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39adc483 LJ |
1 | /* |
2 | * Copyright (C) 2012 Intel Corporation | |
3 | * Author: Liu Jinsong <jinsong.liu@intel.com> | |
4 | * Author: Jiang Yunhong <yunhong.jiang@intel.com> | |
5 | * | |
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. | |
10 | * | |
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 | |
15 | * details. | |
16 | */ | |
17 | ||
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/types.h> | |
22 | #include <linux/cpu.h> | |
23 | #include <linux/acpi.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <acpi/acpi_bus.h> | |
26 | #include <acpi/acpi_drivers.h> | |
27 | #include <acpi/processor.h> | |
28 | ||
29 | #include <xen/acpi.h> | |
30 | #include <xen/interface/platform.h> | |
31 | #include <asm/xen/hypercall.h> | |
32 | ||
33 | #define PREFIX "ACPI:xen_cpu_hotplug:" | |
34 | ||
35 | #define INSTALL_NOTIFY_HANDLER 0 | |
36 | #define UNINSTALL_NOTIFY_HANDLER 1 | |
37 | ||
38 | static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr); | |
39 | ||
40 | /* -------------------------------------------------------------------------- | |
41 | Driver Interface | |
42 | -------------------------------------------------------------------------- */ | |
43 | ||
44 | static int xen_acpi_processor_enable(struct acpi_device *device) | |
45 | { | |
46 | acpi_status status = 0; | |
47 | unsigned long long value; | |
48 | union acpi_object object = { 0 }; | |
49 | struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; | |
50 | struct acpi_processor *pr; | |
51 | ||
52 | pr = acpi_driver_data(device); | |
53 | if (!pr) { | |
54 | pr_err(PREFIX "Cannot find driver data\n"); | |
55 | return -EINVAL; | |
56 | } | |
57 | ||
58 | if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) { | |
59 | /* Declared with "Processor" statement; match ProcessorID */ | |
60 | status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer); | |
61 | if (ACPI_FAILURE(status)) { | |
62 | pr_err(PREFIX "Evaluating processor object\n"); | |
63 | return -ENODEV; | |
64 | } | |
65 | ||
66 | pr->acpi_id = object.processor.proc_id; | |
67 | } else { | |
68 | /* Declared with "Device" statement; match _UID */ | |
69 | status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID, | |
70 | NULL, &value); | |
71 | if (ACPI_FAILURE(status)) { | |
72 | pr_err(PREFIX "Evaluating processor _UID\n"); | |
73 | return -ENODEV; | |
74 | } | |
75 | ||
76 | pr->acpi_id = value; | |
77 | } | |
78 | ||
79 | pr->id = xen_pcpu_id(pr->acpi_id); | |
80 | ||
81 | if ((int)pr->id < 0) | |
82 | /* This cpu is not presented at hypervisor, try to hotadd it */ | |
83 | if (ACPI_FAILURE(xen_acpi_cpu_hotadd(pr))) { | |
84 | pr_err(PREFIX "Hotadd CPU (acpi_id = %d) failed.\n", | |
85 | pr->acpi_id); | |
86 | return -ENODEV; | |
87 | } | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | static int __cpuinit xen_acpi_processor_add(struct acpi_device *device) | |
93 | { | |
94 | int ret; | |
95 | struct acpi_processor *pr; | |
96 | ||
97 | if (!device) | |
98 | return -EINVAL; | |
99 | ||
100 | pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); | |
101 | if (!pr) | |
102 | return -ENOMEM; | |
103 | ||
104 | pr->handle = device->handle; | |
105 | strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME); | |
106 | strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS); | |
107 | device->driver_data = pr; | |
108 | ||
109 | ret = xen_acpi_processor_enable(device); | |
110 | if (ret) | |
111 | pr_err(PREFIX "Error when enabling Xen processor\n"); | |
112 | ||
113 | return ret; | |
114 | } | |
115 | ||
77be36de | 116 | static int xen_acpi_processor_remove(struct acpi_device *device) |
39adc483 LJ |
117 | { |
118 | struct acpi_processor *pr; | |
119 | ||
120 | if (!device) | |
121 | return -EINVAL; | |
122 | ||
123 | pr = acpi_driver_data(device); | |
124 | if (!pr) | |
125 | return -EINVAL; | |
126 | ||
127 | kfree(pr); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | /*-------------------------------------------------------------- | |
132 | Acpi processor hotplug support | |
133 | --------------------------------------------------------------*/ | |
134 | ||
135 | static int is_processor_present(acpi_handle handle) | |
136 | { | |
137 | acpi_status status; | |
138 | unsigned long long sta = 0; | |
139 | ||
140 | ||
141 | status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); | |
142 | ||
143 | if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT)) | |
144 | return 1; | |
145 | ||
146 | /* | |
147 | * _STA is mandatory for a processor that supports hot plug | |
148 | */ | |
149 | if (status == AE_NOT_FOUND) | |
150 | pr_info(PREFIX "Processor does not support hot plug\n"); | |
151 | else | |
152 | pr_info(PREFIX "Processor Device is not present"); | |
153 | return 0; | |
154 | } | |
155 | ||
156 | static int xen_apic_id(acpi_handle handle) | |
157 | { | |
158 | struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; | |
159 | union acpi_object *obj; | |
160 | struct acpi_madt_local_apic *lapic; | |
161 | int apic_id; | |
162 | ||
163 | if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer))) | |
164 | return -EINVAL; | |
165 | ||
166 | if (!buffer.length || !buffer.pointer) | |
167 | return -EINVAL; | |
168 | ||
169 | obj = buffer.pointer; | |
170 | if (obj->type != ACPI_TYPE_BUFFER || | |
171 | obj->buffer.length < sizeof(*lapic)) { | |
172 | kfree(buffer.pointer); | |
173 | return -EINVAL; | |
174 | } | |
175 | ||
176 | lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer; | |
177 | ||
178 | if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC || | |
179 | !(lapic->lapic_flags & ACPI_MADT_ENABLED)) { | |
180 | kfree(buffer.pointer); | |
181 | return -EINVAL; | |
182 | } | |
183 | ||
184 | apic_id = (uint32_t)lapic->id; | |
185 | kfree(buffer.pointer); | |
186 | buffer.length = ACPI_ALLOCATE_BUFFER; | |
187 | buffer.pointer = NULL; | |
188 | ||
189 | return apic_id; | |
190 | } | |
191 | ||
192 | static int xen_hotadd_cpu(struct acpi_processor *pr) | |
193 | { | |
194 | int cpu_id, apic_id, pxm; | |
195 | struct xen_platform_op op; | |
196 | ||
197 | apic_id = xen_apic_id(pr->handle); | |
198 | if (apic_id < 0) { | |
199 | pr_err(PREFIX "Failed to get apic_id for acpi_id %d\n", | |
200 | pr->acpi_id); | |
201 | return -ENODEV; | |
202 | } | |
203 | ||
204 | pxm = xen_acpi_get_pxm(pr->handle); | |
205 | if (pxm < 0) { | |
206 | pr_err(PREFIX "Failed to get _PXM for acpi_id %d\n", | |
207 | pr->acpi_id); | |
208 | return pxm; | |
209 | } | |
210 | ||
211 | op.cmd = XENPF_cpu_hotadd; | |
212 | op.u.cpu_add.apic_id = apic_id; | |
213 | op.u.cpu_add.acpi_id = pr->acpi_id; | |
214 | op.u.cpu_add.pxm = pxm; | |
215 | ||
216 | cpu_id = HYPERVISOR_dom0_op(&op); | |
217 | if (cpu_id < 0) | |
218 | pr_err(PREFIX "Failed to hotadd CPU for acpi_id %d\n", | |
219 | pr->acpi_id); | |
220 | ||
221 | return cpu_id; | |
222 | } | |
223 | ||
224 | static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr) | |
225 | { | |
226 | if (!is_processor_present(pr->handle)) | |
227 | return AE_ERROR; | |
228 | ||
229 | pr->id = xen_hotadd_cpu(pr); | |
230 | if ((int)pr->id < 0) | |
231 | return AE_ERROR; | |
232 | ||
233 | /* | |
234 | * Sync with Xen hypervisor, providing new /sys/.../xen_cpuX | |
235 | * interface after cpu hotadded. | |
236 | */ | |
237 | xen_pcpu_hotplug_sync(); | |
238 | ||
239 | return AE_OK; | |
240 | } | |
241 | ||
242 | static | |
243 | int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device) | |
244 | { | |
245 | acpi_handle phandle; | |
246 | struct acpi_device *pdev; | |
247 | ||
248 | if (acpi_get_parent(handle, &phandle)) | |
249 | return -ENODEV; | |
250 | ||
251 | if (acpi_bus_get_device(phandle, &pdev)) | |
252 | return -ENODEV; | |
253 | ||
77be36de | 254 | if (acpi_bus_scan(handle)) |
39adc483 LJ |
255 | return -ENODEV; |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
260 | static int acpi_processor_device_remove(struct acpi_device *device) | |
261 | { | |
262 | pr_debug(PREFIX "Xen does not support CPU hotremove\n"); | |
263 | ||
264 | return -ENOSYS; | |
265 | } | |
266 | ||
267 | static void acpi_processor_hotplug_notify(acpi_handle handle, | |
268 | u32 event, void *data) | |
269 | { | |
270 | struct acpi_processor *pr; | |
271 | struct acpi_device *device = NULL; | |
272 | u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ | |
273 | int result; | |
274 | ||
275 | switch (event) { | |
276 | case ACPI_NOTIFY_BUS_CHECK: | |
277 | case ACPI_NOTIFY_DEVICE_CHECK: | |
278 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
279 | "Processor driver received %s event\n", | |
280 | (event == ACPI_NOTIFY_BUS_CHECK) ? | |
281 | "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK")); | |
282 | ||
283 | if (!is_processor_present(handle)) | |
284 | break; | |
285 | ||
286 | if (!acpi_bus_get_device(handle, &device)) | |
287 | break; | |
288 | ||
289 | result = acpi_processor_device_add(handle, &device); | |
290 | if (result) { | |
291 | pr_err(PREFIX "Unable to add the device\n"); | |
292 | break; | |
293 | } | |
294 | ||
295 | ost_code = ACPI_OST_SC_SUCCESS; | |
296 | break; | |
297 | ||
298 | case ACPI_NOTIFY_EJECT_REQUEST: | |
299 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
300 | "received ACPI_NOTIFY_EJECT_REQUEST\n")); | |
301 | ||
302 | if (acpi_bus_get_device(handle, &device)) { | |
303 | pr_err(PREFIX "Device don't exist, dropping EJECT\n"); | |
304 | break; | |
305 | } | |
306 | pr = acpi_driver_data(device); | |
307 | if (!pr) { | |
308 | pr_err(PREFIX "Driver data is NULL, dropping EJECT\n"); | |
309 | break; | |
310 | } | |
311 | ||
312 | /* | |
313 | * TBD: implement acpi_processor_device_remove if Xen support | |
314 | * CPU hotremove in the future. | |
315 | */ | |
316 | acpi_processor_device_remove(device); | |
317 | break; | |
318 | ||
319 | default: | |
320 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
321 | "Unsupported event [0x%x]\n", event)); | |
322 | ||
323 | /* non-hotplug event; possibly handled by other handler */ | |
324 | return; | |
325 | } | |
326 | ||
327 | (void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL); | |
328 | return; | |
329 | } | |
330 | ||
331 | static acpi_status is_processor_device(acpi_handle handle) | |
332 | { | |
333 | struct acpi_device_info *info; | |
334 | char *hid; | |
335 | acpi_status status; | |
336 | ||
337 | status = acpi_get_object_info(handle, &info); | |
338 | if (ACPI_FAILURE(status)) | |
339 | return status; | |
340 | ||
341 | if (info->type == ACPI_TYPE_PROCESSOR) { | |
342 | kfree(info); | |
343 | return AE_OK; /* found a processor object */ | |
344 | } | |
345 | ||
346 | if (!(info->valid & ACPI_VALID_HID)) { | |
347 | kfree(info); | |
348 | return AE_ERROR; | |
349 | } | |
350 | ||
351 | hid = info->hardware_id.string; | |
352 | if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) { | |
353 | kfree(info); | |
354 | return AE_ERROR; | |
355 | } | |
356 | ||
357 | kfree(info); | |
358 | return AE_OK; /* found a processor device object */ | |
359 | } | |
360 | ||
361 | static acpi_status | |
362 | processor_walk_namespace_cb(acpi_handle handle, | |
363 | u32 lvl, void *context, void **rv) | |
364 | { | |
365 | acpi_status status; | |
366 | int *action = context; | |
367 | ||
368 | status = is_processor_device(handle); | |
369 | if (ACPI_FAILURE(status)) | |
370 | return AE_OK; /* not a processor; continue to walk */ | |
371 | ||
372 | switch (*action) { | |
373 | case INSTALL_NOTIFY_HANDLER: | |
374 | acpi_install_notify_handler(handle, | |
375 | ACPI_SYSTEM_NOTIFY, | |
376 | acpi_processor_hotplug_notify, | |
377 | NULL); | |
378 | break; | |
379 | case UNINSTALL_NOTIFY_HANDLER: | |
380 | acpi_remove_notify_handler(handle, | |
381 | ACPI_SYSTEM_NOTIFY, | |
382 | acpi_processor_hotplug_notify); | |
383 | break; | |
384 | default: | |
385 | break; | |
386 | } | |
387 | ||
388 | /* found a processor; skip walking underneath */ | |
389 | return AE_CTRL_DEPTH; | |
390 | } | |
391 | ||
392 | static | |
393 | void acpi_processor_install_hotplug_notify(void) | |
394 | { | |
395 | int action = INSTALL_NOTIFY_HANDLER; | |
396 | acpi_walk_namespace(ACPI_TYPE_ANY, | |
397 | ACPI_ROOT_OBJECT, | |
398 | ACPI_UINT32_MAX, | |
399 | processor_walk_namespace_cb, NULL, &action, NULL); | |
400 | } | |
401 | ||
402 | static | |
403 | void acpi_processor_uninstall_hotplug_notify(void) | |
404 | { | |
405 | int action = UNINSTALL_NOTIFY_HANDLER; | |
406 | acpi_walk_namespace(ACPI_TYPE_ANY, | |
407 | ACPI_ROOT_OBJECT, | |
408 | ACPI_UINT32_MAX, | |
409 | processor_walk_namespace_cb, NULL, &action, NULL); | |
410 | } | |
411 | ||
412 | static const struct acpi_device_id processor_device_ids[] = { | |
413 | {ACPI_PROCESSOR_OBJECT_HID, 0}, | |
414 | {ACPI_PROCESSOR_DEVICE_HID, 0}, | |
415 | {"", 0}, | |
416 | }; | |
417 | MODULE_DEVICE_TABLE(acpi, processor_device_ids); | |
418 | ||
419 | static struct acpi_driver xen_acpi_processor_driver = { | |
420 | .name = "processor", | |
421 | .class = ACPI_PROCESSOR_CLASS, | |
422 | .ids = processor_device_ids, | |
423 | .ops = { | |
424 | .add = xen_acpi_processor_add, | |
425 | .remove = xen_acpi_processor_remove, | |
426 | }, | |
427 | }; | |
428 | ||
429 | static int __init xen_acpi_processor_init(void) | |
430 | { | |
431 | int result = 0; | |
432 | ||
433 | if (!xen_initial_domain()) | |
434 | return -ENODEV; | |
435 | ||
436 | /* unregister the stub which only used to reserve driver space */ | |
437 | xen_stub_processor_exit(); | |
438 | ||
439 | result = acpi_bus_register_driver(&xen_acpi_processor_driver); | |
440 | if (result < 0) { | |
441 | xen_stub_processor_init(); | |
442 | return result; | |
443 | } | |
444 | ||
445 | acpi_processor_install_hotplug_notify(); | |
446 | return 0; | |
447 | } | |
448 | ||
449 | static void __exit xen_acpi_processor_exit(void) | |
450 | { | |
451 | if (!xen_initial_domain()) | |
452 | return; | |
453 | ||
454 | acpi_processor_uninstall_hotplug_notify(); | |
455 | ||
456 | acpi_bus_unregister_driver(&xen_acpi_processor_driver); | |
457 | ||
458 | /* | |
459 | * stub reserve space again to prevent any chance of native | |
460 | * driver loading. | |
461 | */ | |
462 | xen_stub_processor_init(); | |
463 | return; | |
464 | } | |
465 | ||
466 | module_init(xen_acpi_processor_init); | |
467 | module_exit(xen_acpi_processor_exit); | |
468 | ACPI_MODULE_NAME("xen-acpi-cpuhotplug"); | |
469 | MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>"); | |
470 | MODULE_DESCRIPTION("Xen Hotplug CPU Driver"); | |
471 | MODULE_LICENSE("GPL"); |