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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 | ||
283c0972 JP |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
39adc483 LJ |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/types.h> | |
24 | #include <linux/cpu.h> | |
25 | #include <linux/acpi.h> | |
26 | #include <linux/uaccess.h> | |
39adc483 | 27 | #include <acpi/processor.h> |
39adc483 LJ |
28 | #include <xen/acpi.h> |
29 | #include <xen/interface/platform.h> | |
30 | #include <asm/xen/hypercall.h> | |
31 | ||
32 | #define PREFIX "ACPI:xen_cpu_hotplug:" | |
33 | ||
34 | #define INSTALL_NOTIFY_HANDLER 0 | |
35 | #define UNINSTALL_NOTIFY_HANDLER 1 | |
36 | ||
37 | static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr); | |
38 | ||
39 | /* -------------------------------------------------------------------------- | |
40 | Driver Interface | |
41 | -------------------------------------------------------------------------- */ | |
42 | ||
43 | static int xen_acpi_processor_enable(struct acpi_device *device) | |
44 | { | |
45 | acpi_status status = 0; | |
46 | unsigned long long value; | |
47 | union acpi_object object = { 0 }; | |
48 | struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; | |
49 | struct acpi_processor *pr; | |
50 | ||
51 | pr = acpi_driver_data(device); | |
52 | if (!pr) { | |
53 | pr_err(PREFIX "Cannot find driver data\n"); | |
54 | return -EINVAL; | |
55 | } | |
56 | ||
57 | if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) { | |
58 | /* Declared with "Processor" statement; match ProcessorID */ | |
59 | status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer); | |
60 | if (ACPI_FAILURE(status)) { | |
61 | pr_err(PREFIX "Evaluating processor object\n"); | |
62 | return -ENODEV; | |
63 | } | |
64 | ||
65 | pr->acpi_id = object.processor.proc_id; | |
66 | } else { | |
67 | /* Declared with "Device" statement; match _UID */ | |
68 | status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID, | |
69 | NULL, &value); | |
70 | if (ACPI_FAILURE(status)) { | |
71 | pr_err(PREFIX "Evaluating processor _UID\n"); | |
72 | return -ENODEV; | |
73 | } | |
74 | ||
75 | pr->acpi_id = value; | |
76 | } | |
77 | ||
78 | pr->id = xen_pcpu_id(pr->acpi_id); | |
79 | ||
80 | if ((int)pr->id < 0) | |
81 | /* This cpu is not presented at hypervisor, try to hotadd it */ | |
82 | if (ACPI_FAILURE(xen_acpi_cpu_hotadd(pr))) { | |
83 | pr_err(PREFIX "Hotadd CPU (acpi_id = %d) failed.\n", | |
84 | pr->acpi_id); | |
85 | return -ENODEV; | |
86 | } | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
a83048eb | 91 | static int xen_acpi_processor_add(struct acpi_device *device) |
39adc483 LJ |
92 | { |
93 | int ret; | |
94 | struct acpi_processor *pr; | |
95 | ||
96 | if (!device) | |
97 | return -EINVAL; | |
98 | ||
99 | pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); | |
100 | if (!pr) | |
101 | return -ENOMEM; | |
102 | ||
103 | pr->handle = device->handle; | |
104 | strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME); | |
105 | strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS); | |
106 | device->driver_data = pr; | |
107 | ||
108 | ret = xen_acpi_processor_enable(device); | |
109 | if (ret) | |
110 | pr_err(PREFIX "Error when enabling Xen processor\n"); | |
111 | ||
112 | return ret; | |
113 | } | |
114 | ||
77be36de | 115 | static int xen_acpi_processor_remove(struct acpi_device *device) |
39adc483 LJ |
116 | { |
117 | struct acpi_processor *pr; | |
118 | ||
119 | if (!device) | |
120 | return -EINVAL; | |
121 | ||
122 | pr = acpi_driver_data(device); | |
123 | if (!pr) | |
124 | return -EINVAL; | |
125 | ||
126 | kfree(pr); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | /*-------------------------------------------------------------- | |
131 | Acpi processor hotplug support | |
132 | --------------------------------------------------------------*/ | |
133 | ||
134 | static int is_processor_present(acpi_handle handle) | |
135 | { | |
136 | acpi_status status; | |
137 | unsigned long long sta = 0; | |
138 | ||
139 | ||
140 | status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); | |
141 | ||
142 | if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT)) | |
143 | return 1; | |
144 | ||
145 | /* | |
146 | * _STA is mandatory for a processor that supports hot plug | |
147 | */ | |
148 | if (status == AE_NOT_FOUND) | |
149 | pr_info(PREFIX "Processor does not support hot plug\n"); | |
150 | else | |
151 | pr_info(PREFIX "Processor Device is not present"); | |
152 | return 0; | |
153 | } | |
154 | ||
155 | static int xen_apic_id(acpi_handle handle) | |
156 | { | |
157 | struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; | |
158 | union acpi_object *obj; | |
159 | struct acpi_madt_local_apic *lapic; | |
160 | int apic_id; | |
161 | ||
162 | if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer))) | |
163 | return -EINVAL; | |
164 | ||
165 | if (!buffer.length || !buffer.pointer) | |
166 | return -EINVAL; | |
167 | ||
168 | obj = buffer.pointer; | |
169 | if (obj->type != ACPI_TYPE_BUFFER || | |
170 | obj->buffer.length < sizeof(*lapic)) { | |
171 | kfree(buffer.pointer); | |
172 | return -EINVAL; | |
173 | } | |
174 | ||
175 | lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer; | |
176 | ||
177 | if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC || | |
178 | !(lapic->lapic_flags & ACPI_MADT_ENABLED)) { | |
179 | kfree(buffer.pointer); | |
180 | return -EINVAL; | |
181 | } | |
182 | ||
183 | apic_id = (uint32_t)lapic->id; | |
184 | kfree(buffer.pointer); | |
185 | buffer.length = ACPI_ALLOCATE_BUFFER; | |
186 | buffer.pointer = NULL; | |
187 | ||
188 | return apic_id; | |
189 | } | |
190 | ||
191 | static int xen_hotadd_cpu(struct acpi_processor *pr) | |
192 | { | |
193 | int cpu_id, apic_id, pxm; | |
194 | struct xen_platform_op op; | |
195 | ||
196 | apic_id = xen_apic_id(pr->handle); | |
197 | if (apic_id < 0) { | |
198 | pr_err(PREFIX "Failed to get apic_id for acpi_id %d\n", | |
199 | pr->acpi_id); | |
200 | return -ENODEV; | |
201 | } | |
202 | ||
203 | pxm = xen_acpi_get_pxm(pr->handle); | |
204 | if (pxm < 0) { | |
205 | pr_err(PREFIX "Failed to get _PXM for acpi_id %d\n", | |
206 | pr->acpi_id); | |
207 | return pxm; | |
208 | } | |
209 | ||
210 | op.cmd = XENPF_cpu_hotadd; | |
211 | op.u.cpu_add.apic_id = apic_id; | |
212 | op.u.cpu_add.acpi_id = pr->acpi_id; | |
213 | op.u.cpu_add.pxm = pxm; | |
214 | ||
215 | cpu_id = HYPERVISOR_dom0_op(&op); | |
216 | if (cpu_id < 0) | |
217 | pr_err(PREFIX "Failed to hotadd CPU for acpi_id %d\n", | |
218 | pr->acpi_id); | |
219 | ||
220 | return cpu_id; | |
221 | } | |
222 | ||
223 | static acpi_status xen_acpi_cpu_hotadd(struct acpi_processor *pr) | |
224 | { | |
225 | if (!is_processor_present(pr->handle)) | |
226 | return AE_ERROR; | |
227 | ||
228 | pr->id = xen_hotadd_cpu(pr); | |
229 | if ((int)pr->id < 0) | |
230 | return AE_ERROR; | |
231 | ||
232 | /* | |
233 | * Sync with Xen hypervisor, providing new /sys/.../xen_cpuX | |
234 | * interface after cpu hotadded. | |
235 | */ | |
236 | xen_pcpu_hotplug_sync(); | |
237 | ||
238 | return AE_OK; | |
239 | } | |
240 | ||
39adc483 LJ |
241 | static int acpi_processor_device_remove(struct acpi_device *device) |
242 | { | |
243 | pr_debug(PREFIX "Xen does not support CPU hotremove\n"); | |
244 | ||
245 | return -ENOSYS; | |
246 | } | |
247 | ||
248 | static void acpi_processor_hotplug_notify(acpi_handle handle, | |
249 | u32 event, void *data) | |
250 | { | |
251 | struct acpi_processor *pr; | |
252 | struct acpi_device *device = NULL; | |
253 | u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */ | |
254 | int result; | |
255 | ||
1b37d6ea LJ |
256 | acpi_scan_lock_acquire(); |
257 | ||
39adc483 LJ |
258 | switch (event) { |
259 | case ACPI_NOTIFY_BUS_CHECK: | |
260 | case ACPI_NOTIFY_DEVICE_CHECK: | |
261 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
262 | "Processor driver received %s event\n", | |
263 | (event == ACPI_NOTIFY_BUS_CHECK) ? | |
264 | "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK")); | |
265 | ||
266 | if (!is_processor_present(handle)) | |
267 | break; | |
268 | ||
202317a5 RW |
269 | acpi_bus_get_device(handle, &device); |
270 | if (acpi_device_enumerated(device)) | |
39adc483 LJ |
271 | break; |
272 | ||
1b37d6ea | 273 | result = acpi_bus_scan(handle); |
39adc483 LJ |
274 | if (result) { |
275 | pr_err(PREFIX "Unable to add the device\n"); | |
276 | break; | |
277 | } | |
202317a5 RW |
278 | device = NULL; |
279 | acpi_bus_get_device(handle, &device); | |
280 | if (!acpi_device_enumerated(device)) { | |
1b37d6ea LJ |
281 | pr_err(PREFIX "Missing device object\n"); |
282 | break; | |
283 | } | |
39adc483 LJ |
284 | ost_code = ACPI_OST_SC_SUCCESS; |
285 | break; | |
286 | ||
287 | case ACPI_NOTIFY_EJECT_REQUEST: | |
288 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
289 | "received ACPI_NOTIFY_EJECT_REQUEST\n")); | |
290 | ||
291 | if (acpi_bus_get_device(handle, &device)) { | |
292 | pr_err(PREFIX "Device don't exist, dropping EJECT\n"); | |
293 | break; | |
294 | } | |
295 | pr = acpi_driver_data(device); | |
296 | if (!pr) { | |
297 | pr_err(PREFIX "Driver data is NULL, dropping EJECT\n"); | |
298 | break; | |
299 | } | |
300 | ||
301 | /* | |
302 | * TBD: implement acpi_processor_device_remove if Xen support | |
303 | * CPU hotremove in the future. | |
304 | */ | |
305 | acpi_processor_device_remove(device); | |
306 | break; | |
307 | ||
308 | default: | |
309 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, | |
310 | "Unsupported event [0x%x]\n", event)); | |
311 | ||
312 | /* non-hotplug event; possibly handled by other handler */ | |
1b37d6ea | 313 | goto out; |
39adc483 LJ |
314 | } |
315 | ||
700b8422 | 316 | (void) acpi_evaluate_ost(handle, event, ost_code, NULL); |
1b37d6ea LJ |
317 | |
318 | out: | |
319 | acpi_scan_lock_release(); | |
39adc483 LJ |
320 | } |
321 | ||
322 | static acpi_status is_processor_device(acpi_handle handle) | |
323 | { | |
324 | struct acpi_device_info *info; | |
325 | char *hid; | |
326 | acpi_status status; | |
327 | ||
328 | status = acpi_get_object_info(handle, &info); | |
329 | if (ACPI_FAILURE(status)) | |
330 | return status; | |
331 | ||
332 | if (info->type == ACPI_TYPE_PROCESSOR) { | |
333 | kfree(info); | |
334 | return AE_OK; /* found a processor object */ | |
335 | } | |
336 | ||
337 | if (!(info->valid & ACPI_VALID_HID)) { | |
338 | kfree(info); | |
339 | return AE_ERROR; | |
340 | } | |
341 | ||
342 | hid = info->hardware_id.string; | |
343 | if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) { | |
344 | kfree(info); | |
345 | return AE_ERROR; | |
346 | } | |
347 | ||
348 | kfree(info); | |
349 | return AE_OK; /* found a processor device object */ | |
350 | } | |
351 | ||
352 | static acpi_status | |
353 | processor_walk_namespace_cb(acpi_handle handle, | |
354 | u32 lvl, void *context, void **rv) | |
355 | { | |
356 | acpi_status status; | |
357 | int *action = context; | |
358 | ||
359 | status = is_processor_device(handle); | |
360 | if (ACPI_FAILURE(status)) | |
361 | return AE_OK; /* not a processor; continue to walk */ | |
362 | ||
363 | switch (*action) { | |
364 | case INSTALL_NOTIFY_HANDLER: | |
365 | acpi_install_notify_handler(handle, | |
366 | ACPI_SYSTEM_NOTIFY, | |
367 | acpi_processor_hotplug_notify, | |
368 | NULL); | |
369 | break; | |
370 | case UNINSTALL_NOTIFY_HANDLER: | |
371 | acpi_remove_notify_handler(handle, | |
372 | ACPI_SYSTEM_NOTIFY, | |
373 | acpi_processor_hotplug_notify); | |
374 | break; | |
375 | default: | |
376 | break; | |
377 | } | |
378 | ||
379 | /* found a processor; skip walking underneath */ | |
380 | return AE_CTRL_DEPTH; | |
381 | } | |
382 | ||
383 | static | |
384 | void acpi_processor_install_hotplug_notify(void) | |
385 | { | |
386 | int action = INSTALL_NOTIFY_HANDLER; | |
387 | acpi_walk_namespace(ACPI_TYPE_ANY, | |
388 | ACPI_ROOT_OBJECT, | |
389 | ACPI_UINT32_MAX, | |
390 | processor_walk_namespace_cb, NULL, &action, NULL); | |
391 | } | |
392 | ||
393 | static | |
394 | void acpi_processor_uninstall_hotplug_notify(void) | |
395 | { | |
396 | int action = UNINSTALL_NOTIFY_HANDLER; | |
397 | acpi_walk_namespace(ACPI_TYPE_ANY, | |
398 | ACPI_ROOT_OBJECT, | |
399 | ACPI_UINT32_MAX, | |
400 | processor_walk_namespace_cb, NULL, &action, NULL); | |
401 | } | |
402 | ||
403 | static const struct acpi_device_id processor_device_ids[] = { | |
404 | {ACPI_PROCESSOR_OBJECT_HID, 0}, | |
405 | {ACPI_PROCESSOR_DEVICE_HID, 0}, | |
406 | {"", 0}, | |
407 | }; | |
408 | MODULE_DEVICE_TABLE(acpi, processor_device_ids); | |
409 | ||
410 | static struct acpi_driver xen_acpi_processor_driver = { | |
411 | .name = "processor", | |
412 | .class = ACPI_PROCESSOR_CLASS, | |
413 | .ids = processor_device_ids, | |
414 | .ops = { | |
415 | .add = xen_acpi_processor_add, | |
416 | .remove = xen_acpi_processor_remove, | |
417 | }, | |
418 | }; | |
419 | ||
420 | static int __init xen_acpi_processor_init(void) | |
421 | { | |
422 | int result = 0; | |
423 | ||
424 | if (!xen_initial_domain()) | |
425 | return -ENODEV; | |
426 | ||
427 | /* unregister the stub which only used to reserve driver space */ | |
428 | xen_stub_processor_exit(); | |
429 | ||
430 | result = acpi_bus_register_driver(&xen_acpi_processor_driver); | |
431 | if (result < 0) { | |
432 | xen_stub_processor_init(); | |
433 | return result; | |
434 | } | |
435 | ||
436 | acpi_processor_install_hotplug_notify(); | |
437 | return 0; | |
438 | } | |
439 | ||
440 | static void __exit xen_acpi_processor_exit(void) | |
441 | { | |
442 | if (!xen_initial_domain()) | |
443 | return; | |
444 | ||
445 | acpi_processor_uninstall_hotplug_notify(); | |
446 | ||
447 | acpi_bus_unregister_driver(&xen_acpi_processor_driver); | |
448 | ||
449 | /* | |
450 | * stub reserve space again to prevent any chance of native | |
451 | * driver loading. | |
452 | */ | |
453 | xen_stub_processor_init(); | |
454 | return; | |
455 | } | |
456 | ||
457 | module_init(xen_acpi_processor_init); | |
458 | module_exit(xen_acpi_processor_exit); | |
459 | ACPI_MODULE_NAME("xen-acpi-cpuhotplug"); | |
460 | MODULE_AUTHOR("Liu Jinsong <jinsong.liu@intel.com>"); | |
461 | MODULE_DESCRIPTION("Xen Hotplug CPU Driver"); | |
462 | MODULE_LICENSE("GPL"); |