arch/powerpc/platforms/powernv/setup.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * PowerNV setup code.
   4  *
   5  * Copyright 2011 IBM Corp.
   6  */
   7
   8 #undef DEBUG
   9
  10 #include <linux/cpu.h>
  11 #include <linux/errno.h>
  12 #include <linux/sched.h>
  13 #include <linux/kernel.h>
  14 #include <linux/tty.h>
  15 #include <linux/reboot.h>
  16 #include <linux/init.h>
  17 #include <linux/console.h>
  18 #include <linux/delay.h>
  19 #include <linux/irq.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/of.h>
  22 #include <linux/of_fdt.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/bug.h>
  25 #include <linux/pci.h>
  26 #include <linux/cpufreq.h>
  27 #include <linux/memblock.h>
  28
  29 #include <asm/machdep.h>
  30 #include <asm/firmware.h>
  31 #include <asm/xics.h>
  32 #include <asm/xive.h>
  33 #include <asm/opal.h>
  34 #include <asm/kexec.h>
  35 #include <asm/smp.h>
  36 #include <asm/tm.h>
  37 #include <asm/setup.h>
  38 #include <asm/security_features.h>
  39
  40 #include "powernv.h"
  41
  42
  43 static bool __init fw_feature_is(const char *state, const char *name,
  44                           struct device_node *fw_features)
  45 {
  46         struct device_node *np;
  47         bool rc = false;
  48
  49         np = of_get_child_by_name(fw_features, name);
  50         if (np) {
  51                 rc = of_property_read_bool(np, state);
  52                 of_node_put(np);
  53         }
  54
  55         return rc;
  56 }
  57
  58 static void __init init_fw_feat_flags(struct device_node *np)
  59 {
  60         if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np))
  61                 security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
  62
  63         if (fw_feature_is("enabled", "fw-bcctrl-serialized", np))
  64                 security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
  65
  66         if (fw_feature_is("enabled", "inst-l1d-flush-ori30,30,0", np))
  67                 security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
  68
  69         if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np))
  70                 security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
  71
  72         if (fw_feature_is("enabled", "fw-l1d-thread-split", np))
  73                 security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
  74
  75         if (fw_feature_is("enabled", "fw-count-cache-disabled", np))
  76                 security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
  77
  78         if (fw_feature_is("enabled", "fw-count-cache-flush-bcctr2,0,0", np))
  79                 security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST);
  80
  81         if (fw_feature_is("enabled", "needs-count-cache-flush-on-context-switch", np))
  82                 security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE);
  83
  84         /*
  85          * The features below are enabled by default, so we instead look to see
  86          * if firmware has *disabled* them, and clear them if so.
  87          */
  88         if (fw_feature_is("disabled", "speculation-policy-favor-security", np))
  89                 security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
  90
  91         if (fw_feature_is("disabled", "needs-l1d-flush-msr-pr-0-to-1", np))
  92                 security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
  93
  94         if (fw_feature_is("disabled", "needs-l1d-flush-msr-hv-1-to-0", np))
  95                 security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
  96
  97         if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np))
  98                 security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
  99
 100         if (fw_feature_is("enabled", "no-need-l1d-flush-msr-pr-1-to-0", np))
 101                 security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
 102
 103         if (fw_feature_is("enabled", "no-need-l1d-flush-kernel-on-user-access", np))
 104                 security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
 105
 106         if (fw_feature_is("enabled", "no-need-store-drain-on-priv-state-switch", np))
 107                 security_ftr_clear(SEC_FTR_STF_BARRIER);
 108 }
 109
 110 static void __init pnv_setup_security_mitigations(void)
 111 {
 112         struct device_node *np, *fw_features;
 113         enum l1d_flush_type type;
 114         bool enable;
 115
 116         /* Default to fallback in case fw-features are not available */
 117         type = L1D_FLUSH_FALLBACK;
 118
 119         np = of_find_node_by_name(NULL, "ibm,opal");
 120         fw_features = of_get_child_by_name(np, "fw-features");
 121         of_node_put(np);
 122
 123         if (fw_features) {
 124                 init_fw_feat_flags(fw_features);
 125                 of_node_put(fw_features);
 126
 127                 if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
 128                         type = L1D_FLUSH_MTTRIG;
 129
 130                 if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
 131                         type = L1D_FLUSH_ORI;
 132         }
 133
 134         /*
 135          * The issues addressed by the entry and uaccess flush don't affect P7
 136          * or P8, so on bare metal disable them explicitly in case firmware does
 137          * not include the features to disable them. POWER9 and newer processors
 138          * should have the appropriate firmware flags.
 139          */
 140         if (pvr_version_is(PVR_POWER7) || pvr_version_is(PVR_POWER7p) ||
 141             pvr_version_is(PVR_POWER8E) || pvr_version_is(PVR_POWER8NVL) ||
 142             pvr_version_is(PVR_POWER8)) {
 143                 security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
 144                 security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
 145         }
 146
 147         enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
 148                  (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
 149                   security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
 150
 151         setup_rfi_flush(type, enable);
 152         setup_count_cache_flush();
 153
 154         enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 155                  security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
 156         setup_entry_flush(enable);
 157
 158         enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
 159                  security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
 160         setup_uaccess_flush(enable);
 161
 162         setup_stf_barrier();
 163 }
 164
 165 static void __init pnv_check_guarded_cores(void)
 166 {
 167         struct device_node *dn;
 168         int bad_count = 0;
 169
 170         for_each_node_by_type(dn, "cpu") {
 171                 if (of_property_match_string(dn, "status", "bad") >= 0)
 172                         bad_count++;
 173         }
 174
 175         if (bad_count) {
 176                 printk("  _     _______________\n");
 177                 pr_cont(" | |   /               \\\n");
 178                 pr_cont(" | |   |    WARNING!   |\n");
 179                 pr_cont(" | |   |               |\n");
 180                 pr_cont(" | |   | It looks like |\n");
 181                 pr_cont(" |_|   |  you have %*d |\n", 3, bad_count);
 182                 pr_cont("  _    | guarded cores |\n");
 183                 pr_cont(" (_)   \\_______________/\n");
 184         }
 185 }
 186
 187 static void __init pnv_setup_arch(void)
 188 {
 189         set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
 190
 191         pnv_setup_security_mitigations();
 192
 193         /* Initialize SMP */
 194         pnv_smp_init();
 195
 196         /* Setup RTC and NVRAM callbacks */
 197         if (firmware_has_feature(FW_FEATURE_OPAL))
 198                 opal_nvram_init();
 199
 200         /* Enable NAP mode */
 201         powersave_nap = 1;
 202
 203         pnv_check_guarded_cores();
 204
 205         /* XXX PMCS */
 206 }
 207
 208 static void __init pnv_init(void)
 209 {
 210         /*
 211          * Initialize the LPC bus now so that legacy serial
 212          * ports can be found on it
 213          */
 214         opal_lpc_init();
 215
 216 #ifdef CONFIG_HVC_OPAL
 217         if (firmware_has_feature(FW_FEATURE_OPAL))
 218                 hvc_opal_init_early();
 219         else
 220 #endif
 221                 add_preferred_console("hvc", 0, NULL);
 222
 223 #ifdef CONFIG_PPC_64S_HASH_MMU
 224         if (!radix_enabled()) {
 225                 size_t size = sizeof(struct slb_entry) * mmu_slb_size;
 226                 int i;
 227
 228                 /* Allocate per cpu area to save old slb contents during MCE */
 229                 for_each_possible_cpu(i) {
 230                         paca_ptrs[i]->mce_faulty_slbs =
 231                                         memblock_alloc_node(size,
 232                                                 __alignof__(struct slb_entry),
 233                                                 cpu_to_node(i));
 234                 }
 235         }
 236 #endif
 237 }
 238
 239 static void __init pnv_init_IRQ(void)
 240 {
 241         /* Try using a XIVE if available, otherwise use a XICS */
 242         if (!xive_native_init())
 243                 xics_init();
 244
 245         WARN_ON(!ppc_md.get_irq);
 246 }
 247
 248 static void pnv_show_cpuinfo(struct seq_file *m)
 249 {
 250         struct device_node *root;
 251         const char *model = "";
 252
 253         root = of_find_node_by_path("/");
 254         if (root)
 255                 model = of_get_property(root, "model", NULL);
 256         seq_printf(m, "machine\t\t: PowerNV %s\n", model);
 257         if (firmware_has_feature(FW_FEATURE_OPAL))
 258                 seq_printf(m, "firmware\t: OPAL\n");
 259         else
 260                 seq_printf(m, "firmware\t: BML\n");
 261         of_node_put(root);
 262         if (radix_enabled())
 263                 seq_printf(m, "MMU\t\t: Radix\n");
 264         else
 265                 seq_printf(m, "MMU\t\t: Hash\n");
 266 }
 267
 268 static void pnv_prepare_going_down(void)
 269 {
 270         /*
 271          * Disable all notifiers from OPAL, we can't
 272          * service interrupts anymore anyway
 273          */
 274         opal_event_shutdown();
 275
 276         /* Print flash update message if one is scheduled. */
 277         opal_flash_update_print_message();
 278
 279         smp_send_stop();
 280
 281         hard_irq_disable();
 282 }
 283
 284 static void  __noreturn pnv_restart(char *cmd)
 285 {
 286         long rc;
 287
 288         pnv_prepare_going_down();
 289
 290         do {
 291                 if (!cmd || !strlen(cmd))
 292                         rc = opal_cec_reboot();
 293                 else if (strcmp(cmd, "full") == 0)
 294                         rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
 295                 else if (strcmp(cmd, "mpipl") == 0)
 296                         rc = opal_cec_reboot2(OPAL_REBOOT_MPIPL, NULL);
 297                 else if (strcmp(cmd, "error") == 0)
 298                         rc = opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR, NULL);
 299                 else if (strcmp(cmd, "fast") == 0)
 300                         rc = opal_cec_reboot2(OPAL_REBOOT_FAST, NULL);
 301                 else
 302                         rc = OPAL_UNSUPPORTED;
 303
 304                 if (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 305                         /* Opal is busy wait for some time and retry */
 306                         opal_poll_events(NULL);
 307                         mdelay(10);
 308
 309                 } else  if (cmd && rc) {
 310                         /* Unknown error while issuing reboot */
 311                         if (rc == OPAL_UNSUPPORTED)
 312                                 pr_err("Unsupported '%s' reboot.\n", cmd);
 313                         else
 314                                 pr_err("Unable to issue '%s' reboot. Err=%ld\n",
 315                                        cmd, rc);
 316                         pr_info("Forcing a cec-reboot\n");
 317                         cmd = NULL;
 318                         rc = OPAL_BUSY;
 319
 320                 } else if (rc != OPAL_SUCCESS) {
 321                         /* Unknown error while issuing cec-reboot */
 322                         pr_err("Unable to reboot. Err=%ld\n", rc);
 323                 }
 324
 325         } while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT);
 326
 327         for (;;)
 328                 opal_poll_events(NULL);
 329 }
 330
 331 static void __noreturn pnv_power_off(void)
 332 {
 333         long rc = OPAL_BUSY;
 334
 335         pnv_prepare_going_down();
 336
 337         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 338                 rc = opal_cec_power_down(0);
 339                 if (rc == OPAL_BUSY_EVENT)
 340                         opal_poll_events(NULL);
 341                 else
 342                         mdelay(10);
 343         }
 344         for (;;)
 345                 opal_poll_events(NULL);
 346 }
 347
 348 static void __noreturn pnv_halt(void)
 349 {
 350         pnv_power_off();
 351 }
 352
 353 static void pnv_progress(char *s, unsigned short hex)
 354 {
 355 }
 356
 357 static void pnv_shutdown(void)
 358 {
 359         /* Let the PCI code clear up IODA tables */
 360         pnv_pci_shutdown();
 361
 362         /*
 363          * Stop OPAL activity: Unregister all OPAL interrupts so they
 364          * don't fire up while we kexec and make sure all potentially
 365          * DMA'ing ops are complete (such as dump retrieval).
 366          */
 367         opal_shutdown();
 368 }
 369
 370 #ifdef CONFIG_KEXEC_CORE
 371 static void pnv_kexec_wait_secondaries_down(void)
 372 {
 373         int my_cpu, i, notified = -1;
 374
 375         my_cpu = get_cpu();
 376
 377         for_each_online_cpu(i) {
 378                 uint8_t status;
 379                 int64_t rc, timeout = 1000;
 380
 381                 if (i == my_cpu)
 382                         continue;
 383
 384                 for (;;) {
 385                         rc = opal_query_cpu_status(get_hard_smp_processor_id(i),
 386                                                    &status);
 387                         if (rc != OPAL_SUCCESS || status != OPAL_THREAD_STARTED)
 388                                 break;
 389                         barrier();
 390                         if (i != notified) {
 391                                 printk(KERN_INFO "kexec: waiting for cpu %d "
 392                                        "(physical %d) to enter OPAL\n",
 393                                        i, paca_ptrs[i]->hw_cpu_id);
 394                                 notified = i;
 395                         }
 396
 397                         /*
 398                          * On crash secondaries might be unreachable or hung,
 399                          * so timeout if we've waited too long
 400                          * */
 401                         mdelay(1);
 402                         if (timeout-- == 0) {
 403                                 printk(KERN_ERR "kexec: timed out waiting for "
 404                                        "cpu %d (physical %d) to enter OPAL\n",
 405                                        i, paca_ptrs[i]->hw_cpu_id);
 406                                 break;
 407                         }
 408                 }
 409         }
 410 }
 411
 412 static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
 413 {
 414         u64 reinit_flags;
 415
 416         if (xive_enabled())
 417                 xive_teardown_cpu();
 418         else
 419                 xics_kexec_teardown_cpu(secondary);
 420
 421         /* On OPAL, we return all CPUs to firmware */
 422         if (!firmware_has_feature(FW_FEATURE_OPAL))
 423                 return;
 424
 425         if (secondary) {
 426                 /* Return secondary CPUs to firmware on OPAL v3 */
 427                 mb();
 428                 get_paca()->kexec_state = KEXEC_STATE_REAL_MODE;
 429                 mb();
 430
 431                 /* Return the CPU to OPAL */
 432                 opal_return_cpu();
 433         } else {
 434                 /* Primary waits for the secondaries to have reached OPAL */
 435                 pnv_kexec_wait_secondaries_down();
 436
 437                 /* Switch XIVE back to emulation mode */
 438                 if (xive_enabled())
 439                         xive_shutdown();
 440
 441                 /*
 442                  * We might be running as little-endian - now that interrupts
 443                  * are disabled, reset the HILE bit to big-endian so we don't
 444                  * take interrupts in the wrong endian later
 445                  *
 446                  * We reinit to enable both radix and hash on P9 to ensure
 447                  * the mode used by the next kernel is always supported.
 448                  */
 449                 reinit_flags = OPAL_REINIT_CPUS_HILE_BE;
 450                 if (cpu_has_feature(CPU_FTR_ARCH_300))
 451                         reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX |
 452                                 OPAL_REINIT_CPUS_MMU_HASH;
 453                 opal_reinit_cpus(reinit_flags);
 454         }
 455 }
 456 #endif /* CONFIG_KEXEC_CORE */
 457
 458 #ifdef CONFIG_MEMORY_HOTPLUG
 459 static unsigned long pnv_memory_block_size(void)
 460 {
 461         /*
 462          * We map the kernel linear region with 1GB large pages on radix. For
 463          * memory hot unplug to work our memory block size must be at least
 464          * this size.
 465          */
 466         if (radix_enabled())
 467                 return radix_mem_block_size;
 468         else
 469                 return 256UL * 1024 * 1024;
 470 }
 471 #endif
 472
 473 static void __init pnv_setup_machdep_opal(void)
 474 {
 475         ppc_md.get_boot_time = opal_get_boot_time;
 476         ppc_md.restart = pnv_restart;
 477         pm_power_off = pnv_power_off;
 478         ppc_md.halt = pnv_halt;
 479         /* ppc_md.system_reset_exception gets filled in by pnv_smp_init() */
 480         ppc_md.machine_check_exception = opal_machine_check;
 481         ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
 482         if (opal_check_token(OPAL_HANDLE_HMI2))
 483                 ppc_md.hmi_exception_early = opal_hmi_exception_early2;
 484         else
 485                 ppc_md.hmi_exception_early = opal_hmi_exception_early;
 486         ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
 487 }
 488
 489 static int __init pnv_probe(void)
 490 {
 491         if (!of_machine_is_compatible("ibm,powernv"))
 492                 return 0;
 493
 494         if (firmware_has_feature(FW_FEATURE_OPAL))
 495                 pnv_setup_machdep_opal();
 496
 497         pr_debug("PowerNV detected !\n");
 498
 499         pnv_init();
 500
 501         return 1;
 502 }
 503
 504 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 505 void __init pnv_tm_init(void)
 506 {
 507         if (!firmware_has_feature(FW_FEATURE_OPAL) ||
 508             !pvr_version_is(PVR_POWER9) ||
 509             early_cpu_has_feature(CPU_FTR_TM))
 510                 return;
 511
 512         if (opal_reinit_cpus(OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED) != OPAL_SUCCESS)
 513                 return;
 514
 515         pr_info("Enabling TM (Transactional Memory) with Suspend Disabled\n");
 516         cur_cpu_spec->cpu_features |= CPU_FTR_TM;
 517         /* Make sure "normal" HTM is off (it should be) */
 518         cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_HTM;
 519         /* Turn on no suspend mode, and HTM no SC */
 520         cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NO_SUSPEND | \
 521                                             PPC_FEATURE2_HTM_NOSC;
 522         tm_suspend_disabled = true;
 523 }
 524 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 525
 526 /*
 527  * Returns the cpu frequency for 'cpu' in Hz. This is used by
 528  * /proc/cpuinfo
 529  */
 530 static unsigned long pnv_get_proc_freq(unsigned int cpu)
 531 {
 532         unsigned long ret_freq;
 533
 534         ret_freq = cpufreq_get(cpu) * 1000ul;
 535
 536         /*
 537          * If the backend cpufreq driver does not exist,
 538          * then fallback to old way of reporting the clockrate.
 539          */
 540         if (!ret_freq)
 541                 ret_freq = ppc_proc_freq;
 542         return ret_freq;
 543 }
 544
 545 static long pnv_machine_check_early(struct pt_regs *regs)
 546 {
 547         long handled = 0;
 548
 549         if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
 550                 handled = cur_cpu_spec->machine_check_early(regs);
 551
 552         return handled;
 553 }
 554
 555 define_machine(powernv) {
 556         .name                   = "PowerNV",
 557         .probe                  = pnv_probe,
 558         .setup_arch             = pnv_setup_arch,
 559         .init_IRQ               = pnv_init_IRQ,
 560         .show_cpuinfo           = pnv_show_cpuinfo,
 561         .get_proc_freq          = pnv_get_proc_freq,
 562         .discover_phbs          = pnv_pci_init,
 563         .progress               = pnv_progress,
 564         .machine_shutdown       = pnv_shutdown,
 565         .power_save             = NULL,
 566         .calibrate_decr         = generic_calibrate_decr,
 567         .machine_check_early    = pnv_machine_check_early,
 568 #ifdef CONFIG_KEXEC_CORE
 569         .kexec_cpu_down         = pnv_kexec_cpu_down,
 570 #endif
 571 #ifdef CONFIG_MEMORY_HOTPLUG
 572         .memory_block_size      = pnv_memory_block_size,
 573 #endif
 574 };