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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/types.h>
24 #include <linux/acpi.h>
26 #include <xen/interface/platform.h>
27 #include <asm/xen/hypercall.h>
29 #define PREFIX "ACPI:xen_memory_hotplug:"
31 struct acpi_memory_info
{
32 struct list_head list
;
33 u64 start_addr
; /* Memory Range start physical addr */
34 u64 length
; /* Memory Range length */
35 unsigned short caching
; /* memory cache attribute */
36 unsigned short write_protect
; /* memory read/write attribute */
37 /* copied from buffer getting from _CRS */
38 unsigned int enabled
:1;
41 struct acpi_memory_device
{
42 struct acpi_device
*device
;
43 struct list_head res_list
;
46 static bool acpi_hotmem_initialized __read_mostly
;
48 static int xen_hotadd_memory(int pxm
, struct acpi_memory_info
*info
)
51 struct xen_platform_op op
;
53 op
.cmd
= XENPF_mem_hotadd
;
54 op
.u
.mem_add
.spfn
= info
->start_addr
>> PAGE_SHIFT
;
55 op
.u
.mem_add
.epfn
= (info
->start_addr
+ info
->length
) >> PAGE_SHIFT
;
56 op
.u
.mem_add
.pxm
= pxm
;
58 rc
= HYPERVISOR_dom0_op(&op
);
60 pr_err(PREFIX
"Xen Hotplug Memory Add failed on "
61 "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
62 (unsigned long)info
->start_addr
,
63 (unsigned long)(info
->start_addr
+ info
->length
),
69 static int xen_acpi_memory_enable_device(struct acpi_memory_device
*mem_device
)
73 struct acpi_memory_info
*info
;
78 pxm
= xen_acpi_get_pxm(mem_device
->device
->handle
);
82 list_for_each_entry(info
, &mem_device
->res_list
, list
) {
83 if (info
->enabled
) { /* just sanity check...*/
91 result
= xen_hotadd_memory(pxm
, info
);
105 acpi_memory_get_resource(struct acpi_resource
*resource
, void *context
)
107 struct acpi_memory_device
*mem_device
= context
;
108 struct acpi_resource_address64 address64
;
109 struct acpi_memory_info
*info
, *new;
112 status
= acpi_resource_to_address64(resource
, &address64
);
113 if (ACPI_FAILURE(status
) ||
114 (address64
.resource_type
!= ACPI_MEMORY_RANGE
))
117 list_for_each_entry(info
, &mem_device
->res_list
, list
) {
118 if ((info
->caching
== address64
.info
.mem
.caching
) &&
119 (info
->write_protect
== address64
.info
.mem
.write_protect
) &&
120 (info
->start_addr
+ info
->length
== address64
.minimum
)) {
121 info
->length
+= address64
.address_length
;
126 new = kzalloc(sizeof(struct acpi_memory_info
), GFP_KERNEL
);
130 INIT_LIST_HEAD(&new->list
);
131 new->caching
= address64
.info
.mem
.caching
;
132 new->write_protect
= address64
.info
.mem
.write_protect
;
133 new->start_addr
= address64
.minimum
;
134 new->length
= address64
.address_length
;
135 list_add_tail(&new->list
, &mem_device
->res_list
);
141 acpi_memory_get_device_resources(struct acpi_memory_device
*mem_device
)
144 struct acpi_memory_info
*info
, *n
;
146 if (!list_empty(&mem_device
->res_list
))
149 status
= acpi_walk_resources(mem_device
->device
->handle
,
150 METHOD_NAME__CRS
, acpi_memory_get_resource
, mem_device
);
152 if (ACPI_FAILURE(status
)) {
153 list_for_each_entry_safe(info
, n
, &mem_device
->res_list
, list
)
155 INIT_LIST_HEAD(&mem_device
->res_list
);
162 static int acpi_memory_get_device(acpi_handle handle
,
163 struct acpi_memory_device
**mem_device
)
165 struct acpi_device
*device
= NULL
;
168 acpi_scan_lock_acquire();
170 acpi_bus_get_device(handle
, &device
);
175 * Now add the notified device. This creates the acpi_device
176 * and invokes .add function
178 result
= acpi_bus_scan(handle
);
180 pr_warn(PREFIX
"ACPI namespace scan failed\n");
184 result
= acpi_bus_get_device(handle
, &device
);
186 pr_warn(PREFIX
"Missing device object\n");
192 *mem_device
= acpi_driver_data(device
);
193 if (!(*mem_device
)) {
194 pr_err(PREFIX
"driver data not found\n");
200 acpi_scan_lock_release();
204 static int acpi_memory_check_device(struct acpi_memory_device
*mem_device
)
206 unsigned long long current_status
;
208 /* Get device present/absent information from the _STA */
209 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device
->device
->handle
,
210 "_STA", NULL
, ¤t_status
)))
213 * Check for device status. Device should be
214 * present/enabled/functioning.
216 if (!((current_status
& ACPI_STA_DEVICE_PRESENT
)
217 && (current_status
& ACPI_STA_DEVICE_ENABLED
)
218 && (current_status
& ACPI_STA_DEVICE_FUNCTIONING
)))
224 static int acpi_memory_disable_device(struct acpi_memory_device
*mem_device
)
226 pr_debug(PREFIX
"Xen does not support memory hotremove\n");
231 static void acpi_memory_device_notify(acpi_handle handle
, u32 event
, void *data
)
233 struct acpi_memory_device
*mem_device
;
234 struct acpi_device
*device
;
235 u32 ost_code
= ACPI_OST_SC_NON_SPECIFIC_FAILURE
; /* default */
238 case ACPI_NOTIFY_BUS_CHECK
:
239 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
240 "\nReceived BUS CHECK notification for device\n"));
242 case ACPI_NOTIFY_DEVICE_CHECK
:
243 if (event
== ACPI_NOTIFY_DEVICE_CHECK
)
244 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
245 "\nReceived DEVICE CHECK notification for device\n"));
247 if (acpi_memory_get_device(handle
, &mem_device
)) {
248 pr_err(PREFIX
"Cannot find driver data\n");
252 ost_code
= ACPI_OST_SC_SUCCESS
;
255 case ACPI_NOTIFY_EJECT_REQUEST
:
256 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
257 "\nReceived EJECT REQUEST notification for device\n"));
259 acpi_scan_lock_acquire();
260 if (acpi_bus_get_device(handle
, &device
)) {
261 acpi_scan_lock_release();
262 pr_err(PREFIX
"Device doesn't exist\n");
265 mem_device
= acpi_driver_data(device
);
267 acpi_scan_lock_release();
268 pr_err(PREFIX
"Driver Data is NULL\n");
273 * TBD: implement acpi_memory_disable_device and invoke
274 * acpi_bus_remove if Xen support hotremove in the future
276 acpi_memory_disable_device(mem_device
);
277 acpi_scan_lock_release();
281 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
282 "Unsupported event [0x%x]\n", event
));
283 /* non-hotplug event; possibly handled by other handler */
287 (void) acpi_evaluate_hotplug_ost(handle
, event
, ost_code
, NULL
);
291 static int xen_acpi_memory_device_add(struct acpi_device
*device
)
294 struct acpi_memory_device
*mem_device
= NULL
;
300 mem_device
= kzalloc(sizeof(struct acpi_memory_device
), GFP_KERNEL
);
304 INIT_LIST_HEAD(&mem_device
->res_list
);
305 mem_device
->device
= device
;
306 sprintf(acpi_device_name(device
), "%s", ACPI_MEMORY_DEVICE_NAME
);
307 sprintf(acpi_device_class(device
), "%s", ACPI_MEMORY_DEVICE_CLASS
);
308 device
->driver_data
= mem_device
;
310 /* Get the range from the _CRS */
311 result
= acpi_memory_get_device_resources(mem_device
);
318 * For booting existed memory devices, early boot code has recognized
319 * memory area by EFI/E820. If DSDT shows these memory devices on boot,
320 * hotplug is not necessary for them.
321 * For hot-added memory devices during runtime, it need hypercall to
322 * Xen hypervisor to add memory.
324 if (!acpi_hotmem_initialized
)
327 if (!acpi_memory_check_device(mem_device
))
328 result
= xen_acpi_memory_enable_device(mem_device
);
333 static int xen_acpi_memory_device_remove(struct acpi_device
*device
)
335 struct acpi_memory_device
*mem_device
= NULL
;
337 if (!device
|| !acpi_driver_data(device
))
340 mem_device
= acpi_driver_data(device
);
347 * Helper function to check for memory device
349 static acpi_status
is_memory_device(acpi_handle handle
)
353 struct acpi_device_info
*info
;
355 status
= acpi_get_object_info(handle
, &info
);
356 if (ACPI_FAILURE(status
))
359 if (!(info
->valid
& ACPI_VALID_HID
)) {
364 hardware_id
= info
->hardware_id
.string
;
365 if ((hardware_id
== NULL
) ||
366 (strcmp(hardware_id
, ACPI_MEMORY_DEVICE_HID
)))
374 acpi_memory_register_notify_handler(acpi_handle handle
,
375 u32 level
, void *ctxt
, void **retv
)
379 status
= is_memory_device(handle
);
380 if (ACPI_FAILURE(status
))
381 return AE_OK
; /* continue */
383 status
= acpi_install_notify_handler(handle
, ACPI_SYSTEM_NOTIFY
,
384 acpi_memory_device_notify
, NULL
);
390 acpi_memory_deregister_notify_handler(acpi_handle handle
,
391 u32 level
, void *ctxt
, void **retv
)
395 status
= is_memory_device(handle
);
396 if (ACPI_FAILURE(status
))
397 return AE_OK
; /* continue */
399 status
= acpi_remove_notify_handler(handle
,
401 acpi_memory_device_notify
);
403 return AE_OK
; /* continue */
406 static const struct acpi_device_id memory_device_ids
[] = {
407 {ACPI_MEMORY_DEVICE_HID
, 0},
410 MODULE_DEVICE_TABLE(acpi
, memory_device_ids
);
412 static struct acpi_driver xen_acpi_memory_device_driver
= {
413 .name
= "acpi_memhotplug",
414 .class = ACPI_MEMORY_DEVICE_CLASS
,
415 .ids
= memory_device_ids
,
417 .add
= xen_acpi_memory_device_add
,
418 .remove
= xen_acpi_memory_device_remove
,
422 static int __init
xen_acpi_memory_device_init(void)
427 if (!xen_initial_domain())
430 /* unregister the stub which only used to reserve driver space */
431 xen_stub_memory_device_exit();
433 result
= acpi_bus_register_driver(&xen_acpi_memory_device_driver
);
435 xen_stub_memory_device_init();
439 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
441 acpi_memory_register_notify_handler
,
444 if (ACPI_FAILURE(status
)) {
445 pr_warn(PREFIX
"walk_namespace failed\n");
446 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver
);
447 xen_stub_memory_device_init();
451 acpi_hotmem_initialized
= true;
455 static void __exit
xen_acpi_memory_device_exit(void)
459 if (!xen_initial_domain())
462 status
= acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
464 acpi_memory_deregister_notify_handler
,
466 if (ACPI_FAILURE(status
))
467 pr_warn(PREFIX
"walk_namespace failed\n");
469 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver
);
472 * stub reserve space again to prevent any chance of native
475 xen_stub_memory_device_init();
479 module_init(xen_acpi_memory_device_init
);
480 module_exit(xen_acpi_memory_device_exit
);
481 ACPI_MODULE_NAME("xen-acpi-memhotplug");
482 MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
483 MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
484 MODULE_LICENSE("GPL");