Commit | Line | Data |
---|---|---|
f65c9bb3 LJ |
1 | /****************************************************************************** |
2 | * pcpu.c | |
3 | * Management physical cpu in dom0, get pcpu info and provide sys interface | |
4 | * | |
5 | * Copyright (c) 2012 Intel Corporation | |
6 | * Author: Liu, Jinsong <jinsong.liu@intel.com> | |
7 | * Author: Jiang, Yunhong <yunhong.jiang@intel.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License version 2 | |
11 | * as published by the Free Software Foundation; or, when distributed | |
12 | * separately from the Linux kernel or incorporated into other | |
13 | * software packages, subject to the following license: | |
14 | * | |
15 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
16 | * of this source file (the "Software"), to deal in the Software without | |
17 | * restriction, including without limitation the rights to use, copy, modify, | |
18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
19 | * and to permit persons to whom the Software is furnished to do so, subject to | |
20 | * the following conditions: | |
21 | * | |
22 | * The above copyright notice and this permission notice shall be included in | |
23 | * all copies or substantial portions of the Software. | |
24 | * | |
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
31 | * IN THE SOFTWARE. | |
32 | */ | |
33 | ||
283c0972 JP |
34 | #define pr_fmt(fmt) "xen_cpu: " fmt |
35 | ||
f65c9bb3 LJ |
36 | #include <linux/interrupt.h> |
37 | #include <linux/spinlock.h> | |
38 | #include <linux/cpu.h> | |
39 | #include <linux/stat.h> | |
40 | #include <linux/capability.h> | |
41 | ||
42 | #include <xen/xen.h> | |
6cb606f1 | 43 | #include <xen/acpi.h> |
f65c9bb3 LJ |
44 | #include <xen/xenbus.h> |
45 | #include <xen/events.h> | |
46 | #include <xen/interface/platform.h> | |
47 | #include <asm/xen/hypervisor.h> | |
48 | #include <asm/xen/hypercall.h> | |
49 | ||
bfa993b3 RPM |
50 | #ifdef CONFIG_ACPI |
51 | #include <acpi/processor.h> | |
52 | #endif | |
f65c9bb3 LJ |
53 | |
54 | /* | |
55 | * @cpu_id: Xen physical cpu logic number | |
56 | * @flags: Xen physical cpu status flag | |
57 | * - XEN_PCPU_FLAGS_ONLINE: cpu is online | |
58 | * - XEN_PCPU_FLAGS_INVALID: cpu is not present | |
59 | */ | |
60 | struct pcpu { | |
61 | struct list_head list; | |
62 | struct device dev; | |
63 | uint32_t cpu_id; | |
073828e9 | 64 | uint32_t acpi_id; |
f65c9bb3 LJ |
65 | uint32_t flags; |
66 | }; | |
67 | ||
68 | static struct bus_type xen_pcpu_subsys = { | |
69 | .name = "xen_cpu", | |
70 | .dev_name = "xen_cpu", | |
71 | }; | |
72 | ||
73 | static DEFINE_MUTEX(xen_pcpu_lock); | |
74 | ||
75 | static LIST_HEAD(xen_pcpus); | |
76 | ||
77 | static int xen_pcpu_down(uint32_t cpu_id) | |
78 | { | |
79 | struct xen_platform_op op = { | |
80 | .cmd = XENPF_cpu_offline, | |
81 | .interface_version = XENPF_INTERFACE_VERSION, | |
82 | .u.cpu_ol.cpuid = cpu_id, | |
83 | }; | |
84 | ||
cfafae94 | 85 | return HYPERVISOR_platform_op(&op); |
f65c9bb3 LJ |
86 | } |
87 | ||
88 | static int xen_pcpu_up(uint32_t cpu_id) | |
89 | { | |
90 | struct xen_platform_op op = { | |
91 | .cmd = XENPF_cpu_online, | |
92 | .interface_version = XENPF_INTERFACE_VERSION, | |
93 | .u.cpu_ol.cpuid = cpu_id, | |
94 | }; | |
95 | ||
cfafae94 | 96 | return HYPERVISOR_platform_op(&op); |
f65c9bb3 LJ |
97 | } |
98 | ||
20600617 | 99 | static ssize_t online_show(struct device *dev, |
f65c9bb3 LJ |
100 | struct device_attribute *attr, |
101 | char *buf) | |
102 | { | |
103 | struct pcpu *cpu = container_of(dev, struct pcpu, dev); | |
104 | ||
105 | return sprintf(buf, "%u\n", !!(cpu->flags & XEN_PCPU_FLAGS_ONLINE)); | |
106 | } | |
107 | ||
20600617 | 108 | static ssize_t __ref online_store(struct device *dev, |
f65c9bb3 LJ |
109 | struct device_attribute *attr, |
110 | const char *buf, size_t count) | |
111 | { | |
112 | struct pcpu *pcpu = container_of(dev, struct pcpu, dev); | |
113 | unsigned long long val; | |
114 | ssize_t ret; | |
115 | ||
116 | if (!capable(CAP_SYS_ADMIN)) | |
117 | return -EPERM; | |
118 | ||
119 | if (kstrtoull(buf, 0, &val) < 0) | |
120 | return -EINVAL; | |
121 | ||
122 | switch (val) { | |
123 | case 0: | |
124 | ret = xen_pcpu_down(pcpu->cpu_id); | |
125 | break; | |
126 | case 1: | |
127 | ret = xen_pcpu_up(pcpu->cpu_id); | |
128 | break; | |
129 | default: | |
130 | ret = -EINVAL; | |
131 | } | |
132 | ||
133 | if (ret >= 0) | |
134 | ret = count; | |
135 | return ret; | |
136 | } | |
20600617 | 137 | static DEVICE_ATTR_RW(online); |
f65c9bb3 | 138 | |
4644e5ab TI |
139 | static struct attribute *pcpu_dev_attrs[] = { |
140 | &dev_attr_online.attr, | |
141 | NULL | |
142 | }; | |
143 | ||
144 | static umode_t pcpu_dev_is_visible(struct kobject *kobj, | |
145 | struct attribute *attr, int idx) | |
146 | { | |
147 | struct device *dev = kobj_to_dev(kobj); | |
148 | /* | |
149 | * Xen never offline cpu0 due to several restrictions | |
150 | * and assumptions. This basically doesn't add a sys control | |
151 | * to user, one cannot attempt to offline BSP. | |
152 | */ | |
153 | return dev->id ? attr->mode : 0; | |
154 | } | |
155 | ||
156 | static const struct attribute_group pcpu_dev_group = { | |
157 | .attrs = pcpu_dev_attrs, | |
158 | .is_visible = pcpu_dev_is_visible, | |
159 | }; | |
160 | ||
161 | static const struct attribute_group *pcpu_dev_groups[] = { | |
162 | &pcpu_dev_group, | |
163 | NULL | |
164 | }; | |
165 | ||
f65c9bb3 LJ |
166 | static bool xen_pcpu_online(uint32_t flags) |
167 | { | |
168 | return !!(flags & XEN_PCPU_FLAGS_ONLINE); | |
169 | } | |
170 | ||
171 | static void pcpu_online_status(struct xenpf_pcpuinfo *info, | |
172 | struct pcpu *pcpu) | |
173 | { | |
174 | if (xen_pcpu_online(info->flags) && | |
175 | !xen_pcpu_online(pcpu->flags)) { | |
176 | /* the pcpu is onlined */ | |
177 | pcpu->flags |= XEN_PCPU_FLAGS_ONLINE; | |
178 | kobject_uevent(&pcpu->dev.kobj, KOBJ_ONLINE); | |
179 | } else if (!xen_pcpu_online(info->flags) && | |
180 | xen_pcpu_online(pcpu->flags)) { | |
181 | /* The pcpu is offlined */ | |
182 | pcpu->flags &= ~XEN_PCPU_FLAGS_ONLINE; | |
183 | kobject_uevent(&pcpu->dev.kobj, KOBJ_OFFLINE); | |
184 | } | |
185 | } | |
186 | ||
187 | static struct pcpu *get_pcpu(uint32_t cpu_id) | |
188 | { | |
189 | struct pcpu *pcpu; | |
190 | ||
191 | list_for_each_entry(pcpu, &xen_pcpus, list) { | |
192 | if (pcpu->cpu_id == cpu_id) | |
193 | return pcpu; | |
194 | } | |
195 | ||
196 | return NULL; | |
197 | } | |
198 | ||
199 | static void pcpu_release(struct device *dev) | |
200 | { | |
201 | struct pcpu *pcpu = container_of(dev, struct pcpu, dev); | |
202 | ||
203 | list_del(&pcpu->list); | |
204 | kfree(pcpu); | |
205 | } | |
206 | ||
207 | static void unregister_and_remove_pcpu(struct pcpu *pcpu) | |
208 | { | |
209 | struct device *dev; | |
210 | ||
211 | if (!pcpu) | |
212 | return; | |
213 | ||
214 | dev = &pcpu->dev; | |
f65c9bb3 LJ |
215 | /* pcpu remove would be implicitly done */ |
216 | device_unregister(dev); | |
217 | } | |
218 | ||
219 | static int register_pcpu(struct pcpu *pcpu) | |
220 | { | |
221 | struct device *dev; | |
222 | int err = -EINVAL; | |
223 | ||
224 | if (!pcpu) | |
225 | return err; | |
226 | ||
227 | dev = &pcpu->dev; | |
228 | dev->bus = &xen_pcpu_subsys; | |
229 | dev->id = pcpu->cpu_id; | |
230 | dev->release = pcpu_release; | |
4644e5ab | 231 | dev->groups = pcpu_dev_groups; |
f65c9bb3 LJ |
232 | |
233 | err = device_register(dev); | |
234 | if (err) { | |
da36a2a7 | 235 | put_device(dev); |
f65c9bb3 LJ |
236 | return err; |
237 | } | |
238 | ||
f65c9bb3 LJ |
239 | return 0; |
240 | } | |
241 | ||
242 | static struct pcpu *create_and_register_pcpu(struct xenpf_pcpuinfo *info) | |
243 | { | |
244 | struct pcpu *pcpu; | |
245 | int err; | |
246 | ||
247 | if (info->flags & XEN_PCPU_FLAGS_INVALID) | |
248 | return ERR_PTR(-ENODEV); | |
249 | ||
250 | pcpu = kzalloc(sizeof(struct pcpu), GFP_KERNEL); | |
251 | if (!pcpu) | |
252 | return ERR_PTR(-ENOMEM); | |
253 | ||
254 | INIT_LIST_HEAD(&pcpu->list); | |
255 | pcpu->cpu_id = info->xen_cpuid; | |
073828e9 | 256 | pcpu->acpi_id = info->acpi_id; |
f65c9bb3 LJ |
257 | pcpu->flags = info->flags; |
258 | ||
259 | /* Need hold on xen_pcpu_lock before pcpu list manipulations */ | |
260 | list_add_tail(&pcpu->list, &xen_pcpus); | |
261 | ||
262 | err = register_pcpu(pcpu); | |
263 | if (err) { | |
283c0972 | 264 | pr_warn("Failed to register pcpu%u\n", info->xen_cpuid); |
f65c9bb3 LJ |
265 | return ERR_PTR(-ENOENT); |
266 | } | |
267 | ||
268 | return pcpu; | |
269 | } | |
270 | ||
271 | /* | |
272 | * Caller should hold the xen_pcpu_lock | |
273 | */ | |
274 | static int sync_pcpu(uint32_t cpu, uint32_t *max_cpu) | |
275 | { | |
276 | int ret; | |
277 | struct pcpu *pcpu = NULL; | |
278 | struct xenpf_pcpuinfo *info; | |
279 | struct xen_platform_op op = { | |
280 | .cmd = XENPF_get_cpuinfo, | |
281 | .interface_version = XENPF_INTERFACE_VERSION, | |
282 | .u.pcpu_info.xen_cpuid = cpu, | |
283 | }; | |
284 | ||
cfafae94 | 285 | ret = HYPERVISOR_platform_op(&op); |
f65c9bb3 LJ |
286 | if (ret) |
287 | return ret; | |
288 | ||
289 | info = &op.u.pcpu_info; | |
290 | if (max_cpu) | |
291 | *max_cpu = info->max_present; | |
292 | ||
293 | pcpu = get_pcpu(cpu); | |
294 | ||
295 | /* | |
296 | * Only those at cpu present map has its sys interface. | |
297 | */ | |
298 | if (info->flags & XEN_PCPU_FLAGS_INVALID) { | |
4f8c8527 | 299 | unregister_and_remove_pcpu(pcpu); |
f65c9bb3 LJ |
300 | return 0; |
301 | } | |
302 | ||
303 | if (!pcpu) { | |
304 | pcpu = create_and_register_pcpu(info); | |
305 | if (IS_ERR_OR_NULL(pcpu)) | |
306 | return -ENODEV; | |
307 | } else | |
308 | pcpu_online_status(info, pcpu); | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | /* | |
314 | * Sync dom0's pcpu information with xen hypervisor's | |
315 | */ | |
316 | static int xen_sync_pcpus(void) | |
317 | { | |
318 | /* | |
319 | * Boot cpu always have cpu_id 0 in xen | |
320 | */ | |
321 | uint32_t cpu = 0, max_cpu = 0; | |
322 | int err = 0; | |
323 | struct pcpu *pcpu, *tmp; | |
324 | ||
325 | mutex_lock(&xen_pcpu_lock); | |
326 | ||
327 | while (!err && (cpu <= max_cpu)) { | |
328 | err = sync_pcpu(cpu, &max_cpu); | |
329 | cpu++; | |
330 | } | |
331 | ||
332 | if (err) | |
333 | list_for_each_entry_safe(pcpu, tmp, &xen_pcpus, list) | |
334 | unregister_and_remove_pcpu(pcpu); | |
335 | ||
336 | mutex_unlock(&xen_pcpu_lock); | |
337 | ||
338 | return err; | |
339 | } | |
340 | ||
341 | static void xen_pcpu_work_fn(struct work_struct *work) | |
342 | { | |
343 | xen_sync_pcpus(); | |
344 | } | |
345 | static DECLARE_WORK(xen_pcpu_work, xen_pcpu_work_fn); | |
346 | ||
347 | static irqreturn_t xen_pcpu_interrupt(int irq, void *dev_id) | |
348 | { | |
349 | schedule_work(&xen_pcpu_work); | |
350 | return IRQ_HANDLED; | |
351 | } | |
352 | ||
353 | static int __init xen_pcpu_init(void) | |
354 | { | |
355 | int irq, ret; | |
356 | ||
357 | if (!xen_initial_domain()) | |
358 | return -ENODEV; | |
359 | ||
360 | irq = bind_virq_to_irqhandler(VIRQ_PCPU_STATE, 0, | |
361 | xen_pcpu_interrupt, 0, | |
362 | "xen-pcpu", NULL); | |
363 | if (irq < 0) { | |
283c0972 | 364 | pr_warn("Failed to bind pcpu virq\n"); |
f65c9bb3 LJ |
365 | return irq; |
366 | } | |
367 | ||
368 | ret = subsys_system_register(&xen_pcpu_subsys, NULL); | |
369 | if (ret) { | |
283c0972 | 370 | pr_warn("Failed to register pcpu subsys\n"); |
f65c9bb3 LJ |
371 | goto err1; |
372 | } | |
373 | ||
374 | ret = xen_sync_pcpus(); | |
375 | if (ret) { | |
283c0972 | 376 | pr_warn("Failed to sync pcpu info\n"); |
f65c9bb3 LJ |
377 | goto err2; |
378 | } | |
379 | ||
380 | return 0; | |
381 | ||
382 | err2: | |
383 | bus_unregister(&xen_pcpu_subsys); | |
384 | err1: | |
385 | unbind_from_irqhandler(irq, NULL); | |
386 | return ret; | |
387 | } | |
388 | arch_initcall(xen_pcpu_init); | |
073828e9 RPM |
389 | |
390 | #ifdef CONFIG_ACPI | |
391 | bool __init xen_processor_present(uint32_t acpi_id) | |
392 | { | |
393 | const struct pcpu *pcpu; | |
394 | bool online = false; | |
395 | ||
396 | mutex_lock(&xen_pcpu_lock); | |
397 | list_for_each_entry(pcpu, &xen_pcpus, list) | |
398 | if (pcpu->acpi_id == acpi_id) { | |
399 | online = pcpu->flags & XEN_PCPU_FLAGS_ONLINE; | |
400 | break; | |
401 | } | |
402 | mutex_unlock(&xen_pcpu_lock); | |
403 | ||
404 | return online; | |
405 | } | |
bfa993b3 RPM |
406 | |
407 | void xen_sanitize_proc_cap_bits(uint32_t *cap) | |
408 | { | |
409 | struct xen_platform_op op = { | |
410 | .cmd = XENPF_set_processor_pminfo, | |
411 | .u.set_pminfo.id = -1, | |
412 | .u.set_pminfo.type = XEN_PM_PDC, | |
413 | }; | |
414 | u32 buf[3] = { ACPI_PDC_REVISION_ID, 1, *cap }; | |
415 | int ret; | |
416 | ||
417 | set_xen_guest_handle(op.u.set_pminfo.pdc, buf); | |
418 | ret = HYPERVISOR_platform_op(&op); | |
419 | if (ret) | |
420 | pr_err("sanitize of _PDC buffer bits from Xen failed: %d\n", | |
421 | ret); | |
422 | else | |
423 | *cap = buf[2]; | |
424 | } | |
073828e9 | 425 | #endif |