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 struct acpi_device * device;
85 unsigned int state; /* State of the memory device */
86 struct list_head res_list;
90 acpi_memory_get_resource(struct acpi_resource *resource, void *context)
92 struct acpi_memory_device *mem_device = context;
93 struct acpi_resource_address64 address64;
94 struct acpi_memory_info *info, *new;
97 status = acpi_resource_to_address64(resource, &address64);
98 if (ACPI_FAILURE(status) ||
99 (address64.resource_type != ACPI_MEMORY_RANGE))
102 list_for_each_entry(info, &mem_device->res_list, list) {
103 /* Can we combine the resource range information? */
104 if ((info->caching == address64.info.mem.caching) &&
105 (info->write_protect == address64.info.mem.write_protect) &&
106 (info->start_addr + info->length == address64.minimum)) {
107 info->length += address64.address_length;
112 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
116 INIT_LIST_HEAD(&new->list);
117 new->caching = address64.info.mem.caching;
118 new->write_protect = address64.info.mem.write_protect;
119 new->start_addr = address64.minimum;
120 new->length = address64.address_length;
121 list_add_tail(&new->list, &mem_device->res_list);
127 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
130 struct acpi_memory_info *info, *n;
133 status = acpi_walk_resources(mem_device->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;
154 if (!acpi_bus_get_device(handle, &device) && device)
157 status = acpi_get_parent(handle, &phandle);
158 if (ACPI_FAILURE(status)) {
159 ACPI_EXCEPTION((AE_INFO, status, "Cannot find acpi parent"));
163 /* Get the parent device */
164 status = acpi_bus_get_device(phandle, &pdevice);
165 if (ACPI_FAILURE(status)) {
166 ACPI_EXCEPTION((AE_INFO, status, "Cannot get acpi bus device"));
171 * Now add the notified device. This creates the acpi_device
172 * and invokes .add function
174 status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
175 if (ACPI_FAILURE(status)) {
176 ACPI_EXCEPTION((AE_INFO, status, "Cannot add acpi bus"));
181 *mem_device = acpi_driver_data(device);
182 if (!(*mem_device)) {
183 printk(KERN_ERR "\n driver data not found");
190 static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
192 unsigned long current_status;
195 /* Get device present/absent information from the _STA */
196 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle, "_STA",
197 NULL, ¤t_status)))
200 * Check for device status. Device should be
201 * present/enabled/functioning.
203 if (!((current_status & ACPI_MEMORY_STA_PRESENT)
204 && (current_status & ACPI_MEMORY_STA_ENABLED)
205 && (current_status & ACPI_MEMORY_STA_FUNCTIONAL)))
211 static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
213 int result, num_enabled = 0;
214 struct acpi_memory_info *info;
218 /* Get the range from the _CRS */
219 result = acpi_memory_get_device_resources(mem_device);
221 printk(KERN_ERR PREFIX "get_device_resources failed\n");
222 mem_device->state = MEMORY_INVALID_STATE;
226 node = acpi_get_node(mem_device->device->handle);
228 * Tell the VM there is more memory here...
229 * Note: Assume that this function returns zero on success
230 * We don't have memory-hot-add rollback function,now.
231 * (i.e. memory-hot-remove function)
233 list_for_each_entry(info, &mem_device->res_list, list) {
234 u64 start_pfn, end_pfn;
236 start_pfn = info->start_addr >> PAGE_SHIFT;
237 end_pfn = (info->start_addr + info->length - 1) >> PAGE_SHIFT;
239 if (pfn_valid(start_pfn) || pfn_valid(end_pfn)) {
240 /* already enabled. try next area */
245 result = add_memory(node, info->start_addr, info->length);
252 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "\nadd_memory failed\n"));
253 mem_device->state = MEMORY_INVALID_STATE;
260 static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
263 struct acpi_object_list arg_list;
264 union acpi_object arg;
265 unsigned long current_status;
268 /* Issue the _EJ0 command */
270 arg_list.pointer = &arg;
271 arg.type = ACPI_TYPE_INTEGER;
272 arg.integer.value = 1;
273 status = acpi_evaluate_object(mem_device->device->handle,
274 "_EJ0", &arg_list, NULL);
275 /* Return on _EJ0 failure */
276 if (ACPI_FAILURE(status)) {
277 ACPI_EXCEPTION((AE_INFO, status, "_EJ0 failed"));
281 /* Evalute _STA to check if the device is disabled */
282 status = acpi_evaluate_integer(mem_device->device->handle, "_STA",
283 NULL, ¤t_status);
284 if (ACPI_FAILURE(status))
287 /* Check for device status. Device should be disabled */
288 if (current_status & ACPI_MEMORY_STA_ENABLED)
294 static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
297 struct acpi_memory_info *info, *n;
301 * Ask the VM to offline this memory range.
302 * Note: Assume that this function returns zero on success
304 list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
306 result = remove_memory(info->start_addr, info->length);
313 /* Power-off and eject the device */
314 result = acpi_memory_powerdown_device(mem_device);
316 /* Set the status of the device to invalid */
317 mem_device->state = MEMORY_INVALID_STATE;
321 mem_device->state = MEMORY_POWER_OFF_STATE;
325 static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
327 struct acpi_memory_device *mem_device;
328 struct acpi_device *device;
332 case ACPI_NOTIFY_BUS_CHECK:
333 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
334 "\nReceived BUS CHECK notification for device\n"));
336 case ACPI_NOTIFY_DEVICE_CHECK:
337 if (event == ACPI_NOTIFY_DEVICE_CHECK)
338 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
339 "\nReceived DEVICE CHECK notification for device\n"));
340 if (acpi_memory_get_device(handle, &mem_device)) {
341 printk(KERN_ERR PREFIX "Cannot find driver data\n");
345 if (!acpi_memory_check_device(mem_device)) {
346 if (acpi_memory_enable_device(mem_device))
347 printk(KERN_ERR PREFIX
348 "Cannot enable memory device\n");
351 case ACPI_NOTIFY_EJECT_REQUEST:
352 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
353 "\nReceived EJECT REQUEST notification for device\n"));
355 if (acpi_bus_get_device(handle, &device)) {
356 printk(KERN_ERR PREFIX "Device doesn't exist\n");
359 mem_device = acpi_driver_data(device);
361 printk(KERN_ERR PREFIX "Driver Data is NULL\n");
366 * Currently disabling memory device from kernel mode
367 * TBD: Can also be disabled from user mode scripts
368 * TBD: Can also be disabled by Callback registration
369 * with generic sysfs driver
371 if (acpi_memory_disable_device(mem_device))
372 printk(KERN_ERR PREFIX
373 "Disable memory device\n");
375 * TBD: Invoke acpi_bus_remove to cleanup data structures
379 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
380 "Unsupported event [0x%x]\n", event));
387 static int acpi_memory_device_add(struct acpi_device *device)
390 struct acpi_memory_device *mem_device = NULL;
396 mem_device = kmalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
399 memset(mem_device, 0, sizeof(struct acpi_memory_device));
401 INIT_LIST_HEAD(&mem_device->res_list);
402 mem_device->device->handle = device->handle;
403 mem_device->device = device;
404 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
405 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
406 acpi_driver_data(device) = mem_device;
408 /* Get the range from the _CRS */
409 result = acpi_memory_get_device_resources(mem_device);
415 /* Set the device state */
416 mem_device->state = MEMORY_POWER_ON_STATE;
418 printk(KERN_INFO "%s \n", acpi_device_name(device));
423 static int acpi_memory_device_remove(struct acpi_device *device, int type)
425 struct acpi_memory_device *mem_device = NULL;
428 if (!device || !acpi_driver_data(device))
431 mem_device = (struct acpi_memory_device *)acpi_driver_data(device);
437 static int acpi_memory_device_start (struct acpi_device *device)
439 struct acpi_memory_device *mem_device;
442 mem_device = acpi_driver_data(device);
444 if (!acpi_memory_check_device(mem_device)) {
445 /* call add_memory func */
446 result = acpi_memory_enable_device(mem_device);
448 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
449 "Error in acpi_memory_enable_device\n"));
455 * Helper function to check for memory device
457 static acpi_status is_memory_device(acpi_handle handle)
461 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
462 struct acpi_device_info *info;
465 status = acpi_get_object_info(handle, &buffer);
466 if (ACPI_FAILURE(status))
469 info = buffer.pointer;
470 if (!(info->valid & ACPI_VALID_HID)) {
471 acpi_os_free(buffer.pointer);
475 hardware_id = info->hardware_id.value;
476 if ((hardware_id == NULL) ||
477 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
480 acpi_os_free(buffer.pointer);
485 acpi_memory_register_notify_handler(acpi_handle handle,
486 u32 level, void *ctxt, void **retv)
491 status = is_memory_device(handle);
492 if (ACPI_FAILURE(status)){
493 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
494 return AE_OK; /* continue */
497 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
498 acpi_memory_device_notify, NULL);
504 acpi_memory_deregister_notify_handler(acpi_handle handle,
505 u32 level, void *ctxt, void **retv)
510 status = is_memory_device(handle);
511 if (ACPI_FAILURE(status)){
512 ACPI_EXCEPTION((AE_INFO, status, "handle is no memory device"));
513 return AE_OK; /* continue */
516 status = acpi_remove_notify_handler(handle,
518 acpi_memory_device_notify);
520 return AE_OK; /* continue */
523 static int __init acpi_memory_device_init(void)
529 result = acpi_bus_register_driver(&acpi_memory_device_driver);
534 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
536 acpi_memory_register_notify_handler,
539 if (ACPI_FAILURE(status)) {
540 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
541 acpi_bus_unregister_driver(&acpi_memory_device_driver);
548 static void __exit acpi_memory_device_exit(void)
554 * Adding this to un-install notification handlers for all the device
557 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
559 acpi_memory_deregister_notify_handler,
562 if (ACPI_FAILURE(status))
563 ACPI_EXCEPTION((AE_INFO, status, "walk_namespace failed"));
565 acpi_bus_unregister_driver(&acpi_memory_device_driver);
570 module_init(acpi_memory_device_init);
571 module_exit(acpi_memory_device_exit);