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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 #include <linux/smp.h>
23 #include <linux/completion.h>
24 #include <linux/cpumask.h>
25 #include <linux/lmb.h>
26 
27 #include <asm/prom.h>
28 #include <asm/rtas.h>
29 #include <asm/hvcall.h>
30 #include <asm/machdep.h>
31 #include <asm/firmware.h>
32 #include <asm/page.h>
33 #include <asm/param.h>
34 #include <asm/system.h>
35 #include <asm/delay.h>
36 #include <asm/uaccess.h>
37 #include <asm/udbg.h>
38 #include <asm/syscalls.h>
39 #include <asm/smp.h>
40 #include <asm/atomic.h>
41 
42 struct rtas_t rtas = {
43 	.lock = SPIN_LOCK_UNLOCKED
44 };
45 EXPORT_SYMBOL(rtas);
46 
47 struct rtas_suspend_me_data {
48 	atomic_t working; /* number of cpus accessing this struct */
49 	int token; /* ibm,suspend-me */
50 	int error;
51 	struct completion *complete; /* wait on this until working == 0 */
52 };
53 
54 DEFINE_SPINLOCK(rtas_data_buf_lock);
55 EXPORT_SYMBOL(rtas_data_buf_lock);
56 
57 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
58 EXPORT_SYMBOL(rtas_data_buf);
59 
60 unsigned long rtas_rmo_buf;
61 
62 /*
63  * If non-NULL, this gets called when the kernel terminates.
64  * This is done like this so rtas_flash can be a module.
65  */
66 void (*rtas_flash_term_hook)(int);
67 EXPORT_SYMBOL(rtas_flash_term_hook);
68 
69 /*
70  * call_rtas_display_status and call_rtas_display_status_delay
71  * are designed only for very early low-level debugging, which
72  * is why the token is hard-coded to 10.
73  */
call_rtas_display_status(char c)74 static void call_rtas_display_status(char c)
75 {
76 	struct rtas_args *args = &rtas.args;
77 	unsigned long s;
78 
79 	if (!rtas.base)
80 		return;
81 	spin_lock_irqsave(&rtas.lock, s);
82 
83 	args->token = 10;
84 	args->nargs = 1;
85 	args->nret  = 1;
86 	args->rets  = (rtas_arg_t *)&(args->args[1]);
87 	args->args[0] = (unsigned char)c;
88 
89 	enter_rtas(__pa(args));
90 
91 	spin_unlock_irqrestore(&rtas.lock, s);
92 }
93 
call_rtas_display_status_delay(char c)94 static void call_rtas_display_status_delay(char c)
95 {
96 	static int pending_newline = 0;  /* did last write end with unprinted newline? */
97 	static int width = 16;
98 
99 	if (c == '\n') {
100 		while (width-- > 0)
101 			call_rtas_display_status(' ');
102 		width = 16;
103 		mdelay(500);
104 		pending_newline = 1;
105 	} else {
106 		if (pending_newline) {
107 			call_rtas_display_status('\r');
108 			call_rtas_display_status('\n');
109 		}
110 		pending_newline = 0;
111 		if (width--) {
112 			call_rtas_display_status(c);
113 			udelay(10000);
114 		}
115 	}
116 }
117 
udbg_init_rtas_panel(void)118 void __init udbg_init_rtas_panel(void)
119 {
120 	udbg_putc = call_rtas_display_status_delay;
121 }
122 
123 #ifdef CONFIG_UDBG_RTAS_CONSOLE
124 
125 /* If you think you're dying before early_init_dt_scan_rtas() does its
126  * work, you can hard code the token values for your firmware here and
127  * hardcode rtas.base/entry etc.
128  */
129 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
130 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
131 
udbg_rtascon_putc(char c)132 static void udbg_rtascon_putc(char c)
133 {
134 	int tries;
135 
136 	if (!rtas.base)
137 		return;
138 
139 	/* Add CRs before LFs */
140 	if (c == '\n')
141 		udbg_rtascon_putc('\r');
142 
143 	/* if there is more than one character to be displayed, wait a bit */
144 	for (tries = 0; tries < 16; tries++) {
145 		if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
146 			break;
147 		udelay(1000);
148 	}
149 }
150 
udbg_rtascon_getc_poll(void)151 static int udbg_rtascon_getc_poll(void)
152 {
153 	int c;
154 
155 	if (!rtas.base)
156 		return -1;
157 
158 	if (rtas_call(rtas_getchar_token, 0, 2, &c))
159 		return -1;
160 
161 	return c;
162 }
163 
udbg_rtascon_getc(void)164 static int udbg_rtascon_getc(void)
165 {
166 	int c;
167 
168 	while ((c = udbg_rtascon_getc_poll()) == -1)
169 		;
170 
171 	return c;
172 }
173 
174 
udbg_init_rtas_console(void)175 void __init udbg_init_rtas_console(void)
176 {
177 	udbg_putc = udbg_rtascon_putc;
178 	udbg_getc = udbg_rtascon_getc;
179 	udbg_getc_poll = udbg_rtascon_getc_poll;
180 }
181 #endif /* CONFIG_UDBG_RTAS_CONSOLE */
182 
rtas_progress(char * s,unsigned short hex)183 void rtas_progress(char *s, unsigned short hex)
184 {
185 	struct device_node *root;
186 	int width;
187 	const int *p;
188 	char *os;
189 	static int display_character, set_indicator;
190 	static int display_width, display_lines, form_feed;
191 	static const int *row_width;
192 	static DEFINE_SPINLOCK(progress_lock);
193 	static int current_line;
194 	static int pending_newline = 0;  /* did last write end with unprinted newline? */
195 
196 	if (!rtas.base)
197 		return;
198 
199 	if (display_width == 0) {
200 		display_width = 0x10;
201 		if ((root = of_find_node_by_path("/rtas"))) {
202 			if ((p = of_get_property(root,
203 					"ibm,display-line-length", NULL)))
204 				display_width = *p;
205 			if ((p = of_get_property(root,
206 					"ibm,form-feed", NULL)))
207 				form_feed = *p;
208 			if ((p = of_get_property(root,
209 					"ibm,display-number-of-lines", NULL)))
210 				display_lines = *p;
211 			row_width = of_get_property(root,
212 					"ibm,display-truncation-length", NULL);
213 			of_node_put(root);
214 		}
215 		display_character = rtas_token("display-character");
216 		set_indicator = rtas_token("set-indicator");
217 	}
218 
219 	if (display_character == RTAS_UNKNOWN_SERVICE) {
220 		/* use hex display if available */
221 		if (set_indicator != RTAS_UNKNOWN_SERVICE)
222 			rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
223 		return;
224 	}
225 
226 	spin_lock(&progress_lock);
227 
228 	/*
229 	 * Last write ended with newline, but we didn't print it since
230 	 * it would just clear the bottom line of output. Print it now
231 	 * instead.
232 	 *
233 	 * If no newline is pending and form feed is supported, clear the
234 	 * display with a form feed; otherwise, print a CR to start output
235 	 * at the beginning of the line.
236 	 */
237 	if (pending_newline) {
238 		rtas_call(display_character, 1, 1, NULL, '\r');
239 		rtas_call(display_character, 1, 1, NULL, '\n');
240 		pending_newline = 0;
241 	} else {
242 		current_line = 0;
243 		if (form_feed)
244 			rtas_call(display_character, 1, 1, NULL,
245 				  (char)form_feed);
246 		else
247 			rtas_call(display_character, 1, 1, NULL, '\r');
248 	}
249 
250 	if (row_width)
251 		width = row_width[current_line];
252 	else
253 		width = display_width;
254 	os = s;
255 	while (*os) {
256 		if (*os == '\n' || *os == '\r') {
257 			/* If newline is the last character, save it
258 			 * until next call to avoid bumping up the
259 			 * display output.
260 			 */
261 			if (*os == '\n' && !os[1]) {
262 				pending_newline = 1;
263 				current_line++;
264 				if (current_line > display_lines-1)
265 					current_line = display_lines-1;
266 				spin_unlock(&progress_lock);
267 				return;
268 			}
269 
270 			/* RTAS wants CR-LF, not just LF */
271 
272 			if (*os == '\n') {
273 				rtas_call(display_character, 1, 1, NULL, '\r');
274 				rtas_call(display_character, 1, 1, NULL, '\n');
275 			} else {
276 				/* CR might be used to re-draw a line, so we'll
277 				 * leave it alone and not add LF.
278 				 */
279 				rtas_call(display_character, 1, 1, NULL, *os);
280 			}
281 
282 			if (row_width)
283 				width = row_width[current_line];
284 			else
285 				width = display_width;
286 		} else {
287 			width--;
288 			rtas_call(display_character, 1, 1, NULL, *os);
289 		}
290 
291 		os++;
292 
293 		/* if we overwrite the screen length */
294 		if (width <= 0)
295 			while ((*os != 0) && (*os != '\n') && (*os != '\r'))
296 				os++;
297 	}
298 
299 	spin_unlock(&progress_lock);
300 }
301 EXPORT_SYMBOL(rtas_progress);		/* needed by rtas_flash module */
302 
rtas_token(const char * service)303 int rtas_token(const char *service)
304 {
305 	const int *tokp;
306 	if (rtas.dev == NULL)
307 		return RTAS_UNKNOWN_SERVICE;
308 	tokp = of_get_property(rtas.dev, service, NULL);
309 	return tokp ? *tokp : RTAS_UNKNOWN_SERVICE;
310 }
311 EXPORT_SYMBOL(rtas_token);
312 
rtas_service_present(const char * service)313 int rtas_service_present(const char *service)
314 {
315 	return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
316 }
317 EXPORT_SYMBOL(rtas_service_present);
318 
319 #ifdef CONFIG_RTAS_ERROR_LOGGING
320 /*
321  * Return the firmware-specified size of the error log buffer
322  *  for all rtas calls that require an error buffer argument.
323  *  This includes 'check-exception' and 'rtas-last-error'.
324  */
rtas_get_error_log_max(void)325 int rtas_get_error_log_max(void)
326 {
327 	static int rtas_error_log_max;
328 	if (rtas_error_log_max)
329 		return rtas_error_log_max;
330 
331 	rtas_error_log_max = rtas_token ("rtas-error-log-max");
332 	if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
333 	    (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
334 		printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
335 			rtas_error_log_max);
336 		rtas_error_log_max = RTAS_ERROR_LOG_MAX;
337 	}
338 	return rtas_error_log_max;
339 }
340 EXPORT_SYMBOL(rtas_get_error_log_max);
341 
342 
343 static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
344 static int rtas_last_error_token;
345 
346 /** Return a copy of the detailed error text associated with the
347  *  most recent failed call to rtas.  Because the error text
348  *  might go stale if there are any other intervening rtas calls,
349  *  this routine must be called atomically with whatever produced
350  *  the error (i.e. with rtas.lock still held from the previous call).
351  */
__fetch_rtas_last_error(char * altbuf)352 static char *__fetch_rtas_last_error(char *altbuf)
353 {
354 	struct rtas_args err_args, save_args;
355 	u32 bufsz;
356 	char *buf = NULL;
357 
358 	if (rtas_last_error_token == -1)
359 		return NULL;
360 
361 	bufsz = rtas_get_error_log_max();
362 
363 	err_args.token = rtas_last_error_token;
364 	err_args.nargs = 2;
365 	err_args.nret = 1;
366 	err_args.args[0] = (rtas_arg_t)__pa(rtas_err_buf);
367 	err_args.args[1] = bufsz;
368 	err_args.args[2] = 0;
369 
370 	save_args = rtas.args;
371 	rtas.args = err_args;
372 
373 	enter_rtas(__pa(&rtas.args));
374 
375 	err_args = rtas.args;
376 	rtas.args = save_args;
377 
378 	/* Log the error in the unlikely case that there was one. */
379 	if (unlikely(err_args.args[2] == 0)) {
380 		if (altbuf) {
381 			buf = altbuf;
382 		} else {
383 			buf = rtas_err_buf;
384 			if (mem_init_done)
385 				buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
386 		}
387 		if (buf)
388 			memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
389 	}
390 
391 	return buf;
392 }
393 
394 #define get_errorlog_buffer()	kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
395 
396 #else /* CONFIG_RTAS_ERROR_LOGGING */
397 #define __fetch_rtas_last_error(x)	NULL
398 #define get_errorlog_buffer()		NULL
399 #endif
400 
rtas_call(int token,int nargs,int nret,int * outputs,...)401 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
402 {
403 	va_list list;
404 	int i;
405 	unsigned long s;
406 	struct rtas_args *rtas_args;
407 	char *buff_copy = NULL;
408 	int ret;
409 
410 	if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
411 		return -1;
412 
413 	/* Gotta do something different here, use global lock for now... */
414 	spin_lock_irqsave(&rtas.lock, s);
415 	rtas_args = &rtas.args;
416 
417 	rtas_args->token = token;
418 	rtas_args->nargs = nargs;
419 	rtas_args->nret  = nret;
420 	rtas_args->rets  = (rtas_arg_t *)&(rtas_args->args[nargs]);
421 	va_start(list, outputs);
422 	for (i = 0; i < nargs; ++i)
423 		rtas_args->args[i] = va_arg(list, rtas_arg_t);
424 	va_end(list);
425 
426 	for (i = 0; i < nret; ++i)
427 		rtas_args->rets[i] = 0;
428 
429 	enter_rtas(__pa(rtas_args));
430 
431 	/* A -1 return code indicates that the last command couldn't
432 	   be completed due to a hardware error. */
433 	if (rtas_args->rets[0] == -1)
434 		buff_copy = __fetch_rtas_last_error(NULL);
435 
436 	if (nret > 1 && outputs != NULL)
437 		for (i = 0; i < nret-1; ++i)
438 			outputs[i] = rtas_args->rets[i+1];
439 	ret = (nret > 0)? rtas_args->rets[0]: 0;
440 
441 	/* Gotta do something different here, use global lock for now... */
442 	spin_unlock_irqrestore(&rtas.lock, s);
443 
444 	if (buff_copy) {
445 		log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
446 		if (mem_init_done)
447 			kfree(buff_copy);
448 	}
449 	return ret;
450 }
451 EXPORT_SYMBOL(rtas_call);
452 
453 /* For RTAS_BUSY (-2), delay for 1 millisecond.  For an extended busy status
454  * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
455  */
rtas_busy_delay_time(int status)456 unsigned int rtas_busy_delay_time(int status)
457 {
458 	int order;
459 	unsigned int ms = 0;
460 
461 	if (status == RTAS_BUSY) {
462 		ms = 1;
463 	} else if (status >= 9900 && status <= 9905) {
464 		order = status - 9900;
465 		for (ms = 1; order > 0; order--)
466 			ms *= 10;
467 	}
468 
469 	return ms;
470 }
471 EXPORT_SYMBOL(rtas_busy_delay_time);
472 
473 /* For an RTAS busy status code, perform the hinted delay. */
rtas_busy_delay(int status)474 unsigned int rtas_busy_delay(int status)
475 {
476 	unsigned int ms;
477 
478 	might_sleep();
479 	ms = rtas_busy_delay_time(status);
480 	if (ms)
481 		msleep(ms);
482 
483 	return ms;
484 }
485 EXPORT_SYMBOL(rtas_busy_delay);
486 
rtas_error_rc(int rtas_rc)487 static int rtas_error_rc(int rtas_rc)
488 {
489 	int rc;
490 
491 	switch (rtas_rc) {
492 		case -1: 		/* Hardware Error */
493 			rc = -EIO;
494 			break;
495 		case -3:		/* Bad indicator/domain/etc */
496 			rc = -EINVAL;
497 			break;
498 		case -9000:		/* Isolation error */
499 			rc = -EFAULT;
500 			break;
501 		case -9001:		/* Outstanding TCE/PTE */
502 			rc = -EEXIST;
503 			break;
504 		case -9002:		/* No usable slot */
505 			rc = -ENODEV;
506 			break;
507 		default:
508 			printk(KERN_ERR "%s: unexpected RTAS error %d\n",
509 					__func__, rtas_rc);
510 			rc = -ERANGE;
511 			break;
512 	}
513 	return rc;
514 }
515 
rtas_get_power_level(int powerdomain,int * level)516 int rtas_get_power_level(int powerdomain, int *level)
517 {
518 	int token = rtas_token("get-power-level");
519 	int rc;
520 
521 	if (token == RTAS_UNKNOWN_SERVICE)
522 		return -ENOENT;
523 
524 	while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
525 		udelay(1);
526 
527 	if (rc < 0)
528 		return rtas_error_rc(rc);
529 	return rc;
530 }
531 EXPORT_SYMBOL(rtas_get_power_level);
532 
rtas_set_power_level(int powerdomain,int level,int * setlevel)533 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
534 {
535 	int token = rtas_token("set-power-level");
536 	int rc;
537 
538 	if (token == RTAS_UNKNOWN_SERVICE)
539 		return -ENOENT;
540 
541 	do {
542 		rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
543 	} while (rtas_busy_delay(rc));
544 
545 	if (rc < 0)
546 		return rtas_error_rc(rc);
547 	return rc;
548 }
549 EXPORT_SYMBOL(rtas_set_power_level);
550 
rtas_get_sensor(int sensor,int index,int * state)551 int rtas_get_sensor(int sensor, int index, int *state)
552 {
553 	int token = rtas_token("get-sensor-state");
554 	int rc;
555 
556 	if (token == RTAS_UNKNOWN_SERVICE)
557 		return -ENOENT;
558 
559 	do {
560 		rc = rtas_call(token, 2, 2, state, sensor, index);
561 	} while (rtas_busy_delay(rc));
562 
563 	if (rc < 0)
564 		return rtas_error_rc(rc);
565 	return rc;
566 }
567 EXPORT_SYMBOL(rtas_get_sensor);
568 
rtas_indicator_present(int token,int * maxindex)569 bool rtas_indicator_present(int token, int *maxindex)
570 {
571 	int proplen, count, i;
572 	const struct indicator_elem {
573 		u32 token;
574 		u32 maxindex;
575 	} *indicators;
576 
577 	indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
578 	if (!indicators)
579 		return false;
580 
581 	count = proplen / sizeof(struct indicator_elem);
582 
583 	for (i = 0; i < count; i++) {
584 		if (indicators[i].token != token)
585 			continue;
586 		if (maxindex)
587 			*maxindex = indicators[i].maxindex;
588 		return true;
589 	}
590 
591 	return false;
592 }
593 EXPORT_SYMBOL(rtas_indicator_present);
594 
rtas_set_indicator(int indicator,int index,int new_value)595 int rtas_set_indicator(int indicator, int index, int new_value)
596 {
597 	int token = rtas_token("set-indicator");
598 	int rc;
599 
600 	if (token == RTAS_UNKNOWN_SERVICE)
601 		return -ENOENT;
602 
603 	do {
604 		rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
605 	} while (rtas_busy_delay(rc));
606 
607 	if (rc < 0)
608 		return rtas_error_rc(rc);
609 	return rc;
610 }
611 EXPORT_SYMBOL(rtas_set_indicator);
612 
613 /*
614  * Ignoring RTAS extended delay
615  */
rtas_set_indicator_fast(int indicator,int index,int new_value)616 int rtas_set_indicator_fast(int indicator, int index, int new_value)
617 {
618 	int rc;
619 	int token = rtas_token("set-indicator");
620 
621 	if (token == RTAS_UNKNOWN_SERVICE)
622 		return -ENOENT;
623 
624 	rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
625 
626 	WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
627 
628 	if (rc < 0)
629 		return rtas_error_rc(rc);
630 
631 	return rc;
632 }
633 
rtas_restart(char * cmd)634 void rtas_restart(char *cmd)
635 {
636 	if (rtas_flash_term_hook)
637 		rtas_flash_term_hook(SYS_RESTART);
638 	printk("RTAS system-reboot returned %d\n",
639 	       rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
640 	for (;;);
641 }
642 
rtas_power_off(void)643 void rtas_power_off(void)
644 {
645 	if (rtas_flash_term_hook)
646 		rtas_flash_term_hook(SYS_POWER_OFF);
647 	/* allow power on only with power button press */
648 	printk("RTAS power-off returned %d\n",
649 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
650 	for (;;);
651 }
652 
rtas_halt(void)653 void rtas_halt(void)
654 {
655 	if (rtas_flash_term_hook)
656 		rtas_flash_term_hook(SYS_HALT);
657 	/* allow power on only with power button press */
658 	printk("RTAS power-off returned %d\n",
659 	       rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
660 	for (;;);
661 }
662 
663 /* Must be in the RMO region, so we place it here */
664 static char rtas_os_term_buf[2048];
665 
rtas_os_term(char * str)666 void rtas_os_term(char *str)
667 {
668 	int status;
669 
670 	if (panic_timeout)
671 		return;
672 
673 	if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term"))
674 		return;
675 
676 	snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
677 
678 	do {
679 		status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
680 				   __pa(rtas_os_term_buf));
681 	} while (rtas_busy_delay(status));
682 
683 	if (status != 0)
684 		printk(KERN_EMERG "ibm,os-term call failed %d\n",
685 			       status);
686 }
687 
688 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
689 #ifdef CONFIG_PPC_PSERIES
rtas_percpu_suspend_me(void * info)690 static void rtas_percpu_suspend_me(void *info)
691 {
692 	long rc;
693 	unsigned long msr_save;
694 	int cpu;
695 	struct rtas_suspend_me_data *data =
696 		(struct rtas_suspend_me_data *)info;
697 
698 	atomic_inc(&data->working);
699 
700 	/* really need to ensure MSR.EE is off for H_JOIN */
701 	msr_save = mfmsr();
702 	mtmsr(msr_save & ~(MSR_EE));
703 
704 	rc = plpar_hcall_norets(H_JOIN);
705 
706 	mtmsr(msr_save);
707 
708 	if (rc == H_SUCCESS) {
709 		/* This cpu was prodded and the suspend is complete. */
710 		goto out;
711 	} else if (rc == H_CONTINUE) {
712 		/* All other cpus are in H_JOIN, this cpu does
713 		 * the suspend.
714 		 */
715 		printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n",
716 		       smp_processor_id());
717 		data->error = rtas_call(data->token, 0, 1, NULL);
718 
719 		if (data->error)
720 			printk(KERN_DEBUG "ibm,suspend-me returned %d\n",
721 			       data->error);
722 	} else {
723 		printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
724 		       smp_processor_id(), rc);
725 		data->error = rc;
726 	}
727 	/* This cpu did the suspend or got an error; in either case,
728 	 * we need to prod all other other cpus out of join state.
729 	 * Extra prods are harmless.
730 	 */
731 	for_each_online_cpu(cpu)
732 		plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
733 out:
734 	if (atomic_dec_return(&data->working) == 0)
735 		complete(data->complete);
736 }
737 
rtas_ibm_suspend_me(struct rtas_args * args)738 static int rtas_ibm_suspend_me(struct rtas_args *args)
739 {
740 	long state;
741 	long rc;
742 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
743 	struct rtas_suspend_me_data data;
744 	DECLARE_COMPLETION_ONSTACK(done);
745 
746 	if (!rtas_service_present("ibm,suspend-me"))
747 		return -ENOSYS;
748 
749 	/* Make sure the state is valid */
750 	rc = plpar_hcall(H_VASI_STATE, retbuf,
751 			 ((u64)args->args[0] << 32) | args->args[1]);
752 
753 	state = retbuf[0];
754 
755 	if (rc) {
756 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
757 		return rc;
758 	} else if (state == H_VASI_ENABLED) {
759 		args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
760 		return 0;
761 	} else if (state != H_VASI_SUSPENDING) {
762 		printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
763 		       state);
764 		args->args[args->nargs] = -1;
765 		return 0;
766 	}
767 
768 	atomic_set(&data.working, 0);
769 	data.token = rtas_token("ibm,suspend-me");
770 	data.error = 0;
771 	data.complete = &done;
772 
773 	/* Call function on all CPUs.  One of us will make the
774 	 * rtas call
775 	 */
776 	if (on_each_cpu(rtas_percpu_suspend_me, &data, 0))
777 		data.error = -EINVAL;
778 
779 	wait_for_completion(&done);
780 
781 	if (data.error != 0)
782 		printk(KERN_ERR "Error doing global join\n");
783 
784 	return data.error;
785 }
786 #else /* CONFIG_PPC_PSERIES */
rtas_ibm_suspend_me(struct rtas_args * args)787 static int rtas_ibm_suspend_me(struct rtas_args *args)
788 {
789 	return -ENOSYS;
790 }
791 #endif
792 
ppc_rtas(struct rtas_args __user * uargs)793 asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
794 {
795 	struct rtas_args args;
796 	unsigned long flags;
797 	char *buff_copy, *errbuf = NULL;
798 	int nargs;
799 	int rc;
800 
801 	if (!capable(CAP_SYS_ADMIN))
802 		return -EPERM;
803 
804 	if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
805 		return -EFAULT;
806 
807 	nargs = args.nargs;
808 	if (nargs > ARRAY_SIZE(args.args)
809 	    || args.nret > ARRAY_SIZE(args.args)
810 	    || nargs + args.nret > ARRAY_SIZE(args.args))
811 		return -EINVAL;
812 
813 	/* Copy in args. */
814 	if (copy_from_user(args.args, uargs->args,
815 			   nargs * sizeof(rtas_arg_t)) != 0)
816 		return -EFAULT;
817 
818 	if (args.token == RTAS_UNKNOWN_SERVICE)
819 		return -EINVAL;
820 
821 	args.rets = &args.args[nargs];
822 	memset(args.rets, 0, args.nret * sizeof(rtas_arg_t));
823 
824 	/* Need to handle ibm,suspend_me call specially */
825 	if (args.token == ibm_suspend_me_token) {
826 		rc = rtas_ibm_suspend_me(&args);
827 		if (rc)
828 			return rc;
829 		goto copy_return;
830 	}
831 
832 	buff_copy = get_errorlog_buffer();
833 
834 	spin_lock_irqsave(&rtas.lock, flags);
835 
836 	rtas.args = args;
837 	enter_rtas(__pa(&rtas.args));
838 	args = rtas.args;
839 
840 	/* A -1 return code indicates that the last command couldn't
841 	   be completed due to a hardware error. */
842 	if (args.rets[0] == -1)
843 		errbuf = __fetch_rtas_last_error(buff_copy);
844 
845 	spin_unlock_irqrestore(&rtas.lock, flags);
846 
847 	if (buff_copy) {
848 		if (errbuf)
849 			log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
850 		kfree(buff_copy);
851 	}
852 
853  copy_return:
854 	/* Copy out args. */
855 	if (copy_to_user(uargs->args + nargs,
856 			 args.args + nargs,
857 			 args.nret * sizeof(rtas_arg_t)) != 0)
858 		return -EFAULT;
859 
860 	return 0;
861 }
862 
863 /*
864  * Call early during boot, before mem init or bootmem, to retrieve the RTAS
865  * informations from the device-tree and allocate the RMO buffer for userland
866  * accesses.
867  */
rtas_initialize(void)868 void __init rtas_initialize(void)
869 {
870 	unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
871 
872 	/* Get RTAS dev node and fill up our "rtas" structure with infos
873 	 * about it.
874 	 */
875 	rtas.dev = of_find_node_by_name(NULL, "rtas");
876 	if (rtas.dev) {
877 		const u32 *basep, *entryp, *sizep;
878 
879 		basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
880 		sizep = of_get_property(rtas.dev, "rtas-size", NULL);
881 		if (basep != NULL && sizep != NULL) {
882 			rtas.base = *basep;
883 			rtas.size = *sizep;
884 			entryp = of_get_property(rtas.dev,
885 					"linux,rtas-entry", NULL);
886 			if (entryp == NULL) /* Ugh */
887 				rtas.entry = rtas.base;
888 			else
889 				rtas.entry = *entryp;
890 		} else
891 			rtas.dev = NULL;
892 	}
893 	if (!rtas.dev)
894 		return;
895 
896 	/* If RTAS was found, allocate the RMO buffer for it and look for
897 	 * the stop-self token if any
898 	 */
899 #ifdef CONFIG_PPC64
900 	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
901 		rtas_region = min(lmb.rmo_size, RTAS_INSTANTIATE_MAX);
902 		ibm_suspend_me_token = rtas_token("ibm,suspend-me");
903 	}
904 #endif
905 	rtas_rmo_buf = lmb_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
906 
907 #ifdef CONFIG_RTAS_ERROR_LOGGING
908 	rtas_last_error_token = rtas_token("rtas-last-error");
909 #endif
910 }
911 
early_init_dt_scan_rtas(unsigned long node,const char * uname,int depth,void * data)912 int __init early_init_dt_scan_rtas(unsigned long node,
913 		const char *uname, int depth, void *data)
914 {
915 	u32 *basep, *entryp, *sizep;
916 
917 	if (depth != 1 || strcmp(uname, "rtas") != 0)
918 		return 0;
919 
920 	basep  = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
921 	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
922 	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
923 
924 	if (basep && entryp && sizep) {
925 		rtas.base = *basep;
926 		rtas.entry = *entryp;
927 		rtas.size = *sizep;
928 	}
929 
930 #ifdef CONFIG_UDBG_RTAS_CONSOLE
931 	basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
932 	if (basep)
933 		rtas_putchar_token = *basep;
934 
935 	basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
936 	if (basep)
937 		rtas_getchar_token = *basep;
938 
939 	if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
940 	    rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
941 		udbg_init_rtas_console();
942 
943 #endif
944 
945 	/* break now */
946 	return 1;
947 }
948