1/*
2 *
3 * Procedures for interfacing to the RTAS on CHRP machines.
4 *
5 * Peter Bergner, IBM	March 2001.
6 * Copyright (C) 2001 IBM.
7 *
8 *      This program is free software; you can redistribute it and/or
9 *      modify it under the terms of the GNU General Public License
10 *      as published by the Free Software Foundation; either version
11 *      2 of the License, or (at your option) any later version.
12 */
13
14#include <stdarg.h>
15#include <linux/kernel.h>
16#include <linux/types.h>
17#include <linux/spinlock.h>
18#include <linux/export.h>
19#include <linux/init.h>
20#include <linux/capability.h>
21#include <linux/delay.h>
22#include <linux/cpu.h>
23#include <linux/smp.h>
24#include <linux/completion.h>
25#include <linux/cpumask.h>
26#include <linux/memblock.h>
27#include <linux/slab.h>
28#include <linux/reboot.h>
29
30#include <asm/prom.h>
31#include <asm/rtas.h>
32#include <asm/hvcall.h>
33#include <asm/machdep.h>
34#include <asm/firmware.h>
35#include <asm/page.h>
36#include <asm/param.h>
37#include <asm/delay.h>
38#include <asm/uaccess.h>
39#include <asm/udbg.h>
40#include <asm/syscalls.h>
41#include <asm/smp.h>
42#include <linux/atomic.h>
43#include <asm/time.h>
44#include <asm/mmu.h>
45#include <asm/topology.h>
46
47struct rtas_t rtas = {
48	.lock = __ARCH_SPIN_LOCK_UNLOCKED
49};
50EXPORT_SYMBOL(rtas);
51
52DEFINE_SPINLOCK(rtas_data_buf_lock);
53EXPORT_SYMBOL(rtas_data_buf_lock);
54
55char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
56EXPORT_SYMBOL(rtas_data_buf);
57
58unsigned long rtas_rmo_buf;
59
60/*
61 * If non-NULL, this gets called when the kernel terminates.
62 * This is done like this so rtas_flash can be a module.
63 */
64void (*rtas_flash_term_hook)(int);
65EXPORT_SYMBOL(rtas_flash_term_hook);
66
67/* RTAS use home made raw locking instead of spin_lock_irqsave
68 * because those can be called from within really nasty contexts
69 * such as having the timebase stopped which would lockup with
70 * normal locks and spinlock debugging enabled
71 */
72static unsigned long lock_rtas(void)
73{
74	unsigned long flags;
75
76	local_irq_save(flags);
77	preempt_disable();
78	arch_spin_lock_flags(&rtas.lock, flags);
79	return flags;
80}
81
82static void unlock_rtas(unsigned long flags)
83{
84	arch_spin_unlock(&rtas.lock);
85	local_irq_restore(flags);
86	preempt_enable();
87}
88
89/*
90 * call_rtas_display_status and call_rtas_display_status_delay
91 * are designed only for very early low-level debugging, which
92 * is why the token is hard-coded to 10.
93 */
94static void call_rtas_display_status(unsigned char c)
95{
96	struct rtas_args *args = &rtas.args;
97	unsigned long s;
98
99	if (!rtas.base)
100		return;
101	s = lock_rtas();
102
103	args->token = cpu_to_be32(10);
104	args->nargs = cpu_to_be32(1);
105	args->nret  = cpu_to_be32(1);
106	args->rets  = &(args->args[1]);
107	args->args[0] = cpu_to_be32(c);
108
109	enter_rtas(__pa(args));
110
111	unlock_rtas(s);
112}
113
114static void call_rtas_display_status_delay(char c)
115{
116	static int pending_newline = 0;  /* did last write end with unprinted newline? */
117	static int width = 16;
118
119	if (c == '\n') {
120		while (width-- > 0)
121			call_rtas_display_status(' ');
122		width = 16;
123		mdelay(500);
124		pending_newline = 1;
125	} else {
126		if (pending_newline) {
127			call_rtas_display_status('\r');
128			call_rtas_display_status('\n');
129		}
130		pending_newline = 0;
131		if (width--) {
132			call_rtas_display_status(c);
133			udelay(10000);
134		}
135	}
136}
137
138void __init udbg_init_rtas_panel(void)
139{
140	udbg_putc = call_rtas_display_status_delay;
141}
142
143#ifdef CONFIG_UDBG_RTAS_CONSOLE
144
145/* If you think you're dying before early_init_dt_scan_rtas() does its
146 * work, you can hard code the token values for your firmware here and
147 * hardcode rtas.base/entry etc.
148 */
149static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
150static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
151
152static void udbg_rtascon_putc(char c)
153{
154	int tries;
155
156	if (!rtas.base)
157		return;
158
159	/* Add CRs before LFs */
160	if (c == '\n')
161		udbg_rtascon_putc('\r');
162
163	/* if there is more than one character to be displayed, wait a bit */
164	for (tries = 0; tries < 16; tries++) {
165		if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
166			break;
167		udelay(1000);
168	}
169}
170
171static int udbg_rtascon_getc_poll(void)
172{
173	int c;
174
175	if (!rtas.base)
176		return -1;
177
178	if (rtas_call(rtas_getchar_token, 0, 2, &c))
179		return -1;
180
181	return c;
182}
183
184static int udbg_rtascon_getc(void)
185{
186	int c;
187
188	while ((c = udbg_rtascon_getc_poll()) == -1)
189		;
190
191	return c;
192}
193
194
195void __init udbg_init_rtas_console(void)
196{
197	udbg_putc = udbg_rtascon_putc;
198	udbg_getc = udbg_rtascon_getc;
199	udbg_getc_poll = udbg_rtascon_getc_poll;
200}
201#endif /* CONFIG_UDBG_RTAS_CONSOLE */
202
203void rtas_progress(char *s, unsigned short hex)
204{
205	struct device_node *root;
206	int width;
207	const __be32 *p;
208	char *os;
209	static int display_character, set_indicator;
210	static int display_width, display_lines, form_feed;
211	static const int *row_width;
212	static DEFINE_SPINLOCK(progress_lock);
213	static int current_line;
214	static int pending_newline = 0;  /* did last write end with unprinted newline? */
215
216	if (!rtas.base)
217		return;
218
219	if (display_width == 0) {
220		display_width = 0x10;
221		if ((root = of_find_node_by_path("/rtas"))) {
222			if ((p = of_get_property(root,
223					"ibm,display-line-length", NULL)))
224				display_width = be32_to_cpu(*p);
225			if ((p = of_get_property(root,
226					"ibm,form-feed", NULL)))
227				form_feed = be32_to_cpu(*p);
228			if ((p = of_get_property(root,
229					"ibm,display-number-of-lines", NULL)))
230				display_lines = be32_to_cpu(*p);
231			row_width = of_get_property(root,
232					"ibm,display-truncation-length", NULL);
233			of_node_put(root);
234		}
235		display_character = rtas_token("display-character");
236		set_indicator = rtas_token("set-indicator");
237	}
238
239	if (display_character == RTAS_UNKNOWN_SERVICE) {
240		/* use hex display if available */
241		if (set_indicator != RTAS_UNKNOWN_SERVICE)
242			rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
243		return;
244	}
245
246	spin_lock(&progress_lock);
247
248	/*
249	 * Last write ended with newline, but we didn't print it since
250	 * it would just clear the bottom line of output. Print it now
251	 * instead.
252	 *
253	 * If no newline is pending and form feed is supported, clear the
254	 * display with a form feed; otherwise, print a CR to start output
255	 * at the beginning of the line.
256	 */
257	if (pending_newline) {
258		rtas_call(display_character, 1, 1, NULL, '\r');
259		rtas_call(display_character, 1, 1, NULL, '\n');
260		pending_newline = 0;
261	} else {
262		current_line = 0;
263		if (form_feed)
264			rtas_call(display_character, 1, 1, NULL,
265				  (char)form_feed);
266		else
267			rtas_call(display_character, 1, 1, NULL, '\r');
268	}
269
270	if (row_width)
271		width = row_width[current_line];
272	else
273		width = display_width;
274	os = s;
275	while (*os) {
276		if (*os == '\n' || *os == '\r') {
277			/* If newline is the last character, save it
278			 * until next call to avoid bumping up the
279			 * display output.
280			 */
281			if (*os == '\n' && !os[1]) {
282				pending_newline = 1;
283				current_line++;
284				if (current_line > display_lines-1)
285					current_line = display_lines-1;
286				spin_unlock(&progress_lock);
287				return;
288			}
289
290			/* RTAS wants CR-LF, not just LF */
291
292			if (*os == '\n') {
293				rtas_call(display_character, 1, 1, NULL, '\r');
294				rtas_call(display_character, 1, 1, NULL, '\n');
295			} else {
296				/* CR might be used to re-draw a line, so we'll
297				 * leave it alone and not add LF.
298				 */
299				rtas_call(display_character, 1, 1, NULL, *os);
300			}
301
302			if (row_width)
303				width = row_width[current_line];
304			else
305				width = display_width;
306		} else {
307			width--;
308			rtas_call(display_character, 1, 1, NULL, *os);
309		}
310
311		os++;
312
313		/* if we overwrite the screen length */
314		if (width <= 0)
315			while ((*os != 0) && (*os != '\n') && (*os != '\r'))
316				os++;
317	}
318
319	spin_unlock(&progress_lock);
320}
321EXPORT_SYMBOL(rtas_progress);		/* needed by rtas_flash module */
322
323int rtas_token(const char *service)
324{
325	const __be32 *tokp;
326	if (rtas.dev == NULL)
327		return RTAS_UNKNOWN_SERVICE;
328	tokp = of_get_property(rtas.dev, service, NULL);
329	return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
330}
331EXPORT_SYMBOL(rtas_token);
332
333int rtas_service_present(const char *service)
334{
335	return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
336}
337EXPORT_SYMBOL(rtas_service_present);
338
339#ifdef CONFIG_RTAS_ERROR_LOGGING
340/*
341 * Return the firmware-specified size of the error log buffer
342 *  for all rtas calls that require an error buffer argument.
343 *  This includes 'check-exception' and 'rtas-last-error'.
344 */
345int rtas_get_error_log_max(void)
346{
347	static int rtas_error_log_max;
348	if (rtas_error_log_max)
349		return rtas_error_log_max;
350
351	rtas_error_log_max = rtas_token ("rtas-error-log-max");
352	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
353	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
354		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
355			rtas_error_log_max);
356		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
357	}
358	return rtas_error_log_max;
359}
360EXPORT_SYMBOL(rtas_get_error_log_max);
361
362
363static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
364static int rtas_last_error_token;
365
366/** Return a copy of the detailed error text associated with the
367 *  most recent failed call to rtas.  Because the error text
368 *  might go stale if there are any other intervening rtas calls,
369 *  this routine must be called atomically with whatever produced
370 *  the error (i.e. with rtas.lock still held from the previous call).
371 */
372static char *__fetch_rtas_last_error(char *altbuf)
373{
374	struct rtas_args err_args, save_args;
375	u32 bufsz;
376	char *buf = NULL;
377
378	if (rtas_last_error_token == -1)
379		return NULL;
380
381	bufsz = rtas_get_error_log_max();
382
383	err_args.token = cpu_to_be32(rtas_last_error_token);
384	err_args.nargs = cpu_to_be32(2);
385	err_args.nret = cpu_to_be32(1);
386	err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
387	err_args.args[1] = cpu_to_be32(bufsz);
388	err_args.args[2] = 0;
389
390	save_args = rtas.args;
391	rtas.args = err_args;
392
393	enter_rtas(__pa(&rtas.args));
394
395	err_args = rtas.args;
396	rtas.args = save_args;
397
398	/* Log the error in the unlikely case that there was one. */
399	if (unlikely(err_args.args[2] == 0)) {
400		if (altbuf) {
401			buf = altbuf;
402		} else {
403			buf = rtas_err_buf;
404			if (slab_is_available())
405				buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
406		}
407		if (buf)
408			memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
409	}
410
411	return buf;
412}
413
414#define get_errorlog_buffer()	kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
415
416#else /* CONFIG_RTAS_ERROR_LOGGING */
417#define __fetch_rtas_last_error(x)	NULL
418#define get_errorlog_buffer()		NULL
419#endif
420
421int rtas_call(int token, int nargs, int nret, int *outputs, ...)
422{
423	va_list list;
424	int i;
425	unsigned long s;
426	struct rtas_args *rtas_args;
427	char *buff_copy = NULL;
428	int ret;
429
430	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
431		return -1;
432
433	s = lock_rtas();
434	rtas_args = &rtas.args;
435
436	rtas_args->token = cpu_to_be32(token);
437	rtas_args->nargs = cpu_to_be32(nargs);
438	rtas_args->nret  = cpu_to_be32(nret);
439	rtas_args->rets  = &(rtas_args->args[nargs]);
440	va_start(list, outputs);
441	for (i = 0; i < nargs; ++i)
442		rtas_args->args[i] = cpu_to_be32(va_arg(list, __u32));
443	va_end(list);
444
445	for (i = 0; i < nret; ++i)
446		rtas_args->rets[i] = 0;
447
448	enter_rtas(__pa(rtas_args));
449
450	/* A -1 return code indicates that the last command couldn't
451	   be completed due to a hardware error. */
452	if (be32_to_cpu(rtas_args->rets[0]) == -1)
453		buff_copy = __fetch_rtas_last_error(NULL);
454
455	if (nret > 1 && outputs != NULL)
456		for (i = 0; i < nret-1; ++i)
457			outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
458	ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
459
460	unlock_rtas(s);
461
462	if (buff_copy) {
463		log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
464		if (slab_is_available())
465			kfree(buff_copy);
466	}
467	return ret;
468}
469EXPORT_SYMBOL(rtas_call);
470
471/* For RTAS_BUSY (-2), delay for 1 millisecond.  For an extended busy status
472 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
473 */
474unsigned int rtas_busy_delay_time(int status)
475{
476	int order;
477	unsigned int ms = 0;
478
479	if (status == RTAS_BUSY) {
480		ms = 1;
481	} else if (status >= 9900 && status <= 9905) {
482		order = status - 9900;
483		for (ms = 1; order > 0; order--)
484			ms *= 10;
485	}
486
487	return ms;
488}
489EXPORT_SYMBOL(rtas_busy_delay_time);
490
491/* For an RTAS busy status code, perform the hinted delay. */
492unsigned int rtas_busy_delay(int status)
493{
494	unsigned int ms;
495
496	might_sleep();
497	ms = rtas_busy_delay_time(status);
498	if (ms && need_resched())
499		msleep(ms);
500
501	return ms;
502}
503EXPORT_SYMBOL(rtas_busy_delay);
504
505static int rtas_error_rc(int rtas_rc)
506{
507	int rc;
508
509	switch (rtas_rc) {
510		case -1: 		/* Hardware Error */
511			rc = -EIO;
512			break;
513		case -3:		/* Bad indicator/domain/etc */
514			rc = -EINVAL;
515			break;
516		case -9000:		/* Isolation error */
517			rc = -EFAULT;
518			break;
519		case -9001:		/* Outstanding TCE/PTE */
520			rc = -EEXIST;
521			break;
522		case -9002:		/* No usable slot */
523			rc = -ENODEV;
524			break;
525		default:
526			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
527					__func__, rtas_rc);
528			rc = -ERANGE;
529			break;
530	}
531	return rc;
532}
533
534int rtas_get_power_level(int powerdomain, int *level)
535{
536	int token = rtas_token("get-power-level");
537	int rc;
538
539	if (token == RTAS_UNKNOWN_SERVICE)
540		return -ENOENT;
541
542	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
543		udelay(1);
544
545	if (rc < 0)
546		return rtas_error_rc(rc);
547	return rc;
548}
549EXPORT_SYMBOL(rtas_get_power_level);
550
551int rtas_set_power_level(int powerdomain, int level, int *setlevel)
552{
553	int token = rtas_token("set-power-level");
554	int rc;
555
556	if (token == RTAS_UNKNOWN_SERVICE)
557		return -ENOENT;
558
559	do {
560		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
561	} while (rtas_busy_delay(rc));
562
563	if (rc < 0)
564		return rtas_error_rc(rc);
565	return rc;
566}
567EXPORT_SYMBOL(rtas_set_power_level);
568
569int rtas_get_sensor(int sensor, int index, int *state)
570{
571	int token = rtas_token("get-sensor-state");
572	int rc;
573
574	if (token == RTAS_UNKNOWN_SERVICE)
575		return -ENOENT;
576
577	do {
578		rc = rtas_call(token, 2, 2, state, sensor, index);
579	} while (rtas_busy_delay(rc));
580
581	if (rc < 0)
582		return rtas_error_rc(rc);
583	return rc;
584}
585EXPORT_SYMBOL(rtas_get_sensor);
586
587int rtas_get_sensor_fast(int sensor, int index, int *state)
588{
589	int token = rtas_token("get-sensor-state");
590	int rc;
591
592	if (token == RTAS_UNKNOWN_SERVICE)
593		return -ENOENT;
594
595	rc = rtas_call(token, 2, 2, state, sensor, index);
596	WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
597				    rc <= RTAS_EXTENDED_DELAY_MAX));
598
599	if (rc < 0)
600		return rtas_error_rc(rc);
601	return rc;
602}
603
604bool rtas_indicator_present(int token, int *maxindex)
605{
606	int proplen, count, i;
607	const struct indicator_elem {
608		__be32 token;
609		__be32 maxindex;
610	} *indicators;
611
612	indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
613	if (!indicators)
614		return false;
615
616	count = proplen / sizeof(struct indicator_elem);
617
618	for (i = 0; i < count; i++) {
619		if (__be32_to_cpu(indicators[i].token) != token)
620			continue;
621		if (maxindex)
622			*maxindex = __be32_to_cpu(indicators[i].maxindex);
623		return true;
624	}
625
626	return false;
627}
628EXPORT_SYMBOL(rtas_indicator_present);
629
630int rtas_set_indicator(int indicator, int index, int new_value)
631{
632	int token = rtas_token("set-indicator");
633	int rc;
634
635	if (token == RTAS_UNKNOWN_SERVICE)
636		return -ENOENT;
637
638	do {
639		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
640	} while (rtas_busy_delay(rc));
641
642	if (rc < 0)
643		return rtas_error_rc(rc);
644	return rc;
645}
646EXPORT_SYMBOL(rtas_set_indicator);
647
648/*
649 * Ignoring RTAS extended delay
650 */
651int rtas_set_indicator_fast(int indicator, int index, int new_value)
652{
653	int rc;
654	int token = rtas_token("set-indicator");
655
656	if (token == RTAS_UNKNOWN_SERVICE)
657		return -ENOENT;
658
659	rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
660
661	WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
662
663	if (rc < 0)
664		return rtas_error_rc(rc);
665
666	return rc;
667}
668
669void rtas_restart(char *cmd)
670{
671	if (rtas_flash_term_hook)
672		rtas_flash_term_hook(SYS_RESTART);
673	printk("RTAS system-reboot returned %d\n",
674	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
675	for (;;);
676}
677
678void rtas_power_off(void)
679{
680	if (rtas_flash_term_hook)
681		rtas_flash_term_hook(SYS_POWER_OFF);
682	/* allow power on only with power button press */
683	printk("RTAS power-off returned %d\n",
684	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
685	for (;;);
686}
687
688void rtas_halt(void)
689{
690	if (rtas_flash_term_hook)
691		rtas_flash_term_hook(SYS_HALT);
692	/* allow power on only with power button press */
693	printk("RTAS power-off returned %d\n",
694	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
695	for (;;);
696}
697
698/* Must be in the RMO region, so we place it here */
699static char rtas_os_term_buf[2048];
700
701void rtas_os_term(char *str)
702{
703	int status;
704
705	/*
706	 * Firmware with the ibm,extended-os-term property is guaranteed
707	 * to always return from an ibm,os-term call. Earlier versions without
708	 * this property may terminate the partition which we want to avoid
709	 * since it interferes with panic_timeout.
710	 */
711	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
712	    RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
713		return;
714
715	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
716
717	do {
718		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
719				   __pa(rtas_os_term_buf));
720	} while (rtas_busy_delay(status));
721
722	if (status != 0)
723		printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
724}
725
726static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
727#ifdef CONFIG_PPC_PSERIES
728static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
729{
730	u16 slb_size = mmu_slb_size;
731	int rc = H_MULTI_THREADS_ACTIVE;
732	int cpu;
733
734	slb_set_size(SLB_MIN_SIZE);
735	printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id());
736
737	while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) &&
738	       !atomic_read(&data->error))
739		rc = rtas_call(data->token, 0, 1, NULL);
740
741	if (rc || atomic_read(&data->error)) {
742		printk(KERN_DEBUG "ibm,suspend-me returned %d\n", rc);
743		slb_set_size(slb_size);
744	}
745
746	if (atomic_read(&data->error))
747		rc = atomic_read(&data->error);
748
749	atomic_set(&data->error, rc);
750	pSeries_coalesce_init();
751
752	if (wake_when_done) {
753		atomic_set(&data->done, 1);
754
755		for_each_online_cpu(cpu)
756			plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
757	}
758
759	if (atomic_dec_return(&data->working) == 0)
760		complete(data->complete);
761
762	return rc;
763}
764
765int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data)
766{
767	atomic_inc(&data->working);
768	return __rtas_suspend_last_cpu(data, 0);
769}
770
771static int __rtas_suspend_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
772{
773	long rc = H_SUCCESS;
774	unsigned long msr_save;
775	int cpu;
776
777	atomic_inc(&data->working);
778
779	/* really need to ensure MSR.EE is off for H_JOIN */
780	msr_save = mfmsr();
781	mtmsr(msr_save & ~(MSR_EE));
782
783	while (rc == H_SUCCESS && !atomic_read(&data->done) && !atomic_read(&data->error))
784		rc = plpar_hcall_norets(H_JOIN);
785
786	mtmsr(msr_save);
787
788	if (rc == H_SUCCESS) {
789		/* This cpu was prodded and the suspend is complete. */
790		goto out;
791	} else if (rc == H_CONTINUE) {
792		/* All other cpus are in H_JOIN, this cpu does
793		 * the suspend.
794		 */
795		return __rtas_suspend_last_cpu(data, wake_when_done);
796	} else {
797		printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
798		       smp_processor_id(), rc);
799		atomic_set(&data->error, rc);
800	}
801
802	if (wake_when_done) {
803		atomic_set(&data->done, 1);
804
805		/* This cpu did the suspend or got an error; in either case,
806		 * we need to prod all other other cpus out of join state.
807		 * Extra prods are harmless.
808		 */
809		for_each_online_cpu(cpu)
810			plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
811	}
812out:
813	if (atomic_dec_return(&data->working) == 0)
814		complete(data->complete);
815	return rc;
816}
817
818int rtas_suspend_cpu(struct rtas_suspend_me_data *data)
819{
820	return __rtas_suspend_cpu(data, 0);
821}
822
823static void rtas_percpu_suspend_me(void *info)
824{
825	__rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
826}
827
828enum rtas_cpu_state {
829	DOWN,
830	UP,
831};
832
833#ifndef CONFIG_SMP
834static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
835				cpumask_var_t cpus)
836{
837	if (!cpumask_empty(cpus)) {
838		cpumask_clear(cpus);
839		return -EINVAL;
840	} else
841		return 0;
842}
843#else
844/* On return cpumask will be altered to indicate CPUs changed.
845 * CPUs with states changed will be set in the mask,
846 * CPUs with status unchanged will be unset in the mask. */
847static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
848				cpumask_var_t cpus)
849{
850	int cpu;
851	int cpuret = 0;
852	int ret = 0;
853
854	if (cpumask_empty(cpus))
855		return 0;
856
857	for_each_cpu(cpu, cpus) {
858		switch (state) {
859		case DOWN:
860			cpuret = cpu_down(cpu);
861			break;
862		case UP:
863			cpuret = cpu_up(cpu);
864			break;
865		}
866		if (cpuret) {
867			pr_debug("%s: cpu_%s for cpu#%d returned %d.\n",
868					__func__,
869					((state == UP) ? "up" : "down"),
870					cpu, cpuret);
871			if (!ret)
872				ret = cpuret;
873			if (state == UP) {
874				/* clear bits for unchanged cpus, return */
875				cpumask_shift_right(cpus, cpus, cpu);
876				cpumask_shift_left(cpus, cpus, cpu);
877				break;
878			} else {
879				/* clear bit for unchanged cpu, continue */
880				cpumask_clear_cpu(cpu, cpus);
881			}
882		}
883	}
884
885	return ret;
886}
887#endif
888
889int rtas_online_cpus_mask(cpumask_var_t cpus)
890{
891	int ret;
892
893	ret = rtas_cpu_state_change_mask(UP, cpus);
894
895	if (ret) {
896		cpumask_var_t tmp_mask;
897
898		if (!alloc_cpumask_var(&tmp_mask, GFP_TEMPORARY))
899			return ret;
900
901		/* Use tmp_mask to preserve cpus mask from first failure */
902		cpumask_copy(tmp_mask, cpus);
903		rtas_offline_cpus_mask(tmp_mask);
904		free_cpumask_var(tmp_mask);
905	}
906
907	return ret;
908}
909EXPORT_SYMBOL(rtas_online_cpus_mask);
910
911int rtas_offline_cpus_mask(cpumask_var_t cpus)
912{
913	return rtas_cpu_state_change_mask(DOWN, cpus);
914}
915EXPORT_SYMBOL(rtas_offline_cpus_mask);
916
917int rtas_ibm_suspend_me(u64 handle)
918{
919	long state;
920	long rc;
921	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
922	struct rtas_suspend_me_data data;
923	DECLARE_COMPLETION_ONSTACK(done);
924	cpumask_var_t offline_mask;
925	int cpuret;
926
927	if (!rtas_service_present("ibm,suspend-me"))
928		return -ENOSYS;
929
930	/* Make sure the state is valid */
931	rc = plpar_hcall(H_VASI_STATE, retbuf, handle);
932
933	state = retbuf[0];
934
935	if (rc) {
936		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
937		return rc;
938	} else if (state == H_VASI_ENABLED) {
939		return -EAGAIN;
940	} else if (state != H_VASI_SUSPENDING) {
941		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
942		       state);
943		return -EIO;
944	}
945
946	if (!alloc_cpumask_var(&offline_mask, GFP_TEMPORARY))
947		return -ENOMEM;
948
949	atomic_set(&data.working, 0);
950	atomic_set(&data.done, 0);
951	atomic_set(&data.error, 0);
952	data.token = rtas_token("ibm,suspend-me");
953	data.complete = &done;
954
955	/* All present CPUs must be online */
956	cpumask_andnot(offline_mask, cpu_present_mask, cpu_online_mask);
957	cpuret = rtas_online_cpus_mask(offline_mask);
958	if (cpuret) {
959		pr_err("%s: Could not bring present CPUs online.\n", __func__);
960		atomic_set(&data.error, cpuret);
961		goto out;
962	}
963
964	stop_topology_update();
965
966	/* Call function on all CPUs.  One of us will make the
967	 * rtas call
968	 */
969	if (on_each_cpu(rtas_percpu_suspend_me, &data, 0))
970		atomic_set(&data.error, -EINVAL);
971
972	wait_for_completion(&done);
973
974	if (atomic_read(&data.error) != 0)
975		printk(KERN_ERR "Error doing global join\n");
976
977	start_topology_update();
978
979	/* Take down CPUs not online prior to suspend */
980	cpuret = rtas_offline_cpus_mask(offline_mask);
981	if (cpuret)
982		pr_warn("%s: Could not restore CPUs to offline state.\n",
983				__func__);
984
985out:
986	free_cpumask_var(offline_mask);
987	return atomic_read(&data.error);
988}
989#else /* CONFIG_PPC_PSERIES */
990int rtas_ibm_suspend_me(u64 handle)
991{
992	return -ENOSYS;
993}
994#endif
995
996/**
997 * Find a specific pseries error log in an RTAS extended event log.
998 * @log: RTAS error/event log
999 * @section_id: two character section identifier
1000 *
1001 * Returns a pointer to the specified errorlog or NULL if not found.
1002 */
1003struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
1004					      uint16_t section_id)
1005{
1006	struct rtas_ext_event_log_v6 *ext_log =
1007		(struct rtas_ext_event_log_v6 *)log->buffer;
1008	struct pseries_errorlog *sect;
1009	unsigned char *p, *log_end;
1010	uint32_t ext_log_length = rtas_error_extended_log_length(log);
1011	uint8_t log_format = rtas_ext_event_log_format(ext_log);
1012	uint32_t company_id = rtas_ext_event_company_id(ext_log);
1013
1014	/* Check that we understand the format */
1015	if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
1016	    log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
1017	    company_id != RTAS_V6EXT_COMPANY_ID_IBM)
1018		return NULL;
1019
1020	log_end = log->buffer + ext_log_length;
1021	p = ext_log->vendor_log;
1022
1023	while (p < log_end) {
1024		sect = (struct pseries_errorlog *)p;
1025		if (pseries_errorlog_id(sect) == section_id)
1026			return sect;
1027		p += pseries_errorlog_length(sect);
1028	}
1029
1030	return NULL;
1031}
1032
1033/* We assume to be passed big endian arguments */
1034asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
1035{
1036	struct rtas_args args;
1037	unsigned long flags;
1038	char *buff_copy, *errbuf = NULL;
1039	int nargs, nret, token;
1040
1041	if (!capable(CAP_SYS_ADMIN))
1042		return -EPERM;
1043
1044	if (!rtas.entry)
1045		return -EINVAL;
1046
1047	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1048		return -EFAULT;
1049
1050	nargs = be32_to_cpu(args.nargs);
1051	nret  = be32_to_cpu(args.nret);
1052	token = be32_to_cpu(args.token);
1053
1054	if (nargs > ARRAY_SIZE(args.args)
1055	    || nret > ARRAY_SIZE(args.args)
1056	    || nargs + nret > ARRAY_SIZE(args.args))
1057		return -EINVAL;
1058
1059	/* Copy in args. */
1060	if (copy_from_user(args.args, uargs->args,
1061			   nargs * sizeof(rtas_arg_t)) != 0)
1062		return -EFAULT;
1063
1064	if (token == RTAS_UNKNOWN_SERVICE)
1065		return -EINVAL;
1066
1067	args.rets = &args.args[nargs];
1068	memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1069
1070	/* Need to handle ibm,suspend_me call specially */
1071	if (token == ibm_suspend_me_token) {
1072
1073		/*
1074		 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1075		 * endian, or at least the hcall within it requires it.
1076		 */
1077		int rc = 0;
1078		u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1079		              | be32_to_cpu(args.args[1]);
1080		rc = rtas_ibm_suspend_me(handle);
1081		if (rc == -EAGAIN)
1082			args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1083		else if (rc == -EIO)
1084			args.rets[0] = cpu_to_be32(-1);
1085		else if (rc)
1086			return rc;
1087		goto copy_return;
1088	}
1089
1090	buff_copy = get_errorlog_buffer();
1091
1092	flags = lock_rtas();
1093
1094	rtas.args = args;
1095	enter_rtas(__pa(&rtas.args));
1096	args = rtas.args;
1097
1098	/* A -1 return code indicates that the last command couldn't
1099	   be completed due to a hardware error. */
1100	if (be32_to_cpu(args.rets[0]) == -1)
1101		errbuf = __fetch_rtas_last_error(buff_copy);
1102
1103	unlock_rtas(flags);
1104
1105	if (buff_copy) {
1106		if (errbuf)
1107			log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1108		kfree(buff_copy);
1109	}
1110
1111 copy_return:
1112	/* Copy out args. */
1113	if (copy_to_user(uargs->args + nargs,
1114			 args.args + nargs,
1115			 nret * sizeof(rtas_arg_t)) != 0)
1116		return -EFAULT;
1117
1118	return 0;
1119}
1120
1121/*
1122 * Call early during boot, before mem init, to retrieve the RTAS
1123 * information from the device-tree and allocate the RMO buffer for userland
1124 * accesses.
1125 */
1126void __init rtas_initialize(void)
1127{
1128	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1129
1130	/* Get RTAS dev node and fill up our "rtas" structure with infos
1131	 * about it.
1132	 */
1133	rtas.dev = of_find_node_by_name(NULL, "rtas");
1134	if (rtas.dev) {
1135		const __be32 *basep, *entryp, *sizep;
1136
1137		basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
1138		sizep = of_get_property(rtas.dev, "rtas-size", NULL);
1139		if (basep != NULL && sizep != NULL) {
1140			rtas.base = __be32_to_cpu(*basep);
1141			rtas.size = __be32_to_cpu(*sizep);
1142			entryp = of_get_property(rtas.dev,
1143					"linux,rtas-entry", NULL);
1144			if (entryp == NULL) /* Ugh */
1145				rtas.entry = rtas.base;
1146			else
1147				rtas.entry = __be32_to_cpu(*entryp);
1148		} else
1149			rtas.dev = NULL;
1150	}
1151	if (!rtas.dev)
1152		return;
1153
1154	/* If RTAS was found, allocate the RMO buffer for it and look for
1155	 * the stop-self token if any
1156	 */
1157#ifdef CONFIG_PPC64
1158	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
1159		rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1160		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
1161	}
1162#endif
1163	rtas_rmo_buf = memblock_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
1164
1165#ifdef CONFIG_RTAS_ERROR_LOGGING
1166	rtas_last_error_token = rtas_token("rtas-last-error");
1167#endif
1168}
1169
1170int __init early_init_dt_scan_rtas(unsigned long node,
1171		const char *uname, int depth, void *data)
1172{
1173	const u32 *basep, *entryp, *sizep;
1174
1175	if (depth != 1 || strcmp(uname, "rtas") != 0)
1176		return 0;
1177
1178	basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1179	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1180	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
1181
1182	if (basep && entryp && sizep) {
1183		rtas.base = *basep;
1184		rtas.entry = *entryp;
1185		rtas.size = *sizep;
1186	}
1187
1188#ifdef CONFIG_UDBG_RTAS_CONSOLE
1189	basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1190	if (basep)
1191		rtas_putchar_token = *basep;
1192
1193	basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1194	if (basep)
1195		rtas_getchar_token = *basep;
1196
1197	if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1198	    rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1199		udbg_init_rtas_console();
1200
1201#endif
1202
1203	/* break now */
1204	return 1;
1205}
1206
1207static arch_spinlock_t timebase_lock;
1208static u64 timebase = 0;
1209
1210void rtas_give_timebase(void)
1211{
1212	unsigned long flags;
1213
1214	local_irq_save(flags);
1215	hard_irq_disable();
1216	arch_spin_lock(&timebase_lock);
1217	rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1218	timebase = get_tb();
1219	arch_spin_unlock(&timebase_lock);
1220
1221	while (timebase)
1222		barrier();
1223	rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1224	local_irq_restore(flags);
1225}
1226
1227void rtas_take_timebase(void)
1228{
1229	while (!timebase)
1230		barrier();
1231	arch_spin_lock(&timebase_lock);
1232	set_tb(timebase >> 32, timebase & 0xffffffff);
1233	timebase = 0;
1234	arch_spin_unlock(&timebase_lock);
1235}
1236