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 https://lkml.org/lkml/2011/11/30/249
   7  * so many thanks go to Kevin Tian <kevin.tian@intel.com>
   8  * and Yu Ke <ke.yu@intel.com>.
   9  */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/cpumask.h>
  14 #include <linux/cpufreq.h>
  15 #include <linux/freezer.h>
  16 #include <linux/kernel.h>
  17 #include <linux/kthread.h>
  18 #include <linux/init.h>
  19 #include <linux/module.h>
  20 #include <linux/types.h>
  21 #include <linux/syscore_ops.h>
  22 #include <linux/acpi.h>
  23 #include <acpi/processor.h>
  24 #include <xen/xen.h>
  25 #include <xen/interface/platform.h>
  26 #include <asm/xen/hypercall.h>
  27
  28 static int no_hypercall;
  29 MODULE_PARM_DESC(off, "Inhibit the hypercall.");
  30 module_param_named(off, no_hypercall, int, 0400);
  31
  32 /*
  33  * Note: Do not convert the acpi_id* below to cpumask_var_t or use cpumask_bit
  34  * - as those shrink to nr_cpu_bits (which is dependent on possible_cpu), which
  35  * can be less than what we want to put in. Instead use the 'nr_acpi_bits'
  36  * which is dynamically computed based on the MADT or x2APIC table.
  37  */
  38 static unsigned int nr_acpi_bits;
  39 /* Mutex to protect the acpi_ids_done - for CPU hotplug use. */
  40 static DEFINE_MUTEX(acpi_ids_mutex);
  41 /* Which ACPI ID we have processed from 'struct acpi_processor'. */
  42 static unsigned long *acpi_ids_done;
  43 /* Which ACPI ID exist in the SSDT/DSDT processor definitions. */
  44 static unsigned long *acpi_id_present;
  45 /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
  46 static unsigned long *acpi_id_cst_present;
  47 /* Which ACPI P-State dependencies for a enumerated processor */
  48 static struct acpi_psd_package *acpi_psd;
  49
  50 static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
  51 {
  52         struct xen_platform_op op = {
  53                 .cmd                    = XENPF_set_processor_pminfo,
  54                 .interface_version      = XENPF_INTERFACE_VERSION,
  55                 .u.set_pminfo.id        = _pr->acpi_id,
  56                 .u.set_pminfo.type      = XEN_PM_CX,
  57         };
  58         struct xen_processor_cx *dst_cx, *dst_cx_states = NULL;
  59         struct acpi_processor_cx *cx;
  60         unsigned int i, ok;
  61         int ret = 0;
  62
  63         dst_cx_states = kcalloc(_pr->power.count,
  64                                 sizeof(struct xen_processor_cx), GFP_KERNEL);
  65         if (!dst_cx_states)
  66                 return -ENOMEM;
  67
  68         for (ok = 0, i = 1; i <= _pr->power.count; i++) {
  69                 cx = &_pr->power.states[i];
  70                 if (!cx->valid)
  71                         continue;
  72
  73                 dst_cx = &(dst_cx_states[ok++]);
  74
  75                 dst_cx->reg.space_id = ACPI_ADR_SPACE_SYSTEM_IO;
  76                 if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
  77                         dst_cx->reg.bit_width = 8;
  78                         dst_cx->reg.bit_offset = 0;
  79                         dst_cx->reg.access_size = 1;
  80                 } else {
  81                         dst_cx->reg.space_id = ACPI_ADR_SPACE_FIXED_HARDWARE;
  82                         if (cx->entry_method == ACPI_CSTATE_FFH) {
  83                                 /* NATIVE_CSTATE_BEYOND_HALT */
  84                                 dst_cx->reg.bit_offset = 2;
  85                                 dst_cx->reg.bit_width = 1; /* VENDOR_INTEL */
  86                         }
  87                         dst_cx->reg.access_size = 0;
  88                 }
  89                 dst_cx->reg.address = cx->address;
  90
  91                 dst_cx->type = cx->type;
  92                 dst_cx->latency = cx->latency;
  93
  94                 dst_cx->dpcnt = 0;
  95                 set_xen_guest_handle(dst_cx->dp, NULL);
  96         }
  97         if (!ok) {
  98                 pr_debug("No _Cx for ACPI CPU %u\n", _pr->acpi_id);
  99                 kfree(dst_cx_states);
 100                 return -EINVAL;
 101         }
 102         op.u.set_pminfo.power.count = ok;
 103         op.u.set_pminfo.power.flags.bm_control = _pr->flags.bm_control;
 104         op.u.set_pminfo.power.flags.bm_check = _pr->flags.bm_check;
 105         op.u.set_pminfo.power.flags.has_cst = _pr->flags.has_cst;
 106         op.u.set_pminfo.power.flags.power_setup_done =
 107                 _pr->flags.power_setup_done;
 108
 109         set_xen_guest_handle(op.u.set_pminfo.power.states, dst_cx_states);
 110
 111         if (!no_hypercall)
 112                 ret = HYPERVISOR_platform_op(&op);
 113
 114         if (!ret) {
 115                 pr_debug("ACPI CPU%u - C-states uploaded.\n", _pr->acpi_id);
 116                 for (i = 1; i <= _pr->power.count; i++) {
 117                         cx = &_pr->power.states[i];
 118                         if (!cx->valid)
 119                                 continue;
 120                         pr_debug("     C%d: %s %d uS\n",
 121                                  cx->type, cx->desc, (u32)cx->latency);
 122                 }
 123         } else if ((ret != -EINVAL) && (ret != -ENOSYS))
 124                 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
 125                  * table is referencing a non-existing CPU - which can happen
 126                  * with broken ACPI tables. */
 127                 pr_err("(CX): Hypervisor error (%d) for ACPI CPU%u\n",
 128                        ret, _pr->acpi_id);
 129
 130         kfree(dst_cx_states);
 131
 132         return ret;
 133 }
 134 static struct xen_processor_px *
 135 xen_copy_pss_data(struct acpi_processor *_pr,
 136                   struct xen_processor_performance *dst_perf)
 137 {
 138         struct xen_processor_px *dst_states = NULL;
 139         unsigned int i;
 140
 141         BUILD_BUG_ON(sizeof(struct xen_processor_px) !=
 142                      sizeof(struct acpi_processor_px));
 143
 144         dst_states = kcalloc(_pr->performance->state_count,
 145                              sizeof(struct xen_processor_px), GFP_KERNEL);
 146         if (!dst_states)
 147                 return ERR_PTR(-ENOMEM);
 148
 149         dst_perf->state_count = _pr->performance->state_count;
 150         for (i = 0; i < _pr->performance->state_count; i++) {
 151                 /* Fortunatly for us, they are both the same size */
 152                 memcpy(&(dst_states[i]), &(_pr->performance->states[i]),
 153                        sizeof(struct acpi_processor_px));
 154         }
 155         return dst_states;
 156 }
 157 static int xen_copy_psd_data(struct acpi_processor *_pr,
 158                              struct xen_processor_performance *dst)
 159 {
 160         struct acpi_psd_package *pdomain;
 161
 162         BUILD_BUG_ON(sizeof(struct xen_psd_package) !=
 163                      sizeof(struct acpi_psd_package));
 164
 165         /* This information is enumerated only if acpi_processor_preregister_performance
 166          * has been called.
 167          */
 168         dst->shared_type = _pr->performance->shared_type;
 169
 170         pdomain = &(_pr->performance->domain_info);
 171
 172         /* 'acpi_processor_preregister_performance' does not parse if the
 173          * num_processors <= 1, but Xen still requires it. Do it manually here.
 174          */
 175         if (pdomain->num_processors <= 1) {
 176                 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
 177                         dst->shared_type = CPUFREQ_SHARED_TYPE_ALL;
 178                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
 179                         dst->shared_type = CPUFREQ_SHARED_TYPE_HW;
 180                 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
 181                         dst->shared_type = CPUFREQ_SHARED_TYPE_ANY;
 182
 183         }
 184         memcpy(&(dst->domain_info), pdomain, sizeof(struct acpi_psd_package));
 185         return 0;
 186 }
 187 static int xen_copy_pct_data(struct acpi_pct_register *pct,
 188                              struct xen_pct_register *dst_pct)
 189 {
 190         /* It would be nice if you could just do 'memcpy(pct, dst_pct') but
 191          * sadly the Xen structure did not have the proper padding so the
 192          * descriptor field takes two (dst_pct) bytes instead of one (pct).
 193          */
 194         dst_pct->descriptor = pct->descriptor;
 195         dst_pct->length = pct->length;
 196         dst_pct->space_id = pct->space_id;
 197         dst_pct->bit_width = pct->bit_width;
 198         dst_pct->bit_offset = pct->bit_offset;
 199         dst_pct->reserved = pct->reserved;
 200         dst_pct->address = pct->address;
 201         return 0;
 202 }
 203 static int push_pxx_to_hypervisor(struct acpi_processor *_pr)
 204 {
 205         int ret = 0;
 206         struct xen_platform_op op = {
 207                 .cmd                    = XENPF_set_processor_pminfo,
 208                 .interface_version      = XENPF_INTERFACE_VERSION,
 209                 .u.set_pminfo.id        = _pr->acpi_id,
 210                 .u.set_pminfo.type      = XEN_PM_PX,
 211         };
 212         struct xen_processor_performance *dst_perf;
 213         struct xen_processor_px *dst_states = NULL;
 214
 215         dst_perf = &op.u.set_pminfo.perf;
 216
 217         dst_perf->platform_limit = _pr->performance_platform_limit;
 218         dst_perf->flags |= XEN_PX_PPC;
 219         xen_copy_pct_data(&(_pr->performance->control_register),
 220                           &dst_perf->control_register);
 221         xen_copy_pct_data(&(_pr->performance->status_register),
 222                           &dst_perf->status_register);
 223         dst_perf->flags |= XEN_PX_PCT;
 224         dst_states = xen_copy_pss_data(_pr, dst_perf);
 225         if (!IS_ERR_OR_NULL(dst_states)) {
 226                 set_xen_guest_handle(dst_perf->states, dst_states);
 227                 dst_perf->flags |= XEN_PX_PSS;
 228         }
 229         if (!xen_copy_psd_data(_pr, dst_perf))
 230                 dst_perf->flags |= XEN_PX_PSD;
 231
 232         if (dst_perf->flags != (XEN_PX_PSD | XEN_PX_PSS | XEN_PX_PCT | XEN_PX_PPC)) {
 233                 pr_warn("ACPI CPU%u missing some P-state data (%x), skipping\n",
 234                         _pr->acpi_id, dst_perf->flags);
 235                 ret = -ENODEV;
 236                 goto err_free;
 237         }
 238
 239         if (!no_hypercall)
 240                 ret = HYPERVISOR_platform_op(&op);
 241
 242         if (!ret) {
 243                 struct acpi_processor_performance *perf;
 244                 unsigned int i;
 245
 246                 perf = _pr->performance;
 247                 pr_debug("ACPI CPU%u - P-states uploaded.\n", _pr->acpi_id);
 248                 for (i = 0; i < perf->state_count; i++) {
 249                         pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
 250                         (i == perf->state ? '*' : ' '), i,
 251                         (u32) perf->states[i].core_frequency,
 252                         (u32) perf->states[i].power,
 253                         (u32) perf->states[i].transition_latency);
 254                 }
 255         } else if ((ret != -EINVAL) && (ret != -ENOSYS))
 256                 /* EINVAL means the ACPI ID is incorrect - meaning the ACPI
 257                  * table is referencing a non-existing CPU - which can happen
 258                  * with broken ACPI tables. */
 259                 pr_warn("(_PXX): Hypervisor error (%d) for ACPI CPU%u\n",
 260                         ret, _pr->acpi_id);
 261 err_free:
 262         if (!IS_ERR_OR_NULL(dst_states))
 263                 kfree(dst_states);
 264
 265         return ret;
 266 }
 267 static int upload_pm_data(struct acpi_processor *_pr)
 268 {
 269         int err = 0;
 270
 271         mutex_lock(&acpi_ids_mutex);
 272         if (__test_and_set_bit(_pr->acpi_id, acpi_ids_done)) {
 273                 mutex_unlock(&acpi_ids_mutex);
 274                 return -EBUSY;
 275         }
 276         if (_pr->flags.power)
 277                 err = push_cxx_to_hypervisor(_pr);
 278
 279         if (_pr->performance && _pr->performance->states)
 280                 err |= push_pxx_to_hypervisor(_pr);
 281
 282         mutex_unlock(&acpi_ids_mutex);
 283         return err;
 284 }
 285 static unsigned int __init get_max_acpi_id(void)
 286 {
 287         struct xenpf_pcpuinfo *info;
 288         struct xen_platform_op op = {
 289                 .cmd = XENPF_get_cpuinfo,
 290                 .interface_version = XENPF_INTERFACE_VERSION,
 291         };
 292         int ret = 0;
 293         unsigned int i, last_cpu, max_acpi_id = 0;
 294
 295         info = &op.u.pcpu_info;
 296         info->xen_cpuid = 0;
 297
 298         ret = HYPERVISOR_platform_op(&op);
 299         if (ret)
 300                 return NR_CPUS;
 301
 302         /* The max_present is the same irregardless of the xen_cpuid */
 303         last_cpu = op.u.pcpu_info.max_present;
 304         for (i = 0; i <= last_cpu; i++) {
 305                 info->xen_cpuid = i;
 306                 ret = HYPERVISOR_platform_op(&op);
 307                 if (ret)
 308                         continue;
 309                 max_acpi_id = max(info->acpi_id, max_acpi_id);
 310         }
 311         max_acpi_id *= 2; /* Slack for CPU hotplug support. */
 312         pr_debug("Max ACPI ID: %u\n", max_acpi_id);
 313         return max_acpi_id;
 314 }
 315 /*
 316  * The read_acpi_id and check_acpi_ids are there to support the Xen
 317  * oddity of virtual CPUs != physical CPUs in the initial domain.
 318  * The user can supply 'xen_max_vcpus=X' on the Xen hypervisor line
 319  * which will band the amount of CPUs the initial domain can see.
 320  * In general that is OK, except it plays havoc with any of the
 321  * for_each_[present|online]_cpu macros which are banded to the virtual
 322  * CPU amount.
 323  */
 324 static acpi_status
 325 read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
 326 {
 327         u32 acpi_id;
 328         acpi_status status;
 329         acpi_object_type acpi_type;
 330         unsigned long long tmp;
 331         union acpi_object object = { 0 };
 332         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 333         acpi_io_address pblk = 0;
 334
 335         status = acpi_get_type(handle, &acpi_type);
 336         if (ACPI_FAILURE(status))
 337                 return AE_OK;
 338
 339         switch (acpi_type) {
 340         case ACPI_TYPE_PROCESSOR:
 341                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 342                 if (ACPI_FAILURE(status))
 343                         return AE_OK;
 344                 acpi_id = object.processor.proc_id;
 345                 pblk = object.processor.pblk_address;
 346                 break;
 347         case ACPI_TYPE_DEVICE:
 348                 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
 349                 if (ACPI_FAILURE(status))
 350                         return AE_OK;
 351                 acpi_id = tmp;
 352                 break;
 353         default:
 354                 return AE_OK;
 355         }
 356         if (invalid_phys_cpuid(acpi_get_phys_id(handle,
 357                                                 acpi_type == ACPI_TYPE_DEVICE,
 358                                                 acpi_id))) {
 359                 pr_debug("CPU with ACPI ID %u is unavailable\n", acpi_id);
 360                 return AE_OK;
 361         }
 362         /* There are more ACPI Processor objects than in x2APIC or MADT.
 363          * This can happen with incorrect ACPI SSDT declerations. */
 364         if (acpi_id >= nr_acpi_bits) {
 365                 pr_debug("max acpi id %u, trying to set %u\n",
 366                          nr_acpi_bits - 1, acpi_id);
 367                 return AE_OK;
 368         }
 369         /* OK, There is a ACPI Processor object */
 370         __set_bit(acpi_id, acpi_id_present);
 371
 372         pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
 373
 374         /* It has P-state dependencies */
 375         if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) {
 376                 pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n",
 377                          acpi_id, acpi_psd[acpi_id].coord_type,
 378                          acpi_psd[acpi_id].domain);
 379         }
 380
 381         status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 382         if (ACPI_FAILURE(status)) {
 383                 if (!pblk)
 384                         return AE_OK;
 385         }
 386         /* .. and it has a C-state */
 387         __set_bit(acpi_id, acpi_id_cst_present);
 388
 389         return AE_OK;
 390 }
 391 static int check_acpi_ids(struct acpi_processor *pr_backup)
 392 {
 393
 394         if (!pr_backup)
 395                 return -ENODEV;
 396
 397         if (acpi_id_present && acpi_id_cst_present)
 398                 /* OK, done this once .. skip to uploading */
 399                 goto upload;
 400
 401         /* All online CPUs have been processed at this stage. Now verify
 402          * whether in fact "online CPUs" == physical CPUs.
 403          */
 404         acpi_id_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 405         if (!acpi_id_present)
 406                 return -ENOMEM;
 407
 408         acpi_id_cst_present = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 409         if (!acpi_id_cst_present) {
 410                 bitmap_free(acpi_id_present);
 411                 return -ENOMEM;
 412         }
 413
 414         acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package),
 415                            GFP_KERNEL);
 416         if (!acpi_psd) {
 417                 bitmap_free(acpi_id_present);
 418                 bitmap_free(acpi_id_cst_present);
 419                 return -ENOMEM;
 420         }
 421
 422         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 423                             ACPI_UINT32_MAX,
 424                             read_acpi_id, NULL, NULL, NULL);
 425         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, read_acpi_id, NULL, NULL);
 426
 427 upload:
 428         if (!bitmap_equal(acpi_id_present, acpi_ids_done, nr_acpi_bits)) {
 429                 unsigned int i;
 430                 for_each_set_bit(i, acpi_id_present, nr_acpi_bits) {
 431                         pr_backup->acpi_id = i;
 432                         /* Mask out C-states if there are no _CST or PBLK */
 433                         pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
 434                         /* num_entries is non-zero if we evaluated _PSD */
 435                         if (acpi_psd[i].num_entries) {
 436                                 memcpy(&pr_backup->performance->domain_info,
 437                                        &acpi_psd[i],
 438                                        sizeof(struct acpi_psd_package));
 439                         }
 440                         (void)upload_pm_data(pr_backup);
 441                 }
 442         }
 443
 444         return 0;
 445 }
 446
 447 /* acpi_perf_data is a pointer to percpu data. */
 448 static struct acpi_processor_performance __percpu *acpi_perf_data;
 449
 450 static void free_acpi_perf_data(void)
 451 {
 452         unsigned int i;
 453
 454         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
 455         for_each_possible_cpu(i)
 456                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
 457                                  ->shared_cpu_map);
 458         free_percpu(acpi_perf_data);
 459 }
 460
 461 static int xen_upload_processor_pm_data(void)
 462 {
 463         struct acpi_processor *pr_backup = NULL;
 464         unsigned int i;
 465         int rc = 0;
 466
 467         pr_info("Uploading Xen processor PM info\n");
 468
 469         for_each_possible_cpu(i) {
 470                 struct acpi_processor *_pr;
 471                 _pr = per_cpu(processors, i /* APIC ID */);
 472                 if (!_pr)
 473                         continue;
 474
 475                 if (!pr_backup) {
 476                         pr_backup = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 477                         if (pr_backup)
 478                                 memcpy(pr_backup, _pr, sizeof(struct acpi_processor));
 479                 }
 480                 (void)upload_pm_data(_pr);
 481         }
 482
 483         rc = check_acpi_ids(pr_backup);
 484         kfree(pr_backup);
 485
 486         return rc;
 487 }
 488
 489 static void xen_acpi_processor_resume_worker(struct work_struct *dummy)
 490 {
 491         int rc;
 492
 493         bitmap_zero(acpi_ids_done, nr_acpi_bits);
 494
 495         rc = xen_upload_processor_pm_data();
 496         if (rc != 0)
 497                 pr_info("ACPI data upload failed, error = %d\n", rc);
 498 }
 499
 500 static void xen_acpi_processor_resume(void)
 501 {
 502         static DECLARE_WORK(wq, xen_acpi_processor_resume_worker);
 503
 504         /*
 505          * xen_upload_processor_pm_data() calls non-atomic code.
 506          * However, the context for xen_acpi_processor_resume is syscore
 507          * with only the boot CPU online and in an atomic context.
 508          *
 509          * So defer the upload for some point safer.
 510          */
 511         schedule_work(&wq);
 512 }
 513
 514 static struct syscore_ops xap_syscore_ops = {
 515         .resume = xen_acpi_processor_resume,
 516 };
 517
 518 static int __init xen_acpi_processor_init(void)
 519 {
 520         unsigned int i;
 521         int rc;
 522
 523         if (!xen_initial_domain())
 524                 return -ENODEV;
 525
 526         nr_acpi_bits = get_max_acpi_id() + 1;
 527         acpi_ids_done = bitmap_zalloc(nr_acpi_bits, GFP_KERNEL);
 528         if (!acpi_ids_done)
 529                 return -ENOMEM;
 530
 531         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
 532         if (!acpi_perf_data) {
 533                 pr_debug("Memory allocation error for acpi_perf_data\n");
 534                 bitmap_free(acpi_ids_done);
 535                 return -ENOMEM;
 536         }
 537         for_each_possible_cpu(i) {
 538                 if (!zalloc_cpumask_var_node(
 539                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
 540                         GFP_KERNEL, cpu_to_node(i))) {
 541                         rc = -ENOMEM;
 542                         goto err_out;
 543                 }
 544         }
 545
 546         /* Do initialization in ACPI core. It is OK to fail here. */
 547         (void)acpi_processor_preregister_performance(acpi_perf_data);
 548
 549         for_each_possible_cpu(i) {
 550                 struct acpi_processor *pr;
 551                 struct acpi_processor_performance *perf;
 552
 553                 pr = per_cpu(processors, i);
 554                 perf = per_cpu_ptr(acpi_perf_data, i);
 555                 if (!pr)
 556                         continue;
 557
 558                 pr->performance = perf;
 559                 rc = acpi_processor_get_performance_info(pr);
 560                 if (rc)
 561                         goto err_out;
 562         }
 563
 564         rc = xen_upload_processor_pm_data();
 565         if (rc)
 566                 goto err_unregister;
 567
 568         register_syscore_ops(&xap_syscore_ops);
 569
 570         return 0;
 571 err_unregister:
 572         for_each_possible_cpu(i)
 573                 acpi_processor_unregister_performance(i);
 574
 575 err_out:
 576         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
 577         free_acpi_perf_data();
 578         bitmap_free(acpi_ids_done);
 579         return rc;
 580 }
 581 static void __exit xen_acpi_processor_exit(void)
 582 {
 583         int i;
 584
 585         unregister_syscore_ops(&xap_syscore_ops);
 586         bitmap_free(acpi_ids_done);
 587         bitmap_free(acpi_id_present);
 588         bitmap_free(acpi_id_cst_present);
 589         kfree(acpi_psd);
 590         for_each_possible_cpu(i)
 591                 acpi_processor_unregister_performance(i);
 592
 593         free_acpi_perf_data();
 594 }
 595
 596 MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
 597 MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor");
 598 MODULE_LICENSE("GPL");
 599
 600 /* We want to be loaded before the CPU freq scaling drivers are loaded.
 601  * They are loaded in late_initcall. */
 602 device_initcall(xen_acpi_processor_init);
 603 module_exit(xen_acpi_processor_exit);