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
45 /* This is here deliberately so it's only used in this file */
46 void enter_rtas(unsigned long);
47
48 struct rtas_t rtas = {
49 .lock = __ARCH_SPIN_LOCK_UNLOCKED
50 };
51 EXPORT_SYMBOL(rtas);
52
53 DEFINE_SPINLOCK(rtas_data_buf_lock);
54 EXPORT_SYMBOL_GPL(rtas_data_buf_lock);
55
56 char rtas_data_buf[RTAS_DATA_BUF_SIZE] __aligned(SZ_4K);
57 EXPORT_SYMBOL_GPL(rtas_data_buf);
58
59 unsigned long rtas_rmo_buf;
60
61 /*
62 * If non-NULL, this gets called when the kernel terminates.
63 * This is done like this so rtas_flash can be a module.
64 */
65 void (*rtas_flash_term_hook)(int);
66 EXPORT_SYMBOL_GPL(rtas_flash_term_hook);
67
68 /* RTAS use home made raw locking instead of spin_lock_irqsave
69 * because those can be called from within really nasty contexts
70 * such as having the timebase stopped which would lockup with
71 * normal locks and spinlock debugging enabled
72 */
lock_rtas(void)73 static unsigned long lock_rtas(void)
74 {
75 unsigned long flags;
76
77 local_irq_save(flags);
78 preempt_disable();
79 arch_spin_lock(&rtas.lock);
80 return flags;
81 }
82
unlock_rtas(unsigned long flags)83 static void unlock_rtas(unsigned long flags)
84 {
85 arch_spin_unlock(&rtas.lock);
86 local_irq_restore(flags);
87 preempt_enable();
88 }
89
90 /*
91 * call_rtas_display_status and call_rtas_display_status_delay
92 * are designed only for very early low-level debugging, which
93 * is why the token is hard-coded to 10.
94 */
call_rtas_display_status(unsigned char c)95 static void call_rtas_display_status(unsigned char c)
96 {
97 unsigned long s;
98
99 if (!rtas.base)
100 return;
101
102 s = lock_rtas();
103 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c);
104 unlock_rtas(s);
105 }
106
call_rtas_display_status_delay(char c)107 static void call_rtas_display_status_delay(char c)
108 {
109 static int pending_newline = 0; /* did last write end with unprinted newline? */
110 static int width = 16;
111
112 if (c == '\n') {
113 while (width-- > 0)
114 call_rtas_display_status(' ');
115 width = 16;
116 mdelay(500);
117 pending_newline = 1;
118 } else {
119 if (pending_newline) {
120 call_rtas_display_status('\r');
121 call_rtas_display_status('\n');
122 }
123 pending_newline = 0;
124 if (width--) {
125 call_rtas_display_status(c);
126 udelay(10000);
127 }
128 }
129 }
130
udbg_init_rtas_panel(void)131 void __init udbg_init_rtas_panel(void)
132 {
133 udbg_putc = call_rtas_display_status_delay;
134 }
135
136 #ifdef CONFIG_UDBG_RTAS_CONSOLE
137
138 /* If you think you're dying before early_init_dt_scan_rtas() does its
139 * work, you can hard code the token values for your firmware here and
140 * hardcode rtas.base/entry etc.
141 */
142 static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
143 static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
144
udbg_rtascon_putc(char c)145 static void udbg_rtascon_putc(char c)
146 {
147 int tries;
148
149 if (!rtas.base)
150 return;
151
152 /* Add CRs before LFs */
153 if (c == '\n')
154 udbg_rtascon_putc('\r');
155
156 /* if there is more than one character to be displayed, wait a bit */
157 for (tries = 0; tries < 16; tries++) {
158 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
159 break;
160 udelay(1000);
161 }
162 }
163
udbg_rtascon_getc_poll(void)164 static int udbg_rtascon_getc_poll(void)
165 {
166 int c;
167
168 if (!rtas.base)
169 return -1;
170
171 if (rtas_call(rtas_getchar_token, 0, 2, &c))
172 return -1;
173
174 return c;
175 }
176
udbg_rtascon_getc(void)177 static int udbg_rtascon_getc(void)
178 {
179 int c;
180
181 while ((c = udbg_rtascon_getc_poll()) == -1)
182 ;
183
184 return c;
185 }
186
187
udbg_init_rtas_console(void)188 void __init udbg_init_rtas_console(void)
189 {
190 udbg_putc = udbg_rtascon_putc;
191 udbg_getc = udbg_rtascon_getc;
192 udbg_getc_poll = udbg_rtascon_getc_poll;
193 }
194 #endif /* CONFIG_UDBG_RTAS_CONSOLE */
195
rtas_progress(char * s,unsigned short hex)196 void rtas_progress(char *s, unsigned short hex)
197 {
198 struct device_node *root;
199 int width;
200 const __be32 *p;
201 char *os;
202 static int display_character, set_indicator;
203 static int display_width, display_lines, form_feed;
204 static const int *row_width;
205 static DEFINE_SPINLOCK(progress_lock);
206 static int current_line;
207 static int pending_newline = 0; /* did last write end with unprinted newline? */
208
209 if (!rtas.base)
210 return;
211
212 if (display_width == 0) {
213 display_width = 0x10;
214 if ((root = of_find_node_by_path("/rtas"))) {
215 if ((p = of_get_property(root,
216 "ibm,display-line-length", NULL)))
217 display_width = be32_to_cpu(*p);
218 if ((p = of_get_property(root,
219 "ibm,form-feed", NULL)))
220 form_feed = be32_to_cpu(*p);
221 if ((p = of_get_property(root,
222 "ibm,display-number-of-lines", NULL)))
223 display_lines = be32_to_cpu(*p);
224 row_width = of_get_property(root,
225 "ibm,display-truncation-length", NULL);
226 of_node_put(root);
227 }
228 display_character = rtas_token("display-character");
229 set_indicator = rtas_token("set-indicator");
230 }
231
232 if (display_character == RTAS_UNKNOWN_SERVICE) {
233 /* use hex display if available */
234 if (set_indicator != RTAS_UNKNOWN_SERVICE)
235 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
236 return;
237 }
238
239 spin_lock(&progress_lock);
240
241 /*
242 * Last write ended with newline, but we didn't print it since
243 * it would just clear the bottom line of output. Print it now
244 * instead.
245 *
246 * If no newline is pending and form feed is supported, clear the
247 * display with a form feed; otherwise, print a CR to start output
248 * at the beginning of the line.
249 */
250 if (pending_newline) {
251 rtas_call(display_character, 1, 1, NULL, '\r');
252 rtas_call(display_character, 1, 1, NULL, '\n');
253 pending_newline = 0;
254 } else {
255 current_line = 0;
256 if (form_feed)
257 rtas_call(display_character, 1, 1, NULL,
258 (char)form_feed);
259 else
260 rtas_call(display_character, 1, 1, NULL, '\r');
261 }
262
263 if (row_width)
264 width = row_width[current_line];
265 else
266 width = display_width;
267 os = s;
268 while (*os) {
269 if (*os == '\n' || *os == '\r') {
270 /* If newline is the last character, save it
271 * until next call to avoid bumping up the
272 * display output.
273 */
274 if (*os == '\n' && !os[1]) {
275 pending_newline = 1;
276 current_line++;
277 if (current_line > display_lines-1)
278 current_line = display_lines-1;
279 spin_unlock(&progress_lock);
280 return;
281 }
282
283 /* RTAS wants CR-LF, not just LF */
284
285 if (*os == '\n') {
286 rtas_call(display_character, 1, 1, NULL, '\r');
287 rtas_call(display_character, 1, 1, NULL, '\n');
288 } else {
289 /* CR might be used to re-draw a line, so we'll
290 * leave it alone and not add LF.
291 */
292 rtas_call(display_character, 1, 1, NULL, *os);
293 }
294
295 if (row_width)
296 width = row_width[current_line];
297 else
298 width = display_width;
299 } else {
300 width--;
301 rtas_call(display_character, 1, 1, NULL, *os);
302 }
303
304 os++;
305
306 /* if we overwrite the screen length */
307 if (width <= 0)
308 while ((*os != 0) && (*os != '\n') && (*os != '\r'))
309 os++;
310 }
311
312 spin_unlock(&progress_lock);
313 }
314 EXPORT_SYMBOL_GPL(rtas_progress); /* needed by rtas_flash module */
315
rtas_token(const char * service)316 int rtas_token(const char *service)
317 {
318 const __be32 *tokp;
319 if (rtas.dev == NULL)
320 return RTAS_UNKNOWN_SERVICE;
321 tokp = of_get_property(rtas.dev, service, NULL);
322 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
323 }
324 EXPORT_SYMBOL_GPL(rtas_token);
325
rtas_service_present(const char * service)326 int rtas_service_present(const char *service)
327 {
328 return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
329 }
330 EXPORT_SYMBOL(rtas_service_present);
331
332 #ifdef CONFIG_RTAS_ERROR_LOGGING
333 /*
334 * Return the firmware-specified size of the error log buffer
335 * for all rtas calls that require an error buffer argument.
336 * This includes 'check-exception' and 'rtas-last-error'.
337 */
rtas_get_error_log_max(void)338 int rtas_get_error_log_max(void)
339 {
340 static int rtas_error_log_max;
341 if (rtas_error_log_max)
342 return rtas_error_log_max;
343
344 rtas_error_log_max = rtas_token ("rtas-error-log-max");
345 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
346 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
347 printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
348 rtas_error_log_max);
349 rtas_error_log_max = RTAS_ERROR_LOG_MAX;
350 }
351 return rtas_error_log_max;
352 }
353 EXPORT_SYMBOL(rtas_get_error_log_max);
354
355
356 static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
357 static int rtas_last_error_token;
358
359 /** Return a copy of the detailed error text associated with the
360 * most recent failed call to rtas. Because the error text
361 * might go stale if there are any other intervening rtas calls,
362 * this routine must be called atomically with whatever produced
363 * the error (i.e. with rtas.lock still held from the previous call).
364 */
__fetch_rtas_last_error(char * altbuf)365 static char *__fetch_rtas_last_error(char *altbuf)
366 {
367 struct rtas_args err_args, save_args;
368 u32 bufsz;
369 char *buf = NULL;
370
371 if (rtas_last_error_token == -1)
372 return NULL;
373
374 bufsz = rtas_get_error_log_max();
375
376 err_args.token = cpu_to_be32(rtas_last_error_token);
377 err_args.nargs = cpu_to_be32(2);
378 err_args.nret = cpu_to_be32(1);
379 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
380 err_args.args[1] = cpu_to_be32(bufsz);
381 err_args.args[2] = 0;
382
383 save_args = rtas.args;
384 rtas.args = err_args;
385
386 enter_rtas(__pa(&rtas.args));
387
388 err_args = rtas.args;
389 rtas.args = save_args;
390
391 /* Log the error in the unlikely case that there was one. */
392 if (unlikely(err_args.args[2] == 0)) {
393 if (altbuf) {
394 buf = altbuf;
395 } else {
396 buf = rtas_err_buf;
397 if (slab_is_available())
398 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
399 }
400 if (buf)
401 memmove(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
402 }
403
404 return buf;
405 }
406
407 #define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
408
409 #else /* CONFIG_RTAS_ERROR_LOGGING */
410 #define __fetch_rtas_last_error(x) NULL
411 #define get_errorlog_buffer() NULL
412 #endif
413
414
415 static void
va_rtas_call_unlocked(struct rtas_args * args,int token,int nargs,int nret,va_list list)416 va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
417 va_list list)
418 {
419 int i;
420
421 args->token = cpu_to_be32(token);
422 args->nargs = cpu_to_be32(nargs);
423 args->nret = cpu_to_be32(nret);
424 args->rets = &(args->args[nargs]);
425
426 for (i = 0; i < nargs; ++i)
427 args->args[i] = cpu_to_be32(va_arg(list, __u32));
428
429 for (i = 0; i < nret; ++i)
430 args->rets[i] = 0;
431
432 enter_rtas(__pa(args));
433 }
434
rtas_call_unlocked(struct rtas_args * args,int token,int nargs,int nret,...)435 void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
436 {
437 va_list list;
438
439 va_start(list, nret);
440 va_rtas_call_unlocked(args, token, nargs, nret, list);
441 va_end(list);
442 }
443
rtas_call(int token,int nargs,int nret,int * outputs,...)444 int rtas_call(int token, int nargs, int nret, int *outputs, ...)
445 {
446 va_list list;
447 int i;
448 unsigned long s;
449 struct rtas_args *rtas_args;
450 char *buff_copy = NULL;
451 int ret;
452
453 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
454 return -1;
455
456 s = lock_rtas();
457
458 /* We use the global rtas args buffer */
459 rtas_args = &rtas.args;
460
461 va_start(list, outputs);
462 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list);
463 va_end(list);
464
465 /* A -1 return code indicates that the last command couldn't
466 be completed due to a hardware error. */
467 if (be32_to_cpu(rtas_args->rets[0]) == -1)
468 buff_copy = __fetch_rtas_last_error(NULL);
469
470 if (nret > 1 && outputs != NULL)
471 for (i = 0; i < nret-1; ++i)
472 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
473 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
474
475 unlock_rtas(s);
476
477 if (buff_copy) {
478 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
479 if (slab_is_available())
480 kfree(buff_copy);
481 }
482 return ret;
483 }
484 EXPORT_SYMBOL_GPL(rtas_call);
485
486 /* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status
487 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
488 */
rtas_busy_delay_time(int status)489 unsigned int rtas_busy_delay_time(int status)
490 {
491 int order;
492 unsigned int ms = 0;
493
494 if (status == RTAS_BUSY) {
495 ms = 1;
496 } else if (status >= RTAS_EXTENDED_DELAY_MIN &&
497 status <= RTAS_EXTENDED_DELAY_MAX) {
498 order = status - RTAS_EXTENDED_DELAY_MIN;
499 for (ms = 1; order > 0; order--)
500 ms *= 10;
501 }
502
503 return ms;
504 }
505 EXPORT_SYMBOL(rtas_busy_delay_time);
506
507 /* For an RTAS busy status code, perform the hinted delay. */
rtas_busy_delay(int status)508 unsigned int rtas_busy_delay(int status)
509 {
510 unsigned int ms;
511
512 might_sleep();
513 ms = rtas_busy_delay_time(status);
514 if (ms && need_resched())
515 msleep(ms);
516
517 return ms;
518 }
519 EXPORT_SYMBOL_GPL(rtas_busy_delay);
520
rtas_error_rc(int rtas_rc)521 static int rtas_error_rc(int rtas_rc)
522 {
523 int rc;
524
525 switch (rtas_rc) {
526 case -1: /* Hardware Error */
527 rc = -EIO;
528 break;
529 case -3: /* Bad indicator/domain/etc */
530 rc = -EINVAL;
531 break;
532 case -9000: /* Isolation error */
533 rc = -EFAULT;
534 break;
535 case -9001: /* Outstanding TCE/PTE */
536 rc = -EEXIST;
537 break;
538 case -9002: /* No usable slot */
539 rc = -ENODEV;
540 break;
541 default:
542 printk(KERN_ERR "%s: unexpected RTAS error %d\n",
543 __func__, rtas_rc);
544 rc = -ERANGE;
545 break;
546 }
547 return rc;
548 }
549
rtas_get_power_level(int powerdomain,int * level)550 int rtas_get_power_level(int powerdomain, int *level)
551 {
552 int token = rtas_token("get-power-level");
553 int rc;
554
555 if (token == RTAS_UNKNOWN_SERVICE)
556 return -ENOENT;
557
558 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
559 udelay(1);
560
561 if (rc < 0)
562 return rtas_error_rc(rc);
563 return rc;
564 }
565 EXPORT_SYMBOL_GPL(rtas_get_power_level);
566
rtas_set_power_level(int powerdomain,int level,int * setlevel)567 int rtas_set_power_level(int powerdomain, int level, int *setlevel)
568 {
569 int token = rtas_token("set-power-level");
570 int rc;
571
572 if (token == RTAS_UNKNOWN_SERVICE)
573 return -ENOENT;
574
575 do {
576 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
577 } while (rtas_busy_delay(rc));
578
579 if (rc < 0)
580 return rtas_error_rc(rc);
581 return rc;
582 }
583 EXPORT_SYMBOL_GPL(rtas_set_power_level);
584
rtas_get_sensor(int sensor,int index,int * state)585 int rtas_get_sensor(int sensor, int index, int *state)
586 {
587 int token = rtas_token("get-sensor-state");
588 int rc;
589
590 if (token == RTAS_UNKNOWN_SERVICE)
591 return -ENOENT;
592
593 do {
594 rc = rtas_call(token, 2, 2, state, sensor, index);
595 } while (rtas_busy_delay(rc));
596
597 if (rc < 0)
598 return rtas_error_rc(rc);
599 return rc;
600 }
601 EXPORT_SYMBOL_GPL(rtas_get_sensor);
602
rtas_get_sensor_fast(int sensor,int index,int * state)603 int rtas_get_sensor_fast(int sensor, int index, int *state)
604 {
605 int token = rtas_token("get-sensor-state");
606 int rc;
607
608 if (token == RTAS_UNKNOWN_SERVICE)
609 return -ENOENT;
610
611 rc = rtas_call(token, 2, 2, state, sensor, index);
612 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
613 rc <= RTAS_EXTENDED_DELAY_MAX));
614
615 if (rc < 0)
616 return rtas_error_rc(rc);
617 return rc;
618 }
619
rtas_indicator_present(int token,int * maxindex)620 bool rtas_indicator_present(int token, int *maxindex)
621 {
622 int proplen, count, i;
623 const struct indicator_elem {
624 __be32 token;
625 __be32 maxindex;
626 } *indicators;
627
628 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
629 if (!indicators)
630 return false;
631
632 count = proplen / sizeof(struct indicator_elem);
633
634 for (i = 0; i < count; i++) {
635 if (__be32_to_cpu(indicators[i].token) != token)
636 continue;
637 if (maxindex)
638 *maxindex = __be32_to_cpu(indicators[i].maxindex);
639 return true;
640 }
641
642 return false;
643 }
644 EXPORT_SYMBOL(rtas_indicator_present);
645
rtas_set_indicator(int indicator,int index,int new_value)646 int rtas_set_indicator(int indicator, int index, int new_value)
647 {
648 int token = rtas_token("set-indicator");
649 int rc;
650
651 if (token == RTAS_UNKNOWN_SERVICE)
652 return -ENOENT;
653
654 do {
655 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
656 } while (rtas_busy_delay(rc));
657
658 if (rc < 0)
659 return rtas_error_rc(rc);
660 return rc;
661 }
662 EXPORT_SYMBOL_GPL(rtas_set_indicator);
663
664 /*
665 * Ignoring RTAS extended delay
666 */
rtas_set_indicator_fast(int indicator,int index,int new_value)667 int rtas_set_indicator_fast(int indicator, int index, int new_value)
668 {
669 int rc;
670 int token = rtas_token("set-indicator");
671
672 if (token == RTAS_UNKNOWN_SERVICE)
673 return -ENOENT;
674
675 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
676
677 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
678 rc <= RTAS_EXTENDED_DELAY_MAX));
679
680 if (rc < 0)
681 return rtas_error_rc(rc);
682
683 return rc;
684 }
685
rtas_restart(char * cmd)686 void __noreturn rtas_restart(char *cmd)
687 {
688 if (rtas_flash_term_hook)
689 rtas_flash_term_hook(SYS_RESTART);
690 printk("RTAS system-reboot returned %d\n",
691 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
692 for (;;);
693 }
694
rtas_power_off(void)695 void rtas_power_off(void)
696 {
697 if (rtas_flash_term_hook)
698 rtas_flash_term_hook(SYS_POWER_OFF);
699 /* allow power on only with power button press */
700 printk("RTAS power-off returned %d\n",
701 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
702 for (;;);
703 }
704
rtas_halt(void)705 void __noreturn rtas_halt(void)
706 {
707 if (rtas_flash_term_hook)
708 rtas_flash_term_hook(SYS_HALT);
709 /* allow power on only with power button press */
710 printk("RTAS power-off returned %d\n",
711 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
712 for (;;);
713 }
714
715 /* Must be in the RMO region, so we place it here */
716 static char rtas_os_term_buf[2048];
717 static s32 ibm_os_term_token = RTAS_UNKNOWN_SERVICE;
718
rtas_os_term(char * str)719 void rtas_os_term(char *str)
720 {
721 int status;
722
723 /*
724 * Firmware with the ibm,extended-os-term property is guaranteed
725 * to always return from an ibm,os-term call. Earlier versions without
726 * this property may terminate the partition which we want to avoid
727 * since it interferes with panic_timeout.
728 */
729 if (ibm_os_term_token == RTAS_UNKNOWN_SERVICE)
730 return;
731
732 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
733
734 /*
735 * Keep calling as long as RTAS returns a "try again" status,
736 * but don't use rtas_busy_delay(), which potentially
737 * schedules.
738 */
739 do {
740 status = rtas_call(ibm_os_term_token, 1, 1, NULL,
741 __pa(rtas_os_term_buf));
742 } while (rtas_busy_delay_time(status));
743
744 if (status != 0)
745 printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
746 }
747
748 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
749 #ifdef CONFIG_PPC_PSERIES
__rtas_suspend_last_cpu(struct rtas_suspend_me_data * data,int wake_when_done)750 static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
751 {
752 u16 slb_size = mmu_slb_size;
753 int rc = H_MULTI_THREADS_ACTIVE;
754 int cpu;
755
756 slb_set_size(SLB_MIN_SIZE);
757 printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id());
758
759 while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) &&
760 !atomic_read(&data->error))
761 rc = rtas_call(data->token, 0, 1, NULL);
762
763 if (rc || atomic_read(&data->error)) {
764 printk(KERN_DEBUG "ibm,suspend-me returned %d\n", rc);
765 slb_set_size(slb_size);
766 }
767
768 if (atomic_read(&data->error))
769 rc = atomic_read(&data->error);
770
771 atomic_set(&data->error, rc);
772 pSeries_coalesce_init();
773
774 if (wake_when_done) {
775 atomic_set(&data->done, 1);
776
777 for_each_online_cpu(cpu)
778 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
779 }
780
781 if (atomic_dec_return(&data->working) == 0)
782 complete(data->complete);
783
784 return rc;
785 }
786
rtas_suspend_last_cpu(struct rtas_suspend_me_data * data)787 int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data)
788 {
789 atomic_inc(&data->working);
790 return __rtas_suspend_last_cpu(data, 0);
791 }
792
__rtas_suspend_cpu(struct rtas_suspend_me_data * data,int wake_when_done)793 static int __rtas_suspend_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
794 {
795 long rc = H_SUCCESS;
796 unsigned long msr_save;
797 int cpu;
798
799 atomic_inc(&data->working);
800
801 /* really need to ensure MSR.EE is off for H_JOIN */
802 msr_save = mfmsr();
803 mtmsr(msr_save & ~(MSR_EE));
804
805 while (rc == H_SUCCESS && !atomic_read(&data->done) && !atomic_read(&data->error))
806 rc = plpar_hcall_norets(H_JOIN);
807
808 mtmsr(msr_save);
809
810 if (rc == H_SUCCESS) {
811 /* This cpu was prodded and the suspend is complete. */
812 goto out;
813 } else if (rc == H_CONTINUE) {
814 /* All other cpus are in H_JOIN, this cpu does
815 * the suspend.
816 */
817 return __rtas_suspend_last_cpu(data, wake_when_done);
818 } else {
819 printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
820 smp_processor_id(), rc);
821 atomic_set(&data->error, rc);
822 }
823
824 if (wake_when_done) {
825 atomic_set(&data->done, 1);
826
827 /* This cpu did the suspend or got an error; in either case,
828 * we need to prod all other other cpus out of join state.
829 * Extra prods are harmless.
830 */
831 for_each_online_cpu(cpu)
832 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
833 }
834 out:
835 if (atomic_dec_return(&data->working) == 0)
836 complete(data->complete);
837 return rc;
838 }
839
rtas_suspend_cpu(struct rtas_suspend_me_data * data)840 int rtas_suspend_cpu(struct rtas_suspend_me_data *data)
841 {
842 return __rtas_suspend_cpu(data, 0);
843 }
844
rtas_percpu_suspend_me(void * info)845 static void rtas_percpu_suspend_me(void *info)
846 {
847 __rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
848 }
849
rtas_ibm_suspend_me(u64 handle)850 int rtas_ibm_suspend_me(u64 handle)
851 {
852 long state;
853 long rc;
854 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
855 struct rtas_suspend_me_data data;
856 DECLARE_COMPLETION_ONSTACK(done);
857
858 if (!rtas_service_present("ibm,suspend-me"))
859 return -ENOSYS;
860
861 /* Make sure the state is valid */
862 rc = plpar_hcall(H_VASI_STATE, retbuf, handle);
863
864 state = retbuf[0];
865
866 if (rc) {
867 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
868 return rc;
869 } else if (state == H_VASI_ENABLED) {
870 return -EAGAIN;
871 } else if (state != H_VASI_SUSPENDING) {
872 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
873 state);
874 return -EIO;
875 }
876
877 atomic_set(&data.working, 0);
878 atomic_set(&data.done, 0);
879 atomic_set(&data.error, 0);
880 data.token = rtas_token("ibm,suspend-me");
881 data.complete = &done;
882
883 lock_device_hotplug();
884
885 cpu_hotplug_disable();
886
887 /* Call function on all CPUs. One of us will make the
888 * rtas call
889 */
890 on_each_cpu(rtas_percpu_suspend_me, &data, 0);
891
892 wait_for_completion(&done);
893
894 if (atomic_read(&data.error) != 0)
895 printk(KERN_ERR "Error doing global join\n");
896
897
898 cpu_hotplug_enable();
899
900 unlock_device_hotplug();
901
902 return atomic_read(&data.error);
903 }
904 #else /* CONFIG_PPC_PSERIES */
rtas_ibm_suspend_me(u64 handle)905 int rtas_ibm_suspend_me(u64 handle)
906 {
907 return -ENOSYS;
908 }
909 #endif
910
911 /**
912 * Find a specific pseries error log in an RTAS extended event log.
913 * @log: RTAS error/event log
914 * @section_id: two character section identifier
915 *
916 * Returns a pointer to the specified errorlog or NULL if not found.
917 */
get_pseries_errorlog(struct rtas_error_log * log,uint16_t section_id)918 struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
919 uint16_t section_id)
920 {
921 struct rtas_ext_event_log_v6 *ext_log =
922 (struct rtas_ext_event_log_v6 *)log->buffer;
923 struct pseries_errorlog *sect;
924 unsigned char *p, *log_end;
925 uint32_t ext_log_length = rtas_error_extended_log_length(log);
926 uint8_t log_format = rtas_ext_event_log_format(ext_log);
927 uint32_t company_id = rtas_ext_event_company_id(ext_log);
928
929 /* Check that we understand the format */
930 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
931 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
932 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
933 return NULL;
934
935 log_end = log->buffer + ext_log_length;
936 p = ext_log->vendor_log;
937
938 while (p < log_end) {
939 sect = (struct pseries_errorlog *)p;
940 if (pseries_errorlog_id(sect) == section_id)
941 return sect;
942 p += pseries_errorlog_length(sect);
943 }
944
945 return NULL;
946 }
947
948 #ifdef CONFIG_PPC_RTAS_FILTER
949
950 /*
951 * The sys_rtas syscall, as originally designed, allows root to pass
952 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
953 * can be abused to write to arbitrary memory and do other things that
954 * are potentially harmful to system integrity, and thus should only
955 * be used inside the kernel and not exposed to userspace.
956 *
957 * All known legitimate users of the sys_rtas syscall will only ever
958 * pass addresses that fall within the RMO buffer, and use a known
959 * subset of RTAS calls.
960 *
961 * Accordingly, we filter RTAS requests to check that the call is
962 * permitted, and that provided pointers fall within the RMO buffer.
963 * The rtas_filters list contains an entry for each permitted call,
964 * with the indexes of the parameters which are expected to contain
965 * addresses and sizes of buffers allocated inside the RMO buffer.
966 */
967 struct rtas_filter {
968 const char *name;
969 int token;
970 /* Indexes into the args buffer, -1 if not used */
971 int buf_idx1;
972 int size_idx1;
973 int buf_idx2;
974 int size_idx2;
975
976 int fixed_size;
977 };
978
979 static struct rtas_filter rtas_filters[] __ro_after_init = {
980 { "ibm,activate-firmware", -1, -1, -1, -1, -1 },
981 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */
982 { "display-character", -1, -1, -1, -1, -1 },
983 { "ibm,display-message", -1, 0, -1, -1, -1 },
984 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
985 { "ibm,close-errinjct", -1, -1, -1, -1, -1 },
986 { "ibm,open-errinjct", -1, -1, -1, -1, -1 },
987 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
988 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
989 { "ibm,get-indices", -1, 2, 3, -1, -1 },
990 { "get-power-level", -1, -1, -1, -1, -1 },
991 { "get-sensor-state", -1, -1, -1, -1, -1 },
992 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
993 { "get-time-of-day", -1, -1, -1, -1, -1 },
994 { "ibm,get-vpd", -1, 0, -1, 1, 2 },
995 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
996 { "ibm,platform-dump", -1, 4, 5, -1, -1 }, /* Special cased */
997 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
998 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
999 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
1000 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
1001 { "set-indicator", -1, -1, -1, -1, -1 },
1002 { "set-power-level", -1, -1, -1, -1, -1 },
1003 { "set-time-for-power-on", -1, -1, -1, -1, -1 },
1004 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
1005 { "set-time-of-day", -1, -1, -1, -1, -1 },
1006 { "ibm,suspend-me", -1, -1, -1, -1, -1 },
1007 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
1008 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
1009 { "ibm,physical-attestation", -1, 0, 1, -1, -1 },
1010 };
1011
in_rmo_buf(u32 base,u32 end)1012 static bool in_rmo_buf(u32 base, u32 end)
1013 {
1014 return base >= rtas_rmo_buf &&
1015 base < (rtas_rmo_buf + RTAS_RMOBUF_MAX) &&
1016 base <= end &&
1017 end >= rtas_rmo_buf &&
1018 end < (rtas_rmo_buf + RTAS_RMOBUF_MAX);
1019 }
1020
block_rtas_call(int token,int nargs,struct rtas_args * args)1021 static bool block_rtas_call(int token, int nargs,
1022 struct rtas_args *args)
1023 {
1024 int i;
1025
1026 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1027 struct rtas_filter *f = &rtas_filters[i];
1028 u32 base, size, end;
1029
1030 if (token != f->token)
1031 continue;
1032
1033 if (f->buf_idx1 != -1) {
1034 base = be32_to_cpu(args->args[f->buf_idx1]);
1035 if (f->size_idx1 != -1)
1036 size = be32_to_cpu(args->args[f->size_idx1]);
1037 else if (f->fixed_size)
1038 size = f->fixed_size;
1039 else
1040 size = 1;
1041
1042 end = base + size - 1;
1043
1044 /*
1045 * Special case for ibm,platform-dump - NULL buffer
1046 * address is used to indicate end of dump processing
1047 */
1048 if (!strcmp(f->name, "ibm,platform-dump") &&
1049 base == 0)
1050 return false;
1051
1052 if (!in_rmo_buf(base, end))
1053 goto err;
1054 }
1055
1056 if (f->buf_idx2 != -1) {
1057 base = be32_to_cpu(args->args[f->buf_idx2]);
1058 if (f->size_idx2 != -1)
1059 size = be32_to_cpu(args->args[f->size_idx2]);
1060 else if (f->fixed_size)
1061 size = f->fixed_size;
1062 else
1063 size = 1;
1064 end = base + size - 1;
1065
1066 /*
1067 * Special case for ibm,configure-connector where the
1068 * address can be 0
1069 */
1070 if (!strcmp(f->name, "ibm,configure-connector") &&
1071 base == 0)
1072 return false;
1073
1074 if (!in_rmo_buf(base, end))
1075 goto err;
1076 }
1077
1078 return false;
1079 }
1080
1081 err:
1082 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
1083 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
1084 token, nargs, current->comm);
1085 return true;
1086 }
1087
1088 #else
1089
block_rtas_call(int token,int nargs,struct rtas_args * args)1090 static bool block_rtas_call(int token, int nargs,
1091 struct rtas_args *args)
1092 {
1093 return false;
1094 }
1095
1096 #endif /* CONFIG_PPC_RTAS_FILTER */
1097
1098 /* We assume to be passed big endian arguments */
SYSCALL_DEFINE1(rtas,struct rtas_args __user *,uargs)1099 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
1100 {
1101 struct rtas_args args;
1102 unsigned long flags;
1103 char *buff_copy, *errbuf = NULL;
1104 int nargs, nret, token;
1105
1106 if (!capable(CAP_SYS_ADMIN))
1107 return -EPERM;
1108
1109 if (!rtas.entry)
1110 return -EINVAL;
1111
1112 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1113 return -EFAULT;
1114
1115 nargs = be32_to_cpu(args.nargs);
1116 nret = be32_to_cpu(args.nret);
1117 token = be32_to_cpu(args.token);
1118
1119 if (nargs >= ARRAY_SIZE(args.args)
1120 || nret > ARRAY_SIZE(args.args)
1121 || nargs + nret > ARRAY_SIZE(args.args))
1122 return -EINVAL;
1123
1124 /* Copy in args. */
1125 if (copy_from_user(args.args, uargs->args,
1126 nargs * sizeof(rtas_arg_t)) != 0)
1127 return -EFAULT;
1128
1129 if (token == RTAS_UNKNOWN_SERVICE)
1130 return -EINVAL;
1131
1132 args.rets = &args.args[nargs];
1133 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1134
1135 if (block_rtas_call(token, nargs, &args))
1136 return -EINVAL;
1137
1138 /* Need to handle ibm,suspend_me call specially */
1139 if (token == ibm_suspend_me_token) {
1140
1141 /*
1142 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1143 * endian, or at least the hcall within it requires it.
1144 */
1145 int rc = 0;
1146 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1147 | be32_to_cpu(args.args[1]);
1148 rc = rtas_ibm_suspend_me(handle);
1149 if (rc == -EAGAIN)
1150 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1151 else if (rc == -EIO)
1152 args.rets[0] = cpu_to_be32(-1);
1153 else if (rc)
1154 return rc;
1155 goto copy_return;
1156 }
1157
1158 buff_copy = get_errorlog_buffer();
1159
1160 flags = lock_rtas();
1161
1162 rtas.args = args;
1163 enter_rtas(__pa(&rtas.args));
1164 args = rtas.args;
1165
1166 /* A -1 return code indicates that the last command couldn't
1167 be completed due to a hardware error. */
1168 if (be32_to_cpu(args.rets[0]) == -1)
1169 errbuf = __fetch_rtas_last_error(buff_copy);
1170
1171 unlock_rtas(flags);
1172
1173 if (buff_copy) {
1174 if (errbuf)
1175 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1176 kfree(buff_copy);
1177 }
1178
1179 copy_return:
1180 /* Copy out args. */
1181 if (copy_to_user(uargs->args + nargs,
1182 args.args + nargs,
1183 nret * sizeof(rtas_arg_t)) != 0)
1184 return -EFAULT;
1185
1186 return 0;
1187 }
1188
1189 /*
1190 * Call early during boot, before mem init, to retrieve the RTAS
1191 * information from the device-tree and allocate the RMO buffer for userland
1192 * accesses.
1193 */
rtas_initialize(void)1194 void __init rtas_initialize(void)
1195 {
1196 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1197 u32 base, size, entry;
1198 int no_base, no_size, no_entry;
1199 #ifdef CONFIG_PPC_RTAS_FILTER
1200 int i;
1201 #endif
1202
1203 /* Get RTAS dev node and fill up our "rtas" structure with infos
1204 * about it.
1205 */
1206 rtas.dev = of_find_node_by_name(NULL, "rtas");
1207 if (!rtas.dev)
1208 return;
1209
1210 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
1211 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
1212 if (no_base || no_size) {
1213 of_node_put(rtas.dev);
1214 rtas.dev = NULL;
1215 return;
1216 }
1217
1218 rtas.base = base;
1219 rtas.size = size;
1220 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
1221 rtas.entry = no_entry ? rtas.base : entry;
1222
1223 /*
1224 * Discover these now to avoid device tree lookups in the
1225 * panic path.
1226 */
1227 if (of_property_read_bool(rtas.dev, "ibm,extended-os-term"))
1228 ibm_os_term_token = rtas_token("ibm,os-term");
1229
1230 /* If RTAS was found, allocate the RMO buffer for it and look for
1231 * the stop-self token if any
1232 */
1233 #ifdef CONFIG_PPC64
1234 if (firmware_has_feature(FW_FEATURE_LPAR)) {
1235 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1236 ibm_suspend_me_token = rtas_token("ibm,suspend-me");
1237 }
1238 #endif
1239 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_RMOBUF_MAX, PAGE_SIZE,
1240 0, rtas_region);
1241 if (!rtas_rmo_buf)
1242 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
1243 PAGE_SIZE, &rtas_region);
1244
1245 #ifdef CONFIG_RTAS_ERROR_LOGGING
1246 rtas_last_error_token = rtas_token("rtas-last-error");
1247 #endif
1248
1249 #ifdef CONFIG_PPC_RTAS_FILTER
1250 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1251 rtas_filters[i].token = rtas_token(rtas_filters[i].name);
1252 }
1253 #endif
1254 }
1255
early_init_dt_scan_rtas(unsigned long node,const char * uname,int depth,void * data)1256 int __init early_init_dt_scan_rtas(unsigned long node,
1257 const char *uname, int depth, void *data)
1258 {
1259 const u32 *basep, *entryp, *sizep;
1260
1261 if (depth != 1 || strcmp(uname, "rtas") != 0)
1262 return 0;
1263
1264 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1265 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1266 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1267
1268 #ifdef CONFIG_PPC64
1269 /* need this feature to decide the crashkernel offset */
1270 if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL))
1271 powerpc_firmware_features |= FW_FEATURE_LPAR;
1272 #endif
1273
1274 if (basep && entryp && sizep) {
1275 rtas.base = *basep;
1276 rtas.entry = *entryp;
1277 rtas.size = *sizep;
1278 }
1279
1280 #ifdef CONFIG_UDBG_RTAS_CONSOLE
1281 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1282 if (basep)
1283 rtas_putchar_token = *basep;
1284
1285 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1286 if (basep)
1287 rtas_getchar_token = *basep;
1288
1289 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1290 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1291 udbg_init_rtas_console();
1292
1293 #endif
1294
1295 /* break now */
1296 return 1;
1297 }
1298
1299 static arch_spinlock_t timebase_lock;
1300 static u64 timebase = 0;
1301
rtas_give_timebase(void)1302 void rtas_give_timebase(void)
1303 {
1304 unsigned long flags;
1305
1306 local_irq_save(flags);
1307 hard_irq_disable();
1308 arch_spin_lock(&timebase_lock);
1309 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1310 timebase = get_tb();
1311 arch_spin_unlock(&timebase_lock);
1312
1313 while (timebase)
1314 barrier();
1315 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1316 local_irq_restore(flags);
1317 }
1318
rtas_take_timebase(void)1319 void rtas_take_timebase(void)
1320 {
1321 while (!timebase)
1322 barrier();
1323 arch_spin_lock(&timebase_lock);
1324 set_tb(timebase >> 32, timebase & 0xffffffff);
1325 timebase = 0;
1326 arch_spin_unlock(&timebase_lock);
1327 }
1328