1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * SGI NMI support routines 4 * 5 * (C) Copyright 2020 Hewlett Packard Enterprise Development LP 6 * Copyright (C) 2007-2017 Silicon Graphics, Inc. All rights reserved. 7 * Copyright (c) Mike Travis 8 */ 9 10 #include <linux/cpu.h> 11 #include <linux/delay.h> 12 #include <linux/kdb.h> 13 #include <linux/kexec.h> 14 #include <linux/kgdb.h> 15 #include <linux/moduleparam.h> 16 #include <linux/nmi.h> 17 #include <linux/sched.h> 18 #include <linux/sched/debug.h> 19 #include <linux/slab.h> 20 #include <linux/string.h> 21 #include <linux/string_choices.h> 22 #include <linux/clocksource.h> 23 24 #include <asm/apic.h> 25 #include <asm/current.h> 26 #include <asm/kdebug.h> 27 #include <asm/local64.h> 28 #include <asm/nmi.h> 29 #include <asm/reboot.h> 30 #include <asm/traps.h> 31 #include <asm/uv/uv.h> 32 #include <asm/uv/uv_hub.h> 33 #include <asm/uv/uv_mmrs.h> 34 35 /* 36 * UV handler for NMI 37 * 38 * Handle system-wide NMI events generated by the global 'power nmi' command. 39 * 40 * Basic operation is to field the NMI interrupt on each CPU and wait 41 * until all CPU's have arrived into the nmi handler. If some CPU's do not 42 * make it into the handler, try and force them in with the IPI(NMI) signal. 43 * 44 * We also have to lessen UV Hub MMR accesses as much as possible as this 45 * disrupts the UV Hub's primary mission of directing NumaLink traffic and 46 * can cause system problems to occur. 47 * 48 * To do this we register our primary NMI notifier on the NMI_UNKNOWN 49 * chain. This reduces the number of false NMI calls when the perf 50 * tools are running which generate an enormous number of NMIs per 51 * second (~4M/s for 1024 CPU threads). Our secondary NMI handler is 52 * very short as it only checks that if it has been "pinged" with the 53 * IPI(NMI) signal as mentioned above, and does not read the UV Hub's MMR. 54 * 55 */ 56 57 static struct uv_hub_nmi_s **uv_hub_nmi_list; 58 59 DEFINE_PER_CPU(struct uv_cpu_nmi_s, uv_cpu_nmi); 60 61 /* Newer SMM NMI handler, not present in all systems */ 62 static unsigned long uvh_nmi_mmrx; /* UVH_EVENT_OCCURRED0/1 */ 63 static unsigned long uvh_nmi_mmrx_clear; /* UVH_EVENT_OCCURRED0/1_ALIAS */ 64 static int uvh_nmi_mmrx_shift; /* UVH_EVENT_OCCURRED0/1_EXTIO_INT0_SHFT */ 65 static char *uvh_nmi_mmrx_type; /* "EXTIO_INT0" */ 66 67 /* Non-zero indicates newer SMM NMI handler present */ 68 static unsigned long uvh_nmi_mmrx_supported; /* UVH_EXTIO_INT0_BROADCAST */ 69 70 /* Indicates to BIOS that we want to use the newer SMM NMI handler */ 71 static unsigned long uvh_nmi_mmrx_req; /* UVH_BIOS_KERNEL_MMR_ALIAS_2 */ 72 static int uvh_nmi_mmrx_req_shift; /* 62 */ 73 74 /* UV hubless values */ 75 #define NMI_CONTROL_PORT 0x70 76 #define NMI_DUMMY_PORT 0x71 77 #define PAD_OWN_GPP_D_0 0x2c 78 #define GPI_NMI_STS_GPP_D_0 0x164 79 #define GPI_NMI_ENA_GPP_D_0 0x174 80 #define STS_GPP_D_0_MASK 0x1 81 #define PAD_CFG_DW0_GPP_D_0 0x4c0 82 #define GPIROUTNMI (1ul << 17) 83 #define PCH_PCR_GPIO_1_BASE 0xfdae0000ul 84 #define PCH_PCR_GPIO_ADDRESS(offset) (int *)((u64)(pch_base) | (u64)(offset)) 85 86 static u64 *pch_base; 87 static unsigned long nmi_mmr; 88 static unsigned long nmi_mmr_clear; 89 static unsigned long nmi_mmr_pending; 90 91 static atomic_t uv_in_nmi; 92 static atomic_t uv_nmi_cpu = ATOMIC_INIT(-1); 93 static atomic_t uv_nmi_cpus_in_nmi = ATOMIC_INIT(-1); 94 static atomic_t uv_nmi_slave_continue; 95 static cpumask_var_t uv_nmi_cpu_mask; 96 97 static atomic_t uv_nmi_kexec_failed; 98 99 /* Values for uv_nmi_slave_continue */ 100 #define SLAVE_CLEAR 0 101 #define SLAVE_CONTINUE 1 102 #define SLAVE_EXIT 2 103 104 /* 105 * Default is all stack dumps go to the console and buffer. 106 * Lower level to send to log buffer only. 107 */ 108 static int uv_nmi_loglevel = CONSOLE_LOGLEVEL_DEFAULT; 109 module_param_named(dump_loglevel, uv_nmi_loglevel, int, 0644); 110 111 /* 112 * The following values show statistics on how perf events are affecting 113 * this system. 114 */ 115 static int param_get_local64(char *buffer, const struct kernel_param *kp) 116 { 117 return sprintf(buffer, "%lu\n", local64_read((local64_t *)kp->arg)); 118 } 119 120 static int param_set_local64(const char *val, const struct kernel_param *kp) 121 { 122 /* Clear on any write */ 123 local64_set((local64_t *)kp->arg, 0); 124 return 0; 125 } 126 127 static const struct kernel_param_ops param_ops_local64 = { 128 .get = param_get_local64, 129 .set = param_set_local64, 130 }; 131 #define param_check_local64(name, p) __param_check(name, p, local64_t) 132 133 static local64_t uv_nmi_count; 134 module_param_named(nmi_count, uv_nmi_count, local64, 0644); 135 136 static local64_t uv_nmi_misses; 137 module_param_named(nmi_misses, uv_nmi_misses, local64, 0644); 138 139 static local64_t uv_nmi_ping_count; 140 module_param_named(ping_count, uv_nmi_ping_count, local64, 0644); 141 142 static local64_t uv_nmi_ping_misses; 143 module_param_named(ping_misses, uv_nmi_ping_misses, local64, 0644); 144 145 /* 146 * Following values allow tuning for large systems under heavy loading 147 */ 148 static int uv_nmi_initial_delay = 100; 149 module_param_named(initial_delay, uv_nmi_initial_delay, int, 0644); 150 151 static int uv_nmi_slave_delay = 100; 152 module_param_named(slave_delay, uv_nmi_slave_delay, int, 0644); 153 154 static int uv_nmi_loop_delay = 100; 155 module_param_named(loop_delay, uv_nmi_loop_delay, int, 0644); 156 157 static int uv_nmi_trigger_delay = 10000; 158 module_param_named(trigger_delay, uv_nmi_trigger_delay, int, 0644); 159 160 static int uv_nmi_wait_count = 100; 161 module_param_named(wait_count, uv_nmi_wait_count, int, 0644); 162 163 static int uv_nmi_retry_count = 500; 164 module_param_named(retry_count, uv_nmi_retry_count, int, 0644); 165 166 static bool uv_pch_intr_enable = true; 167 static bool uv_pch_intr_now_enabled; 168 module_param_named(pch_intr_enable, uv_pch_intr_enable, bool, 0644); 169 170 static bool uv_pch_init_enable = true; 171 module_param_named(pch_init_enable, uv_pch_init_enable, bool, 0644); 172 173 static int uv_nmi_debug; 174 module_param_named(debug, uv_nmi_debug, int, 0644); 175 176 #define nmi_debug(fmt, ...) \ 177 do { \ 178 if (uv_nmi_debug) \ 179 pr_info(fmt, ##__VA_ARGS__); \ 180 } while (0) 181 182 /* Valid NMI Actions */ 183 enum action_t { 184 nmi_act_kdump, 185 nmi_act_dump, 186 nmi_act_ips, 187 nmi_act_kdb, 188 nmi_act_kgdb, 189 nmi_act_health, 190 nmi_act_max 191 }; 192 193 static const char * const actions[nmi_act_max] = { 194 [nmi_act_kdump] = "kdump", 195 [nmi_act_dump] = "dump", 196 [nmi_act_ips] = "ips", 197 [nmi_act_kdb] = "kdb", 198 [nmi_act_kgdb] = "kgdb", 199 [nmi_act_health] = "health", 200 }; 201 202 static const char * const actions_desc[nmi_act_max] = { 203 [nmi_act_kdump] = "do kernel crash dump", 204 [nmi_act_dump] = "dump process stack for each cpu", 205 [nmi_act_ips] = "dump Inst Ptr info for each cpu", 206 [nmi_act_kdb] = "enter KDB (needs kgdboc= assignment)", 207 [nmi_act_kgdb] = "enter KGDB (needs gdb target remote)", 208 [nmi_act_health] = "check if CPUs respond to NMI", 209 }; 210 211 static enum action_t uv_nmi_action = nmi_act_dump; 212 213 static int param_get_action(char *buffer, const struct kernel_param *kp) 214 { 215 return sprintf(buffer, "%s\n", actions[uv_nmi_action]); 216 } 217 218 static int param_set_action(const char *val, const struct kernel_param *kp) 219 { 220 int i, n = ARRAY_SIZE(actions); 221 222 i = sysfs_match_string(actions, val); 223 if (i >= 0) { 224 uv_nmi_action = i; 225 pr_info("UV: New NMI action:%s\n", actions[i]); 226 return 0; 227 } 228 229 pr_err("UV: Invalid NMI action. Valid actions are:\n"); 230 for (i = 0; i < n; i++) 231 pr_err("UV: %-8s - %s\n", actions[i], actions_desc[i]); 232 233 return -EINVAL; 234 } 235 236 static const struct kernel_param_ops param_ops_action = { 237 .get = param_get_action, 238 .set = param_set_action, 239 }; 240 #define param_check_action(name, p) __param_check(name, p, enum action_t) 241 242 module_param_named(action, uv_nmi_action, action, 0644); 243 244 /* Setup which NMI support is present in system */ 245 static void uv_nmi_setup_mmrs(void) 246 { 247 bool new_nmi_method_only = false; 248 249 /* First determine arch specific MMRs to handshake with BIOS */ 250 if (UVH_EVENT_OCCURRED0_EXTIO_INT0_MASK) { /* UV2,3,4 setup */ 251 uvh_nmi_mmrx = UVH_EVENT_OCCURRED0; 252 uvh_nmi_mmrx_clear = UVH_EVENT_OCCURRED0_ALIAS; 253 uvh_nmi_mmrx_shift = UVH_EVENT_OCCURRED0_EXTIO_INT0_SHFT; 254 uvh_nmi_mmrx_type = "OCRD0-EXTIO_INT0"; 255 256 uvh_nmi_mmrx_supported = UVH_EXTIO_INT0_BROADCAST; 257 uvh_nmi_mmrx_req = UVH_BIOS_KERNEL_MMR_ALIAS_2; 258 uvh_nmi_mmrx_req_shift = 62; 259 260 } else if (UVH_EVENT_OCCURRED1_EXTIO_INT0_MASK) { /* UV5+ setup */ 261 uvh_nmi_mmrx = UVH_EVENT_OCCURRED1; 262 uvh_nmi_mmrx_clear = UVH_EVENT_OCCURRED1_ALIAS; 263 uvh_nmi_mmrx_shift = UVH_EVENT_OCCURRED1_EXTIO_INT0_SHFT; 264 uvh_nmi_mmrx_type = "OCRD1-EXTIO_INT0"; 265 266 new_nmi_method_only = true; /* Newer nmi always valid on UV5+ */ 267 uvh_nmi_mmrx_req = 0; /* no request bit to clear */ 268 269 } else { 270 pr_err("UV:%s:NMI support not available on this system\n", __func__); 271 return; 272 } 273 274 /* Then find out if new NMI is supported */ 275 if (new_nmi_method_only || uv_read_local_mmr(uvh_nmi_mmrx_supported)) { 276 if (uvh_nmi_mmrx_req) 277 uv_write_local_mmr(uvh_nmi_mmrx_req, 278 1UL << uvh_nmi_mmrx_req_shift); 279 nmi_mmr = uvh_nmi_mmrx; 280 nmi_mmr_clear = uvh_nmi_mmrx_clear; 281 nmi_mmr_pending = 1UL << uvh_nmi_mmrx_shift; 282 pr_info("UV: SMI NMI support: %s\n", uvh_nmi_mmrx_type); 283 } else { 284 nmi_mmr = UVH_NMI_MMR; 285 nmi_mmr_clear = UVH_NMI_MMR_CLEAR; 286 nmi_mmr_pending = 1UL << UVH_NMI_MMR_SHIFT; 287 pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMR_TYPE); 288 } 289 } 290 291 /* Read NMI MMR and check if NMI flag was set by BMC. */ 292 static inline int uv_nmi_test_mmr(struct uv_hub_nmi_s *hub_nmi) 293 { 294 hub_nmi->nmi_value = uv_read_local_mmr(nmi_mmr); 295 atomic_inc(&hub_nmi->read_mmr_count); 296 return !!(hub_nmi->nmi_value & nmi_mmr_pending); 297 } 298 299 static inline void uv_local_mmr_clear_nmi(void) 300 { 301 uv_write_local_mmr(nmi_mmr_clear, nmi_mmr_pending); 302 } 303 304 /* 305 * UV hubless NMI handler functions 306 */ 307 static inline void uv_reassert_nmi(void) 308 { 309 /* (from arch/x86/include/asm/mach_traps.h) */ 310 outb(0x8f, NMI_CONTROL_PORT); 311 inb(NMI_DUMMY_PORT); /* dummy read */ 312 outb(0x0f, NMI_CONTROL_PORT); 313 inb(NMI_DUMMY_PORT); /* dummy read */ 314 } 315 316 static void uv_init_hubless_pch_io(int offset, int mask, int data) 317 { 318 int *addr = PCH_PCR_GPIO_ADDRESS(offset); 319 int readd = readl(addr); 320 321 if (mask) { /* OR in new data */ 322 int writed = (readd & ~mask) | data; 323 324 nmi_debug("UV:PCH: %p = %x & %x | %x (%x)\n", 325 addr, readd, ~mask, data, writed); 326 writel(writed, addr); 327 } else if (readd & data) { /* clear status bit */ 328 nmi_debug("UV:PCH: %p = %x\n", addr, data); 329 writel(data, addr); 330 } 331 332 (void)readl(addr); /* flush write data */ 333 } 334 335 static void uv_nmi_setup_hubless_intr(void) 336 { 337 uv_pch_intr_now_enabled = uv_pch_intr_enable; 338 339 uv_init_hubless_pch_io( 340 PAD_CFG_DW0_GPP_D_0, GPIROUTNMI, 341 uv_pch_intr_now_enabled ? GPIROUTNMI : 0); 342 343 nmi_debug("UV:NMI: GPP_D_0 interrupt %s\n", 344 str_enabled_disabled(uv_pch_intr_now_enabled)); 345 } 346 347 static struct init_nmi { 348 unsigned int offset; 349 unsigned int mask; 350 unsigned int data; 351 } init_nmi[] = { 352 { /* HOSTSW_OWN_GPP_D_0 */ 353 .offset = 0x84, 354 .mask = 0x1, 355 .data = 0x0, /* ACPI Mode */ 356 }, 357 358 /* Clear status: */ 359 { /* GPI_INT_STS_GPP_D_0 */ 360 .offset = 0x104, 361 .mask = 0x0, 362 .data = 0x1, /* Clear Status */ 363 }, 364 { /* GPI_GPE_STS_GPP_D_0 */ 365 .offset = 0x124, 366 .mask = 0x0, 367 .data = 0x1, /* Clear Status */ 368 }, 369 { /* GPI_SMI_STS_GPP_D_0 */ 370 .offset = 0x144, 371 .mask = 0x0, 372 .data = 0x1, /* Clear Status */ 373 }, 374 { /* GPI_NMI_STS_GPP_D_0 */ 375 .offset = 0x164, 376 .mask = 0x0, 377 .data = 0x1, /* Clear Status */ 378 }, 379 380 /* Disable interrupts: */ 381 { /* GPI_INT_EN_GPP_D_0 */ 382 .offset = 0x114, 383 .mask = 0x1, 384 .data = 0x0, /* Disable interrupt generation */ 385 }, 386 { /* GPI_GPE_EN_GPP_D_0 */ 387 .offset = 0x134, 388 .mask = 0x1, 389 .data = 0x0, /* Disable interrupt generation */ 390 }, 391 { /* GPI_SMI_EN_GPP_D_0 */ 392 .offset = 0x154, 393 .mask = 0x1, 394 .data = 0x0, /* Disable interrupt generation */ 395 }, 396 { /* GPI_NMI_EN_GPP_D_0 */ 397 .offset = 0x174, 398 .mask = 0x1, 399 .data = 0x0, /* Disable interrupt generation */ 400 }, 401 402 /* Setup GPP_D_0 Pad Config: */ 403 { /* PAD_CFG_DW0_GPP_D_0 */ 404 .offset = 0x4c0, 405 .mask = 0xffffffff, 406 .data = 0x82020100, 407 /* 408 * 31:30 Pad Reset Config (PADRSTCFG): = 2h # PLTRST# (default) 409 * 410 * 29 RX Pad State Select (RXPADSTSEL): = 0 # Raw RX pad state directly 411 * from RX buffer (default) 412 * 413 * 28 RX Raw Override to '1' (RXRAW1): = 0 # No Override 414 * 415 * 26:25 RX Level/Edge Configuration (RXEVCFG): 416 * = 0h # Level 417 * = 1h # Edge 418 * 419 * 23 RX Invert (RXINV): = 0 # No Inversion (signal active high) 420 * 421 * 20 GPIO Input Route IOxAPIC (GPIROUTIOXAPIC): 422 * = 0 # Routing does not cause peripheral IRQ... 423 * # (we want an NMI not an IRQ) 424 * 425 * 19 GPIO Input Route SCI (GPIROUTSCI): = 0 # Routing does not cause SCI. 426 * 18 GPIO Input Route SMI (GPIROUTSMI): = 0 # Routing does not cause SMI. 427 * 17 GPIO Input Route NMI (GPIROUTNMI): = 1 # Routing can cause NMI. 428 * 429 * 11:10 Pad Mode (PMODE1/0): = 0h = GPIO control the Pad. 430 * 9 GPIO RX Disable (GPIORXDIS): 431 * = 0 # Enable the input buffer (active low enable) 432 * 433 * 8 GPIO TX Disable (GPIOTXDIS): 434 * = 1 # Disable the output buffer; i.e. Hi-Z 435 * 436 * 1 GPIO RX State (GPIORXSTATE): This is the current internal RX pad state.. 437 * 0 GPIO TX State (GPIOTXSTATE): 438 * = 0 # (Leave at default) 439 */ 440 }, 441 442 /* Pad Config DW1 */ 443 { /* PAD_CFG_DW1_GPP_D_0 */ 444 .offset = 0x4c4, 445 .mask = 0x3c00, 446 .data = 0, /* Termination = none (default) */ 447 }, 448 }; 449 450 static void uv_init_hubless_pch_d0(void) 451 { 452 int i, read; 453 454 read = *PCH_PCR_GPIO_ADDRESS(PAD_OWN_GPP_D_0); 455 if (read != 0) { 456 pr_info("UV: Hubless NMI already configured\n"); 457 return; 458 } 459 460 nmi_debug("UV: Initializing UV Hubless NMI on PCH\n"); 461 for (i = 0; i < ARRAY_SIZE(init_nmi); i++) { 462 uv_init_hubless_pch_io(init_nmi[i].offset, 463 init_nmi[i].mask, 464 init_nmi[i].data); 465 } 466 } 467 468 static int uv_nmi_test_hubless(struct uv_hub_nmi_s *hub_nmi) 469 { 470 int *pstat = PCH_PCR_GPIO_ADDRESS(GPI_NMI_STS_GPP_D_0); 471 int status = *pstat; 472 473 hub_nmi->nmi_value = status; 474 atomic_inc(&hub_nmi->read_mmr_count); 475 476 if (!(status & STS_GPP_D_0_MASK)) /* Not a UV external NMI */ 477 return 0; 478 479 *pstat = STS_GPP_D_0_MASK; /* Is a UV NMI: clear GPP_D_0 status */ 480 (void)*pstat; /* Flush write */ 481 482 return 1; 483 } 484 485 static int uv_test_nmi(struct uv_hub_nmi_s *hub_nmi) 486 { 487 if (hub_nmi->hub_present) 488 return uv_nmi_test_mmr(hub_nmi); 489 490 if (hub_nmi->pch_owner) /* Only PCH owner can check status */ 491 return uv_nmi_test_hubless(hub_nmi); 492 493 return -1; 494 } 495 496 /* 497 * If first CPU in on this hub, set hub_nmi "in_nmi" and "owner" values and 498 * return true. If first CPU in on the system, set global "in_nmi" flag. 499 */ 500 static int uv_set_in_nmi(int cpu, struct uv_hub_nmi_s *hub_nmi) 501 { 502 int first = atomic_add_unless(&hub_nmi->in_nmi, 1, 1); 503 504 if (first) { 505 atomic_set(&hub_nmi->cpu_owner, cpu); 506 if (atomic_add_unless(&uv_in_nmi, 1, 1)) 507 atomic_set(&uv_nmi_cpu, cpu); 508 509 atomic_inc(&hub_nmi->nmi_count); 510 } 511 return first; 512 } 513 514 /* Check if this is a system NMI event */ 515 static int uv_check_nmi(struct uv_hub_nmi_s *hub_nmi) 516 { 517 int cpu = smp_processor_id(); 518 int nmi = 0; 519 int nmi_detected = 0; 520 521 local64_inc(&uv_nmi_count); 522 this_cpu_inc(uv_cpu_nmi.queries); 523 524 do { 525 nmi = atomic_read(&hub_nmi->in_nmi); 526 if (nmi) 527 break; 528 529 if (raw_spin_trylock(&hub_nmi->nmi_lock)) { 530 nmi_detected = uv_test_nmi(hub_nmi); 531 532 /* Check flag for UV external NMI */ 533 if (nmi_detected > 0) { 534 uv_set_in_nmi(cpu, hub_nmi); 535 nmi = 1; 536 break; 537 } 538 539 /* A non-PCH node in a hubless system waits for NMI */ 540 else if (nmi_detected < 0) 541 goto slave_wait; 542 543 /* MMR/PCH NMI flag is clear */ 544 raw_spin_unlock(&hub_nmi->nmi_lock); 545 546 } else { 547 548 /* Wait a moment for the HUB NMI locker to set flag */ 549 slave_wait: cpu_relax(); 550 udelay(uv_nmi_slave_delay); 551 552 /* Re-check hub in_nmi flag */ 553 nmi = atomic_read(&hub_nmi->in_nmi); 554 if (nmi) 555 break; 556 } 557 558 /* 559 * Check if this BMC missed setting the MMR NMI flag (or) 560 * UV hubless system where only PCH owner can check flag 561 */ 562 if (!nmi) { 563 nmi = atomic_read(&uv_in_nmi); 564 if (nmi) 565 uv_set_in_nmi(cpu, hub_nmi); 566 } 567 568 /* If we're holding the hub lock, release it now */ 569 if (nmi_detected < 0) 570 raw_spin_unlock(&hub_nmi->nmi_lock); 571 572 } while (0); 573 574 if (!nmi) 575 local64_inc(&uv_nmi_misses); 576 577 return nmi; 578 } 579 580 /* Need to reset the NMI MMR register, but only once per hub. */ 581 static inline void uv_clear_nmi(int cpu) 582 { 583 struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi; 584 585 if (cpu == atomic_read(&hub_nmi->cpu_owner)) { 586 atomic_set(&hub_nmi->cpu_owner, -1); 587 atomic_set(&hub_nmi->in_nmi, 0); 588 if (hub_nmi->hub_present) 589 uv_local_mmr_clear_nmi(); 590 else 591 uv_reassert_nmi(); 592 raw_spin_unlock(&hub_nmi->nmi_lock); 593 } 594 } 595 596 /* Ping non-responding CPU's attempting to force them into the NMI handler */ 597 static void uv_nmi_nr_cpus_ping(void) 598 { 599 int cpu; 600 601 for_each_cpu(cpu, uv_nmi_cpu_mask) 602 uv_cpu_nmi_per(cpu).pinging = 1; 603 604 __apic_send_IPI_mask(uv_nmi_cpu_mask, APIC_DM_NMI); 605 } 606 607 /* Clean up flags for CPU's that ignored both NMI and ping */ 608 static void uv_nmi_cleanup_mask(void) 609 { 610 int cpu; 611 612 for_each_cpu(cpu, uv_nmi_cpu_mask) { 613 uv_cpu_nmi_per(cpu).pinging = 0; 614 uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_OUT; 615 cpumask_clear_cpu(cpu, uv_nmi_cpu_mask); 616 } 617 } 618 619 /* Loop waiting as CPU's enter NMI handler */ 620 static int uv_nmi_wait_cpus(int first) 621 { 622 int i, j, k, n = num_online_cpus(); 623 int last_k = 0, waiting = 0; 624 int cpu = smp_processor_id(); 625 626 if (first) { 627 cpumask_copy(uv_nmi_cpu_mask, cpu_online_mask); 628 k = 0; 629 } else { 630 k = n - cpumask_weight(uv_nmi_cpu_mask); 631 } 632 633 /* PCH NMI causes only one CPU to respond */ 634 if (first && uv_pch_intr_now_enabled) { 635 cpumask_clear_cpu(cpu, uv_nmi_cpu_mask); 636 return n - k - 1; 637 } 638 639 udelay(uv_nmi_initial_delay); 640 for (i = 0; i < uv_nmi_retry_count; i++) { 641 int loop_delay = uv_nmi_loop_delay; 642 643 for_each_cpu(j, uv_nmi_cpu_mask) { 644 if (uv_cpu_nmi_per(j).state) { 645 cpumask_clear_cpu(j, uv_nmi_cpu_mask); 646 if (++k >= n) 647 break; 648 } 649 } 650 if (k >= n) { /* all in? */ 651 k = n; 652 break; 653 } 654 if (last_k != k) { /* abort if no new CPU's coming in */ 655 last_k = k; 656 waiting = 0; 657 } else if (++waiting > uv_nmi_wait_count) 658 break; 659 660 /* Extend delay if waiting only for CPU 0: */ 661 if (waiting && (n - k) == 1 && 662 cpumask_test_cpu(0, uv_nmi_cpu_mask)) 663 loop_delay *= 100; 664 665 udelay(loop_delay); 666 } 667 atomic_set(&uv_nmi_cpus_in_nmi, k); 668 return n - k; 669 } 670 671 /* Wait until all slave CPU's have entered UV NMI handler */ 672 static void uv_nmi_wait(int master) 673 { 674 /* Indicate this CPU is in: */ 675 this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_IN); 676 677 /* If not the first CPU in (the master), then we are a slave CPU */ 678 if (!master) 679 return; 680 681 do { 682 /* Wait for all other CPU's to gather here */ 683 if (!uv_nmi_wait_cpus(1)) 684 break; 685 686 /* If not all made it in, send IPI NMI to them */ 687 pr_alert("UV: Sending NMI IPI to %d CPUs: %*pbl\n", 688 cpumask_weight(uv_nmi_cpu_mask), 689 cpumask_pr_args(uv_nmi_cpu_mask)); 690 691 uv_nmi_nr_cpus_ping(); 692 693 /* If all CPU's are in, then done */ 694 if (!uv_nmi_wait_cpus(0)) 695 break; 696 697 pr_alert("UV: %d CPUs not in NMI loop: %*pbl\n", 698 cpumask_weight(uv_nmi_cpu_mask), 699 cpumask_pr_args(uv_nmi_cpu_mask)); 700 } while (0); 701 702 pr_alert("UV: %d of %d CPUs in NMI\n", 703 atomic_read(&uv_nmi_cpus_in_nmi), num_online_cpus()); 704 } 705 706 /* Dump Instruction Pointer header */ 707 static void uv_nmi_dump_cpu_ip_hdr(void) 708 { 709 pr_info("\nUV: %4s %6s %-32s %s (Note: PID 0 not listed)\n", 710 "CPU", "PID", "COMMAND", "IP"); 711 } 712 713 /* Dump Instruction Pointer info */ 714 static void uv_nmi_dump_cpu_ip(int cpu, struct pt_regs *regs) 715 { 716 pr_info("UV: %4d %6d %-32.32s %pS", 717 cpu, current->pid, current->comm, (void *)regs->ip); 718 } 719 720 /* 721 * Dump this CPU's state. If action was set to "kdump" and the crash_kexec 722 * failed, then we provide "dump" as an alternate action. Action "dump" now 723 * also includes the show "ips" (instruction pointers) action whereas the 724 * action "ips" only displays instruction pointers for the non-idle CPU's. 725 * This is an abbreviated form of the "ps" command. 726 */ 727 static void uv_nmi_dump_state_cpu(int cpu, struct pt_regs *regs) 728 { 729 const char *dots = " ................................. "; 730 731 if (cpu == 0) 732 uv_nmi_dump_cpu_ip_hdr(); 733 734 if (current->pid != 0 || uv_nmi_action != nmi_act_ips) 735 uv_nmi_dump_cpu_ip(cpu, regs); 736 737 if (uv_nmi_action == nmi_act_dump) { 738 pr_info("UV:%sNMI process trace for CPU %d\n", dots, cpu); 739 show_regs(regs); 740 } 741 742 this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_DUMP_DONE); 743 } 744 745 /* Trigger a slave CPU to dump its state */ 746 static void uv_nmi_trigger_dump(int cpu) 747 { 748 int retry = uv_nmi_trigger_delay; 749 750 if (uv_cpu_nmi_per(cpu).state != UV_NMI_STATE_IN) 751 return; 752 753 uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_DUMP; 754 do { 755 cpu_relax(); 756 udelay(10); 757 if (uv_cpu_nmi_per(cpu).state 758 != UV_NMI_STATE_DUMP) 759 return; 760 } while (--retry > 0); 761 762 pr_crit("UV: CPU %d stuck in process dump function\n", cpu); 763 uv_cpu_nmi_per(cpu).state = UV_NMI_STATE_DUMP_DONE; 764 } 765 766 /* Wait until all CPU's ready to exit */ 767 static void uv_nmi_sync_exit(int master) 768 { 769 atomic_dec(&uv_nmi_cpus_in_nmi); 770 if (master) { 771 while (atomic_read(&uv_nmi_cpus_in_nmi) > 0) 772 cpu_relax(); 773 atomic_set(&uv_nmi_slave_continue, SLAVE_CLEAR); 774 } else { 775 while (atomic_read(&uv_nmi_slave_continue)) 776 cpu_relax(); 777 } 778 } 779 780 /* Current "health" check is to check which CPU's are responsive */ 781 static void uv_nmi_action_health(int cpu, struct pt_regs *regs, int master) 782 { 783 if (master) { 784 int in = atomic_read(&uv_nmi_cpus_in_nmi); 785 int out = num_online_cpus() - in; 786 787 pr_alert("UV: NMI CPU health check (non-responding:%d)\n", out); 788 atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); 789 } else { 790 while (!atomic_read(&uv_nmi_slave_continue)) 791 cpu_relax(); 792 } 793 uv_nmi_sync_exit(master); 794 } 795 796 /* Walk through CPU list and dump state of each */ 797 static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master) 798 { 799 if (master) { 800 int tcpu; 801 int ignored = 0; 802 int saved_console_loglevel = console_loglevel; 803 804 pr_alert("UV: tracing %s for %d CPUs from CPU %d\n", 805 uv_nmi_action == nmi_act_ips ? "IPs" : "processes", 806 atomic_read(&uv_nmi_cpus_in_nmi), cpu); 807 808 console_loglevel = uv_nmi_loglevel; 809 atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); 810 for_each_online_cpu(tcpu) { 811 if (cpumask_test_cpu(tcpu, uv_nmi_cpu_mask)) 812 ignored++; 813 else if (tcpu == cpu) 814 uv_nmi_dump_state_cpu(tcpu, regs); 815 else 816 uv_nmi_trigger_dump(tcpu); 817 } 818 if (ignored) 819 pr_alert("UV: %d CPUs ignored NMI\n", ignored); 820 821 console_loglevel = saved_console_loglevel; 822 pr_alert("UV: process trace complete\n"); 823 } else { 824 while (!atomic_read(&uv_nmi_slave_continue)) 825 cpu_relax(); 826 while (this_cpu_read(uv_cpu_nmi.state) != UV_NMI_STATE_DUMP) 827 cpu_relax(); 828 uv_nmi_dump_state_cpu(cpu, regs); 829 } 830 uv_nmi_sync_exit(master); 831 } 832 833 static void uv_nmi_touch_watchdogs(void) 834 { 835 touch_softlockup_watchdog_sync(); 836 clocksource_touch_watchdog(); 837 rcu_cpu_stall_reset(); 838 touch_nmi_watchdog(); 839 } 840 841 static void uv_nmi_kdump(int cpu, int main, struct pt_regs *regs) 842 { 843 /* Check if kdump kernel loaded for both main and secondary CPUs */ 844 if (!kexec_crash_image) { 845 if (main) 846 pr_err("UV: NMI error: kdump kernel not loaded\n"); 847 return; 848 } 849 850 /* Call crash to dump system state */ 851 if (main) { 852 pr_emerg("UV: NMI executing crash_kexec on CPU%d\n", cpu); 853 crash_kexec(regs); 854 855 pr_emerg("UV: crash_kexec unexpectedly returned\n"); 856 atomic_set(&uv_nmi_kexec_failed, 1); 857 858 } else { /* secondary */ 859 860 /* If kdump kernel fails, secondaries will exit this loop */ 861 while (atomic_read(&uv_nmi_kexec_failed) == 0) { 862 863 /* Once shootdown cpus starts, they do not return */ 864 run_crash_ipi_callback(regs); 865 866 mdelay(10); 867 } 868 } 869 } 870 871 #ifdef CONFIG_KGDB 872 #ifdef CONFIG_KGDB_KDB 873 static inline int uv_nmi_kdb_reason(void) 874 { 875 return KDB_REASON_SYSTEM_NMI; 876 } 877 #else /* !CONFIG_KGDB_KDB */ 878 static inline int uv_nmi_kdb_reason(void) 879 { 880 /* Ensure user is expecting to attach gdb remote */ 881 if (uv_nmi_action == nmi_act_kgdb) 882 return 0; 883 884 pr_err("UV: NMI error: KDB is not enabled in this kernel\n"); 885 return -1; 886 } 887 #endif /* CONFIG_KGDB_KDB */ 888 889 /* 890 * Call KGDB/KDB from NMI handler 891 * 892 * Note that if both KGDB and KDB are configured, then the action of 'kgdb' or 893 * 'kdb' has no affect on which is used. See the KGDB documentation for further 894 * information. 895 */ 896 static void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master) 897 { 898 if (master) { 899 int reason = uv_nmi_kdb_reason(); 900 int ret; 901 902 if (reason < 0) 903 return; 904 905 /* Call KGDB NMI handler as MASTER */ 906 ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs, reason, 907 &uv_nmi_slave_continue); 908 if (ret) { 909 pr_alert("KGDB returned error, is kgdboc set?\n"); 910 atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); 911 } 912 } else { 913 /* Wait for KGDB signal that it's ready for slaves to enter */ 914 int sig; 915 916 do { 917 cpu_relax(); 918 sig = atomic_read(&uv_nmi_slave_continue); 919 } while (!sig); 920 921 /* Call KGDB as slave */ 922 if (sig == SLAVE_CONTINUE) 923 kgdb_nmicallback(cpu, regs); 924 } 925 uv_nmi_sync_exit(master); 926 } 927 928 #else /* !CONFIG_KGDB */ 929 static inline void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master) 930 { 931 pr_err("UV: NMI error: KGDB is not enabled in this kernel\n"); 932 } 933 #endif /* !CONFIG_KGDB */ 934 935 /* 936 * UV NMI handler 937 */ 938 static int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) 939 { 940 struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi; 941 int cpu = smp_processor_id(); 942 int master = 0; 943 unsigned long flags; 944 945 local_irq_save(flags); 946 947 /* If not a UV System NMI, ignore */ 948 if (!this_cpu_read(uv_cpu_nmi.pinging) && !uv_check_nmi(hub_nmi)) { 949 local_irq_restore(flags); 950 return NMI_DONE; 951 } 952 953 /* Indicate we are the first CPU into the NMI handler */ 954 master = (atomic_read(&uv_nmi_cpu) == cpu); 955 956 /* If NMI action is "kdump", then attempt to do it */ 957 if (uv_nmi_action == nmi_act_kdump) { 958 uv_nmi_kdump(cpu, master, regs); 959 960 /* Unexpected return, revert action to "dump" */ 961 if (master) 962 uv_nmi_action = nmi_act_dump; 963 } 964 965 /* Pause as all CPU's enter the NMI handler */ 966 uv_nmi_wait(master); 967 968 /* Process actions other than "kdump": */ 969 switch (uv_nmi_action) { 970 case nmi_act_health: 971 uv_nmi_action_health(cpu, regs, master); 972 break; 973 case nmi_act_ips: 974 case nmi_act_dump: 975 uv_nmi_dump_state(cpu, regs, master); 976 break; 977 case nmi_act_kdb: 978 case nmi_act_kgdb: 979 uv_call_kgdb_kdb(cpu, regs, master); 980 break; 981 default: 982 if (master) 983 pr_alert("UV: unknown NMI action: %d\n", uv_nmi_action); 984 uv_nmi_sync_exit(master); 985 break; 986 } 987 988 /* Clear per_cpu "in_nmi" flag */ 989 this_cpu_write(uv_cpu_nmi.state, UV_NMI_STATE_OUT); 990 991 /* Clear MMR NMI flag on each hub */ 992 uv_clear_nmi(cpu); 993 994 /* Clear global flags */ 995 if (master) { 996 if (!cpumask_empty(uv_nmi_cpu_mask)) 997 uv_nmi_cleanup_mask(); 998 atomic_set(&uv_nmi_cpus_in_nmi, -1); 999 atomic_set(&uv_nmi_cpu, -1); 1000 atomic_set(&uv_in_nmi, 0); 1001 atomic_set(&uv_nmi_kexec_failed, 0); 1002 atomic_set(&uv_nmi_slave_continue, SLAVE_CLEAR); 1003 } 1004 1005 uv_nmi_touch_watchdogs(); 1006 local_irq_restore(flags); 1007 1008 return NMI_HANDLED; 1009 } 1010 1011 /* 1012 * NMI handler for pulling in CPU's when perf events are grabbing our NMI 1013 */ 1014 static int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs) 1015 { 1016 int ret; 1017 1018 this_cpu_inc(uv_cpu_nmi.queries); 1019 if (!this_cpu_read(uv_cpu_nmi.pinging)) { 1020 local64_inc(&uv_nmi_ping_misses); 1021 return NMI_DONE; 1022 } 1023 1024 this_cpu_inc(uv_cpu_nmi.pings); 1025 local64_inc(&uv_nmi_ping_count); 1026 ret = uv_handle_nmi(reason, regs); 1027 this_cpu_write(uv_cpu_nmi.pinging, 0); 1028 return ret; 1029 } 1030 1031 static void uv_register_nmi_notifier(void) 1032 { 1033 if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv")) 1034 pr_warn("UV: NMI handler failed to register\n"); 1035 1036 if (register_nmi_handler(NMI_LOCAL, uv_handle_nmi_ping, 0, "uvping")) 1037 pr_warn("UV: PING NMI handler failed to register\n"); 1038 } 1039 1040 void uv_nmi_init(void) 1041 { 1042 unsigned int value; 1043 1044 /* 1045 * Unmask NMI on all CPU's 1046 */ 1047 value = apic_read(APIC_LVT1) | APIC_DM_NMI; 1048 value &= ~APIC_LVT_MASKED; 1049 apic_write(APIC_LVT1, value); 1050 } 1051 1052 /* Setup HUB NMI info */ 1053 static void __init uv_nmi_setup_common(bool hubbed) 1054 { 1055 int size = sizeof(void *) * (1 << NODES_SHIFT); 1056 int cpu; 1057 1058 uv_hub_nmi_list = kzalloc(size, GFP_KERNEL); 1059 nmi_debug("UV: NMI hub list @ 0x%p (%d)\n", uv_hub_nmi_list, size); 1060 BUG_ON(!uv_hub_nmi_list); 1061 size = sizeof(struct uv_hub_nmi_s); 1062 for_each_present_cpu(cpu) { 1063 int nid = cpu_to_node(cpu); 1064 if (uv_hub_nmi_list[nid] == NULL) { 1065 uv_hub_nmi_list[nid] = kzalloc_node(size, 1066 GFP_KERNEL, nid); 1067 BUG_ON(!uv_hub_nmi_list[nid]); 1068 raw_spin_lock_init(&(uv_hub_nmi_list[nid]->nmi_lock)); 1069 atomic_set(&uv_hub_nmi_list[nid]->cpu_owner, -1); 1070 uv_hub_nmi_list[nid]->hub_present = hubbed; 1071 uv_hub_nmi_list[nid]->pch_owner = (nid == 0); 1072 } 1073 uv_hub_nmi_per(cpu) = uv_hub_nmi_list[nid]; 1074 } 1075 BUG_ON(!alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL)); 1076 } 1077 1078 /* Setup for UV Hub systems */ 1079 void __init uv_nmi_setup(void) 1080 { 1081 uv_nmi_setup_mmrs(); 1082 uv_nmi_setup_common(true); 1083 uv_register_nmi_notifier(); 1084 pr_info("UV: Hub NMI enabled\n"); 1085 } 1086 1087 /* Setup for UV Hubless systems */ 1088 void __init uv_nmi_setup_hubless(void) 1089 { 1090 uv_nmi_setup_common(false); 1091 pch_base = xlate_dev_mem_ptr(PCH_PCR_GPIO_1_BASE); 1092 nmi_debug("UV: PCH base:%p from 0x%lx, GPP_D_0\n", 1093 pch_base, PCH_PCR_GPIO_1_BASE); 1094 if (uv_pch_init_enable) 1095 uv_init_hubless_pch_d0(); 1096 uv_init_hubless_pch_io(GPI_NMI_ENA_GPP_D_0, 1097 STS_GPP_D_0_MASK, STS_GPP_D_0_MASK); 1098 uv_nmi_setup_hubless_intr(); 1099 /* Ensure NMI enabled in Processor Interface Reg: */ 1100 uv_reassert_nmi(); 1101 uv_register_nmi_notifier(); 1102 pr_info("UV: PCH NMI enabled\n"); 1103 } 1104