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_get_device_resources(struct acpi_memory_device *mem_device)
132 struct acpi_memory_info *info, *n;
135 if (!list_empty(&mem_device->res_list))
138 status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
139 acpi_memory_get_resource, mem_device);
140 if (ACPI_FAILURE(status)) {
141 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
143 INIT_LIST_HEAD(&mem_device->res_list);
151 acpi_memory_get_device(acpi_handle handle,
152 struct acpi_memory_device **mem_device)
156 struct acpi_device *device = NULL;
157 struct acpi_device *pdevice = NULL;
161 if (!acpi_bus_get_device(handle, &device) && device)
164 status = acpi_get_parent(handle, &phandle);
165 if (ACPI_FAILURE(status)) {
166 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
170 /* Get the parent device */
171 result = acpi_bus_get_device(phandle, &pdevice);
173 printk(KERN_WARNING PREFIX "Cannot get acpi bus device");
178 * Now add the notified device. This creates the acpi_device
179 * and invokes .add function
181 result = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
183 printk(KERN_WARNING PREFIX "Cannot add acpi bus");
188 *mem_device = acpi_driver_data(device);
189 if (!(*mem_device)) {
190 printk(KERN_ERR "\n driver data not found");
197 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
199 unsigned long long current_status;
201 /* Get device present/absent information from the _STA */
202 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
203 NULL, ¤t_status)))
206 * Check for device status. Device should be
207 * present/enabled/functioning.
209 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
210 && (current_status & ACPI_STA_DEVICE_ENABLED)
211 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
217 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
219 int result, num_enabled = 0;
220 struct acpi_memory_info *info;
224 /* Get the range from the _CRS */
225 result = acpi_memory_get_device_resources(mem_device);
227 printk(KERN_ERR PREFIX "get_device_resources failed\n");
228 mem_device->state = MEMORY_INVALID_STATE;
232 node = acpi_get_node(mem_device->device->handle);
234 * Tell the VM there is more memory here...
235 * Note: Assume that this function returns zero on success
236 * We don't have memory-hot-add rollback function,now.
237 * (i.e. memory-hot-remove function)
239 list_for_each_entry(info, &mem_device->res_list, list) {
240 if (info->enabled) { /* just sanity check...*/
245 * If the memory block size is zero, please ignore it.
246 * Don't try to do the following memory hotplug flowchart.
251 node = memory_add_physaddr_to_nid(info->start_addr);
253 result = add_memory(node, info->start_addr, info->length);
260 printk(KERN_ERR PREFIX "add_memory failed\n");
261 mem_device->state = MEMORY_INVALID_STATE;
265 * Sometimes the memory device will contain several memory blocks.
266 * When one memory block is hot-added to the system memory, it will
267 * be regarded as a success.
268 * Otherwise if the last memory block can't be hot-added to the system
269 * memory, it will be failure and the memory device can't be bound with
275 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
278 struct acpi_object_list arg_list;
279 union acpi_object arg;
280 unsigned long long current_status;
283 /* Issue the _EJ0 command */
285 arg_list.pointer = &arg;
286 arg.type = ACPI_TYPE_INTEGER;
287 arg.integer.value = 1;
288 status = acpi_evaluate_object(mem_device->device->handle,
289 "_EJ0", &arg_list, NULL);
290 /* Return on _EJ0 failure */
291 if (ACPI_FAILURE(status)) {
292 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
296 /* Evalute _STA to check if the device is disabled */
297 status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
298 NULL, ¤t_status);
299 if (ACPI_FAILURE(status))
302 /* Check for device status. Device should be disabled */
303 if (current_status & ACPI_STA_DEVICE_ENABLED)
309 static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
312 struct acpi_memory_info *info, *n;
314 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
316 result = remove_memory(info->start_addr, info->length);
321 list_del(&info->list);
328 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
333 * Ask the VM to offline this memory range.
334 * Note: Assume that this function returns zero on success
336 result = acpi_memory_remove_memory(mem_device);
340 /* Power-off and eject the device */
341 result = acpi_memory_powerdown_device(mem_device);
343 /* Set the status of the device to invalid */
344 mem_device->state = MEMORY_INVALID_STATE;
348 mem_device->state = MEMORY_POWER_OFF_STATE;
352 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
354 struct acpi_memory_device *mem_device;
355 struct acpi_device *device;
356 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
359 case ACPI_NOTIFY_BUS_CHECK:
360 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
361 "\nReceived BUS CHECK notification for device\n"));
363 case ACPI_NOTIFY_DEVICE_CHECK:
364 if (event == ACPI_NOTIFY_DEVICE_CHECK)
365 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
366 "\nReceived DEVICE CHECK notification for device\n"));
367 if (acpi_memory_get_device(handle, &mem_device)) {
368 printk(KERN_ERR PREFIX "Cannot find driver data\n");
372 if (acpi_memory_check_device(mem_device))
375 if (acpi_memory_enable_device(mem_device)) {
376 printk(KERN_ERR PREFIX "Cannot enable memory device\n");
380 ost_code = ACPI_OST_SC_SUCCESS;
383 case ACPI_NOTIFY_EJECT_REQUEST:
384 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
385 "\nReceived EJECT REQUEST notification for device\n"));
387 if (acpi_bus_get_device(handle, &device)) {
388 printk(KERN_ERR PREFIX "Device doesn't exist\n");
391 mem_device = acpi_driver_data(device);
393 printk(KERN_ERR PREFIX "Driver Data is NULL\n");
398 * Currently disabling memory device from kernel mode
399 * TBD: Can also be disabled from user mode scripts
400 * TBD: Can also be disabled by Callback registration
401 * with generic sysfs driver
403 if (acpi_memory_disable_device(mem_device)) {
404 printk(KERN_ERR PREFIX "Disable memory device\n");
406 * If _EJ0 was called but failed, _OST is not
409 if (mem_device->state == MEMORY_INVALID_STATE)
416 * Invoke acpi_bus_trim() to remove memory device
418 acpi_bus_trim(device, 1);
420 /* _EJ0 succeeded; _OST is not necessary */
424 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
425 "Unsupported event [0x%x]\n", event));
427 /* non-hotplug event; possibly handled by other handler */
431 /* Inform firmware that the hotplug operation has completed */
432 (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
436 static int acpi_memory_device_add(struct acpi_device *device)
439 struct acpi_memory_device *mem_device = NULL;
445 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
449 INIT_LIST_HEAD(&mem_device->res_list);
450 mem_device->device = device;
451 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
452 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
453 device->driver_data = mem_device;
455 /* Get the range from the _CRS */
456 result = acpi_memory_get_device_resources(mem_device);
462 /* Set the device state */
463 mem_device->state = MEMORY_POWER_ON_STATE;
465 printk(KERN_DEBUG "%s \n", acpi_device_name(device));
468 * Early boot code has recognized memory area by EFI/E820.
469 * If DSDT shows these memory devices on boot, hotplug is not necessary
470 * for them. So, it just returns until completion of this driver's
473 if (!acpi_hotmem_initialized)
476 if (!acpi_memory_check_device(mem_device)) {
477 /* call add_memory func */
478 result = acpi_memory_enable_device(mem_device);
480 printk(KERN_ERR PREFIX
481 "Error in acpi_memory_enable_device\n");
486 static int acpi_memory_device_remove(struct acpi_device *device, int type)
488 struct acpi_memory_device *mem_device = NULL;
491 if (!device || !acpi_driver_data(device))
494 mem_device = acpi_driver_data(device);
496 result = acpi_memory_remove_memory(mem_device);
506 * Helper function to check for memory device
508 static acpi_status is_memory_device(acpi_handle handle)
512 struct acpi_device_info *info;
514 status = acpi_get_object_info(handle, &info);
515 if (ACPI_FAILURE(status))
518 if (!(info->valid & ACPI_VALID_HID)) {
523 hardware_id = info->hardware_id.string;
524 if ((hardware_id == NULL) ||
525 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
533 acpi_memory_register_notify_handler(acpi_handle handle,
534 u32 level, void *ctxt, void **retv)
539 status = is_memory_device(handle);
540 if (ACPI_FAILURE(status))
541 return AE_OK; /* continue */
543 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
544 acpi_memory_device_notify, NULL);
550 acpi_memory_deregister_notify_handler(acpi_handle handle,
551 u32 level, void *ctxt, void **retv)
556 status = is_memory_device(handle);
557 if (ACPI_FAILURE(status))
558 return AE_OK; /* continue */
560 status = acpi_remove_notify_handler(handle,
562 acpi_memory_device_notify);
564 return AE_OK; /* continue */
567 static int __init acpi_memory_device_init(void)
573 result = acpi_bus_register_driver(&acpi_memory_device_driver);
578 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
580 acpi_memory_register_notify_handler, NULL,
583 if (ACPI_FAILURE(status)) {
584 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
585 acpi_bus_unregister_driver(&acpi_memory_device_driver);
589 acpi_hotmem_initialized = 1;
593 static void __exit acpi_memory_device_exit(void)
599 * Adding this to un-install notification handlers for all the device
602 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
604 acpi_memory_deregister_notify_handler, NULL,
607 if (ACPI_FAILURE(status))
608 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
610 acpi_bus_unregister_driver(&acpi_memory_device_driver);
615 module_init(acpi_memory_device_init);
616 module_exit(acpi_memory_device_exit);