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8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/types.h>
14#include <linux/acpi.h>
15#include <xen/acpi.h>
16#include <xen/interface/platform.h>
17#include <asm/xen/hypercall.h>
18
19#define PREFIX "ACPI:xen_memory_hotplug:"
20
21struct acpi_memory_info {
22 struct list_head list;
23 u64 start_addr;
24 u64 length;
25 unsigned short caching;
26 unsigned short write_protect;
27
28 unsigned int enabled:1;
29};
30
31struct acpi_memory_device {
32 struct acpi_device *device;
33 struct list_head res_list;
34};
35
36static bool acpi_hotmem_initialized __read_mostly;
37
38static int xen_hotadd_memory(int pxm, struct acpi_memory_info *info)
39{
40 int rc;
41 struct xen_platform_op op;
42
43 op.cmd = XENPF_mem_hotadd;
44 op.u.mem_add.spfn = info->start_addr >> PAGE_SHIFT;
45 op.u.mem_add.epfn = (info->start_addr + info->length) >> PAGE_SHIFT;
46 op.u.mem_add.pxm = pxm;
47
48 rc = HYPERVISOR_dom0_op(&op);
49 if (rc)
50 pr_err(PREFIX "Xen Hotplug Memory Add failed on "
51 "0x%lx -> 0x%lx, _PXM: %d, error: %d\n",
52 (unsigned long)info->start_addr,
53 (unsigned long)(info->start_addr + info->length),
54 pxm, rc);
55
56 return rc;
57}
58
59static int xen_acpi_memory_enable_device(struct acpi_memory_device *mem_device)
60{
61 int pxm, result;
62 int num_enabled = 0;
63 struct acpi_memory_info *info;
64
65 if (!mem_device)
66 return -EINVAL;
67
68 pxm = xen_acpi_get_pxm(mem_device->device->handle);
69 if (pxm < 0)
70 return pxm;
71
72 list_for_each_entry(info, &mem_device->res_list, list) {
73 if (info->enabled) {
74 num_enabled++;
75 continue;
76 }
77
78 if (!info->length)
79 continue;
80
81 result = xen_hotadd_memory(pxm, info);
82 if (result)
83 continue;
84 info->enabled = 1;
85 num_enabled++;
86 }
87
88 if (!num_enabled)
89 return -ENODEV;
90
91 return 0;
92}
93
94static acpi_status
95acpi_memory_get_resource(struct acpi_resource *resource, void *context)
96{
97 struct acpi_memory_device *mem_device = context;
98 struct acpi_resource_address64 address64;
99 struct acpi_memory_info *info, *new;
100 acpi_status status;
101
102 status = acpi_resource_to_address64(resource, &address64);
103 if (ACPI_FAILURE(status) ||
104 (address64.resource_type != ACPI_MEMORY_RANGE))
105 return AE_OK;
106
107 list_for_each_entry(info, &mem_device->res_list, list) {
108 if ((info->caching == address64.info.mem.caching) &&
109 (info->write_protect == address64.info.mem.write_protect) &&
110 (info->start_addr + info->length == address64.address.minimum)) {
111 info->length += address64.address.address_length;
112 return AE_OK;
113 }
114 }
115
116 new = kzalloc(sizeof(struct acpi_memory_info), GFP_KERNEL);
117 if (!new)
118 return AE_ERROR;
119
120 INIT_LIST_HEAD(&new->list);
121 new->caching = address64.info.mem.caching;
122 new->write_protect = address64.info.mem.write_protect;
123 new->start_addr = address64.address.minimum;
124 new->length = address64.address.address_length;
125 list_add_tail(&new->list, &mem_device->res_list);
126
127 return AE_OK;
128}
129
130static int
131acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
132{
133 acpi_status status;
134 struct acpi_memory_info *info, *n;
135
136 if (!list_empty(&mem_device->res_list))
137 return 0;
138
139 status = acpi_walk_resources(mem_device->device->handle,
140 METHOD_NAME__CRS, acpi_memory_get_resource, mem_device);
141
142 if (ACPI_FAILURE(status)) {
143 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
144 kfree(info);
145 INIT_LIST_HEAD(&mem_device->res_list);
146 return -EINVAL;
147 }
148
149 return 0;
150}
151
152static int acpi_memory_get_device(acpi_handle handle,
153 struct acpi_memory_device **mem_device)
154{
155 struct acpi_device *device = NULL;
156 int result = 0;
157
158 acpi_scan_lock_acquire();
159
160 acpi_bus_get_device(handle, &device);
161 if (acpi_device_enumerated(device))
162 goto end;
163
164
165
166
167
168 result = acpi_bus_scan(handle);
169 if (result) {
170 pr_warn(PREFIX "ACPI namespace scan failed\n");
171 result = -EINVAL;
172 goto out;
173 }
174 device = NULL;
175 acpi_bus_get_device(handle, &device);
176 if (!acpi_device_enumerated(device)) {
177 pr_warn(PREFIX "Missing device object\n");
178 result = -EINVAL;
179 goto out;
180 }
181
182end:
183 *mem_device = acpi_driver_data(device);
184 if (!(*mem_device)) {
185 pr_err(PREFIX "driver data not found\n");
186 result = -ENODEV;
187 goto out;
188 }
189
190out:
191 acpi_scan_lock_release();
192 return result;
193}
194
195static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
196{
197 unsigned long long current_status;
198
199
200 if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
201 "_STA", NULL, ¤t_status)))
202 return -ENODEV;
203
204
205
206
207 if (!((current_status & ACPI_STA_DEVICE_PRESENT)
208 && (current_status & ACPI_STA_DEVICE_ENABLED)
209 && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
210 return -ENODEV;
211
212 return 0;
213}
214
215static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
216{
217 pr_debug(PREFIX "Xen does not support memory hotremove\n");
218
219 return -ENOSYS;
220}
221
222static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data)
223{
224 struct acpi_memory_device *mem_device;
225 struct acpi_device *device;
226 u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
227
228 switch (event) {
229 case ACPI_NOTIFY_BUS_CHECK:
230 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
231 "\nReceived BUS CHECK notification for device\n"));
232 fallthrough;
233 case ACPI_NOTIFY_DEVICE_CHECK:
234 if (event == ACPI_NOTIFY_DEVICE_CHECK)
235 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
236 "\nReceived DEVICE CHECK notification for device\n"));
237
238 if (acpi_memory_get_device(handle, &mem_device)) {
239 pr_err(PREFIX "Cannot find driver data\n");
240 break;
241 }
242
243 ost_code = ACPI_OST_SC_SUCCESS;
244 break;
245
246 case ACPI_NOTIFY_EJECT_REQUEST:
247 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
248 "\nReceived EJECT REQUEST notification for device\n"));
249
250 acpi_scan_lock_acquire();
251 if (acpi_bus_get_device(handle, &device)) {
252 acpi_scan_lock_release();
253 pr_err(PREFIX "Device doesn't exist\n");
254 break;
255 }
256 mem_device = acpi_driver_data(device);
257 if (!mem_device) {
258 acpi_scan_lock_release();
259 pr_err(PREFIX "Driver Data is NULL\n");
260 break;
261 }
262
263
264
265
266
267 acpi_memory_disable_device(mem_device);
268 acpi_scan_lock_release();
269 break;
270
271 default:
272 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
273 "Unsupported event [0x%x]\n", event));
274
275 return;
276 }
277
278 (void) acpi_evaluate_ost(handle, event, ost_code, NULL);
279 return;
280}
281
282static int xen_acpi_memory_device_add(struct acpi_device *device)
283{
284 int result;
285 struct acpi_memory_device *mem_device = NULL;
286
287
288 if (!device)
289 return -EINVAL;
290
291 mem_device = kzalloc(sizeof(struct acpi_memory_device), GFP_KERNEL);
292 if (!mem_device)
293 return -ENOMEM;
294
295 INIT_LIST_HEAD(&mem_device->res_list);
296 mem_device->device = device;
297 sprintf(acpi_device_name(device), "%s", ACPI_MEMORY_DEVICE_NAME);
298 sprintf(acpi_device_class(device), "%s", ACPI_MEMORY_DEVICE_CLASS);
299 device->driver_data = mem_device;
300
301
302 result = acpi_memory_get_device_resources(mem_device);
303 if (result) {
304 kfree(mem_device);
305 return result;
306 }
307
308
309
310
311
312
313
314
315 if (!acpi_hotmem_initialized)
316 return 0;
317
318 if (!acpi_memory_check_device(mem_device))
319 result = xen_acpi_memory_enable_device(mem_device);
320
321 return result;
322}
323
324static int xen_acpi_memory_device_remove(struct acpi_device *device)
325{
326 struct acpi_memory_device *mem_device = NULL;
327
328 if (!device || !acpi_driver_data(device))
329 return -EINVAL;
330
331 mem_device = acpi_driver_data(device);
332 kfree(mem_device);
333
334 return 0;
335}
336
337
338
339
340static acpi_status is_memory_device(acpi_handle handle)
341{
342 char *hardware_id;
343 acpi_status status;
344 struct acpi_device_info *info;
345
346 status = acpi_get_object_info(handle, &info);
347 if (ACPI_FAILURE(status))
348 return status;
349
350 if (!(info->valid & ACPI_VALID_HID)) {
351 kfree(info);
352 return AE_ERROR;
353 }
354
355 hardware_id = info->hardware_id.string;
356 if ((hardware_id == NULL) ||
357 (strcmp(hardware_id, ACPI_MEMORY_DEVICE_HID)))
358 status = AE_ERROR;
359
360 kfree(info);
361 return status;
362}
363
364static acpi_status
365acpi_memory_register_notify_handler(acpi_handle handle,
366 u32 level, void *ctxt, void **retv)
367{
368 acpi_status status;
369
370 status = is_memory_device(handle);
371 if (ACPI_FAILURE(status))
372 return AE_OK;
373
374 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
375 acpi_memory_device_notify, NULL);
376
377 return AE_OK;
378}
379
380static acpi_status
381acpi_memory_deregister_notify_handler(acpi_handle handle,
382 u32 level, void *ctxt, void **retv)
383{
384 acpi_status status;
385
386 status = is_memory_device(handle);
387 if (ACPI_FAILURE(status))
388 return AE_OK;
389
390 status = acpi_remove_notify_handler(handle,
391 ACPI_SYSTEM_NOTIFY,
392 acpi_memory_device_notify);
393
394 return AE_OK;
395}
396
397static const struct acpi_device_id memory_device_ids[] = {
398 {ACPI_MEMORY_DEVICE_HID, 0},
399 {"", 0},
400};
401MODULE_DEVICE_TABLE(acpi, memory_device_ids);
402
403static struct acpi_driver xen_acpi_memory_device_driver = {
404 .name = "acpi_memhotplug",
405 .class = ACPI_MEMORY_DEVICE_CLASS,
406 .ids = memory_device_ids,
407 .ops = {
408 .add = xen_acpi_memory_device_add,
409 .remove = xen_acpi_memory_device_remove,
410 },
411};
412
413static int __init xen_acpi_memory_device_init(void)
414{
415 int result;
416 acpi_status status;
417
418 if (!xen_initial_domain())
419 return -ENODEV;
420
421
422 xen_stub_memory_device_exit();
423
424 result = acpi_bus_register_driver(&xen_acpi_memory_device_driver);
425 if (result < 0) {
426 xen_stub_memory_device_init();
427 return -ENODEV;
428 }
429
430 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
431 ACPI_UINT32_MAX,
432 acpi_memory_register_notify_handler,
433 NULL, NULL, NULL);
434
435 if (ACPI_FAILURE(status)) {
436 pr_warn(PREFIX "walk_namespace failed\n");
437 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
438 xen_stub_memory_device_init();
439 return -ENODEV;
440 }
441
442 acpi_hotmem_initialized = true;
443 return 0;
444}
445
446static void __exit xen_acpi_memory_device_exit(void)
447{
448 acpi_status status;
449
450 if (!xen_initial_domain())
451 return;
452
453 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
454 ACPI_UINT32_MAX,
455 acpi_memory_deregister_notify_handler,
456 NULL, NULL, NULL);
457 if (ACPI_FAILURE(status))
458 pr_warn(PREFIX "walk_namespace failed\n");
459
460 acpi_bus_unregister_driver(&xen_acpi_memory_device_driver);
461
462
463
464
465
466 xen_stub_memory_device_init();
467 return;
468}
469
470module_init(xen_acpi_memory_device_init);
471module_exit(xen_acpi_memory_device_exit);
472ACPI_MODULE_NAME("xen-acpi-memhotplug");
473MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>");
474MODULE_DESCRIPTION("Xen Hotplug Mem Driver");
475MODULE_LICENSE("GPL");
476
