICE_HID, 0},
61 MODULE_DEVICE_TABLE(acpi, memory_device_ids);
63 static struct acpi_driver acpi_memory_device_driver = {
64 .name = "acpi_memhotplug",
65 .class = ACPI_MEMORY_DEVICE_CLASS,
66 .ids = memory_device_ids,
68 .add = acpi_memory_device_add,
69 .remove = acpi_memory_device_remove,
73 struct acpi_memory_info {
74 struct list_head list;
75 u64 start_addr; /* Memory Range start physical addr */
76 u64 length; /* Memory Range length */
77 unsigned short caching; /* memory cache attribute */
78 unsigned short write_protect; /* memory read/write attribute */
79 unsigned int enabled:1;
82 struct acpi_memory_device {
83 struct acpi_device * device;
84 unsigned int state; /* State of the memory device */
85 struct list_head res_list;
88 static int acpi_hotmem_initialized;
91 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
93 struct acpi_memory_device *mem_device = context;
94 struct acpi_resource_address64 address64;
95 struct acpi_memory_info *info, *new;
98 status = acpi_resource_to_address64(resource, &address64);
99 if (ACPI_FAILURE(status) ||
100 (address64.resource_type != ACPI_MEMORY_RANGE))
103 list_for_each_entry(info, &mem_device->res_list, list) {
104 /* Can we combine the resource range information? */
105 if ((info->caching == address64.info.mem.caching) &&
106 (info->write_protect == address64.info.mem.write_protect) &&
107 (info->start_addr + info->length == address64.minimum)) {
108 info->length += address64.address_length;
113 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
117 INIT_LIST_HEAD(&new->list);
118 new->caching = address64.info.mem.caching;
119 new->write_protect = address64.info.mem.write_protect;
120 new->start_addr = address64.minimum;
121 new->length = address64.address_length;
122 list_add_tail(&new->list, &mem_device->res_list);
128 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
131 struct acpi_memory_info *info, *n;
134 if (!list_empty(&mem_device->res_list))
137 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
138 acpi_memory_get_resource, mem_device);
139 if (ACPI_FAILURE(status)) {
140 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
142 INIT_LIST_HEAD(&mem_device->res_list);
150 acpi_memory_get_device(acpi_handle handle,
151 struct acpi_memory_device **mem_device)
155 struct acpi_device *device = NULL;
156 struct acpi_device *pdevice = NULL;
160 if (!acpi_bus_get_device(handle, &device) && device)
163 status = acpi_get_parent(handle, &phandle);
164 if (ACPI_FAILURE(status)) {
165 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
169 /* Get the parent device */
170 result = acpi_bus_get_device(phandle, &pdevice);
172 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
177 * Now add the notified device. This creates the acpi_device
178 * and invokes .add function
180 result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
182 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
187 *mem_device = acpi_driver_data(device);
188 if (!(*mem_device)) {
189 printk(KERN_ERR "\n driver data not found");
196 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
198 unsigned long long current_status;
200 /* Get device present/absent information from the _STA */
201 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
202 NULL, ¤t_status)))
205 * Check for device status. Device should be
206 * present/enabled/functioning.
208 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
209 && (current_status & ACPI_STA_DEVICE_ENABLED)
210 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
216 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
218 int result, num_enabled = 0;
219 struct acpi_memory_info *info;
223 /* Get the range from the _CRS */
224 result = acpi_memory_get_device_resources(mem_device);
226 printk(KERN_ERR PREFIX "get_device_resources failed\n");
227 mem_device->state = MEMORY_INVALID_STATE;
231 node = acpi_get_node(mem_device->device->handle);
233 * Tell the VM there is more memory here...
234 * Note: Assume that this function returns zero on success
235 * We don't have memory-hot-add rollback function,now.
236 * (i.e. memory-hot-remove function)
238 list_for_each_entry(info, &mem_device->res_list, list) {
239 if (info->enabled) { /* just sanity check...*/
244 * If the memory block size is zero, please ignore it.
245 * Don't try to do the following memory hotplug flowchart.
250 node = memory_add_physaddr_to_nid(info->start_addr);
252 result = add_memory(node, info->start_addr, info->length);
259 printk(KERN_ERR PREFIX "add_memory failed\n");
260 mem_device->state = MEMORY_INVALID_STATE;
264 * Sometimes the memory device will contain several memory blocks.
265 * When one memory block is hot-added to the system memory, it will
266 * be regarded as a success.
267 * Otherwise if the last memory block can't be hot-added to the system
268 * memory, it will be failure and the memory device can't be bound with
274 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
277 struct acpi_object_list arg_list;
278 union acpi_object arg;
279 unsigned long long current_status;
282 /* Issue the _EJ0 command */
284 arg_list.pointer = &arg;
285 arg.type = ACPI_TYPE_INTEGER;
286 arg.integer.value = 1;
287 status = acpi_evaluate_object(mem_device->device->handle,
288 "_EJ0", &arg_list, NULL);
289 /* Return on _EJ0 failure */
290 if (ACPI_FAILURE(status)) {
291 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
295 /* Evalute _STA to check if the device is disabled */
296 status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
297 NULL, ¤t_status);
298 if (ACPI_FAILURE(status))
301 /* Check for device status. Device should be disabled */
302 if (current_status & ACPI_STA_DEVICE_ENABLED)
308 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
311 struct acpi_memory_info *info, *n;
315 * Ask the VM to offline this memory range.
316 * Note: Assume that this function returns zero on success
318 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
320 result = remove_memory(info->start_addr, info->length);
327 /* Power-off and eject the device */
328 result = acpi_memory_powerdown_device(mem_device);
330 /* Set the status of the device to invalid */
331 mem_device->state = MEMORY_INVALID_STATE;
335 mem_device->state = MEMORY_POWER_OFF_STATE;
339 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
341 struct acpi_memory_device *mem_device;
342 struct acpi_device *device;
346 case ACPI_NOTIFY_BUS_CHECK:
347 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
348 "\nReceived BUS CHECK notification for device\n"));
350 case ACPI_NOTIFY_DEVICE_CHECK:
351 if (event == ACPI_NOTIFY_DEVICE_CHECK)
352 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
353 "\nReceived DEVICE CHECK notification for device\n"));
354 if (acpi_memory_get_device(handle, &mem_device)) {
355 printk(KERN_ERR PREFIX "Cannot find driver data\n");
359 if (!acpi_memory_check_device(mem_device)) {
360 if (acpi_memory_enable_device(mem_device))
361 printk(KERN_ERR PREFIX
362 "Cannot enable memory device\n");
365 case ACPI_NOTIFY_EJECT_REQUEST:
366 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
367 "\nReceived EJECT REQUEST notification for device\n"));
369 if (acpi_bus_get_device(handle, &device)) {
370 printk(KERN_ERR PREFIX "Device doesn't exist\n");
373 mem_device = acpi_driver_data(device);
375 printk(KERN_ERR PREFIX "Driver Data is NULL\n");
380 * Currently disabling memory device from kernel mode
381 * TBD: Can also be disabled from user mode scripts
382 * TBD: Can also be disabled by Callback registration
383 * with generic sysfs driver
385 if (acpi_memory_disable_device(mem_device))
386 printk(KERN_ERR PREFIX
387 "Disable memory device\n");
389 * TBD: Invoke acpi_bus_remove to cleanup data structures
393 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
394 "Unsupported event [0x%x]\n", event));
401 static int acpi_memory_device_add(struct acpi_device *device)
404 struct acpi_memory_device *mem_device = NULL;
410 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
414 INIT_LIST_HEAD(&mem_device->res_list);
415 mem_device->device = device;
416 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
417 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
418 device->driver_data = mem_device;
420 /* Get the range from the _CRS */
421 result = acpi_memory_get_device_resources(mem_device);
427 /* Set the device state */
428 mem_device->state = MEMORY_POWER_ON_STATE;
430 printk(KERN_DEBUG "%s \n", acpi_device_name(device));
433 * Early boot code has recognized memory area by EFI/E820.
434 * If DSDT shows these memory devices on boot, hotplug is not necessary
435 * for them. So, it just returns until completion of this driver's
438 if (!acpi_hotmem_initialized)
441 if (!acpi_memory_check_device(mem_device)) {
442 /* call add_memory func */
443 result = acpi_memory_enable_device(mem_device);
445 printk(KERN_ERR PREFIX
446 "Error in acpi_memory_enable_device\n");
451 static int acpi_memory_device_remove(struct acpi_device *device, int type)
453 struct acpi_memory_device *mem_device = NULL;
456 if (!device || !acpi_driver_data(device))
459 mem_device = acpi_driver_data(device);
466 * Helper function to check for memory device
468 static acpi_status is_memory_device(acpi_handle handle)
472 struct acpi_device_info *info;
474 status = acpi_get_object_info(handle, &info);
475 if (ACPI_FAILURE(status))
478 if (!(info->valid & ACPI_VALID_HID)) {
483 hardware_id = info->hardware_id.string;
484 if ((hardware_id == NULL) ||
485 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
493 acpi_memory_register_notify_handler(acpi_handle handle,
494 u32 level, void *ctxt, void **retv)
499 status = is_memory_device(handle);
500 if (ACPI_FAILURE(status))
501 return AE_OK; /* continue */
503 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
504 acpi_memory_device_notify, NULL);
510 acpi_memory_deregister_notify_handler(acpi_handle handle,
511 u32 level, void *ctxt, void **retv)
516 status = is_memory_device(handle);
517 if (ACPI_FAILURE(status))
518 return AE_OK; /* continue */
520 status = acpi_remove_notify_handler(handle,
522 acpi_memory_device_notify);
524 return AE_OK; /* continue */
527 static int __init acpi_memory_device_init(void)
533 result = acpi_bus_register_driver(&acpi_memory_device_driver);
538 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
540 acpi_memory_register_notify_handler, NULL,
543 if (ACPI_FAILURE(status)) {
544 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
545 acpi_bus_unregister_driver(&acpi_memory_device_driver);
549 acpi_hotmem_initialized = 1;
553 static void __exit acpi_memory_device_exit(void)
559 * Adding this to un-install notification handlers for all the device
562 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
564 acpi_memory_deregister_notify_handler, NULL,
567 if (ACPI_FAILURE(status))
568 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
570 acpi_bus_unregister_driver(&acpi_memory_device_driver);
575 module_init(acpi_memory_device_init);
576 module_exit(acpi_memory_device_exit);