1 /* 2 * SGI NMI support routines 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 * Copyright (c) 2009-2013 Silicon Graphics, Inc. All Rights Reserved. 19 * Copyright (c) Mike Travis 20 */ 21 22 #include <linux/cpu.h> 23 #include <linux/delay.h> 24 #include <linux/kdb.h> 25 #include <linux/kexec.h> 26 #include <linux/kgdb.h> 27 #include <linux/module.h> 28 #include <linux/nmi.h> 29 #include <linux/sched.h> 30 #include <linux/slab.h> 31 32 #include <asm/apic.h> 33 #include <asm/current.h> 34 #include <asm/kdebug.h> 35 #include <asm/local64.h> 36 #include <asm/nmi.h> 37 #include <asm/traps.h> 38 #include <asm/uv/uv.h> 39 #include <asm/uv/uv_hub.h> 40 #include <asm/uv/uv_mmrs.h> 41 42 /* 43 * UV handler for NMI 44 * 45 * Handle system-wide NMI events generated by the global 'power nmi' command. 46 * 47 * Basic operation is to field the NMI interrupt on each cpu and wait 48 * until all cpus have arrived into the nmi handler. If some cpus do not 49 * make it into the handler, try and force them in with the IPI(NMI) signal. 50 * 51 * We also have to lessen UV Hub MMR accesses as much as possible as this 52 * disrupts the UV Hub's primary mission of directing NumaLink traffic and 53 * can cause system problems to occur. 54 * 55 * To do this we register our primary NMI notifier on the NMI_UNKNOWN 56 * chain. This reduces the number of false NMI calls when the perf 57 * tools are running which generate an enormous number of NMIs per 58 * second (~4M/s for 1024 cpu threads). Our secondary NMI handler is 59 * very short as it only checks that if it has been "pinged" with the 60 * IPI(NMI) signal as mentioned above, and does not read the UV Hub's MMR. 61 * 62 */ 63 64 static struct uv_hub_nmi_s **uv_hub_nmi_list; 65 66 DEFINE_PER_CPU(struct uv_cpu_nmi_s, uv_cpu_nmi); 67 EXPORT_PER_CPU_SYMBOL_GPL(uv_cpu_nmi); 68 69 static unsigned long nmi_mmr; 70 static unsigned long nmi_mmr_clear; 71 static unsigned long nmi_mmr_pending; 72 73 static atomic_t uv_in_nmi; 74 static atomic_t uv_nmi_cpu = ATOMIC_INIT(-1); 75 static atomic_t uv_nmi_cpus_in_nmi = ATOMIC_INIT(-1); 76 static atomic_t uv_nmi_slave_continue; 77 static cpumask_var_t uv_nmi_cpu_mask; 78 79 /* Values for uv_nmi_slave_continue */ 80 #define SLAVE_CLEAR 0 81 #define SLAVE_CONTINUE 1 82 #define SLAVE_EXIT 2 83 84 /* 85 * Default is all stack dumps go to the console and buffer. 86 * Lower level to send to log buffer only. 87 */ 88 static int uv_nmi_loglevel = CONSOLE_LOGLEVEL_DEFAULT; 89 module_param_named(dump_loglevel, uv_nmi_loglevel, int, 0644); 90 91 /* 92 * The following values show statistics on how perf events are affecting 93 * this system. 94 */ 95 static int param_get_local64(char *buffer, const struct kernel_param *kp) 96 { 97 return sprintf(buffer, "%lu\n", local64_read((local64_t *)kp->arg)); 98 } 99 100 static int param_set_local64(const char *val, const struct kernel_param *kp) 101 { 102 /* clear on any write */ 103 local64_set((local64_t *)kp->arg, 0); 104 return 0; 105 } 106 107 static struct kernel_param_ops param_ops_local64 = { 108 .get = param_get_local64, 109 .set = param_set_local64, 110 }; 111 #define param_check_local64(name, p) __param_check(name, p, local64_t) 112 113 static local64_t uv_nmi_count; 114 module_param_named(nmi_count, uv_nmi_count, local64, 0644); 115 116 static local64_t uv_nmi_misses; 117 module_param_named(nmi_misses, uv_nmi_misses, local64, 0644); 118 119 static local64_t uv_nmi_ping_count; 120 module_param_named(ping_count, uv_nmi_ping_count, local64, 0644); 121 122 static local64_t uv_nmi_ping_misses; 123 module_param_named(ping_misses, uv_nmi_ping_misses, local64, 0644); 124 125 /* 126 * Following values allow tuning for large systems under heavy loading 127 */ 128 static int uv_nmi_initial_delay = 100; 129 module_param_named(initial_delay, uv_nmi_initial_delay, int, 0644); 130 131 static int uv_nmi_slave_delay = 100; 132 module_param_named(slave_delay, uv_nmi_slave_delay, int, 0644); 133 134 static int uv_nmi_loop_delay = 100; 135 module_param_named(loop_delay, uv_nmi_loop_delay, int, 0644); 136 137 static int uv_nmi_trigger_delay = 10000; 138 module_param_named(trigger_delay, uv_nmi_trigger_delay, int, 0644); 139 140 static int uv_nmi_wait_count = 100; 141 module_param_named(wait_count, uv_nmi_wait_count, int, 0644); 142 143 static int uv_nmi_retry_count = 500; 144 module_param_named(retry_count, uv_nmi_retry_count, int, 0644); 145 146 /* 147 * Valid NMI Actions: 148 * "dump" - dump process stack for each cpu 149 * "ips" - dump IP info for each cpu 150 * "kdump" - do crash dump 151 * "kdb" - enter KDB (default) 152 * "kgdb" - enter KGDB 153 */ 154 static char uv_nmi_action[8] = "kdb"; 155 module_param_string(action, uv_nmi_action, sizeof(uv_nmi_action), 0644); 156 157 static inline bool uv_nmi_action_is(const char *action) 158 { 159 return (strncmp(uv_nmi_action, action, strlen(action)) == 0); 160 } 161 162 /* Setup which NMI support is present in system */ 163 static void uv_nmi_setup_mmrs(void) 164 { 165 if (uv_read_local_mmr(UVH_NMI_MMRX_SUPPORTED)) { 166 uv_write_local_mmr(UVH_NMI_MMRX_REQ, 167 1UL << UVH_NMI_MMRX_REQ_SHIFT); 168 nmi_mmr = UVH_NMI_MMRX; 169 nmi_mmr_clear = UVH_NMI_MMRX_CLEAR; 170 nmi_mmr_pending = 1UL << UVH_NMI_MMRX_SHIFT; 171 pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMRX_TYPE); 172 } else { 173 nmi_mmr = UVH_NMI_MMR; 174 nmi_mmr_clear = UVH_NMI_MMR_CLEAR; 175 nmi_mmr_pending = 1UL << UVH_NMI_MMR_SHIFT; 176 pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMR_TYPE); 177 } 178 } 179 180 /* Read NMI MMR and check if NMI flag was set by BMC. */ 181 static inline int uv_nmi_test_mmr(struct uv_hub_nmi_s *hub_nmi) 182 { 183 hub_nmi->nmi_value = uv_read_local_mmr(nmi_mmr); 184 atomic_inc(&hub_nmi->read_mmr_count); 185 return !!(hub_nmi->nmi_value & nmi_mmr_pending); 186 } 187 188 static inline void uv_local_mmr_clear_nmi(void) 189 { 190 uv_write_local_mmr(nmi_mmr_clear, nmi_mmr_pending); 191 } 192 193 /* 194 * If first cpu in on this hub, set hub_nmi "in_nmi" and "owner" values and 195 * return true. If first cpu in on the system, set global "in_nmi" flag. 196 */ 197 static int uv_set_in_nmi(int cpu, struct uv_hub_nmi_s *hub_nmi) 198 { 199 int first = atomic_add_unless(&hub_nmi->in_nmi, 1, 1); 200 201 if (first) { 202 atomic_set(&hub_nmi->cpu_owner, cpu); 203 if (atomic_add_unless(&uv_in_nmi, 1, 1)) 204 atomic_set(&uv_nmi_cpu, cpu); 205 206 atomic_inc(&hub_nmi->nmi_count); 207 } 208 return first; 209 } 210 211 /* Check if this is a system NMI event */ 212 static int uv_check_nmi(struct uv_hub_nmi_s *hub_nmi) 213 { 214 int cpu = smp_processor_id(); 215 int nmi = 0; 216 217 local64_inc(&uv_nmi_count); 218 this_cpu_inc(uv_cpu_nmi.queries); 219 220 do { 221 nmi = atomic_read(&hub_nmi->in_nmi); 222 if (nmi) 223 break; 224 225 if (raw_spin_trylock(&hub_nmi->nmi_lock)) { 226 227 /* check hub MMR NMI flag */ 228 if (uv_nmi_test_mmr(hub_nmi)) { 229 uv_set_in_nmi(cpu, hub_nmi); 230 nmi = 1; 231 break; 232 } 233 234 /* MMR NMI flag is clear */ 235 raw_spin_unlock(&hub_nmi->nmi_lock); 236 237 } else { 238 /* wait a moment for the hub nmi locker to set flag */ 239 cpu_relax(); 240 udelay(uv_nmi_slave_delay); 241 242 /* re-check hub in_nmi flag */ 243 nmi = atomic_read(&hub_nmi->in_nmi); 244 if (nmi) 245 break; 246 } 247 248 /* check if this BMC missed setting the MMR NMI flag */ 249 if (!nmi) { 250 nmi = atomic_read(&uv_in_nmi); 251 if (nmi) 252 uv_set_in_nmi(cpu, hub_nmi); 253 } 254 255 } while (0); 256 257 if (!nmi) 258 local64_inc(&uv_nmi_misses); 259 260 return nmi; 261 } 262 263 /* Need to reset the NMI MMR register, but only once per hub. */ 264 static inline void uv_clear_nmi(int cpu) 265 { 266 struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi; 267 268 if (cpu == atomic_read(&hub_nmi->cpu_owner)) { 269 atomic_set(&hub_nmi->cpu_owner, -1); 270 atomic_set(&hub_nmi->in_nmi, 0); 271 uv_local_mmr_clear_nmi(); 272 raw_spin_unlock(&hub_nmi->nmi_lock); 273 } 274 } 275 276 /* Print non-responding cpus */ 277 static void uv_nmi_nr_cpus_pr(char *fmt) 278 { 279 static char cpu_list[1024]; 280 int len = sizeof(cpu_list); 281 int c = cpumask_weight(uv_nmi_cpu_mask); 282 int n = cpulist_scnprintf(cpu_list, len, uv_nmi_cpu_mask); 283 284 if (n >= len-1) 285 strcpy(&cpu_list[len - 6], "...\n"); 286 287 printk(fmt, c, cpu_list); 288 } 289 290 /* Ping non-responding cpus attemping to force them into the NMI handler */ 291 static void uv_nmi_nr_cpus_ping(void) 292 { 293 int cpu; 294 295 for_each_cpu(cpu, uv_nmi_cpu_mask) 296 uv_cpu_nmi_per(cpu).pinging = 1; 297 298 apic->send_IPI_mask(uv_nmi_cpu_mask, APIC_DM_NMI); 299 } 300 301 /* Clean up flags for cpus that ignored both NMI and ping */ 302 static void uv_nmi_cleanup_mask(void) 303 { 304 int cpu; 305 306 for_each_cpu(cpu, uv_nmi_cpu_mask) { 307 uv_cpu_nmi_per(cpu).pinging = 0; 308 uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_OUT; 309 cpumask_clear_cpu(cpu, uv_nmi_cpu_mask); 310 } 311 } 312 313 /* Loop waiting as cpus enter nmi handler */ 314 static int uv_nmi_wait_cpus(int first) 315 { 316 int i, j, k, n = num_online_cpus(); 317 int last_k = 0, waiting = 0; 318 319 if (first) { 320 cpumask_copy(uv_nmi_cpu_mask, cpu_online_mask); 321 k = 0; 322 } else { 323 k = n - cpumask_weight(uv_nmi_cpu_mask); 324 } 325 326 udelay(uv_nmi_initial_delay); 327 for (i = 0; i < uv_nmi_retry_count; i++) { 328 int loop_delay = uv_nmi_loop_delay; 329 330 for_each_cpu(j, uv_nmi_cpu_mask) { 331 if (uv_cpu_nmi_per(j).state) { 332 cpumask_clear_cpu(j, uv_nmi_cpu_mask); 333 if (++k >= n) 334 break; 335 } 336 } 337 if (k >= n) { /* all in? */ 338 k = n; 339 break; 340 } 341 if (last_k != k) { /* abort if no new cpus coming in */ 342 last_k = k; 343 waiting = 0; 344 } else if (++waiting > uv_nmi_wait_count) 345 break; 346 347 /* extend delay if waiting only for cpu 0 */ 348 if (waiting && (n - k) == 1 && 349 cpumask_test_cpu(0, uv_nmi_cpu_mask)) 350 loop_delay *= 100; 351 352 udelay(loop_delay); 353 } 354 atomic_set(&uv_nmi_cpus_in_nmi, k); 355 return n - k; 356 } 357 358 /* Wait until all slave cpus have entered UV NMI handler */ 359 static void uv_nmi_wait(int master) 360 { 361 /* indicate this cpu is in */ 362 this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_IN); 363 364 /* if not the first cpu in (the master), then we are a slave cpu */ 365 if (!master) 366 return; 367 368 do { 369 /* wait for all other cpus to gather here */ 370 if (!uv_nmi_wait_cpus(1)) 371 break; 372 373 /* if not all made it in, send IPI NMI to them */ 374 uv_nmi_nr_cpus_pr(KERN_ALERT 375 "UV: Sending NMI IPI to %d non-responding CPUs: %s\n"); 376 uv_nmi_nr_cpus_ping(); 377 378 /* if all cpus are in, then done */ 379 if (!uv_nmi_wait_cpus(0)) 380 break; 381 382 uv_nmi_nr_cpus_pr(KERN_ALERT 383 "UV: %d CPUs not in NMI loop: %s\n"); 384 } while (0); 385 386 pr_alert("UV: %d of %d CPUs in NMI\n", 387 atomic_read(&uv_nmi_cpus_in_nmi), num_online_cpus()); 388 } 389 390 static void uv_nmi_dump_cpu_ip_hdr(void) 391 { 392 printk(KERN_DEFAULT 393 "\nUV: %4s %6s %-32s %s (Note: PID 0 not listed)\n", 394 "CPU", "PID", "COMMAND", "IP"); 395 } 396 397 static void uv_nmi_dump_cpu_ip(int cpu, struct pt_regs *regs) 398 { 399 printk(KERN_DEFAULT "UV: %4d %6d %-32.32s ", 400 cpu, current->pid, current->comm); 401 402 printk_address(regs->ip); 403 } 404 405 /* Dump this cpu's state */ 406 static void uv_nmi_dump_state_cpu(int cpu, struct pt_regs *regs) 407 { 408 const char *dots = " ................................. "; 409 410 if (uv_nmi_action_is("ips")) { 411 if (cpu == 0) 412 uv_nmi_dump_cpu_ip_hdr(); 413 414 if (current->pid != 0) 415 uv_nmi_dump_cpu_ip(cpu, regs); 416 417 } else if (uv_nmi_action_is("dump")) { 418 printk(KERN_DEFAULT 419 "UV:%sNMI process trace for CPU %d\n", dots, cpu); 420 show_regs(regs); 421 } 422 this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_DUMP_DONE); 423 } 424 425 /* Trigger a slave cpu to dump it's state */ 426 static void uv_nmi_trigger_dump(int cpu) 427 { 428 int retry = uv_nmi_trigger_delay; 429 430 if (uv_cpu_nmi_per(cpu).state != UV_NMI_STATE_IN) 431 return; 432 433 uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_DUMP; 434 do { 435 cpu_relax(); 436 udelay(10); 437 if (uv_cpu_nmi_per(cpu).state 438 != UV_NMI_STATE_DUMP) 439 return; 440 } while (--retry > 0); 441 442 pr_crit("UV: CPU %d stuck in process dump function\n", cpu); 443 uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_DUMP_DONE; 444 } 445 446 /* Wait until all cpus ready to exit */ 447 static void uv_nmi_sync_exit(int master) 448 { 449 atomic_dec(&uv_nmi_cpus_in_nmi); 450 if (master) { 451 while (atomic_read(&uv_nmi_cpus_in_nmi) > 0) 452 cpu_relax(); 453 atomic_set(&uv_nmi_slave_continue, SLAVE_CLEAR); 454 } else { 455 while (atomic_read(&uv_nmi_slave_continue)) 456 cpu_relax(); 457 } 458 } 459 460 /* Walk through cpu list and dump state of each */ 461 static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master) 462 { 463 if (master) { 464 int tcpu; 465 int ignored = 0; 466 int saved_console_loglevel = console_loglevel; 467 468 pr_alert("UV: tracing %s for %d CPUs from CPU %d\n", 469 uv_nmi_action_is("ips") ? "IPs" : "processes", 470 atomic_read(&uv_nmi_cpus_in_nmi), cpu); 471 472 console_loglevel = uv_nmi_loglevel; 473 atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); 474 for_each_online_cpu(tcpu) { 475 if (cpumask_test_cpu(tcpu, uv_nmi_cpu_mask)) 476 ignored++; 477 else if (tcpu == cpu) 478 uv_nmi_dump_state_cpu(tcpu, regs); 479 else 480 uv_nmi_trigger_dump(tcpu); 481 } 482 if (ignored) 483 printk(KERN_DEFAULT "UV: %d CPUs ignored NMI\n", 484 ignored); 485 486 console_loglevel = saved_console_loglevel; 487 pr_alert("UV: process trace complete\n"); 488 } else { 489 while (!atomic_read(&uv_nmi_slave_continue)) 490 cpu_relax(); 491 while (this_cpu_read(uv_cpu_nmi.state) != UV_NMI_STATE_DUMP) 492 cpu_relax(); 493 uv_nmi_dump_state_cpu(cpu, regs); 494 } 495 uv_nmi_sync_exit(master); 496 } 497 498 static void uv_nmi_touch_watchdogs(void) 499 { 500 touch_softlockup_watchdog_sync(); 501 clocksource_touch_watchdog(); 502 rcu_cpu_stall_reset(); 503 touch_nmi_watchdog(); 504 } 505 506 #if defined(CONFIG_KEXEC) 507 static atomic_t uv_nmi_kexec_failed; 508 static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs) 509 { 510 /* Call crash to dump system state */ 511 if (master) { 512 pr_emerg("UV: NMI executing crash_kexec on CPU%d\n", cpu); 513 crash_kexec(regs); 514 515 pr_emerg("UV: crash_kexec unexpectedly returned, "); 516 if (!kexec_crash_image) { 517 pr_cont("crash kernel not loaded\n"); 518 atomic_set(&uv_nmi_kexec_failed, 1); 519 uv_nmi_sync_exit(1); 520 return; 521 } 522 pr_cont("kexec busy, stalling cpus while waiting\n"); 523 } 524 525 /* If crash exec fails the slaves should return, otherwise stall */ 526 while (atomic_read(&uv_nmi_kexec_failed) == 0) 527 mdelay(10); 528 529 /* Crash kernel most likely not loaded, return in an orderly fashion */ 530 uv_nmi_sync_exit(0); 531 } 532 533 #else /* !CONFIG_KEXEC */ 534 static inline void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs) 535 { 536 if (master) 537 pr_err("UV: NMI kdump: KEXEC not supported in this kernel\n"); 538 } 539 #endif /* !CONFIG_KEXEC */ 540 541 #ifdef CONFIG_KGDB 542 #ifdef CONFIG_KGDB_KDB 543 static inline int uv_nmi_kdb_reason(void) 544 { 545 return KDB_REASON_SYSTEM_NMI; 546 } 547 #else /* !CONFIG_KGDB_KDB */ 548 static inline int uv_nmi_kdb_reason(void) 549 { 550 /* Insure user is expecting to attach gdb remote */ 551 if (uv_nmi_action_is("kgdb")) 552 return 0; 553 554 pr_err("UV: NMI error: KDB is not enabled in this kernel\n"); 555 return -1; 556 } 557 #endif /* CONFIG_KGDB_KDB */ 558 559 /* 560 * Call KGDB/KDB from NMI handler 561 * 562 * Note that if both KGDB and KDB are configured, then the action of 'kgdb' or 563 * 'kdb' has no affect on which is used. See the KGDB documention for further 564 * information. 565 */ 566 static void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master) 567 { 568 if (master) { 569 int reason = uv_nmi_kdb_reason(); 570 int ret; 571 572 if (reason < 0) 573 return; 574 575 /* call KGDB NMI handler as MASTER */ 576 ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs, reason, 577 &uv_nmi_slave_continue); 578 if (ret) { 579 pr_alert("KGDB returned error, is kgdboc set?\n"); 580 atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); 581 } 582 } else { 583 /* wait for KGDB signal that it's ready for slaves to enter */ 584 int sig; 585 586 do { 587 cpu_relax(); 588 sig = atomic_read(&uv_nmi_slave_continue); 589 } while (!sig); 590 591 /* call KGDB as slave */ 592 if (sig == SLAVE_CONTINUE) 593 kgdb_nmicallback(cpu, regs); 594 } 595 uv_nmi_sync_exit(master); 596 } 597 598 #else /* !CONFIG_KGDB */ 599 static inline void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master) 600 { 601 pr_err("UV: NMI error: KGDB is not enabled in this kernel\n"); 602 } 603 #endif /* !CONFIG_KGDB */ 604 605 /* 606 * UV NMI handler 607 */ 608 int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) 609 { 610 struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi; 611 int cpu = smp_processor_id(); 612 int master = 0; 613 unsigned long flags; 614 615 local_irq_save(flags); 616 617 /* If not a UV System NMI, ignore */ 618 if (!this_cpu_read(uv_cpu_nmi.pinging) && !uv_check_nmi(hub_nmi)) { 619 local_irq_restore(flags); 620 return NMI_DONE; 621 } 622 623 /* Indicate we are the first CPU into the NMI handler */ 624 master = (atomic_read(&uv_nmi_cpu) == cpu); 625 626 /* If NMI action is "kdump", then attempt to do it */ 627 if (uv_nmi_action_is("kdump")) 628 uv_nmi_kdump(cpu, master, regs); 629 630 /* Pause as all cpus enter the NMI handler */ 631 uv_nmi_wait(master); 632 633 /* Dump state of each cpu */ 634 if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump")) 635 uv_nmi_dump_state(cpu, regs, master); 636 637 /* Call KGDB/KDB if enabled */ 638 else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb")) 639 uv_call_kgdb_kdb(cpu, regs, master); 640 641 /* Clear per_cpu "in nmi" flag */ 642 this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_OUT); 643 644 /* Clear MMR NMI flag on each hub */ 645 uv_clear_nmi(cpu); 646 647 /* Clear global flags */ 648 if (master) { 649 if (cpumask_weight(uv_nmi_cpu_mask)) 650 uv_nmi_cleanup_mask(); 651 atomic_set(&uv_nmi_cpus_in_nmi, -1); 652 atomic_set(&uv_nmi_cpu, -1); 653 atomic_set(&uv_in_nmi, 0); 654 } 655 656 uv_nmi_touch_watchdogs(); 657 local_irq_restore(flags); 658 659 return NMI_HANDLED; 660 } 661 662 /* 663 * NMI handler for pulling in CPUs when perf events are grabbing our NMI 664 */ 665 static int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs) 666 { 667 int ret; 668 669 this_cpu_inc(uv_cpu_nmi.queries); 670 if (!this_cpu_read(uv_cpu_nmi.pinging)) { 671 local64_inc(&uv_nmi_ping_misses); 672 return NMI_DONE; 673 } 674 675 this_cpu_inc(uv_cpu_nmi.pings); 676 local64_inc(&uv_nmi_ping_count); 677 ret = uv_handle_nmi(reason, regs); 678 this_cpu_write(uv_cpu_nmi.pinging, 0); 679 return ret; 680 } 681 682 static void uv_register_nmi_notifier(void) 683 { 684 if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv")) 685 pr_warn("UV: NMI handler failed to register\n"); 686 687 if (register_nmi_handler(NMI_LOCAL, uv_handle_nmi_ping, 0, "uvping")) 688 pr_warn("UV: PING NMI handler failed to register\n"); 689 } 690 691 void uv_nmi_init(void) 692 { 693 unsigned int value; 694 695 /* 696 * Unmask NMI on all cpus 697 */ 698 value = apic_read(APIC_LVT1) | APIC_DM_NMI; 699 value &= ~APIC_LVT_MASKED; 700 apic_write(APIC_LVT1, value); 701 } 702 703 void uv_nmi_setup(void) 704 { 705 int size = sizeof(void *) * (1 << NODES_SHIFT); 706 int cpu, nid; 707 708 /* Setup hub nmi info */ 709 uv_nmi_setup_mmrs(); 710 uv_hub_nmi_list = kzalloc(size, GFP_KERNEL); 711 pr_info("UV: NMI hub list @ 0x%p (%d)\n", uv_hub_nmi_list, size); 712 BUG_ON(!uv_hub_nmi_list); 713 size = sizeof(struct uv_hub_nmi_s); 714 for_each_present_cpu(cpu) { 715 nid = cpu_to_node(cpu); 716 if (uv_hub_nmi_list[nid] == NULL) { 717 uv_hub_nmi_list[nid] = kzalloc_node(size, 718 GFP_KERNEL, nid); 719 BUG_ON(!uv_hub_nmi_list[nid]); 720 raw_spin_lock_init(&(uv_hub_nmi_list[nid]->nmi_lock)); 721 atomic_set(&uv_hub_nmi_list[nid]->cpu_owner, -1); 722 } 723 uv_hub_nmi_per(cpu) = uv_hub_nmi_list[nid]; 724 } 725 BUG_ON(!alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL)); 726 uv_register_nmi_notifier(); 727 } 728