xref: /linux/arch/powerpc/kernel/rtas.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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/module.h>
19 #include <linux/init.h>
20 #include <linux/capability.h>
21 #include <linux/delay.h>
22 
23 #include <asm/prom.h>
24 #include <asm/rtas.h>
25 #include <asm/hvcall.h>
26 #include <asm/semaphore.h>
27 #include <asm/machdep.h>
28 #include <asm/firmware.h>
29 #include <asm/page.h>
30 #include <asm/param.h>
31 #include <asm/system.h>
32 #include <asm/delay.h>
33 #include <asm/uaccess.h>
34 #include <asm/lmb.h>
35 #include <asm/udbg.h>
36 #include <asm/syscalls.h>
37 
38 struct rtas_t rtas = {
39 	.lock = SPIN_LOCK_UNLOCKED
40 };
41 EXPORT_SYMBOL(rtas);
42 
43 struct rtas_suspend_me_data {
44 	long waiting;
45 	struct rtas_args *args;
46 };
47 
48 DEFINE_SPINLOCK(rtas_data_buf_lock);
49 EXPORT_SYMBOL(rtas_data_buf_lock);
50 
51 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
52 EXPORT_SYMBOL(rtas_data_buf);
53 
54 unsigned long rtas_rmo_buf;
55 
56 /*
57  * If non-NULL, this gets called when the kernel terminates.
58  * This is done like this so rtas_flash can be a module.
59  */
60 void (*rtas_flash_term_hook)(int);
61 EXPORT_SYMBOL(rtas_flash_term_hook);
62 
63 /*
64  * call_rtas_display_status and call_rtas_display_status_delay
65  * are designed only for very early low-level debugging, which
66  * is why the token is hard-coded to 10.
67  */
68 static void call_rtas_display_status(char c)
69 {
70 	struct rtas_args *args = &rtas.args;
71 	unsigned long s;
72 
73 	if (!rtas.base)
74 		return;
75 	spin_lock_irqsave(&rtas.lock, s);
76 
77 	args->token = 10;
78 	args->nargs = 1;
79 	args->nret  = 1;
80 	args->rets  = (rtas_arg_t *)&(args->args[1]);
81 	args->args[0] = (unsigned char)c;
82 
83 	enter_rtas(__pa(args));
84 
85 	spin_unlock_irqrestore(&rtas.lock, s);
86 }
87 
88 static void call_rtas_display_status_delay(char c)
89 {
90 	static int pending_newline = 0;  /* did last write end with unprinted newline? */
91 	static int width = 16;
92 
93 	if (c == '\n') {
94 		while (width-- > 0)
95 			call_rtas_display_status(' ');
96 		width = 16;
97 		mdelay(500);
98 		pending_newline = 1;
99 	} else {
100 		if (pending_newline) {
101 			call_rtas_display_status('\r');
102 			call_rtas_display_status('\n');
103 		}
104 		pending_newline = 0;
105 		if (width--) {
106 			call_rtas_display_status(c);
107 			udelay(10000);
108 		}
109 	}
110 }
111 
112 void __init udbg_init_rtas_panel(void)
113 {
114 	udbg_putc = call_rtas_display_status_delay;
115 }
116 
117 #ifdef CONFIG_UDBG_RTAS_CONSOLE
118 
119 /* If you think you're dying before early_init_dt_scan_rtas() does its
120  * work, you can hard code the token values for your firmware here and
121  * hardcode rtas.base/entry etc.
122  */
123 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
124 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
125 
126 static void udbg_rtascon_putc(char c)
127 {
128 	int tries;
129 
130 	if (!rtas.base)
131 		return;
132 
133 	/* Add CRs before LFs */
134 	if (c == '\n')
135 		udbg_rtascon_putc('\r');
136 
137 	/* if there is more than one character to be displayed, wait a bit */
138 	for (tries = 0; tries < 16; tries++) {
139 		if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
140 			break;
141 		udelay(1000);
142 	}
143 }
144 
145 static int udbg_rtascon_getc_poll(void)
146 {
147 	int c;
148 
149 	if (!rtas.base)
150 		return -1;
151 
152 	if (rtas_call(rtas_getchar_token, 0, 2, &c))
153 		return -1;
154 
155 	return c;
156 }
157 
158 static int udbg_rtascon_getc(void)
159 {
160 	int c;
161 
162 	while ((c = udbg_rtascon_getc_poll()) == -1)
163 		;
164 
165 	return c;
166 }
167 
168 
169 void __init udbg_init_rtas_console(void)
170 {
171 	udbg_putc = udbg_rtascon_putc;
172 	udbg_getc = udbg_rtascon_getc;
173 	udbg_getc_poll = udbg_rtascon_getc_poll;
174 }
175 #endif /* CONFIG_UDBG_RTAS_CONSOLE */
176 
177 void rtas_progress(char *s, unsigned short hex)
178 {
179 	struct device_node *root;
180 	int width;
181 	const int *p;
182 	char *os;
183 	static int display_character, set_indicator;
184 	static int display_width, display_lines, form_feed;
185 	static const int *row_width;
186 	static DEFINE_SPINLOCK(progress_lock);
187 	static int current_line;
188 	static int pending_newline = 0;  /* did last write end with unprinted newline? */
189 
190 	if (!rtas.base)
191 		return;
192 
193 	if (display_width == 0) {
194 		display_width = 0x10;
195 		if ((root = find_path_device("/rtas"))) {
196 			if ((p = get_property(root,
197 					"ibm,display-line-length", NULL)))
198 				display_width = *p;
199 			if ((p = get_property(root,
200 					"ibm,form-feed", NULL)))
201 				form_feed = *p;
202 			if ((p = get_property(root,
203 					"ibm,display-number-of-lines", NULL)))
204 				display_lines = *p;
205 			row_width = get_property(root,
206 					"ibm,display-truncation-length", NULL);
207 		}
208 		display_character = rtas_token("display-character");
209 		set_indicator = rtas_token("set-indicator");
210 	}
211 
212 	if (display_character == RTAS_UNKNOWN_SERVICE) {
213 		/* use hex display if available */
214 		if (set_indicator != RTAS_UNKNOWN_SERVICE)
215 			rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
216 		return;
217 	}
218 
219 	spin_lock(&progress_lock);
220 
221 	/*
222 	 * Last write ended with newline, but we didn't print it since
223 	 * it would just clear the bottom line of output. Print it now
224 	 * instead.
225 	 *
226 	 * If no newline is pending and form feed is supported, clear the
227 	 * display with a form feed; otherwise, print a CR to start output
228 	 * at the beginning of the line.
229 	 */
230 	if (pending_newline) {
231 		rtas_call(display_character, 1, 1, NULL, '\r');
232 		rtas_call(display_character, 1, 1, NULL, '\n');
233 		pending_newline = 0;
234 	} else {
235 		current_line = 0;
236 		if (form_feed)
237 			rtas_call(display_character, 1, 1, NULL,
238 				  (char)form_feed);
239 		else
240 			rtas_call(display_character, 1, 1, NULL, '\r');
241 	}
242 
243 	if (row_width)
244 		width = row_width[current_line];
245 	else
246 		width = display_width;
247 	os = s;
248 	while (*os) {
249 		if (*os == '\n' || *os == '\r') {
250 			/* If newline is the last character, save it
251 			 * until next call to avoid bumping up the
252 			 * display output.
253 			 */
254 			if (*os == '\n' && !os[1]) {
255 				pending_newline = 1;
256 				current_line++;
257 				if (current_line > display_lines-1)
258 					current_line = display_lines-1;
259 				spin_unlock(&progress_lock);
260 				return;
261 			}
262 
263 			/* RTAS wants CR-LF, not just LF */
264 
265 			if (*os == '\n') {
266 				rtas_call(display_character, 1, 1, NULL, '\r');
267 				rtas_call(display_character, 1, 1, NULL, '\n');
268 			} else {
269 				/* CR might be used to re-draw a line, so we'll
270 				 * leave it alone and not add LF.
271 				 */
272 				rtas_call(display_character, 1, 1, NULL, *os);
273 			}
274 
275 			if (row_width)
276 				width = row_width[current_line];
277 			else
278 				width = display_width;
279 		} else {
280 			width--;
281 			rtas_call(display_character, 1, 1, NULL, *os);
282 		}
283 
284 		os++;
285 
286 		/* if we overwrite the screen length */
287 		if (width <= 0)
288 			while ((*os != 0) && (*os != '\n') && (*os != '\r'))
289 				os++;
290 	}
291 
292 	spin_unlock(&progress_lock);
293 }
294 EXPORT_SYMBOL(rtas_progress);		/* needed by rtas_flash module */
295 
296 int rtas_token(const char *service)
297 {
298 	const int *tokp;
299 	if (rtas.dev == NULL)
300 		return RTAS_UNKNOWN_SERVICE;
301 	tokp = get_property(rtas.dev, service, NULL);
302 	return tokp ? *tokp : RTAS_UNKNOWN_SERVICE;
303 }
304 EXPORT_SYMBOL(rtas_token);
305 
306 int rtas_service_present(const char *service)
307 {
308 	return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
309 }
310 EXPORT_SYMBOL(rtas_service_present);
311 
312 #ifdef CONFIG_RTAS_ERROR_LOGGING
313 /*
314  * Return the firmware-specified size of the error log buffer
315  *  for all rtas calls that require an error buffer argument.
316  *  This includes 'check-exception' and 'rtas-last-error'.
317  */
318 int rtas_get_error_log_max(void)
319 {
320 	static int rtas_error_log_max;
321 	if (rtas_error_log_max)
322 		return rtas_error_log_max;
323 
324 	rtas_error_log_max = rtas_token ("rtas-error-log-max");
325 	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
326 	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
327 		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
328 			rtas_error_log_max);
329 		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
330 	}
331 	return rtas_error_log_max;
332 }
333 EXPORT_SYMBOL(rtas_get_error_log_max);
334 
335 
336 char rtas_err_buf[RTAS_ERROR_LOG_MAX];
337 int rtas_last_error_token;
338 
339 /** Return a copy of the detailed error text associated with the
340  *  most recent failed call to rtas.  Because the error text
341  *  might go stale if there are any other intervening rtas calls,
342  *  this routine must be called atomically with whatever produced
343  *  the error (i.e. with rtas.lock still held from the previous call).
344  */
345 static char *__fetch_rtas_last_error(char *altbuf)
346 {
347 	struct rtas_args err_args, save_args;
348 	u32 bufsz;
349 	char *buf = NULL;
350 
351 	if (rtas_last_error_token == -1)
352 		return NULL;
353 
354 	bufsz = rtas_get_error_log_max();
355 
356 	err_args.token = rtas_last_error_token;
357 	err_args.nargs = 2;
358 	err_args.nret = 1;
359 	err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf);
360 	err_args.args[1] = bufsz;
361 	err_args.args[2] = 0;
362 
363 	save_args = rtas.args;
364 	rtas.args = err_args;
365 
366 	enter_rtas(__pa(&rtas.args));
367 
368 	err_args = rtas.args;
369 	rtas.args = save_args;
370 
371 	/* Log the error in the unlikely case that there was one. */
372 	if (unlikely(err_args.args[2] == 0)) {
373 		if (altbuf) {
374 			buf = altbuf;
375 		} else {
376 			buf = rtas_err_buf;
377 			if (mem_init_done)
378 				buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
379 		}
380 		if (buf)
381 			memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
382 	}
383 
384 	return buf;
385 }
386 
387 #define get_errorlog_buffer()	kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
388 
389 #else /* CONFIG_RTAS_ERROR_LOGGING */
390 #define __fetch_rtas_last_error(x)	NULL
391 #define get_errorlog_buffer()		NULL
392 #endif
393 
394 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
395 {
396 	va_list list;
397 	int i;
398 	unsigned long s;
399 	struct rtas_args *rtas_args;
400 	char *buff_copy = NULL;
401 	int ret;
402 
403 	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
404 		return -1;
405 
406 	/* Gotta do something different here, use global lock for now... */
407 	spin_lock_irqsave(&rtas.lock, s);
408 	rtas_args = &rtas.args;
409 
410 	rtas_args->token = token;
411 	rtas_args->nargs = nargs;
412 	rtas_args->nret  = nret;
413 	rtas_args->rets  = (rtas_arg_t *)&(rtas_args->args[nargs]);
414 	va_start(list, outputs);
415 	for (i = 0; i < nargs; ++i)
416 		rtas_args->args[i] = va_arg(list, rtas_arg_t);
417 	va_end(list);
418 
419 	for (i = 0; i < nret; ++i)
420 		rtas_args->rets[i] = 0;
421 
422 	enter_rtas(__pa(rtas_args));
423 
424 	/* A -1 return code indicates that the last command couldn't
425 	   be completed due to a hardware error. */
426 	if (rtas_args->rets[0] == -1)
427 		buff_copy = __fetch_rtas_last_error(NULL);
428 
429 	if (nret > 1 && outputs != NULL)
430 		for (i = 0; i < nret-1; ++i)
431 			outputs[i] = rtas_args->rets[i+1];
432 	ret = (nret > 0)? rtas_args->rets[0]: 0;
433 
434 	/* Gotta do something different here, use global lock for now... */
435 	spin_unlock_irqrestore(&rtas.lock, s);
436 
437 	if (buff_copy) {
438 		log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
439 		if (mem_init_done)
440 			kfree(buff_copy);
441 	}
442 	return ret;
443 }
444 EXPORT_SYMBOL(rtas_call);
445 
446 /* For RTAS_BUSY (-2), delay for 1 millisecond.  For an extended busy status
447  * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
448  */
449 unsigned int rtas_busy_delay_time(int status)
450 {
451 	int order;
452 	unsigned int ms = 0;
453 
454 	if (status == RTAS_BUSY) {
455 		ms = 1;
456 	} else if (status >= 9900 && status <= 9905) {
457 		order = status - 9900;
458 		for (ms = 1; order > 0; order--)
459 			ms *= 10;
460 	}
461 
462 	return ms;
463 }
464 EXPORT_SYMBOL(rtas_busy_delay_time);
465 
466 /* For an RTAS busy status code, perform the hinted delay. */
467 unsigned int rtas_busy_delay(int status)
468 {
469 	unsigned int ms;
470 
471 	might_sleep();
472 	ms = rtas_busy_delay_time(status);
473 	if (ms)
474 		msleep(ms);
475 
476 	return ms;
477 }
478 EXPORT_SYMBOL(rtas_busy_delay);
479 
480 int rtas_error_rc(int rtas_rc)
481 {
482 	int rc;
483 
484 	switch (rtas_rc) {
485 		case -1: 		/* Hardware Error */
486 			rc = -EIO;
487 			break;
488 		case -3:		/* Bad indicator/domain/etc */
489 			rc = -EINVAL;
490 			break;
491 		case -9000:		/* Isolation error */
492 			rc = -EFAULT;
493 			break;
494 		case -9001:		/* Outstanding TCE/PTE */
495 			rc = -EEXIST;
496 			break;
497 		case -9002:		/* No usable slot */
498 			rc = -ENODEV;
499 			break;
500 		default:
501 			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
502 					__FUNCTION__, rtas_rc);
503 			rc = -ERANGE;
504 			break;
505 	}
506 	return rc;
507 }
508 
509 int rtas_get_power_level(int powerdomain, int *level)
510 {
511 	int token = rtas_token("get-power-level");
512 	int rc;
513 
514 	if (token == RTAS_UNKNOWN_SERVICE)
515 		return -ENOENT;
516 
517 	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
518 		udelay(1);
519 
520 	if (rc < 0)
521 		return rtas_error_rc(rc);
522 	return rc;
523 }
524 EXPORT_SYMBOL(rtas_get_power_level);
525 
526 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
527 {
528 	int token = rtas_token("set-power-level");
529 	int rc;
530 
531 	if (token == RTAS_UNKNOWN_SERVICE)
532 		return -ENOENT;
533 
534 	do {
535 		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
536 	} while (rtas_busy_delay(rc));
537 
538 	if (rc < 0)
539 		return rtas_error_rc(rc);
540 	return rc;
541 }
542 EXPORT_SYMBOL(rtas_set_power_level);
543 
544 int rtas_get_sensor(int sensor, int index, int *state)
545 {
546 	int token = rtas_token("get-sensor-state");
547 	int rc;
548 
549 	if (token == RTAS_UNKNOWN_SERVICE)
550 		return -ENOENT;
551 
552 	do {
553 		rc = rtas_call(token, 2, 2, state, sensor, index);
554 	} while (rtas_busy_delay(rc));
555 
556 	if (rc < 0)
557 		return rtas_error_rc(rc);
558 	return rc;
559 }
560 EXPORT_SYMBOL(rtas_get_sensor);
561 
562 int rtas_set_indicator(int indicator, int index, int new_value)
563 {
564 	int token = rtas_token("set-indicator");
565 	int rc;
566 
567 	if (token == RTAS_UNKNOWN_SERVICE)
568 		return -ENOENT;
569 
570 	do {
571 		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
572 	} while (rtas_busy_delay(rc));
573 
574 	if (rc < 0)
575 		return rtas_error_rc(rc);
576 	return rc;
577 }
578 EXPORT_SYMBOL(rtas_set_indicator);
579 
580 /*
581  * Ignoring RTAS extended delay
582  */
583 int rtas_set_indicator_fast(int indicator, int index, int new_value)
584 {
585 	int rc;
586 	int token = rtas_token("set-indicator");
587 
588 	if (token == RTAS_UNKNOWN_SERVICE)
589 		return -ENOENT;
590 
591 	rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
592 
593 	WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
594 
595 	if (rc < 0)
596 		return rtas_error_rc(rc);
597 
598 	return rc;
599 }
600 
601 void rtas_restart(char *cmd)
602 {
603 	if (rtas_flash_term_hook)
604 		rtas_flash_term_hook(SYS_RESTART);
605 	printk("RTAS system-reboot returned %d\n",
606 	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
607 	for (;;);
608 }
609 
610 void rtas_power_off(void)
611 {
612 	if (rtas_flash_term_hook)
613 		rtas_flash_term_hook(SYS_POWER_OFF);
614 	/* allow power on only with power button press */
615 	printk("RTAS power-off returned %d\n",
616 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
617 	for (;;);
618 }
619 
620 void rtas_halt(void)
621 {
622 	if (rtas_flash_term_hook)
623 		rtas_flash_term_hook(SYS_HALT);
624 	/* allow power on only with power button press */
625 	printk("RTAS power-off returned %d\n",
626 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
627 	for (;;);
628 }
629 
630 /* Must be in the RMO region, so we place it here */
631 static char rtas_os_term_buf[2048];
632 
633 void rtas_os_term(char *str)
634 {
635 	int status;
636 
637 	if (panic_timeout)
638 		return;
639 
640 	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
641 		return;
642 
643 	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
644 
645 	do {
646 		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
647 				   __pa(rtas_os_term_buf));
648 	} while (rtas_busy_delay(status));
649 
650 	if (status != 0)
651 		printk(KERN_EMERG "ibm,os-term call failed %d\n",
652 			       status);
653 }
654 
655 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
656 #ifdef CONFIG_PPC_PSERIES
657 static void rtas_percpu_suspend_me(void *info)
658 {
659 	int i;
660 	long rc;
661 	long flags;
662 	struct rtas_suspend_me_data *data =
663 		(struct rtas_suspend_me_data *)info;
664 
665 	/*
666 	 * We use "waiting" to indicate our state.  As long
667 	 * as it is >0, we are still trying to all join up.
668 	 * If it goes to 0, we have successfully joined up and
669 	 * one thread got H_CONTINUE.  If any error happens,
670 	 * we set it to <0.
671 	 */
672 	local_irq_save(flags);
673 	do {
674 		rc = plpar_hcall_norets(H_JOIN);
675 		smp_rmb();
676 	} while (rc == H_SUCCESS && data->waiting > 0);
677 	if (rc == H_SUCCESS)
678 		goto out;
679 
680 	if (rc == H_CONTINUE) {
681 		data->waiting = 0;
682 		data->args->args[data->args->nargs] =
683 			rtas_call(ibm_suspend_me_token, 0, 1, NULL);
684 		for_each_possible_cpu(i)
685 			plpar_hcall_norets(H_PROD,i);
686 	} else {
687 		data->waiting = -EBUSY;
688 		printk(KERN_ERR "Error on H_JOIN hypervisor call\n");
689 	}
690 
691 out:
692 	local_irq_restore(flags);
693 	return;
694 }
695 
696 static int rtas_ibm_suspend_me(struct rtas_args *args)
697 {
698 	int i;
699 	long state;
700 	long rc;
701 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
702 	struct rtas_suspend_me_data data;
703 
704 	/* Make sure the state is valid */
705 	rc = plpar_hcall(H_VASI_STATE, retbuf,
706 			 ((u64)args->args[0] << 32) | args->args[1]);
707 
708 	state = retbuf[0];
709 
710 	if (rc) {
711 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
712 		return rc;
713 	} else if (state == H_VASI_ENABLED) {
714 		args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
715 		return 0;
716 	} else if (state != H_VASI_SUSPENDING) {
717 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
718 		       state);
719 		args->args[args->nargs] = -1;
720 		return 0;
721 	}
722 
723 	data.waiting = 1;
724 	data.args = args;
725 
726 	/* Call function on all CPUs.  One of us will make the
727 	 * rtas call
728 	 */
729 	if (on_each_cpu(rtas_percpu_suspend_me, &data, 1, 0))
730 		data.waiting = -EINVAL;
731 
732 	if (data.waiting != 0)
733 		printk(KERN_ERR "Error doing global join\n");
734 
735 	/* Prod each CPU.  This won't hurt, and will wake
736 	 * anyone we successfully put to sleep with H_JOIN.
737 	 */
738 	for_each_possible_cpu(i)
739 		plpar_hcall_norets(H_PROD, i);
740 
741 	return data.waiting;
742 }
743 #else /* CONFIG_PPC_PSERIES */
744 static int rtas_ibm_suspend_me(struct rtas_args *args)
745 {
746 	return -ENOSYS;
747 }
748 #endif
749 
750 asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
751 {
752 	struct rtas_args args;
753 	unsigned long flags;
754 	char *buff_copy, *errbuf = NULL;
755 	int nargs;
756 	int rc;
757 
758 	if (!capable(CAP_SYS_ADMIN))
759 		return -EPERM;
760 
761 	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
762 		return -EFAULT;
763 
764 	nargs = args.nargs;
765 	if (nargs > ARRAY_SIZE(args.args)
766 	    || args.nret > ARRAY_SIZE(args.args)
767 	    || nargs + args.nret > ARRAY_SIZE(args.args))
768 		return -EINVAL;
769 
770 	/* Copy in args. */
771 	if (copy_from_user(args.args, uargs->args,
772 			   nargs * sizeof(rtas_arg_t)) != 0)
773 		return -EFAULT;
774 
775 	if (args.token == RTAS_UNKNOWN_SERVICE)
776 		return -EINVAL;
777 
778 	/* Need to handle ibm,suspend_me call specially */
779 	if (args.token == ibm_suspend_me_token) {
780 		rc = rtas_ibm_suspend_me(&args);
781 		if (rc)
782 			return rc;
783 		goto copy_return;
784 	}
785 
786 	buff_copy = get_errorlog_buffer();
787 
788 	spin_lock_irqsave(&rtas.lock, flags);
789 
790 	rtas.args = args;
791 	enter_rtas(__pa(&rtas.args));
792 	args = rtas.args;
793 
794 	args.rets = &args.args[nargs];
795 
796 	/* A -1 return code indicates that the last command couldn't
797 	   be completed due to a hardware error. */
798 	if (args.rets[0] == -1)
799 		errbuf = __fetch_rtas_last_error(buff_copy);
800 
801 	spin_unlock_irqrestore(&rtas.lock, flags);
802 
803 	if (buff_copy) {
804 		if (errbuf)
805 			log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
806 		kfree(buff_copy);
807 	}
808 
809  copy_return:
810 	/* Copy out args. */
811 	if (copy_to_user(uargs->args + nargs,
812 			 args.args + nargs,
813 			 args.nret * sizeof(rtas_arg_t)) != 0)
814 		return -EFAULT;
815 
816 	return 0;
817 }
818 
819 /*
820  * Call early during boot, before mem init or bootmem, to retrieve the RTAS
821  * informations from the device-tree and allocate the RMO buffer for userland
822  * accesses.
823  */
824 void __init rtas_initialize(void)
825 {
826 	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
827 
828 	/* Get RTAS dev node and fill up our "rtas" structure with infos
829 	 * about it.
830 	 */
831 	rtas.dev = of_find_node_by_name(NULL, "rtas");
832 	if (rtas.dev) {
833 		const u32 *basep, *entryp, *sizep;
834 
835 		basep = get_property(rtas.dev, "linux,rtas-base", NULL);
836 		sizep = get_property(rtas.dev, "rtas-size", NULL);
837 		if (basep != NULL && sizep != NULL) {
838 			rtas.base = *basep;
839 			rtas.size = *sizep;
840 			entryp = get_property(rtas.dev,
841 					"linux,rtas-entry", NULL);
842 			if (entryp == NULL) /* Ugh */
843 				rtas.entry = rtas.base;
844 			else
845 				rtas.entry = *entryp;
846 		} else
847 			rtas.dev = NULL;
848 	}
849 	if (!rtas.dev)
850 		return;
851 
852 	/* If RTAS was found, allocate the RMO buffer for it and look for
853 	 * the stop-self token if any
854 	 */
855 #ifdef CONFIG_PPC64
856 	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
857 		rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
858 		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
859 	}
860 #endif
861 	rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
862 
863 #ifdef CONFIG_RTAS_ERROR_LOGGING
864 	rtas_last_error_token = rtas_token("rtas-last-error");
865 #endif
866 }
867 
868 int __init early_init_dt_scan_rtas(unsigned long node,
869 		const char *uname, int depth, void *data)
870 {
871 	u32 *basep, *entryp, *sizep;
872 
873 	if (depth != 1 || strcmp(uname, "rtas") != 0)
874 		return 0;
875 
876 	basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
877 	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
878 	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
879 
880 	if (basep && entryp && sizep) {
881 		rtas.base = *basep;
882 		rtas.entry = *entryp;
883 		rtas.size = *sizep;
884 	}
885 
886 #ifdef CONFIG_UDBG_RTAS_CONSOLE
887 	basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
888 	if (basep)
889 		rtas_putchar_token = *basep;
890 
891 	basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
892 	if (basep)
893 		rtas_getchar_token = *basep;
894 
895 	if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
896 	    rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
897 		udbg_init_rtas_console();
898 
899 #endif
900 
901 	/* break now */
902 	return 1;
903 }
904