2 * Copyright (C) 2012 Intel Corporation
3 * Author: Liu Jinsong <jinsong.liu@intel.com>
4 * Author: Jiang Yunhong <yunhong.jiang@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
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/types.h>
22 #include <linux/acpi.h>
23 #include <acpi/acpi_drivers.h>
25 #include <xen/interface/platform.h>
26 #include <asm/xen/hypercall.h>
28 #define PREFIX "ACPI:xen_memory_hotplug:"
30 struct acpi_memory_info
{
31 struct list_head list
;
32 u64 start_addr
; /* Memory Range start physical addr */
33 u64 length
; /* Memory Range length */
34 unsigned short caching
; /* memory cache attribute */
35 unsigned short write_protect
; /* memory read/write attribute */
36 /* copied from buffer getting from _CRS */
37 unsigned int enabled
:1;
40 struct acpi_memory_device
{
41 struct acpi_device
*device
;
42 struct list_head res_list
;
45 static bool acpi_hotmem_initialized __read_mostly
;
47 static int xen_hotadd_memory(int pxm
, struct acpi_memory_info
*info
)
50 struct xen_platform_op op
;
52 op
.cmd
= XENPF_mem_hotadd
;
53 op
.u
.mem_add
.spfn
= info
->start_addr
>> PAGE_SHIFT
;
54 op
.u
.mem_add
.epfn
= (info
->start_addr
+ info
->length
) >> PAGE_SHIFT
;
55 op
.u
.mem_add
.pxm
= pxm
;
57 rc
= HYPERVISOR_dom0_op(&op
);
59 pr_err(PREFIX
"Xen Hotplug Memory Add failed on "
60 "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
61 (unsigned long)info
->start_addr
,
62 (unsigned long)(info
->start_addr
+ info
->length
),
68 static int xen_acpi_memory_enable_device(struct acpi_memory_device
*mem_device
)
72 struct acpi_memory_info
*info
;
77 pxm
= xen_acpi_get_pxm(mem_device
->device
->handle
);
81 list_for_each_entry(info
, &mem_device
->res_list
, list
) {
82 if (info
->enabled
) { /* just sanity check...*/
90 result
= xen_hotadd_memory(pxm
, info
);
104 acpi_memory_get_resource(struct acpi_resource
*resource
, void *context
)
106 struct acpi_memory_device
*mem_device
= context
;
107 struct acpi_resource_address64 address64
;
108 struct acpi_memory_info
*info
, *new;
111 status
= acpi_resource_to_address64(resource
, &address64
);
112 if (ACPI_FAILURE(status
) ||
113 (address64
.resource_type
!= ACPI_MEMORY_RANGE
))
116 list_for_each_entry(info
, &mem_device
->res_list
, list
) {
117 if ((info
->caching
== address64
.info
.mem
.caching
) &&
118 (info
->write_protect
== address64
.info
.mem
.write_protect
) &&
119 (info
->start_addr
+ info
->length
== address64
.minimum
)) {
120 info
->length
+= address64
.address_length
;
125 new = kzalloc(sizeof(struct acpi_memory_info
), GFP_KERNEL
);
129 INIT_LIST_HEAD(&new->list
);
130 new->caching
= address64
.info
.mem
.caching
;
131 new->write_protect
= address64
.info
.mem
.write_protect
;
132 new->start_addr
= address64
.minimum
;
133 new->length
= address64
.address_length
;
134 list_add_tail(&new->list
, &mem_device
->res_list
);
140 acpi_memory_get_device_resources(struct acpi_memory_device
*mem_device
)
143 struct acpi_memory_info
*info
, *n
;
145 if (!list_empty(&mem_device
->res_list
))
148 status
= acpi_walk_resources(mem_device
->device
->handle
,
149 METHOD_NAME__CRS
, acpi_memory_get_resource
, mem_device
);
151 if (ACPI_FAILURE(status
)) {
152 list_for_each_entry_safe(info
, n
, &mem_device
->res_list
, list
)
154 INIT_LIST_HEAD(&mem_device
->res_list
);
161 static int acpi_memory_get_device(acpi_handle handle
,
162 struct acpi_memory_device
**mem_device
)
164 struct acpi_device
*device
= NULL
;
167 acpi_scan_lock_acquire();
169 acpi_bus_get_device(handle
, &device
);
174 * Now add the notified device. This creates the acpi_device
175 * and invokes .add function
177 result
= acpi_bus_scan(handle
);
179 pr_warn(PREFIX
"ACPI namespace scan failed\n");
183 result
= acpi_bus_get_device(handle
, &device
);
185 pr_warn(PREFIX
"Missing device object\n");
191 *mem_device
= acpi_driver_data(device
);
192 if (!(*mem_device
)) {
193 pr_err(PREFIX
"driver data not found\n");
199 acpi_scan_lock_release();
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
,
209 "_STA", 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_disable_device(struct acpi_memory_device
*mem_device
)
225 pr_debug(PREFIX
"Xen does not support memory hotremove\n");
230 static void acpi_memory_device_notify(acpi_handle handle
, u32 event
, void *data
)
232 struct acpi_memory_device
*mem_device
;
233 struct acpi_device
*device
;
234 u32 ost_code
= ACPI_OST_SC_NON_SPECIFIC_FAILURE
; /* default */
237 case ACPI_NOTIFY_BUS_CHECK
:
238 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
239 "\nReceived BUS CHECK notification for device\n"));
241 case ACPI_NOTIFY_DEVICE_CHECK
:
242 if (event
== ACPI_NOTIFY_DEVICE_CHECK
)
243 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
244 "\nReceived DEVICE CHECK notification for device\n"));
246 if (acpi_memory_get_device(handle
, &mem_device
)) {
247 pr_err(PREFIX
"Cannot find driver data\n");
251 ost_code
= ACPI_OST_SC_SUCCESS
;
254 case ACPI_NOTIFY_EJECT_REQUEST
:
255 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
256 "\nReceived EJECT REQUEST notification for device\n"));
258 acpi_scan_lock_acquire();
259 if (acpi_bus_get_device(handle
, &device
)) {
260 acpi_scan_lock_release();
261 pr_err(PREFIX
"Device doesn't exist\n");
264 mem_device
= acpi_driver_data(device
);
266 acpi_scan_lock_release();
267 pr_err(PREFIX
"Driver Data is NULL\n");
272 * TBD: implement acpi_memory_disable_device and invoke
273 * acpi_bus_remove if Xen support hotremove in the future
275 acpi_memory_disable_device(mem_device
);
276 acpi_scan_lock_release();
280 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
281 "Unsupported event [0x%x]\n", event
));
282 /* non-hotplug event; possibly handled by other handler */
286 (void) acpi_evaluate_hotplug_ost(handle
, event
, ost_code
, NULL
);
290 static int xen_acpi_memory_device_add(struct acpi_device
*device
)
293 struct acpi_memory_device
*mem_device
= NULL
;
299 mem_device
= kzalloc(sizeof(struct acpi_memory_device
), GFP_KERNEL
);
303 INIT_LIST_HEAD(&mem_device
->res_list
);
304 mem_device
->device
= device
;
305 sprintf(acpi_device_name(device
), "%s", ACPI_MEMORY_DEVICE_NAME
);
306 sprintf(acpi_device_class(device
), "%s", ACPI_MEMORY_DEVICE_CLASS
);
307 device
->driver_data
= mem_device
;
309 /* Get the range from the _CRS */
310 result
= acpi_memory_get_device_resources(mem_device
);
317 * For booting existed memory devices, early boot code has recognized
318 * memory area by EFI/E820. If DSDT shows these memory devices on boot,
319 * hotplug is not necessary for them.
320 * For hot-added memory devices during runtime, it need hypercall to
321 * Xen hypervisor to add memory.
323 if (!acpi_hotmem_initialized
)
326 if (!acpi_memory_check_device(mem_device
))
327 result
= xen_acpi_memory_enable_device(mem_device
);
332 static int xen_acpi_memory_device_remove(struct acpi_device
*device
)
334 struct acpi_memory_device
*mem_device
= NULL
;
336 if (!device
|| !acpi_driver_data(device
))
339 mem_device
= acpi_driver_data(device
);
346 * Helper function to check for memory device
348 static acpi_status
is_memory_device(acpi_handle handle
)
352 struct acpi_device_info
*info
;
354 status
= acpi_get_object_info(handle
, &info
);
355 if (ACPI_FAILURE(status
))
358 if (!(info
->valid
& ACPI_VALID_HID
)) {
363 hardware_id
= info
->hardware_id
.string
;
364 if ((hardware_id
== NULL
) ||
365 (strcmp(hardware_id
, ACPI_MEMORY_DEVICE_HID
)))
373 acpi_memory_register_notify_handler(acpi_handle handle
,
374 u32 level
, void *ctxt
, void **retv
)
378 status
= is_memory_device(handle
);
379 if (ACPI_FAILURE(status
))
380 return AE_OK
; /* continue */
382 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
383 acpi_memory_device_notify
, NULL
);
389 acpi_memory_deregister_notify_handler(acpi_handle handle
,
390 u32 level
, void *ctxt
, void **retv
)
394 status
= is_memory_device(handle
);
395 if (ACPI_FAILURE(status
))
396 return AE_OK
; /* continue */
398 status
= acpi_remove_notify_handler(handle
,
400 acpi_memory_device_notify
);
402 return AE_OK
; /* continue */
405 static const struct acpi_device_id memory_device_ids
[] = {
406 {ACPI_MEMORY_DEVICE_HID
, 0},
409 MODULE_DEVICE_TABLE(acpi
, memory_device_ids
);
411 static struct acpi_driver xen_acpi_memory_device_driver
= {
412 .name
= "acpi_memhotplug",
413 .class = ACPI_MEMORY_DEVICE_CLASS
,
414 .ids
= memory_device_ids
,
416 .add
= xen_acpi_memory_device_add
,
417 .remove
= xen_acpi_memory_device_remove
,
421 static int __init
xen_acpi_memory_device_init(void)
426 if (!xen_initial_domain())
429 /* unregister the stub which only used to reserve driver space */
430 xen_stub_memory_device_exit();
432 result
= acpi_bus_register_driver(&xen_acpi_memory_device_driver
);
434 xen_stub_memory_device_init();
438 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
440 acpi_memory_register_notify_handler
,
443 if (ACPI_FAILURE(status
)) {
444 pr_warn(PREFIX
"walk_namespace failed\n");
445 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver
);
446 xen_stub_memory_device_init();
450 acpi_hotmem_initialized
= true;
454 static void __exit
xen_acpi_memory_device_exit(void)
458 if (!xen_initial_domain())
461 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
463 acpi_memory_deregister_notify_handler
,
465 if (ACPI_FAILURE(status
))
466 pr_warn(PREFIX
"walk_namespace failed\n");
468 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver
);
471 * stub reserve space again to prevent any chance of native
474 xen_stub_memory_device_init();
478 module_init(xen_acpi_memory_device_init
);
479 module_exit(xen_acpi_memory_device_exit
);
480 ACPI_MODULE_NAME("xen-acpi-memhotplug");
481 MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
482 MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
483 MODULE_LICENSE("GPL");