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 #include <stdarg.h>
11 #include <linux/kernel.h>
12 #include <linux/types.h>
13 #include <linux/spinlock.h>
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/capability.h>
17 #include <linux/delay.h>
18 #include <linux/cpu.h>
19 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/completion.h>
22 #include <linux/cpumask.h>
23 #include <linux/memblock.h>
24 #include <linux/slab.h>
25 #include <linux/reboot.h>
26 #include <linux/syscalls.h>
27
28 #include <asm/prom.h>
29 #include <asm/rtas.h>
30 #include <asm/hvcall.h>
31 #include <asm/machdep.h>
32 #include <asm/firmware.h>
33 #include <asm/page.h>
34 #include <asm/param.h>
35 #include <asm/delay.h>
36 #include <linux/uaccess.h>
37 #include <asm/udbg.h>
38 #include <asm/syscalls.h>
39 #include <asm/smp.h>
40 #include <linux/atomic.h>
41 #include <asm/time.h>
42 #include <asm/mmu.h>
43 #include <asm/topology.h>
44 #include <asm/paca.h>
45
46 /* This is here deliberately so it's only used in this file */
47 void enter_rtas(unsigned long);
48
49 struct rtas_t rtas = {
50 .lock = __ARCH_SPIN_LOCK_UNLOCKED
51 };
52 EXPORT_SYMBOL(rtas);
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 /* RTAS use home made raw locking instead of spin_lock_irqsave
70 * because those can be called from within really nasty contexts
71 * such as having the timebase stopped which would lockup with
72 * normal locks and spinlock debugging enabled
73 */
lock_rtas(void)74 static unsigned long lock_rtas(void)
75 {
76 unsigned long flags;
77
78 local_irq_save(flags);
79 preempt_disable();
80 arch_spin_lock(&rtas.lock);
81 return flags;
82 }
83
unlock_rtas(unsigned long flags)84 static void unlock_rtas(unsigned long flags)
85 {
86 arch_spin_unlock(&rtas.lock);
87 local_irq_restore(flags);
88 preempt_enable();
89 }
90
91 /*
92 * call_rtas_display_status and call_rtas_display_status_delay
93 * are designed only for very early low-level debugging, which
94 * is why the token is hard-coded to 10.
95 */
call_rtas_display_status(unsigned char c)96 static void call_rtas_display_status(unsigned char c)
97 {
98 unsigned long s;
99
100 if (!rtas.base)
101 return;
102
103 s = lock_rtas();
104 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c);
105 unlock_rtas(s);
106 }
107
call_rtas_display_status_delay(char c)108 static void call_rtas_display_status_delay(char c)
109 {
110 static int pending_newline = 0; /* did last write end with unprinted newline? */
111 static int width = 16;
112
113 if (c == '\n') {
114 while (width-- > 0)
115 call_rtas_display_status(' ');
116 width = 16;
117 mdelay(500);
118 pending_newline = 1;
119 } else {
120 if (pending_newline) {
121 call_rtas_display_status('\r');
122 call_rtas_display_status('\n');
123 }
124 pending_newline = 0;
125 if (width--) {
126 call_rtas_display_status(c);
127 udelay(10000);
128 }
129 }
130 }
131
udbg_init_rtas_panel(void)132 void __init udbg_init_rtas_panel(void)
133 {
134 udbg_putc = call_rtas_display_status_delay;
135 }
136
137 #ifdef CONFIG_UDBG_RTAS_CONSOLE
138
139 /* If you think you're dying before early_init_dt_scan_rtas() does its
140 * work, you can hard code the token values for your firmware here and
141 * hardcode rtas.base/entry etc.
142 */
143 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
144 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
145
udbg_rtascon_putc(char c)146 static void udbg_rtascon_putc(char c)
147 {
148 int tries;
149
150 if (!rtas.base)
151 return;
152
153 /* Add CRs before LFs */
154 if (c == '\n')
155 udbg_rtascon_putc('\r');
156
157 /* if there is more than one character to be displayed, wait a bit */
158 for (tries = 0; tries < 16; tries++) {
159 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
160 break;
161 udelay(1000);
162 }
163 }
164
udbg_rtascon_getc_poll(void)165 static int udbg_rtascon_getc_poll(void)
166 {
167 int c;
168
169 if (!rtas.base)
170 return -1;
171
172 if (rtas_call(rtas_getchar_token, 0, 2, &c))
173 return -1;
174
175 return c;
176 }
177
udbg_rtascon_getc(void)178 static int udbg_rtascon_getc(void)
179 {
180 int c;
181
182 while ((c = udbg_rtascon_getc_poll()) == -1)
183 ;
184
185 return c;
186 }
187
188
udbg_init_rtas_console(void)189 void __init udbg_init_rtas_console(void)
190 {
191 udbg_putc = udbg_rtascon_putc;
192 udbg_getc = udbg_rtascon_getc;
193 udbg_getc_poll = udbg_rtascon_getc_poll;
194 }
195 #endif /* CONFIG_UDBG_RTAS_CONSOLE */
196
rtas_progress(char * s,unsigned short hex)197 void rtas_progress(char *s, unsigned short hex)
198 {
199 struct device_node *root;
200 int width;
201 const __be32 *p;
202 char *os;
203 static int display_character, set_indicator;
204 static int display_width, display_lines, form_feed;
205 static const int *row_width;
206 static DEFINE_SPINLOCK(progress_lock);
207 static int current_line;
208 static int pending_newline = 0; /* did last write end with unprinted newline? */
209
210 if (!rtas.base)
211 return;
212
213 if (display_width == 0) {
214 display_width = 0x10;
215 if ((root = of_find_node_by_path("/rtas"))) {
216 if ((p = of_get_property(root,
217 "ibm,display-line-length", NULL)))
218 display_width = be32_to_cpu(*p);
219 if ((p = of_get_property(root,
220 "ibm,form-feed", NULL)))
221 form_feed = be32_to_cpu(*p);
222 if ((p = of_get_property(root,
223 "ibm,display-number-of-lines", NULL)))
224 display_lines = be32_to_cpu(*p);
225 row_width = of_get_property(root,
226 "ibm,display-truncation-length", NULL);
227 of_node_put(root);
228 }
229 display_character = rtas_token("display-character");
230 set_indicator = rtas_token("set-indicator");
231 }
232
233 if (display_character == RTAS_UNKNOWN_SERVICE) {
234 /* use hex display if available */
235 if (set_indicator != RTAS_UNKNOWN_SERVICE)
236 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
237 return;
238 }
239
240 spin_lock(&progress_lock);
241
242 /*
243 * Last write ended with newline, but we didn't print it since
244 * it would just clear the bottom line of output. Print it now
245 * instead.
246 *
247 * If no newline is pending and form feed is supported, clear the
248 * display with a form feed; otherwise, print a CR to start output
249 * at the beginning of the line.
250 */
251 if (pending_newline) {
252 rtas_call(display_character, 1, 1, NULL, '\r');
253 rtas_call(display_character, 1, 1, NULL, '\n');
254 pending_newline = 0;
255 } else {
256 current_line = 0;
257 if (form_feed)
258 rtas_call(display_character, 1, 1, NULL,
259 (char)form_feed);
260 else
261 rtas_call(display_character, 1, 1, NULL, '\r');
262 }
263
264 if (row_width)
265 width = row_width[current_line];
266 else
267 width = display_width;
268 os = s;
269 while (*os) {
270 if (*os == '\n' || *os == '\r') {
271 /* If newline is the last character, save it
272 * until next call to avoid bumping up the
273 * display output.
274 */
275 if (*os == '\n' && !os[1]) {
276 pending_newline = 1;
277 current_line++;
278 if (current_line > display_lines-1)
279 current_line = display_lines-1;
280 spin_unlock(&progress_lock);
281 return;
282 }
283
284 /* RTAS wants CR-LF, not just LF */
285
286 if (*os == '\n') {
287 rtas_call(display_character, 1, 1, NULL, '\r');
288 rtas_call(display_character, 1, 1, NULL, '\n');
289 } else {
290 /* CR might be used to re-draw a line, so we'll
291 * leave it alone and not add LF.
292 */
293 rtas_call(display_character, 1, 1, NULL, *os);
294 }
295
296 if (row_width)
297 width = row_width[current_line];
298 else
299 width = display_width;
300 } else {
301 width--;
302 rtas_call(display_character, 1, 1, NULL, *os);
303 }
304
305 os++;
306
307 /* if we overwrite the screen length */
308 if (width <= 0)
309 while ((*os != 0) && (*os != '\n') && (*os != '\r'))
310 os++;
311 }
312
313 spin_unlock(&progress_lock);
314 }
315 EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */
316
rtas_token(const char * service)317 int rtas_token(const char *service)
318 {
319 const __be32 *tokp;
320 if (rtas.dev == NULL)
321 return RTAS_UNKNOWN_SERVICE;
322 tokp = of_get_property(rtas.dev, service, NULL);
323 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
324 }
325 EXPORT_SYMBOL(rtas_token);
326
rtas_service_present(const char * service)327 int rtas_service_present(const char *service)
328 {
329 return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
330 }
331 EXPORT_SYMBOL(rtas_service_present);
332
333 #ifdef CONFIG_RTAS_ERROR_LOGGING
334 /*
335 * Return the firmware-specified size of the error log buffer
336 * for all rtas calls that require an error buffer argument.
337 * This includes 'check-exception' and 'rtas-last-error'.
338 */
rtas_get_error_log_max(void)339 int rtas_get_error_log_max(void)
340 {
341 static int rtas_error_log_max;
342 if (rtas_error_log_max)
343 return rtas_error_log_max;
344
345 rtas_error_log_max = rtas_token ("rtas-error-log-max");
346 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
347 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
348 printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
349 rtas_error_log_max);
350 rtas_error_log_max = RTAS_ERROR_LOG_MAX;
351 }
352 return rtas_error_log_max;
353 }
354 EXPORT_SYMBOL(rtas_get_error_log_max);
355
356
357 static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
358 static int rtas_last_error_token;
359
360 /** Return a copy of the detailed error text associated with the
361 * most recent failed call to rtas. Because the error text
362 * might go stale if there are any other intervening rtas calls,
363 * this routine must be called atomically with whatever produced
364 * the error (i.e. with rtas.lock still held from the previous call).
365 */
__fetch_rtas_last_error(char * altbuf)366 static char *__fetch_rtas_last_error(char *altbuf)
367 {
368 struct rtas_args err_args, save_args;
369 u32 bufsz;
370 char *buf = NULL;
371
372 if (rtas_last_error_token == -1)
373 return NULL;
374
375 bufsz = rtas_get_error_log_max();
376
377 err_args.token = cpu_to_be32(rtas_last_error_token);
378 err_args.nargs = cpu_to_be32(2);
379 err_args.nret = cpu_to_be32(1);
380 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
381 err_args.args[1] = cpu_to_be32(bufsz);
382 err_args.args[2] = 0;
383
384 save_args = rtas.args;
385 rtas.args = err_args;
386
387 enter_rtas(__pa(&rtas.args));
388
389 err_args = rtas.args;
390 rtas.args = save_args;
391
392 /* Log the error in the unlikely case that there was one. */
393 if (unlikely(err_args.args[2] == 0)) {
394 if (altbuf) {
395 buf = altbuf;
396 } else {
397 buf = rtas_err_buf;
398 if (slab_is_available())
399 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
400 }
401 if (buf)
402 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
403 }
404
405 return buf;
406 }
407
408 #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
409
410 #else /* CONFIG_RTAS_ERROR_LOGGING */
411 #define __fetch_rtas_last_error(x) NULL
412 #define get_errorlog_buffer() NULL
413 #endif
414
415
416 static void
va_rtas_call_unlocked(struct rtas_args * args,int token,int nargs,int nret,va_list list)417 va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
418 va_list list)
419 {
420 int i;
421
422 args->token = cpu_to_be32(token);
423 args->nargs = cpu_to_be32(nargs);
424 args->nret = cpu_to_be32(nret);
425 args->rets = &(args->args[nargs]);
426
427 for (i = 0; i < nargs; ++i)
428 args->args[i] = cpu_to_be32(va_arg(list, __u32));
429
430 for (i = 0; i < nret; ++i)
431 args->rets[i] = 0;
432
433 enter_rtas(__pa(args));
434 }
435
rtas_call_unlocked(struct rtas_args * args,int token,int nargs,int nret,...)436 void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
437 {
438 va_list list;
439
440 va_start(list, nret);
441 va_rtas_call_unlocked(args, token, nargs, nret, list);
442 va_end(list);
443 }
444
rtas_call(int token,int nargs,int nret,int * outputs,...)445 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
446 {
447 va_list list;
448 int i;
449 unsigned long s;
450 struct rtas_args *rtas_args;
451 char *buff_copy = NULL;
452 int ret;
453
454 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
455 return -1;
456
457 s = lock_rtas();
458
459 /* We use the global rtas args buffer */
460 rtas_args = &rtas.args;
461
462 va_start(list, outputs);
463 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list);
464 va_end(list);
465
466 /* A -1 return code indicates that the last command couldn't
467 be completed due to a hardware error. */
468 if (be32_to_cpu(rtas_args->rets[0]) == -1)
469 buff_copy = __fetch_rtas_last_error(NULL);
470
471 if (nret > 1 && outputs != NULL)
472 for (i = 0; i < nret-1; ++i)
473 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
474 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
475
476 unlock_rtas(s);
477
478 if (buff_copy) {
479 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
480 if (slab_is_available())
481 kfree(buff_copy);
482 }
483 return ret;
484 }
485 EXPORT_SYMBOL(rtas_call);
486
487 /* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status
488 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
489 */
rtas_busy_delay_time(int status)490 unsigned int rtas_busy_delay_time(int status)
491 {
492 int order;
493 unsigned int ms = 0;
494
495 if (status == RTAS_BUSY) {
496 ms = 1;
497 } else if (status >= RTAS_EXTENDED_DELAY_MIN &&
498 status <= RTAS_EXTENDED_DELAY_MAX) {
499 order = status - RTAS_EXTENDED_DELAY_MIN;
500 for (ms = 1; order > 0; order--)
501 ms *= 10;
502 }
503
504 return ms;
505 }
506 EXPORT_SYMBOL(rtas_busy_delay_time);
507
508 /* For an RTAS busy status code, perform the hinted delay. */
rtas_busy_delay(int status)509 unsigned int rtas_busy_delay(int status)
510 {
511 unsigned int ms;
512
513 might_sleep();
514 ms = rtas_busy_delay_time(status);
515 if (ms && need_resched())
516 msleep(ms);
517
518 return ms;
519 }
520 EXPORT_SYMBOL(rtas_busy_delay);
521
rtas_error_rc(int rtas_rc)522 static int rtas_error_rc(int rtas_rc)
523 {
524 int rc;
525
526 switch (rtas_rc) {
527 case -1: /* Hardware Error */
528 rc = -EIO;
529 break;
530 case -3: /* Bad indicator/domain/etc */
531 rc = -EINVAL;
532 break;
533 case -9000: /* Isolation error */
534 rc = -EFAULT;
535 break;
536 case -9001: /* Outstanding TCE/PTE */
537 rc = -EEXIST;
538 break;
539 case -9002: /* No usable slot */
540 rc = -ENODEV;
541 break;
542 default:
543 printk(KERN_ERR "%s: unexpected RTAS error %d\n",
544 __func__, rtas_rc);
545 rc = -ERANGE;
546 break;
547 }
548 return rc;
549 }
550
rtas_get_power_level(int powerdomain,int * level)551 int rtas_get_power_level(int powerdomain, int *level)
552 {
553 int token = rtas_token("get-power-level");
554 int rc;
555
556 if (token == RTAS_UNKNOWN_SERVICE)
557 return -ENOENT;
558
559 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
560 udelay(1);
561
562 if (rc < 0)
563 return rtas_error_rc(rc);
564 return rc;
565 }
566 EXPORT_SYMBOL(rtas_get_power_level);
567
rtas_set_power_level(int powerdomain,int level,int * setlevel)568 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
569 {
570 int token = rtas_token("set-power-level");
571 int rc;
572
573 if (token == RTAS_UNKNOWN_SERVICE)
574 return -ENOENT;
575
576 do {
577 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
578 } while (rtas_busy_delay(rc));
579
580 if (rc < 0)
581 return rtas_error_rc(rc);
582 return rc;
583 }
584 EXPORT_SYMBOL(rtas_set_power_level);
585
rtas_get_sensor(int sensor,int index,int * state)586 int rtas_get_sensor(int sensor, int index, int *state)
587 {
588 int token = rtas_token("get-sensor-state");
589 int rc;
590
591 if (token == RTAS_UNKNOWN_SERVICE)
592 return -ENOENT;
593
594 do {
595 rc = rtas_call(token, 2, 2, state, sensor, index);
596 } while (rtas_busy_delay(rc));
597
598 if (rc < 0)
599 return rtas_error_rc(rc);
600 return rc;
601 }
602 EXPORT_SYMBOL(rtas_get_sensor);
603
rtas_get_sensor_fast(int sensor,int index,int * state)604 int rtas_get_sensor_fast(int sensor, int index, int *state)
605 {
606 int token = rtas_token("get-sensor-state");
607 int rc;
608
609 if (token == RTAS_UNKNOWN_SERVICE)
610 return -ENOENT;
611
612 rc = rtas_call(token, 2, 2, state, sensor, index);
613 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
614 rc <= RTAS_EXTENDED_DELAY_MAX));
615
616 if (rc < 0)
617 return rtas_error_rc(rc);
618 return rc;
619 }
620
rtas_indicator_present(int token,int * maxindex)621 bool rtas_indicator_present(int token, int *maxindex)
622 {
623 int proplen, count, i;
624 const struct indicator_elem {
625 __be32 token;
626 __be32 maxindex;
627 } *indicators;
628
629 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
630 if (!indicators)
631 return false;
632
633 count = proplen / sizeof(struct indicator_elem);
634
635 for (i = 0; i < count; i++) {
636 if (__be32_to_cpu(indicators[i].token) != token)
637 continue;
638 if (maxindex)
639 *maxindex = __be32_to_cpu(indicators[i].maxindex);
640 return true;
641 }
642
643 return false;
644 }
645 EXPORT_SYMBOL(rtas_indicator_present);
646
rtas_set_indicator(int indicator,int index,int new_value)647 int rtas_set_indicator(int indicator, int index, int new_value)
648 {
649 int token = rtas_token("set-indicator");
650 int rc;
651
652 if (token == RTAS_UNKNOWN_SERVICE)
653 return -ENOENT;
654
655 do {
656 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
657 } while (rtas_busy_delay(rc));
658
659 if (rc < 0)
660 return rtas_error_rc(rc);
661 return rc;
662 }
663 EXPORT_SYMBOL(rtas_set_indicator);
664
665 /*
666 * Ignoring RTAS extended delay
667 */
rtas_set_indicator_fast(int indicator,int index,int new_value)668 int rtas_set_indicator_fast(int indicator, int index, int new_value)
669 {
670 int rc;
671 int token = rtas_token("set-indicator");
672
673 if (token == RTAS_UNKNOWN_SERVICE)
674 return -ENOENT;
675
676 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
677
678 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
679 rc <= RTAS_EXTENDED_DELAY_MAX));
680
681 if (rc < 0)
682 return rtas_error_rc(rc);
683
684 return rc;
685 }
686
687 /**
688 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR.
689 *
690 * @fw_status: RTAS call status will be placed here if not NULL.
691 *
692 * rtas_ibm_suspend_me() should be called only on a CPU which has
693 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs
694 * should be waiting to return from H_JOIN.
695 *
696 * rtas_ibm_suspend_me() may suspend execution of the OS
697 * indefinitely. Callers should take appropriate measures upon return, such as
698 * resetting watchdog facilities.
699 *
700 * Callers may choose to retry this call if @fw_status is
701 * %RTAS_THREADS_ACTIVE.
702 *
703 * Return:
704 * 0 - The partition has resumed from suspend, possibly after
705 * migration to a different host.
706 * -ECANCELED - The operation was aborted.
707 * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call.
708 * -EBUSY - Some other condition prevented the suspend from succeeding.
709 * -EIO - Hardware/platform error.
710 */
rtas_ibm_suspend_me(int * fw_status)711 int rtas_ibm_suspend_me(int *fw_status)
712 {
713 int fwrc;
714 int ret;
715
716 fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL);
717
718 switch (fwrc) {
719 case 0:
720 ret = 0;
721 break;
722 case RTAS_SUSPEND_ABORTED:
723 ret = -ECANCELED;
724 break;
725 case RTAS_THREADS_ACTIVE:
726 ret = -EAGAIN;
727 break;
728 case RTAS_NOT_SUSPENDABLE:
729 case RTAS_OUTSTANDING_COPROC:
730 ret = -EBUSY;
731 break;
732 case -1:
733 default:
734 ret = -EIO;
735 break;
736 }
737
738 if (fw_status)
739 *fw_status = fwrc;
740
741 return ret;
742 }
743
rtas_restart(char * cmd)744 void __noreturn rtas_restart(char *cmd)
745 {
746 if (rtas_flash_term_hook)
747 rtas_flash_term_hook(SYS_RESTART);
748 printk("RTAS system-reboot returned %d\n",
749 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
750 for (;;);
751 }
752
rtas_power_off(void)753 void rtas_power_off(void)
754 {
755 if (rtas_flash_term_hook)
756 rtas_flash_term_hook(SYS_POWER_OFF);
757 /* allow power on only with power button press */
758 printk("RTAS power-off returned %d\n",
759 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
760 for (;;);
761 }
762
rtas_halt(void)763 void __noreturn rtas_halt(void)
764 {
765 if (rtas_flash_term_hook)
766 rtas_flash_term_hook(SYS_HALT);
767 /* allow power on only with power button press */
768 printk("RTAS power-off returned %d\n",
769 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
770 for (;;);
771 }
772
773 /* Must be in the RMO region, so we place it here */
774 static char rtas_os_term_buf[2048];
775
rtas_os_term(char * str)776 void rtas_os_term(char *str)
777 {
778 int status;
779
780 /*
781 * Firmware with the ibm,extended-os-term property is guaranteed
782 * to always return from an ibm,os-term call. Earlier versions without
783 * this property may terminate the partition which we want to avoid
784 * since it interferes with panic_timeout.
785 */
786 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
787 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
788 return;
789
790 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
791
792 do {
793 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
794 __pa(rtas_os_term_buf));
795 } while (rtas_busy_delay(status));
796
797 if (status != 0)
798 printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
799 }
800
801 /**
802 * rtas_activate_firmware() - Activate a new version of firmware.
803 *
804 * Activate a new version of partition firmware. The OS must call this
805 * after resuming from a partition hibernation or migration in order
806 * to maintain the ability to perform live firmware updates. It's not
807 * catastrophic for this method to be absent or to fail; just log the
808 * condition in that case.
809 *
810 * Context: This function may sleep.
811 */
rtas_activate_firmware(void)812 void rtas_activate_firmware(void)
813 {
814 int token;
815 int fwrc;
816
817 token = rtas_token("ibm,activate-firmware");
818 if (token == RTAS_UNKNOWN_SERVICE) {
819 pr_notice("ibm,activate-firmware method unavailable\n");
820 return;
821 }
822
823 do {
824 fwrc = rtas_call(token, 0, 1, NULL);
825 } while (rtas_busy_delay(fwrc));
826
827 if (fwrc)
828 pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
829 }
830
831 #ifdef CONFIG_PPC_PSERIES
832 /**
833 * rtas_call_reentrant() - Used for reentrant rtas calls
834 * @token: Token for desired reentrant RTAS call
835 * @nargs: Number of Input Parameters
836 * @nret: Number of Output Parameters
837 * @outputs: Array of outputs
838 * @...: Inputs for desired RTAS call
839 *
840 * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off",
841 * "ibm,get-xive" and "ibm,set-xive" are currently reentrant.
842 * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but
843 * PACA one instead.
844 *
845 * Return: -1 on error,
846 * First output value of RTAS call if (nret > 0),
847 * 0 otherwise,
848 */
rtas_call_reentrant(int token,int nargs,int nret,int * outputs,...)849 int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
850 {
851 va_list list;
852 struct rtas_args *args;
853 unsigned long flags;
854 int i, ret = 0;
855
856 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
857 return -1;
858
859 local_irq_save(flags);
860 preempt_disable();
861
862 /* We use the per-cpu (PACA) rtas args buffer */
863 args = local_paca->rtas_args_reentrant;
864
865 va_start(list, outputs);
866 va_rtas_call_unlocked(args, token, nargs, nret, list);
867 va_end(list);
868
869 if (nret > 1 && outputs)
870 for (i = 0; i < nret - 1; ++i)
871 outputs[i] = be32_to_cpu(args->rets[i + 1]);
872
873 if (nret > 0)
874 ret = be32_to_cpu(args->rets[0]);
875
876 local_irq_restore(flags);
877 preempt_enable();
878
879 return ret;
880 }
881
882 #endif /* CONFIG_PPC_PSERIES */
883
884 /**
885 * Find a specific pseries error log in an RTAS extended event log.
886 * @log: RTAS error/event log
887 * @section_id: two character section identifier
888 *
889 * Returns a pointer to the specified errorlog or NULL if not found.
890 */
get_pseries_errorlog(struct rtas_error_log * log,uint16_t section_id)891 struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
892 uint16_t section_id)
893 {
894 struct rtas_ext_event_log_v6 *ext_log =
895 (struct rtas_ext_event_log_v6 *)log->buffer;
896 struct pseries_errorlog *sect;
897 unsigned char *p, *log_end;
898 uint32_t ext_log_length = rtas_error_extended_log_length(log);
899 uint8_t log_format = rtas_ext_event_log_format(ext_log);
900 uint32_t company_id = rtas_ext_event_company_id(ext_log);
901
902 /* Check that we understand the format */
903 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
904 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
905 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
906 return NULL;
907
908 log_end = log->buffer + ext_log_length;
909 p = ext_log->vendor_log;
910
911 while (p < log_end) {
912 sect = (struct pseries_errorlog *)p;
913 if (pseries_errorlog_id(sect) == section_id)
914 return sect;
915 p += pseries_errorlog_length(sect);
916 }
917
918 return NULL;
919 }
920
921 #ifdef CONFIG_PPC_RTAS_FILTER
922
923 /*
924 * The sys_rtas syscall, as originally designed, allows root to pass
925 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
926 * can be abused to write to arbitrary memory and do other things that
927 * are potentially harmful to system integrity, and thus should only
928 * be used inside the kernel and not exposed to userspace.
929 *
930 * All known legitimate users of the sys_rtas syscall will only ever
931 * pass addresses that fall within the RMO buffer, and use a known
932 * subset of RTAS calls.
933 *
934 * Accordingly, we filter RTAS requests to check that the call is
935 * permitted, and that provided pointers fall within the RMO buffer.
936 * The rtas_filters list contains an entry for each permitted call,
937 * with the indexes of the parameters which are expected to contain
938 * addresses and sizes of buffers allocated inside the RMO buffer.
939 */
940 struct rtas_filter {
941 const char *name;
942 int token;
943 /* Indexes into the args buffer, -1 if not used */
944 int buf_idx1;
945 int size_idx1;
946 int buf_idx2;
947 int size_idx2;
948
949 int fixed_size;
950 };
951
952 static struct rtas_filter rtas_filters[] __ro_after_init = {
953 { "ibm,activate-firmware", -1, -1, -1, -1, -1 },
954 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */
955 { "display-character", -1, -1, -1, -1, -1 },
956 { "ibm,display-message", -1, 0, -1, -1, -1 },
957 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
958 { "ibm,close-errinjct", -1, -1, -1, -1, -1 },
959 { "ibm,open-errinjct", -1, -1, -1, -1, -1 },
960 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
961 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
962 { "ibm,get-indices", -1, 2, 3, -1, -1 },
963 { "get-power-level", -1, -1, -1, -1, -1 },
964 { "get-sensor-state", -1, -1, -1, -1, -1 },
965 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
966 { "get-time-of-day", -1, -1, -1, -1, -1 },
967 { "ibm,get-vpd", -1, 0, -1, 1, 2 },
968 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
969 { "ibm,platform-dump", -1, 4, 5, -1, -1 },
970 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
971 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
972 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
973 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
974 { "set-indicator", -1, -1, -1, -1, -1 },
975 { "set-power-level", -1, -1, -1, -1, -1 },
976 { "set-time-for-power-on", -1, -1, -1, -1, -1 },
977 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
978 { "set-time-of-day", -1, -1, -1, -1, -1 },
979 #ifdef CONFIG_CPU_BIG_ENDIAN
980 { "ibm,suspend-me", -1, -1, -1, -1, -1 },
981 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
982 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
983 #endif
984 { "ibm,physical-attestation", -1, 0, 1, -1, -1 },
985 };
986
in_rmo_buf(u32 base,u32 end)987 static bool in_rmo_buf(u32 base, u32 end)
988 {
989 return base >= rtas_rmo_buf &&
990 base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) &&
991 base <= end &&
992 end >= rtas_rmo_buf &&
993 end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE);
994 }
995
block_rtas_call(int token,int nargs,struct rtas_args * args)996 static bool block_rtas_call(int token, int nargs,
997 struct rtas_args *args)
998 {
999 int i;
1000
1001 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1002 struct rtas_filter *f = &rtas_filters[i];
1003 u32 base, size, end;
1004
1005 if (token != f->token)
1006 continue;
1007
1008 if (f->buf_idx1 != -1) {
1009 base = be32_to_cpu(args->args[f->buf_idx1]);
1010 if (f->size_idx1 != -1)
1011 size = be32_to_cpu(args->args[f->size_idx1]);
1012 else if (f->fixed_size)
1013 size = f->fixed_size;
1014 else
1015 size = 1;
1016
1017 end = base + size - 1;
1018 if (!in_rmo_buf(base, end))
1019 goto err;
1020 }
1021
1022 if (f->buf_idx2 != -1) {
1023 base = be32_to_cpu(args->args[f->buf_idx2]);
1024 if (f->size_idx2 != -1)
1025 size = be32_to_cpu(args->args[f->size_idx2]);
1026 else if (f->fixed_size)
1027 size = f->fixed_size;
1028 else
1029 size = 1;
1030 end = base + size - 1;
1031
1032 /*
1033 * Special case for ibm,configure-connector where the
1034 * address can be 0
1035 */
1036 if (!strcmp(f->name, "ibm,configure-connector") &&
1037 base == 0)
1038 return false;
1039
1040 if (!in_rmo_buf(base, end))
1041 goto err;
1042 }
1043
1044 return false;
1045 }
1046
1047 err:
1048 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
1049 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
1050 token, nargs, current->comm);
1051 return true;
1052 }
1053
rtas_syscall_filter_init(void)1054 static void __init rtas_syscall_filter_init(void)
1055 {
1056 unsigned int i;
1057
1058 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++)
1059 rtas_filters[i].token = rtas_token(rtas_filters[i].name);
1060 }
1061
1062 #else
1063
block_rtas_call(int token,int nargs,struct rtas_args * args)1064 static bool block_rtas_call(int token, int nargs,
1065 struct rtas_args *args)
1066 {
1067 return false;
1068 }
1069
rtas_syscall_filter_init(void)1070 static void __init rtas_syscall_filter_init(void)
1071 {
1072 }
1073
1074 #endif /* CONFIG_PPC_RTAS_FILTER */
1075
1076 /* We assume to be passed big endian arguments */
SYSCALL_DEFINE1(rtas,struct rtas_args __user *,uargs)1077 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
1078 {
1079 struct rtas_args args;
1080 unsigned long flags;
1081 char *buff_copy, *errbuf = NULL;
1082 int nargs, nret, token;
1083
1084 if (!capable(CAP_SYS_ADMIN))
1085 return -EPERM;
1086
1087 if (!rtas.entry)
1088 return -EINVAL;
1089
1090 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1091 return -EFAULT;
1092
1093 nargs = be32_to_cpu(args.nargs);
1094 nret = be32_to_cpu(args.nret);
1095 token = be32_to_cpu(args.token);
1096
1097 if (nargs >= ARRAY_SIZE(args.args)
1098 || nret > ARRAY_SIZE(args.args)
1099 || nargs + nret > ARRAY_SIZE(args.args))
1100 return -EINVAL;
1101
1102 /* Copy in args. */
1103 if (copy_from_user(args.args, uargs->args,
1104 nargs * sizeof(rtas_arg_t)) != 0)
1105 return -EFAULT;
1106
1107 if (token == RTAS_UNKNOWN_SERVICE)
1108 return -EINVAL;
1109
1110 args.rets = &args.args[nargs];
1111 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1112
1113 if (block_rtas_call(token, nargs, &args))
1114 return -EINVAL;
1115
1116 /* Need to handle ibm,suspend_me call specially */
1117 if (token == rtas_token("ibm,suspend-me")) {
1118
1119 /*
1120 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1121 * endian, or at least the hcall within it requires it.
1122 */
1123 int rc = 0;
1124 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1125 | be32_to_cpu(args.args[1]);
1126 rc = rtas_syscall_dispatch_ibm_suspend_me(handle);
1127 if (rc == -EAGAIN)
1128 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1129 else if (rc == -EIO)
1130 args.rets[0] = cpu_to_be32(-1);
1131 else if (rc)
1132 return rc;
1133 goto copy_return;
1134 }
1135
1136 buff_copy = get_errorlog_buffer();
1137
1138 flags = lock_rtas();
1139
1140 rtas.args = args;
1141 enter_rtas(__pa(&rtas.args));
1142 args = rtas.args;
1143
1144 /* A -1 return code indicates that the last command couldn't
1145 be completed due to a hardware error. */
1146 if (be32_to_cpu(args.rets[0]) == -1)
1147 errbuf = __fetch_rtas_last_error(buff_copy);
1148
1149 unlock_rtas(flags);
1150
1151 if (buff_copy) {
1152 if (errbuf)
1153 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1154 kfree(buff_copy);
1155 }
1156
1157 copy_return:
1158 /* Copy out args. */
1159 if (copy_to_user(uargs->args + nargs,
1160 args.args + nargs,
1161 nret * sizeof(rtas_arg_t)) != 0)
1162 return -EFAULT;
1163
1164 return 0;
1165 }
1166
1167 /*
1168 * Call early during boot, before mem init, to retrieve the RTAS
1169 * information from the device-tree and allocate the RMO buffer for userland
1170 * accesses.
1171 */
rtas_initialize(void)1172 void __init rtas_initialize(void)
1173 {
1174 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1175 u32 base, size, entry;
1176 int no_base, no_size, no_entry;
1177
1178 /* Get RTAS dev node and fill up our "rtas" structure with infos
1179 * about it.
1180 */
1181 rtas.dev = of_find_node_by_name(NULL, "rtas");
1182 if (!rtas.dev)
1183 return;
1184
1185 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
1186 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
1187 if (no_base || no_size) {
1188 of_node_put(rtas.dev);
1189 rtas.dev = NULL;
1190 return;
1191 }
1192
1193 rtas.base = base;
1194 rtas.size = size;
1195 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
1196 rtas.entry = no_entry ? rtas.base : entry;
1197
1198 /* If RTAS was found, allocate the RMO buffer for it and look for
1199 * the stop-self token if any
1200 */
1201 #ifdef CONFIG_PPC64
1202 if (firmware_has_feature(FW_FEATURE_LPAR))
1203 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1204 #endif
1205 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE,
1206 0, rtas_region);
1207 if (!rtas_rmo_buf)
1208 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
1209 PAGE_SIZE, &rtas_region);
1210
1211 #ifdef CONFIG_RTAS_ERROR_LOGGING
1212 rtas_last_error_token = rtas_token("rtas-last-error");
1213 #endif
1214
1215 rtas_syscall_filter_init();
1216 }
1217
early_init_dt_scan_rtas(unsigned long node,const char * uname,int depth,void * data)1218 int __init early_init_dt_scan_rtas(unsigned long node,
1219 const char *uname, int depth, void *data)
1220 {
1221 const u32 *basep, *entryp, *sizep;
1222
1223 if (depth != 1 || strcmp(uname, "rtas") != 0)
1224 return 0;
1225
1226 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1227 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1228 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1229
1230 if (basep && entryp && sizep) {
1231 rtas.base = *basep;
1232 rtas.entry = *entryp;
1233 rtas.size = *sizep;
1234 }
1235
1236 #ifdef CONFIG_UDBG_RTAS_CONSOLE
1237 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1238 if (basep)
1239 rtas_putchar_token = *basep;
1240
1241 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1242 if (basep)
1243 rtas_getchar_token = *basep;
1244
1245 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1246 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1247 udbg_init_rtas_console();
1248
1249 #endif
1250
1251 /* break now */
1252 return 1;
1253 }
1254
1255 static arch_spinlock_t timebase_lock;
1256 static u64 timebase = 0;
1257
rtas_give_timebase(void)1258 void rtas_give_timebase(void)
1259 {
1260 unsigned long flags;
1261
1262 local_irq_save(flags);
1263 hard_irq_disable();
1264 arch_spin_lock(&timebase_lock);
1265 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1266 timebase = get_tb();
1267 arch_spin_unlock(&timebase_lock);
1268
1269 while (timebase)
1270 barrier();
1271 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1272 local_irq_restore(flags);
1273 }
1274
rtas_take_timebase(void)1275 void rtas_take_timebase(void)
1276 {
1277 while (!timebase)
1278 barrier();
1279 arch_spin_lock(&timebase_lock);
1280 set_tb(timebase >> 32, timebase & 0xffffffff);
1281 timebase = 0;
1282 arch_spin_unlock(&timebase_lock);
1283 }
1284