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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Procedures for interfacing to the RTAS on CHRP machines.
5 *
6 * Peter Bergner, IBM March 2001.
7 * Copyright (C) 2001 IBM.
8 */
9
10#define pr_fmt(fmt) "rtas: " fmt
11
12#include <linux/capability.h>
13#include <linux/delay.h>
14#include <linux/export.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/memblock.h>
18#include <linux/of.h>
19#include <linux/of_fdt.h>
20#include <linux/reboot.h>
21#include <linux/sched.h>
22#include <linux/security.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25#include <linux/stdarg.h>
26#include <linux/syscalls.h>
27#include <linux/types.h>
28#include <linux/uaccess.h>
29
30#include <asm/delay.h>
31#include <asm/firmware.h>
32#include <asm/interrupt.h>
33#include <asm/machdep.h>
34#include <asm/mmu.h>
35#include <asm/page.h>
36#include <asm/rtas.h>
37#include <asm/time.h>
38#include <asm/udbg.h>
39
40/* This is here deliberately so it's only used in this file */
41void enter_rtas(unsigned long);
42
43static inline void do_enter_rtas(unsigned long args)
44{
45 unsigned long msr;
46
47 /*
48 * Make sure MSR[RI] is currently enabled as it will be forced later
49 * in enter_rtas.
50 */
51 msr = mfmsr();
52 BUG_ON(!(msr & MSR_RI));
53
54 BUG_ON(!irqs_disabled());
55
56 hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */
57
58 enter_rtas(args);
59
60 srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
61}
62
63struct rtas_t rtas = {
64 .lock = __ARCH_SPIN_LOCK_UNLOCKED
65};
66EXPORT_SYMBOL(rtas);
67
68DEFINE_SPINLOCK(rtas_data_buf_lock);
69EXPORT_SYMBOL(rtas_data_buf_lock);
70
71char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
72EXPORT_SYMBOL(rtas_data_buf);
73
74unsigned long rtas_rmo_buf;
75
76/*
77 * If non-NULL, this gets called when the kernel terminates.
78 * This is done like this so rtas_flash can be a module.
79 */
80void (*rtas_flash_term_hook)(int);
81EXPORT_SYMBOL(rtas_flash_term_hook);
82
83/* RTAS use home made raw locking instead of spin_lock_irqsave
84 * because those can be called from within really nasty contexts
85 * such as having the timebase stopped which would lockup with
86 * normal locks and spinlock debugging enabled
87 */
88static unsigned long lock_rtas(void)
89{
90 unsigned long flags;
91
92 local_irq_save(flags);
93 preempt_disable();
94 arch_spin_lock(&rtas.lock);
95 return flags;
96}
97
98static void unlock_rtas(unsigned long flags)
99{
100 arch_spin_unlock(&rtas.lock);
101 local_irq_restore(flags);
102 preempt_enable();
103}
104
105/*
106 * call_rtas_display_status and call_rtas_display_status_delay
107 * are designed only for very early low-level debugging, which
108 * is why the token is hard-coded to 10.
109 */
110static void call_rtas_display_status(unsigned char c)
111{
112 unsigned long s;
113
114 if (!rtas.base)
115 return;
116
117 s = lock_rtas();
118 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c);
119 unlock_rtas(s);
120}
121
122static void call_rtas_display_status_delay(char c)
123{
124 static int pending_newline = 0; /* did last write end with unprinted newline? */
125 static int width = 16;
126
127 if (c == '\n') {
128 while (width-- > 0)
129 call_rtas_display_status(' ');
130 width = 16;
131 mdelay(500);
132 pending_newline = 1;
133 } else {
134 if (pending_newline) {
135 call_rtas_display_status('\r');
136 call_rtas_display_status('\n');
137 }
138 pending_newline = 0;
139 if (width--) {
140 call_rtas_display_status(c);
141 udelay(10000);
142 }
143 }
144}
145
146void __init udbg_init_rtas_panel(void)
147{
148 udbg_putc = call_rtas_display_status_delay;
149}
150
151#ifdef CONFIG_UDBG_RTAS_CONSOLE
152
153/* If you think you're dying before early_init_dt_scan_rtas() does its
154 * work, you can hard code the token values for your firmware here and
155 * hardcode rtas.base/entry etc.
156 */
157static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
158static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
159
160static void udbg_rtascon_putc(char c)
161{
162 int tries;
163
164 if (!rtas.base)
165 return;
166
167 /* Add CRs before LFs */
168 if (c == '\n')
169 udbg_rtascon_putc('\r');
170
171 /* if there is more than one character to be displayed, wait a bit */
172 for (tries = 0; tries < 16; tries++) {
173 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
174 break;
175 udelay(1000);
176 }
177}
178
179static int udbg_rtascon_getc_poll(void)
180{
181 int c;
182
183 if (!rtas.base)
184 return -1;
185
186 if (rtas_call(rtas_getchar_token, 0, 2, &c))
187 return -1;
188
189 return c;
190}
191
192static int udbg_rtascon_getc(void)
193{
194 int c;
195
196 while ((c = udbg_rtascon_getc_poll()) == -1)
197 ;
198
199 return c;
200}
201
202
203void __init udbg_init_rtas_console(void)
204{
205 udbg_putc = udbg_rtascon_putc;
206 udbg_getc = udbg_rtascon_getc;
207 udbg_getc_poll = udbg_rtascon_getc_poll;
208}
209#endif /* CONFIG_UDBG_RTAS_CONSOLE */
210
211void rtas_progress(char *s, unsigned short hex)
212{
213 struct device_node *root;
214 int width;
215 const __be32 *p;
216 char *os;
217 static int display_character, set_indicator;
218 static int display_width, display_lines, form_feed;
219 static const int *row_width;
220 static DEFINE_SPINLOCK(progress_lock);
221 static int current_line;
222 static int pending_newline = 0; /* did last write end with unprinted newline? */
223
224 if (!rtas.base)
225 return;
226
227 if (display_width == 0) {
228 display_width = 0x10;
229 if ((root = of_find_node_by_path("/rtas"))) {
230 if ((p = of_get_property(root,
231 "ibm,display-line-length", NULL)))
232 display_width = be32_to_cpu(*p);
233 if ((p = of_get_property(root,
234 "ibm,form-feed", NULL)))
235 form_feed = be32_to_cpu(*p);
236 if ((p = of_get_property(root,
237 "ibm,display-number-of-lines", NULL)))
238 display_lines = be32_to_cpu(*p);
239 row_width = of_get_property(root,
240 "ibm,display-truncation-length", NULL);
241 of_node_put(root);
242 }
243 display_character = rtas_token("display-character");
244 set_indicator = rtas_token("set-indicator");
245 }
246
247 if (display_character == RTAS_UNKNOWN_SERVICE) {
248 /* use hex display if available */
249 if (set_indicator != RTAS_UNKNOWN_SERVICE)
250 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
251 return;
252 }
253
254 spin_lock(&progress_lock);
255
256 /*
257 * Last write ended with newline, but we didn't print it since
258 * it would just clear the bottom line of output. Print it now
259 * instead.
260 *
261 * If no newline is pending and form feed is supported, clear the
262 * display with a form feed; otherwise, print a CR to start output
263 * at the beginning of the line.
264 */
265 if (pending_newline) {
266 rtas_call(display_character, 1, 1, NULL, '\r');
267 rtas_call(display_character, 1, 1, NULL, '\n');
268 pending_newline = 0;
269 } else {
270 current_line = 0;
271 if (form_feed)
272 rtas_call(display_character, 1, 1, NULL,
273 (char)form_feed);
274 else
275 rtas_call(display_character, 1, 1, NULL, '\r');
276 }
277
278 if (row_width)
279 width = row_width[current_line];
280 else
281 width = display_width;
282 os = s;
283 while (*os) {
284 if (*os == '\n' || *os == '\r') {
285 /* If newline is the last character, save it
286 * until next call to avoid bumping up the
287 * display output.
288 */
289 if (*os == '\n' && !os[1]) {
290 pending_newline = 1;
291 current_line++;
292 if (current_line > display_lines-1)
293 current_line = display_lines-1;
294 spin_unlock(&progress_lock);
295 return;
296 }
297
298 /* RTAS wants CR-LF, not just LF */
299
300 if (*os == '\n') {
301 rtas_call(display_character, 1, 1, NULL, '\r');
302 rtas_call(display_character, 1, 1, NULL, '\n');
303 } else {
304 /* CR might be used to re-draw a line, so we'll
305 * leave it alone and not add LF.
306 */
307 rtas_call(display_character, 1, 1, NULL, *os);
308 }
309
310 if (row_width)
311 width = row_width[current_line];
312 else
313 width = display_width;
314 } else {
315 width--;
316 rtas_call(display_character, 1, 1, NULL, *os);
317 }
318
319 os++;
320
321 /* if we overwrite the screen length */
322 if (width <= 0)
323 while ((*os != 0) && (*os != '\n') && (*os != '\r'))
324 os++;
325 }
326
327 spin_unlock(&progress_lock);
328}
329EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */
330
331int rtas_token(const char *service)
332{
333 const __be32 *tokp;
334 if (rtas.dev == NULL)
335 return RTAS_UNKNOWN_SERVICE;
336 tokp = of_get_property(rtas.dev, service, NULL);
337 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
338}
339EXPORT_SYMBOL(rtas_token);
340
341int rtas_service_present(const char *service)
342{
343 return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
344}
345EXPORT_SYMBOL(rtas_service_present);
346
347#ifdef CONFIG_RTAS_ERROR_LOGGING
348
349static u32 rtas_error_log_max __ro_after_init = RTAS_ERROR_LOG_MAX;
350
351/*
352 * Return the firmware-specified size of the error log buffer
353 * for all rtas calls that require an error buffer argument.
354 * This includes 'check-exception' and 'rtas-last-error'.
355 */
356int rtas_get_error_log_max(void)
357{
358 return rtas_error_log_max;
359}
360EXPORT_SYMBOL(rtas_get_error_log_max);
361
362static void __init init_error_log_max(void)
363{
364 static const char propname[] __initconst = "rtas-error-log-max";
365 u32 max;
366
367 if (of_property_read_u32(rtas.dev, propname, &max)) {
368 pr_warn("%s not found, using default of %u\n",
369 propname, RTAS_ERROR_LOG_MAX);
370 max = RTAS_ERROR_LOG_MAX;
371 }
372
373 if (max > RTAS_ERROR_LOG_MAX) {
374 pr_warn("%s = %u, clamping max error log size to %u\n",
375 propname, max, RTAS_ERROR_LOG_MAX);
376 max = RTAS_ERROR_LOG_MAX;
377 }
378
379 rtas_error_log_max = max;
380}
381
382
383static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
384static int rtas_last_error_token;
385
386/** Return a copy of the detailed error text associated with the
387 * most recent failed call to rtas. Because the error text
388 * might go stale if there are any other intervening rtas calls,
389 * this routine must be called atomically with whatever produced
390 * the error (i.e. with rtas.lock still held from the previous call).
391 */
392static char *__fetch_rtas_last_error(char *altbuf)
393{
394 struct rtas_args err_args, save_args;
395 u32 bufsz;
396 char *buf = NULL;
397
398 if (rtas_last_error_token == -1)
399 return NULL;
400
401 bufsz = rtas_get_error_log_max();
402
403 err_args.token = cpu_to_be32(rtas_last_error_token);
404 err_args.nargs = cpu_to_be32(2);
405 err_args.nret = cpu_to_be32(1);
406 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
407 err_args.args[1] = cpu_to_be32(bufsz);
408 err_args.args[2] = 0;
409
410 save_args = rtas.args;
411 rtas.args = err_args;
412
413 do_enter_rtas(__pa(&rtas.args));
414
415 err_args = rtas.args;
416 rtas.args = save_args;
417
418 /* Log the error in the unlikely case that there was one. */
419 if (unlikely(err_args.args[2] == 0)) {
420 if (altbuf) {
421 buf = altbuf;
422 } else {
423 buf = rtas_err_buf;
424 if (slab_is_available())
425 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
426 }
427 if (buf)
428 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
429 }
430
431 return buf;
432}
433
434#define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
435
436#else /* CONFIG_RTAS_ERROR_LOGGING */
437#define __fetch_rtas_last_error(x) NULL
438#define get_errorlog_buffer() NULL
439static void __init init_error_log_max(void) {}
440#endif
441
442
443static void
444va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
445 va_list list)
446{
447 int i;
448
449 args->token = cpu_to_be32(token);
450 args->nargs = cpu_to_be32(nargs);
451 args->nret = cpu_to_be32(nret);
452 args->rets = &(args->args[nargs]);
453
454 for (i = 0; i < nargs; ++i)
455 args->args[i] = cpu_to_be32(va_arg(list, __u32));
456
457 for (i = 0; i < nret; ++i)
458 args->rets[i] = 0;
459
460 do_enter_rtas(__pa(args));
461}
462
463void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
464{
465 va_list list;
466
467 va_start(list, nret);
468 va_rtas_call_unlocked(args, token, nargs, nret, list);
469 va_end(list);
470}
471
472static int ibm_open_errinjct_token;
473static int ibm_errinjct_token;
474
475/**
476 * rtas_call() - Invoke an RTAS firmware function.
477 * @token: Identifies the function being invoked.
478 * @nargs: Number of input parameters. Does not include token.
479 * @nret: Number of output parameters, including the call status.
480 * @outputs: Array of @nret output words.
481 * @....: List of @nargs input parameters.
482 *
483 * Invokes the RTAS function indicated by @token, which the caller
484 * should obtain via rtas_token().
485 *
486 * The @nargs and @nret arguments must match the number of input and
487 * output parameters specified for the RTAS function.
488 *
489 * rtas_call() returns RTAS status codes, not conventional Linux errno
490 * values. Callers must translate any failure to an appropriate errno
491 * in syscall context. Most callers of RTAS functions that can return
492 * -2 or 990x should use rtas_busy_delay() to correctly handle those
493 * statuses before calling again.
494 *
495 * The return value descriptions are adapted from 7.2.8 [RTAS] Return
496 * Codes of the PAPR and CHRP specifications.
497 *
498 * Context: Process context preferably, interrupt context if
499 * necessary. Acquires an internal spinlock and may perform
500 * GFP_ATOMIC slab allocation in error path. Unsafe for NMI
501 * context.
502 * Return:
503 * * 0 - RTAS function call succeeded.
504 * * -1 - RTAS function encountered a hardware or
505 * platform error, or the token is invalid,
506 * or the function is restricted by kernel policy.
507 * * -2 - Specs say "A necessary hardware device was busy,
508 * and the requested function could not be
509 * performed. The operation should be retried at
510 * a later time." This is misleading, at least with
511 * respect to current RTAS implementations. What it
512 * usually means in practice is that the function
513 * could not be completed while meeting RTAS's
514 * deadline for returning control to the OS (250us
515 * for PAPR/PowerVM, typically), but the call may be
516 * immediately reattempted to resume work on it.
517 * * -3 - Parameter error.
518 * * -7 - Unexpected state change.
519 * * 9000...9899 - Vendor-specific success codes.
520 * * 9900...9905 - Advisory extended delay. Caller should try
521 * again after ~10^x ms has elapsed, where x is
522 * the last digit of the status [0-5]. Again going
523 * beyond the PAPR text, 990x on PowerVM indicates
524 * contention for RTAS-internal resources. Other
525 * RTAS call sequences in progress should be
526 * allowed to complete before reattempting the
527 * call.
528 * * -9000 - Multi-level isolation error.
529 * * -9999...-9004 - Vendor-specific error codes.
530 * * Additional negative values - Function-specific error.
531 * * Additional positive values - Function-specific success.
532 */
533int rtas_call(int token, int nargs, int nret, int *outputs, ...)
534{
535 va_list list;
536 int i;
537 unsigned long s;
538 struct rtas_args *rtas_args;
539 char *buff_copy = NULL;
540 int ret;
541
542 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
543 return -1;
544
545 if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) {
546 /*
547 * It would be nicer to not discard the error value
548 * from security_locked_down(), but callers expect an
549 * RTAS status, not an errno.
550 */
551 if (security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION))
552 return -1;
553 }
554
555 if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) {
556 WARN_ON_ONCE(1);
557 return -1;
558 }
559
560 s = lock_rtas();
561
562 /* We use the global rtas args buffer */
563 rtas_args = &rtas.args;
564
565 va_start(list, outputs);
566 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list);
567 va_end(list);
568
569 /* A -1 return code indicates that the last command couldn't
570 be completed due to a hardware error. */
571 if (be32_to_cpu(rtas_args->rets[0]) == -1)
572 buff_copy = __fetch_rtas_last_error(NULL);
573
574 if (nret > 1 && outputs != NULL)
575 for (i = 0; i < nret-1; ++i)
576 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
577 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
578
579 unlock_rtas(s);
580
581 if (buff_copy) {
582 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
583 if (slab_is_available())
584 kfree(buff_copy);
585 }
586 return ret;
587}
588EXPORT_SYMBOL(rtas_call);
589
590/**
591 * rtas_busy_delay_time() - From an RTAS status value, calculate the
592 * suggested delay time in milliseconds.
593 *
594 * @status: a value returned from rtas_call() or similar APIs which return
595 * the status of a RTAS function call.
596 *
597 * Context: Any context.
598 *
599 * Return:
600 * * 100000 - If @status is 9905.
601 * * 10000 - If @status is 9904.
602 * * 1000 - If @status is 9903.
603 * * 100 - If @status is 9902.
604 * * 10 - If @status is 9901.
605 * * 1 - If @status is either 9900 or -2. This is "wrong" for -2, but
606 * some callers depend on this behavior, and the worst outcome
607 * is that they will delay for longer than necessary.
608 * * 0 - If @status is not a busy or extended delay value.
609 */
610unsigned int rtas_busy_delay_time(int status)
611{
612 int order;
613 unsigned int ms = 0;
614
615 if (status == RTAS_BUSY) {
616 ms = 1;
617 } else if (status >= RTAS_EXTENDED_DELAY_MIN &&
618 status <= RTAS_EXTENDED_DELAY_MAX) {
619 order = status - RTAS_EXTENDED_DELAY_MIN;
620 for (ms = 1; order > 0; order--)
621 ms *= 10;
622 }
623
624 return ms;
625}
626EXPORT_SYMBOL(rtas_busy_delay_time);
627
628/**
629 * rtas_busy_delay() - helper for RTAS busy and extended delay statuses
630 *
631 * @status: a value returned from rtas_call() or similar APIs which return
632 * the status of a RTAS function call.
633 *
634 * Context: Process context. May sleep or schedule.
635 *
636 * Return:
637 * * true - @status is RTAS_BUSY or an extended delay hint. The
638 * caller may assume that the CPU has been yielded if necessary,
639 * and that an appropriate delay for @status has elapsed.
640 * Generally the caller should reattempt the RTAS call which
641 * yielded @status.
642 *
643 * * false - @status is not @RTAS_BUSY nor an extended delay hint. The
644 * caller is responsible for handling @status.
645 */
646bool rtas_busy_delay(int status)
647{
648 unsigned int ms;
649 bool ret;
650
651 switch (status) {
652 case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:
653 ret = true;
654 ms = rtas_busy_delay_time(status);
655 /*
656 * The extended delay hint can be as high as 100 seconds.
657 * Surely any function returning such a status is either
658 * buggy or isn't going to be significantly slowed by us
659 * polling at 1HZ. Clamp the sleep time to one second.
660 */
661 ms = clamp(ms, 1U, 1000U);
662 /*
663 * The delay hint is an order-of-magnitude suggestion, not
664 * a minimum. It is fine, possibly even advantageous, for
665 * us to pause for less time than hinted. For small values,
666 * use usleep_range() to ensure we don't sleep much longer
667 * than actually needed.
668 *
669 * See Documentation/timers/timers-howto.rst for
670 * explanation of the threshold used here. In effect we use
671 * usleep_range() for 9900 and 9901, msleep() for
672 * 9902-9905.
673 */
674 if (ms <= 20)
675 usleep_range(ms * 100, ms * 1000);
676 else
677 msleep(ms);
678 break;
679 case RTAS_BUSY:
680 ret = true;
681 /*
682 * We should call again immediately if there's no other
683 * work to do.
684 */
685 cond_resched();
686 break;
687 default:
688 ret = false;
689 /*
690 * Not a busy or extended delay status; the caller should
691 * handle @status itself. Ensure we warn on misuses in
692 * atomic context regardless.
693 */
694 might_sleep();
695 break;
696 }
697
698 return ret;
699}
700EXPORT_SYMBOL(rtas_busy_delay);
701
702static int rtas_error_rc(int rtas_rc)
703{
704 int rc;
705
706 switch (rtas_rc) {
707 case -1: /* Hardware Error */
708 rc = -EIO;
709 break;
710 case -3: /* Bad indicator/domain/etc */
711 rc = -EINVAL;
712 break;
713 case -9000: /* Isolation error */
714 rc = -EFAULT;
715 break;
716 case -9001: /* Outstanding TCE/PTE */
717 rc = -EEXIST;
718 break;
719 case -9002: /* No usable slot */
720 rc = -ENODEV;
721 break;
722 default:
723 pr_err("%s: unexpected error %d\n", __func__, rtas_rc);
724 rc = -ERANGE;
725 break;
726 }
727 return rc;
728}
729
730int rtas_get_power_level(int powerdomain, int *level)
731{
732 int token = rtas_token("get-power-level");
733 int rc;
734
735 if (token == RTAS_UNKNOWN_SERVICE)
736 return -ENOENT;
737
738 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
739 udelay(1);
740
741 if (rc < 0)
742 return rtas_error_rc(rc);
743 return rc;
744}
745EXPORT_SYMBOL(rtas_get_power_level);
746
747int rtas_set_power_level(int powerdomain, int level, int *setlevel)
748{
749 int token = rtas_token("set-power-level");
750 int rc;
751
752 if (token == RTAS_UNKNOWN_SERVICE)
753 return -ENOENT;
754
755 do {
756 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
757 } while (rtas_busy_delay(rc));
758
759 if (rc < 0)
760 return rtas_error_rc(rc);
761 return rc;
762}
763EXPORT_SYMBOL(rtas_set_power_level);
764
765int rtas_get_sensor(int sensor, int index, int *state)
766{
767 int token = rtas_token("get-sensor-state");
768 int rc;
769
770 if (token == RTAS_UNKNOWN_SERVICE)
771 return -ENOENT;
772
773 do {
774 rc = rtas_call(token, 2, 2, state, sensor, index);
775 } while (rtas_busy_delay(rc));
776
777 if (rc < 0)
778 return rtas_error_rc(rc);
779 return rc;
780}
781EXPORT_SYMBOL(rtas_get_sensor);
782
783int rtas_get_sensor_fast(int sensor, int index, int *state)
784{
785 int token = rtas_token("get-sensor-state");
786 int rc;
787
788 if (token == RTAS_UNKNOWN_SERVICE)
789 return -ENOENT;
790
791 rc = rtas_call(token, 2, 2, state, sensor, index);
792 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
793 rc <= RTAS_EXTENDED_DELAY_MAX));
794
795 if (rc < 0)
796 return rtas_error_rc(rc);
797 return rc;
798}
799
800bool rtas_indicator_present(int token, int *maxindex)
801{
802 int proplen, count, i;
803 const struct indicator_elem {
804 __be32 token;
805 __be32 maxindex;
806 } *indicators;
807
808 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
809 if (!indicators)
810 return false;
811
812 count = proplen / sizeof(struct indicator_elem);
813
814 for (i = 0; i < count; i++) {
815 if (__be32_to_cpu(indicators[i].token) != token)
816 continue;
817 if (maxindex)
818 *maxindex = __be32_to_cpu(indicators[i].maxindex);
819 return true;
820 }
821
822 return false;
823}
824EXPORT_SYMBOL(rtas_indicator_present);
825
826int rtas_set_indicator(int indicator, int index, int new_value)
827{
828 int token = rtas_token("set-indicator");
829 int rc;
830
831 if (token == RTAS_UNKNOWN_SERVICE)
832 return -ENOENT;
833
834 do {
835 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
836 } while (rtas_busy_delay(rc));
837
838 if (rc < 0)
839 return rtas_error_rc(rc);
840 return rc;
841}
842EXPORT_SYMBOL(rtas_set_indicator);
843
844/*
845 * Ignoring RTAS extended delay
846 */
847int rtas_set_indicator_fast(int indicator, int index, int new_value)
848{
849 int rc;
850 int token = rtas_token("set-indicator");
851
852 if (token == RTAS_UNKNOWN_SERVICE)
853 return -ENOENT;
854
855 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
856
857 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
858 rc <= RTAS_EXTENDED_DELAY_MAX));
859
860 if (rc < 0)
861 return rtas_error_rc(rc);
862
863 return rc;
864}
865
866/**
867 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR.
868 *
869 * @fw_status: RTAS call status will be placed here if not NULL.
870 *
871 * rtas_ibm_suspend_me() should be called only on a CPU which has
872 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs
873 * should be waiting to return from H_JOIN.
874 *
875 * rtas_ibm_suspend_me() may suspend execution of the OS
876 * indefinitely. Callers should take appropriate measures upon return, such as
877 * resetting watchdog facilities.
878 *
879 * Callers may choose to retry this call if @fw_status is
880 * %RTAS_THREADS_ACTIVE.
881 *
882 * Return:
883 * 0 - The partition has resumed from suspend, possibly after
884 * migration to a different host.
885 * -ECANCELED - The operation was aborted.
886 * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call.
887 * -EBUSY - Some other condition prevented the suspend from succeeding.
888 * -EIO - Hardware/platform error.
889 */
890int rtas_ibm_suspend_me(int *fw_status)
891{
892 int fwrc;
893 int ret;
894
895 fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL);
896
897 switch (fwrc) {
898 case 0:
899 ret = 0;
900 break;
901 case RTAS_SUSPEND_ABORTED:
902 ret = -ECANCELED;
903 break;
904 case RTAS_THREADS_ACTIVE:
905 ret = -EAGAIN;
906 break;
907 case RTAS_NOT_SUSPENDABLE:
908 case RTAS_OUTSTANDING_COPROC:
909 ret = -EBUSY;
910 break;
911 case -1:
912 default:
913 ret = -EIO;
914 break;
915 }
916
917 if (fw_status)
918 *fw_status = fwrc;
919
920 return ret;
921}
922
923void __noreturn rtas_restart(char *cmd)
924{
925 if (rtas_flash_term_hook)
926 rtas_flash_term_hook(SYS_RESTART);
927 pr_emerg("system-reboot returned %d\n",
928 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
929 for (;;);
930}
931
932void rtas_power_off(void)
933{
934 if (rtas_flash_term_hook)
935 rtas_flash_term_hook(SYS_POWER_OFF);
936 /* allow power on only with power button press */
937 pr_emerg("power-off returned %d\n",
938 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
939 for (;;);
940}
941
942void __noreturn rtas_halt(void)
943{
944 if (rtas_flash_term_hook)
945 rtas_flash_term_hook(SYS_HALT);
946 /* allow power on only with power button press */
947 pr_emerg("power-off returned %d\n",
948 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
949 for (;;);
950}
951
952/* Must be in the RMO region, so we place it here */
953static char rtas_os_term_buf[2048];
954static s32 ibm_os_term_token = RTAS_UNKNOWN_SERVICE;
955
956void rtas_os_term(char *str)
957{
958 int status;
959
960 /*
961 * Firmware with the ibm,extended-os-term property is guaranteed
962 * to always return from an ibm,os-term call. Earlier versions without
963 * this property may terminate the partition which we want to avoid
964 * since it interferes with panic_timeout.
965 */
966 if (ibm_os_term_token == RTAS_UNKNOWN_SERVICE)
967 return;
968
969 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
970
971 /*
972 * Keep calling as long as RTAS returns a "try again" status,
973 * but don't use rtas_busy_delay(), which potentially
974 * schedules.
975 */
976 do {
977 status = rtas_call(ibm_os_term_token, 1, 1, NULL,
978 __pa(rtas_os_term_buf));
979 } while (rtas_busy_delay_time(status));
980
981 if (status != 0)
982 pr_emerg("ibm,os-term call failed %d\n", status);
983}
984
985/**
986 * rtas_activate_firmware() - Activate a new version of firmware.
987 *
988 * Context: This function may sleep.
989 *
990 * Activate a new version of partition firmware. The OS must call this
991 * after resuming from a partition hibernation or migration in order
992 * to maintain the ability to perform live firmware updates. It's not
993 * catastrophic for this method to be absent or to fail; just log the
994 * condition in that case.
995 */
996void rtas_activate_firmware(void)
997{
998 int token;
999 int fwrc;
1000
1001 token = rtas_token("ibm,activate-firmware");
1002 if (token == RTAS_UNKNOWN_SERVICE) {
1003 pr_notice("ibm,activate-firmware method unavailable\n");
1004 return;
1005 }
1006
1007 do {
1008 fwrc = rtas_call(token, 0, 1, NULL);
1009 } while (rtas_busy_delay(fwrc));
1010
1011 if (fwrc)
1012 pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
1013}
1014
1015/**
1016 * get_pseries_errorlog() - Find a specific pseries error log in an RTAS
1017 * extended event log.
1018 * @log: RTAS error/event log
1019 * @section_id: two character section identifier
1020 *
1021 * Return: A pointer to the specified errorlog or NULL if not found.
1022 */
1023noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
1024 uint16_t section_id)
1025{
1026 struct rtas_ext_event_log_v6 *ext_log =
1027 (struct rtas_ext_event_log_v6 *)log->buffer;
1028 struct pseries_errorlog *sect;
1029 unsigned char *p, *log_end;
1030 uint32_t ext_log_length = rtas_error_extended_log_length(log);
1031 uint8_t log_format = rtas_ext_event_log_format(ext_log);
1032 uint32_t company_id = rtas_ext_event_company_id(ext_log);
1033
1034 /* Check that we understand the format */
1035 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
1036 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
1037 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
1038 return NULL;
1039
1040 log_end = log->buffer + ext_log_length;
1041 p = ext_log->vendor_log;
1042
1043 while (p < log_end) {
1044 sect = (struct pseries_errorlog *)p;
1045 if (pseries_errorlog_id(sect) == section_id)
1046 return sect;
1047 p += pseries_errorlog_length(sect);
1048 }
1049
1050 return NULL;
1051}
1052
1053/*
1054 * The sys_rtas syscall, as originally designed, allows root to pass
1055 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
1056 * can be abused to write to arbitrary memory and do other things that
1057 * are potentially harmful to system integrity, and thus should only
1058 * be used inside the kernel and not exposed to userspace.
1059 *
1060 * All known legitimate users of the sys_rtas syscall will only ever
1061 * pass addresses that fall within the RMO buffer, and use a known
1062 * subset of RTAS calls.
1063 *
1064 * Accordingly, we filter RTAS requests to check that the call is
1065 * permitted, and that provided pointers fall within the RMO buffer.
1066 * The rtas_filters list contains an entry for each permitted call,
1067 * with the indexes of the parameters which are expected to contain
1068 * addresses and sizes of buffers allocated inside the RMO buffer.
1069 */
1070struct rtas_filter {
1071 const char *name;
1072 int token;
1073 /* Indexes into the args buffer, -1 if not used */
1074 int buf_idx1;
1075 int size_idx1;
1076 int buf_idx2;
1077 int size_idx2;
1078
1079 int fixed_size;
1080};
1081
1082static struct rtas_filter rtas_filters[] __ro_after_init = {
1083 { "ibm,activate-firmware", -1, -1, -1, -1, -1 },
1084 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */
1085 { "display-character", -1, -1, -1, -1, -1 },
1086 { "ibm,display-message", -1, 0, -1, -1, -1 },
1087 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
1088 { "ibm,close-errinjct", -1, -1, -1, -1, -1 },
1089 { "ibm,open-errinjct", -1, -1, -1, -1, -1 },
1090 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
1091 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
1092 { "ibm,get-indices", -1, 2, 3, -1, -1 },
1093 { "get-power-level", -1, -1, -1, -1, -1 },
1094 { "get-sensor-state", -1, -1, -1, -1, -1 },
1095 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
1096 { "get-time-of-day", -1, -1, -1, -1, -1 },
1097 { "ibm,get-vpd", -1, 0, -1, 1, 2 },
1098 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
1099 { "ibm,platform-dump", -1, 4, 5, -1, -1 }, /* Special cased */
1100 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
1101 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
1102 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
1103 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
1104 { "set-indicator", -1, -1, -1, -1, -1 },
1105 { "set-power-level", -1, -1, -1, -1, -1 },
1106 { "set-time-for-power-on", -1, -1, -1, -1, -1 },
1107 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
1108 { "set-time-of-day", -1, -1, -1, -1, -1 },
1109#ifdef CONFIG_CPU_BIG_ENDIAN
1110 { "ibm,suspend-me", -1, -1, -1, -1, -1 },
1111 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
1112 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
1113#endif
1114 { "ibm,physical-attestation", -1, 0, 1, -1, -1 },
1115};
1116
1117static bool in_rmo_buf(u32 base, u32 end)
1118{
1119 return base >= rtas_rmo_buf &&
1120 base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) &&
1121 base <= end &&
1122 end >= rtas_rmo_buf &&
1123 end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE);
1124}
1125
1126static bool block_rtas_call(int token, int nargs,
1127 struct rtas_args *args)
1128{
1129 int i;
1130
1131 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1132 struct rtas_filter *f = &rtas_filters[i];
1133 u32 base, size, end;
1134
1135 if (token != f->token)
1136 continue;
1137
1138 if (f->buf_idx1 != -1) {
1139 base = be32_to_cpu(args->args[f->buf_idx1]);
1140 if (f->size_idx1 != -1)
1141 size = be32_to_cpu(args->args[f->size_idx1]);
1142 else if (f->fixed_size)
1143 size = f->fixed_size;
1144 else
1145 size = 1;
1146
1147 end = base + size - 1;
1148
1149 /*
1150 * Special case for ibm,platform-dump - NULL buffer
1151 * address is used to indicate end of dump processing
1152 */
1153 if (!strcmp(f->name, "ibm,platform-dump") &&
1154 base == 0)
1155 return false;
1156
1157 if (!in_rmo_buf(base, end))
1158 goto err;
1159 }
1160
1161 if (f->buf_idx2 != -1) {
1162 base = be32_to_cpu(args->args[f->buf_idx2]);
1163 if (f->size_idx2 != -1)
1164 size = be32_to_cpu(args->args[f->size_idx2]);
1165 else if (f->fixed_size)
1166 size = f->fixed_size;
1167 else
1168 size = 1;
1169 end = base + size - 1;
1170
1171 /*
1172 * Special case for ibm,configure-connector where the
1173 * address can be 0
1174 */
1175 if (!strcmp(f->name, "ibm,configure-connector") &&
1176 base == 0)
1177 return false;
1178
1179 if (!in_rmo_buf(base, end))
1180 goto err;
1181 }
1182
1183 return false;
1184 }
1185
1186err:
1187 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
1188 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
1189 token, nargs, current->comm);
1190 return true;
1191}
1192
1193static void __init rtas_syscall_filter_init(void)
1194{
1195 unsigned int i;
1196
1197 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++)
1198 rtas_filters[i].token = rtas_token(rtas_filters[i].name);
1199}
1200
1201/* We assume to be passed big endian arguments */
1202SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
1203{
1204 struct rtas_args args;
1205 unsigned long flags;
1206 char *buff_copy, *errbuf = NULL;
1207 int nargs, nret, token;
1208
1209 if (!capable(CAP_SYS_ADMIN))
1210 return -EPERM;
1211
1212 if (!rtas.entry)
1213 return -EINVAL;
1214
1215 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1216 return -EFAULT;
1217
1218 nargs = be32_to_cpu(args.nargs);
1219 nret = be32_to_cpu(args.nret);
1220 token = be32_to_cpu(args.token);
1221
1222 if (nargs >= ARRAY_SIZE(args.args)
1223 || nret > ARRAY_SIZE(args.args)
1224 || nargs + nret > ARRAY_SIZE(args.args))
1225 return -EINVAL;
1226
1227 /* Copy in args. */
1228 if (copy_from_user(args.args, uargs->args,
1229 nargs * sizeof(rtas_arg_t)) != 0)
1230 return -EFAULT;
1231
1232 if (token == RTAS_UNKNOWN_SERVICE)
1233 return -EINVAL;
1234
1235 args.rets = &args.args[nargs];
1236 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1237
1238 if (block_rtas_call(token, nargs, &args))
1239 return -EINVAL;
1240
1241 if (token == ibm_open_errinjct_token || token == ibm_errinjct_token) {
1242 int err;
1243
1244 err = security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION);
1245 if (err)
1246 return err;
1247 }
1248
1249 /* Need to handle ibm,suspend_me call specially */
1250 if (token == rtas_token("ibm,suspend-me")) {
1251
1252 /*
1253 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1254 * endian, or at least the hcall within it requires it.
1255 */
1256 int rc = 0;
1257 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1258 | be32_to_cpu(args.args[1]);
1259 rc = rtas_syscall_dispatch_ibm_suspend_me(handle);
1260 if (rc == -EAGAIN)
1261 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1262 else if (rc == -EIO)
1263 args.rets[0] = cpu_to_be32(-1);
1264 else if (rc)
1265 return rc;
1266 goto copy_return;
1267 }
1268
1269 buff_copy = get_errorlog_buffer();
1270
1271 flags = lock_rtas();
1272
1273 rtas.args = args;
1274 do_enter_rtas(__pa(&rtas.args));
1275 args = rtas.args;
1276
1277 /* A -1 return code indicates that the last command couldn't
1278 be completed due to a hardware error. */
1279 if (be32_to_cpu(args.rets[0]) == -1)
1280 errbuf = __fetch_rtas_last_error(buff_copy);
1281
1282 unlock_rtas(flags);
1283
1284 if (buff_copy) {
1285 if (errbuf)
1286 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1287 kfree(buff_copy);
1288 }
1289
1290 copy_return:
1291 /* Copy out args. */
1292 if (copy_to_user(uargs->args + nargs,
1293 args.args + nargs,
1294 nret * sizeof(rtas_arg_t)) != 0)
1295 return -EFAULT;
1296
1297 return 0;
1298}
1299
1300/*
1301 * Call early during boot, before mem init, to retrieve the RTAS
1302 * information from the device-tree and allocate the RMO buffer for userland
1303 * accesses.
1304 */
1305void __init rtas_initialize(void)
1306{
1307 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1308 u32 base, size, entry;
1309 int no_base, no_size, no_entry;
1310
1311 /* Get RTAS dev node and fill up our "rtas" structure with infos
1312 * about it.
1313 */
1314 rtas.dev = of_find_node_by_name(NULL, "rtas");
1315 if (!rtas.dev)
1316 return;
1317
1318 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
1319 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
1320 if (no_base || no_size) {
1321 of_node_put(rtas.dev);
1322 rtas.dev = NULL;
1323 return;
1324 }
1325
1326 rtas.base = base;
1327 rtas.size = size;
1328 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
1329 rtas.entry = no_entry ? rtas.base : entry;
1330
1331 init_error_log_max();
1332
1333 /*
1334 * Discover these now to avoid device tree lookups in the
1335 * panic path.
1336 */
1337 if (of_property_read_bool(rtas.dev, "ibm,extended-os-term"))
1338 ibm_os_term_token = rtas_token("ibm,os-term");
1339
1340 /* If RTAS was found, allocate the RMO buffer for it and look for
1341 * the stop-self token if any
1342 */
1343#ifdef CONFIG_PPC64
1344 if (firmware_has_feature(FW_FEATURE_LPAR))
1345 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1346#endif
1347 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE,
1348 0, rtas_region);
1349 if (!rtas_rmo_buf)
1350 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
1351 PAGE_SIZE, &rtas_region);
1352
1353#ifdef CONFIG_RTAS_ERROR_LOGGING
1354 rtas_last_error_token = rtas_token("rtas-last-error");
1355#endif
1356 ibm_open_errinjct_token = rtas_token("ibm,open-errinjct");
1357 ibm_errinjct_token = rtas_token("ibm,errinjct");
1358 rtas_syscall_filter_init();
1359}
1360
1361int __init early_init_dt_scan_rtas(unsigned long node,
1362 const char *uname, int depth, void *data)
1363{
1364 const u32 *basep, *entryp, *sizep;
1365
1366 if (depth != 1 || strcmp(uname, "rtas") != 0)
1367 return 0;
1368
1369 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1370 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1371 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1372
1373#ifdef CONFIG_PPC64
1374 /* need this feature to decide the crashkernel offset */
1375 if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL))
1376 powerpc_firmware_features |= FW_FEATURE_LPAR;
1377#endif
1378
1379 if (basep && entryp && sizep) {
1380 rtas.base = *basep;
1381 rtas.entry = *entryp;
1382 rtas.size = *sizep;
1383 }
1384
1385#ifdef CONFIG_UDBG_RTAS_CONSOLE
1386 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1387 if (basep)
1388 rtas_putchar_token = *basep;
1389
1390 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1391 if (basep)
1392 rtas_getchar_token = *basep;
1393
1394 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1395 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1396 udbg_init_rtas_console();
1397
1398#endif
1399
1400 /* break now */
1401 return 1;
1402}
1403
1404static arch_spinlock_t timebase_lock;
1405static u64 timebase = 0;
1406
1407void rtas_give_timebase(void)
1408{
1409 unsigned long flags;
1410
1411 local_irq_save(flags);
1412 hard_irq_disable();
1413 arch_spin_lock(&timebase_lock);
1414 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1415 timebase = get_tb();
1416 arch_spin_unlock(&timebase_lock);
1417
1418 while (timebase)
1419 barrier();
1420 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1421 local_irq_restore(flags);
1422}
1423
1424void rtas_take_timebase(void)
1425{
1426 while (!timebase)
1427 barrier();
1428 arch_spin_lock(&timebase_lock);
1429 set_tb(timebase >> 32, timebase & 0xffffffff);
1430 timebase = 0;
1431 arch_spin_unlock(&timebase_lock);
1432}
1/*
2 *
3 * Procedures for interfacing to the RTAS on CHRP machines.
4 *
5 * Peter Bergner, IBM March 2001.
6 * Copyright (C) 2001 IBM.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14#include <stdarg.h>
15#include <linux/kernel.h>
16#include <linux/types.h>
17#include <linux/spinlock.h>
18#include <linux/export.h>
19#include <linux/init.h>
20#include <linux/capability.h>
21#include <linux/delay.h>
22#include <linux/cpu.h>
23#include <linux/smp.h>
24#include <linux/completion.h>
25#include <linux/cpumask.h>
26#include <linux/memblock.h>
27#include <linux/slab.h>
28#include <linux/reboot.h>
29
30#include <asm/prom.h>
31#include <asm/rtas.h>
32#include <asm/hvcall.h>
33#include <asm/machdep.h>
34#include <asm/firmware.h>
35#include <asm/page.h>
36#include <asm/param.h>
37#include <asm/delay.h>
38#include <asm/uaccess.h>
39#include <asm/udbg.h>
40#include <asm/syscalls.h>
41#include <asm/smp.h>
42#include <linux/atomic.h>
43#include <asm/time.h>
44#include <asm/mmu.h>
45#include <asm/topology.h>
46
47struct rtas_t rtas = {
48 .lock = __ARCH_SPIN_LOCK_UNLOCKED
49};
50EXPORT_SYMBOL(rtas);
51
52DEFINE_SPINLOCK(rtas_data_buf_lock);
53EXPORT_SYMBOL(rtas_data_buf_lock);
54
55char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
56EXPORT_SYMBOL(rtas_data_buf);
57
58unsigned long rtas_rmo_buf;
59
60/*
61 * If non-NULL, this gets called when the kernel terminates.
62 * This is done like this so rtas_flash can be a module.
63 */
64void (*rtas_flash_term_hook)(int);
65EXPORT_SYMBOL(rtas_flash_term_hook);
66
67/* RTAS use home made raw locking instead of spin_lock_irqsave
68 * because those can be called from within really nasty contexts
69 * such as having the timebase stopped which would lockup with
70 * normal locks and spinlock debugging enabled
71 */
72static unsigned long lock_rtas(void)
73{
74 unsigned long flags;
75
76 local_irq_save(flags);
77 preempt_disable();
78 arch_spin_lock_flags(&rtas.lock, flags);
79 return flags;
80}
81
82static void unlock_rtas(unsigned long flags)
83{
84 arch_spin_unlock(&rtas.lock);
85 local_irq_restore(flags);
86 preempt_enable();
87}
88
89/*
90 * call_rtas_display_status and call_rtas_display_status_delay
91 * are designed only for very early low-level debugging, which
92 * is why the token is hard-coded to 10.
93 */
94static void call_rtas_display_status(unsigned char c)
95{
96 struct rtas_args *args = &rtas.args;
97 unsigned long s;
98
99 if (!rtas.base)
100 return;
101 s = lock_rtas();
102
103 args->token = cpu_to_be32(10);
104 args->nargs = cpu_to_be32(1);
105 args->nret = cpu_to_be32(1);
106 args->rets = &(args->args[1]);
107 args->args[0] = cpu_to_be32(c);
108
109 enter_rtas(__pa(args));
110
111 unlock_rtas(s);
112}
113
114static void call_rtas_display_status_delay(char c)
115{
116 static int pending_newline = 0; /* did last write end with unprinted newline? */
117 static int width = 16;
118
119 if (c == '\n') {
120 while (width-- > 0)
121 call_rtas_display_status(' ');
122 width = 16;
123 mdelay(500);
124 pending_newline = 1;
125 } else {
126 if (pending_newline) {
127 call_rtas_display_status('\r');
128 call_rtas_display_status('\n');
129 }
130 pending_newline = 0;
131 if (width--) {
132 call_rtas_display_status(c);
133 udelay(10000);
134 }
135 }
136}
137
138void __init udbg_init_rtas_panel(void)
139{
140 udbg_putc = call_rtas_display_status_delay;
141}
142
143#ifdef CONFIG_UDBG_RTAS_CONSOLE
144
145/* If you think you're dying before early_init_dt_scan_rtas() does its
146 * work, you can hard code the token values for your firmware here and
147 * hardcode rtas.base/entry etc.
148 */
149static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
150static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
151
152static void udbg_rtascon_putc(char c)
153{
154 int tries;
155
156 if (!rtas.base)
157 return;
158
159 /* Add CRs before LFs */
160 if (c == '\n')
161 udbg_rtascon_putc('\r');
162
163 /* if there is more than one character to be displayed, wait a bit */
164 for (tries = 0; tries < 16; tries++) {
165 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
166 break;
167 udelay(1000);
168 }
169}
170
171static int udbg_rtascon_getc_poll(void)
172{
173 int c;
174
175 if (!rtas.base)
176 return -1;
177
178 if (rtas_call(rtas_getchar_token, 0, 2, &c))
179 return -1;
180
181 return c;
182}
183
184static int udbg_rtascon_getc(void)
185{
186 int c;
187
188 while ((c = udbg_rtascon_getc_poll()) == -1)
189 ;
190
191 return c;
192}
193
194
195void __init udbg_init_rtas_console(void)
196{
197 udbg_putc = udbg_rtascon_putc;
198 udbg_getc = udbg_rtascon_getc;
199 udbg_getc_poll = udbg_rtascon_getc_poll;
200}
201#endif /* CONFIG_UDBG_RTAS_CONSOLE */
202
203void rtas_progress(char *s, unsigned short hex)
204{
205 struct device_node *root;
206 int width;
207 const __be32 *p;
208 char *os;
209 static int display_character, set_indicator;
210 static int display_width, display_lines, form_feed;
211 static const int *row_width;
212 static DEFINE_SPINLOCK(progress_lock);
213 static int current_line;
214 static int pending_newline = 0; /* did last write end with unprinted newline? */
215
216 if (!rtas.base)
217 return;
218
219 if (display_width == 0) {
220 display_width = 0x10;
221 if ((root = of_find_node_by_path("/rtas"))) {
222 if ((p = of_get_property(root,
223 "ibm,display-line-length", NULL)))
224 display_width = be32_to_cpu(*p);
225 if ((p = of_get_property(root,
226 "ibm,form-feed", NULL)))
227 form_feed = be32_to_cpu(*p);
228 if ((p = of_get_property(root,
229 "ibm,display-number-of-lines", NULL)))
230 display_lines = be32_to_cpu(*p);
231 row_width = of_get_property(root,
232 "ibm,display-truncation-length", NULL);
233 of_node_put(root);
234 }
235 display_character = rtas_token("display-character");
236 set_indicator = rtas_token("set-indicator");
237 }
238
239 if (display_character == RTAS_UNKNOWN_SERVICE) {
240 /* use hex display if available */
241 if (set_indicator != RTAS_UNKNOWN_SERVICE)
242 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
243 return;
244 }
245
246 spin_lock(&progress_lock);
247
248 /*
249 * Last write ended with newline, but we didn't print it since
250 * it would just clear the bottom line of output. Print it now
251 * instead.
252 *
253 * If no newline is pending and form feed is supported, clear the
254 * display with a form feed; otherwise, print a CR to start output
255 * at the beginning of the line.
256 */
257 if (pending_newline) {
258 rtas_call(display_character, 1, 1, NULL, '\r');
259 rtas_call(display_character, 1, 1, NULL, '\n');
260 pending_newline = 0;
261 } else {
262 current_line = 0;
263 if (form_feed)
264 rtas_call(display_character, 1, 1, NULL,
265 (char)form_feed);
266 else
267 rtas_call(display_character, 1, 1, NULL, '\r');
268 }
269
270 if (row_width)
271 width = row_width[current_line];
272 else
273 width = display_width;
274 os = s;
275 while (*os) {
276 if (*os == '\n' || *os == '\r') {
277 /* If newline is the last character, save it
278 * until next call to avoid bumping up the
279 * display output.
280 */
281 if (*os == '\n' && !os[1]) {
282 pending_newline = 1;
283 current_line++;
284 if (current_line > display_lines-1)
285 current_line = display_lines-1;
286 spin_unlock(&progress_lock);
287 return;
288 }
289
290 /* RTAS wants CR-LF, not just LF */
291
292 if (*os == '\n') {
293 rtas_call(display_character, 1, 1, NULL, '\r');
294 rtas_call(display_character, 1, 1, NULL, '\n');
295 } else {
296 /* CR might be used to re-draw a line, so we'll
297 * leave it alone and not add LF.
298 */
299 rtas_call(display_character, 1, 1, NULL, *os);
300 }
301
302 if (row_width)
303 width = row_width[current_line];
304 else
305 width = display_width;
306 } else {
307 width--;
308 rtas_call(display_character, 1, 1, NULL, *os);
309 }
310
311 os++;
312
313 /* if we overwrite the screen length */
314 if (width <= 0)
315 while ((*os != 0) && (*os != '\n') && (*os != '\r'))
316 os++;
317 }
318
319 spin_unlock(&progress_lock);
320}
321EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */
322
323int rtas_token(const char *service)
324{
325 const __be32 *tokp;
326 if (rtas.dev == NULL)
327 return RTAS_UNKNOWN_SERVICE;
328 tokp = of_get_property(rtas.dev, service, NULL);
329 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
330}
331EXPORT_SYMBOL(rtas_token);
332
333int rtas_service_present(const char *service)
334{
335 return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
336}
337EXPORT_SYMBOL(rtas_service_present);
338
339#ifdef CONFIG_RTAS_ERROR_LOGGING
340/*
341 * Return the firmware-specified size of the error log buffer
342 * for all rtas calls that require an error buffer argument.
343 * This includes 'check-exception' and 'rtas-last-error'.
344 */
345int rtas_get_error_log_max(void)
346{
347 static int rtas_error_log_max;
348 if (rtas_error_log_max)
349 return rtas_error_log_max;
350
351 rtas_error_log_max = rtas_token ("rtas-error-log-max");
352 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
353 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
354 printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
355 rtas_error_log_max);
356 rtas_error_log_max = RTAS_ERROR_LOG_MAX;
357 }
358 return rtas_error_log_max;
359}
360EXPORT_SYMBOL(rtas_get_error_log_max);
361
362
363static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
364static int rtas_last_error_token;
365
366/** Return a copy of the detailed error text associated with the
367 * most recent failed call to rtas. Because the error text
368 * might go stale if there are any other intervening rtas calls,
369 * this routine must be called atomically with whatever produced
370 * the error (i.e. with rtas.lock still held from the previous call).
371 */
372static char *__fetch_rtas_last_error(char *altbuf)
373{
374 struct rtas_args err_args, save_args;
375 u32 bufsz;
376 char *buf = NULL;
377
378 if (rtas_last_error_token == -1)
379 return NULL;
380
381 bufsz = rtas_get_error_log_max();
382
383 err_args.token = cpu_to_be32(rtas_last_error_token);
384 err_args.nargs = cpu_to_be32(2);
385 err_args.nret = cpu_to_be32(1);
386 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
387 err_args.args[1] = cpu_to_be32(bufsz);
388 err_args.args[2] = 0;
389
390 save_args = rtas.args;
391 rtas.args = err_args;
392
393 enter_rtas(__pa(&rtas.args));
394
395 err_args = rtas.args;
396 rtas.args = save_args;
397
398 /* Log the error in the unlikely case that there was one. */
399 if (unlikely(err_args.args[2] == 0)) {
400 if (altbuf) {
401 buf = altbuf;
402 } else {
403 buf = rtas_err_buf;
404 if (mem_init_done)
405 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
406 }
407 if (buf)
408 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
409 }
410
411 return buf;
412}
413
414#define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
415
416#else /* CONFIG_RTAS_ERROR_LOGGING */
417#define __fetch_rtas_last_error(x) NULL
418#define get_errorlog_buffer() NULL
419#endif
420
421int rtas_call(int token, int nargs, int nret, int *outputs, ...)
422{
423 va_list list;
424 int i;
425 unsigned long s;
426 struct rtas_args *rtas_args;
427 char *buff_copy = NULL;
428 int ret;
429
430 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
431 return -1;
432
433 s = lock_rtas();
434 rtas_args = &rtas.args;
435
436 rtas_args->token = cpu_to_be32(token);
437 rtas_args->nargs = cpu_to_be32(nargs);
438 rtas_args->nret = cpu_to_be32(nret);
439 rtas_args->rets = &(rtas_args->args[nargs]);
440 va_start(list, outputs);
441 for (i = 0; i < nargs; ++i)
442 rtas_args->args[i] = cpu_to_be32(va_arg(list, __u32));
443 va_end(list);
444
445 for (i = 0; i < nret; ++i)
446 rtas_args->rets[i] = 0;
447
448 enter_rtas(__pa(rtas_args));
449
450 /* A -1 return code indicates that the last command couldn't
451 be completed due to a hardware error. */
452 if (be32_to_cpu(rtas_args->rets[0]) == -1)
453 buff_copy = __fetch_rtas_last_error(NULL);
454
455 if (nret > 1 && outputs != NULL)
456 for (i = 0; i < nret-1; ++i)
457 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
458 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
459
460 unlock_rtas(s);
461
462 if (buff_copy) {
463 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
464 if (mem_init_done)
465 kfree(buff_copy);
466 }
467 return ret;
468}
469EXPORT_SYMBOL(rtas_call);
470
471/* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status
472 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
473 */
474unsigned int rtas_busy_delay_time(int status)
475{
476 int order;
477 unsigned int ms = 0;
478
479 if (status == RTAS_BUSY) {
480 ms = 1;
481 } else if (status >= 9900 && status <= 9905) {
482 order = status - 9900;
483 for (ms = 1; order > 0; order--)
484 ms *= 10;
485 }
486
487 return ms;
488}
489EXPORT_SYMBOL(rtas_busy_delay_time);
490
491/* For an RTAS busy status code, perform the hinted delay. */
492unsigned int rtas_busy_delay(int status)
493{
494 unsigned int ms;
495
496 might_sleep();
497 ms = rtas_busy_delay_time(status);
498 if (ms && need_resched())
499 msleep(ms);
500
501 return ms;
502}
503EXPORT_SYMBOL(rtas_busy_delay);
504
505static int rtas_error_rc(int rtas_rc)
506{
507 int rc;
508
509 switch (rtas_rc) {
510 case -1: /* Hardware Error */
511 rc = -EIO;
512 break;
513 case -3: /* Bad indicator/domain/etc */
514 rc = -EINVAL;
515 break;
516 case -9000: /* Isolation error */
517 rc = -EFAULT;
518 break;
519 case -9001: /* Outstanding TCE/PTE */
520 rc = -EEXIST;
521 break;
522 case -9002: /* No usable slot */
523 rc = -ENODEV;
524 break;
525 default:
526 printk(KERN_ERR "%s: unexpected RTAS error %d\n",
527 __func__, rtas_rc);
528 rc = -ERANGE;
529 break;
530 }
531 return rc;
532}
533
534int rtas_get_power_level(int powerdomain, int *level)
535{
536 int token = rtas_token("get-power-level");
537 int rc;
538
539 if (token == RTAS_UNKNOWN_SERVICE)
540 return -ENOENT;
541
542 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
543 udelay(1);
544
545 if (rc < 0)
546 return rtas_error_rc(rc);
547 return rc;
548}
549EXPORT_SYMBOL(rtas_get_power_level);
550
551int rtas_set_power_level(int powerdomain, int level, int *setlevel)
552{
553 int token = rtas_token("set-power-level");
554 int rc;
555
556 if (token == RTAS_UNKNOWN_SERVICE)
557 return -ENOENT;
558
559 do {
560 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
561 } while (rtas_busy_delay(rc));
562
563 if (rc < 0)
564 return rtas_error_rc(rc);
565 return rc;
566}
567EXPORT_SYMBOL(rtas_set_power_level);
568
569int rtas_get_sensor(int sensor, int index, int *state)
570{
571 int token = rtas_token("get-sensor-state");
572 int rc;
573
574 if (token == RTAS_UNKNOWN_SERVICE)
575 return -ENOENT;
576
577 do {
578 rc = rtas_call(token, 2, 2, state, sensor, index);
579 } while (rtas_busy_delay(rc));
580
581 if (rc < 0)
582 return rtas_error_rc(rc);
583 return rc;
584}
585EXPORT_SYMBOL(rtas_get_sensor);
586
587bool rtas_indicator_present(int token, int *maxindex)
588{
589 int proplen, count, i;
590 const struct indicator_elem {
591 __be32 token;
592 __be32 maxindex;
593 } *indicators;
594
595 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
596 if (!indicators)
597 return false;
598
599 count = proplen / sizeof(struct indicator_elem);
600
601 for (i = 0; i < count; i++) {
602 if (__be32_to_cpu(indicators[i].token) != token)
603 continue;
604 if (maxindex)
605 *maxindex = __be32_to_cpu(indicators[i].maxindex);
606 return true;
607 }
608
609 return false;
610}
611EXPORT_SYMBOL(rtas_indicator_present);
612
613int rtas_set_indicator(int indicator, int index, int new_value)
614{
615 int token = rtas_token("set-indicator");
616 int rc;
617
618 if (token == RTAS_UNKNOWN_SERVICE)
619 return -ENOENT;
620
621 do {
622 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
623 } while (rtas_busy_delay(rc));
624
625 if (rc < 0)
626 return rtas_error_rc(rc);
627 return rc;
628}
629EXPORT_SYMBOL(rtas_set_indicator);
630
631/*
632 * Ignoring RTAS extended delay
633 */
634int rtas_set_indicator_fast(int indicator, int index, int new_value)
635{
636 int rc;
637 int token = rtas_token("set-indicator");
638
639 if (token == RTAS_UNKNOWN_SERVICE)
640 return -ENOENT;
641
642 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
643
644 WARN_ON(rc == -2 || (rc >= 9900 && rc <= 9905));
645
646 if (rc < 0)
647 return rtas_error_rc(rc);
648
649 return rc;
650}
651
652void rtas_restart(char *cmd)
653{
654 if (rtas_flash_term_hook)
655 rtas_flash_term_hook(SYS_RESTART);
656 printk("RTAS system-reboot returned %d\n",
657 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
658 for (;;);
659}
660
661void rtas_power_off(void)
662{
663 if (rtas_flash_term_hook)
664 rtas_flash_term_hook(SYS_POWER_OFF);
665 /* allow power on only with power button press */
666 printk("RTAS power-off returned %d\n",
667 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
668 for (;;);
669}
670
671void rtas_halt(void)
672{
673 if (rtas_flash_term_hook)
674 rtas_flash_term_hook(SYS_HALT);
675 /* allow power on only with power button press */
676 printk("RTAS power-off returned %d\n",
677 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
678 for (;;);
679}
680
681/* Must be in the RMO region, so we place it here */
682static char rtas_os_term_buf[2048];
683
684void rtas_os_term(char *str)
685{
686 int status;
687
688 /*
689 * Firmware with the ibm,extended-os-term property is guaranteed
690 * to always return from an ibm,os-term call. Earlier versions without
691 * this property may terminate the partition which we want to avoid
692 * since it interferes with panic_timeout.
693 */
694 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
695 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
696 return;
697
698 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
699
700 do {
701 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
702 __pa(rtas_os_term_buf));
703 } while (rtas_busy_delay(status));
704
705 if (status != 0)
706 printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
707}
708
709static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
710#ifdef CONFIG_PPC_PSERIES
711static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
712{
713 u16 slb_size = mmu_slb_size;
714 int rc = H_MULTI_THREADS_ACTIVE;
715 int cpu;
716
717 slb_set_size(SLB_MIN_SIZE);
718 printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id());
719
720 while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) &&
721 !atomic_read(&data->error))
722 rc = rtas_call(data->token, 0, 1, NULL);
723
724 if (rc || atomic_read(&data->error)) {
725 printk(KERN_DEBUG "ibm,suspend-me returned %d\n", rc);
726 slb_set_size(slb_size);
727 }
728
729 if (atomic_read(&data->error))
730 rc = atomic_read(&data->error);
731
732 atomic_set(&data->error, rc);
733 pSeries_coalesce_init();
734
735 if (wake_when_done) {
736 atomic_set(&data->done, 1);
737
738 for_each_online_cpu(cpu)
739 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
740 }
741
742 if (atomic_dec_return(&data->working) == 0)
743 complete(data->complete);
744
745 return rc;
746}
747
748int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data)
749{
750 atomic_inc(&data->working);
751 return __rtas_suspend_last_cpu(data, 0);
752}
753
754static int __rtas_suspend_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
755{
756 long rc = H_SUCCESS;
757 unsigned long msr_save;
758 int cpu;
759
760 atomic_inc(&data->working);
761
762 /* really need to ensure MSR.EE is off for H_JOIN */
763 msr_save = mfmsr();
764 mtmsr(msr_save & ~(MSR_EE));
765
766 while (rc == H_SUCCESS && !atomic_read(&data->done) && !atomic_read(&data->error))
767 rc = plpar_hcall_norets(H_JOIN);
768
769 mtmsr(msr_save);
770
771 if (rc == H_SUCCESS) {
772 /* This cpu was prodded and the suspend is complete. */
773 goto out;
774 } else if (rc == H_CONTINUE) {
775 /* All other cpus are in H_JOIN, this cpu does
776 * the suspend.
777 */
778 return __rtas_suspend_last_cpu(data, wake_when_done);
779 } else {
780 printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
781 smp_processor_id(), rc);
782 atomic_set(&data->error, rc);
783 }
784
785 if (wake_when_done) {
786 atomic_set(&data->done, 1);
787
788 /* This cpu did the suspend or got an error; in either case,
789 * we need to prod all other other cpus out of join state.
790 * Extra prods are harmless.
791 */
792 for_each_online_cpu(cpu)
793 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
794 }
795out:
796 if (atomic_dec_return(&data->working) == 0)
797 complete(data->complete);
798 return rc;
799}
800
801int rtas_suspend_cpu(struct rtas_suspend_me_data *data)
802{
803 return __rtas_suspend_cpu(data, 0);
804}
805
806static void rtas_percpu_suspend_me(void *info)
807{
808 __rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
809}
810
811enum rtas_cpu_state {
812 DOWN,
813 UP,
814};
815
816#ifndef CONFIG_SMP
817static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
818 cpumask_var_t cpus)
819{
820 if (!cpumask_empty(cpus)) {
821 cpumask_clear(cpus);
822 return -EINVAL;
823 } else
824 return 0;
825}
826#else
827/* On return cpumask will be altered to indicate CPUs changed.
828 * CPUs with states changed will be set in the mask,
829 * CPUs with status unchanged will be unset in the mask. */
830static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
831 cpumask_var_t cpus)
832{
833 int cpu;
834 int cpuret = 0;
835 int ret = 0;
836
837 if (cpumask_empty(cpus))
838 return 0;
839
840 for_each_cpu(cpu, cpus) {
841 switch (state) {
842 case DOWN:
843 cpuret = cpu_down(cpu);
844 break;
845 case UP:
846 cpuret = cpu_up(cpu);
847 break;
848 }
849 if (cpuret) {
850 pr_debug("%s: cpu_%s for cpu#%d returned %d.\n",
851 __func__,
852 ((state == UP) ? "up" : "down"),
853 cpu, cpuret);
854 if (!ret)
855 ret = cpuret;
856 if (state == UP) {
857 /* clear bits for unchanged cpus, return */
858 cpumask_shift_right(cpus, cpus, cpu);
859 cpumask_shift_left(cpus, cpus, cpu);
860 break;
861 } else {
862 /* clear bit for unchanged cpu, continue */
863 cpumask_clear_cpu(cpu, cpus);
864 }
865 }
866 }
867
868 return ret;
869}
870#endif
871
872int rtas_online_cpus_mask(cpumask_var_t cpus)
873{
874 int ret;
875
876 ret = rtas_cpu_state_change_mask(UP, cpus);
877
878 if (ret) {
879 cpumask_var_t tmp_mask;
880
881 if (!alloc_cpumask_var(&tmp_mask, GFP_TEMPORARY))
882 return ret;
883
884 /* Use tmp_mask to preserve cpus mask from first failure */
885 cpumask_copy(tmp_mask, cpus);
886 rtas_offline_cpus_mask(tmp_mask);
887 free_cpumask_var(tmp_mask);
888 }
889
890 return ret;
891}
892EXPORT_SYMBOL(rtas_online_cpus_mask);
893
894int rtas_offline_cpus_mask(cpumask_var_t cpus)
895{
896 return rtas_cpu_state_change_mask(DOWN, cpus);
897}
898EXPORT_SYMBOL(rtas_offline_cpus_mask);
899
900int rtas_ibm_suspend_me(struct rtas_args *args)
901{
902 long state;
903 long rc;
904 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
905 struct rtas_suspend_me_data data;
906 DECLARE_COMPLETION_ONSTACK(done);
907 cpumask_var_t offline_mask;
908 int cpuret;
909
910 if (!rtas_service_present("ibm,suspend-me"))
911 return -ENOSYS;
912
913 /* Make sure the state is valid */
914 rc = plpar_hcall(H_VASI_STATE, retbuf,
915 ((u64)args->args[0] << 32) | args->args[1]);
916
917 state = retbuf[0];
918
919 if (rc) {
920 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
921 return rc;
922 } else if (state == H_VASI_ENABLED) {
923 args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
924 return 0;
925 } else if (state != H_VASI_SUSPENDING) {
926 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
927 state);
928 args->args[args->nargs] = -1;
929 return 0;
930 }
931
932 if (!alloc_cpumask_var(&offline_mask, GFP_TEMPORARY))
933 return -ENOMEM;
934
935 atomic_set(&data.working, 0);
936 atomic_set(&data.done, 0);
937 atomic_set(&data.error, 0);
938 data.token = rtas_token("ibm,suspend-me");
939 data.complete = &done;
940
941 /* All present CPUs must be online */
942 cpumask_andnot(offline_mask, cpu_present_mask, cpu_online_mask);
943 cpuret = rtas_online_cpus_mask(offline_mask);
944 if (cpuret) {
945 pr_err("%s: Could not bring present CPUs online.\n", __func__);
946 atomic_set(&data.error, cpuret);
947 goto out;
948 }
949
950 stop_topology_update();
951
952 /* Call function on all CPUs. One of us will make the
953 * rtas call
954 */
955 if (on_each_cpu(rtas_percpu_suspend_me, &data, 0))
956 atomic_set(&data.error, -EINVAL);
957
958 wait_for_completion(&done);
959
960 if (atomic_read(&data.error) != 0)
961 printk(KERN_ERR "Error doing global join\n");
962
963 start_topology_update();
964
965 /* Take down CPUs not online prior to suspend */
966 cpuret = rtas_offline_cpus_mask(offline_mask);
967 if (cpuret)
968 pr_warn("%s: Could not restore CPUs to offline state.\n",
969 __func__);
970
971out:
972 free_cpumask_var(offline_mask);
973 return atomic_read(&data.error);
974}
975#else /* CONFIG_PPC_PSERIES */
976int rtas_ibm_suspend_me(struct rtas_args *args)
977{
978 return -ENOSYS;
979}
980#endif
981
982/**
983 * Find a specific pseries error log in an RTAS extended event log.
984 * @log: RTAS error/event log
985 * @section_id: two character section identifier
986 *
987 * Returns a pointer to the specified errorlog or NULL if not found.
988 */
989struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
990 uint16_t section_id)
991{
992 struct rtas_ext_event_log_v6 *ext_log =
993 (struct rtas_ext_event_log_v6 *)log->buffer;
994 struct pseries_errorlog *sect;
995 unsigned char *p, *log_end;
996 uint32_t ext_log_length = rtas_error_extended_log_length(log);
997 uint8_t log_format = rtas_ext_event_log_format(ext_log);
998 uint32_t company_id = rtas_ext_event_company_id(ext_log);
999
1000 /* Check that we understand the format */
1001 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
1002 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
1003 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
1004 return NULL;
1005
1006 log_end = log->buffer + ext_log_length;
1007 p = ext_log->vendor_log;
1008
1009 while (p < log_end) {
1010 sect = (struct pseries_errorlog *)p;
1011 if (pseries_errorlog_id(sect) == section_id)
1012 return sect;
1013 p += pseries_errorlog_length(sect);
1014 }
1015
1016 return NULL;
1017}
1018
1019/* We assume to be passed big endian arguments */
1020asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
1021{
1022 struct rtas_args args;
1023 unsigned long flags;
1024 char *buff_copy, *errbuf = NULL;
1025 int nargs, nret, token;
1026 int rc;
1027
1028 if (!capable(CAP_SYS_ADMIN))
1029 return -EPERM;
1030
1031 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1032 return -EFAULT;
1033
1034 nargs = be32_to_cpu(args.nargs);
1035 nret = be32_to_cpu(args.nret);
1036 token = be32_to_cpu(args.token);
1037
1038 if (nargs > ARRAY_SIZE(args.args)
1039 || nret > ARRAY_SIZE(args.args)
1040 || nargs + nret > ARRAY_SIZE(args.args))
1041 return -EINVAL;
1042
1043 /* Copy in args. */
1044 if (copy_from_user(args.args, uargs->args,
1045 nargs * sizeof(rtas_arg_t)) != 0)
1046 return -EFAULT;
1047
1048 if (token == RTAS_UNKNOWN_SERVICE)
1049 return -EINVAL;
1050
1051 args.rets = &args.args[nargs];
1052 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1053
1054 /* Need to handle ibm,suspend_me call specially */
1055 if (token == ibm_suspend_me_token) {
1056 rc = rtas_ibm_suspend_me(&args);
1057 if (rc)
1058 return rc;
1059 goto copy_return;
1060 }
1061
1062 buff_copy = get_errorlog_buffer();
1063
1064 flags = lock_rtas();
1065
1066 rtas.args = args;
1067 enter_rtas(__pa(&rtas.args));
1068 args = rtas.args;
1069
1070 /* A -1 return code indicates that the last command couldn't
1071 be completed due to a hardware error. */
1072 if (be32_to_cpu(args.rets[0]) == -1)
1073 errbuf = __fetch_rtas_last_error(buff_copy);
1074
1075 unlock_rtas(flags);
1076
1077 if (buff_copy) {
1078 if (errbuf)
1079 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1080 kfree(buff_copy);
1081 }
1082
1083 copy_return:
1084 /* Copy out args. */
1085 if (copy_to_user(uargs->args + nargs,
1086 args.args + nargs,
1087 nret * sizeof(rtas_arg_t)) != 0)
1088 return -EFAULT;
1089
1090 return 0;
1091}
1092
1093/*
1094 * Call early during boot, before mem init or bootmem, to retrieve the RTAS
1095 * informations from the device-tree and allocate the RMO buffer for userland
1096 * accesses.
1097 */
1098void __init rtas_initialize(void)
1099{
1100 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1101
1102 /* Get RTAS dev node and fill up our "rtas" structure with infos
1103 * about it.
1104 */
1105 rtas.dev = of_find_node_by_name(NULL, "rtas");
1106 if (rtas.dev) {
1107 const __be32 *basep, *entryp, *sizep;
1108
1109 basep = of_get_property(rtas.dev, "linux,rtas-base", NULL);
1110 sizep = of_get_property(rtas.dev, "rtas-size", NULL);
1111 if (basep != NULL && sizep != NULL) {
1112 rtas.base = __be32_to_cpu(*basep);
1113 rtas.size = __be32_to_cpu(*sizep);
1114 entryp = of_get_property(rtas.dev,
1115 "linux,rtas-entry", NULL);
1116 if (entryp == NULL) /* Ugh */
1117 rtas.entry = rtas.base;
1118 else
1119 rtas.entry = __be32_to_cpu(*entryp);
1120 } else
1121 rtas.dev = NULL;
1122 }
1123 if (!rtas.dev)
1124 return;
1125
1126 /* If RTAS was found, allocate the RMO buffer for it and look for
1127 * the stop-self token if any
1128 */
1129#ifdef CONFIG_PPC64
1130 if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR)) {
1131 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1132 ibm_suspend_me_token = rtas_token("ibm,suspend-me");
1133 }
1134#endif
1135 rtas_rmo_buf = memblock_alloc_base(RTAS_RMOBUF_MAX, PAGE_SIZE, rtas_region);
1136
1137#ifdef CONFIG_RTAS_ERROR_LOGGING
1138 rtas_last_error_token = rtas_token("rtas-last-error");
1139#endif
1140}
1141
1142int __init early_init_dt_scan_rtas(unsigned long node,
1143 const char *uname, int depth, void *data)
1144{
1145 u32 *basep, *entryp, *sizep;
1146
1147 if (depth != 1 || strcmp(uname, "rtas") != 0)
1148 return 0;
1149
1150 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1151 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1152 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1153
1154 if (basep && entryp && sizep) {
1155 rtas.base = *basep;
1156 rtas.entry = *entryp;
1157 rtas.size = *sizep;
1158 }
1159
1160#ifdef CONFIG_UDBG_RTAS_CONSOLE
1161 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1162 if (basep)
1163 rtas_putchar_token = *basep;
1164
1165 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1166 if (basep)
1167 rtas_getchar_token = *basep;
1168
1169 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1170 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1171 udbg_init_rtas_console();
1172
1173#endif
1174
1175 /* break now */
1176 return 1;
1177}
1178
1179static arch_spinlock_t timebase_lock;
1180static u64 timebase = 0;
1181
1182void rtas_give_timebase(void)
1183{
1184 unsigned long flags;
1185
1186 local_irq_save(flags);
1187 hard_irq_disable();
1188 arch_spin_lock(&timebase_lock);
1189 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1190 timebase = get_tb();
1191 arch_spin_unlock(&timebase_lock);
1192
1193 while (timebase)
1194 barrier();
1195 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1196 local_irq_restore(flags);
1197}
1198
1199void rtas_take_timebase(void)
1200{
1201 while (!timebase)
1202 barrier();
1203 arch_spin_lock(&timebase_lock);
1204 set_tb(timebase >> 32, timebase & 0xffffffff);
1205 timebase = 0;
1206 arch_spin_unlock(&timebase_lock);
1207}