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 
30 #include <asm/machdep.h>
31 #include <asm/opal.h>
32 #include <asm/firmware.h>
33 #include <asm/mce.h>
34 #include <asm/imc-pmu.h>
35 
36 #include "powernv.h"
37 
38 /* /sys/firmware/opal */
39 struct kobject *opal_kobj;
40 
41 struct opal {
42 	u64 base;
43 	u64 entry;
44 	u64 size;
45 } opal;
46 
47 struct mcheck_recoverable_range {
48 	u64 start_addr;
49 	u64 end_addr;
50 	u64 recover_addr;
51 };
52 
53 static struct mcheck_recoverable_range *mc_recoverable_range;
54 static int mc_recoverable_range_len;
55 
56 struct device_node *opal_node;
57 static DEFINE_SPINLOCK(opal_write_lock);
58 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
59 static uint32_t opal_heartbeat;
60 static struct task_struct *kopald_tsk;
61 
62 void opal_configure_cores(void)
63 {
64 	u64 reinit_flags = 0;
65 
66 	/* Do the actual re-init, This will clobber all FPRs, VRs, etc...
67 	 *
68 	 * It will preserve non volatile GPRs and HSPRG0/1. It will
69 	 * also restore HIDs and other SPRs to their original value
70 	 * but it might clobber a bunch.
71 	 */
72 #ifdef __BIG_ENDIAN__
73 	reinit_flags |= OPAL_REINIT_CPUS_HILE_BE;
74 #else
75 	reinit_flags |= OPAL_REINIT_CPUS_HILE_LE;
76 #endif
77 
78 	/*
79 	 * POWER9 always support running hash:
80 	 *  ie. Host hash  supports  hash guests
81 	 *      Host radix supports  hash/radix guests
82 	 */
83 	if (early_cpu_has_feature(CPU_FTR_ARCH_300)) {
84 		reinit_flags |= OPAL_REINIT_CPUS_MMU_HASH;
85 		if (early_radix_enabled())
86 			reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX;
87 	}
88 
89 	opal_reinit_cpus(reinit_flags);
90 
91 	/* Restore some bits */
92 	if (cur_cpu_spec->cpu_restore)
93 		cur_cpu_spec->cpu_restore();
94 }
95 
96 int __init early_init_dt_scan_opal(unsigned long node,
97 				   const char *uname, int depth, void *data)
98 {
99 	const void *basep, *entryp, *sizep;
100 	int basesz, entrysz, runtimesz;
101 
102 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
103 		return 0;
104 
105 	basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
106 	entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
107 	sizep = of_get_flat_dt_prop(node, "opal-runtime-size", &runtimesz);
108 
109 	if (!basep || !entryp || !sizep)
110 		return 1;
111 
112 	opal.base = of_read_number(basep, basesz/4);
113 	opal.entry = of_read_number(entryp, entrysz/4);
114 	opal.size = of_read_number(sizep, runtimesz/4);
115 
116 	pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
117 		 opal.base, basep, basesz);
118 	pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
119 		 opal.entry, entryp, entrysz);
120 	pr_debug("OPAL Entry = 0x%llx (sizep=%p runtimesz=%d)\n",
121 		 opal.size, sizep, runtimesz);
122 
123 	if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
124 		powerpc_firmware_features |= FW_FEATURE_OPAL;
125 		pr_info("OPAL detected !\n");
126 	} else {
127 		panic("OPAL != V3 detected, no longer supported.\n");
128 	}
129 
130 	return 1;
131 }
132 
133 int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
134 				   const char *uname, int depth, void *data)
135 {
136 	int i, psize, size;
137 	const __be32 *prop;
138 
139 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
140 		return 0;
141 
142 	prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);
143 
144 	if (!prop)
145 		return 1;
146 
147 	pr_debug("Found machine check recoverable ranges.\n");
148 
149 	/*
150 	 * Calculate number of available entries.
151 	 *
152 	 * Each recoverable address range entry is (start address, len,
153 	 * recovery address), 2 cells each for start and recovery address,
154 	 * 1 cell for len, totalling 5 cells per entry.
155 	 */
156 	mc_recoverable_range_len = psize / (sizeof(*prop) * 5);
157 
158 	/* Sanity check */
159 	if (!mc_recoverable_range_len)
160 		return 1;
161 
162 	/* Size required to hold all the entries. */
163 	size = mc_recoverable_range_len *
164 			sizeof(struct mcheck_recoverable_range);
165 
166 	/*
167 	 * Allocate a buffer to hold the MC recoverable ranges. We would be
168 	 * accessing them in real mode, hence it needs to be within
169 	 * RMO region.
170 	 */
171 	mc_recoverable_range =__va(memblock_alloc_base(size, __alignof__(u64),
172 							ppc64_rma_size));
173 	memset(mc_recoverable_range, 0, size);
174 
175 	for (i = 0; i < mc_recoverable_range_len; i++) {
176 		mc_recoverable_range[i].start_addr =
177 					of_read_number(prop + (i * 5) + 0, 2);
178 		mc_recoverable_range[i].end_addr =
179 					mc_recoverable_range[i].start_addr +
180 					of_read_number(prop + (i * 5) + 2, 1);
181 		mc_recoverable_range[i].recover_addr =
182 					of_read_number(prop + (i * 5) + 3, 2);
183 
184 		pr_debug("Machine check recoverable range: %llx..%llx: %llx\n",
185 				mc_recoverable_range[i].start_addr,
186 				mc_recoverable_range[i].end_addr,
187 				mc_recoverable_range[i].recover_addr);
188 	}
189 	return 1;
190 }
191 
192 static int __init opal_register_exception_handlers(void)
193 {
194 #ifdef __BIG_ENDIAN__
195 	u64 glue;
196 
197 	if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
198 		return -ENODEV;
199 
200 	/* Hookup some exception handlers except machine check. We use the
201 	 * fwnmi area at 0x7000 to provide the glue space to OPAL
202 	 */
203 	glue = 0x7000;
204 
205 	/*
206 	 * Check if we are running on newer firmware that exports
207 	 * OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to patch
208 	 * the HMI interrupt and we catch it directly in Linux.
209 	 *
210 	 * For older firmware (i.e currently released POWER8 System Firmware
211 	 * as of today <= SV810_087), we fallback to old behavior and let OPAL
212 	 * patch the HMI vector and handle it inside OPAL firmware.
213 	 *
214 	 * For newer firmware (in development/yet to be released) we will
215 	 * start catching/handling HMI directly in Linux.
216 	 */
217 	if (!opal_check_token(OPAL_HANDLE_HMI)) {
218 		pr_info("Old firmware detected, OPAL handles HMIs.\n");
219 		opal_register_exception_handler(
220 				OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
221 				0, glue);
222 		glue += 128;
223 	}
224 
225 	opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
226 #endif
227 
228 	return 0;
229 }
230 machine_early_initcall(powernv, opal_register_exception_handlers);
231 
232 /*
233  * Opal message notifier based on message type. Allow subscribers to get
234  * notified for specific messgae type.
235  */
236 int opal_message_notifier_register(enum opal_msg_type msg_type,
237 					struct notifier_block *nb)
238 {
239 	if (!nb || msg_type >= OPAL_MSG_TYPE_MAX) {
240 		pr_warning("%s: Invalid arguments, msg_type:%d\n",
241 			   __func__, msg_type);
242 		return -EINVAL;
243 	}
244 
245 	return atomic_notifier_chain_register(
246 				&opal_msg_notifier_head[msg_type], nb);
247 }
248 EXPORT_SYMBOL_GPL(opal_message_notifier_register);
249 
250 int opal_message_notifier_unregister(enum opal_msg_type msg_type,
251 				     struct notifier_block *nb)
252 {
253 	return atomic_notifier_chain_unregister(
254 			&opal_msg_notifier_head[msg_type], nb);
255 }
256 EXPORT_SYMBOL_GPL(opal_message_notifier_unregister);
257 
258 static void opal_message_do_notify(uint32_t msg_type, void *msg)
259 {
260 	/* notify subscribers */
261 	atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
262 					msg_type, msg);
263 }
264 
265 static void opal_handle_message(void)
266 {
267 	s64 ret;
268 	/*
269 	 * TODO: pre-allocate a message buffer depending on opal-msg-size
270 	 * value in /proc/device-tree.
271 	 */
272 	static struct opal_msg msg;
273 	u32 type;
274 
275 	ret = opal_get_msg(__pa(&msg), sizeof(msg));
276 	/* No opal message pending. */
277 	if (ret == OPAL_RESOURCE)
278 		return;
279 
280 	/* check for errors. */
281 	if (ret) {
282 		pr_warning("%s: Failed to retrieve opal message, err=%lld\n",
283 				__func__, ret);
284 		return;
285 	}
286 
287 	type = be32_to_cpu(msg.msg_type);
288 
289 	/* Sanity check */
290 	if (type >= OPAL_MSG_TYPE_MAX) {
291 		pr_warn_once("%s: Unknown message type: %u\n", __func__, type);
292 		return;
293 	}
294 	opal_message_do_notify(type, (void *)&msg);
295 }
296 
297 static irqreturn_t opal_message_notify(int irq, void *data)
298 {
299 	opal_handle_message();
300 	return IRQ_HANDLED;
301 }
302 
303 static int __init opal_message_init(void)
304 {
305 	int ret, i, irq;
306 
307 	for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
308 		ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
309 
310 	irq = opal_event_request(ilog2(OPAL_EVENT_MSG_PENDING));
311 	if (!irq) {
312 		pr_err("%s: Can't register OPAL event irq (%d)\n",
313 		       __func__, irq);
314 		return irq;
315 	}
316 
317 	ret = request_irq(irq, opal_message_notify,
318 			IRQ_TYPE_LEVEL_HIGH, "opal-msg", NULL);
319 	if (ret) {
320 		pr_err("%s: Can't request OPAL event irq (%d)\n",
321 		       __func__, ret);
322 		return ret;
323 	}
324 
325 	return 0;
326 }
327 
328 int opal_get_chars(uint32_t vtermno, char *buf, int count)
329 {
330 	s64 rc;
331 	__be64 evt, len;
332 
333 	if (!opal.entry)
334 		return -ENODEV;
335 	opal_poll_events(&evt);
336 	if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
337 		return 0;
338 	len = cpu_to_be64(count);
339 	rc = opal_console_read(vtermno, &len, buf);
340 	if (rc == OPAL_SUCCESS)
341 		return be64_to_cpu(len);
342 	return 0;
343 }
344 
345 int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
346 {
347 	int written = 0;
348 	__be64 olen;
349 	s64 len, rc;
350 	unsigned long flags;
351 	__be64 evt;
352 
353 	if (!opal.entry)
354 		return -ENODEV;
355 
356 	/* We want put_chars to be atomic to avoid mangling of hvsi
357 	 * packets. To do that, we first test for room and return
358 	 * -EAGAIN if there isn't enough.
359 	 *
360 	 * Unfortunately, opal_console_write_buffer_space() doesn't
361 	 * appear to work on opal v1, so we just assume there is
362 	 * enough room and be done with it
363 	 */
364 	spin_lock_irqsave(&opal_write_lock, flags);
365 	rc = opal_console_write_buffer_space(vtermno, &olen);
366 	len = be64_to_cpu(olen);
367 	if (rc || len < total_len) {
368 		spin_unlock_irqrestore(&opal_write_lock, flags);
369 		/* Closed -> drop characters */
370 		if (rc)
371 			return total_len;
372 		opal_poll_events(NULL);
373 		return -EAGAIN;
374 	}
375 
376 	/* We still try to handle partial completions, though they
377 	 * should no longer happen.
378 	 */
379 	rc = OPAL_BUSY;
380 	while(total_len > 0 && (rc == OPAL_BUSY ||
381 				rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
382 		olen = cpu_to_be64(total_len);
383 		rc = opal_console_write(vtermno, &olen, data);
384 		len = be64_to_cpu(olen);
385 
386 		/* Closed or other error drop */
387 		if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
388 		    rc != OPAL_BUSY_EVENT) {
389 			written = total_len;
390 			break;
391 		}
392 		if (rc == OPAL_SUCCESS) {
393 			total_len -= len;
394 			data += len;
395 			written += len;
396 		}
397 		/* This is a bit nasty but we need that for the console to
398 		 * flush when there aren't any interrupts. We will clean
399 		 * things a bit later to limit that to synchronous path
400 		 * such as the kernel console and xmon/udbg
401 		 */
402 		do
403 			opal_poll_events(&evt);
404 		while(rc == OPAL_SUCCESS &&
405 			(be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));
406 	}
407 	spin_unlock_irqrestore(&opal_write_lock, flags);
408 	return written;
409 }
410 
411 static int opal_recover_mce(struct pt_regs *regs,
412 					struct machine_check_event *evt)
413 {
414 	int recovered = 0;
415 
416 	if (!(regs->msr & MSR_RI)) {
417 		/* If MSR_RI isn't set, we cannot recover */
418 		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
419 		recovered = 0;
420 	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
421 		/* Platform corrected itself */
422 		recovered = 1;
423 	} else if (evt->severity == MCE_SEV_FATAL) {
424 		/* Fatal machine check */
425 		pr_err("Machine check interrupt is fatal\n");
426 		recovered = 0;
427 	} else if ((evt->severity == MCE_SEV_ERROR_SYNC) &&
428 			(user_mode(regs) && !is_global_init(current))) {
429 		/*
430 		 * For now, kill the task if we have received exception when
431 		 * in userspace.
432 		 *
433 		 * TODO: Queue up this address for hwpoisioning later.
434 		 */
435 		_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
436 		recovered = 1;
437 	}
438 	return recovered;
439 }
440 
441 int opal_machine_check(struct pt_regs *regs)
442 {
443 	struct machine_check_event evt;
444 	int ret;
445 
446 	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
447 		return 0;
448 
449 	/* Print things out */
450 	if (evt.version != MCE_V1) {
451 		pr_err("Machine Check Exception, Unknown event version %d !\n",
452 		       evt.version);
453 		return 0;
454 	}
455 	machine_check_print_event_info(&evt, user_mode(regs));
456 
457 	if (opal_recover_mce(regs, &evt))
458 		return 1;
459 
460 	/*
461 	 * Unrecovered machine check, we are heading to panic path.
462 	 *
463 	 * We may have hit this MCE in very early stage of kernel
464 	 * initialization even before opal-prd has started running. If
465 	 * this is the case then this MCE error may go un-noticed or
466 	 * un-analyzed if we go down panic path. We need to inform
467 	 * BMC/OCC about this error so that they can collect relevant
468 	 * data for error analysis before rebooting.
469 	 * Use opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR) to do so.
470 	 * This function may not return on BMC based system.
471 	 */
472 	ret = opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR,
473 			"Unrecoverable Machine Check exception");
474 	if (ret == OPAL_UNSUPPORTED) {
475 		pr_emerg("Reboot type %d not supported\n",
476 					OPAL_REBOOT_PLATFORM_ERROR);
477 	}
478 
479 	/*
480 	 * We reached here. There can be three possibilities:
481 	 * 1. We are running on a firmware level that do not support
482 	 *    opal_cec_reboot2()
483 	 * 2. We are running on a firmware level that do not support
484 	 *    OPAL_REBOOT_PLATFORM_ERROR reboot type.
485 	 * 3. We are running on FSP based system that does not need opal
486 	 *    to trigger checkstop explicitly for error analysis. The FSP
487 	 *    PRD component would have already got notified about this
488 	 *    error through other channels.
489 	 *
490 	 * If hardware marked this as an unrecoverable MCE, we are
491 	 * going to panic anyway. Even if it didn't, it's not safe to
492 	 * continue at this point, so we should explicitly panic.
493 	 */
494 
495 	panic("PowerNV Unrecovered Machine Check");
496 	return 0;
497 }
498 
499 /* Early hmi handler called in real mode. */
500 int opal_hmi_exception_early(struct pt_regs *regs)
501 {
502 	s64 rc;
503 
504 	/*
505 	 * call opal hmi handler. Pass paca address as token.
506 	 * The return value OPAL_SUCCESS is an indication that there is
507 	 * an HMI event generated waiting to pull by Linux.
508 	 */
509 	rc = opal_handle_hmi();
510 	if (rc == OPAL_SUCCESS) {
511 		local_paca->hmi_event_available = 1;
512 		return 1;
513 	}
514 	return 0;
515 }
516 
517 /* HMI exception handler called in virtual mode during check_irq_replay. */
518 int opal_handle_hmi_exception(struct pt_regs *regs)
519 {
520 	s64 rc;
521 	__be64 evt = 0;
522 
523 	/*
524 	 * Check if HMI event is available.
525 	 * if Yes, then call opal_poll_events to pull opal messages and
526 	 * process them.
527 	 */
528 	if (!local_paca->hmi_event_available)
529 		return 0;
530 
531 	local_paca->hmi_event_available = 0;
532 	rc = opal_poll_events(&evt);
533 	if (rc == OPAL_SUCCESS && evt)
534 		opal_handle_events(be64_to_cpu(evt));
535 
536 	return 1;
537 }
538 
539 static uint64_t find_recovery_address(uint64_t nip)
540 {
541 	int i;
542 
543 	for (i = 0; i < mc_recoverable_range_len; i++)
544 		if ((nip >= mc_recoverable_range[i].start_addr) &&
545 		    (nip < mc_recoverable_range[i].end_addr))
546 		    return mc_recoverable_range[i].recover_addr;
547 	return 0;
548 }
549 
550 bool opal_mce_check_early_recovery(struct pt_regs *regs)
551 {
552 	uint64_t recover_addr = 0;
553 
554 	if (!opal.base || !opal.size)
555 		goto out;
556 
557 	if ((regs->nip >= opal.base) &&
558 			(regs->nip < (opal.base + opal.size)))
559 		recover_addr = find_recovery_address(regs->nip);
560 
561 	/*
562 	 * Setup regs->nip to rfi into fixup address.
563 	 */
564 	if (recover_addr)
565 		regs->nip = recover_addr;
566 
567 out:
568 	return !!recover_addr;
569 }
570 
571 static int opal_sysfs_init(void)
572 {
573 	opal_kobj = kobject_create_and_add("opal", firmware_kobj);
574 	if (!opal_kobj) {
575 		pr_warn("kobject_create_and_add opal failed\n");
576 		return -ENOMEM;
577 	}
578 
579 	return 0;
580 }
581 
582 static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj,
583 			       struct bin_attribute *bin_attr,
584 			       char *buf, loff_t off, size_t count)
585 {
586 	return memory_read_from_buffer(buf, count, &off, bin_attr->private,
587 				       bin_attr->size);
588 }
589 
590 static BIN_ATTR_RO(symbol_map, 0);
591 
592 static void opal_export_symmap(void)
593 {
594 	const __be64 *syms;
595 	unsigned int size;
596 	struct device_node *fw;
597 	int rc;
598 
599 	fw = of_find_node_by_path("/ibm,opal/firmware");
600 	if (!fw)
601 		return;
602 	syms = of_get_property(fw, "symbol-map", &size);
603 	if (!syms || size != 2 * sizeof(__be64))
604 		return;
605 
606 	/* Setup attributes */
607 	bin_attr_symbol_map.private = __va(be64_to_cpu(syms[0]));
608 	bin_attr_symbol_map.size = be64_to_cpu(syms[1]);
609 
610 	rc = sysfs_create_bin_file(opal_kobj, &bin_attr_symbol_map);
611 	if (rc)
612 		pr_warn("Error %d creating OPAL symbols file\n", rc);
613 }
614 
615 static ssize_t export_attr_read(struct file *fp, struct kobject *kobj,
616 				struct bin_attribute *bin_attr, char *buf,
617 				loff_t off, size_t count)
618 {
619 	return memory_read_from_buffer(buf, count, &off, bin_attr->private,
620 				       bin_attr->size);
621 }
622 
623 /*
624  * opal_export_attrs: creates a sysfs node for each property listed in
625  * the device-tree under /ibm,opal/firmware/exports/
626  * All new sysfs nodes are created under /opal/exports/.
627  * This allows for reserved memory regions (e.g. HDAT) to be read.
628  * The new sysfs nodes are only readable by root.
629  */
630 static void opal_export_attrs(void)
631 {
632 	struct bin_attribute *attr;
633 	struct device_node *np;
634 	struct property *prop;
635 	struct kobject *kobj;
636 	u64 vals[2];
637 	int rc;
638 
639 	np = of_find_node_by_path("/ibm,opal/firmware/exports");
640 	if (!np)
641 		return;
642 
643 	/* Create new 'exports' directory - /sys/firmware/opal/exports */
644 	kobj = kobject_create_and_add("exports", opal_kobj);
645 	if (!kobj) {
646 		pr_warn("kobject_create_and_add() of exports failed\n");
647 		return;
648 	}
649 
650 	for_each_property_of_node(np, prop) {
651 		if (!strcmp(prop->name, "name") || !strcmp(prop->name, "phandle"))
652 			continue;
653 
654 		if (of_property_read_u64_array(np, prop->name, &vals[0], 2))
655 			continue;
656 
657 		attr = kzalloc(sizeof(*attr), GFP_KERNEL);
658 
659 		if (attr == NULL) {
660 			pr_warn("Failed kmalloc for bin_attribute!");
661 			continue;
662 		}
663 
664 		sysfs_bin_attr_init(attr);
665 		attr->attr.name = kstrdup(prop->name, GFP_KERNEL);
666 		attr->attr.mode = 0400;
667 		attr->read = export_attr_read;
668 		attr->private = __va(vals[0]);
669 		attr->size = vals[1];
670 
671 		if (attr->attr.name == NULL) {
672 			pr_warn("Failed kstrdup for bin_attribute attr.name");
673 			kfree(attr);
674 			continue;
675 		}
676 
677 		rc = sysfs_create_bin_file(kobj, attr);
678 		if (rc) {
679 			pr_warn("Error %d creating OPAL sysfs exports/%s file\n",
680 				 rc, prop->name);
681 			kfree(attr->attr.name);
682 			kfree(attr);
683 		}
684 	}
685 
686 	of_node_put(np);
687 }
688 
689 static void __init opal_dump_region_init(void)
690 {
691 	void *addr;
692 	uint64_t size;
693 	int rc;
694 
695 	if (!opal_check_token(OPAL_REGISTER_DUMP_REGION))
696 		return;
697 
698 	/* Register kernel log buffer */
699 	addr = log_buf_addr_get();
700 	if (addr == NULL)
701 		return;
702 
703 	size = log_buf_len_get();
704 	if (size == 0)
705 		return;
706 
707 	rc = opal_register_dump_region(OPAL_DUMP_REGION_LOG_BUF,
708 				       __pa(addr), size);
709 	/* Don't warn if this is just an older OPAL that doesn't
710 	 * know about that call
711 	 */
712 	if (rc && rc != OPAL_UNSUPPORTED)
713 		pr_warn("DUMP: Failed to register kernel log buffer. "
714 			"rc = %d\n", rc);
715 }
716 
717 static void opal_pdev_init(const char *compatible)
718 {
719 	struct device_node *np;
720 
721 	for_each_compatible_node(np, NULL, compatible)
722 		of_platform_device_create(np, NULL, NULL);
723 }
724 
725 static void __init opal_imc_init_dev(void)
726 {
727 	struct device_node *np;
728 
729 	np = of_find_compatible_node(NULL, NULL, IMC_DTB_COMPAT);
730 	if (np)
731 		of_platform_device_create(np, NULL, NULL);
732 }
733 
734 static int kopald(void *unused)
735 {
736 	unsigned long timeout = msecs_to_jiffies(opal_heartbeat) + 1;
737 	__be64 events;
738 
739 	set_freezable();
740 	do {
741 		try_to_freeze();
742 		opal_poll_events(&events);
743 		opal_handle_events(be64_to_cpu(events));
744 		schedule_timeout_interruptible(timeout);
745 	} while (!kthread_should_stop());
746 
747 	return 0;
748 }
749 
750 void opal_wake_poller(void)
751 {
752 	if (kopald_tsk)
753 		wake_up_process(kopald_tsk);
754 }
755 
756 static void opal_init_heartbeat(void)
757 {
758 	/* Old firwmware, we assume the HVC heartbeat is sufficient */
759 	if (of_property_read_u32(opal_node, "ibm,heartbeat-ms",
760 				 &opal_heartbeat) != 0)
761 		opal_heartbeat = 0;
762 
763 	if (opal_heartbeat)
764 		kopald_tsk = kthread_run(kopald, NULL, "kopald");
765 }
766 
767 static int __init opal_init(void)
768 {
769 	struct device_node *np, *consoles, *leds;
770 	int rc;
771 
772 	opal_node = of_find_node_by_path("/ibm,opal");
773 	if (!opal_node) {
774 		pr_warn("Device node not found\n");
775 		return -ENODEV;
776 	}
777 
778 	/* Register OPAL consoles if any ports */
779 	consoles = of_find_node_by_path("/ibm,opal/consoles");
780 	if (consoles) {
781 		for_each_child_of_node(consoles, np) {
782 			if (strcmp(np->name, "serial"))
783 				continue;
784 			of_platform_device_create(np, NULL, NULL);
785 		}
786 		of_node_put(consoles);
787 	}
788 
789 	/* Initialise OPAL messaging system */
790 	opal_message_init();
791 
792 	/* Initialise OPAL asynchronous completion interface */
793 	opal_async_comp_init();
794 
795 	/* Initialise OPAL sensor interface */
796 	opal_sensor_init();
797 
798 	/* Initialise OPAL hypervisor maintainence interrupt handling */
799 	opal_hmi_handler_init();
800 
801 	/* Create i2c platform devices */
802 	opal_pdev_init("ibm,opal-i2c");
803 
804 	/* Setup a heatbeat thread if requested by OPAL */
805 	opal_init_heartbeat();
806 
807 	/* Detect In-Memory Collection counters and create devices*/
808 	opal_imc_init_dev();
809 
810 	/* Create leds platform devices */
811 	leds = of_find_node_by_path("/ibm,opal/leds");
812 	if (leds) {
813 		of_platform_device_create(leds, "opal_leds", NULL);
814 		of_node_put(leds);
815 	}
816 
817 	/* Initialise OPAL message log interface */
818 	opal_msglog_init();
819 
820 	/* Create "opal" kobject under /sys/firmware */
821 	rc = opal_sysfs_init();
822 	if (rc == 0) {
823 		/* Export symbol map to userspace */
824 		opal_export_symmap();
825 		/* Setup dump region interface */
826 		opal_dump_region_init();
827 		/* Setup error log interface */
828 		rc = opal_elog_init();
829 		/* Setup code update interface */
830 		opal_flash_update_init();
831 		/* Setup platform dump extract interface */
832 		opal_platform_dump_init();
833 		/* Setup system parameters interface */
834 		opal_sys_param_init();
835 		/* Setup message log sysfs interface. */
836 		opal_msglog_sysfs_init();
837 	}
838 
839 	/* Export all properties */
840 	opal_export_attrs();
841 
842 	/* Initialize platform devices: IPMI backend, PRD & flash interface */
843 	opal_pdev_init("ibm,opal-ipmi");
844 	opal_pdev_init("ibm,opal-flash");
845 	opal_pdev_init("ibm,opal-prd");
846 
847 	/* Initialise platform device: oppanel interface */
848 	opal_pdev_init("ibm,opal-oppanel");
849 
850 	/* Initialise OPAL kmsg dumper for flushing console on panic */
851 	opal_kmsg_init();
852 
853 	/* Initialise OPAL powercap interface */
854 	opal_powercap_init();
855 
856 	/* Initialise OPAL Power-Shifting-Ratio interface */
857 	opal_psr_init();
858 
859 	return 0;
860 }
861 machine_subsys_initcall(powernv, opal_init);
862 
863 void opal_shutdown(void)
864 {
865 	long rc = OPAL_BUSY;
866 
867 	opal_event_shutdown();
868 
869 	/*
870 	 * Then sync with OPAL which ensure anything that can
871 	 * potentially write to our memory has completed such
872 	 * as an ongoing dump retrieval
873 	 */
874 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
875 		rc = opal_sync_host_reboot();
876 		if (rc == OPAL_BUSY)
877 			opal_poll_events(NULL);
878 		else
879 			mdelay(10);
880 	}
881 
882 	/* Unregister memory dump region */
883 	if (opal_check_token(OPAL_UNREGISTER_DUMP_REGION))
884 		opal_unregister_dump_region(OPAL_DUMP_REGION_LOG_BUF);
885 }
886 
887 /* Export this so that test modules can use it */
888 EXPORT_SYMBOL_GPL(opal_invalid_call);
889 EXPORT_SYMBOL_GPL(opal_xscom_read);
890 EXPORT_SYMBOL_GPL(opal_xscom_write);
891 EXPORT_SYMBOL_GPL(opal_ipmi_send);
892 EXPORT_SYMBOL_GPL(opal_ipmi_recv);
893 EXPORT_SYMBOL_GPL(opal_flash_read);
894 EXPORT_SYMBOL_GPL(opal_flash_write);
895 EXPORT_SYMBOL_GPL(opal_flash_erase);
896 EXPORT_SYMBOL_GPL(opal_prd_msg);
897 
898 /* Convert a region of vmalloc memory to an opal sg list */
899 struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
900 					     unsigned long vmalloc_size)
901 {
902 	struct opal_sg_list *sg, *first = NULL;
903 	unsigned long i = 0;
904 
905 	sg = kzalloc(PAGE_SIZE, GFP_KERNEL);
906 	if (!sg)
907 		goto nomem;
908 
909 	first = sg;
910 
911 	while (vmalloc_size > 0) {
912 		uint64_t data = vmalloc_to_pfn(vmalloc_addr) << PAGE_SHIFT;
913 		uint64_t length = min(vmalloc_size, PAGE_SIZE);
914 
915 		sg->entry[i].data = cpu_to_be64(data);
916 		sg->entry[i].length = cpu_to_be64(length);
917 		i++;
918 
919 		if (i >= SG_ENTRIES_PER_NODE) {
920 			struct opal_sg_list *next;
921 
922 			next = kzalloc(PAGE_SIZE, GFP_KERNEL);
923 			if (!next)
924 				goto nomem;
925 
926 			sg->length = cpu_to_be64(
927 					i * sizeof(struct opal_sg_entry) + 16);
928 			i = 0;
929 			sg->next = cpu_to_be64(__pa(next));
930 			sg = next;
931 		}
932 
933 		vmalloc_addr += length;
934 		vmalloc_size -= length;
935 	}
936 
937 	sg->length = cpu_to_be64(i * sizeof(struct opal_sg_entry) + 16);
938 
939 	return first;
940 
941 nomem:
942 	pr_err("%s : Failed to allocate memory\n", __func__);
943 	opal_free_sg_list(first);
944 	return NULL;
945 }
946 
947 void opal_free_sg_list(struct opal_sg_list *sg)
948 {
949 	while (sg) {
950 		uint64_t next = be64_to_cpu(sg->next);
951 
952 		kfree(sg);
953 
954 		if (next)
955 			sg = __va(next);
956 		else
957 			sg = NULL;
958 	}
959 }
960 
961 int opal_error_code(int rc)
962 {
963 	switch (rc) {
964 	case OPAL_SUCCESS:		return 0;
965 
966 	case OPAL_PARAMETER:		return -EINVAL;
967 	case OPAL_ASYNC_COMPLETION:	return -EINPROGRESS;
968 	case OPAL_BUSY_EVENT:		return -EBUSY;
969 	case OPAL_NO_MEM:		return -ENOMEM;
970 	case OPAL_PERMISSION:		return -EPERM;
971 
972 	case OPAL_UNSUPPORTED:		return -EIO;
973 	case OPAL_HARDWARE:		return -EIO;
974 	case OPAL_INTERNAL_ERROR:	return -EIO;
975 	case OPAL_TIMEOUT:		return -ETIMEDOUT;
976 	default:
977 		pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
978 		return -EIO;
979 	}
980 }
981 
982 void powernv_set_nmmu_ptcr(unsigned long ptcr)
983 {
984 	int rc;
985 
986 	if (firmware_has_feature(FW_FEATURE_OPAL)) {
987 		rc = opal_nmmu_set_ptcr(-1UL, ptcr);
988 		if (rc != OPAL_SUCCESS && rc != OPAL_UNSUPPORTED)
989 			pr_warn("%s: Unable to set nest mmu ptcr\n", __func__);
990 	}
991 }
992 
993 EXPORT_SYMBOL_GPL(opal_poll_events);
994 EXPORT_SYMBOL_GPL(opal_rtc_read);
995 EXPORT_SYMBOL_GPL(opal_rtc_write);
996 EXPORT_SYMBOL_GPL(opal_tpo_read);
997 EXPORT_SYMBOL_GPL(opal_tpo_write);
998 EXPORT_SYMBOL_GPL(opal_i2c_request);
999 /* Export these symbols for PowerNV LED class driver */
1000 EXPORT_SYMBOL_GPL(opal_leds_get_ind);
1001 EXPORT_SYMBOL_GPL(opal_leds_set_ind);
1002 /* Export this symbol for PowerNV Operator Panel class driver */
1003 EXPORT_SYMBOL_GPL(opal_write_oppanel_async);
1004 /* Export this for KVM */
1005 EXPORT_SYMBOL_GPL(opal_int_set_mfrr);
1006 EXPORT_SYMBOL_GPL(opal_int_eoi);
1007