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