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