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 <linux/acpi.h>
35 #include <acpi/acpi_drivers.h>
37 #define ACPI_MEMORY_DEVICE_CLASS "memory"
38 #define ACPI_MEMORY_DEVICE_HID "PNP0C80"
39 #define ACPI_MEMORY_DEVICE_NAME "Hotplug Mem Device"
41 #define _COMPONENT ACPI_MEMORY_DEVICE_COMPONENT
44 #define PREFIX "ACPI:memory_hp:"
46 ACPI_MODULE_NAME("acpi_memhotplug");
47 MODULE_AUTHOR("Naveen B S <naveen.b.s@intel.com>");
48 MODULE_DESCRIPTION("Hotplug Mem Driver");
49 MODULE_LICENSE("GPL");
51 /* Memory Device States */
52 #define MEMORY_INVALID_STATE 0
53 #define MEMORY_POWER_ON_STATE 1
54 #define MEMORY_POWER_OFF_STATE 2
56 static int acpi_memory_device_add(struct acpi_device
*device
);
57 static int acpi_memory_device_remove(struct acpi_device
*device
, int type
);
59 static const struct acpi_device_id memory_device_ids
[] = {
60 {ACPI_MEMORY_DEVICE_HID
, 0},
63 MODULE_DEVICE_TABLE(acpi
, memory_device_ids
);
65 static struct acpi_driver acpi_memory_device_driver
= {
66 .name
= "acpi_memhotplug",
67 .class = ACPI_MEMORY_DEVICE_CLASS
,
68 .ids
= memory_device_ids
,
70 .add
= acpi_memory_device_add
,
71 .remove
= acpi_memory_device_remove
,
75 struct acpi_memory_info
{
76 struct list_head list
;
77 u64 start_addr
; /* Memory Range start physical addr */
78 u64 length
; /* Memory Range length */
79 unsigned short caching
; /* memory cache attribute */
80 unsigned short write_protect
; /* memory read/write attribute */
81 unsigned int enabled
:1;
82 unsigned int failed
:1;
85 struct acpi_memory_device
{
86 struct acpi_device
* device
;
87 unsigned int state
; /* State of the memory device */
88 struct list_head res_list
;
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_free_device_resources(struct acpi_memory_device
*mem_device
)
131 struct acpi_memory_info
*info
, *n
;
133 list_for_each_entry_safe(info
, n
, &mem_device
->res_list
, list
)
135 INIT_LIST_HEAD(&mem_device
->res_list
);
139 acpi_memory_get_device_resources(struct acpi_memory_device
*mem_device
)
143 if (!list_empty(&mem_device
->res_list
))
146 status
= acpi_walk_resources(mem_device
->device
->handle
, METHOD_NAME__CRS
,
147 acpi_memory_get_resource
, mem_device
);
148 if (ACPI_FAILURE(status
)) {
149 acpi_memory_free_device_resources(mem_device
);
157 acpi_memory_get_device(acpi_handle handle
,
158 struct acpi_memory_device
**mem_device
)
162 struct acpi_device
*device
= NULL
;
163 struct acpi_device
*pdevice
= NULL
;
167 if (!acpi_bus_get_device(handle
, &device
) && device
)
170 status
= acpi_get_parent(handle
, &phandle
);
171 if (ACPI_FAILURE(status
)) {
172 ACPI_EXCEPTION((AE_INFO
, status
, "Cannot find acpi parent"));
176 /* Get the parent device */
177 result
= acpi_bus_get_device(phandle
, &pdevice
);
179 acpi_handle_warn(phandle
, "Cannot get acpi bus device\n");
184 * Now add the notified device. This creates the acpi_device
185 * and invokes .add function
187 result
= acpi_bus_add(&device
, pdevice
, handle
, ACPI_BUS_TYPE_DEVICE
);
189 acpi_handle_warn(handle
, "Cannot add acpi bus\n");
194 *mem_device
= acpi_driver_data(device
);
195 if (!(*mem_device
)) {
196 dev_err(&device
->dev
, "driver data not found\n");
203 static int acpi_memory_check_device(struct acpi_memory_device
*mem_device
)
205 unsigned long long current_status
;
207 /* Get device present/absent information from the _STA */
208 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device
->device
->handle
, "_STA",
209 NULL
, ¤t_status
)))
212 * Check for device status. Device should be
213 * present/enabled/functioning.
215 if (!((current_status
& ACPI_STA_DEVICE_PRESENT
)
216 && (current_status
& ACPI_STA_DEVICE_ENABLED
)
217 && (current_status
& ACPI_STA_DEVICE_FUNCTIONING
)))
223 static int acpi_memory_enable_device(struct acpi_memory_device
*mem_device
)
225 int result
, num_enabled
= 0;
226 struct acpi_memory_info
*info
;
230 /* Get the range from the _CRS */
231 result
= acpi_memory_get_device_resources(mem_device
);
233 dev_err(&mem_device
->device
->dev
,
234 "get_device_resources failed\n");
235 mem_device
->state
= MEMORY_INVALID_STATE
;
239 node
= acpi_get_node(mem_device
->device
->handle
);
241 * Tell the VM there is more memory here...
242 * Note: Assume that this function returns zero on success
243 * We don't have memory-hot-add rollback function,now.
244 * (i.e. memory-hot-remove function)
246 list_for_each_entry(info
, &mem_device
->res_list
, list
) {
247 if (info
->enabled
) { /* just sanity check...*/
252 * If the memory block size is zero, please ignore it.
253 * Don't try to do the following memory hotplug flowchart.
258 node
= memory_add_physaddr_to_nid(info
->start_addr
);
260 result
= add_memory(node
, info
->start_addr
, info
->length
);
263 * If the memory block has been used by the kernel, add_memory()
264 * returns -EEXIST. If add_memory() returns the other error, it
265 * means that this memory block is not used by the kernel.
267 if (result
&& result
!= -EEXIST
) {
275 * Add num_enable even if add_memory() returns -EEXIST, so the
276 * device is bound to this driver.
281 dev_err(&mem_device
->device
->dev
, "add_memory failed\n");
282 mem_device
->state
= MEMORY_INVALID_STATE
;
286 * Sometimes the memory device will contain several memory blocks.
287 * When one memory block is hot-added to the system memory, it will
288 * be regarded as a success.
289 * Otherwise if the last memory block can't be hot-added to the system
290 * memory, it will be failure and the memory device can't be bound with
296 static int acpi_memory_remove_memory(struct acpi_memory_device
*mem_device
)
299 struct acpi_memory_info
*info
, *n
;
301 list_for_each_entry_safe(info
, n
, &mem_device
->res_list
, list
) {
303 /* The kernel does not use this memory block */
308 * The kernel uses this memory block, but it may be not
313 result
= remove_memory(info
->start_addr
, info
->length
);
317 list_del(&info
->list
);
324 static void acpi_memory_device_notify(acpi_handle handle
, u32 event
, void *data
)
326 struct acpi_memory_device
*mem_device
;
327 struct acpi_device
*device
;
328 struct acpi_eject_event
*ej_event
= NULL
;
329 u32 ost_code
= ACPI_OST_SC_NON_SPECIFIC_FAILURE
; /* default */
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 acpi_handle_err(handle
, "Cannot find driver data\n");
345 if (acpi_memory_check_device(mem_device
))
348 if (acpi_memory_enable_device(mem_device
)) {
349 acpi_handle_err(handle
,"Cannot enable memory device\n");
353 ost_code
= ACPI_OST_SC_SUCCESS
;
356 case ACPI_NOTIFY_EJECT_REQUEST
:
357 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
358 "\nReceived EJECT REQUEST notification for device\n"));
360 if (acpi_bus_get_device(handle
, &device
)) {
361 acpi_handle_err(handle
, "Device doesn't exist\n");
364 mem_device
= acpi_driver_data(device
);
366 acpi_handle_err(handle
, "Driver Data is NULL\n");
370 ej_event
= kmalloc(sizeof(*ej_event
), GFP_KERNEL
);
372 pr_err(PREFIX
"No memory, dropping EJECT\n");
376 ej_event
->handle
= handle
;
377 ej_event
->event
= ACPI_NOTIFY_EJECT_REQUEST
;
378 acpi_os_hotplug_execute(acpi_bus_hot_remove_device
,
381 /* eject is performed asynchronously */
384 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
385 "Unsupported event [0x%x]\n", event
));
387 /* non-hotplug event; possibly handled by other handler */
391 /* Inform firmware that the hotplug operation has completed */
392 (void) acpi_evaluate_hotplug_ost(handle
, event
, ost_code
, NULL
);
396 static void acpi_memory_device_free(struct acpi_memory_device
*mem_device
)
401 acpi_memory_free_device_resources(mem_device
);
405 static int acpi_memory_device_add(struct acpi_device
*device
)
408 struct acpi_memory_device
*mem_device
= NULL
;
414 mem_device
= kzalloc(sizeof(struct acpi_memory_device
), GFP_KERNEL
);
418 INIT_LIST_HEAD(&mem_device
->res_list
);
419 mem_device
->device
= device
;
420 sprintf(acpi_device_name(device
), "%s", ACPI_MEMORY_DEVICE_NAME
);
421 sprintf(acpi_device_class(device
), "%s", ACPI_MEMORY_DEVICE_CLASS
);
422 device
->driver_data
= mem_device
;
424 /* Get the range from the _CRS */
425 result
= acpi_memory_get_device_resources(mem_device
);
431 /* Set the device state */
432 mem_device
->state
= MEMORY_POWER_ON_STATE
;
434 pr_debug("%s\n", acpi_device_name(device
));
436 if (!acpi_memory_check_device(mem_device
)) {
437 /* call add_memory func */
438 result
= acpi_memory_enable_device(mem_device
);
440 dev_err(&device
->dev
,
441 "Error in acpi_memory_enable_device\n");
442 acpi_memory_device_free(mem_device
);
448 static int acpi_memory_device_remove(struct acpi_device
*device
, int type
)
450 struct acpi_memory_device
*mem_device
= NULL
;
453 if (!device
|| !acpi_driver_data(device
))
456 mem_device
= acpi_driver_data(device
);
458 result
= acpi_memory_remove_memory(mem_device
);
462 acpi_memory_device_free(mem_device
);
468 * Helper function to check for memory device
470 static acpi_status
is_memory_device(acpi_handle handle
)
474 struct acpi_device_info
*info
;
476 status
= acpi_get_object_info(handle
, &info
);
477 if (ACPI_FAILURE(status
))
480 if (!(info
->valid
& ACPI_VALID_HID
)) {
485 hardware_id
= info
->hardware_id
.string
;
486 if ((hardware_id
== NULL
) ||
487 (strcmp(hardware_id
, ACPI_MEMORY_DEVICE_HID
)))
495 acpi_memory_register_notify_handler(acpi_handle handle
,
496 u32 level
, void *ctxt
, void **retv
)
501 status
= is_memory_device(handle
);
502 if (ACPI_FAILURE(status
))
503 return AE_OK
; /* continue */
505 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
506 acpi_memory_device_notify
, NULL
);
512 acpi_memory_deregister_notify_handler(acpi_handle handle
,
513 u32 level
, void *ctxt
, void **retv
)
518 status
= is_memory_device(handle
);
519 if (ACPI_FAILURE(status
))
520 return AE_OK
; /* continue */
522 status
= acpi_remove_notify_handler(handle
,
524 acpi_memory_device_notify
);
526 return AE_OK
; /* continue */
529 static int __init
acpi_memory_device_init(void)
535 result
= acpi_bus_register_driver(&acpi_memory_device_driver
);
540 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
542 acpi_memory_register_notify_handler
, NULL
,
545 if (ACPI_FAILURE(status
)) {
546 ACPI_EXCEPTION((AE_INFO
, status
, "walk_namespace failed"));
547 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
554 static void __exit
acpi_memory_device_exit(void)
560 * Adding this to un-install notification handlers for all the device
563 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
565 acpi_memory_deregister_notify_handler
, NULL
,
568 if (ACPI_FAILURE(status
))
569 ACPI_EXCEPTION((AE_INFO
, status
, "walk_namespace failed"));
571 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
576 module_init(acpi_memory_device_init
);
577 module_exit(acpi_memory_device_exit
);