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 38 static int no_hypercall; 39 MODULE_PARM_DESC(off, "Inhibit the hypercall."); 40 module_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 */ 48 static unsigned int nr_acpi_bits; 49 /* Mutex to protect the acpi_ids_done - for CPU hotplug use. */ 50 static DEFINE_MUTEX(acpi_ids_mutex); 51 /* Which ACPI ID we have processed from 'struct acpi_processor'. */ 52 static unsigned long *acpi_ids_done; 53 /* Which ACPI ID exist in the SSDT/DSDT processor definitions. */ 54 static unsigned long __initdata *acpi_id_present; 55 /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */ 56 static unsigned long __initdata *acpi_id_cst_present; 57 58 static 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 } 143 static struct xen_processor_px * 144 xen_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 } 166 static 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 } 196 static 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 } 212 static 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); 270 err_free: 271 if (!IS_ERR_OR_NULL(dst_states)) 272 kfree(dst_states); 273 274 return ret; 275 } 276 static 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 } 294 static 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 */ 333 static acpi_status __init 334 read_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 } 388 static 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 } 427 static 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. */ 458 static struct acpi_processor_performance __percpu *acpi_perf_data; 459 460 static 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 } 470 471 static 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 if (pr_backup) 524 memcpy(pr_backup, _pr, sizeof(struct acpi_processor)); 525 } 526 (void)upload_pm_data(_pr); 527 } 528 rc = check_acpi_ids(pr_backup); 529 530 kfree(pr_backup); 531 pr_backup = NULL; 532 533 if (rc) 534 goto err_unregister; 535 536 return 0; 537 err_unregister: 538 for_each_possible_cpu(i) { 539 struct acpi_processor_performance *perf; 540 perf = per_cpu_ptr(acpi_perf_data, i); 541 acpi_processor_unregister_performance(perf, i); 542 } 543 err_out: 544 /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */ 545 free_acpi_perf_data(); 546 kfree(acpi_ids_done); 547 return rc; 548 } 549 static void __exit xen_acpi_processor_exit(void) 550 { 551 int i; 552 553 kfree(acpi_ids_done); 554 for_each_possible_cpu(i) { 555 struct acpi_processor_performance *perf; 556 perf = per_cpu_ptr(acpi_perf_data, i); 557 acpi_processor_unregister_performance(perf, i); 558 } 559 free_acpi_perf_data(); 560 } 561 562 MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>"); 563 MODULE_DESCRIPTION("Xen ACPI Processor P-states (and Cx) driver which uploads PM data to Xen hypervisor"); 564 MODULE_LICENSE("GPL"); 565 566 /* We want to be loaded before the CPU freq scaling drivers are loaded. 567 * They are loaded in late_initcall. */ 568 device_initcall(xen_acpi_processor_init); 569 module_exit(xen_acpi_processor_exit); 570