linux/drivers/xen/xen-acpi-processor.c
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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22#include <linux/cpumask.h>
  23#include <linux/cpufreq.h>
  24#include <linux/freezer.h>
  25#include <linux/kernel.h>
  26#include <linux/kthread.h>
  27#include <linux/init.h>
  28#include <linux/module.h>
  29#include <linux/types.h>
  30#include <linux/syscore_ops.h>
  31#include <linux/acpi.h>
  32#include <acpi/processor.h>
  33#include <xen/xen.h>
  34#include <xen/interface/platform.h>
  35#include <asm/xen/hypercall.h>
  36
  37static int no_hypercall;
  38MODULE_PARM_DESC(off, "Inhibit the hypercall.");
  39module_param_named(off, no_hypercall, int, 0400);
  40
  41/*
  42 * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit
  43 * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which
  44 * can be less than what we want to put in. Instead use the 'nr_acpi_bits'
  45 * which is dynamically computed based on the MADT or x2APIC table.
  46 */
  47static unsigned int nr_acpi_bits;
  48/* Mutex to protect the acpi_ids_done - for CPU hotplug use. */
  49static DEFINE_MUTEX(acpi_ids_mutex);
  50/* Which ACPI ID we have processed from 'struct acpi_processor'. */
  51static unsigned long *acpi_ids_done;
  52/* Which ACPI ID exist in the SSDT/DSDT processor definitions. */
  53static unsigned long *acpi_id_present;
  54/* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
  55static unsigned long *acpi_id_cst_present;
  56/* Which ACPI P-State dependencies for a enumerated processor */
  57static struct acpi_psd_package *acpi_psd;
  58
  59static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
  60{
  61        struct xen_platform_op op = {
  62                .cmd                    = XENPF_set_processor_pminfo,
  63                .interface_version      = XENPF_INTERFACE_VERSION,
  64                .u.set_pminfo.id        = _pr->acpi_id,
  65                .u.set_pminfo.type      = XEN_PM_CX,
  66        };
  67        struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
  68        struct acpi_processor_cx *cx;
  69        unsigned int i, ok;
  70        int ret = 0;
  71
  72        dst_cx_states = kcalloc(_pr->power.count,
  73                                sizeof(struct xen_processor_cx), GFP_KERNEL);
  74        if (!dst_cx_states)
  75                return -ENOMEM;
  76
  77        for (ok = 0, i = 1; i <= _pr->power.count; i++) {
  78                cx = &_pr->power.states[i];
  79                if (!cx->valid)
  80                        continue;
  81
  82                dst_cx = &(dst_cx_states[ok++]);
  83
  84                dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
  85                if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
  86                        dst_cx->reg.bit_width = 8;
  87                        dst_cx->reg.bit_offset = 0;
  88                        dst_cx->reg.access_size = 1;
  89                } else {
  90                        dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
  91                        if (cx->entry_method == ACPI_CSTATE_FFH) {
  92                                /* NATIVE_CSTATE_BEYOND_HALT */
  93                                dst_cx->reg.bit_offset = 2;
  94                                dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
  95                        }
  96                        dst_cx->reg.access_size = 0;
  97                }
  98                dst_cx->reg.address = cx->address;
  99
 100                dst_cx->type = cx->type;
 101                dst_cx->latency = cx->latency;
 102
 103                dst_cx->dpcnt = 0;
 104                set_xen_guest_handle(dst_cx->dp, NULL);
 105        }
 106        if (!ok) {
 107                pr_debug("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_platform_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) && (ret != -ENOSYS))
 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("(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("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_platform_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) && (ret != -ENOSYS))
 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("(_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_platform_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_platform_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("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
 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        if (invalid_phys_cpuid(acpi_get_phys_id(handle,
 366                                                acpi_type == ACPI_TYPE_DEVICE,
 367                                                acpi_id))) {
 368                pr_debug("CPU with ACPI ID %u is unavailable\n", acpi_id);
 369                return AE_OK;
 370        }
 371        /* There are more ACPI Processor objects than in x2APIC or MADT.
 372         * This can happen with incorrect ACPI SSDT declerations. */
 373        if (acpi_id >= nr_acpi_bits) {
 374                pr_debug("max acpi id %u, trying to set %u\n",
 375                         nr_acpi_bits - 1, acpi_id);
 376                return AE_OK;
 377        }
 378        /* OK, There is a ACPI Processor object */
 379        __set_bit(acpi_id, acpi_id_present);
 380
 381        pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
 382
 383        /* It has P-state dependencies */
 384        if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) {
 385                pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n",
 386                         acpi_id, acpi_psd[acpi_id].coord_type,
 387                         acpi_psd[acpi_id].domain);
 388        }
 389
 390        status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 391        if (ACPI_FAILURE(status)) {
 392                if (!pblk)
 393                        return AE_OK;
 394        }
 395        /* .. and it has a C-state */
 396        __set_bit(acpi_id, acpi_id_cst_present);
 397
 398        return AE_OK;
 399}
 400static int check_acpi_ids(struct acpi_processor *pr_backup)
 401{
 402
 403        if (!pr_backup)
 404                return -ENODEV;
 405
 406        if (acpi_id_present && acpi_id_cst_present)
 407                /* OK, done this once .. skip to uploading */
 408                goto upload;
 409
 410        /* All online CPUs have been processed at this stage. Now verify
 411         * whether in fact "online CPUs" == physical CPUs.
 412         */
 413        acpi_id_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
 414        if (!acpi_id_present)
 415                return -ENOMEM;
 416
 417        acpi_id_cst_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
 418        if (!acpi_id_cst_present) {
 419                kfree(acpi_id_present);
 420                return -ENOMEM;
 421        }
 422
 423        acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package),
 424                           GFP_KERNEL);
 425        if (!acpi_psd) {
 426                kfree(acpi_id_present);
 427                kfree(acpi_id_cst_present);
 428                return -ENOMEM;
 429        }
 430
 431        acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 432                            ACPI_UINT32_MAX,
 433                            read_acpi_id, NULL, NULL, NULL);
 434        acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, read_acpi_id, NULL, NULL);
 435
 436upload:
 437        if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) {
 438                unsigned int i;
 439                for_each_set_bit(i, acpi_id_present, nr_acpi_bits) {
 440                        pr_backup->acpi_id = i;
 441                        /* Mask out C-states if there are no _CST or PBLK */
 442                        pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
 443                        /* num_entries is non-zero if we evaluated _PSD */
 444                        if (acpi_psd[i].num_entries) {
 445                                memcpy(&pr_backup->performance->domain_info,
 446                                       &acpi_psd[i],
 447                                       sizeof(struct acpi_psd_package));
 448                        }
 449                        (void)upload_pm_data(pr_backup);
 450                }
 451        }
 452
 453        return 0;
 454}
 455
 456/* acpi_perf_data is a pointer to percpu data. */
 457static struct acpi_processor_performance __percpu *acpi_perf_data;
 458
 459static void free_acpi_perf_data(void)
 460{
 461        unsigned int i;
 462
 463        /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 464        for_each_possible_cpu(i)
 465                free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 466                                 ->shared_cpu_map);
 467        free_percpu(acpi_perf_data);
 468}
 469
 470static int xen_upload_processor_pm_data(void)
 471{
 472        struct acpi_processor *pr_backup = NULL;
 473        unsigned int i;
 474        int rc = 0;
 475
 476        pr_info("Uploading Xen processor PM info\n");
 477
 478        for_each_possible_cpu(i) {
 479                struct acpi_processor *_pr;
 480                _pr = per_cpu(processors, i /* APIC ID */);
 481                if (!_pr)
 482                        continue;
 483
 484                if (!pr_backup) {
 485                        pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 486                        if (pr_backup)
 487                                memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
 488                }
 489                (void)upload_pm_data(_pr);
 490        }
 491
 492        rc = check_acpi_ids(pr_backup);
 493        kfree(pr_backup);
 494
 495        return rc;
 496}
 497
 498static void xen_acpi_processor_resume_worker(struct work_struct *dummy)
 499{
 500        int rc;
 501
 502        bitmap_zero(acpi_ids_done, nr_acpi_bits);
 503
 504        rc = xen_upload_processor_pm_data();
 505        if (rc != 0)
 506                pr_info("ACPI data upload failed, error = %d\n", rc);
 507}
 508
 509static void xen_acpi_processor_resume(void)
 510{
 511        static DECLARE_WORK(wq, xen_acpi_processor_resume_worker);
 512
 513        /*
 514         * xen_upload_processor_pm_data() calls non-atomic code.
 515         * However, the context for xen_acpi_processor_resume is syscore
 516         * with only the boot CPU online and in an atomic context.
 517         *
 518         * So defer the upload for some point safer.
 519         */
 520        schedule_work(&wq);
 521}
 522
 523static struct syscore_ops xap_syscore_ops = {
 524        .resume = xen_acpi_processor_resume,
 525};
 526
 527static int __init xen_acpi_processor_init(void)
 528{
 529        unsigned int i;
 530        int rc;
 531
 532        if (!xen_initial_domain())
 533                return -ENODEV;
 534
 535        nr_acpi_bits = get_max_acpi_id() + 1;
 536        acpi_ids_done = kcalloc(BITS_TO_LONGS(nr_acpi_bits), sizeof(unsigned long), GFP_KERNEL);
 537        if (!acpi_ids_done)
 538                return -ENOMEM;
 539
 540        acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 541        if (!acpi_perf_data) {
 542                pr_debug("Memory allocation error for acpi_perf_data\n");
 543                kfree(acpi_ids_done);
 544                return -ENOMEM;
 545        }
 546        for_each_possible_cpu(i) {
 547                if (!zalloc_cpumask_var_node(
 548                        &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 549                        GFP_KERNEL, cpu_to_node(i))) {
 550                        rc = -ENOMEM;
 551                        goto err_out;
 552                }
 553        }
 554
 555        /* Do initialization in ACPI core. It is OK to fail here. */
 556        (void)acpi_processor_preregister_performance(acpi_perf_data);
 557
 558        for_each_possible_cpu(i) {
 559                struct acpi_processor *pr;
 560                struct acpi_processor_performance *perf;
 561
 562                pr = per_cpu(processors, i);
 563                perf = per_cpu_ptr(acpi_perf_data, i);
 564                if (!pr)
 565                        continue;
 566
 567                pr->performance = perf;
 568                rc = acpi_processor_get_performance_info(pr);
 569                if (rc)
 570                        goto err_out;
 571        }
 572
 573        rc = xen_upload_processor_pm_data();
 574        if (rc)
 575                goto err_unregister;
 576
 577        register_syscore_ops(&xap_syscore_ops);
 578
 579        return 0;
 580err_unregister:
 581        for_each_possible_cpu(i)
 582                acpi_processor_unregister_performance(i);
 583
 584err_out:
 585        /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 586        free_acpi_perf_data();
 587        kfree(acpi_ids_done);
 588        return rc;
 589}
 590static void __exit xen_acpi_processor_exit(void)
 591{
 592        int i;
 593
 594        unregister_syscore_ops(&xap_syscore_ops);
 595        kfree(acpi_ids_done);
 596        kfree(acpi_id_present);
 597        kfree(acpi_id_cst_present);
 598        kfree(acpi_psd);
 599        for_each_possible_cpu(i)
 600                acpi_processor_unregister_performance(i);
 601
 602        free_acpi_perf_data();
 603}
 604
 605MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
 606MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
 607MODULE_LICENSE("GPL");
 608
 609/* We want to be loaded before the CPU freq scaling drivers are loaded.
 610 * They are loaded in late_initcall. */
 611device_initcall(xen_acpi_processor_init);
 612module_exit(xen_acpi_processor_exit);
 613