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
;
231 node
= acpi_get_node(mem_device
->handle
);
233 * Tell the VM there is more memory here...
234 * Note: Assume that this function returns zero on success
235 * We don't have memory-hot-add rollback function,now.
236 * (i.e. memory-hot-remove function)
238 list_for_each_entry(info
, &mem_device
->res_list
, list
) {
239 u64 start_pfn
, end_pfn
;
241 start_pfn
= info
->start_addr
>> PAGE_SHIFT
;
242 end_pfn
= (info
->start_addr
+ info
->length
- 1) >> PAGE_SHIFT
;
244 if (pfn_valid(start_pfn
) || pfn_valid(end_pfn
)) {
245 /* already enabled. try next area */
250 result
= add_memory(node
, info
->start_addr
, info
->length
);
257 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "\nadd_memory failed\n"));
258 mem_device
->state
= MEMORY_INVALID_STATE
;
265 static int acpi_memory_powerdown_device(struct acpi_memory_device
*mem_device
)
268 struct acpi_object_list arg_list
;
269 union acpi_object arg
;
270 unsigned long current_status
;
272 ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
274 /* Issue the _EJ0 command */
276 arg_list
.pointer
= &arg
;
277 arg
.type
= ACPI_TYPE_INTEGER
;
278 arg
.integer
.value
= 1;
279 status
= acpi_evaluate_object(mem_device
->handle
,
280 "_EJ0", &arg_list
, NULL
);
281 /* Return on _EJ0 failure */
282 if (ACPI_FAILURE(status
)) {
283 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "_EJ0 failed.\n"));
284 return_VALUE(-ENODEV
);
287 /* Evalute _STA to check if the device is disabled */
288 status
= acpi_evaluate_integer(mem_device
->handle
, "_STA",
289 NULL
, ¤t_status
);
290 if (ACPI_FAILURE(status
))
291 return_VALUE(-ENODEV
);
293 /* Check for device status. Device should be disabled */
294 if (current_status
& ACPI_MEMORY_STA_ENABLED
)
295 return_VALUE(-EINVAL
);
300 static int acpi_memory_disable_device(struct acpi_memory_device
*mem_device
)
303 struct acpi_memory_info
*info
, *n
;
305 ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
308 * Ask the VM to offline this memory range.
309 * Note: Assume that this function returns zero on success
311 list_for_each_entry_safe(info
, n
, &mem_device
->res_list
, list
) {
313 result
= remove_memory(info
->start_addr
, info
->length
);
320 /* Power-off and eject the device */
321 result
= acpi_memory_powerdown_device(mem_device
);
323 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
324 "Device Power Down failed.\n"));
325 /* Set the status of the device to invalid */
326 mem_device
->state
= MEMORY_INVALID_STATE
;
330 mem_device
->state
= MEMORY_POWER_OFF_STATE
;
334 static void acpi_memory_device_notify(acpi_handle handle
, u32 event
, void *data
)
336 struct acpi_memory_device
*mem_device
;
337 struct acpi_device
*device
;
339 ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
342 case ACPI_NOTIFY_BUS_CHECK
:
343 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
344 "\nReceived BUS CHECK notification for device\n"));
346 case ACPI_NOTIFY_DEVICE_CHECK
:
347 if (event
== ACPI_NOTIFY_DEVICE_CHECK
)
348 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
349 "\nReceived DEVICE CHECK notification for device\n"));
350 if (acpi_memory_get_device(handle
, &mem_device
)) {
351 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
352 "Error in finding driver data\n"));
356 if (!acpi_memory_check_device(mem_device
)) {
357 if (acpi_memory_enable_device(mem_device
))
358 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
359 "Error in acpi_memory_enable_device\n"));
362 case ACPI_NOTIFY_EJECT_REQUEST
:
363 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
364 "\nReceived EJECT REQUEST notification for device\n"));
366 if (acpi_bus_get_device(handle
, &device
)) {
367 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
368 "Device doesn't exist\n"));
371 mem_device
= acpi_driver_data(device
);
373 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
374 "Driver Data is NULL\n"));
379 * Currently disabling memory device from kernel mode
380 * TBD: Can also be disabled from user mode scripts
381 * TBD: Can also be disabled by Callback registration
382 * with generic sysfs driver
384 if (acpi_memory_disable_device(mem_device
))
385 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
386 "Error in acpi_memory_disable_device\n"));
388 * TBD: Invoke acpi_bus_remove to cleanup data structures
392 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
393 "Unsupported event [0x%x]\n", event
));
400 static int acpi_memory_device_add(struct acpi_device
*device
)
403 struct acpi_memory_device
*mem_device
= NULL
;
405 ACPI_FUNCTION_TRACE("acpi_memory_device_add");
408 return_VALUE(-EINVAL
);
410 mem_device
= kmalloc(sizeof(struct acpi_memory_device
), GFP_KERNEL
);
412 return_VALUE(-ENOMEM
);
413 memset(mem_device
, 0, sizeof(struct acpi_memory_device
));
415 INIT_LIST_HEAD(&mem_device
->res_list
);
416 mem_device
->handle
= device
->handle
;
417 sprintf(acpi_device_name(device
), "%s", ACPI_MEMORY_DEVICE_NAME
);
418 sprintf(acpi_device_class(device
), "%s", ACPI_MEMORY_DEVICE_CLASS
);
419 acpi_driver_data(device
) = mem_device
;
421 /* Get the range from the _CRS */
422 result
= acpi_memory_get_device_resources(mem_device
);
425 return_VALUE(result
);
428 /* Set the device state */
429 mem_device
->state
= MEMORY_POWER_ON_STATE
;
431 printk(KERN_INFO
"%s \n", acpi_device_name(device
));
433 return_VALUE(result
);
436 static int acpi_memory_device_remove(struct acpi_device
*device
, int type
)
438 struct acpi_memory_device
*mem_device
= NULL
;
440 ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
442 if (!device
|| !acpi_driver_data(device
))
443 return_VALUE(-EINVAL
);
445 mem_device
= (struct acpi_memory_device
*)acpi_driver_data(device
);
451 static int acpi_memory_device_start (struct acpi_device
*device
)
453 struct acpi_memory_device
*mem_device
;
456 ACPI_FUNCTION_TRACE("acpi_memory_device_start");
458 mem_device
= acpi_driver_data(device
);
460 if (!acpi_memory_check_device(mem_device
)) {
461 /* call add_memory func */
462 result
= acpi_memory_enable_device(mem_device
);
464 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
465 "Error in acpi_memory_enable_device\n"));
467 return_VALUE(result
);
471 * Helper function to check for memory device
473 static acpi_status
is_memory_device(acpi_handle handle
)
477 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
478 struct acpi_device_info
*info
;
480 ACPI_FUNCTION_TRACE("is_memory_device");
482 status
= acpi_get_object_info(handle
, &buffer
);
483 if (ACPI_FAILURE(status
))
484 return_ACPI_STATUS(AE_ERROR
);
486 info
= buffer
.pointer
;
487 if (!(info
->valid
& ACPI_VALID_HID
)) {
488 acpi_os_free(buffer
.pointer
);
489 return_ACPI_STATUS(AE_ERROR
);
492 hardware_id
= info
->hardware_id
.value
;
493 if ((hardware_id
== NULL
) ||
494 (strcmp(hardware_id
, ACPI_MEMORY_DEVICE_HID
)))
497 acpi_os_free(buffer
.pointer
);
498 return_ACPI_STATUS(status
);
502 acpi_memory_register_notify_handler(acpi_handle handle
,
503 u32 level
, void *ctxt
, void **retv
)
507 ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
509 status
= is_memory_device(handle
);
510 if (ACPI_FAILURE(status
))
511 return_ACPI_STATUS(AE_OK
); /* continue */
513 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
514 acpi_memory_device_notify
, NULL
);
515 if (ACPI_FAILURE(status
)) {
516 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
517 "Error installing notify handler\n"));
518 return_ACPI_STATUS(AE_OK
); /* continue */
521 return_ACPI_STATUS(status
);
525 acpi_memory_deregister_notify_handler(acpi_handle handle
,
526 u32 level
, void *ctxt
, void **retv
)
530 ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
532 status
= is_memory_device(handle
);
533 if (ACPI_FAILURE(status
))
534 return_ACPI_STATUS(AE_OK
); /* continue */
536 status
= acpi_remove_notify_handler(handle
,
538 acpi_memory_device_notify
);
539 if (ACPI_FAILURE(status
)) {
540 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
541 "Error removing notify handler\n"));
542 return_ACPI_STATUS(AE_OK
); /* continue */
545 return_ACPI_STATUS(status
);
548 static int __init
acpi_memory_device_init(void)
553 ACPI_FUNCTION_TRACE("acpi_memory_device_init");
555 result
= acpi_bus_register_driver(&acpi_memory_device_driver
);
558 return_VALUE(-ENODEV
);
560 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
562 acpi_memory_register_notify_handler
,
565 if (ACPI_FAILURE(status
)) {
566 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "walk_namespace failed\n"));
567 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
568 return_VALUE(-ENODEV
);
574 static void __exit
acpi_memory_device_exit(void)
578 ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
581 * Adding this to un-install notification handlers for all the device
584 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
586 acpi_memory_deregister_notify_handler
,
589 if (ACPI_FAILURE(status
))
590 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "walk_namespace failed\n"));
592 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
597 module_init(acpi_memory_device_init
);
598 module_exit(acpi_memory_device_exit
);