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1/*
2 * Copyright 2012 by Oracle Inc
3 * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
4 *
5 * This code borrows ideas from https://lkml.org/lkml/2011/11/30/249
6 * so many thanks go to Kevin Tian <kevin.tian@intel.com>
7 * and Yu Ke <ke.yu@intel.com>.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms and conditions of the GNU General Public License,
11 * version 2, as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * more details.
17 *
18 */
19
20#include <linux/cpumask.h>
21#include <linux/cpufreq.h>
22#include <linux/freezer.h>
23#include <linux/kernel.h>
24#include <linux/kthread.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/types.h>
28#include <acpi/acpi_bus.h>
29#include <acpi/acpi_drivers.h>
30#include <acpi/processor.h>
31
32#include <xen/xen.h>
33#include <xen/interface/platform.h>
34#include <asm/xen/hypercall.h>
35
36#define DRV_NAME "xen-acpi-processor: "
37
38static int no_hypercall;
39MODULE_PARM_DESC(off, "Inhibit the hypercall.");
40module_param_named(off, no_hypercall, int, 0400);
41
42/*
43 * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit
44 * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which
45 * can be less than what we want to put in. Instead use the 'nr_acpi_bits'
46 * which is dynamically computed based on the MADT or x2APIC table.
47 */
48static unsigned int nr_acpi_bits;
49/* Mutex to protect the acpi_ids_done - for CPU hotplug use. */
50static DEFINE_MUTEX(acpi_ids_mutex);
51/* Which ACPI ID we have processed from 'struct acpi_processor'. */
52static unsigned long *acpi_ids_done;
53/* Which ACPI ID exist in the SSDT/DSDT processor definitions. */
54static unsigned long __initdata *acpi_id_present;
55/* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
56static unsigned long __initdata *acpi_id_cst_present;
57
58static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
59{
60 struct xen_platform_op op = {
61 .cmd = XENPF_set_processor_pminfo,
62 .interface_version = XENPF_INTERFACE_VERSION,
63 .u.set_pminfo.id = _pr->acpi_id,
64 .u.set_pminfo.type = XEN_PM_CX,
65 };
66 struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
67 struct acpi_processor_cx *cx;
68 unsigned int i, ok;
69 int ret = 0;
70
71 dst_cx_states = kcalloc(_pr->power.count,
72 sizeof(struct xen_processor_cx), GFP_KERNEL);
73 if (!dst_cx_states)
74 return -ENOMEM;
75
76 for (ok = 0, i = 1; i <= _pr->power.count; i++) {
77 cx = &_pr->power.states[i];
78 if (!cx->valid)
79 continue;
80
81 dst_cx = &(dst_cx_states[ok++]);
82
83 dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
84 if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
85 dst_cx->reg.bit_width = 8;
86 dst_cx->reg.bit_offset = 0;
87 dst_cx->reg.access_size = 1;
88 } else {
89 dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
90 if (cx->entry_method == ACPI_CSTATE_FFH) {
91 /* NATIVE_CSTATE_BEYOND_HALT */
92 dst_cx->reg.bit_offset = 2;
93 dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
94 }
95 dst_cx->reg.access_size = 0;
96 }
97 dst_cx->reg.address = cx->address;
98
99 dst_cx->type = cx->type;
100 dst_cx->latency = cx->latency;
101 dst_cx->power = cx->power;
102
103 dst_cx->dpcnt = 0;
104 set_xen_guest_handle(dst_cx->dp, NULL);
105 }
106 if (!ok) {
107 pr_debug(DRV_NAME "No _Cx for ACPI CPU %u\n", _pr->acpi_id);
108 kfree(dst_cx_states);
109 return -EINVAL;
110 }
111 op.u.set_pminfo.power.count = ok;
112 op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
113 op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
114 op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
115 op.u.set_pminfo.power.flags.power_setup_done =
116 _pr->flags.power_setup_done;
117
118 set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);
119
120 if (!no_hypercall)
121 ret = HYPERVISOR_dom0_op(&op);
122
123 if (!ret) {
124 pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id);
125 for (i = 1; i <= _pr->power.count; i++) {
126 cx = &_pr->power.states[i];
127 if (!cx->valid)
128 continue;
129 pr_debug(" C%d: %s %d uS\n",
130 cx->type, cx->desc, (u32)cx->latency);
131 }
132 } else if (ret != -EINVAL)
133 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
134 * table is referencing a non-existing CPU - which can happen
135 * with broken ACPI tables. */
136 pr_err(DRV_NAME "(CX): Hypervisor error (%d) for ACPI CPU%u\n",
137 ret, _pr->acpi_id);
138
139 kfree(dst_cx_states);
140
141 return ret;
142}
143static struct xen_processor_px *
144xen_copy_pss_data(struct acpi_processor *_pr,
145 struct xen_processor_performance *dst_perf)
146{
147 struct xen_processor_px *dst_states = NULL;
148 unsigned int i;
149
150 BUILD_BUG_ON(sizeof(struct xen_processor_px) !=
151 sizeof(struct acpi_processor_px));
152
153 dst_states = kcalloc(_pr->performance->state_count,
154 sizeof(struct xen_processor_px), GFP_KERNEL);
155 if (!dst_states)
156 return ERR_PTR(-ENOMEM);
157
158 dst_perf->state_count = _pr->performance->state_count;
159 for (i = 0; i < _pr->performance->state_count; i++) {
160 /* Fortunatly for us, they are both the same size */
161 memcpy(&(dst_states[i]), &(_pr->performance->states[i]),
162 sizeof(struct acpi_processor_px));
163 }
164 return dst_states;
165}
166static int xen_copy_psd_data(struct acpi_processor *_pr,
167 struct xen_processor_performance *dst)
168{
169 struct acpi_psd_package *pdomain;
170
171 BUILD_BUG_ON(sizeof(struct xen_psd_package) !=
172 sizeof(struct acpi_psd_package));
173
174 /* This information is enumerated only if acpi_processor_preregister_performance
175 * has been called.
176 */
177 dst->shared_type = _pr->performance->shared_type;
178
179 pdomain = &(_pr->performance->domain_info);
180
181 /* 'acpi_processor_preregister_performance' does not parse if the
182 * num_processors <= 1, but Xen still requires it. Do it manually here.
183 */
184 if (pdomain->num_processors <= 1) {
185 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
186 dst->shared_type = CPUFREQ_SHARED_TYPE_ALL;
187 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
188 dst->shared_type = CPUFREQ_SHARED_TYPE_HW;
189 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
190 dst->shared_type = CPUFREQ_SHARED_TYPE_ANY;
191
192 }
193 memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package));
194 return 0;
195}
196static int xen_copy_pct_data(struct acpi_pct_register *pct,
197 struct xen_pct_register *dst_pct)
198{
199 /* It would be nice if you could just do 'memcpy(pct, dst_pct') but
200 * sadly the Xen structure did not have the proper padding so the
201 * descriptor field takes two (dst_pct) bytes instead of one (pct).
202 */
203 dst_pct->descriptor = pct->descriptor;
204 dst_pct->length = pct->length;
205 dst_pct->space_id = pct->space_id;
206 dst_pct->bit_width = pct->bit_width;
207 dst_pct->bit_offset = pct->bit_offset;
208 dst_pct->reserved = pct->reserved;
209 dst_pct->address = pct->address;
210 return 0;
211}
212static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
213{
214 int ret = 0;
215 struct xen_platform_op op = {
216 .cmd = XENPF_set_processor_pminfo,
217 .interface_version = XENPF_INTERFACE_VERSION,
218 .u.set_pminfo.id = _pr->acpi_id,
219 .u.set_pminfo.type = XEN_PM_PX,
220 };
221 struct xen_processor_performance *dst_perf;
222 struct xen_processor_px *dst_states = NULL;
223
224 dst_perf = &op.u.set_pminfo.perf;
225
226 dst_perf->platform_limit = _pr->performance_platform_limit;
227 dst_perf->flags |= XEN_PX_PPC;
228 xen_copy_pct_data(&(_pr->performance->control_register),
229 &dst_perf->control_register);
230 xen_copy_pct_data(&(_pr->performance->status_register),
231 &dst_perf->status_register);
232 dst_perf->flags |= XEN_PX_PCT;
233 dst_states = xen_copy_pss_data(_pr, dst_perf);
234 if (!IS_ERR_OR_NULL(dst_states)) {
235 set_xen_guest_handle(dst_perf->states, dst_states);
236 dst_perf->flags |= XEN_PX_PSS;
237 }
238 if (!xen_copy_psd_data(_pr, dst_perf))
239 dst_perf->flags |= XEN_PX_PSD;
240
241 if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) {
242 pr_warn(DRV_NAME "ACPI CPU%u missing some P-state data (%x), skipping.\n",
243 _pr->acpi_id, dst_perf->flags);
244 ret = -ENODEV;
245 goto err_free;
246 }
247
248 if (!no_hypercall)
249 ret = HYPERVISOR_dom0_op(&op);
250
251 if (!ret) {
252 struct acpi_processor_performance *perf;
253 unsigned int i;
254
255 perf = _pr->performance;
256 pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id);
257 for (i = 0; i < perf->state_count; i++) {
258 pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n",
259 (i == perf->state ? '*' : ' '), i,
260 (u32) perf->states[i].core_frequency,
261 (u32) perf->states[i].power,
262 (u32) perf->states[i].transition_latency);
263 }
264 } else if (ret != -EINVAL)
265 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
266 * table is referencing a non-existing CPU - which can happen
267 * with broken ACPI tables. */
268 pr_warn(DRV_NAME "(_PXX): Hypervisor error (%d) for ACPI CPU%u\n",
269 ret, _pr->acpi_id);
270err_free:
271 if (!IS_ERR_OR_NULL(dst_states))
272 kfree(dst_states);
273
274 return ret;
275}
276static int upload_pm_data(struct acpi_processor *_pr)
277{
278 int err = 0;
279
280 mutex_lock(&acpi_ids_mutex);
281 if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) {
282 mutex_unlock(&acpi_ids_mutex);
283 return -EBUSY;
284 }
285 if (_pr->flags.power)
286 err = push_cxx_to_hypervisor(_pr);
287
288 if (_pr->performance && _pr->performance->states)
289 err |= push_pxx_to_hypervisor(_pr);
290
291 mutex_unlock(&acpi_ids_mutex);
292 return err;
293}
294static unsigned int __init get_max_acpi_id(void)
295{
296 struct xenpf_pcpuinfo *info;
297 struct xen_platform_op op = {
298 .cmd = XENPF_get_cpuinfo,
299 .interface_version = XENPF_INTERFACE_VERSION,
300 };
301 int ret = 0;
302 unsigned int i, last_cpu, max_acpi_id = 0;
303
304 info = &op.u.pcpu_info;
305 info->xen_cpuid = 0;
306
307 ret = HYPERVISOR_dom0_op(&op);
308 if (ret)
309 return NR_CPUS;
310
311 /* The max_present is the same irregardless of the xen_cpuid */
312 last_cpu = op.u.pcpu_info.max_present;
313 for (i = 0; i <= last_cpu; i++) {
314 info->xen_cpuid = i;
315 ret = HYPERVISOR_dom0_op(&op);
316 if (ret)
317 continue;
318 max_acpi_id = max(info->acpi_id, max_acpi_id);
319 }
320 max_acpi_id *= 2; /* Slack for CPU hotplug support. */
321 pr_debug(DRV_NAME "Max ACPI ID: %u\n", max_acpi_id);
322 return max_acpi_id;
323}
324/*
325 * The read_acpi_id and check_acpi_ids are there to support the Xen
326 * oddity of virtual CPUs != physical CPUs in the initial domain.
327 * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line
328 * which will band the amount of CPUs the initial domain can see.
329 * In general that is OK, except it plays havoc with any of the
330 * for_each_[present|online]_cpu macros which are banded to the virtual
331 * CPU amount.
332 */
333static acpi_status __init
334read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
335{
336 u32 acpi_id;
337 acpi_status status;
338 acpi_object_type acpi_type;
339 unsigned long long tmp;
340 union acpi_object object = { 0 };
341 struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
342 acpi_io_address pblk = 0;
343
344 status = acpi_get_type(handle, &acpi_type);
345 if (ACPI_FAILURE(status))
346 return AE_OK;
347
348 switch (acpi_type) {
349 case ACPI_TYPE_PROCESSOR:
350 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
351 if (ACPI_FAILURE(status))
352 return AE_OK;
353 acpi_id = object.processor.proc_id;
354 pblk = object.processor.pblk_address;
355 break;
356 case ACPI_TYPE_DEVICE:
357 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
358 if (ACPI_FAILURE(status))
359 return AE_OK;
360 acpi_id = tmp;
361 break;
362 default:
363 return AE_OK;
364 }
365 /* There are more ACPI Processor objects than in x2APIC or MADT.
366 * This can happen with incorrect ACPI SSDT declerations. */
367 if (acpi_id > nr_acpi_bits) {
368 pr_debug(DRV_NAME "We only have %u, trying to set %u\n",
369 nr_acpi_bits, acpi_id);
370 return AE_OK;
371 }
372 /* OK, There is a ACPI Processor object */
373 __set_bit(acpi_id, acpi_id_present);
374
375 pr_debug(DRV_NAME "ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id,
376 (unsigned long)pblk);
377
378 status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
379 if (ACPI_FAILURE(status)) {
380 if (!pblk)
381 return AE_OK;
382 }
383 /* .. and it has a C-state */
384 __set_bit(acpi_id, acpi_id_cst_present);
385
386 return AE_OK;
387}
388static int __init check_acpi_ids(struct acpi_processor *pr_backup)
389{
390
391 if (!pr_backup)
392 return -ENODEV;
393
394 /* All online CPUs have been processed at this stage. Now verify
395 * whether in fact "online CPUs" == physical CPUs.
396 */
397 acpi_id_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
398 if (!acpi_id_present)
399 return -ENOMEM;
400
401 acpi_id_cst_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
402 if (!acpi_id_cst_present) {
403 kfree(acpi_id_present);
404 return -ENOMEM;
405 }
406
407 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
408 ACPI_UINT32_MAX,
409 read_acpi_id, NULL, NULL, NULL);
410 acpi_get_devices("ACPI0007", read_acpi_id, NULL, NULL);
411
412 if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) {
413 unsigned int i;
414 for_each_set_bit(i, acpi_id_present, nr_acpi_bits) {
415 pr_backup->acpi_id = i;
416 /* Mask out C-states if there are no _CST or PBLK */
417 pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
418 (void)upload_pm_data(pr_backup);
419 }
420 }
421 kfree(acpi_id_present);
422 acpi_id_present = NULL;
423 kfree(acpi_id_cst_present);
424 acpi_id_cst_present = NULL;
425 return 0;
426}
427static int __init check_prereq(void)
428{
429 struct cpuinfo_x86 *c = &cpu_data(0);
430
431 if (!xen_initial_domain())
432 return -ENODEV;
433
434 if (!acpi_gbl_FADT.smi_command)
435 return -ENODEV;
436
437 if (c->x86_vendor == X86_VENDOR_INTEL) {
438 if (!cpu_has(c, X86_FEATURE_EST))
439 return -ENODEV;
440
441 return 0;
442 }
443 if (c->x86_vendor == X86_VENDOR_AMD) {
444 /* Copied from powernow-k8.h, can't include ../cpufreq/powernow
445 * as we get compile warnings for the static functions.
446 */
447#define CPUID_FREQ_VOLT_CAPABILITIES 0x80000007
448#define USE_HW_PSTATE 0x00000080
449 u32 eax, ebx, ecx, edx;
450 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
451 if ((edx & USE_HW_PSTATE) != USE_HW_PSTATE)
452 return -ENODEV;
453 return 0;
454 }
455 return -ENODEV;
456}
457/* acpi_perf_data is a pointer to percpu data. */
458static struct acpi_processor_performance __percpu *acpi_perf_data;
459
460static void free_acpi_perf_data(void)
461{
462 unsigned int i;
463
464 /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
465 for_each_possible_cpu(i)
466 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
467 ->shared_cpu_map);
468 free_percpu(acpi_perf_data);
469}
470
471static int __init xen_acpi_processor_init(void)
472{
473 struct acpi_processor *pr_backup = NULL;
474 unsigned int i;
475 int rc = check_prereq();
476
477 if (rc)
478 return rc;
479
480 nr_acpi_bits = get_max_acpi_id() + 1;
481 acpi_ids_done = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
482 if (!acpi_ids_done)
483 return -ENOMEM;
484
485 acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
486 if (!acpi_perf_data) {
487 pr_debug(DRV_NAME "Memory allocation error for acpi_perf_data.\n");
488 kfree(acpi_ids_done);
489 return -ENOMEM;
490 }
491 for_each_possible_cpu(i) {
492 if (!zalloc_cpumask_var_node(
493 &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
494 GFP_KERNEL, cpu_to_node(i))) {
495 rc = -ENOMEM;
496 goto err_out;
497 }
498 }
499
500 /* Do initialization in ACPI core. It is OK to fail here. */
501 (void)acpi_processor_preregister_performance(acpi_perf_data);
502
503 for_each_possible_cpu(i) {
504 struct acpi_processor_performance *perf;
505
506 perf = per_cpu_ptr(acpi_perf_data, i);
507 rc = acpi_processor_register_performance(perf, i);
508 if (rc)
509 goto err_out;
510 }
511 rc = acpi_processor_notify_smm(THIS_MODULE);
512 if (rc)
513 goto err_unregister;
514
515 for_each_possible_cpu(i) {
516 struct acpi_processor *_pr;
517 _pr = per_cpu(processors, i /* APIC ID */);
518 if (!_pr)
519 continue;
520
521 if (!pr_backup) {
522 pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
523 memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
524 }
525 (void)upload_pm_data(_pr);
526 }
527 rc = check_acpi_ids(pr_backup);
528 if (rc)
529 goto err_unregister;
530
531 kfree(pr_backup);
532
533 return 0;
534err_unregister:
535 for_each_possible_cpu(i) {
536 struct acpi_processor_performance *perf;
537 perf = per_cpu_ptr(acpi_perf_data, i);
538 acpi_processor_unregister_performance(perf, i);
539 }
540err_out:
541 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
542 free_acpi_perf_data();
543 kfree(acpi_ids_done);
544 return rc;
545}
546static void __exit xen_acpi_processor_exit(void)
547{
548 int i;
549
550 kfree(acpi_ids_done);
551 for_each_possible_cpu(i) {
552 struct acpi_processor_performance *perf;
553 perf = per_cpu_ptr(acpi_perf_data, i);
554 acpi_processor_unregister_performance(perf, i);
555 }
556 free_acpi_perf_data();
557}
558
559MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
560MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
561MODULE_LICENSE("GPL");
562
563/* We want to be loaded before the CPU freq scaling drivers are loaded.
564 * They are loaded in late_initcall. */
565device_initcall(xen_acpi_processor_init);
566module_exit(xen_acpi_processor_exit);