xref: /openbmc/linux/arch/powerpc/kernel/rtas.c (revision 64c70b1c)
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 = of_find_node_by_path("/rtas"))) {
196 			if ((p = of_get_property(root,
197 					"ibm,display-line-length", NULL)))
198 				display_width = *p;
199 			if ((p = of_get_property(root,
200 					"ibm,form-feed", NULL)))
201 				form_feed = *p;
202 			if ((p = of_get_property(root,
203 					"ibm,display-number-of-lines", NULL)))
204 				display_lines = *p;
205 			row_width = of_get_property(root,
206 					"ibm,display-truncation-length", NULL);
207 			of_node_put(root);
208 		}
209 		display_character = rtas_token("display-character");
210 		set_indicator = rtas_token("set-indicator");
211 	}
212 
213 	if (display_character == RTAS_UNKNOWN_SERVICE) {
214 		/* use hex display if available */
215 		if (set_indicator != RTAS_UNKNOWN_SERVICE)
216 			rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
217 		return;
218 	}
219 
220 	spin_lock(&progress_lock);
221 
222 	/*
223 	 * Last write ended with newline, but we didn't print it since
224 	 * it would just clear the bottom line of output. Print it now
225 	 * instead.
226 	 *
227 	 * If no newline is pending and form feed is supported, clear the
228 	 * display with a form feed; otherwise, print a CR to start output
229 	 * at the beginning of the line.
230 	 */
231 	if (pending_newline) {
232 		rtas_call(display_character, 1, 1, NULL, '\r');
233 		rtas_call(display_character, 1, 1, NULL, '\n');
234 		pending_newline = 0;
235 	} else {
236 		current_line = 0;
237 		if (form_feed)
238 			rtas_call(display_character, 1, 1, NULL,
239 				  (char)form_feed);
240 		else
241 			rtas_call(display_character, 1, 1, NULL, '\r');
242 	}
243 
244 	if (row_width)
245 		width = row_width[current_line];
246 	else
247 		width = display_width;
248 	os = s;
249 	while (*os) {
250 		if (*os == '\n' || *os == '\r') {
251 			/* If newline is the last character, save it
252 			 * until next call to avoid bumping up the
253 			 * display output.
254 			 */
255 			if (*os == '\n' && !os[1]) {
256 				pending_newline = 1;
257 				current_line++;
258 				if (current_line > display_lines-1)
259 					current_line = display_lines-1;
260 				spin_unlock(&progress_lock);
261 				return;
262 			}
263 
264 			/* RTAS wants CR-LF, not just LF */
265 
266 			if (*os == '\n') {
267 				rtas_call(display_character, 1, 1, NULL, '\r');
268 				rtas_call(display_character, 1, 1, NULL, '\n');
269 			} else {
270 				/* CR might be used to re-draw a line, so we'll
271 				 * leave it alone and not add LF.
272 				 */
273 				rtas_call(display_character, 1, 1, NULL, *os);
274 			}
275 
276 			if (row_width)
277 				width = row_width[current_line];
278 			else
279 				width = display_width;
280 		} else {
281 			width--;
282 			rtas_call(display_character, 1, 1, NULL, *os);
283 		}
284 
285 		os++;
286 
287 		/* if we overwrite the screen length */
288 		if (width <= 0)
289 			while ((*os != 0) && (*os != '\n') && (*os != '\r'))
290 				os++;
291 	}
292 
293 	spin_unlock(&progress_lock);
294 }
295 EXPORT_SYMBOL(rtas_progress);		/* needed by rtas_flash module */
296 
297 int rtas_token(const char *service)
298 {
299 	const int *tokp;
300 	if (rtas.dev == NULL)
301 		return RTAS_UNKNOWN_SERVICE;
302 	tokp = of_get_property(rtas.dev, service, NULL);
303 	return tokp ? *tokp : RTAS_UNKNOWN_SERVICE;
304 }
305 EXPORT_SYMBOL(rtas_token);
306 
307 int rtas_service_present(const char *service)
308 {
309 	return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
310 }
311 EXPORT_SYMBOL(rtas_service_present);
312 
313 #ifdef CONFIG_RTAS_ERROR_LOGGING
314 /*
315  * Return the firmware-specified size of the error log buffer
316  *  for all rtas calls that require an error buffer argument.
317  *  This includes 'check-exception' and 'rtas-last-error'.
318  */
319 int rtas_get_error_log_max(void)
320 {
321 	static int rtas_error_log_max;
322 	if (rtas_error_log_max)
323 		return rtas_error_log_max;
324 
325 	rtas_error_log_max = rtas_token ("rtas-error-log-max");
326 	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
327 	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
328 		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
329 			rtas_error_log_max);
330 		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
331 	}
332 	return rtas_error_log_max;
333 }
334 EXPORT_SYMBOL(rtas_get_error_log_max);
335 
336 
337 char rtas_err_buf[RTAS_ERROR_LOG_MAX];
338 int rtas_last_error_token;
339 
340 /** Return a copy of the detailed error text associated with the
341  *  most recent failed call to rtas.  Because the error text
342  *  might go stale if there are any other intervening rtas calls,
343  *  this routine must be called atomically with whatever produced
344  *  the error (i.e. with rtas.lock still held from the previous call).
345  */
346 static char *__fetch_rtas_last_error(char *altbuf)
347 {
348 	struct rtas_args err_args, save_args;
349 	u32 bufsz;
350 	char *buf = NULL;
351 
352 	if (rtas_last_error_token == -1)
353 		return NULL;
354 
355 	bufsz = rtas_get_error_log_max();
356 
357 	err_args.token = rtas_last_error_token;
358 	err_args.nargs = 2;
359 	err_args.nret = 1;
360 	err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf);
361 	err_args.args[1] = bufsz;
362 	err_args.args[2] = 0;
363 
364 	save_args = rtas.args;
365 	rtas.args = err_args;
366 
367 	enter_rtas(__pa(&rtas.args));
368 
369 	err_args = rtas.args;
370 	rtas.args = save_args;
371 
372 	/* Log the error in the unlikely case that there was one. */
373 	if (unlikely(err_args.args[2] == 0)) {
374 		if (altbuf) {
375 			buf = altbuf;
376 		} else {
377 			buf = rtas_err_buf;
378 			if (mem_init_done)
379 				buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
380 		}
381 		if (buf)
382 			memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
383 	}
384 
385 	return buf;
386 }
387 
388 #define get_errorlog_buffer()	kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
389 
390 #else /* CONFIG_RTAS_ERROR_LOGGING */
391 #define __fetch_rtas_last_error(x)	NULL
392 #define get_errorlog_buffer()		NULL
393 #endif
394 
395 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
396 {
397 	va_list list;
398 	int i;
399 	unsigned long s;
400 	struct rtas_args *rtas_args;
401 	char *buff_copy = NULL;
402 	int ret;
403 
404 	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
405 		return -1;
406 
407 	/* Gotta do something different here, use global lock for now... */
408 	spin_lock_irqsave(&rtas.lock, s);
409 	rtas_args = &rtas.args;
410 
411 	rtas_args->token = token;
412 	rtas_args->nargs = nargs;
413 	rtas_args->nret  = nret;
414 	rtas_args->rets  = (rtas_arg_t *)&(rtas_args->args[nargs]);
415 	va_start(list, outputs);
416 	for (i = 0; i < nargs; ++i)
417 		rtas_args->args[i] = va_arg(list, rtas_arg_t);
418 	va_end(list);
419 
420 	for (i = 0; i < nret; ++i)
421 		rtas_args->rets[i] = 0;
422 
423 	enter_rtas(__pa(rtas_args));
424 
425 	/* A -1 return code indicates that the last command couldn't
426 	   be completed due to a hardware error. */
427 	if (rtas_args->rets[0] == -1)
428 		buff_copy = __fetch_rtas_last_error(NULL);
429 
430 	if (nret > 1 && outputs != NULL)
431 		for (i = 0; i < nret-1; ++i)
432 			outputs[i] = rtas_args->rets[i+1];
433 	ret = (nret > 0)? rtas_args->rets[0]: 0;
434 
435 	/* Gotta do something different here, use global lock for now... */
436 	spin_unlock_irqrestore(&rtas.lock, s);
437 
438 	if (buff_copy) {
439 		log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
440 		if (mem_init_done)
441 			kfree(buff_copy);
442 	}
443 	return ret;
444 }
445 EXPORT_SYMBOL(rtas_call);
446 
447 /* For RTAS_BUSY (-2), delay for 1 millisecond.  For an extended busy status
448  * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
449  */
450 unsigned int rtas_busy_delay_time(int status)
451 {
452 	int order;
453 	unsigned int ms = 0;
454 
455 	if (status == RTAS_BUSY) {
456 		ms = 1;
457 	} else if (status >= 9900 && status <= 9905) {
458 		order = status - 9900;
459 		for (ms = 1; order > 0; order--)
460 			ms *= 10;
461 	}
462 
463 	return ms;
464 }
465 EXPORT_SYMBOL(rtas_busy_delay_time);
466 
467 /* For an RTAS busy status code, perform the hinted delay. */
468 unsigned int rtas_busy_delay(int status)
469 {
470 	unsigned int ms;
471 
472 	might_sleep();
473 	ms = rtas_busy_delay_time(status);
474 	if (ms)
475 		msleep(ms);
476 
477 	return ms;
478 }
479 EXPORT_SYMBOL(rtas_busy_delay);
480 
481 int rtas_error_rc(int rtas_rc)
482 {
483 	int rc;
484 
485 	switch (rtas_rc) {
486 		case -1: 		/* Hardware Error */
487 			rc = -EIO;
488 			break;
489 		case -3:		/* Bad indicator/domain/etc */
490 			rc = -EINVAL;
491 			break;
492 		case -9000:		/* Isolation error */
493 			rc = -EFAULT;
494 			break;
495 		case -9001:		/* Outstanding TCE/PTE */
496 			rc = -EEXIST;
497 			break;
498 		case -9002:		/* No usable slot */
499 			rc = -ENODEV;
500 			break;
501 		default:
502 			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
503 					__FUNCTION__, rtas_rc);
504 			rc = -ERANGE;
505 			break;
506 	}
507 	return rc;
508 }
509 
510 int rtas_get_power_level(int powerdomain, int *level)
511 {
512 	int token = rtas_token("get-power-level");
513 	int rc;
514 
515 	if (token == RTAS_UNKNOWN_SERVICE)
516 		return -ENOENT;
517 
518 	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
519 		udelay(1);
520 
521 	if (rc < 0)
522 		return rtas_error_rc(rc);
523 	return rc;
524 }
525 EXPORT_SYMBOL(rtas_get_power_level);
526 
527 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
528 {
529 	int token = rtas_token("set-power-level");
530 	int rc;
531 
532 	if (token == RTAS_UNKNOWN_SERVICE)
533 		return -ENOENT;
534 
535 	do {
536 		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
537 	} while (rtas_busy_delay(rc));
538 
539 	if (rc < 0)
540 		return rtas_error_rc(rc);
541 	return rc;
542 }
543 EXPORT_SYMBOL(rtas_set_power_level);
544 
545 int rtas_get_sensor(int sensor, int index, int *state)
546 {
547 	int token = rtas_token("get-sensor-state");
548 	int rc;
549 
550 	if (token == RTAS_UNKNOWN_SERVICE)
551 		return -ENOENT;
552 
553 	do {
554 		rc = rtas_call(token, 2, 2, state, sensor, index);
555 	} while (rtas_busy_delay(rc));
556 
557 	if (rc < 0)
558 		return rtas_error_rc(rc);
559 	return rc;
560 }
561 EXPORT_SYMBOL(rtas_get_sensor);
562 
563 int rtas_set_indicator(int indicator, int index, int new_value)
564 {
565 	int token = rtas_token("set-indicator");
566 	int rc;
567 
568 	if (token == RTAS_UNKNOWN_SERVICE)
569 		return -ENOENT;
570 
571 	do {
572 		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
573 	} while (rtas_busy_delay(rc));
574 
575 	if (rc < 0)
576 		return rtas_error_rc(rc);
577 	return rc;
578 }
579 EXPORT_SYMBOL(rtas_set_indicator);
580 
581 /*
582  * Ignoring RTAS extended delay
583  */
584 int rtas_set_indicator_fast(int indicator, int index, int new_value)
585 {
586 	int rc;
587 	int token = rtas_token("set-indicator");
588 
589 	if (token == RTAS_UNKNOWN_SERVICE)
590 		return -ENOENT;
591 
592 	rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
593 
594 	WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
595 
596 	if (rc < 0)
597 		return rtas_error_rc(rc);
598 
599 	return rc;
600 }
601 
602 void rtas_restart(char *cmd)
603 {
604 	if (rtas_flash_term_hook)
605 		rtas_flash_term_hook(SYS_RESTART);
606 	printk("RTAS system-reboot returned %d\n",
607 	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
608 	for (;;);
609 }
610 
611 void rtas_power_off(void)
612 {
613 	if (rtas_flash_term_hook)
614 		rtas_flash_term_hook(SYS_POWER_OFF);
615 	/* allow power on only with power button press */
616 	printk("RTAS power-off returned %d\n",
617 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
618 	for (;;);
619 }
620 
621 void rtas_halt(void)
622 {
623 	if (rtas_flash_term_hook)
624 		rtas_flash_term_hook(SYS_HALT);
625 	/* allow power on only with power button press */
626 	printk("RTAS power-off returned %d\n",
627 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
628 	for (;;);
629 }
630 
631 /* Must be in the RMO region, so we place it here */
632 static char rtas_os_term_buf[2048];
633 
634 void rtas_os_term(char *str)
635 {
636 	int status;
637 
638 	if (panic_timeout)
639 		return;
640 
641 	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
642 		return;
643 
644 	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
645 
646 	do {
647 		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
648 				   __pa(rtas_os_term_buf));
649 	} while (rtas_busy_delay(status));
650 
651 	if (status != 0)
652 		printk(KERN_EMERG "ibm,os-term call failed %d\n",
653 			       status);
654 }
655 
656 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
657 #ifdef CONFIG_PPC_PSERIES
658 static void rtas_percpu_suspend_me(void *info)
659 {
660 	int i;
661 	long rc;
662 	long flags;
663 	struct rtas_suspend_me_data *data =
664 		(struct rtas_suspend_me_data *)info;
665 
666 	/*
667 	 * We use "waiting" to indicate our state.  As long
668 	 * as it is >0, we are still trying to all join up.
669 	 * If it goes to 0, we have successfully joined up and
670 	 * one thread got H_CONTINUE.  If any error happens,
671 	 * we set it to <0.
672 	 */
673 	local_irq_save(flags);
674 	do {
675 		rc = plpar_hcall_norets(H_JOIN);
676 		smp_rmb();
677 	} while (rc == H_SUCCESS && data->waiting > 0);
678 	if (rc == H_SUCCESS)
679 		goto out;
680 
681 	if (rc == H_CONTINUE) {
682 		data->waiting = 0;
683 		data->args->args[data->args->nargs] =
684 			rtas_call(ibm_suspend_me_token, 0, 1, NULL);
685 		for_each_possible_cpu(i)
686 			plpar_hcall_norets(H_PROD,i);
687 	} else {
688 		data->waiting = -EBUSY;
689 		printk(KERN_ERR "Error on H_JOIN hypervisor call\n");
690 	}
691 
692 out:
693 	local_irq_restore(flags);
694 	return;
695 }
696 
697 static int rtas_ibm_suspend_me(struct rtas_args *args)
698 {
699 	int i;
700 	long state;
701 	long rc;
702 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
703 	struct rtas_suspend_me_data data;
704 
705 	/* Make sure the state is valid */
706 	rc = plpar_hcall(H_VASI_STATE, retbuf,
707 			 ((u64)args->args[0] << 32) | args->args[1]);
708 
709 	state = retbuf[0];
710 
711 	if (rc) {
712 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
713 		return rc;
714 	} else if (state == H_VASI_ENABLED) {
715 		args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
716 		return 0;
717 	} else if (state != H_VASI_SUSPENDING) {
718 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
719 		       state);
720 		args->args[args->nargs] = -1;
721 		return 0;
722 	}
723 
724 	data.waiting = 1;
725 	data.args = args;
726 
727 	/* Call function on all CPUs.  One of us will make the
728 	 * rtas call
729 	 */
730 	if (on_each_cpu(rtas_percpu_suspend_me, &data, 1, 0))
731 		data.waiting = -EINVAL;
732 
733 	if (data.waiting != 0)
734 		printk(KERN_ERR "Error doing global join\n");
735 
736 	/* Prod each CPU.  This won't hurt, and will wake
737 	 * anyone we successfully put to sleep with H_JOIN.
738 	 */
739 	for_each_possible_cpu(i)
740 		plpar_hcall_norets(H_PROD, i);
741 
742 	return data.waiting;
743 }
744 #else /* CONFIG_PPC_PSERIES */
745 static int rtas_ibm_suspend_me(struct rtas_args *args)
746 {
747 	return -ENOSYS;
748 }
749 #endif
750 
751 asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
752 {
753 	struct rtas_args args;
754 	unsigned long flags;
755 	char *buff_copy, *errbuf = NULL;
756 	int nargs;
757 	int rc;
758 
759 	if (!capable(CAP_SYS_ADMIN))
760 		return -EPERM;
761 
762 	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
763 		return -EFAULT;
764 
765 	nargs = args.nargs;
766 	if (nargs > ARRAY_SIZE(args.args)
767 	    || args.nret > ARRAY_SIZE(args.args)
768 	    || nargs + args.nret > ARRAY_SIZE(args.args))
769 		return -EINVAL;
770 
771 	/* Copy in args. */
772 	if (copy_from_user(args.args, uargs->args,
773 			   nargs * sizeof(rtas_arg_t)) != 0)
774 		return -EFAULT;
775 
776 	if (args.token == RTAS_UNKNOWN_SERVICE)
777 		return -EINVAL;
778 
779 	/* Need to handle ibm,suspend_me call specially */
780 	if (args.token == ibm_suspend_me_token) {
781 		rc = rtas_ibm_suspend_me(&args);
782 		if (rc)
783 			return rc;
784 		goto copy_return;
785 	}
786 
787 	buff_copy = get_errorlog_buffer();
788 
789 	spin_lock_irqsave(&rtas.lock, flags);
790 
791 	rtas.args = args;
792 	enter_rtas(__pa(&rtas.args));
793 	args = rtas.args;
794 
795 	args.rets = &args.args[nargs];
796 
797 	/* A -1 return code indicates that the last command couldn't
798 	   be completed due to a hardware error. */
799 	if (args.rets[0] == -1)
800 		errbuf = __fetch_rtas_last_error(buff_copy);
801 
802 	spin_unlock_irqrestore(&rtas.lock, flags);
803 
804 	if (buff_copy) {
805 		if (errbuf)
806 			log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
807 		kfree(buff_copy);
808 	}
809 
810  copy_return:
811 	/* Copy out args. */
812 	if (copy_to_user(uargs->args + nargs,
813 			 args.args + nargs,
814 			 args.nret * sizeof(rtas_arg_t)) != 0)
815 		return -EFAULT;
816 
817 	return 0;
818 }
819 
820 /*
821  * Call early during boot, before mem init or bootmem, to retrieve the RTAS
822  * informations from the device-tree and allocate the RMO buffer for userland
823  * accesses.
824  */
825 void __init rtas_initialize(void)
826 {
827 	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
828 
829 	/* Get RTAS dev node and fill up our "rtas" structure with infos
830 	 * about it.
831 	 */
832 	rtas.dev = of_find_node_by_name(NULL, "rtas");
833 	if (rtas.dev) {
834 		const u32 *basep, *entryp, *sizep;
835 
836 		basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
837 		sizep = of_get_property(rtas.dev, "rtas-size", NULL);
838 		if (basep != NULL && sizep != NULL) {
839 			rtas.base = *basep;
840 			rtas.size = *sizep;
841 			entryp = of_get_property(rtas.dev,
842 					"linux,rtas-entry", NULL);
843 			if (entryp == NULL) /* Ugh */
844 				rtas.entry = rtas.base;
845 			else
846 				rtas.entry = *entryp;
847 		} else
848 			rtas.dev = NULL;
849 	}
850 	if (!rtas.dev)
851 		return;
852 
853 	/* If RTAS was found, allocate the RMO buffer for it and look for
854 	 * the stop-self token if any
855 	 */
856 #ifdef CONFIG_PPC64
857 	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
858 		rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
859 		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
860 	}
861 #endif
862 	rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
863 
864 #ifdef CONFIG_RTAS_ERROR_LOGGING
865 	rtas_last_error_token = rtas_token("rtas-last-error");
866 #endif
867 }
868 
869 int __init early_init_dt_scan_rtas(unsigned long node,
870 		const char *uname, int depth, void *data)
871 {
872 	u32 *basep, *entryp, *sizep;
873 
874 	if (depth != 1 || strcmp(uname, "rtas") != 0)
875 		return 0;
876 
877 	basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
878 	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
879 	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
880 
881 	if (basep && entryp && sizep) {
882 		rtas.base = *basep;
883 		rtas.entry = *entryp;
884 		rtas.size = *sizep;
885 	}
886 
887 #ifdef CONFIG_UDBG_RTAS_CONSOLE
888 	basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
889 	if (basep)
890 		rtas_putchar_token = *basep;
891 
892 	basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
893 	if (basep)
894 		rtas_getchar_token = *basep;
895 
896 	if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
897 	    rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
898 		udbg_init_rtas_console();
899 
900 #endif
901 
902 	/* break now */
903 	return 1;
904 }
905