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;
219 ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
221 /* Get the range from the _CRS */
222 result = acpi_memory_get_device_resources(mem_device);
224 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
225 "\nget_device_resources failed\n"));
226 mem_device->state = MEMORY_INVALID_STATE;
231 * Tell the VM there is more memory here...
232 * Note: Assume that this function returns zero on success
233 * We don't have memory-hot-add rollback function,now.
234 * (i.e. memory-hot-remove function)
236 list_for_each_entry(info, &mem_device->res_list, list) {
237 u64 start_pfn, end_pfn;
239 start_pfn = info->start_addr >> PAGE_SHIFT;
240 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
242 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
243 /* already enabled. try next area */
248 result = add_memory(info->start_addr, info->length);
255 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
256 mem_device->state = MEMORY_INVALID_STATE;
263 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
266 struct acpi_object_list arg_list;
267 union acpi_object arg;
268 unsigned long current_status;
270 ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
272 /* Issue the _EJ0 command */
274 arg_list.pointer = &arg;
275 arg.type = ACPI_TYPE_INTEGER;
276 arg.integer.value = 1;
277 status = acpi_evaluate_object(mem_device->handle,
278 "_EJ0", &arg_list, NULL);
279 /* Return on _EJ0 failure */
280 if (ACPI_FAILURE(status)) {
281 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_EJ0 failed.\n"));
282 return_VALUE(-ENODEV);
285 /* Evalute _STA to check if the device is disabled */
286 status = acpi_evaluate_integer(mem_device->handle, "_STA",
287 NULL, ¤t_status);
288 if (ACPI_FAILURE(status))
289 return_VALUE(-ENODEV);
291 /* Check for device status. Device should be disabled */
292 if (current_status & ACPI_MEMORY_STA_ENABLED)
293 return_VALUE(-EINVAL);
298 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
301 struct acpi_memory_info *info, *n;
303 ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
306 * Ask the VM to offline this memory range.
307 * Note: Assume that this function returns zero on success
309 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
311 result = remove_memory(info->start_addr, info->length);
318 /* Power-off and eject the device */
319 result = acpi_memory_powerdown_device(mem_device);
321 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
322 "Device Power Down failed.\n"));
323 /* Set the status of the device to invalid */
324 mem_device->state = MEMORY_INVALID_STATE;
328 mem_device->state = MEMORY_POWER_OFF_STATE;
332 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
334 struct acpi_memory_device *mem_device;
335 struct acpi_device *device;
337 ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
340 case ACPI_NOTIFY_BUS_CHECK:
341 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
342 "\nReceived BUS CHECK notification for device\n"));
344 case ACPI_NOTIFY_DEVICE_CHECK:
345 if (event == ACPI_NOTIFY_DEVICE_CHECK)
346 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
347 "\nReceived DEVICE CHECK notification for device\n"));
348 if (acpi_memory_get_device(handle, &mem_device)) {
349 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
350 "Error in finding driver data\n"));
354 if (!acpi_memory_check_device(mem_device)) {
355 if (acpi_memory_enable_device(mem_device))
356 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
357 "Error in acpi_memory_enable_device\n"));
360 case ACPI_NOTIFY_EJECT_REQUEST:
361 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
362 "\nReceived EJECT REQUEST notification for device\n"));
364 if (acpi_bus_get_device(handle, &device)) {
365 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
366 "Device doesn't exist\n"));
369 mem_device = acpi_driver_data(device);
371 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
372 "Driver Data is NULL\n"));
377 * Currently disabling memory device from kernel mode
378 * TBD: Can also be disabled from user mode scripts
379 * TBD: Can also be disabled by Callback registration
380 * with generic sysfs driver
382 if (acpi_memory_disable_device(mem_device))
383 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
384 "Error in acpi_memory_disable_device\n"));
386 * TBD: Invoke acpi_bus_remove to cleanup data structures
390 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
391 "Unsupported event [0x%x]\n", event));
398 static int acpi_memory_device_add(struct acpi_device *device)
401 struct acpi_memory_device *mem_device = NULL;
403 ACPI_FUNCTION_TRACE("acpi_memory_device_add");
406 return_VALUE(-EINVAL);
408 mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
410 return_VALUE(-ENOMEM);
411 memset(mem_device, 0, sizeof(struct acpi_memory_device));
413 INIT_LIST_HEAD(&mem_device->res_list);
414 mem_device->handle = device->handle;
415 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
416 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
417 acpi_driver_data(device) = mem_device;
419 /* Get the range from the _CRS */
420 result = acpi_memory_get_device_resources(mem_device);
423 return_VALUE(result);
426 /* Set the device state */
427 mem_device->state = MEMORY_POWER_ON_STATE;
429 printk(KERN_INFO "%s \n", acpi_device_name(device));
431 return_VALUE(result);
434 static int acpi_memory_device_remove(struct acpi_device *device, int type)
436 struct acpi_memory_device *mem_device = NULL;
438 ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
440 if (!device || !acpi_driver_data(device))
441 return_VALUE(-EINVAL);
443 mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
449 static int acpi_memory_device_start (struct acpi_device *device)
451 struct acpi_memory_device *mem_device;
454 ACPI_FUNCTION_TRACE("acpi_memory_device_start");
456 mem_device = acpi_driver_data(device);
458 if (!acpi_memory_check_device(mem_device)) {
459 /* call add_memory func */
460 result = acpi_memory_enable_device(mem_device);
462 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
463 "Error in acpi_memory_enable_device\n"));
465 return_VALUE(result);
469 * Helper function to check for memory device
471 static acpi_status is_memory_device(acpi_handle handle)
475 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
476 struct acpi_device_info *info;
478 ACPI_FUNCTION_TRACE("is_memory_device");
480 status = acpi_get_object_info(handle, &buffer);
481 if (ACPI_FAILURE(status))
482 return_ACPI_STATUS(AE_ERROR);
484 info = buffer.pointer;
485 if (!(info->valid & ACPI_VALID_HID)) {
486 acpi_os_free(buffer.pointer);
487 return_ACPI_STATUS(AE_ERROR);
490 hardware_id = info->hardware_id.value;
491 if ((hardware_id == NULL) ||
492 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
495 acpi_os_free(buffer.pointer);
496 return_ACPI_STATUS(status);
500 acpi_memory_register_notify_handler(acpi_handle handle,
501 u32 level, void *ctxt, void **retv)
505 ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
507 status = is_memory_device(handle);
508 if (ACPI_FAILURE(status))
509 return_ACPI_STATUS(AE_OK); /* continue */
511 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
512 acpi_memory_device_notify, NULL);
513 if (ACPI_FAILURE(status)) {
514 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
515 "Error installing notify handler\n"));
516 return_ACPI_STATUS(AE_OK); /* continue */
519 return_ACPI_STATUS(status);
523 acpi_memory_deregister_notify_handler(acpi_handle handle,
524 u32 level, void *ctxt, void **retv)
528 ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
530 status = is_memory_device(handle);
531 if (ACPI_FAILURE(status))
532 return_ACPI_STATUS(AE_OK); /* continue */
534 status = acpi_remove_notify_handler(handle,
536 acpi_memory_device_notify);
537 if (ACPI_FAILURE(status)) {
538 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
539 "Error removing notify handler\n"));
540 return_ACPI_STATUS(AE_OK); /* continue */
543 return_ACPI_STATUS(status);
546 static int __init acpi_memory_device_init(void)
551 ACPI_FUNCTION_TRACE("acpi_memory_device_init");
553 result = acpi_bus_register_driver(&acpi_memory_device_driver);
556 return_VALUE(-ENODEV);
558 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
560 acpi_memory_register_notify_handler,
563 if (ACPI_FAILURE(status)) {
564 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
565 acpi_bus_unregister_driver(&acpi_memory_device_driver);
566 return_VALUE(-ENODEV);
572 static void __exit acpi_memory_device_exit(void)
576 ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
579 * Adding this to un-install notification handlers for all the device
582 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
584 acpi_memory_deregister_notify_handler,
587 if (ACPI_FAILURE(status))
588 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "walk_namespace failed\n"));
590 acpi_bus_unregister_driver(&acpi_memory_device_driver);
595 module_init(acpi_memory_device_init);
596 module_exit(acpi_memory_device_exit);