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