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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/interrupt.h>
20 #include <linux/notifier.h>
21 #include <linux/slab.h>
22 #include <linux/sched.h>
23 #include <linux/kobject.h>
24 #include <linux/delay.h>
25 #include <linux/memblock.h>
26 #include <linux/kthread.h>
27 #include <linux/freezer.h>
28 
29 #include <asm/machdep.h>
30 #include <asm/opal.h>
31 #include <asm/firmware.h>
32 #include <asm/mce.h>
33 
34 #include "powernv.h"
35 
36 /* /sys/firmware/opal */
37 struct kobject *opal_kobj;
38 
39 struct opal {
40 	u64 base;
41 	u64 entry;
42 	u64 size;
43 } opal;
44 
45 struct mcheck_recoverable_range {
46 	u64 start_addr;
47 	u64 end_addr;
48 	u64 recover_addr;
49 };
50 
51 static struct mcheck_recoverable_range *mc_recoverable_range;
52 static int mc_recoverable_range_len;
53 
54 struct device_node *opal_node;
55 static DEFINE_SPINLOCK(opal_write_lock);
56 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
57 static uint32_t opal_heartbeat;
58 
opal_reinit_cores(void)59 static void opal_reinit_cores(void)
60 {
61 	/* Do the actual re-init, This will clobber all FPRs, VRs, etc...
62 	 *
63 	 * It will preserve non volatile GPRs and HSPRG0/1. It will
64 	 * also restore HIDs and other SPRs to their original value
65 	 * but it might clobber a bunch.
66 	 */
67 #ifdef __BIG_ENDIAN__
68 	opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_BE);
69 #else
70 	opal_reinit_cpus(OPAL_REINIT_CPUS_HILE_LE);
71 #endif
72 }
73 
early_init_dt_scan_opal(unsigned long node,const char * uname,int depth,void * data)74 int __init early_init_dt_scan_opal(unsigned long node,
75 				   const char *uname, int depth, void *data)
76 {
77 	const void *basep, *entryp, *sizep;
78 	int basesz, entrysz, runtimesz;
79 
80 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
81 		return 0;
82 
83 	basep  = of_get_flat_dt_prop(node, "opal-base-address", &basesz);
84 	entryp = of_get_flat_dt_prop(node, "opal-entry-address", &entrysz);
85 	sizep = of_get_flat_dt_prop(node, "opal-runtime-size", &runtimesz);
86 
87 	if (!basep || !entryp || !sizep)
88 		return 1;
89 
90 	opal.base = of_read_number(basep, basesz/4);
91 	opal.entry = of_read_number(entryp, entrysz/4);
92 	opal.size = of_read_number(sizep, runtimesz/4);
93 
94 	pr_debug("OPAL Base  = 0x%llx (basep=%p basesz=%d)\n",
95 		 opal.base, basep, basesz);
96 	pr_debug("OPAL Entry = 0x%llx (entryp=%p basesz=%d)\n",
97 		 opal.entry, entryp, entrysz);
98 	pr_debug("OPAL Entry = 0x%llx (sizep=%p runtimesz=%d)\n",
99 		 opal.size, sizep, runtimesz);
100 
101 	if (of_flat_dt_is_compatible(node, "ibm,opal-v3")) {
102 		powerpc_firmware_features |= FW_FEATURE_OPAL;
103 		pr_info("OPAL detected !\n");
104 	} else {
105 		panic("OPAL != V3 detected, no longer supported.\n");
106 	}
107 
108 	/* Reinit all cores with the right endian */
109 	opal_reinit_cores();
110 
111 	/* Restore some bits */
112 	if (cur_cpu_spec->cpu_restore)
113 		cur_cpu_spec->cpu_restore();
114 
115 	return 1;
116 }
117 
early_init_dt_scan_recoverable_ranges(unsigned long node,const char * uname,int depth,void * data)118 int __init early_init_dt_scan_recoverable_ranges(unsigned long node,
119 				   const char *uname, int depth, void *data)
120 {
121 	int i, psize, size;
122 	const __be32 *prop;
123 
124 	if (depth != 1 || strcmp(uname, "ibm,opal") != 0)
125 		return 0;
126 
127 	prop = of_get_flat_dt_prop(node, "mcheck-recoverable-ranges", &psize);
128 
129 	if (!prop)
130 		return 1;
131 
132 	pr_debug("Found machine check recoverable ranges.\n");
133 
134 	/*
135 	 * Calculate number of available entries.
136 	 *
137 	 * Each recoverable address range entry is (start address, len,
138 	 * recovery address), 2 cells each for start and recovery address,
139 	 * 1 cell for len, totalling 5 cells per entry.
140 	 */
141 	mc_recoverable_range_len = psize / (sizeof(*prop) * 5);
142 
143 	/* Sanity check */
144 	if (!mc_recoverable_range_len)
145 		return 1;
146 
147 	/* Size required to hold all the entries. */
148 	size = mc_recoverable_range_len *
149 			sizeof(struct mcheck_recoverable_range);
150 
151 	/*
152 	 * Allocate a buffer to hold the MC recoverable ranges. We would be
153 	 * accessing them in real mode, hence it needs to be within
154 	 * RMO region.
155 	 */
156 	mc_recoverable_range =__va(memblock_alloc_base(size, __alignof__(u64),
157 							ppc64_rma_size));
158 	memset(mc_recoverable_range, 0, size);
159 
160 	for (i = 0; i < mc_recoverable_range_len; i++) {
161 		mc_recoverable_range[i].start_addr =
162 					of_read_number(prop + (i * 5) + 0, 2);
163 		mc_recoverable_range[i].end_addr =
164 					mc_recoverable_range[i].start_addr +
165 					of_read_number(prop + (i * 5) + 2, 1);
166 		mc_recoverable_range[i].recover_addr =
167 					of_read_number(prop + (i * 5) + 3, 2);
168 
169 		pr_debug("Machine check recoverable range: %llx..%llx: %llx\n",
170 				mc_recoverable_range[i].start_addr,
171 				mc_recoverable_range[i].end_addr,
172 				mc_recoverable_range[i].recover_addr);
173 	}
174 	return 1;
175 }
176 
opal_register_exception_handlers(void)177 static int __init opal_register_exception_handlers(void)
178 {
179 #ifdef __BIG_ENDIAN__
180 	u64 glue;
181 
182 	if (!(powerpc_firmware_features & FW_FEATURE_OPAL))
183 		return -ENODEV;
184 
185 	/* Hookup some exception handlers except machine check. We use the
186 	 * fwnmi area at 0x7000 to provide the glue space to OPAL
187 	 */
188 	glue = 0x7000;
189 
190 	/*
191 	 * Check if we are running on newer firmware that exports
192 	 * OPAL_HANDLE_HMI token. If yes, then don't ask OPAL to patch
193 	 * the HMI interrupt and we catch it directly in Linux.
194 	 *
195 	 * For older firmware (i.e currently released POWER8 System Firmware
196 	 * as of today <= SV810_087), we fallback to old behavior and let OPAL
197 	 * patch the HMI vector and handle it inside OPAL firmware.
198 	 *
199 	 * For newer firmware (in development/yet to be released) we will
200 	 * start catching/handling HMI directly in Linux.
201 	 */
202 	if (!opal_check_token(OPAL_HANDLE_HMI)) {
203 		pr_info("Old firmware detected, OPAL handles HMIs.\n");
204 		opal_register_exception_handler(
205 				OPAL_HYPERVISOR_MAINTENANCE_HANDLER,
206 				0, glue);
207 		glue += 128;
208 	}
209 
210 	opal_register_exception_handler(OPAL_SOFTPATCH_HANDLER, 0, glue);
211 #endif
212 
213 	return 0;
214 }
215 machine_early_initcall(powernv, opal_register_exception_handlers);
216 
217 /*
218  * Opal message notifier based on message type. Allow subscribers to get
219  * notified for specific messgae type.
220  */
opal_message_notifier_register(enum opal_msg_type msg_type,struct notifier_block * nb)221 int opal_message_notifier_register(enum opal_msg_type msg_type,
222 					struct notifier_block *nb)
223 {
224 	if (!nb || msg_type >= OPAL_MSG_TYPE_MAX) {
225 		pr_warning("%s: Invalid arguments, msg_type:%d\n",
226 			   __func__, msg_type);
227 		return -EINVAL;
228 	}
229 
230 	return atomic_notifier_chain_register(
231 				&opal_msg_notifier_head[msg_type], nb);
232 }
233 EXPORT_SYMBOL_GPL(opal_message_notifier_register);
234 
opal_message_notifier_unregister(enum opal_msg_type msg_type,struct notifier_block * nb)235 int opal_message_notifier_unregister(enum opal_msg_type msg_type,
236 				     struct notifier_block *nb)
237 {
238 	return atomic_notifier_chain_unregister(
239 			&opal_msg_notifier_head[msg_type], nb);
240 }
241 EXPORT_SYMBOL_GPL(opal_message_notifier_unregister);
242 
opal_message_do_notify(uint32_t msg_type,void * msg)243 static void opal_message_do_notify(uint32_t msg_type, void *msg)
244 {
245 	/* notify subscribers */
246 	atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
247 					msg_type, msg);
248 }
249 
opal_handle_message(void)250 static void opal_handle_message(void)
251 {
252 	s64 ret;
253 	/*
254 	 * TODO: pre-allocate a message buffer depending on opal-msg-size
255 	 * value in /proc/device-tree.
256 	 */
257 	static struct opal_msg msg;
258 	u32 type;
259 
260 	ret = opal_get_msg(__pa(&msg), sizeof(msg));
261 	/* No opal message pending. */
262 	if (ret == OPAL_RESOURCE)
263 		return;
264 
265 	/* check for errors. */
266 	if (ret) {
267 		pr_warning("%s: Failed to retrieve opal message, err=%lld\n",
268 				__func__, ret);
269 		return;
270 	}
271 
272 	type = be32_to_cpu(msg.msg_type);
273 
274 	/* Sanity check */
275 	if (type >= OPAL_MSG_TYPE_MAX) {
276 		pr_warn_once("%s: Unknown message type: %u\n", __func__, type);
277 		return;
278 	}
279 	opal_message_do_notify(type, (void *)&msg);
280 }
281 
opal_message_notify(int irq,void * data)282 static irqreturn_t opal_message_notify(int irq, void *data)
283 {
284 	opal_handle_message();
285 	return IRQ_HANDLED;
286 }
287 
opal_message_init(void)288 static int __init opal_message_init(void)
289 {
290 	int ret, i, irq;
291 
292 	for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
293 		ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
294 
295 	irq = opal_event_request(ilog2(OPAL_EVENT_MSG_PENDING));
296 	if (!irq) {
297 		pr_err("%s: Can't register OPAL event irq (%d)\n",
298 		       __func__, irq);
299 		return irq;
300 	}
301 
302 	ret = request_irq(irq, opal_message_notify,
303 			IRQ_TYPE_LEVEL_HIGH, "opal-msg", NULL);
304 	if (ret) {
305 		pr_err("%s: Can't request OPAL event irq (%d)\n",
306 		       __func__, ret);
307 		return ret;
308 	}
309 
310 	return 0;
311 }
312 
opal_get_chars(uint32_t vtermno,char * buf,int count)313 int opal_get_chars(uint32_t vtermno, char *buf, int count)
314 {
315 	s64 rc;
316 	__be64 evt, len;
317 
318 	if (!opal.entry)
319 		return -ENODEV;
320 	opal_poll_events(&evt);
321 	if ((be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_INPUT) == 0)
322 		return 0;
323 	len = cpu_to_be64(count);
324 	rc = opal_console_read(vtermno, &len, buf);
325 	if (rc == OPAL_SUCCESS)
326 		return be64_to_cpu(len);
327 	return 0;
328 }
329 
opal_put_chars(uint32_t vtermno,const char * data,int total_len)330 int opal_put_chars(uint32_t vtermno, const char *data, int total_len)
331 {
332 	int written = 0;
333 	__be64 olen;
334 	s64 len, rc;
335 	unsigned long flags;
336 	__be64 evt;
337 
338 	if (!opal.entry)
339 		return -ENODEV;
340 
341 	/* We want put_chars to be atomic to avoid mangling of hvsi
342 	 * packets. To do that, we first test for room and return
343 	 * -EAGAIN if there isn't enough.
344 	 *
345 	 * Unfortunately, opal_console_write_buffer_space() doesn't
346 	 * appear to work on opal v1, so we just assume there is
347 	 * enough room and be done with it
348 	 */
349 	spin_lock_irqsave(&opal_write_lock, flags);
350 	rc = opal_console_write_buffer_space(vtermno, &olen);
351 	len = be64_to_cpu(olen);
352 	if (rc || len < total_len) {
353 		spin_unlock_irqrestore(&opal_write_lock, flags);
354 		/* Closed -> drop characters */
355 		if (rc)
356 			return total_len;
357 		opal_poll_events(NULL);
358 		return -EAGAIN;
359 	}
360 
361 	/* We still try to handle partial completions, though they
362 	 * should no longer happen.
363 	 */
364 	rc = OPAL_BUSY;
365 	while(total_len > 0 && (rc == OPAL_BUSY ||
366 				rc == OPAL_BUSY_EVENT || rc == OPAL_SUCCESS)) {
367 		olen = cpu_to_be64(total_len);
368 		rc = opal_console_write(vtermno, &olen, data);
369 		len = be64_to_cpu(olen);
370 
371 		/* Closed or other error drop */
372 		if (rc != OPAL_SUCCESS && rc != OPAL_BUSY &&
373 		    rc != OPAL_BUSY_EVENT) {
374 			written += total_len;
375 			break;
376 		}
377 		if (rc == OPAL_SUCCESS) {
378 			total_len -= len;
379 			data += len;
380 			written += len;
381 		}
382 		/* This is a bit nasty but we need that for the console to
383 		 * flush when there aren't any interrupts. We will clean
384 		 * things a bit later to limit that to synchronous path
385 		 * such as the kernel console and xmon/udbg
386 		 */
387 		do
388 			opal_poll_events(&evt);
389 		while(rc == OPAL_SUCCESS &&
390 			(be64_to_cpu(evt) & OPAL_EVENT_CONSOLE_OUTPUT));
391 	}
392 	spin_unlock_irqrestore(&opal_write_lock, flags);
393 	return written;
394 }
395 
opal_recover_mce(struct pt_regs * regs,struct machine_check_event * evt)396 static int opal_recover_mce(struct pt_regs *regs,
397 					struct machine_check_event *evt)
398 {
399 	int recovered = 0;
400 	uint64_t ea = get_mce_fault_addr(evt);
401 
402 	if (!(regs->msr & MSR_RI)) {
403 		/* If MSR_RI isn't set, we cannot recover */
404 		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
405 		recovered = 0;
406 	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
407 		/* Platform corrected itself */
408 		recovered = 1;
409 	} else if (ea && !is_kernel_addr(ea)) {
410 		/*
411 		 * Faulting address is not in kernel text. We should be fine.
412 		 * We need to find which process uses this address.
413 		 * For now, kill the task if we have received exception when
414 		 * in userspace.
415 		 *
416 		 * TODO: Queue up this address for hwpoisioning later.
417 		 */
418 		if (user_mode(regs) && !is_global_init(current)) {
419 			_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
420 			recovered = 1;
421 		} else
422 			recovered = 0;
423 	} else if (user_mode(regs) && !is_global_init(current) &&
424 		evt->severity == MCE_SEV_ERROR_SYNC) {
425 		/*
426 		 * If we have received a synchronous error when in userspace
427 		 * kill the task.
428 		 */
429 		_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
430 		recovered = 1;
431 	}
432 	return recovered;
433 }
434 
opal_machine_check(struct pt_regs * regs)435 int opal_machine_check(struct pt_regs *regs)
436 {
437 	struct machine_check_event evt;
438 	int ret;
439 
440 	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
441 		return 0;
442 
443 	/* Print things out */
444 	if (evt.version != MCE_V1) {
445 		pr_err("Machine Check Exception, Unknown event version %d !\n",
446 		       evt.version);
447 		return 0;
448 	}
449 	machine_check_print_event_info(&evt);
450 
451 	if (opal_recover_mce(regs, &evt))
452 		return 1;
453 
454 	/*
455 	 * Unrecovered machine check, we are heading to panic path.
456 	 *
457 	 * We may have hit this MCE in very early stage of kernel
458 	 * initialization even before opal-prd has started running. If
459 	 * this is the case then this MCE error may go un-noticed or
460 	 * un-analyzed if we go down panic path. We need to inform
461 	 * BMC/OCC about this error so that they can collect relevant
462 	 * data for error analysis before rebooting.
463 	 * Use opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR) to do so.
464 	 * This function may not return on BMC based system.
465 	 */
466 	ret = opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR,
467 			"Unrecoverable Machine Check exception");
468 	if (ret == OPAL_UNSUPPORTED) {
469 		pr_emerg("Reboot type %d not supported\n",
470 					OPAL_REBOOT_PLATFORM_ERROR);
471 	}
472 
473 	/*
474 	 * We reached here. There can be three possibilities:
475 	 * 1. We are running on a firmware level that do not support
476 	 *    opal_cec_reboot2()
477 	 * 2. We are running on a firmware level that do not support
478 	 *    OPAL_REBOOT_PLATFORM_ERROR reboot type.
479 	 * 3. We are running on FSP based system that does not need opal
480 	 *    to trigger checkstop explicitly for error analysis. The FSP
481 	 *    PRD component would have already got notified about this
482 	 *    error through other channels.
483 	 *
484 	 * If hardware marked this as an unrecoverable MCE, we are
485 	 * going to panic anyway. Even if it didn't, it's not safe to
486 	 * continue at this point, so we should explicitly panic.
487 	 */
488 
489 	panic("PowerNV Unrecovered Machine Check");
490 	return 0;
491 }
492 
493 /* Early hmi handler called in real mode. */
opal_hmi_exception_early(struct pt_regs * regs)494 int opal_hmi_exception_early(struct pt_regs *regs)
495 {
496 	s64 rc;
497 
498 	/*
499 	 * call opal hmi handler. Pass paca address as token.
500 	 * The return value OPAL_SUCCESS is an indication that there is
501 	 * an HMI event generated waiting to pull by Linux.
502 	 */
503 	rc = opal_handle_hmi();
504 	if (rc == OPAL_SUCCESS) {
505 		local_paca->hmi_event_available = 1;
506 		return 1;
507 	}
508 	return 0;
509 }
510 
511 /* HMI exception handler called in virtual mode during check_irq_replay. */
opal_handle_hmi_exception(struct pt_regs * regs)512 int opal_handle_hmi_exception(struct pt_regs *regs)
513 {
514 	s64 rc;
515 	__be64 evt = 0;
516 
517 	/*
518 	 * Check if HMI event is available.
519 	 * if Yes, then call opal_poll_events to pull opal messages and
520 	 * process them.
521 	 */
522 	if (!local_paca->hmi_event_available)
523 		return 0;
524 
525 	local_paca->hmi_event_available = 0;
526 	rc = opal_poll_events(&evt);
527 	if (rc == OPAL_SUCCESS && evt)
528 		opal_handle_events(be64_to_cpu(evt));
529 
530 	return 1;
531 }
532 
find_recovery_address(uint64_t nip)533 static uint64_t find_recovery_address(uint64_t nip)
534 {
535 	int i;
536 
537 	for (i = 0; i < mc_recoverable_range_len; i++)
538 		if ((nip >= mc_recoverable_range[i].start_addr) &&
539 		    (nip < mc_recoverable_range[i].end_addr))
540 		    return mc_recoverable_range[i].recover_addr;
541 	return 0;
542 }
543 
opal_mce_check_early_recovery(struct pt_regs * regs)544 bool opal_mce_check_early_recovery(struct pt_regs *regs)
545 {
546 	uint64_t recover_addr = 0;
547 
548 	if (!opal.base || !opal.size)
549 		goto out;
550 
551 	if ((regs->nip >= opal.base) &&
552 			(regs->nip <= (opal.base + opal.size)))
553 		recover_addr = find_recovery_address(regs->nip);
554 
555 	/*
556 	 * Setup regs->nip to rfi into fixup address.
557 	 */
558 	if (recover_addr)
559 		regs->nip = recover_addr;
560 
561 out:
562 	return !!recover_addr;
563 }
564 
opal_sysfs_init(void)565 static int opal_sysfs_init(void)
566 {
567 	opal_kobj = kobject_create_and_add("opal", firmware_kobj);
568 	if (!opal_kobj) {
569 		pr_warn("kobject_create_and_add opal failed\n");
570 		return -ENOMEM;
571 	}
572 
573 	return 0;
574 }
575 
symbol_map_read(struct file * fp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)576 static ssize_t symbol_map_read(struct file *fp, struct kobject *kobj,
577 			       struct bin_attribute *bin_attr,
578 			       char *buf, loff_t off, size_t count)
579 {
580 	return memory_read_from_buffer(buf, count, &off, bin_attr->private,
581 				       bin_attr->size);
582 }
583 
584 static struct bin_attribute symbol_map_attr = {
585 	.attr = {.name = "symbol_map", .mode = 0400},
586 	.read = symbol_map_read
587 };
588 
opal_export_symmap(void)589 static void opal_export_symmap(void)
590 {
591 	const __be64 *syms;
592 	unsigned int size;
593 	struct device_node *fw;
594 	int rc;
595 
596 	fw = of_find_node_by_path("/ibm,opal/firmware");
597 	if (!fw)
598 		return;
599 	syms = of_get_property(fw, "symbol-map", &size);
600 	if (!syms || size != 2 * sizeof(__be64))
601 		return;
602 
603 	/* Setup attributes */
604 	symbol_map_attr.private = __va(be64_to_cpu(syms[0]));
605 	symbol_map_attr.size = be64_to_cpu(syms[1]);
606 
607 	rc = sysfs_create_bin_file(opal_kobj, &symbol_map_attr);
608 	if (rc)
609 		pr_warn("Error %d creating OPAL symbols file\n", rc);
610 }
611 
opal_dump_region_init(void)612 static void __init opal_dump_region_init(void)
613 {
614 	void *addr;
615 	uint64_t size;
616 	int rc;
617 
618 	if (!opal_check_token(OPAL_REGISTER_DUMP_REGION))
619 		return;
620 
621 	/* Register kernel log buffer */
622 	addr = log_buf_addr_get();
623 	if (addr == NULL)
624 		return;
625 
626 	size = log_buf_len_get();
627 	if (size == 0)
628 		return;
629 
630 	rc = opal_register_dump_region(OPAL_DUMP_REGION_LOG_BUF,
631 				       __pa(addr), size);
632 	/* Don't warn if this is just an older OPAL that doesn't
633 	 * know about that call
634 	 */
635 	if (rc && rc != OPAL_UNSUPPORTED)
636 		pr_warn("DUMP: Failed to register kernel log buffer. "
637 			"rc = %d\n", rc);
638 }
639 
opal_pdev_init(struct device_node * opal_node,const char * compatible)640 static void opal_pdev_init(struct device_node *opal_node,
641 		const char *compatible)
642 {
643 	struct device_node *np;
644 
645 	for_each_child_of_node(opal_node, np)
646 		if (of_device_is_compatible(np, compatible))
647 			of_platform_device_create(np, NULL, NULL);
648 }
649 
opal_i2c_create_devs(void)650 static void opal_i2c_create_devs(void)
651 {
652 	struct device_node *np;
653 
654 	for_each_compatible_node(np, NULL, "ibm,opal-i2c")
655 		of_platform_device_create(np, NULL, NULL);
656 }
657 
kopald(void * unused)658 static int kopald(void *unused)
659 {
660 	__be64 events;
661 
662 	set_freezable();
663 	do {
664 		try_to_freeze();
665 		opal_poll_events(&events);
666 		opal_handle_events(be64_to_cpu(events));
667 		msleep_interruptible(opal_heartbeat);
668 	} while (!kthread_should_stop());
669 
670 	return 0;
671 }
672 
opal_init_heartbeat(void)673 static void opal_init_heartbeat(void)
674 {
675 	/* Old firwmware, we assume the HVC heartbeat is sufficient */
676 	if (of_property_read_u32(opal_node, "ibm,heartbeat-ms",
677 				 &opal_heartbeat) != 0)
678 		opal_heartbeat = 0;
679 
680 	if (opal_heartbeat)
681 		kthread_run(kopald, NULL, "kopald");
682 }
683 
opal_init(void)684 static int __init opal_init(void)
685 {
686 	struct device_node *np, *consoles, *leds;
687 	int rc;
688 
689 	opal_node = of_find_node_by_path("/ibm,opal");
690 	if (!opal_node) {
691 		pr_warn("Device node not found\n");
692 		return -ENODEV;
693 	}
694 
695 	/* Register OPAL consoles if any ports */
696 	consoles = of_find_node_by_path("/ibm,opal/consoles");
697 	if (consoles) {
698 		for_each_child_of_node(consoles, np) {
699 			if (strcmp(np->name, "serial"))
700 				continue;
701 			of_platform_device_create(np, NULL, NULL);
702 		}
703 		of_node_put(consoles);
704 	}
705 
706 	/* Initialise OPAL messaging system */
707 	opal_message_init();
708 
709 	/* Initialise OPAL asynchronous completion interface */
710 	opal_async_comp_init();
711 
712 	/* Initialise OPAL sensor interface */
713 	opal_sensor_init();
714 
715 	/* Initialise OPAL hypervisor maintainence interrupt handling */
716 	opal_hmi_handler_init();
717 
718 	/* Create i2c platform devices */
719 	opal_i2c_create_devs();
720 
721 	/* Setup a heatbeat thread if requested by OPAL */
722 	opal_init_heartbeat();
723 
724 	/* Create leds platform devices */
725 	leds = of_find_node_by_path("/ibm,opal/leds");
726 	if (leds) {
727 		of_platform_device_create(leds, "opal_leds", NULL);
728 		of_node_put(leds);
729 	}
730 
731 	/* Create "opal" kobject under /sys/firmware */
732 	rc = opal_sysfs_init();
733 	if (rc == 0) {
734 		/* Export symbol map to userspace */
735 		opal_export_symmap();
736 		/* Setup dump region interface */
737 		opal_dump_region_init();
738 		/* Setup error log interface */
739 		rc = opal_elog_init();
740 		/* Setup code update interface */
741 		opal_flash_update_init();
742 		/* Setup platform dump extract interface */
743 		opal_platform_dump_init();
744 		/* Setup system parameters interface */
745 		opal_sys_param_init();
746 		/* Setup message log interface. */
747 		opal_msglog_init();
748 	}
749 
750 	/* Initialize platform devices: IPMI backend, PRD & flash interface */
751 	opal_pdev_init(opal_node, "ibm,opal-ipmi");
752 	opal_pdev_init(opal_node, "ibm,opal-flash");
753 	opal_pdev_init(opal_node, "ibm,opal-prd");
754 
755 	/* Initialise OPAL kmsg dumper for flushing console on panic */
756 	opal_kmsg_init();
757 
758 	return 0;
759 }
760 machine_subsys_initcall(powernv, opal_init);
761 
opal_shutdown(void)762 void opal_shutdown(void)
763 {
764 	long rc = OPAL_BUSY;
765 
766 	opal_event_shutdown();
767 
768 	/*
769 	 * Then sync with OPAL which ensure anything that can
770 	 * potentially write to our memory has completed such
771 	 * as an ongoing dump retrieval
772 	 */
773 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
774 		rc = opal_sync_host_reboot();
775 		if (rc == OPAL_BUSY)
776 			opal_poll_events(NULL);
777 		else
778 			mdelay(10);
779 	}
780 
781 	/* Unregister memory dump region */
782 	if (opal_check_token(OPAL_UNREGISTER_DUMP_REGION))
783 		opal_unregister_dump_region(OPAL_DUMP_REGION_LOG_BUF);
784 }
785 
786 /* Export this so that test modules can use it */
787 EXPORT_SYMBOL_GPL(opal_invalid_call);
788 EXPORT_SYMBOL_GPL(opal_xscom_read);
789 EXPORT_SYMBOL_GPL(opal_xscom_write);
790 EXPORT_SYMBOL_GPL(opal_ipmi_send);
791 EXPORT_SYMBOL_GPL(opal_ipmi_recv);
792 EXPORT_SYMBOL_GPL(opal_flash_read);
793 EXPORT_SYMBOL_GPL(opal_flash_write);
794 EXPORT_SYMBOL_GPL(opal_flash_erase);
795 EXPORT_SYMBOL_GPL(opal_prd_msg);
796 
797 /* Convert a region of vmalloc memory to an opal sg list */
opal_vmalloc_to_sg_list(void * vmalloc_addr,unsigned long vmalloc_size)798 struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
799 					     unsigned long vmalloc_size)
800 {
801 	struct opal_sg_list *sg, *first = NULL;
802 	unsigned long i = 0;
803 
804 	sg = kzalloc(PAGE_SIZE, GFP_KERNEL);
805 	if (!sg)
806 		goto nomem;
807 
808 	first = sg;
809 
810 	while (vmalloc_size > 0) {
811 		uint64_t data = vmalloc_to_pfn(vmalloc_addr) << PAGE_SHIFT;
812 		uint64_t length = min(vmalloc_size, PAGE_SIZE);
813 
814 		sg->entry[i].data = cpu_to_be64(data);
815 		sg->entry[i].length = cpu_to_be64(length);
816 		i++;
817 
818 		if (i >= SG_ENTRIES_PER_NODE) {
819 			struct opal_sg_list *next;
820 
821 			next = kzalloc(PAGE_SIZE, GFP_KERNEL);
822 			if (!next)
823 				goto nomem;
824 
825 			sg->length = cpu_to_be64(
826 					i * sizeof(struct opal_sg_entry) + 16);
827 			i = 0;
828 			sg->next = cpu_to_be64(__pa(next));
829 			sg = next;
830 		}
831 
832 		vmalloc_addr += length;
833 		vmalloc_size -= length;
834 	}
835 
836 	sg->length = cpu_to_be64(i * sizeof(struct opal_sg_entry) + 16);
837 
838 	return first;
839 
840 nomem:
841 	pr_err("%s : Failed to allocate memory\n", __func__);
842 	opal_free_sg_list(first);
843 	return NULL;
844 }
845 
opal_free_sg_list(struct opal_sg_list * sg)846 void opal_free_sg_list(struct opal_sg_list *sg)
847 {
848 	while (sg) {
849 		uint64_t next = be64_to_cpu(sg->next);
850 
851 		kfree(sg);
852 
853 		if (next)
854 			sg = __va(next);
855 		else
856 			sg = NULL;
857 	}
858 }
859 
opal_error_code(int rc)860 int opal_error_code(int rc)
861 {
862 	switch (rc) {
863 	case OPAL_SUCCESS:		return 0;
864 
865 	case OPAL_PARAMETER:		return -EINVAL;
866 	case OPAL_ASYNC_COMPLETION:	return -EINPROGRESS;
867 	case OPAL_BUSY_EVENT:		return -EBUSY;
868 	case OPAL_NO_MEM:		return -ENOMEM;
869 	case OPAL_PERMISSION:		return -EPERM;
870 
871 	case OPAL_UNSUPPORTED:		return -EIO;
872 	case OPAL_HARDWARE:		return -EIO;
873 	case OPAL_INTERNAL_ERROR:	return -EIO;
874 	default:
875 		pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
876 		return -EIO;
877 	}
878 }
879 
880 EXPORT_SYMBOL_GPL(opal_poll_events);
881 EXPORT_SYMBOL_GPL(opal_rtc_read);
882 EXPORT_SYMBOL_GPL(opal_rtc_write);
883 EXPORT_SYMBOL_GPL(opal_tpo_read);
884 EXPORT_SYMBOL_GPL(opal_tpo_write);
885 EXPORT_SYMBOL_GPL(opal_i2c_request);
886 /* Export these symbols for PowerNV LED class driver */
887 EXPORT_SYMBOL_GPL(opal_leds_get_ind);
888 EXPORT_SYMBOL_GPL(opal_leds_set_ind);
889