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
);
61 static struct acpi_driver acpi_memory_device_driver
= {
62 .name
= ACPI_MEMORY_DEVICE_DRIVER_NAME
,
63 .class = ACPI_MEMORY_DEVICE_CLASS
,
64 .ids
= ACPI_MEMORY_DEVICE_HID
,
66 .add
= acpi_memory_device_add
,
67 .remove
= acpi_memory_device_remove
,
71 struct acpi_memory_device
{
73 unsigned int state
; /* State of the memory device */
74 unsigned short caching
; /* memory cache attribute */
75 unsigned short write_protect
; /* memory read/write attribute */
76 u64 start_addr
; /* Memory Range start physical addr */
77 u64 length
; /* Memory Range length */
81 acpi_memory_get_device_resources(struct acpi_memory_device
*mem_device
)
84 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
85 struct acpi_resource
*resource
= NULL
;
86 struct acpi_resource_address64 address64
;
88 ACPI_FUNCTION_TRACE("acpi_memory_get_device_resources");
90 /* Get the range from the _CRS */
91 status
= acpi_get_current_resources(mem_device
->handle
, &buffer
);
92 if (ACPI_FAILURE(status
))
93 return_VALUE(-EINVAL
);
95 resource
= (struct acpi_resource
*)buffer
.pointer
;
96 status
= acpi_resource_to_address64(resource
, &address64
);
97 if (ACPI_SUCCESS(status
)) {
98 if (address64
.resource_type
== ACPI_MEMORY_RANGE
) {
99 /* Populate the structure */
100 mem_device
->caching
= address64
.info
.mem
.caching
;
101 mem_device
->write_protect
=
102 address64
.info
.mem
.write_protect
;
103 mem_device
->start_addr
= address64
.minimum
;
104 mem_device
->length
= address64
.address_length
;
108 acpi_os_free(buffer
.pointer
);
113 acpi_memory_get_device(acpi_handle handle
,
114 struct acpi_memory_device
**mem_device
)
118 struct acpi_device
*device
= NULL
;
119 struct acpi_device
*pdevice
= NULL
;
121 ACPI_FUNCTION_TRACE("acpi_memory_get_device");
123 if (!acpi_bus_get_device(handle
, &device
) && device
)
126 status
= acpi_get_parent(handle
, &phandle
);
127 if (ACPI_FAILURE(status
)) {
128 ACPI_EXCEPTION((AE_INFO
, status
, "Cannot find acpi parent"));
129 return_VALUE(-EINVAL
);
132 /* Get the parent device */
133 status
= acpi_bus_get_device(phandle
, &pdevice
);
134 if (ACPI_FAILURE(status
)) {
135 ACPI_EXCEPTION((AE_INFO
, status
, "Cannot get acpi bus device"));
136 return_VALUE(-EINVAL
);
140 * Now add the notified device. This creates the acpi_device
141 * and invokes .add function
143 status
= acpi_bus_add(&device
, pdevice
, handle
, ACPI_BUS_TYPE_DEVICE
);
144 if (ACPI_FAILURE(status
)) {
145 ACPI_EXCEPTION((AE_INFO
, status
, "Cannot add acpi bus"));
146 return_VALUE(-EINVAL
);
150 *mem_device
= acpi_driver_data(device
);
151 if (!(*mem_device
)) {
152 printk(KERN_ERR
"\n driver data not found");
153 return_VALUE(-ENODEV
);
159 static int acpi_memory_check_device(struct acpi_memory_device
*mem_device
)
161 unsigned long current_status
;
163 ACPI_FUNCTION_TRACE("acpi_memory_check_device");
165 /* Get device present/absent information from the _STA */
166 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device
->handle
, "_STA",
167 NULL
, ¤t_status
)))
168 return_VALUE(-ENODEV
);
170 * Check for device status. Device should be
171 * present/enabled/functioning.
173 if (!((current_status
& ACPI_MEMORY_STA_PRESENT
)
174 && (current_status
& ACPI_MEMORY_STA_ENABLED
)
175 && (current_status
& ACPI_MEMORY_STA_FUNCTIONAL
)))
176 return_VALUE(-ENODEV
);
181 static int acpi_memory_enable_device(struct acpi_memory_device
*mem_device
)
185 ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
187 /* Get the range from the _CRS */
188 result
= acpi_memory_get_device_resources(mem_device
);
190 ACPI_ERROR((AE_INFO
, "get_device_resources failed"));
191 mem_device
->state
= MEMORY_INVALID_STATE
;
196 * Tell the VM there is more memory here...
197 * Note: Assume that this function returns zero on success
199 result
= add_memory(mem_device
->start_addr
, mem_device
->length
);
201 ACPI_ERROR((AE_INFO
, "add_memory failed"));
202 mem_device
->state
= MEMORY_INVALID_STATE
;
209 static int acpi_memory_powerdown_device(struct acpi_memory_device
*mem_device
)
212 struct acpi_object_list arg_list
;
213 union acpi_object arg
;
214 unsigned long current_status
;
216 ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
218 /* Issue the _EJ0 command */
220 arg_list
.pointer
= &arg
;
221 arg
.type
= ACPI_TYPE_INTEGER
;
222 arg
.integer
.value
= 1;
223 status
= acpi_evaluate_object(mem_device
->handle
,
224 "_EJ0", &arg_list
, NULL
);
225 /* Return on _EJ0 failure */
226 if (ACPI_FAILURE(status
)) {
227 ACPI_EXCEPTION((AE_INFO
, status
, "_EJ0 failed"));
228 return_VALUE(-ENODEV
);
231 /* Evalute _STA to check if the device is disabled */
232 status
= acpi_evaluate_integer(mem_device
->handle
, "_STA",
233 NULL
, ¤t_status
);
234 if (ACPI_FAILURE(status
))
235 return_VALUE(-ENODEV
);
237 /* Check for device status. Device should be disabled */
238 if (current_status
& ACPI_MEMORY_STA_ENABLED
)
239 return_VALUE(-EINVAL
);
244 static int acpi_memory_disable_device(struct acpi_memory_device
*mem_device
)
247 u64 start
= mem_device
->start_addr
;
248 u64 len
= mem_device
->length
;
250 ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
253 * Ask the VM to offline this memory range.
254 * Note: Assume that this function returns zero on success
256 result
= remove_memory(start
, len
);
258 return_VALUE(result
);
260 /* Power-off and eject the device */
261 result
= acpi_memory_powerdown_device(mem_device
);
263 /* Set the status of the device to invalid */
264 mem_device
->state
= MEMORY_INVALID_STATE
;
268 mem_device
->state
= MEMORY_POWER_OFF_STATE
;
272 static void acpi_memory_device_notify(acpi_handle handle
, u32 event
, void *data
)
274 struct acpi_memory_device
*mem_device
;
275 struct acpi_device
*device
;
277 ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
280 case ACPI_NOTIFY_BUS_CHECK
:
281 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
282 "\nReceived BUS CHECK notification for device\n"));
284 case ACPI_NOTIFY_DEVICE_CHECK
:
285 if (event
== ACPI_NOTIFY_DEVICE_CHECK
)
286 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
287 "\nReceived DEVICE CHECK notification for device\n"));
288 if (acpi_memory_get_device(handle
, &mem_device
)) {
289 ACPI_ERROR((AE_INFO
, "Cannot find driver data"));
293 if (!acpi_memory_check_device(mem_device
)) {
294 if (acpi_memory_enable_device(mem_device
))
296 "Cannot enable memory device"));
299 case ACPI_NOTIFY_EJECT_REQUEST
:
300 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
301 "\nReceived EJECT REQUEST notification for device\n"));
303 if (acpi_bus_get_device(handle
, &device
)) {
304 ACPI_ERROR((AE_INFO
, "Device doesn't exist"));
307 mem_device
= acpi_driver_data(device
);
309 ACPI_ERROR((AE_INFO
, "Driver Data is NULL"));
314 * Currently disabling memory device from kernel mode
315 * TBD: Can also be disabled from user mode scripts
316 * TBD: Can also be disabled by Callback registration
317 * with generic sysfs driver
319 if (acpi_memory_disable_device(mem_device
))
321 "Disable memory device\n"));
323 * TBD: Invoke acpi_bus_remove to cleanup data structures
327 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
328 "Unsupported event [0x%x]\n", event
));
335 static int acpi_memory_device_add(struct acpi_device
*device
)
338 struct acpi_memory_device
*mem_device
= NULL
;
340 ACPI_FUNCTION_TRACE("acpi_memory_device_add");
343 return_VALUE(-EINVAL
);
345 mem_device
= kmalloc(sizeof(struct acpi_memory_device
), GFP_KERNEL
);
347 return_VALUE(-ENOMEM
);
348 memset(mem_device
, 0, sizeof(struct acpi_memory_device
));
350 mem_device
->handle
= device
->handle
;
351 sprintf(acpi_device_name(device
), "%s", ACPI_MEMORY_DEVICE_NAME
);
352 sprintf(acpi_device_class(device
), "%s", ACPI_MEMORY_DEVICE_CLASS
);
353 acpi_driver_data(device
) = mem_device
;
355 /* Get the range from the _CRS */
356 result
= acpi_memory_get_device_resources(mem_device
);
359 return_VALUE(result
);
362 /* Set the device state */
363 mem_device
->state
= MEMORY_POWER_ON_STATE
;
365 printk(KERN_INFO
"%s \n", acpi_device_name(device
));
367 return_VALUE(result
);
370 static int acpi_memory_device_remove(struct acpi_device
*device
, int type
)
372 struct acpi_memory_device
*mem_device
= NULL
;
374 ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
376 if (!device
|| !acpi_driver_data(device
))
377 return_VALUE(-EINVAL
);
379 mem_device
= (struct acpi_memory_device
*)acpi_driver_data(device
);
386 * Helper function to check for memory device
388 static acpi_status
is_memory_device(acpi_handle handle
)
392 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
393 struct acpi_device_info
*info
;
395 ACPI_FUNCTION_TRACE("is_memory_device");
397 status
= acpi_get_object_info(handle
, &buffer
);
398 if (ACPI_FAILURE(status
))
399 return_ACPI_STATUS(status
);
401 info
= buffer
.pointer
;
402 if (!(info
->valid
& ACPI_VALID_HID
)) {
403 acpi_os_free(buffer
.pointer
);
404 return_ACPI_STATUS(AE_ERROR
);
407 hardware_id
= info
->hardware_id
.value
;
408 if ((hardware_id
== NULL
) ||
409 (strcmp(hardware_id
, ACPI_MEMORY_DEVICE_HID
)))
412 acpi_os_free(buffer
.pointer
);
413 return_ACPI_STATUS(status
);
417 acpi_memory_register_notify_handler(acpi_handle handle
,
418 u32 level
, void *ctxt
, void **retv
)
422 ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
424 status
= is_memory_device(handle
);
425 if (ACPI_FAILURE(status
)){
426 ACPI_EXCEPTION((AE_INFO
, status
, "handle is no memory device"));
427 return_ACPI_STATUS(AE_OK
); /* continue */
430 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
431 acpi_memory_device_notify
, NULL
);
433 return_ACPI_STATUS(AE_OK
);
437 acpi_memory_deregister_notify_handler(acpi_handle handle
,
438 u32 level
, void *ctxt
, void **retv
)
442 ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
444 status
= is_memory_device(handle
);
445 if (ACPI_FAILURE(status
)){
446 ACPI_EXCEPTION((AE_INFO
, status
, "handle is no memory device"));
447 return_ACPI_STATUS(AE_OK
); /* continue */
450 status
= acpi_remove_notify_handler(handle
,
452 acpi_memory_device_notify
);
454 return_ACPI_STATUS(AE_OK
); /* continue */
457 static int __init
acpi_memory_device_init(void)
462 ACPI_FUNCTION_TRACE("acpi_memory_device_init");
464 result
= acpi_bus_register_driver(&acpi_memory_device_driver
);
467 return_VALUE(-ENODEV
);
469 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
471 acpi_memory_register_notify_handler
,
474 if (ACPI_FAILURE(status
)) {
475 ACPI_EXCEPTION((AE_INFO
, status
, "walk_namespace failed"));
476 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
477 return_VALUE(-ENODEV
);
483 static void __exit
acpi_memory_device_exit(void)
487 ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
490 * Adding this to un-install notification handlers for all the device
493 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
495 acpi_memory_deregister_notify_handler
,
498 if (ACPI_FAILURE(status
))
499 ACPI_EXCEPTION((AE_INFO
, status
, "walk_namespace failed"));
501 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
506 module_init(acpi_memory_device_init
);
507 module_exit(acpi_memory_device_exit
);