drivers/xen/xen-acpi-processor.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2012 by Oracle Inc
   4  * Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
   5  *
   6  * This code borrows ideas from
   7  * https://lore.kernel.org/lkml/1322673664-14642-6-git-send-email-konrad.wilk@oracle.com
   8  * so many thanks go to Kevin Tian <kevin.tian@intel.com>
   9  * and Yu Ke <ke.yu@intel.com>.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/cpumask.h>
  15 #include <linux/cpufreq.h>
  16 #include <linux/freezer.h>
  17 #include <linux/kernel.h>
  18 #include <linux/kthread.h>
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/types.h>
  22 #include <linux/syscore_ops.h>
  23 #include <linux/acpi.h>
  24 #include <acpi/processor.h>
  25 #include <xen/xen.h>
  26 #include <xen/interface/platform.h>
  27 #include <asm/xen/hypercall.h>
  28
  29 static int no_hypercall;
  30 MODULE_PARM_DESC(off, "Inhibit the hypercall.");
  31 module_param_named(off, no_hypercall, int, 0400);
  32
  33 /*
  34  * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit
  35  * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which
  36  * can be less than what we want to put in. Instead use the 'nr_acpi_bits'
  37  * which is dynamically computed based on the MADT or x2APIC table.
  38  */
  39 static unsigned int nr_acpi_bits;
  40 /* Mutex to protect the acpi_ids_done - for CPU hotplug use. */
  41 static DEFINE_MUTEX(acpi_ids_mutex);
  42 /* Which ACPI ID we have processed from 'struct acpi_processor'. */
  43 static unsigned long *acpi_ids_done;
  44 /* Which ACPI ID exist in the SSDT/DSDT processor definitions. */
  45 static unsigned long *acpi_id_present;
  46 /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
  47 static unsigned long *acpi_id_cst_present;
  48 /* Which ACPI P-State dependencies for a enumerated processor */
  49 static struct acpi_psd_package *acpi_psd;
  50
  51 static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
  52 {
  53         struct xen_platform_op op = {
  54                 .cmd                    = XENPF_set_processor_pminfo,
  55                 .interface_version      = XENPF_INTERFACE_VERSION,
  56                 .u.set_pminfo.id        = _pr->acpi_id,
  57                 .u.set_pminfo.type      = XEN_PM_CX,
  58         };
  59         struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
  60         struct acpi_processor_cx *cx;
  61         unsigned int i, ok;
  62         int ret = 0;
  63
  64         dst_cx_states = kcalloc(_pr->power.count,
  65                                 sizeof(struct xen_processor_cx), GFP_KERNEL);
  66         if (!dst_cx_states)
  67                 return -ENOMEM;
  68
  69         for (ok = 0, i = 1; i <= _pr->power.count; i++) {
  70                 cx = &_pr->power.states[i];
  71                 if (!cx->valid)
  72                         continue;
  73
  74                 dst_cx = &(dst_cx_states[ok++]);
  75
  76                 dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
  77                 if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
  78                         dst_cx->reg.bit_width = 8;
  79                         dst_cx->reg.bit_offset = 0;
  80                         dst_cx->reg.access_size = 1;
  81                 } else {
  82                         dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
  83                         if (cx->entry_method == ACPI_CSTATE_FFH) {
  84                                 /* NATIVE_CSTATE_BEYOND_HALT */
  85                                 dst_cx->reg.bit_offset = 2;
  86                                 dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
  87                         }
  88                         dst_cx->reg.access_size = 0;
  89                 }
  90                 dst_cx->reg.address = cx->address;
  91
  92                 dst_cx->type = cx->type;
  93                 dst_cx->latency = cx->latency;
  94
  95                 dst_cx->dpcnt = 0;
  96                 set_xen_guest_handle(dst_cx->dp, NULL);
  97         }
  98         if (!ok) {
  99                 pr_debug("No _Cx for ACPI CPU %u\n", _pr->acpi_id);
 100                 kfree(dst_cx_states);
 101                 return -EINVAL;
 102         }
 103         op.u.set_pminfo.power.count = ok;
 104         op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
 105         op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
 106         op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
 107         op.u.set_pminfo.power.flags.power_setup_done =
 108                 _pr->flags.power_setup_done;
 109
 110         set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);
 111
 112         if (!no_hypercall)
 113                 ret = HYPERVISOR_platform_op(&op);
 114
 115         if (!ret) {
 116                 pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id);
 117                 for (i = 1; i <= _pr->power.count; i++) {
 118                         cx = &_pr->power.states[i];
 119                         if (!cx->valid)
 120                                 continue;
 121                         pr_debug("     C%d: %s %d uS\n",
 122                                  cx->type, cx->desc, (u32)cx->latency);
 123                 }
 124         } else if ((ret != -EINVAL) && (ret != -ENOSYS))
 125                 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
 126                  * table is referencing a non-existing CPU - which can happen
 127                  * with broken ACPI tables. */
 128                 pr_err("(CX): Hypervisor error (%d) for ACPI CPU%u\n",
 129                        ret, _pr->acpi_id);
 130
 131         kfree(dst_cx_states);
 132
 133         return ret;
 134 }
 135 static struct xen_processor_px *
 136 xen_copy_pss_data(struct acpi_processor *_pr,
 137                   struct xen_processor_performance *dst_perf)
 138 {
 139         struct xen_processor_px *dst_states = NULL;
 140         unsigned int i;
 141
 142         BUILD_BUG_ON(sizeof(struct xen_processor_px) !=
 143                      sizeof(struct acpi_processor_px));
 144
 145         dst_states = kcalloc(_pr->performance->state_count,
 146                              sizeof(struct xen_processor_px), GFP_KERNEL);
 147         if (!dst_states)
 148                 return ERR_PTR(-ENOMEM);
 149
 150         dst_perf->state_count = _pr->performance->state_count;
 151         for (i = 0; i < _pr->performance->state_count; i++) {
 152                 /* Fortunatly for us, they are both the same size */
 153                 memcpy(&(dst_states[i]), &(_pr->performance->states[i]),
 154                        sizeof(struct acpi_processor_px));
 155         }
 156         return dst_states;
 157 }
 158 static int xen_copy_psd_data(struct acpi_processor *_pr,
 159                              struct xen_processor_performance *dst)
 160 {
 161         struct acpi_psd_package *pdomain;
 162
 163         BUILD_BUG_ON(sizeof(struct xen_psd_package) !=
 164                      sizeof(struct acpi_psd_package));
 165
 166         /* This information is enumerated only if acpi_processor_preregister_performance
 167          * has been called.
 168          */
 169         dst->shared_type = _pr->performance->shared_type;
 170
 171         pdomain = &(_pr->performance->domain_info);
 172
 173         /* 'acpi_processor_preregister_performance' does not parse if the
 174          * num_processors <= 1, but Xen still requires it. Do it manually here.
 175          */
 176         if (pdomain->num_processors <= 1) {
 177                 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
 178                         dst->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 179                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
 180                         dst->shared_type = CPUFREQ_SHARED_TYPE_HW;
 181                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
 182                         dst->shared_type = CPUFREQ_SHARED_TYPE_ANY;
 183
 184         }
 185         memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package));
 186         return 0;
 187 }
 188 static int xen_copy_pct_data(struct acpi_pct_register *pct,
 189                              struct xen_pct_register *dst_pct)
 190 {
 191         /* It would be nice if you could just do 'memcpy(pct, dst_pct') but
 192          * sadly the Xen structure did not have the proper padding so the
 193          * descriptor field takes two (dst_pct) bytes instead of one (pct).
 194          */
 195         dst_pct->descriptor = pct->descriptor;
 196         dst_pct->length = pct->length;
 197         dst_pct->space_id = pct->space_id;
 198         dst_pct->bit_width = pct->bit_width;
 199         dst_pct->bit_offset = pct->bit_offset;
 200         dst_pct->reserved = pct->reserved;
 201         dst_pct->address = pct->address;
 202         return 0;
 203 }
 204 static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
 205 {
 206         int ret = 0;
 207         struct xen_platform_op op = {
 208                 .cmd                    = XENPF_set_processor_pminfo,
 209                 .interface_version      = XENPF_INTERFACE_VERSION,
 210                 .u.set_pminfo.id        = _pr->acpi_id,
 211                 .u.set_pminfo.type      = XEN_PM_PX,
 212         };
 213         struct xen_processor_performance *dst_perf;
 214         struct xen_processor_px *dst_states = NULL;
 215
 216         dst_perf = &op.u.set_pminfo.perf;
 217
 218         dst_perf->platform_limit = _pr->performance_platform_limit;
 219         dst_perf->flags |= XEN_PX_PPC;
 220         xen_copy_pct_data(&(_pr->performance->control_register),
 221                           &dst_perf->control_register);
 222         xen_copy_pct_data(&(_pr->performance->status_register),
 223                           &dst_perf->status_register);
 224         dst_perf->flags |= XEN_PX_PCT;
 225         dst_states = xen_copy_pss_data(_pr, dst_perf);
 226         if (!IS_ERR_OR_NULL(dst_states)) {
 227                 set_xen_guest_handle(dst_perf->states, dst_states);
 228                 dst_perf->flags |= XEN_PX_PSS;
 229         }
 230         if (!xen_copy_psd_data(_pr, dst_perf))
 231                 dst_perf->flags |= XEN_PX_PSD;
 232
 233         if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) {
 234                 pr_warn("ACPI CPU%u missing some P-state data (%x), skipping\n",
 235                         _pr->acpi_id, dst_perf->flags);
 236                 ret = -ENODEV;
 237                 goto err_free;
 238         }
 239
 240         if (!no_hypercall)
 241                 ret = HYPERVISOR_platform_op(&op);
 242
 243         if (!ret) {
 244                 struct acpi_processor_performance *perf;
 245                 unsigned int i;
 246
 247                 perf = _pr->performance;
 248                 pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id);
 249                 for (i = 0; i < perf->state_count; i++) {
 250                         pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
 251                         (i == perf->state ? '*' : ' '), i,
 252                         (u32) perf->states[i].core_frequency,
 253                         (u32) perf->states[i].power,
 254                         (u32) perf->states[i].transition_latency);
 255                 }
 256         } else if ((ret != -EINVAL) && (ret != -ENOSYS))
 257                 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
 258                  * table is referencing a non-existing CPU - which can happen
 259                  * with broken ACPI tables. */
 260                 pr_warn("(_PXX): Hypervisor error (%d) for ACPI CPU%u\n",
 261                         ret, _pr->acpi_id);
 262 err_free:
 263         if (!IS_ERR_OR_NULL(dst_states))
 264                 kfree(dst_states);
 265
 266         return ret;
 267 }
 268 static int upload_pm_data(struct acpi_processor *_pr)
 269 {
 270         int err = 0;
 271
 272         mutex_lock(&acpi_ids_mutex);
 273         if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) {
 274                 mutex_unlock(&acpi_ids_mutex);
 275                 return -EBUSY;
 276         }
 277         if (_pr->flags.power)
 278                 err = push_cxx_to_hypervisor(_pr);
 279
 280         if (_pr->performance && _pr->performance->states)
 281                 err |= push_pxx_to_hypervisor(_pr);
 282
 283         mutex_unlock(&acpi_ids_mutex);
 284         return err;
 285 }
 286 static unsigned int __init get_max_acpi_id(void)
 287 {
 288         struct xenpf_pcpuinfo *info;
 289         struct xen_platform_op op = {
 290                 .cmd = XENPF_get_cpuinfo,
 291                 .interface_version = XENPF_INTERFACE_VERSION,
 292         };
 293         int ret = 0;
 294         unsigned int i, last_cpu, max_acpi_id = 0;
 295
 296         info = &op.u.pcpu_info;
 297         info->xen_cpuid = 0;
 298
 299         ret = HYPERVISOR_platform_op(&op);
 300         if (ret)
 301                 return NR_CPUS;
 302
 303         /* The max_present is the same irregardless of the xen_cpuid */
 304         last_cpu = op.u.pcpu_info.max_present;
 305         for (i = 0; i <= last_cpu; i++) {
 306                 info->xen_cpuid = i;
 307                 ret = HYPERVISOR_platform_op(&op);
 308                 if (ret)
 309                         continue;
 310                 max_acpi_id = max(info->acpi_id, max_acpi_id);
 311         }
 312         max_acpi_id *= 2; /* Slack for CPU hotplug support. */
 313         pr_debug("Max ACPI ID: %u\n", max_acpi_id);
 314         return max_acpi_id;
 315 }
 316 /*
 317  * The read_acpi_id and check_acpi_ids are there to support the Xen
 318  * oddity of virtual CPUs != physical CPUs in the initial domain.
 319  * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line
 320  * which will band the amount of CPUs the initial domain can see.
 321  * In general that is OK, except it plays havoc with any of the
 322  * for_each_[present|online]_cpu macros which are banded to the virtual
 323  * CPU amount.
 324  */
 325 static acpi_status
 326 read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
 327 {
 328         u32 acpi_id;
 329         acpi_status status;
 330         acpi_object_type acpi_type;
 331         unsigned long long tmp;
 332         union acpi_object object = { 0 };
 333         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 334         acpi_io_address pblk = 0;
 335
 336         status = acpi_get_type(handle, &acpi_type);
 337         if (ACPI_FAILURE(status))
 338                 return AE_OK;
 339
 340         switch (acpi_type) {
 341         case ACPI_TYPE_PROCESSOR:
 342                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 343                 if (ACPI_FAILURE(status))
 344                         return AE_OK;
 345                 acpi_id = object.processor.proc_id;
 346                 pblk = object.processor.pblk_address;
 347                 break;
 348         case ACPI_TYPE_DEVICE:
 349                 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
 350                 if (ACPI_FAILURE(status))
 351                         return AE_OK;
 352                 acpi_id = tmp;
 353                 break;
 354         default:
 355                 return AE_OK;
 356         }
 357         if (invalid_phys_cpuid(acpi_get_phys_id(handle,
 358                                                 acpi_type == ACPI_TYPE_DEVICE,
 359                                                 acpi_id))) {
 360                 pr_debug("CPU with ACPI ID %u is unavailable\n", acpi_id);
 361                 return AE_OK;
 362         }
 363         /* There are more ACPI Processor objects than in x2APIC or MADT.
 364          * This can happen with incorrect ACPI SSDT declerations. */
 365         if (acpi_id >= nr_acpi_bits) {
 366                 pr_debug("max acpi id %u, trying to set %u\n",
 367                          nr_acpi_bits - 1, acpi_id);
 368                 return AE_OK;
 369         }
 370         /* OK, There is a ACPI Processor object */
 371         __set_bit(acpi_id, acpi_id_present);
 372
 373         pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
 374
 375         /* It has P-state dependencies */
 376         if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) {
 377                 pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n",
 378                          acpi_id, acpi_psd[acpi_id].coord_type,
 379                          acpi_psd[acpi_id].domain);
 380         }
 381
 382         status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 383         if (ACPI_FAILURE(status)) {
 384                 if (!pblk)
 385                         return AE_OK;
 386         }
 387         /* .. and it has a C-state */
 388         __set_bit(acpi_id, acpi_id_cst_present);
 389
 390         return AE_OK;
 391 }
 392 static int check_acpi_ids(struct acpi_processor *pr_backup)
 393 {
 394
 395         if (!pr_backup)
 396                 return -ENODEV;
 397
 398         if (acpi_id_present && acpi_id_cst_present)
 399                 /* OK, done this once .. skip to uploading */
 400                 goto upload;
 401
 402         /* All online CPUs have been processed at this stage. Now verify
 403          * whether in fact "online CPUs" == physical CPUs.
 404          */
 405         acpi_id_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 406         if (!acpi_id_present)
 407                 return -ENOMEM;
 408
 409         acpi_id_cst_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 410         if (!acpi_id_cst_present) {
 411                 bitmap_free(acpi_id_present);
 412                 return -ENOMEM;
 413         }
 414
 415         acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package),
 416                            GFP_KERNEL);
 417         if (!acpi_psd) {
 418                 bitmap_free(acpi_id_present);
 419                 bitmap_free(acpi_id_cst_present);
 420                 return -ENOMEM;
 421         }
 422
 423         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 424                             ACPI_UINT32_MAX,
 425                             read_acpi_id, NULL, NULL, NULL);
 426         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, read_acpi_id, NULL, NULL);
 427
 428 upload:
 429         if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) {
 430                 unsigned int i;
 431                 for_each_set_bit(i, acpi_id_present, nr_acpi_bits) {
 432                         pr_backup->acpi_id = i;
 433                         /* Mask out C-states if there are no _CST or PBLK */
 434                         pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
 435                         /* num_entries is non-zero if we evaluated _PSD */
 436                         if (acpi_psd[i].num_entries) {
 437                                 memcpy(&pr_backup->performance->domain_info,
 438                                        &acpi_psd[i],
 439                                        sizeof(struct acpi_psd_package));
 440                         }
 441                         (void)upload_pm_data(pr_backup);
 442                 }
 443         }
 444
 445         return 0;
 446 }
 447
 448 /* acpi_perf_data is a pointer to percpu data. */
 449 static struct acpi_processor_performance __percpu *acpi_perf_data;
 450
 451 static void free_acpi_perf_data(void)
 452 {
 453         int i;
 454
 455         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 456         for_each_possible_cpu(i)
 457                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 458                                  ->shared_cpu_map);
 459         free_percpu(acpi_perf_data);
 460 }
 461
 462 static int xen_upload_processor_pm_data(void)
 463 {
 464         struct acpi_processor *pr_backup = NULL;
 465         int i;
 466         int rc = 0;
 467
 468         pr_info("Uploading Xen processor PM info\n");
 469
 470         for_each_possible_cpu(i) {
 471                 struct acpi_processor *_pr;
 472                 _pr = per_cpu(processors, i /* APIC ID */);
 473                 if (!_pr)
 474                         continue;
 475
 476                 if (!pr_backup)
 477                         pr_backup = kmemdup(_pr, sizeof(*_pr), GFP_KERNEL);
 478                 (void)upload_pm_data(_pr);
 479         }
 480
 481         rc = check_acpi_ids(pr_backup);
 482         kfree(pr_backup);
 483
 484         return rc;
 485 }
 486
 487 static void xen_acpi_processor_resume_worker(struct work_struct *dummy)
 488 {
 489         int rc;
 490
 491         bitmap_zero(acpi_ids_done, nr_acpi_bits);
 492
 493         rc = xen_upload_processor_pm_data();
 494         if (rc != 0)
 495                 pr_info("ACPI data upload failed, error = %d\n", rc);
 496 }
 497
 498 static void xen_acpi_processor_resume(void)
 499 {
 500         static DECLARE_WORK(wq, xen_acpi_processor_resume_worker);
 501
 502         /*
 503          * xen_upload_processor_pm_data() calls non-atomic code.
 504          * However, the context for xen_acpi_processor_resume is syscore
 505          * with only the boot CPU online and in an atomic context.
 506          *
 507          * So defer the upload for some point safer.
 508          */
 509         schedule_work(&wq);
 510 }
 511
 512 static struct syscore_ops xap_syscore_ops = {
 513         .resume = xen_acpi_processor_resume,
 514 };
 515
 516 static int __init xen_acpi_processor_init(void)
 517 {
 518         int i;
 519         int rc;
 520
 521         if (!xen_initial_domain())
 522                 return -ENODEV;
 523
 524         nr_acpi_bits = get_max_acpi_id() + 1;
 525         acpi_ids_done = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 526         if (!acpi_ids_done)
 527                 return -ENOMEM;
 528
 529         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 530         if (!acpi_perf_data) {
 531                 pr_debug("Memory allocation error for acpi_perf_data\n");
 532                 bitmap_free(acpi_ids_done);
 533                 return -ENOMEM;
 534         }
 535         for_each_possible_cpu(i) {
 536                 if (!zalloc_cpumask_var_node(
 537                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 538                         GFP_KERNEL, cpu_to_node(i))) {
 539                         rc = -ENOMEM;
 540                         goto err_out;
 541                 }
 542         }
 543
 544         /* Do initialization in ACPI core. It is OK to fail here. */
 545         (void)acpi_processor_preregister_performance(acpi_perf_data);
 546
 547         for_each_possible_cpu(i) {
 548                 struct acpi_processor *pr;
 549                 struct acpi_processor_performance *perf;
 550
 551                 pr = per_cpu(processors, i);
 552                 perf = per_cpu_ptr(acpi_perf_data, i);
 553                 if (!pr)
 554                         continue;
 555
 556                 pr->performance = perf;
 557                 rc = acpi_processor_get_performance_info(pr);
 558                 if (rc)
 559                         goto err_out;
 560         }
 561
 562         rc = xen_upload_processor_pm_data();
 563         if (rc)
 564                 goto err_unregister;
 565
 566         register_syscore_ops(&xap_syscore_ops);
 567
 568         return 0;
 569 err_unregister:
 570         for_each_possible_cpu(i)
 571                 acpi_processor_unregister_performance(i);
 572
 573 err_out:
 574         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 575         free_acpi_perf_data();
 576         bitmap_free(acpi_ids_done);
 577         return rc;
 578 }
 579 static void __exit xen_acpi_processor_exit(void)
 580 {
 581         int i;
 582
 583         unregister_syscore_ops(&xap_syscore_ops);
 584         bitmap_free(acpi_ids_done);
 585         bitmap_free(acpi_id_present);
 586         bitmap_free(acpi_id_cst_present);
 587         kfree(acpi_psd);
 588         for_each_possible_cpu(i)
 589                 acpi_processor_unregister_performance(i);
 590
 591         free_acpi_perf_data();
 592 }
 593
 594 MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
 595 MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
 596 MODULE_LICENSE("GPL");
 597
 598 /* We want to be loaded before the CPU freq scaling drivers are loaded.
 599  * They are loaded in late_initcall. */
 600 device_initcall(xen_acpi_processor_init);
 601 module_exit(xen_acpi_processor_exit);