arm_sdei.c 24.8 KB
Newer Older
1 2 3 4
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2017 Arm Ltd.
#define pr_fmt(fmt) "sdei: " fmt

5
#include <acpi/ghes.h>
6 7 8
#include <linux/acpi.h>
#include <linux/arm_sdei.h>
#include <linux/arm-smccc.h>
9
#include <linux/atomic.h>
10 11
#include <linux/bitops.h>
#include <linux/compiler.h>
12
#include <linux/cpuhotplug.h>
13
#include <linux/cpu.h>
14
#include <linux/cpu_pm.h>
15 16 17 18 19 20 21
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/kvm_host.h>
#include <linux/list.h>
#include <linux/mutex.h>
22
#include <linux/notifier.h>
23 24 25 26
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/percpu.h>
#include <linux/platform_device.h>
27
#include <linux/pm.h>
28 29
#include <linux/ptrace.h>
#include <linux/preempt.h>
30
#include <linux/reboot.h>
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>

/*
 * The call to use to reach the firmware.
 */
static asmlinkage void (*sdei_firmware_call)(unsigned long function_id,
		      unsigned long arg0, unsigned long arg1,
		      unsigned long arg2, unsigned long arg3,
		      unsigned long arg4, struct arm_smccc_res *res);

/* entry point from firmware to arch asm code */
static unsigned long sdei_entry_point;

struct sdei_event {
48
	/* These three are protected by the sdei_list_lock */
49
	struct list_head	list;
50 51 52
	bool			reregister;
	bool			reenable;

53 54 55 56 57
	u32			event_num;
	u8			type;
	u8			priority;

	/* This pointer is handed to firmware as the event argument. */
58 59 60 61 62 63 64
	union {
		/* Shared events */
		struct sdei_registered_event *registered;

		/* CPU private events */
		struct sdei_registered_event __percpu *private_registered;
	};
65 66 67 68 69 70 71 72 73
};

/* Take the mutex for any API call or modification. Take the mutex first. */
static DEFINE_MUTEX(sdei_events_lock);

/* and then hold this when modifying the list */
static DEFINE_SPINLOCK(sdei_list_lock);
static LIST_HEAD(sdei_list);

74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101
/* Private events are registered/enabled via IPI passing one of these */
struct sdei_crosscall_args {
	struct sdei_event *event;
	atomic_t errors;
	int first_error;
};

#define CROSSCALL_INIT(arg, event)	(arg.event = event, \
					 arg.first_error = 0, \
					 atomic_set(&arg.errors, 0))

static inline int sdei_do_cross_call(void *fn, struct sdei_event * event)
{
	struct sdei_crosscall_args arg;

	CROSSCALL_INIT(arg, event);
	on_each_cpu(fn, &arg, true);

	return arg.first_error;
}

static inline void
sdei_cross_call_return(struct sdei_crosscall_args *arg, int err)
{
	if (err && (atomic_inc_return(&arg->errors) == 1))
		arg->first_error = err;
}

102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167
static int sdei_to_linux_errno(unsigned long sdei_err)
{
	switch (sdei_err) {
	case SDEI_NOT_SUPPORTED:
		return -EOPNOTSUPP;
	case SDEI_INVALID_PARAMETERS:
		return -EINVAL;
	case SDEI_DENIED:
		return -EPERM;
	case SDEI_PENDING:
		return -EINPROGRESS;
	case SDEI_OUT_OF_RESOURCE:
		return -ENOMEM;
	}

	/* Not an error value ... */
	return sdei_err;
}

/*
 * If x0 is any of these values, then the call failed, use sdei_to_linux_errno()
 * to translate.
 */
static int sdei_is_err(struct arm_smccc_res *res)
{
	switch (res->a0) {
	case SDEI_NOT_SUPPORTED:
	case SDEI_INVALID_PARAMETERS:
	case SDEI_DENIED:
	case SDEI_PENDING:
	case SDEI_OUT_OF_RESOURCE:
		return true;
	}

	return false;
}

static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0,
			  unsigned long arg1, unsigned long arg2,
			  unsigned long arg3, unsigned long arg4,
			  u64 *result)
{
	int err = 0;
	struct arm_smccc_res res;

	if (sdei_firmware_call) {
		sdei_firmware_call(function_id, arg0, arg1, arg2, arg3, arg4,
				   &res);
		if (sdei_is_err(&res))
			err = sdei_to_linux_errno(res.a0);
	} else {
		/*
		 * !sdei_firmware_call means we failed to probe or called
		 * sdei_mark_interface_broken(). -EIO is not an error returned
		 * by sdei_to_linux_errno() and is used to suppress messages
		 * from this driver.
		 */
		err = -EIO;
		res.a0 = SDEI_NOT_SUPPORTED;
	}

	if (result)
		*result = res.a0;

	return err;
}
168
NOKPROBE_SYMBOL(invoke_sdei_fn);
169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247

static struct sdei_event *sdei_event_find(u32 event_num)
{
	struct sdei_event *e, *found = NULL;

	lockdep_assert_held(&sdei_events_lock);

	spin_lock(&sdei_list_lock);
	list_for_each_entry(e, &sdei_list, list) {
		if (e->event_num == event_num) {
			found = e;
			break;
		}
	}
	spin_unlock(&sdei_list_lock);

	return found;
}

int sdei_api_event_context(u32 query, u64 *result)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_CONTEXT, query, 0, 0, 0, 0,
			      result);
}
NOKPROBE_SYMBOL(sdei_api_event_context);

static int sdei_api_event_get_info(u32 event, u32 info, u64 *result)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0,
			      0, 0, result);
}

static struct sdei_event *sdei_event_create(u32 event_num,
					    sdei_event_callback *cb,
					    void *cb_arg)
{
	int err;
	u64 result;
	struct sdei_event *event;
	struct sdei_registered_event *reg;

	lockdep_assert_held(&sdei_events_lock);

	event = kzalloc(sizeof(*event), GFP_KERNEL);
	if (!event)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&event->list);
	event->event_num = event_num;

	err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
				      &result);
	if (err) {
		kfree(event);
		return ERR_PTR(err);
	}
	event->priority = result;

	err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_TYPE,
				      &result);
	if (err) {
		kfree(event);
		return ERR_PTR(err);
	}
	event->type = result;

	if (event->type == SDEI_EVENT_TYPE_SHARED) {
		reg = kzalloc(sizeof(*reg), GFP_KERNEL);
		if (!reg) {
			kfree(event);
			return ERR_PTR(-ENOMEM);
		}

		reg->event_num = event_num;
		reg->priority = event->priority;

		reg->callback = cb;
		reg->callback_arg = cb_arg;
		event->registered = reg;
248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267
	} else {
		int cpu;
		struct sdei_registered_event __percpu *regs;

		regs = alloc_percpu(struct sdei_registered_event);
		if (!regs) {
			kfree(event);
			return ERR_PTR(-ENOMEM);
		}

		for_each_possible_cpu(cpu) {
			reg = per_cpu_ptr(regs, cpu);

			reg->event_num = event->event_num;
			reg->priority = event->priority;
			reg->callback = cb;
			reg->callback_arg = cb_arg;
		}

		event->private_registered = regs;
268 269
	}

270 271 272
	spin_lock(&sdei_list_lock);
	list_add(&event->list, &sdei_list);
	spin_unlock(&sdei_list_lock);
273 274 275 276

	return event;
}

277
static void sdei_event_destroy_llocked(struct sdei_event *event)
278 279
{
	lockdep_assert_held(&sdei_events_lock);
280
	lockdep_assert_held(&sdei_list_lock);
281 282 283 284 285

	list_del(&event->list);

	if (event->type == SDEI_EVENT_TYPE_SHARED)
		kfree(event->registered);
286 287
	else
		free_percpu(event->private_registered);
288 289 290 291

	kfree(event);
}

292 293 294 295 296 297 298
static void sdei_event_destroy(struct sdei_event *event)
{
	spin_lock(&sdei_list_lock);
	sdei_event_destroy_llocked(event);
	spin_unlock(&sdei_list_lock);
}

299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389
static int sdei_api_get_version(u64 *version)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version);
}

int sdei_mask_local_cpu(void)
{
	int err;

	WARN_ON_ONCE(preemptible());

	err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_MASK, 0, 0, 0, 0, 0, NULL);
	if (err && err != -EIO) {
		pr_warn_once("failed to mask CPU[%u]: %d\n",
			      smp_processor_id(), err);
		return err;
	}

	return 0;
}

static void _ipi_mask_cpu(void *ignored)
{
	sdei_mask_local_cpu();
}

int sdei_unmask_local_cpu(void)
{
	int err;

	WARN_ON_ONCE(preemptible());

	err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PE_UNMASK, 0, 0, 0, 0, 0, NULL);
	if (err && err != -EIO) {
		pr_warn_once("failed to unmask CPU[%u]: %d\n",
			     smp_processor_id(), err);
		return err;
	}

	return 0;
}

static void _ipi_unmask_cpu(void *ignored)
{
	sdei_unmask_local_cpu();
}

static void _ipi_private_reset(void *ignored)
{
	int err;

	err = invoke_sdei_fn(SDEI_1_0_FN_SDEI_PRIVATE_RESET, 0, 0, 0, 0, 0,
			     NULL);
	if (err && err != -EIO)
		pr_warn_once("failed to reset CPU[%u]: %d\n",
			     smp_processor_id(), err);
}

static int sdei_api_shared_reset(void)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_SHARED_RESET, 0, 0, 0, 0, 0,
			      NULL);
}

static void sdei_mark_interface_broken(void)
{
	pr_err("disabling SDEI firmware interface\n");
	on_each_cpu(&_ipi_mask_cpu, NULL, true);
	sdei_firmware_call = NULL;
}

static int sdei_platform_reset(void)
{
	int err;

	on_each_cpu(&_ipi_private_reset, NULL, true);
	err = sdei_api_shared_reset();
	if (err) {
		pr_err("Failed to reset platform: %d\n", err);
		sdei_mark_interface_broken();
	}

	return err;
}

static int sdei_api_event_enable(u32 event_num)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_ENABLE, event_num, 0, 0, 0,
			      0, NULL);
}

390 391 392 393 394 395 396 397 398 399 400 401 402
/* Called directly by the hotplug callbacks */
static void _local_event_enable(void *data)
{
	int err;
	struct sdei_crosscall_args *arg = data;

	WARN_ON_ONCE(preemptible());

	err = sdei_api_event_enable(arg->event->event_num);

	sdei_cross_call_return(arg, err);
}

403 404 405 406 407 408 409 410 411 412 413 414
int sdei_event_enable(u32 event_num)
{
	int err = -EINVAL;
	struct sdei_event *event;

	mutex_lock(&sdei_events_lock);
	event = sdei_event_find(event_num);
	if (!event) {
		mutex_unlock(&sdei_events_lock);
		return -ENOENT;
	}

415

416
	cpus_read_lock();
417 418
	if (event->type == SDEI_EVENT_TYPE_SHARED)
		err = sdei_api_event_enable(event->event_num);
419 420
	else
		err = sdei_do_cross_call(_local_event_enable, event);
421 422 423 424 425 426 427

	if (!err) {
		spin_lock(&sdei_list_lock);
		event->reenable = true;
		spin_unlock(&sdei_list_lock);
	}
	cpus_read_unlock();
428 429 430 431 432 433 434 435 436 437 438
	mutex_unlock(&sdei_events_lock);

	return err;
}

static int sdei_api_event_disable(u32 event_num)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, event_num, 0, 0,
			      0, 0, NULL);
}

439 440 441 442 443 444 445 446 447 448
static void _ipi_event_disable(void *data)
{
	int err;
	struct sdei_crosscall_args *arg = data;

	err = sdei_api_event_disable(arg->event->event_num);

	sdei_cross_call_return(arg, err);
}

449 450 451 452 453 454 455 456 457 458 459 460
int sdei_event_disable(u32 event_num)
{
	int err = -EINVAL;
	struct sdei_event *event;

	mutex_lock(&sdei_events_lock);
	event = sdei_event_find(event_num);
	if (!event) {
		mutex_unlock(&sdei_events_lock);
		return -ENOENT;
	}

461 462 463 464
	spin_lock(&sdei_list_lock);
	event->reenable = false;
	spin_unlock(&sdei_list_lock);

465 466
	if (event->type == SDEI_EVENT_TYPE_SHARED)
		err = sdei_api_event_disable(event->event_num);
467 468
	else
		err = sdei_do_cross_call(_ipi_event_disable, event);
469 470 471 472 473 474 475 476 477 478 479
	mutex_unlock(&sdei_events_lock);

	return err;
}

static int sdei_api_event_unregister(u32 event_num)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_UNREGISTER, event_num, 0,
			      0, 0, 0, NULL);
}

480 481 482 483 484 485 486 487 488 489 490 491 492
/* Called directly by the hotplug callbacks */
static void _local_event_unregister(void *data)
{
	int err;
	struct sdei_crosscall_args *arg = data;

	WARN_ON_ONCE(preemptible());

	err = sdei_api_event_unregister(arg->event->event_num);

	sdei_cross_call_return(arg, err);
}

493 494 495 496 497 498 499
static int _sdei_event_unregister(struct sdei_event *event)
{
	lockdep_assert_held(&sdei_events_lock);

	if (event->type == SDEI_EVENT_TYPE_SHARED)
		return sdei_api_event_unregister(event->event_num);

500
	return sdei_do_cross_call(_local_event_unregister, event);
501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518
}

int sdei_event_unregister(u32 event_num)
{
	int err;
	struct sdei_event *event;

	WARN_ON(in_nmi());

	mutex_lock(&sdei_events_lock);
	event = sdei_event_find(event_num);
	do {
		if (!event) {
			pr_warn("Event %u not registered\n", event_num);
			err = -ENOENT;
			break;
		}

519 520 521 522 523
		spin_lock(&sdei_list_lock);
		event->reregister = false;
		event->reenable = false;
		spin_unlock(&sdei_list_lock);

524 525 526 527 528 529 530 531 532 533 534
		err = _sdei_event_unregister(event);
		if (err)
			break;

		sdei_event_destroy(event);
	} while (0);
	mutex_unlock(&sdei_events_lock);

	return err;
}

535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559
/*
 * unregister events, but don't destroy them as they are re-registered by
 * sdei_reregister_shared().
 */
static int sdei_unregister_shared(void)
{
	int err = 0;
	struct sdei_event *event;

	mutex_lock(&sdei_events_lock);
	spin_lock(&sdei_list_lock);
	list_for_each_entry(event, &sdei_list, list) {
		if (event->type != SDEI_EVENT_TYPE_SHARED)
			continue;

		err = _sdei_event_unregister(event);
		if (err)
			break;
	}
	spin_unlock(&sdei_list_lock);
	mutex_unlock(&sdei_events_lock);

	return err;
}

560 561 562 563 564 565 566 567
static int sdei_api_event_register(u32 event_num, unsigned long entry_point,
				   void *arg, u64 flags, u64 affinity)
{
	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_REGISTER, event_num,
			      (unsigned long)entry_point, (unsigned long)arg,
			      flags, affinity, NULL);
}

568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
/* Called directly by the hotplug callbacks */
static void _local_event_register(void *data)
{
	int err;
	struct sdei_registered_event *reg;
	struct sdei_crosscall_args *arg = data;

	WARN_ON(preemptible());

	reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id());
	err = sdei_api_event_register(arg->event->event_num, sdei_entry_point,
				      reg, 0, 0);

	sdei_cross_call_return(arg, err);
}

584 585
static int _sdei_event_register(struct sdei_event *event)
{
586 587
	int err;

588 589 590 591 592 593 594 595
	lockdep_assert_held(&sdei_events_lock);

	if (event->type == SDEI_EVENT_TYPE_SHARED)
		return sdei_api_event_register(event->event_num,
					       sdei_entry_point,
					       event->registered,
					       SDEI_EVENT_REGISTER_RM_ANY, 0);

596
	err = sdei_do_cross_call(_local_event_register, event);
597
	if (err)
598 599 600
		sdei_do_cross_call(_local_event_unregister, event);

	return err;
601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625
}

int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
{
	int err;
	struct sdei_event *event;

	WARN_ON(in_nmi());

	mutex_lock(&sdei_events_lock);
	do {
		if (sdei_event_find(event_num)) {
			pr_warn("Event %u already registered\n", event_num);
			err = -EBUSY;
			break;
		}

		event = sdei_event_create(event_num, cb, arg);
		if (IS_ERR(event)) {
			err = PTR_ERR(event);
			pr_warn("Failed to create event %u: %d\n", event_num,
				err);
			break;
		}

626
		cpus_read_lock();
627 628 629 630 631
		err = _sdei_event_register(event);
		if (err) {
			sdei_event_destroy(event);
			pr_warn("Failed to register event %u: %d\n", event_num,
				err);
632 633 634 635
		} else {
			spin_lock(&sdei_list_lock);
			event->reregister = true;
			spin_unlock(&sdei_list_lock);
636
		}
637
		cpus_read_unlock();
638 639 640 641 642 643
	} while (0);
	mutex_unlock(&sdei_events_lock);

	return err;
}

644
static int sdei_reregister_event_llocked(struct sdei_event *event)
645 646 647 648
{
	int err;

	lockdep_assert_held(&sdei_events_lock);
649
	lockdep_assert_held(&sdei_list_lock);
650 651 652 653

	err = _sdei_event_register(event);
	if (err) {
		pr_err("Failed to re-register event %u\n", event->event_num);
654
		sdei_event_destroy_llocked(event);
655 656 657 658 659 660
		return err;
	}

	if (event->reenable) {
		if (event->type == SDEI_EVENT_TYPE_SHARED)
			err = sdei_api_event_enable(event->event_num);
661 662
		else
			err = sdei_do_cross_call(_local_event_enable, event);
663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682
	}

	if (err)
		pr_err("Failed to re-enable event %u\n", event->event_num);

	return err;
}

static int sdei_reregister_shared(void)
{
	int err = 0;
	struct sdei_event *event;

	mutex_lock(&sdei_events_lock);
	spin_lock(&sdei_list_lock);
	list_for_each_entry(event, &sdei_list, list) {
		if (event->type != SDEI_EVENT_TYPE_SHARED)
			continue;

		if (event->reregister) {
683
			err = sdei_reregister_event_llocked(event);
684 685 686 687 688 689 690 691 692 693
			if (err)
				break;
		}
	}
	spin_unlock(&sdei_list_lock);
	mutex_unlock(&sdei_events_lock);

	return err;
}

694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749
static int sdei_cpuhp_down(unsigned int cpu)
{
	struct sdei_event *event;
	struct sdei_crosscall_args arg;

	/* un-register private events */
	spin_lock(&sdei_list_lock);
	list_for_each_entry(event, &sdei_list, list) {
		if (event->type == SDEI_EVENT_TYPE_SHARED)
			continue;

		CROSSCALL_INIT(arg, event);
		/* call the cross-call function locally... */
		_local_event_unregister(&arg);
		if (arg.first_error)
			pr_err("Failed to unregister event %u: %d\n",
			       event->event_num, arg.first_error);
	}
	spin_unlock(&sdei_list_lock);

	return sdei_mask_local_cpu();
}

static int sdei_cpuhp_up(unsigned int cpu)
{
	struct sdei_event *event;
	struct sdei_crosscall_args arg;

	/* re-register/enable private events */
	spin_lock(&sdei_list_lock);
	list_for_each_entry(event, &sdei_list, list) {
		if (event->type == SDEI_EVENT_TYPE_SHARED)
			continue;

		if (event->reregister) {
			CROSSCALL_INIT(arg, event);
			/* call the cross-call function locally... */
			_local_event_register(&arg);
			if (arg.first_error)
				pr_err("Failed to re-register event %u: %d\n",
				       event->event_num, arg.first_error);
		}

		if (event->reenable) {
			CROSSCALL_INIT(arg, event);
			_local_event_enable(&arg);
			if (arg.first_error)
				pr_err("Failed to re-enable event %u: %d\n",
				       event->event_num, arg.first_error);
		}
	}
	spin_unlock(&sdei_list_lock);

	return sdei_unmask_local_cpu();
}

750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
/* When entering idle, mask/unmask events for this cpu */
static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action,
			    void *data)
{
	int rv;

	switch (action) {
	case CPU_PM_ENTER:
		rv = sdei_mask_local_cpu();
		break;
	case CPU_PM_EXIT:
	case CPU_PM_ENTER_FAILED:
		rv = sdei_unmask_local_cpu();
		break;
	default:
		return NOTIFY_DONE;
	}

	if (rv)
		return notifier_from_errno(rv);

	return NOTIFY_OK;
}

static struct notifier_block sdei_pm_nb = {
	.notifier_call = sdei_pm_notifier,
};

static int sdei_device_suspend(struct device *dev)
{
	on_each_cpu(_ipi_mask_cpu, NULL, true);

	return 0;
}

static int sdei_device_resume(struct device *dev)
{
	on_each_cpu(_ipi_unmask_cpu, NULL, true);

	return 0;
}

/*
 * We need all events to be reregistered when we resume from hibernate.
 *
 * The sequence is freeze->thaw. Reboot. freeze->restore. We unregister
 * events during freeze, then re-register and re-enable them during thaw
 * and restore.
 */
static int sdei_device_freeze(struct device *dev)
{
	int err;

803
	/* unregister private events */
804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872
	cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING);

	err = sdei_unregister_shared();
	if (err)
		return err;

	return 0;
}

static int sdei_device_thaw(struct device *dev)
{
	int err;

	/* re-register shared events */
	err = sdei_reregister_shared();
	if (err) {
		pr_warn("Failed to re-register shared events...\n");
		sdei_mark_interface_broken();
		return err;
	}

	err = cpuhp_setup_state(CPUHP_AP_ARM_SDEI_STARTING, "SDEI",
				&sdei_cpuhp_up, &sdei_cpuhp_down);
	if (err)
		pr_warn("Failed to re-register CPU hotplug notifier...\n");

	return err;
}

static int sdei_device_restore(struct device *dev)
{
	int err;

	err = sdei_platform_reset();
	if (err)
		return err;

	return sdei_device_thaw(dev);
}

static const struct dev_pm_ops sdei_pm_ops = {
	.suspend = sdei_device_suspend,
	.resume = sdei_device_resume,
	.freeze = sdei_device_freeze,
	.thaw = sdei_device_thaw,
	.restore = sdei_device_restore,
};

/*
 * Mask all CPUs and unregister all events on panic, reboot or kexec.
 */
static int sdei_reboot_notifier(struct notifier_block *nb, unsigned long action,
				void *data)
{
	/*
	 * We are going to reset the interface, after this there is no point
	 * doing work when we take CPUs offline.
	 */
	cpuhp_remove_state(CPUHP_AP_ARM_SDEI_STARTING);

	sdei_platform_reset();

	return NOTIFY_OK;
}

static struct notifier_block sdei_reboot_nb = {
	.notifier_call = sdei_reboot_notifier,
};

873 874 875 876 877 878 879
static void sdei_smccc_smc(unsigned long function_id,
			   unsigned long arg0, unsigned long arg1,
			   unsigned long arg2, unsigned long arg3,
			   unsigned long arg4, struct arm_smccc_res *res)
{
	arm_smccc_smc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
}
880
NOKPROBE_SYMBOL(sdei_smccc_smc);
881 882 883 884 885 886 887 888

static void sdei_smccc_hvc(unsigned long function_id,
			   unsigned long arg0, unsigned long arg1,
			   unsigned long arg2, unsigned long arg3,
			   unsigned long arg4, struct arm_smccc_res *res)
{
	arm_smccc_hvc(function_id, arg0, arg1, arg2, arg3, arg4, 0, 0, res);
}
889
NOKPROBE_SYMBOL(sdei_smccc_hvc);
890

891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957
int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,
		       sdei_event_callback *critical_cb)
{
	int err;
	u64 result;
	u32 event_num;
	sdei_event_callback *cb;

	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
		return -EOPNOTSUPP;

	event_num = ghes->generic->notify.vector;
	if (event_num == 0) {
		/*
		 * Event 0 is reserved by the specification for
		 * SDEI_EVENT_SIGNAL.
		 */
		return -EINVAL;
	}

	err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
				      &result);
	if (err)
		return err;

	if (result == SDEI_EVENT_PRIORITY_CRITICAL)
		cb = critical_cb;
	else
		cb = normal_cb;

	err = sdei_event_register(event_num, cb, ghes);
	if (!err)
		err = sdei_event_enable(event_num);

	return err;
}

int sdei_unregister_ghes(struct ghes *ghes)
{
	int i;
	int err;
	u32 event_num = ghes->generic->notify.vector;

	might_sleep();

	if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES))
		return -EOPNOTSUPP;

	/*
	 * The event may be running on another CPU. Disable it
	 * to stop new events, then try to unregister a few times.
	 */
	err = sdei_event_disable(event_num);
	if (err)
		return err;

	for (i = 0; i < 3; i++) {
		err = sdei_event_unregister(event_num);
		if (err != -EINPROGRESS)
			break;

		schedule();
	}

	return err;
}

958 959 960 961 962 963 964 965 966
static int sdei_get_conduit(struct platform_device *pdev)
{
	const char *method;
	struct device_node *np = pdev->dev.of_node;

	sdei_firmware_call = NULL;
	if (np) {
		if (of_property_read_string(np, "method", &method)) {
			pr_warn("missing \"method\" property\n");
967
			return SMCCC_CONDUIT_NONE;
968 969 970 971
		}

		if (!strcmp("hvc", method)) {
			sdei_firmware_call = &sdei_smccc_hvc;
972
			return SMCCC_CONDUIT_HVC;
973 974
		} else if (!strcmp("smc", method)) {
			sdei_firmware_call = &sdei_smccc_smc;
975
			return SMCCC_CONDUIT_SMC;
976 977 978
		}

		pr_warn("invalid \"method\" property: %s\n", method);
979 980 981
	} else if (IS_ENABLED(CONFIG_ACPI) && !acpi_disabled) {
		if (acpi_psci_use_hvc()) {
			sdei_firmware_call = &sdei_smccc_hvc;
982
			return SMCCC_CONDUIT_HVC;
983 984
		} else {
			sdei_firmware_call = &sdei_smccc_smc;
985
			return SMCCC_CONDUIT_SMC;
986
		}
987 988
	}

989
	return SMCCC_CONDUIT_NONE;
990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
}

static int sdei_probe(struct platform_device *pdev)
{
	int err;
	u64 ver = 0;
	int conduit;

	conduit = sdei_get_conduit(pdev);
	if (!sdei_firmware_call)
		return 0;

	err = sdei_api_get_version(&ver);
	if (err == -EOPNOTSUPP)
		pr_err("advertised but not implemented in platform firmware\n");
	if (err) {
		pr_err("Failed to get SDEI version: %d\n", err);
		sdei_mark_interface_broken();
		return err;
	}

	pr_info("SDEIv%d.%d (0x%x) detected in firmware.\n",
		(int)SDEI_VERSION_MAJOR(ver), (int)SDEI_VERSION_MINOR(ver),
		(int)SDEI_VERSION_VENDOR(ver));

	if (SDEI_VERSION_MAJOR(ver) != 1) {
		pr_warn("Conflicting SDEI version detected.\n");
		sdei_mark_interface_broken();
		return -EINVAL;
	}

	err = sdei_platform_reset();
	if (err)
		return err;

	sdei_entry_point = sdei_arch_get_entry_point(conduit);
	if (!sdei_entry_point) {
		/* Not supported due to hardware or boot configuration */
		sdei_mark_interface_broken();
		return 0;
	}

1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
	err = cpu_pm_register_notifier(&sdei_pm_nb);
	if (err) {
		pr_warn("Failed to register CPU PM notifier...\n");
		goto error;
	}

	err = register_reboot_notifier(&sdei_reboot_nb);
	if (err) {
		pr_warn("Failed to register reboot notifier...\n");
		goto remove_cpupm;
	}

	err = cpuhp_setup_state(CPUHP_AP_ARM_SDEI_STARTING, "SDEI",
				&sdei_cpuhp_up, &sdei_cpuhp_down);
	if (err) {
		pr_warn("Failed to register CPU hotplug notifier...\n");
		goto remove_reboot;
	}
1050 1051

	return 0;
1052 1053 1054 1055 1056 1057 1058 1059 1060 1061

remove_reboot:
	unregister_reboot_notifier(&sdei_reboot_nb);

remove_cpupm:
	cpu_pm_unregister_notifier(&sdei_pm_nb);

error:
	sdei_mark_interface_broken();
	return err;
1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
}

static const struct of_device_id sdei_of_match[] = {
	{ .compatible = "arm,sdei-1.0" },
	{}
};

static struct platform_driver sdei_driver = {
	.driver		= {
		.name			= "sdei",
1072
		.pm			= &sdei_pm_ops,
1073 1074 1075 1076 1077
		.of_match_table		= sdei_of_match,
	},
	.probe		= sdei_probe,
};

1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
static bool __init sdei_present_acpi(void)
{
	acpi_status status;
	struct acpi_table_header *sdei_table_header;

	if (acpi_disabled)
		return false;

	status = acpi_get_table(ACPI_SIG_SDEI, 0, &sdei_table_header);
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		const char *msg = acpi_format_exception(status);

		pr_info("Failed to get ACPI:SDEI table, %s\n", msg);
	}
	if (ACPI_FAILURE(status))
		return false;

1095 1096
	acpi_put_table(sdei_table_header);

1097 1098 1099
	return true;
}

1100 1101
static int __init sdei_init(void)
{
1102
	int ret = platform_driver_register(&sdei_driver);
1103

1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
	if (!ret && sdei_present_acpi()) {
		struct platform_device *pdev;

		pdev = platform_device_register_simple(sdei_driver.driver.name,
						       0, NULL, 0);
		if (IS_ERR(pdev))
			pr_info("Failed to register ACPI:SDEI platform device %ld\n",
				PTR_ERR(pdev));
	}

	return ret;
1115 1116
}

1117 1118 1119 1120 1121
/*
 * On an ACPI system SDEI needs to be ready before HEST:GHES tries to register
 * its events. ACPI is initialised from a subsys_initcall(), GHES is initialised
 * by device_initcall(). We want to be called in the middle.
 */
1122 1123 1124 1125 1126 1127 1128 1129 1130
subsys_initcall_sync(sdei_init);

int sdei_event_handler(struct pt_regs *regs,
		       struct sdei_registered_event *arg)
{
	int err;
	mm_segment_t orig_addr_limit;
	u32 event_num = arg->event_num;

1131 1132 1133 1134 1135 1136 1137 1138
	/*
	 * Save restore 'fs'.
	 * The architecture's entry code save/restores 'fs' when taking an
	 * exception from the kernel. This ensures addr_limit isn't inherited
	 * if you interrupted something that allowed the uaccess routines to
	 * access kernel memory.
	 * Do the same here because this doesn't come via the same entry code.
	*/
1139
	orig_addr_limit = force_uaccess_begin();
1140 1141 1142 1143 1144 1145

	err = arg->callback(event_num, regs, arg->callback_arg);
	if (err)
		pr_err_ratelimited("event %u on CPU %u failed with error: %d\n",
				   event_num, smp_processor_id(), err);

1146
	force_uaccess_end(orig_addr_limit);
1147 1148 1149 1150

	return err;
}
NOKPROBE_SYMBOL(sdei_event_handler);