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 firmare 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_COMPONENT 0x08000000UL
36 #define ACPI_MEMORY_DEVICE_CLASS "memory"
37 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
38 #define ACPI_MEMORY_DEVICE_DRIVER_NAME "Hotplug Mem Driver"
39 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
41 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
43 ACPI_MODULE_NAME("acpi_memory")
44 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
45 MODULE_DESCRIPTION(ACPI_MEMORY_DEVICE_DRIVER_NAME);
46 MODULE_LICENSE("GPL");
48 /* ACPI _STA method values */
49 #define ACPI_MEMORY_STA_PRESENT (0x00000001UL)
50 #define ACPI_MEMORY_STA_ENABLED (0x00000002UL)
51 #define ACPI_MEMORY_STA_FUNCTIONAL (0x00000008UL)
53 /* Memory Device States */
54 #define MEMORY_INVALID_STATE 0
55 #define MEMORY_POWER_ON_STATE 1
56 #define MEMORY_POWER_OFF_STATE 2
58 static int acpi_memory_device_add(struct acpi_device *device);
59 static int acpi_memory_device_remove(struct acpi_device *device, int type);
60 static int acpi_memory_device_start(struct acpi_device *device);
62 static struct acpi_driver acpi_memory_device_driver = {
63 .name = ACPI_MEMORY_DEVICE_DRIVER_NAME,
64 .class = ACPI_MEMORY_DEVICE_CLASS,
65 .ids = ACPI_MEMORY_DEVICE_HID,
67 .add = acpi_memory_device_add,
68 .remove = acpi_memory_device_remove,
69 .start = acpi_memory_device_start,
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 {
84 unsigned int state; /* State of the memory device */
85 struct list_head res_list;
89 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
91 struct acpi_memory_device *mem_device = context;
92 struct acpi_resource_address64 address64;
93 struct acpi_memory_info *info, *new;
96 status = acpi_resource_to_address64(resource, &address64);
97 if (ACPI_FAILURE(status) ||
98 (address64.resource_type != ACPI_MEMORY_RANGE))
101 list_for_each_entry(info, &mem_device->res_list, list) {
102 /* Can we combine the resource range information? */
103 if ((info->caching == address64.info.mem.caching) &&
104 (info->write_protect == address64.info.mem.write_protect) &&
105 (info->start_addr + info->length == address64.minimum)) {
106 info->length += address64.address_length;
111 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
115 INIT_LIST_HEAD(&new->list);
116 new->caching = address64.info.mem.caching;
117 new->write_protect = address64.info.mem.write_protect;
118 new->start_addr = address64.minimum;
119 new->length = address64.address_length;
120 list_add_tail(&new->list, &mem_device->res_list);
126 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
129 struct acpi_memory_info *info, *n;
131 ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
133 status = acpi_walk_resources(mem_device->handle, METHOD_NAME__CRS,
134 acpi_memory_get_resource, mem_device);
135 if (ACPI_FAILURE(status)) {
136 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
145 acpi_memory_get_device(acpi_handle handle,
146 struct acpi_memory_device **mem_device)
150 struct acpi_device *device = NULL;
151 struct acpi_device *pdevice = NULL;
153 ACPI_FUNCTION_TRACE("acpi_memory_get_device");
155 if (!acpi_bus_get_device(handle, &device) && device)
158 status = acpi_get_parent(handle, &phandle);
159 if (ACPI_FAILURE(status)) {
160 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
161 return_VALUE(-EINVAL);
164 /* Get the parent device */
165 status = acpi_bus_get_device(phandle, &pdevice);
166 if (ACPI_FAILURE(status)) {
167 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
168 "Error in acpi_bus_get_device\n"));
169 return_VALUE(-EINVAL);
173 * Now add the notified device. This creates the acpi_device
174 * and invokes .add function
176 status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
177 if (ACPI_FAILURE(status)) {
178 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
179 return_VALUE(-EINVAL);
183 *mem_device = acpi_driver_data(device);
184 if (!(*mem_device)) {
185 printk(KERN_ERR "\n driver data not found");
186 return_VALUE(-ENODEV);
192 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
194 unsigned long current_status;
196 ACPI_FUNCTION_TRACE("acpi_memory_check_device");
198 /* Get device present/absent information from the _STA */
199 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->handle, "_STA",
200 NULL, ¤t_status)))
201 return_VALUE(-ENODEV);
203 * Check for device status. Device should be
204 * present/enabled/functioning.
206 if (!((current_status & ACPI_MEMORY_STA_PRESENT)
207 && (current_status & ACPI_MEMORY_STA_ENABLED)
208 && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
209 return_VALUE(-ENODEV);
214 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
216 int result, num_enabled = 0;
217 struct acpi_memory_info *info;
220 ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
222 /* Get the range from the _CRS */
223 result = acpi_memory_get_device_resources(mem_device);
225 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
226 "\nget_device_resources failed\n"));
227 mem_device->state = MEMORY_INVALID_STATE;
232 * Tell the VM there is more memory here...
233 * Note: Assume that this function returns zero on success
234 * We don't have memory-hot-add rollback function,now.
235 * (i.e. memory-hot-remove function)
237 list_for_each_entry(info, &mem_device->res_list, list) {
238 u64 start_pfn, end_pfn;
240 start_pfn = info->start_addr >> PAGE_SHIFT;
241 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
243 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
244 /* already enabled. try next area */
249 result = add_memory(node, info->start_addr, info->length);
256 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
257 mem_device->state = MEMORY_INVALID_STATE;
264 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
267 struct acpi_object_list arg_list;
268 union acpi_object arg;
269 unsigned long current_status;
271 ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
273 /* Issue the _EJ0 command */
275 arg_list.pointer = &arg;
276 arg.type = ACPI_TYPE_INTEGER;
277 arg.integer.value = 1;
278 status = acpi_evaluate_object(mem_device->handle,
279 "_EJ0", &arg_list, NULL);
280 /* Return on _EJ0 failure */
281 if (ACPI_FAILURE(status)) {
282 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
283 return_VALUE(-ENODEV);
286 /* Evalute _STA to check if the device is disabled */
287 status = acpi_evaluate_integer(mem_device->handle, "_STA",
288 NULL, ¤t_status);
289 if (ACPI_FAILURE(status))
290 return_VALUE(-ENODEV);
292 /* Check for device status. Device should be disabled */
293 if (current_status & ACPI_MEMORY_STA_ENABLED)
294 return_VALUE(-EINVAL);
299 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
302 struct acpi_memory_info *info, *n;
304 ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
307 * Ask the VM to offline this memory range.
308 * Note: Assume that this function returns zero on success
310 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
312 result = remove_memory(info->start_addr, info->length);
319 /* Power-off and eject the device */
320 result = acpi_memory_powerdown_device(mem_device);
322 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
323 "Device Power Down failed.\n"));
324 /* Set the status of the device to invalid */
325 mem_device->state = MEMORY_INVALID_STATE;
329 mem_device->state = MEMORY_POWER_OFF_STATE;
333 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
335 struct acpi_memory_device *mem_device;
336 struct acpi_device *device;
338 ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
341 case ACPI_NOTIFY_BUS_CHECK:
342 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
343 "\nReceived BUS CHECK notification for device\n"));
345 case ACPI_NOTIFY_DEVICE_CHECK:
346 if (event == ACPI_NOTIFY_DEVICE_CHECK)
347 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
348 "\nReceived DEVICE CHECK notification for device\n"));
349 if (acpi_memory_get_device(handle, &mem_device)) {
350 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
351 "Error in finding driver data\n"));
355 if (!acpi_memory_check_device(mem_device)) {
356 if (acpi_memory_enable_device(mem_device))
357 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
358 "Error in acpi_memory_enable_device\n"));
361 case ACPI_NOTIFY_EJECT_REQUEST:
362 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
363 "\nReceived EJECT REQUEST notification for device\n"));
365 if (acpi_bus_get_device(handle, &device)) {
366 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
367 "Device doesn't exist\n"));
370 mem_device = acpi_driver_data(device);
372 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
373 "Driver Data is NULL\n"));
378 * Currently disabling memory device from kernel mode
379 * TBD: Can also be disabled from user mode scripts
380 * TBD: Can also be disabled by Callback registration
381 * with generic sysfs driver
383 if (acpi_memory_disable_device(mem_device))
384 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
385 "Error in acpi_memory_disable_device\n"));
387 * TBD: Invoke acpi_bus_remove to cleanup data structures
391 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
392 "Unsupported event [0x%x]\n", event));
399 static int acpi_memory_device_add(struct acpi_device *device)
402 struct acpi_memory_device *mem_device = NULL;
404 ACPI_FUNCTION_TRACE("acpi_memory_device_add");
407 return_VALUE(-EINVAL);
409 mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
411 return_VALUE(-ENOMEM);
412 memset(mem_device, 0, sizeof(struct acpi_memory_device));
414 INIT_LIST_HEAD(&mem_device->res_list);
415 mem_device->handle = device->handle;
416 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
417 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
418 acpi_driver_data(device) = mem_device;
420 /* Get the range from the _CRS */
421 result = acpi_memory_get_device_resources(mem_device);
424 return_VALUE(result);
427 /* Set the device state */
428 mem_device->state = MEMORY_POWER_ON_STATE;
430 printk(KERN_INFO "%s \n", acpi_device_name(device));
432 return_VALUE(result);
435 static int acpi_memory_device_remove(struct acpi_device *device, int type)
437 struct acpi_memory_device *mem_device = NULL;
439 ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
441 if (!device || !acpi_driver_data(device))
442 return_VALUE(-EINVAL);
444 mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
450 static int acpi_memory_device_start (struct acpi_device *device)
452 struct acpi_memory_device *mem_device;
455 ACPI_FUNCTION_TRACE("acpi_memory_device_start");
457 mem_device = acpi_driver_data(device);
459 if (!acpi_memory_check_device(mem_device)) {
460 /* call add_memory func */
461 result = acpi_memory_enable_device(mem_device);
463 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
464 "Error in acpi_memory_enable_device\n"));
466 return_VALUE(result);
470 * Helper function to check for memory device
472 static acpi_status is_memory_device(acpi_handle handle)
476 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
477 struct acpi_device_info *info;
479 ACPI_FUNCTION_TRACE("is_memory_device");
481 status = acpi_get_object_info(handle, &buffer);
482 if (ACPI_FAILURE(status))
483 return_ACPI_STATUS(AE_ERROR);
485 info = buffer.pointer;
486 if (!(info->valid & ACPI_VALID_HID)) {
487 acpi_os_free(buffer.pointer);
488 return_ACPI_STATUS(AE_ERROR);
491 hardware_id = info->hardware_id.value;
492 if ((hardware_id == NULL) ||
493 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
496 acpi_os_free(buffer.pointer);
497 return_ACPI_STATUS(status);
501 acpi_memory_register_notify_handler(acpi_handle handle,
502 u32 level, void *ctxt, void **retv)
506 ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
508 status = is_memory_device(handle);
509 if (ACPI_FAILURE(status))
510 return_ACPI_STATUS(AE_OK); /* continue */
512 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
513 acpi_memory_device_notify, NULL);
514 if (ACPI_FAILURE(status)) {
515 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
516 "Error installing notify handler\n"));
517 return_ACPI_STATUS(AE_OK); /* continue */
520 return_ACPI_STATUS(status);
524 acpi_memory_deregister_notify_handler(acpi_handle handle,
525 u32 level, void *ctxt, void **retv)
529 ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
531 status = is_memory_device(handle);
532 if (ACPI_FAILURE(status))
533 return_ACPI_STATUS(AE_OK); /* continue */
535 status = acpi_remove_notify_handler(handle,
537 acpi_memory_device_notify);
538 if (ACPI_FAILURE(status)) {
539 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
540 "Error removing notify handler\n"));
541 return_ACPI_STATUS(AE_OK); /* continue */
544 return_ACPI_STATUS(status);
547 static int __init acpi_memory_device_init(void)
552 ACPI_FUNCTION_TRACE("acpi_memory_device_init");
554 result = acpi_bus_register_driver(&acpi_memory_device_driver);
557 return_VALUE(-ENODEV);
559 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
561 acpi_memory_register_notify_handler,
564 if (ACPI_FAILURE(status)) {
565 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
566 acpi_bus_unregister_driver(&acpi_memory_device_driver);
567 return_VALUE(-ENODEV);
573 static void __exit acpi_memory_device_exit(void)
577 ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
580 * Adding this to un-install notification handlers for all the device
583 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
585 acpi_memory_deregister_notify_handler,
588 if (ACPI_FAILURE(status))
589 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
591 acpi_bus_unregister_driver(&acpi_memory_device_driver);
596 module_init(acpi_memory_device_init);
597 module_exit(acpi_memory_device_exit);