1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PowerNV OPAL high level interfaces
4  *
5  * Copyright 2011 IBM Corp.
6  */
7 
8 #define pr_fmt(fmt)	"opal: " fmt
9 
10 #include <linux/printk.h>
11 #include <linux/types.h>
12 #include <linux/of.h>
13 #include <linux/of_fdt.h>
14 #include <linux/of_platform.h>
15 #include <linux/of_address.h>
16 #include <linux/interrupt.h>
17 #include <linux/notifier.h>
18 #include <linux/slab.h>
19 #include <linux/sched.h>
20 #include <linux/kobject.h>
21 #include <linux/delay.h>
22 #include <linux/memblock.h>
23 #include <linux/kthread.h>
24 #include <linux/freezer.h>
25 #include <linux/kmsg_dump.h>
26 #include <linux/console.h>
27 #include <linux/sched/debug.h>
28 
29 #include <asm/machdep.h>
30 #include <asm/opal.h>
31 #include <asm/firmware.h>
32 #include <asm/mce.h>
33 #include <asm/imc-pmu.h>
34 #include <asm/bug.h>
35 
36 #include "powernv.h"
37 
38 #define OPAL_MSG_QUEUE_MAX 16
39 
40 struct opal_msg_node {
41 	struct list_head	list;
42 	struct opal_msg		msg;
43 };
44 
45 static DEFINE_SPINLOCK(msg_list_lock);
46 static LIST_HEAD(msg_list);
47 
48 /* /sys/firmware/opal */
49 struct kobject *opal_kobj;
50 
51 struct opal {
52 	u64 base;
53 	u64 entry;
54 	u64 size;
55 } opal;
56 
57 struct mcheck_recoverable_range {
58 	u64 start_addr;
59 	u64 end_addr;
60 	u64 recover_addr;
61 };
62 
63 static int msg_list_size;
64 
65 static struct mcheck_recoverable_range *mc_recoverable_range;
66 static int mc_recoverable_range_len;
67 
68 struct device_node *opal_node;
69 static DEFINE_SPINLOCK(opal_write_lock);
70 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
71 static uint32_t opal_heartbeat;
72 static struct task_struct *kopald_tsk;
73 static struct opal_msg *opal_msg;
74 static u32 opal_msg_size __ro_after_init;
75 
opal_configure_cores(void)76 void __init opal_configure_cores(void)
77 {
78 	u64 reinit_flags = 0;
79 
80 	/* Do the actual re-init, This will clobber all FPRs, VRs, etc...
81 	 *
82 	 * It will preserve non volatile GPRs and HSPRG0/1. It will
83 	 * also restore HIDs and other SPRs to their original value
84 	 * but it might clobber a bunch.
85 	 */
86 #ifdef __BIG_ENDIAN__
87 	reinit_flags |= OPAL_REINIT_CPUS_HILE_BE;
88 #else
89 	reinit_flags |= OPAL_REINIT_CPUS_HILE_LE;
90 #endif
91 
92 	/*
93 	 * POWER9 always support running hash:
94 	 *  ie. Host hash  supports  hash guests
95 	 *      Host radix supports  hash/radix guests
96 	 */
97 	if (early_cpu_has_feature(CPU_FTR_ARCH_300)) {
98 		reinit_flags |= OPAL_REINIT_CPUS_MMU_HASH;
99 		if (early_radix_enabled())
100 			reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX;
101 	}
102 
103 	opal_reinit_cpus(reinit_flags);
104 
105 	/* Restore some bits */
106 	if (cur_cpu_spec->cpu_restore)
107 		cur_cpu_spec->cpu_restore();
108 }
109 
early_init_dt_scan_opal(unsigned long node,const char * uname,int depth,void * data)110 int __init early_init_dt_scan_opal(unsigned long node,
111 				   const char *uname, int depth, void *data)
112 {
113 	const void *basep, *entryp, *sizep;
114 	int basesz, entrysz, runtimesz;
115 
116 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
117 		return 0;
118 
119 	basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
120 	entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
121 	sizep = of_get_flat_dt_prop(node, "opal-runtime-size", &runtimesz);
122 
123 	if (!basep || !entryp || !sizep)
124 		return 1;
125 
126 	opal.base = of_read_number(basep, basesz/4);
127 	opal.entry = of_read_number(entryp, entrysz/4);
128 	opal.size = of_read_number(sizep, runtimesz/4);
129 
130 	pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
131 		 opal.base, basep, basesz);
132 	pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
133 		 opal.entry, entryp, entrysz);
134 	pr_debug("OPAL Entry = 0x%llx (sizep=%p runtimesz=%d)\n",
135 		 opal.size, sizep, runtimesz);
136 
137 	if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
138 		powerpc_firmware_features |= FW_FEATURE_OPAL;
139 		pr_debug("OPAL detected !\n");
140 	} else {
141 		panic("OPAL != V3 detected, no longer supported.\n");
142 	}
143 
144 	return 1;
145 }
146 
early_init_dt_scan_recoverable_ranges(unsigned long node,const char * uname,int depth,void * data)147 int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
148 				   const char *uname, int depth, void *data)
149 {
150 	int i, psize, size;
151 	const __be32 *prop;
152 
153 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
154 		return 0;
155 
156 	prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);
157 
158 	if (!prop)
159 		return 1;
160 
161 	pr_debug("Found machine check recoverable ranges.\n");
162 
163 	/*
164 	 * Calculate number of available entries.
165 	 *
166 	 * Each recoverable address range entry is (start address, len,
167 	 * recovery address), 2 cells each for start and recovery address,
168 	 * 1 cell for len, totalling 5 cells per entry.
169 	 */
170 	mc_recoverable_range_len = psize / (sizeof(*prop) * 5);
171 
172 	/* Sanity check */
173 	if (!mc_recoverable_range_len)
174 		return 1;
175 
176 	/* Size required to hold all the entries. */
177 	size = mc_recoverable_range_len *
178 			sizeof(struct mcheck_recoverable_range);
179 
180 	/*
181 	 * Allocate a buffer to hold the MC recoverable ranges.
182 	 */
183 	mc_recoverable_range = memblock_alloc(size, __alignof__(u64));
184 	if (!mc_recoverable_range)
185 		panic("%s: Failed to allocate %u bytes align=0x%lx\n",
186 		      __func__, size, __alignof__(u64));
187 
188 	for (i = 0; i < mc_recoverable_range_len; i++) {
189 		mc_recoverable_range[i].start_addr =
190 					of_read_number(prop + (i * 5) + 0, 2);
191 		mc_recoverable_range[i].end_addr =
192 					mc_recoverable_range[i].start_addr +
193 					of_read_number(prop + (i * 5) + 2, 1);
194 		mc_recoverable_range[i].recover_addr =
195 					of_read_number(prop + (i * 5) + 3, 2);
196 
197 		pr_debug("Machine check recoverable range: %llx..%llx: %llx\n",
198 				mc_recoverable_range[i].start_addr,
199 				mc_recoverable_range[i].end_addr,
200 				mc_recoverable_range[i].recover_addr);
201 	}
202 	return 1;
203 }
204 
opal_register_exception_handlers(void)205 static int __init opal_register_exception_handlers(void)
206 {
207 #ifdef __BIG_ENDIAN__
208 	u64 glue;
209 
210 	if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
211 		return -ENODEV;
212 
213 	/* Hookup some exception handlers except machine check. We use the
214 	 * fwnmi area at 0x7000 to provide the glue space to OPAL
215 	 */
216 	glue = 0x7000;
217 
218 	/*
219 	 * Only ancient OPAL firmware requires this.
220 	 * Specifically, firmware from FW810.00 (released June 2014)
221 	 * through FW810.20 (Released October 2014).
222 	 *
223 	 * Check if we are running on newer (post Oct 2014) firmware that
224 	 * exports the OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to
225 	 * patch the HMI interrupt and we catch it directly in Linux.
226 	 *
227 	 * For older firmware (i.e < FW810.20), we fallback to old behavior and
228 	 * let OPAL patch the HMI vector and handle it inside OPAL firmware.
229 	 *
230 	 * For newer firmware we catch/handle the HMI directly in Linux.
231 	 */
232 	if (!opal_check_token(OPAL_HANDLE_HMI)) {
233 		pr_info("Old firmware detected, OPAL handles HMIs.\n");
234 		opal_register_exception_handler(
235 				OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
236 				0, glue);
237 		glue += 128;
238 	}
239 
240 	/*
241 	 * Only applicable to ancient firmware, all modern
242 	 * (post March 2015/skiboot 5.0) firmware will just return
243 	 * OPAL_UNSUPPORTED.
244 	 */
245 	opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
246 #endif
247 
248 	return 0;
249 }
250 machine_early_initcall(powernv, opal_register_exception_handlers);
251 
queue_replay_msg(void * msg)252 static void queue_replay_msg(void *msg)
253 {
254 	struct opal_msg_node *msg_node;
255 
256 	if (msg_list_size < OPAL_MSG_QUEUE_MAX) {
257 		msg_node = kzalloc(sizeof(*msg_node), GFP_ATOMIC);
258 		if (msg_node) {
259 			INIT_LIST_HEAD(&msg_node->list);
260 			memcpy(&msg_node->msg, msg, sizeof(struct opal_msg));
261 			list_add_tail(&msg_node->list, &msg_list);
262 			msg_list_size++;
263 		} else
264 			pr_warn_once("message queue no memory\n");
265 
266 		if (msg_list_size >= OPAL_MSG_QUEUE_MAX)
267 			pr_warn_once("message queue full\n");
268 	}
269 }
270 
dequeue_replay_msg(enum opal_msg_type msg_type)271 static void dequeue_replay_msg(enum opal_msg_type msg_type)
272 {
273 	struct opal_msg_node *msg_node, *tmp;
274 
275 	list_for_each_entry_safe(msg_node, tmp, &msg_list, list) {
276 		if (be32_to_cpu(msg_node->msg.msg_type) != msg_type)
277 			continue;
278 
279 		atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
280 					msg_type,
281 					&msg_node->msg);
282 
283 		list_del(&msg_node->list);
284 		kfree(msg_node);
285 		msg_list_size--;
286 	}
287 }
288 
289 /*
290  * Opal message notifier based on message type. Allow subscribers to get
291  * notified for specific messgae type.
292  */
opal_message_notifier_register(enum opal_msg_type msg_type,struct notifier_block * nb)293 int opal_message_notifier_register(enum opal_msg_type msg_type,
294 					struct notifier_block *nb)
295 {
296 	int ret;
297 	unsigned long flags;
298 
299 	if (!nb || msg_type >= OPAL_MSG_TYPE_MAX) {
300 		pr_warn("%s: Invalid arguments, msg_type:%d\n",
301 			__func__, msg_type);
302 		return -EINVAL;
303 	}
304 
305 	spin_lock_irqsave(&msg_list_lock, flags);
306 	ret = atomic_notifier_chain_register(
307 		&opal_msg_notifier_head[msg_type], nb);
308 
309 	/*
310 	 * If the registration succeeded, replay any queued messages that came
311 	 * in prior to the notifier chain registration. msg_list_lock held here
312 	 * to ensure they're delivered prior to any subsequent messages.
313 	 */
314 	if (ret == 0)
315 		dequeue_replay_msg(msg_type);
316 
317 	spin_unlock_irqrestore(&msg_list_lock, flags);
318 
319 	return ret;
320 }
321 EXPORT_SYMBOL_GPL(opal_message_notifier_register);
322 
opal_message_notifier_unregister(enum opal_msg_type msg_type,struct notifier_block * nb)323 int opal_message_notifier_unregister(enum opal_msg_type msg_type,
324 				     struct notifier_block *nb)
325 {
326 	return atomic_notifier_chain_unregister(
327 			&opal_msg_notifier_head[msg_type], nb);
328 }
329 EXPORT_SYMBOL_GPL(opal_message_notifier_unregister);
330 
opal_message_do_notify(uint32_t msg_type,void * msg)331 static void opal_message_do_notify(uint32_t msg_type, void *msg)
332 {
333 	unsigned long flags;
334 	bool queued = false;
335 
336 	spin_lock_irqsave(&msg_list_lock, flags);
337 	if (opal_msg_notifier_head[msg_type].head == NULL) {
338 		/*
339 		 * Queue up the msg since no notifiers have registered
340 		 * yet for this msg_type.
341 		 */
342 		queue_replay_msg(msg);
343 		queued = true;
344 	}
345 	spin_unlock_irqrestore(&msg_list_lock, flags);
346 
347 	if (queued)
348 		return;
349 
350 	/* notify subscribers */
351 	atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
352 					msg_type, msg);
353 }
354 
opal_handle_message(void)355 static void opal_handle_message(void)
356 {
357 	s64 ret;
358 	u32 type;
359 
360 	ret = opal_get_msg(__pa(opal_msg), opal_msg_size);
361 	/* No opal message pending. */
362 	if (ret == OPAL_RESOURCE)
363 		return;
364 
365 	/* check for errors. */
366 	if (ret) {
367 		pr_warn("%s: Failed to retrieve opal message, err=%lld\n",
368 			__func__, ret);
369 		return;
370 	}
371 
372 	type = be32_to_cpu(opal_msg->msg_type);
373 
374 	/* Sanity check */
375 	if (type >= OPAL_MSG_TYPE_MAX) {
376 		pr_warn_once("%s: Unknown message type: %u\n", __func__, type);
377 		return;
378 	}
379 	opal_message_do_notify(type, (void *)opal_msg);
380 }
381 
opal_message_notify(int irq,void * data)382 static irqreturn_t opal_message_notify(int irq, void *data)
383 {
384 	opal_handle_message();
385 	return IRQ_HANDLED;
386 }
387 
opal_message_init(struct device_node * opal_node)388 static int __init opal_message_init(struct device_node *opal_node)
389 {
390 	int ret, i, irq;
391 
392 	ret = of_property_read_u32(opal_node, "opal-msg-size", &opal_msg_size);
393 	if (ret) {
394 		pr_notice("Failed to read opal-msg-size property\n");
395 		opal_msg_size = sizeof(struct opal_msg);
396 	}
397 
398 	opal_msg = kmalloc(opal_msg_size, GFP_KERNEL);
399 	if (!opal_msg) {
400 		opal_msg_size = sizeof(struct opal_msg);
401 		/* Try to allocate fixed message size */
402 		opal_msg = kmalloc(opal_msg_size, GFP_KERNEL);
403 		BUG_ON(opal_msg == NULL);
404 	}
405 
406 	for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
407 		ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
408 
409 	irq = opal_event_request(ilog2(OPAL_EVENT_MSG_PENDING));
410 	if (!irq) {
411 		pr_err("%s: Can't register OPAL event irq (%d)\n",
412 		       __func__, irq);
413 		return irq;
414 	}
415 
416 	ret = request_irq(irq, opal_message_notify,
417 			IRQ_TYPE_LEVEL_HIGH, "opal-msg", NULL);
418 	if (ret) {
419 		pr_err("%s: Can't request OPAL event irq (%d)\n",
420 		       __func__, ret);
421 		return ret;
422 	}
423 
424 	return 0;
425 }
426 
opal_get_chars(uint32_t vtermno,u8 * buf,size_t count)427 ssize_t opal_get_chars(uint32_t vtermno, u8 *buf, size_t count)
428 {
429 	s64 rc;
430 	__be64 evt, len;
431 
432 	if (!opal.entry)
433 		return -ENODEV;
434 	opal_poll_events(&evt);
435 	if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
436 		return 0;
437 	len = cpu_to_be64(count);
438 	rc = opal_console_read(vtermno, &len, buf);
439 	if (rc == OPAL_SUCCESS)
440 		return be64_to_cpu(len);
441 	return 0;
442 }
443 
__opal_put_chars(uint32_t vtermno,const u8 * data,size_t total_len,bool atomic)444 static ssize_t __opal_put_chars(uint32_t vtermno, const u8 *data,
445 				size_t total_len, bool atomic)
446 {
447 	unsigned long flags = 0 /* shut up gcc */;
448 	ssize_t written;
449 	__be64 olen;
450 	s64 rc;
451 
452 	if (!opal.entry)
453 		return -ENODEV;
454 
455 	if (atomic)
456 		spin_lock_irqsave(&opal_write_lock, flags);
457 	rc = opal_console_write_buffer_space(vtermno, &olen);
458 	if (rc || be64_to_cpu(olen) < total_len) {
459 		/* Closed -> drop characters */
460 		if (rc)
461 			written = total_len;
462 		else
463 			written = -EAGAIN;
464 		goto out;
465 	}
466 
467 	/* Should not get a partial write here because space is available. */
468 	olen = cpu_to_be64(total_len);
469 	rc = opal_console_write(vtermno, &olen, data);
470 	if (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
471 		if (rc == OPAL_BUSY_EVENT)
472 			opal_poll_events(NULL);
473 		written = -EAGAIN;
474 		goto out;
475 	}
476 
477 	/* Closed or other error drop */
478 	if (rc != OPAL_SUCCESS) {
479 		written = opal_error_code(rc);
480 		goto out;
481 	}
482 
483 	written = be64_to_cpu(olen);
484 	if (written < total_len) {
485 		if (atomic) {
486 			/* Should not happen */
487 			pr_warn("atomic console write returned partial "
488 				"len=%zu written=%zd\n", total_len, written);
489 		}
490 		if (!written)
491 			written = -EAGAIN;
492 	}
493 
494 out:
495 	if (atomic)
496 		spin_unlock_irqrestore(&opal_write_lock, flags);
497 
498 	return written;
499 }
500 
opal_put_chars(uint32_t vtermno,const u8 * data,size_t total_len)501 ssize_t opal_put_chars(uint32_t vtermno, const u8 *data, size_t total_len)
502 {
503 	return __opal_put_chars(vtermno, data, total_len, false);
504 }
505 
506 /*
507  * opal_put_chars_atomic will not perform partial-writes. Data will be
508  * atomically written to the terminal or not at all. This is not strictly
509  * true at the moment because console space can race with OPAL's console
510  * writes.
511  */
opal_put_chars_atomic(uint32_t vtermno,const u8 * data,size_t total_len)512 ssize_t opal_put_chars_atomic(uint32_t vtermno, const u8 *data,
513 			      size_t total_len)
514 {
515 	return __opal_put_chars(vtermno, data, total_len, true);
516 }
517 
__opal_flush_console(uint32_t vtermno)518 static s64 __opal_flush_console(uint32_t vtermno)
519 {
520 	s64 rc;
521 
522 	if (!opal_check_token(OPAL_CONSOLE_FLUSH)) {
523 		__be64 evt;
524 
525 		/*
526 		 * If OPAL_CONSOLE_FLUSH is not implemented in the firmware,
527 		 * the console can still be flushed by calling the polling
528 		 * function while it has OPAL_EVENT_CONSOLE_OUTPUT events.
529 		 */
530 		WARN_ONCE(1, "opal: OPAL_CONSOLE_FLUSH missing.\n");
531 
532 		opal_poll_events(&evt);
533 		if (!(be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT))
534 			return OPAL_SUCCESS;
535 		return OPAL_BUSY;
536 
537 	} else {
538 		rc = opal_console_flush(vtermno);
539 		if (rc == OPAL_BUSY_EVENT) {
540 			opal_poll_events(NULL);
541 			rc = OPAL_BUSY;
542 		}
543 		return rc;
544 	}
545 
546 }
547 
548 /*
549  * opal_flush_console spins until the console is flushed
550  */
opal_flush_console(uint32_t vtermno)551 int opal_flush_console(uint32_t vtermno)
552 {
553 	for (;;) {
554 		s64 rc = __opal_flush_console(vtermno);
555 
556 		if (rc == OPAL_BUSY || rc == OPAL_PARTIAL) {
557 			mdelay(1);
558 			continue;
559 		}
560 
561 		return opal_error_code(rc);
562 	}
563 }
564 
565 /*
566  * opal_flush_chars is an hvc interface that sleeps until the console is
567  * flushed if wait, otherwise it will return -EBUSY if the console has data,
568  * -EAGAIN if it has data and some of it was flushed.
569  */
opal_flush_chars(uint32_t vtermno,bool wait)570 int opal_flush_chars(uint32_t vtermno, bool wait)
571 {
572 	for (;;) {
573 		s64 rc = __opal_flush_console(vtermno);
574 
575 		if (rc == OPAL_BUSY || rc == OPAL_PARTIAL) {
576 			if (wait) {
577 				msleep(OPAL_BUSY_DELAY_MS);
578 				continue;
579 			}
580 			if (rc == OPAL_PARTIAL)
581 				return -EAGAIN;
582 		}
583 
584 		return opal_error_code(rc);
585 	}
586 }
587 
opal_recover_mce(struct pt_regs * regs,struct machine_check_event * evt)588 static int opal_recover_mce(struct pt_regs *regs,
589 					struct machine_check_event *evt)
590 {
591 	int recovered = 0;
592 
593 	if (regs_is_unrecoverable(regs)) {
594 		/* If MSR_RI isn't set, we cannot recover */
595 		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
596 		recovered = 0;
597 	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
598 		/* Platform corrected itself */
599 		recovered = 1;
600 	} else if (evt->severity == MCE_SEV_FATAL) {
601 		/* Fatal machine check */
602 		pr_err("Machine check interrupt is fatal\n");
603 		recovered = 0;
604 	}
605 
606 	if (!recovered && evt->sync_error) {
607 		/*
608 		 * Try to kill processes if we get a synchronous machine check
609 		 * (e.g., one caused by execution of this instruction). This
610 		 * will devolve into a panic if we try to kill init or are in
611 		 * an interrupt etc.
612 		 *
613 		 * TODO: Queue up this address for hwpoisioning later.
614 		 * TODO: This is not quite right for d-side machine
615 		 *       checks ->nip is not necessarily the important
616 		 *       address.
617 		 */
618 		if ((user_mode(regs))) {
619 			_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
620 			recovered = 1;
621 		} else if (die_will_crash()) {
622 			/*
623 			 * die() would kill the kernel, so better to go via
624 			 * the platform reboot code that will log the
625 			 * machine check.
626 			 */
627 			recovered = 0;
628 		} else {
629 			die_mce("Machine check", regs, SIGBUS);
630 			recovered = 1;
631 		}
632 	}
633 
634 	return recovered;
635 }
636 
pnv_platform_error_reboot(struct pt_regs * regs,const char * msg)637 void __noreturn pnv_platform_error_reboot(struct pt_regs *regs, const char *msg)
638 {
639 	panic_flush_kmsg_start();
640 
641 	pr_emerg("Hardware platform error: %s\n", msg);
642 	if (regs)
643 		show_regs(regs);
644 	smp_send_stop();
645 
646 	panic_flush_kmsg_end();
647 
648 	/*
649 	 * Don't bother to shut things down because this will
650 	 * xstop the system.
651 	 */
652 	if (opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR, msg)
653 						== OPAL_UNSUPPORTED) {
654 		pr_emerg("Reboot type %d not supported for %s\n",
655 				OPAL_REBOOT_PLATFORM_ERROR, msg);
656 	}
657 
658 	/*
659 	 * We reached here. There can be three possibilities:
660 	 * 1. We are running on a firmware level that do not support
661 	 *    opal_cec_reboot2()
662 	 * 2. We are running on a firmware level that do not support
663 	 *    OPAL_REBOOT_PLATFORM_ERROR reboot type.
664 	 * 3. We are running on FSP based system that does not need
665 	 *    opal to trigger checkstop explicitly for error analysis.
666 	 *    The FSP PRD component would have already got notified
667 	 *    about this error through other channels.
668 	 * 4. We are running on a newer skiboot that by default does
669 	 *    not cause a checkstop, drops us back to the kernel to
670 	 *    extract context and state at the time of the error.
671 	 */
672 
673 	panic(msg);
674 }
675 
opal_machine_check(struct pt_regs * regs)676 int opal_machine_check(struct pt_regs *regs)
677 {
678 	struct machine_check_event evt;
679 
680 	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
681 		return 0;
682 
683 	/* Print things out */
684 	if (evt.version != MCE_V1) {
685 		pr_err("Machine Check Exception, Unknown event version %d !\n",
686 		       evt.version);
687 		return 0;
688 	}
689 	machine_check_print_event_info(&evt, user_mode(regs), false);
690 
691 	if (opal_recover_mce(regs, &evt))
692 		return 1;
693 
694 	pnv_platform_error_reboot(regs, "Unrecoverable Machine Check exception");
695 }
696 
697 /* Early hmi handler called in real mode. */
opal_hmi_exception_early(struct pt_regs * regs)698 int opal_hmi_exception_early(struct pt_regs *regs)
699 {
700 	s64 rc;
701 
702 	/*
703 	 * call opal hmi handler. Pass paca address as token.
704 	 * The return value OPAL_SUCCESS is an indication that there is
705 	 * an HMI event generated waiting to pull by Linux.
706 	 */
707 	rc = opal_handle_hmi();
708 	if (rc == OPAL_SUCCESS) {
709 		local_paca->hmi_event_available = 1;
710 		return 1;
711 	}
712 	return 0;
713 }
714 
opal_hmi_exception_early2(struct pt_regs * regs)715 int opal_hmi_exception_early2(struct pt_regs *regs)
716 {
717 	s64 rc;
718 	__be64 out_flags;
719 
720 	/*
721 	 * call opal hmi handler.
722 	 * Check 64-bit flag mask to find out if an event was generated,
723 	 * and whether TB is still valid or not etc.
724 	 */
725 	rc = opal_handle_hmi2(&out_flags);
726 	if (rc != OPAL_SUCCESS)
727 		return 0;
728 
729 	if (be64_to_cpu(out_flags) & OPAL_HMI_FLAGS_NEW_EVENT)
730 		local_paca->hmi_event_available = 1;
731 	if (be64_to_cpu(out_flags) & OPAL_HMI_FLAGS_TOD_TB_FAIL)
732 		tb_invalid = true;
733 	return 1;
734 }
735 
736 /* HMI exception handler called in virtual mode when irqs are next enabled. */
opal_handle_hmi_exception(struct pt_regs * regs)737 int opal_handle_hmi_exception(struct pt_regs *regs)
738 {
739 	/*
740 	 * Check if HMI event is available.
741 	 * if Yes, then wake kopald to process them.
742 	 */
743 	if (!local_paca->hmi_event_available)
744 		return 0;
745 
746 	local_paca->hmi_event_available = 0;
747 	opal_wake_poller();
748 
749 	return 1;
750 }
751 
find_recovery_address(uint64_t nip)752 static uint64_t find_recovery_address(uint64_t nip)
753 {
754 	int i;
755 
756 	for (i = 0; i < mc_recoverable_range_len; i++)
757 		if ((nip >= mc_recoverable_range[i].start_addr) &&
758 		    (nip < mc_recoverable_range[i].end_addr))
759 		    return mc_recoverable_range[i].recover_addr;
760 	return 0;
761 }
762 
opal_mce_check_early_recovery(struct pt_regs * regs)763 bool opal_mce_check_early_recovery(struct pt_regs *regs)
764 {
765 	uint64_t recover_addr = 0;
766 
767 	if (!opal.base || !opal.size)
768 		goto out;
769 
770 	if ((regs->nip >= opal.base) &&
771 			(regs->nip < (opal.base + opal.size)))
772 		recover_addr = find_recovery_address(regs->nip);
773 
774 	/*
775 	 * Setup regs->nip to rfi into fixup address.
776 	 */
777 	if (recover_addr)
778 		regs_set_return_ip(regs, recover_addr);
779 
780 out:
781 	return !!recover_addr;
782 }
783 
opal_sysfs_init(void)784 static int __init opal_sysfs_init(void)
785 {
786 	opal_kobj = kobject_create_and_add("opal", firmware_kobj);
787 	if (!opal_kobj) {
788 		pr_warn("kobject_create_and_add opal failed\n");
789 		return -ENOMEM;
790 	}
791 
792 	return 0;
793 }
794 
opal_add_one_export(struct kobject * parent,const char * export_name,struct device_node * np,const char * prop_name)795 static int opal_add_one_export(struct kobject *parent, const char *export_name,
796 			       struct device_node *np, const char *prop_name)
797 {
798 	struct bin_attribute *attr = NULL;
799 	const char *name = NULL;
800 	u64 vals[2];
801 	int rc;
802 
803 	rc = of_property_read_u64_array(np, prop_name, &vals[0], 2);
804 	if (rc)
805 		goto out;
806 
807 	attr = kzalloc(sizeof(*attr), GFP_KERNEL);
808 	if (!attr) {
809 		rc = -ENOMEM;
810 		goto out;
811 	}
812 	name = kstrdup(export_name, GFP_KERNEL);
813 	if (!name) {
814 		rc = -ENOMEM;
815 		goto out;
816 	}
817 
818 	sysfs_bin_attr_init(attr);
819 	attr->attr.name = name;
820 	attr->attr.mode = 0400;
821 	attr->read = sysfs_bin_attr_simple_read;
822 	attr->private = __va(vals[0]);
823 	attr->size = vals[1];
824 
825 	rc = sysfs_create_bin_file(parent, attr);
826 out:
827 	if (rc) {
828 		kfree(name);
829 		kfree(attr);
830 	}
831 
832 	return rc;
833 }
834 
opal_add_exported_attrs(struct device_node * np,struct kobject * kobj)835 static void opal_add_exported_attrs(struct device_node *np,
836 				    struct kobject *kobj)
837 {
838 	struct device_node *child;
839 	struct property *prop;
840 
841 	for_each_property_of_node(np, prop) {
842 		int rc;
843 
844 		if (!strcmp(prop->name, "name") ||
845 		    !strcmp(prop->name, "phandle"))
846 			continue;
847 
848 		rc = opal_add_one_export(kobj, prop->name, np, prop->name);
849 		if (rc) {
850 			pr_warn("Unable to add export %pOF/%s, rc = %d!\n",
851 				np, prop->name, rc);
852 		}
853 	}
854 
855 	for_each_child_of_node(np, child) {
856 		struct kobject *child_kobj;
857 
858 		child_kobj = kobject_create_and_add(child->name, kobj);
859 		if (!child_kobj) {
860 			pr_err("Unable to create export dir for %pOF\n", child);
861 			continue;
862 		}
863 
864 		opal_add_exported_attrs(child, child_kobj);
865 	}
866 }
867 
868 /*
869  * opal_export_attrs: creates a sysfs node for each property listed in
870  * the device-tree under /ibm,opal/firmware/exports/
871  * All new sysfs nodes are created under /opal/exports/.
872  * This allows for reserved memory regions (e.g. HDAT) to be read.
873  * The new sysfs nodes are only readable by root.
874  */
opal_export_attrs(void)875 static void opal_export_attrs(void)
876 {
877 	struct device_node *np;
878 	struct kobject *kobj;
879 	int rc;
880 
881 	np = of_find_node_by_path("/ibm,opal/firmware/exports");
882 	if (!np)
883 		return;
884 
885 	/* Create new 'exports' directory - /sys/firmware/opal/exports */
886 	kobj = kobject_create_and_add("exports", opal_kobj);
887 	if (!kobj) {
888 		pr_warn("kobject_create_and_add() of exports failed\n");
889 		of_node_put(np);
890 		return;
891 	}
892 
893 	opal_add_exported_attrs(np, kobj);
894 
895 	/*
896 	 * NB: symbol_map existed before the generic export interface so it
897 	 * lives under the top level opal_kobj.
898 	 */
899 	rc = opal_add_one_export(opal_kobj, "symbol_map",
900 				 np->parent, "symbol-map");
901 	if (rc)
902 		pr_warn("Error %d creating OPAL symbols file\n", rc);
903 
904 	of_node_put(np);
905 }
906 
opal_dump_region_init(void)907 static void __init opal_dump_region_init(void)
908 {
909 	void *addr;
910 	uint64_t size;
911 	int rc;
912 
913 	if (!opal_check_token(OPAL_REGISTER_DUMP_REGION))
914 		return;
915 
916 	/* Register kernel log buffer */
917 	addr = log_buf_addr_get();
918 	if (addr == NULL)
919 		return;
920 
921 	size = log_buf_len_get();
922 	if (size == 0)
923 		return;
924 
925 	rc = opal_register_dump_region(OPAL_DUMP_REGION_LOG_BUF,
926 				       __pa(addr), size);
927 	/* Don't warn if this is just an older OPAL that doesn't
928 	 * know about that call
929 	 */
930 	if (rc && rc != OPAL_UNSUPPORTED)
931 		pr_warn("DUMP: Failed to register kernel log buffer. "
932 			"rc = %d\n", rc);
933 }
934 
opal_pdev_init(const char * compatible)935 static void __init opal_pdev_init(const char *compatible)
936 {
937 	struct device_node *np;
938 
939 	for_each_compatible_node(np, NULL, compatible)
940 		of_platform_device_create(np, NULL, NULL);
941 }
942 
opal_imc_init_dev(void)943 static void __init opal_imc_init_dev(void)
944 {
945 	struct device_node *np;
946 
947 	np = of_find_compatible_node(NULL, NULL, IMC_DTB_COMPAT);
948 	if (np)
949 		of_platform_device_create(np, NULL, NULL);
950 
951 	of_node_put(np);
952 }
953 
kopald(void * unused)954 static int kopald(void *unused)
955 {
956 	unsigned long timeout = msecs_to_jiffies(opal_heartbeat) + 1;
957 
958 	set_freezable();
959 	do {
960 		try_to_freeze();
961 
962 		opal_handle_events();
963 
964 		set_current_state(TASK_INTERRUPTIBLE);
965 		if (opal_have_pending_events())
966 			__set_current_state(TASK_RUNNING);
967 		else
968 			schedule_timeout(timeout);
969 
970 	} while (!kthread_should_stop());
971 
972 	return 0;
973 }
974 
opal_wake_poller(void)975 void opal_wake_poller(void)
976 {
977 	if (kopald_tsk)
978 		wake_up_process(kopald_tsk);
979 }
980 
opal_init_heartbeat(void)981 static void __init opal_init_heartbeat(void)
982 {
983 	/* Old firwmware, we assume the HVC heartbeat is sufficient */
984 	if (of_property_read_u32(opal_node, "ibm,heartbeat-ms",
985 				 &opal_heartbeat) != 0)
986 		opal_heartbeat = 0;
987 
988 	if (opal_heartbeat)
989 		kopald_tsk = kthread_run(kopald, NULL, "kopald");
990 }
991 
opal_init(void)992 static int __init opal_init(void)
993 {
994 	struct device_node *np, *consoles, *leds;
995 	int rc;
996 
997 	opal_node = of_find_node_by_path("/ibm,opal");
998 	if (!opal_node) {
999 		pr_warn("Device node not found\n");
1000 		return -ENODEV;
1001 	}
1002 
1003 	/* Register OPAL consoles if any ports */
1004 	consoles = of_find_node_by_path("/ibm,opal/consoles");
1005 	if (consoles) {
1006 		for_each_child_of_node(consoles, np) {
1007 			if (!of_node_name_eq(np, "serial"))
1008 				continue;
1009 			of_platform_device_create(np, NULL, NULL);
1010 		}
1011 		of_node_put(consoles);
1012 	}
1013 
1014 	/* Initialise OPAL messaging system */
1015 	opal_message_init(opal_node);
1016 
1017 	/* Initialise OPAL asynchronous completion interface */
1018 	opal_async_comp_init();
1019 
1020 	/* Initialise OPAL sensor interface */
1021 	opal_sensor_init();
1022 
1023 	/* Initialise OPAL hypervisor maintainence interrupt handling */
1024 	opal_hmi_handler_init();
1025 
1026 	/* Create i2c platform devices */
1027 	opal_pdev_init("ibm,opal-i2c");
1028 
1029 	/* Handle non-volatile memory devices */
1030 	opal_pdev_init("pmem-region");
1031 
1032 	/* Setup a heatbeat thread if requested by OPAL */
1033 	opal_init_heartbeat();
1034 
1035 	/* Detect In-Memory Collection counters and create devices*/
1036 	opal_imc_init_dev();
1037 
1038 	/* Create leds platform devices */
1039 	leds = of_find_node_by_path("/ibm,opal/leds");
1040 	if (leds) {
1041 		of_platform_device_create(leds, "opal_leds", NULL);
1042 		of_node_put(leds);
1043 	}
1044 
1045 	/* Initialise OPAL message log interface */
1046 	opal_msglog_init();
1047 
1048 	/* Create "opal" kobject under /sys/firmware */
1049 	rc = opal_sysfs_init();
1050 	if (rc == 0) {
1051 		/* Setup dump region interface */
1052 		opal_dump_region_init();
1053 		/* Setup error log interface */
1054 		rc = opal_elog_init();
1055 		/* Setup code update interface */
1056 		opal_flash_update_init();
1057 		/* Setup platform dump extract interface */
1058 		opal_platform_dump_init();
1059 		/* Setup system parameters interface */
1060 		opal_sys_param_init();
1061 		/* Setup message log sysfs interface. */
1062 		opal_msglog_sysfs_init();
1063 		/* Add all export properties*/
1064 		opal_export_attrs();
1065 	}
1066 
1067 	/* Initialize platform devices: IPMI backend, PRD & flash interface */
1068 	opal_pdev_init("ibm,opal-ipmi");
1069 	opal_pdev_init("ibm,opal-flash");
1070 	opal_pdev_init("ibm,opal-prd");
1071 
1072 	/* Initialise platform device: oppanel interface */
1073 	opal_pdev_init("ibm,opal-oppanel");
1074 
1075 	/* Initialise OPAL kmsg dumper for flushing console on panic */
1076 	opal_kmsg_init();
1077 
1078 	/* Initialise OPAL powercap interface */
1079 	opal_powercap_init();
1080 
1081 	/* Initialise OPAL Power-Shifting-Ratio interface */
1082 	opal_psr_init();
1083 
1084 	/* Initialise OPAL sensor groups */
1085 	opal_sensor_groups_init();
1086 
1087 	/* Initialise OPAL Power control interface */
1088 	opal_power_control_init();
1089 
1090 	/* Initialize OPAL secure variables */
1091 	opal_pdev_init("ibm,secvar-backend");
1092 
1093 	return 0;
1094 }
1095 machine_subsys_initcall(powernv, opal_init);
1096 
opal_shutdown(void)1097 void opal_shutdown(void)
1098 {
1099 	long rc = OPAL_BUSY;
1100 
1101 	opal_event_shutdown();
1102 
1103 	/*
1104 	 * Then sync with OPAL which ensure anything that can
1105 	 * potentially write to our memory has completed such
1106 	 * as an ongoing dump retrieval
1107 	 */
1108 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
1109 		rc = opal_sync_host_reboot();
1110 		if (rc == OPAL_BUSY)
1111 			opal_poll_events(NULL);
1112 		else
1113 			mdelay(10);
1114 	}
1115 
1116 	/* Unregister memory dump region */
1117 	if (opal_check_token(OPAL_UNREGISTER_DUMP_REGION))
1118 		opal_unregister_dump_region(OPAL_DUMP_REGION_LOG_BUF);
1119 }
1120 
1121 /* Export this so that test modules can use it */
1122 EXPORT_SYMBOL_GPL(opal_invalid_call);
1123 EXPORT_SYMBOL_GPL(opal_xscom_read);
1124 EXPORT_SYMBOL_GPL(opal_xscom_write);
1125 EXPORT_SYMBOL_GPL(opal_ipmi_send);
1126 EXPORT_SYMBOL_GPL(opal_ipmi_recv);
1127 EXPORT_SYMBOL_GPL(opal_flash_read);
1128 EXPORT_SYMBOL_GPL(opal_flash_write);
1129 EXPORT_SYMBOL_GPL(opal_flash_erase);
1130 EXPORT_SYMBOL_GPL(opal_prd_msg);
1131 EXPORT_SYMBOL_GPL(opal_check_token);
1132 
1133 /* Convert a region of vmalloc memory to an opal sg list */
opal_vmalloc_to_sg_list(void * vmalloc_addr,unsigned long vmalloc_size)1134 struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
1135 					     unsigned long vmalloc_size)
1136 {
1137 	struct opal_sg_list *sg, *first = NULL;
1138 	unsigned long i = 0;
1139 
1140 	sg = kzalloc(PAGE_SIZE, GFP_KERNEL);
1141 	if (!sg)
1142 		goto nomem;
1143 
1144 	first = sg;
1145 
1146 	while (vmalloc_size > 0) {
1147 		uint64_t data = vmalloc_to_pfn(vmalloc_addr) << PAGE_SHIFT;
1148 		uint64_t length = min(vmalloc_size, PAGE_SIZE);
1149 
1150 		sg->entry[i].data = cpu_to_be64(data);
1151 		sg->entry[i].length = cpu_to_be64(length);
1152 		i++;
1153 
1154 		if (i >= SG_ENTRIES_PER_NODE) {
1155 			struct opal_sg_list *next;
1156 
1157 			next = kzalloc(PAGE_SIZE, GFP_KERNEL);
1158 			if (!next)
1159 				goto nomem;
1160 
1161 			sg->length = cpu_to_be64(
1162 					i * sizeof(struct opal_sg_entry) + 16);
1163 			i = 0;
1164 			sg->next = cpu_to_be64(__pa(next));
1165 			sg = next;
1166 		}
1167 
1168 		vmalloc_addr += length;
1169 		vmalloc_size -= length;
1170 	}
1171 
1172 	sg->length = cpu_to_be64(i * sizeof(struct opal_sg_entry) + 16);
1173 
1174 	return first;
1175 
1176 nomem:
1177 	pr_err("%s : Failed to allocate memory\n", __func__);
1178 	opal_free_sg_list(first);
1179 	return NULL;
1180 }
1181 
opal_free_sg_list(struct opal_sg_list * sg)1182 void opal_free_sg_list(struct opal_sg_list *sg)
1183 {
1184 	while (sg) {
1185 		uint64_t next = be64_to_cpu(sg->next);
1186 
1187 		kfree(sg);
1188 
1189 		if (next)
1190 			sg = __va(next);
1191 		else
1192 			sg = NULL;
1193 	}
1194 }
1195 
opal_error_code(int rc)1196 int opal_error_code(int rc)
1197 {
1198 	switch (rc) {
1199 	case OPAL_SUCCESS:		return 0;
1200 
1201 	case OPAL_PARAMETER:		return -EINVAL;
1202 	case OPAL_ASYNC_COMPLETION:	return -EINPROGRESS;
1203 	case OPAL_BUSY:
1204 	case OPAL_BUSY_EVENT:		return -EBUSY;
1205 	case OPAL_NO_MEM:		return -ENOMEM;
1206 	case OPAL_PERMISSION:		return -EPERM;
1207 
1208 	case OPAL_UNSUPPORTED:		return -EIO;
1209 	case OPAL_HARDWARE:		return -EIO;
1210 	case OPAL_INTERNAL_ERROR:	return -EIO;
1211 	case OPAL_TIMEOUT:		return -ETIMEDOUT;
1212 	default:
1213 		pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
1214 		return -EIO;
1215 	}
1216 }
1217 
powernv_set_nmmu_ptcr(unsigned long ptcr)1218 void powernv_set_nmmu_ptcr(unsigned long ptcr)
1219 {
1220 	int rc;
1221 
1222 	if (firmware_has_feature(FW_FEATURE_OPAL)) {
1223 		rc = opal_nmmu_set_ptcr(-1UL, ptcr);
1224 		if (rc != OPAL_SUCCESS && rc != OPAL_UNSUPPORTED)
1225 			pr_warn("%s: Unable to set nest mmu ptcr\n", __func__);
1226 	}
1227 }
1228 
1229 EXPORT_SYMBOL_GPL(opal_poll_events);
1230 EXPORT_SYMBOL_GPL(opal_rtc_read);
1231 EXPORT_SYMBOL_GPL(opal_rtc_write);
1232 EXPORT_SYMBOL_GPL(opal_tpo_read);
1233 EXPORT_SYMBOL_GPL(opal_tpo_write);
1234 EXPORT_SYMBOL_GPL(opal_i2c_request);
1235 /* Export these symbols for PowerNV LED class driver */
1236 EXPORT_SYMBOL_GPL(opal_leds_get_ind);
1237 EXPORT_SYMBOL_GPL(opal_leds_set_ind);
1238 /* Export this symbol for PowerNV Operator Panel class driver */
1239 EXPORT_SYMBOL_GPL(opal_write_oppanel_async);
1240 /* Export this for KVM */
1241 EXPORT_SYMBOL_GPL(opal_int_set_mfrr);
1242 EXPORT_SYMBOL_GPL(opal_int_eoi);
1243 EXPORT_SYMBOL_GPL(opal_error_code);
1244 /* Export the below symbol for NX compression */
1245 EXPORT_SYMBOL(opal_nx_coproc_init);
1246