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_DEBUG_PRINT((ACPI_DB_ERROR
, "Error in acpi_get_parent\n"));
129 return_VALUE(-EINVAL
);
132 /* Get the parent device */
133 status
= acpi_bus_get_device(phandle
, &pdevice
);
134 if (ACPI_FAILURE(status
)) {
135 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
136 "Error in acpi_bus_get_device\n"));
137 return_VALUE(-EINVAL
);
141 * Now add the notified device. This creates the acpi_device
142 * and invokes .add function
144 status
= acpi_bus_add(&device
, pdevice
, handle
, ACPI_BUS_TYPE_DEVICE
);
145 if (ACPI_FAILURE(status
)) {
146 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "Error in acpi_bus_add\n"));
147 return_VALUE(-EINVAL
);
151 *mem_device
= acpi_driver_data(device
);
152 if (!(*mem_device
)) {
153 printk(KERN_ERR
"\n driver data not found");
154 return_VALUE(-ENODEV
);
160 static int acpi_memory_check_device(struct acpi_memory_device
*mem_device
)
162 unsigned long current_status
;
164 ACPI_FUNCTION_TRACE("acpi_memory_check_device");
166 /* Get device present/absent information from the _STA */
167 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device
->handle
, "_STA",
168 NULL
, ¤t_status
)))
169 return_VALUE(-ENODEV
);
171 * Check for device status. Device should be
172 * present/enabled/functioning.
174 if (!((current_status
& ACPI_MEMORY_STA_PRESENT
)
175 && (current_status
& ACPI_MEMORY_STA_ENABLED
)
176 && (current_status
& ACPI_MEMORY_STA_FUNCTIONAL
)))
177 return_VALUE(-ENODEV
);
182 static int acpi_memory_enable_device(struct acpi_memory_device
*mem_device
)
186 ACPI_FUNCTION_TRACE("acpi_memory_enable_device");
188 /* Get the range from the _CRS */
189 result
= acpi_memory_get_device_resources(mem_device
);
191 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
192 "\nget_device_resources failed\n"));
193 mem_device
->state
= MEMORY_INVALID_STATE
;
198 * Tell the VM there is more memory here...
199 * Note: Assume that this function returns zero on success
201 result
= add_memory(mem_device
->start_addr
, mem_device
->length
);
203 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "\nadd_memory failed\n"));
204 mem_device
->state
= MEMORY_INVALID_STATE
;
211 static int acpi_memory_powerdown_device(struct acpi_memory_device
*mem_device
)
214 struct acpi_object_list arg_list
;
215 union acpi_object arg
;
216 unsigned long current_status
;
218 ACPI_FUNCTION_TRACE("acpi_memory_powerdown_device");
220 /* Issue the _EJ0 command */
222 arg_list
.pointer
= &arg
;
223 arg
.type
= ACPI_TYPE_INTEGER
;
224 arg
.integer
.value
= 1;
225 status
= acpi_evaluate_object(mem_device
->handle
,
226 "_EJ0", &arg_list
, NULL
);
227 /* Return on _EJ0 failure */
228 if (ACPI_FAILURE(status
)) {
229 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "_EJ0 failed.\n"));
230 return_VALUE(-ENODEV
);
233 /* Evalute _STA to check if the device is disabled */
234 status
= acpi_evaluate_integer(mem_device
->handle
, "_STA",
235 NULL
, ¤t_status
);
236 if (ACPI_FAILURE(status
))
237 return_VALUE(-ENODEV
);
239 /* Check for device status. Device should be disabled */
240 if (current_status
& ACPI_MEMORY_STA_ENABLED
)
241 return_VALUE(-EINVAL
);
246 static int acpi_memory_disable_device(struct acpi_memory_device
*mem_device
)
249 u64 start
= mem_device
->start_addr
;
250 u64 len
= mem_device
->length
;
252 ACPI_FUNCTION_TRACE("acpi_memory_disable_device");
255 * Ask the VM to offline this memory range.
256 * Note: Assume that this function returns zero on success
258 result
= remove_memory(start
, len
);
260 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "Hot-Remove failed.\n"));
261 return_VALUE(result
);
264 /* Power-off and eject the device */
265 result
= acpi_memory_powerdown_device(mem_device
);
267 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
268 "Device Power Down failed.\n"));
269 /* Set the status of the device to invalid */
270 mem_device
->state
= MEMORY_INVALID_STATE
;
274 mem_device
->state
= MEMORY_POWER_OFF_STATE
;
278 static void acpi_memory_device_notify(acpi_handle handle
, u32 event
, void *data
)
280 struct acpi_memory_device
*mem_device
;
281 struct acpi_device
*device
;
283 ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
286 case ACPI_NOTIFY_BUS_CHECK
:
287 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
288 "\nReceived BUS CHECK notification for device\n"));
290 case ACPI_NOTIFY_DEVICE_CHECK
:
291 if (event
== ACPI_NOTIFY_DEVICE_CHECK
)
292 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
293 "\nReceived DEVICE CHECK notification for device\n"));
294 if (acpi_memory_get_device(handle
, &mem_device
)) {
295 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
296 "Error in finding driver data\n"));
300 if (!acpi_memory_check_device(mem_device
)) {
301 if (acpi_memory_enable_device(mem_device
))
302 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
303 "Error in acpi_memory_enable_device\n"));
306 case ACPI_NOTIFY_EJECT_REQUEST
:
307 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
308 "\nReceived EJECT REQUEST notification for device\n"));
310 if (acpi_bus_get_device(handle
, &device
)) {
311 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
312 "Device doesn't exist\n"));
315 mem_device
= acpi_driver_data(device
);
317 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
318 "Driver Data is NULL\n"));
323 * Currently disabling memory device from kernel mode
324 * TBD: Can also be disabled from user mode scripts
325 * TBD: Can also be disabled by Callback registration
326 * with generic sysfs driver
328 if (acpi_memory_disable_device(mem_device
))
329 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
330 "Error in acpi_memory_disable_device\n"));
332 * TBD: Invoke acpi_bus_remove to cleanup data structures
336 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
337 "Unsupported event [0x%x]\n", event
));
344 static int acpi_memory_device_add(struct acpi_device
*device
)
347 struct acpi_memory_device
*mem_device
= NULL
;
349 ACPI_FUNCTION_TRACE("acpi_memory_device_add");
352 return_VALUE(-EINVAL
);
354 mem_device
= kmalloc(sizeof(struct acpi_memory_device
), GFP_KERNEL
);
356 return_VALUE(-ENOMEM
);
357 memset(mem_device
, 0, sizeof(struct acpi_memory_device
));
359 mem_device
->handle
= device
->handle
;
360 sprintf(acpi_device_name(device
), "%s", ACPI_MEMORY_DEVICE_NAME
);
361 sprintf(acpi_device_class(device
), "%s", ACPI_MEMORY_DEVICE_CLASS
);
362 acpi_driver_data(device
) = mem_device
;
364 /* Get the range from the _CRS */
365 result
= acpi_memory_get_device_resources(mem_device
);
368 return_VALUE(result
);
371 /* Set the device state */
372 mem_device
->state
= MEMORY_POWER_ON_STATE
;
374 printk(KERN_INFO
"%s \n", acpi_device_name(device
));
376 return_VALUE(result
);
379 static int acpi_memory_device_remove(struct acpi_device
*device
, int type
)
381 struct acpi_memory_device
*mem_device
= NULL
;
383 ACPI_FUNCTION_TRACE("acpi_memory_device_remove");
385 if (!device
|| !acpi_driver_data(device
))
386 return_VALUE(-EINVAL
);
388 mem_device
= (struct acpi_memory_device
*)acpi_driver_data(device
);
395 * Helper function to check for memory device
397 static acpi_status
is_memory_device(acpi_handle handle
)
401 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
402 struct acpi_device_info
*info
;
404 ACPI_FUNCTION_TRACE("is_memory_device");
406 status
= acpi_get_object_info(handle
, &buffer
);
407 if (ACPI_FAILURE(status
))
408 return_ACPI_STATUS(AE_ERROR
);
410 info
= buffer
.pointer
;
411 if (!(info
->valid
& ACPI_VALID_HID
)) {
412 acpi_os_free(buffer
.pointer
);
413 return_ACPI_STATUS(AE_ERROR
);
416 hardware_id
= info
->hardware_id
.value
;
417 if ((hardware_id
== NULL
) ||
418 (strcmp(hardware_id
, ACPI_MEMORY_DEVICE_HID
)))
421 acpi_os_free(buffer
.pointer
);
422 return_ACPI_STATUS(status
);
426 acpi_memory_register_notify_handler(acpi_handle handle
,
427 u32 level
, void *ctxt
, void **retv
)
431 ACPI_FUNCTION_TRACE("acpi_memory_register_notify_handler");
433 status
= is_memory_device(handle
);
434 if (ACPI_FAILURE(status
))
435 return_ACPI_STATUS(AE_OK
); /* continue */
437 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
438 acpi_memory_device_notify
, NULL
);
439 if (ACPI_FAILURE(status
)) {
440 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
441 "Error installing notify handler\n"));
442 return_ACPI_STATUS(AE_OK
); /* continue */
445 return_ACPI_STATUS(status
);
449 acpi_memory_deregister_notify_handler(acpi_handle handle
,
450 u32 level
, void *ctxt
, void **retv
)
454 ACPI_FUNCTION_TRACE("acpi_memory_deregister_notify_handler");
456 status
= is_memory_device(handle
);
457 if (ACPI_FAILURE(status
))
458 return_ACPI_STATUS(AE_OK
); /* continue */
460 status
= acpi_remove_notify_handler(handle
,
462 acpi_memory_device_notify
);
463 if (ACPI_FAILURE(status
)) {
464 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
,
465 "Error removing notify handler\n"));
466 return_ACPI_STATUS(AE_OK
); /* continue */
469 return_ACPI_STATUS(status
);
472 static int __init
acpi_memory_device_init(void)
477 ACPI_FUNCTION_TRACE("acpi_memory_device_init");
479 result
= acpi_bus_register_driver(&acpi_memory_device_driver
);
482 return_VALUE(-ENODEV
);
484 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
486 acpi_memory_register_notify_handler
,
489 if (ACPI_FAILURE(status
)) {
490 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "walk_namespace failed\n"));
491 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
492 return_VALUE(-ENODEV
);
498 static void __exit
acpi_memory_device_exit(void)
502 ACPI_FUNCTION_TRACE("acpi_memory_device_exit");
505 * Adding this to un-install notification handlers for all the device
508 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
510 acpi_memory_deregister_notify_handler
,
513 if (ACPI_FAILURE(status
))
514 ACPI_DEBUG_PRINT((ACPI_DB_ERROR
, "walk_namespace failed\n"));
516 acpi_bus_unregister_driver(&acpi_memory_device_driver
);
521 module_init(acpi_memory_device_init
);
522 module_exit(acpi_memory_device_exit
);