xref: /linux/arch/powerpc/kernel/rtas.c (revision f24e9f586b377749dff37554696cf3a105540c94)
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 	const static 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 #ifdef CONFIG_RTAS_ERROR_LOGGING
307 /*
308  * Return the firmware-specified size of the error log buffer
309  *  for all rtas calls that require an error buffer argument.
310  *  This includes 'check-exception' and 'rtas-last-error'.
311  */
312 int rtas_get_error_log_max(void)
313 {
314 	static int rtas_error_log_max;
315 	if (rtas_error_log_max)
316 		return rtas_error_log_max;
317 
318 	rtas_error_log_max = rtas_token ("rtas-error-log-max");
319 	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
320 	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
321 		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
322 			rtas_error_log_max);
323 		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
324 	}
325 	return rtas_error_log_max;
326 }
327 EXPORT_SYMBOL(rtas_get_error_log_max);
328 
329 
330 char rtas_err_buf[RTAS_ERROR_LOG_MAX];
331 int rtas_last_error_token;
332 
333 /** Return a copy of the detailed error text associated with the
334  *  most recent failed call to rtas.  Because the error text
335  *  might go stale if there are any other intervening rtas calls,
336  *  this routine must be called atomically with whatever produced
337  *  the error (i.e. with rtas.lock still held from the previous call).
338  */
339 static char *__fetch_rtas_last_error(char *altbuf)
340 {
341 	struct rtas_args err_args, save_args;
342 	u32 bufsz;
343 	char *buf = NULL;
344 
345 	if (rtas_last_error_token == -1)
346 		return NULL;
347 
348 	bufsz = rtas_get_error_log_max();
349 
350 	err_args.token = rtas_last_error_token;
351 	err_args.nargs = 2;
352 	err_args.nret = 1;
353 	err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf);
354 	err_args.args[1] = bufsz;
355 	err_args.args[2] = 0;
356 
357 	save_args = rtas.args;
358 	rtas.args = err_args;
359 
360 	enter_rtas(__pa(&rtas.args));
361 
362 	err_args = rtas.args;
363 	rtas.args = save_args;
364 
365 	/* Log the error in the unlikely case that there was one. */
366 	if (unlikely(err_args.args[2] == 0)) {
367 		if (altbuf) {
368 			buf = altbuf;
369 		} else {
370 			buf = rtas_err_buf;
371 			if (mem_init_done)
372 				buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
373 		}
374 		if (buf)
375 			memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
376 	}
377 
378 	return buf;
379 }
380 
381 #define get_errorlog_buffer()	kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
382 
383 #else /* CONFIG_RTAS_ERROR_LOGGING */
384 #define __fetch_rtas_last_error(x)	NULL
385 #define get_errorlog_buffer()		NULL
386 #endif
387 
388 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
389 {
390 	va_list list;
391 	int i;
392 	unsigned long s;
393 	struct rtas_args *rtas_args;
394 	char *buff_copy = NULL;
395 	int ret;
396 
397 	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
398 		return -1;
399 
400 	/* Gotta do something different here, use global lock for now... */
401 	spin_lock_irqsave(&rtas.lock, s);
402 	rtas_args = &rtas.args;
403 
404 	rtas_args->token = token;
405 	rtas_args->nargs = nargs;
406 	rtas_args->nret  = nret;
407 	rtas_args->rets  = (rtas_arg_t *)&(rtas_args->args[nargs]);
408 	va_start(list, outputs);
409 	for (i = 0; i < nargs; ++i)
410 		rtas_args->args[i] = va_arg(list, rtas_arg_t);
411 	va_end(list);
412 
413 	for (i = 0; i < nret; ++i)
414 		rtas_args->rets[i] = 0;
415 
416 	enter_rtas(__pa(rtas_args));
417 
418 	/* A -1 return code indicates that the last command couldn't
419 	   be completed due to a hardware error. */
420 	if (rtas_args->rets[0] == -1)
421 		buff_copy = __fetch_rtas_last_error(NULL);
422 
423 	if (nret > 1 && outputs != NULL)
424 		for (i = 0; i < nret-1; ++i)
425 			outputs[i] = rtas_args->rets[i+1];
426 	ret = (nret > 0)? rtas_args->rets[0]: 0;
427 
428 	/* Gotta do something different here, use global lock for now... */
429 	spin_unlock_irqrestore(&rtas.lock, s);
430 
431 	if (buff_copy) {
432 		log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
433 		if (mem_init_done)
434 			kfree(buff_copy);
435 	}
436 	return ret;
437 }
438 EXPORT_SYMBOL(rtas_call);
439 
440 /* For RTAS_BUSY (-2), delay for 1 millisecond.  For an extended busy status
441  * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
442  */
443 unsigned int rtas_busy_delay_time(int status)
444 {
445 	int order;
446 	unsigned int ms = 0;
447 
448 	if (status == RTAS_BUSY) {
449 		ms = 1;
450 	} else if (status >= 9900 && status <= 9905) {
451 		order = status - 9900;
452 		for (ms = 1; order > 0; order--)
453 			ms *= 10;
454 	}
455 
456 	return ms;
457 }
458 EXPORT_SYMBOL(rtas_busy_delay_time);
459 
460 /* For an RTAS busy status code, perform the hinted delay. */
461 unsigned int rtas_busy_delay(int status)
462 {
463 	unsigned int ms;
464 
465 	might_sleep();
466 	ms = rtas_busy_delay_time(status);
467 	if (ms)
468 		msleep(ms);
469 
470 	return ms;
471 }
472 EXPORT_SYMBOL(rtas_busy_delay);
473 
474 int rtas_error_rc(int rtas_rc)
475 {
476 	int rc;
477 
478 	switch (rtas_rc) {
479 		case -1: 		/* Hardware Error */
480 			rc = -EIO;
481 			break;
482 		case -3:		/* Bad indicator/domain/etc */
483 			rc = -EINVAL;
484 			break;
485 		case -9000:		/* Isolation error */
486 			rc = -EFAULT;
487 			break;
488 		case -9001:		/* Outstanding TCE/PTE */
489 			rc = -EEXIST;
490 			break;
491 		case -9002:		/* No usable slot */
492 			rc = -ENODEV;
493 			break;
494 		default:
495 			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
496 					__FUNCTION__, rtas_rc);
497 			rc = -ERANGE;
498 			break;
499 	}
500 	return rc;
501 }
502 
503 int rtas_get_power_level(int powerdomain, int *level)
504 {
505 	int token = rtas_token("get-power-level");
506 	int rc;
507 
508 	if (token == RTAS_UNKNOWN_SERVICE)
509 		return -ENOENT;
510 
511 	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
512 		udelay(1);
513 
514 	if (rc < 0)
515 		return rtas_error_rc(rc);
516 	return rc;
517 }
518 EXPORT_SYMBOL(rtas_get_power_level);
519 
520 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
521 {
522 	int token = rtas_token("set-power-level");
523 	int rc;
524 
525 	if (token == RTAS_UNKNOWN_SERVICE)
526 		return -ENOENT;
527 
528 	do {
529 		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
530 	} while (rtas_busy_delay(rc));
531 
532 	if (rc < 0)
533 		return rtas_error_rc(rc);
534 	return rc;
535 }
536 EXPORT_SYMBOL(rtas_set_power_level);
537 
538 int rtas_get_sensor(int sensor, int index, int *state)
539 {
540 	int token = rtas_token("get-sensor-state");
541 	int rc;
542 
543 	if (token == RTAS_UNKNOWN_SERVICE)
544 		return -ENOENT;
545 
546 	do {
547 		rc = rtas_call(token, 2, 2, state, sensor, index);
548 	} while (rtas_busy_delay(rc));
549 
550 	if (rc < 0)
551 		return rtas_error_rc(rc);
552 	return rc;
553 }
554 EXPORT_SYMBOL(rtas_get_sensor);
555 
556 int rtas_set_indicator(int indicator, int index, int new_value)
557 {
558 	int token = rtas_token("set-indicator");
559 	int rc;
560 
561 	if (token == RTAS_UNKNOWN_SERVICE)
562 		return -ENOENT;
563 
564 	do {
565 		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
566 	} while (rtas_busy_delay(rc));
567 
568 	if (rc < 0)
569 		return rtas_error_rc(rc);
570 	return rc;
571 }
572 EXPORT_SYMBOL(rtas_set_indicator);
573 
574 /*
575  * Ignoring RTAS extended delay
576  */
577 int rtas_set_indicator_fast(int indicator, int index, int new_value)
578 {
579 	int rc;
580 	int token = rtas_token("set-indicator");
581 
582 	if (token == RTAS_UNKNOWN_SERVICE)
583 		return -ENOENT;
584 
585 	rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
586 
587 	WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
588 
589 	if (rc < 0)
590 		return rtas_error_rc(rc);
591 
592 	return rc;
593 }
594 
595 void rtas_restart(char *cmd)
596 {
597 	if (rtas_flash_term_hook)
598 		rtas_flash_term_hook(SYS_RESTART);
599 	printk("RTAS system-reboot returned %d\n",
600 	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
601 	for (;;);
602 }
603 
604 void rtas_power_off(void)
605 {
606 	if (rtas_flash_term_hook)
607 		rtas_flash_term_hook(SYS_POWER_OFF);
608 	/* allow power on only with power button press */
609 	printk("RTAS power-off returned %d\n",
610 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
611 	for (;;);
612 }
613 
614 void rtas_halt(void)
615 {
616 	if (rtas_flash_term_hook)
617 		rtas_flash_term_hook(SYS_HALT);
618 	/* allow power on only with power button press */
619 	printk("RTAS power-off returned %d\n",
620 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
621 	for (;;);
622 }
623 
624 /* Must be in the RMO region, so we place it here */
625 static char rtas_os_term_buf[2048];
626 
627 void rtas_os_term(char *str)
628 {
629 	int status;
630 
631 	if (panic_timeout)
632 		return;
633 
634 	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
635 		return;
636 
637 	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
638 
639 	do {
640 		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
641 				   __pa(rtas_os_term_buf));
642 	} while (rtas_busy_delay(status));
643 
644 	if (status != 0)
645 		printk(KERN_EMERG "ibm,os-term call failed %d\n",
646 			       status);
647 }
648 
649 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
650 #ifdef CONFIG_PPC_PSERIES
651 static void rtas_percpu_suspend_me(void *info)
652 {
653 	int i;
654 	long rc;
655 	long flags;
656 	struct rtas_suspend_me_data *data =
657 		(struct rtas_suspend_me_data *)info;
658 
659 	/*
660 	 * We use "waiting" to indicate our state.  As long
661 	 * as it is >0, we are still trying to all join up.
662 	 * If it goes to 0, we have successfully joined up and
663 	 * one thread got H_CONTINUE.  If any error happens,
664 	 * we set it to <0.
665 	 */
666 	local_irq_save(flags);
667 	do {
668 		rc = plpar_hcall_norets(H_JOIN);
669 		smp_rmb();
670 	} while (rc == H_SUCCESS && data->waiting > 0);
671 	if (rc == H_SUCCESS)
672 		goto out;
673 
674 	if (rc == H_CONTINUE) {
675 		data->waiting = 0;
676 		data->args->args[data->args->nargs] =
677 			rtas_call(ibm_suspend_me_token, 0, 1, NULL);
678 		for_each_possible_cpu(i)
679 			plpar_hcall_norets(H_PROD,i);
680 	} else {
681 		data->waiting = -EBUSY;
682 		printk(KERN_ERR "Error on H_JOIN hypervisor call\n");
683 	}
684 
685 out:
686 	local_irq_restore(flags);
687 	return;
688 }
689 
690 static int rtas_ibm_suspend_me(struct rtas_args *args)
691 {
692 	int i;
693 	long state;
694 	long rc;
695 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
696 	struct rtas_suspend_me_data data;
697 
698 	/* Make sure the state is valid */
699 	rc = plpar_hcall(H_VASI_STATE, retbuf,
700 			 ((u64)args->args[0] << 32) | args->args[1]);
701 
702 	state = retbuf[0];
703 
704 	if (rc) {
705 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
706 		return rc;
707 	} else if (state == H_VASI_ENABLED) {
708 		args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
709 		return 0;
710 	} else if (state != H_VASI_SUSPENDING) {
711 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
712 		       state);
713 		args->args[args->nargs] = -1;
714 		return 0;
715 	}
716 
717 	data.waiting = 1;
718 	data.args = args;
719 
720 	/* Call function on all CPUs.  One of us will make the
721 	 * rtas call
722 	 */
723 	if (on_each_cpu(rtas_percpu_suspend_me, &data, 1, 0))
724 		data.waiting = -EINVAL;
725 
726 	if (data.waiting != 0)
727 		printk(KERN_ERR "Error doing global join\n");
728 
729 	/* Prod each CPU.  This won't hurt, and will wake
730 	 * anyone we successfully put to sleep with H_JOIN.
731 	 */
732 	for_each_possible_cpu(i)
733 		plpar_hcall_norets(H_PROD, i);
734 
735 	return data.waiting;
736 }
737 #else /* CONFIG_PPC_PSERIES */
738 static int rtas_ibm_suspend_me(struct rtas_args *args)
739 {
740 	return -ENOSYS;
741 }
742 #endif
743 
744 asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
745 {
746 	struct rtas_args args;
747 	unsigned long flags;
748 	char *buff_copy, *errbuf = NULL;
749 	int nargs;
750 	int rc;
751 
752 	if (!capable(CAP_SYS_ADMIN))
753 		return -EPERM;
754 
755 	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
756 		return -EFAULT;
757 
758 	nargs = args.nargs;
759 	if (nargs > ARRAY_SIZE(args.args)
760 	    || args.nret > ARRAY_SIZE(args.args)
761 	    || nargs + args.nret > ARRAY_SIZE(args.args))
762 		return -EINVAL;
763 
764 	/* Copy in args. */
765 	if (copy_from_user(args.args, uargs->args,
766 			   nargs * sizeof(rtas_arg_t)) != 0)
767 		return -EFAULT;
768 
769 	if (args.token == RTAS_UNKNOWN_SERVICE)
770 		return -EINVAL;
771 
772 	/* Need to handle ibm,suspend_me call specially */
773 	if (args.token == ibm_suspend_me_token) {
774 		rc = rtas_ibm_suspend_me(&args);
775 		if (rc)
776 			return rc;
777 		goto copy_return;
778 	}
779 
780 	buff_copy = get_errorlog_buffer();
781 
782 	spin_lock_irqsave(&rtas.lock, flags);
783 
784 	rtas.args = args;
785 	enter_rtas(__pa(&rtas.args));
786 	args = rtas.args;
787 
788 	args.rets = &args.args[nargs];
789 
790 	/* A -1 return code indicates that the last command couldn't
791 	   be completed due to a hardware error. */
792 	if (args.rets[0] == -1)
793 		errbuf = __fetch_rtas_last_error(buff_copy);
794 
795 	spin_unlock_irqrestore(&rtas.lock, flags);
796 
797 	if (buff_copy) {
798 		if (errbuf)
799 			log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
800 		kfree(buff_copy);
801 	}
802 
803  copy_return:
804 	/* Copy out args. */
805 	if (copy_to_user(uargs->args + nargs,
806 			 args.args + nargs,
807 			 args.nret * sizeof(rtas_arg_t)) != 0)
808 		return -EFAULT;
809 
810 	return 0;
811 }
812 
813 /* This version can't take the spinlock, because it never returns */
814 
815 struct rtas_args rtas_stop_self_args = {
816 	/* The token is initialized for real in setup_system() */
817 	.token = RTAS_UNKNOWN_SERVICE,
818 	.nargs = 0,
819 	.nret = 1,
820 	.rets = &rtas_stop_self_args.args[0],
821 };
822 
823 void rtas_stop_self(void)
824 {
825 	struct rtas_args *rtas_args = &rtas_stop_self_args;
826 
827 	local_irq_disable();
828 
829 	BUG_ON(rtas_args->token == RTAS_UNKNOWN_SERVICE);
830 
831 	printk("cpu %u (hwid %u) Ready to die...\n",
832 	       smp_processor_id(), hard_smp_processor_id());
833 	enter_rtas(__pa(rtas_args));
834 
835 	panic("Alas, I survived.\n");
836 }
837 
838 /*
839  * Call early during boot, before mem init or bootmem, to retrieve the RTAS
840  * informations from the device-tree and allocate the RMO buffer for userland
841  * accesses.
842  */
843 void __init rtas_initialize(void)
844 {
845 	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
846 
847 	/* Get RTAS dev node and fill up our "rtas" structure with infos
848 	 * about it.
849 	 */
850 	rtas.dev = of_find_node_by_name(NULL, "rtas");
851 	if (rtas.dev) {
852 		const u32 *basep, *entryp, *sizep;
853 
854 		basep = get_property(rtas.dev, "linux,rtas-base", NULL);
855 		sizep = get_property(rtas.dev, "rtas-size", NULL);
856 		if (basep != NULL && sizep != NULL) {
857 			rtas.base = *basep;
858 			rtas.size = *sizep;
859 			entryp = get_property(rtas.dev,
860 					"linux,rtas-entry", NULL);
861 			if (entryp == NULL) /* Ugh */
862 				rtas.entry = rtas.base;
863 			else
864 				rtas.entry = *entryp;
865 		} else
866 			rtas.dev = NULL;
867 	}
868 	if (!rtas.dev)
869 		return;
870 
871 	/* If RTAS was found, allocate the RMO buffer for it and look for
872 	 * the stop-self token if any
873 	 */
874 #ifdef CONFIG_PPC64
875 	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
876 		rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
877 		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
878 	}
879 #endif
880 	rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
881 
882 #ifdef CONFIG_HOTPLUG_CPU
883 	rtas_stop_self_args.token = rtas_token("stop-self");
884 #endif /* CONFIG_HOTPLUG_CPU */
885 #ifdef CONFIG_RTAS_ERROR_LOGGING
886 	rtas_last_error_token = rtas_token("rtas-last-error");
887 #endif
888 }
889 
890 int __init early_init_dt_scan_rtas(unsigned long node,
891 		const char *uname, int depth, void *data)
892 {
893 	u32 *basep, *entryp, *sizep;
894 
895 	if (depth != 1 || strcmp(uname, "rtas") != 0)
896 		return 0;
897 
898 	basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
899 	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
900 	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
901 
902 	if (basep && entryp && sizep) {
903 		rtas.base = *basep;
904 		rtas.entry = *entryp;
905 		rtas.size = *sizep;
906 	}
907 
908 #ifdef CONFIG_UDBG_RTAS_CONSOLE
909 	basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
910 	if (basep)
911 		rtas_putchar_token = *basep;
912 
913 	basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
914 	if (basep)
915 		rtas_getchar_token = *basep;
916 
917 	if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
918 	    rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
919 		udbg_init_rtas_console();
920 
921 #endif
922 
923 	/* break now */
924 	return 1;
925 }
926