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
rtas_restart(char * cmd)687 void __noreturn rtas_restart(char *cmd)
688 {
689 if (rtas_flash_term_hook)
690 rtas_flash_term_hook(SYS_RESTART);
691 printk("RTAS system-reboot returned %d\n",
692 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
693 for (;;);
694 }
695
rtas_power_off(void)696 void rtas_power_off(void)
697 {
698 if (rtas_flash_term_hook)
699 rtas_flash_term_hook(SYS_POWER_OFF);
700 /* allow power on only with power button press */
701 printk("RTAS power-off returned %d\n",
702 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
703 for (;;);
704 }
705
rtas_halt(void)706 void __noreturn rtas_halt(void)
707 {
708 if (rtas_flash_term_hook)
709 rtas_flash_term_hook(SYS_HALT);
710 /* allow power on only with power button press */
711 printk("RTAS power-off returned %d\n",
712 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
713 for (;;);
714 }
715
716 /* Must be in the RMO region, so we place it here */
717 static char rtas_os_term_buf[2048];
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 (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
730 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
731 return;
732
733 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
734
735 do {
736 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
737 __pa(rtas_os_term_buf));
738 } while (rtas_busy_delay(status));
739
740 if (status != 0)
741 printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
742 }
743
744 static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
745 #ifdef CONFIG_PPC_PSERIES
__rtas_suspend_last_cpu(struct rtas_suspend_me_data * data,int wake_when_done)746 static int __rtas_suspend_last_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
747 {
748 u16 slb_size = mmu_slb_size;
749 int rc = H_MULTI_THREADS_ACTIVE;
750 int cpu;
751
752 slb_set_size(SLB_MIN_SIZE);
753 printk(KERN_DEBUG "calling ibm,suspend-me on cpu %i\n", smp_processor_id());
754
755 while (rc == H_MULTI_THREADS_ACTIVE && !atomic_read(&data->done) &&
756 !atomic_read(&data->error))
757 rc = rtas_call(data->token, 0, 1, NULL);
758
759 if (rc || atomic_read(&data->error)) {
760 printk(KERN_DEBUG "ibm,suspend-me returned %d\n", rc);
761 slb_set_size(slb_size);
762 }
763
764 if (atomic_read(&data->error))
765 rc = atomic_read(&data->error);
766
767 atomic_set(&data->error, rc);
768 pSeries_coalesce_init();
769
770 if (wake_when_done) {
771 atomic_set(&data->done, 1);
772
773 for_each_online_cpu(cpu)
774 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
775 }
776
777 if (atomic_dec_return(&data->working) == 0)
778 complete(data->complete);
779
780 return rc;
781 }
782
rtas_suspend_last_cpu(struct rtas_suspend_me_data * data)783 int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data)
784 {
785 atomic_inc(&data->working);
786 return __rtas_suspend_last_cpu(data, 0);
787 }
788
__rtas_suspend_cpu(struct rtas_suspend_me_data * data,int wake_when_done)789 static int __rtas_suspend_cpu(struct rtas_suspend_me_data *data, int wake_when_done)
790 {
791 long rc = H_SUCCESS;
792 unsigned long msr_save;
793 int cpu;
794
795 atomic_inc(&data->working);
796
797 /* really need to ensure MSR.EE is off for H_JOIN */
798 msr_save = mfmsr();
799 mtmsr(msr_save & ~(MSR_EE));
800
801 while (rc == H_SUCCESS && !atomic_read(&data->done) && !atomic_read(&data->error))
802 rc = plpar_hcall_norets(H_JOIN);
803
804 mtmsr(msr_save);
805
806 if (rc == H_SUCCESS) {
807 /* This cpu was prodded and the suspend is complete. */
808 goto out;
809 } else if (rc == H_CONTINUE) {
810 /* All other cpus are in H_JOIN, this cpu does
811 * the suspend.
812 */
813 return __rtas_suspend_last_cpu(data, wake_when_done);
814 } else {
815 printk(KERN_ERR "H_JOIN on cpu %i failed with rc = %ld\n",
816 smp_processor_id(), rc);
817 atomic_set(&data->error, rc);
818 }
819
820 if (wake_when_done) {
821 atomic_set(&data->done, 1);
822
823 /* This cpu did the suspend or got an error; in either case,
824 * we need to prod all other other cpus out of join state.
825 * Extra prods are harmless.
826 */
827 for_each_online_cpu(cpu)
828 plpar_hcall_norets(H_PROD, get_hard_smp_processor_id(cpu));
829 }
830 out:
831 if (atomic_dec_return(&data->working) == 0)
832 complete(data->complete);
833 return rc;
834 }
835
rtas_suspend_cpu(struct rtas_suspend_me_data * data)836 int rtas_suspend_cpu(struct rtas_suspend_me_data *data)
837 {
838 return __rtas_suspend_cpu(data, 0);
839 }
840
rtas_percpu_suspend_me(void * info)841 static void rtas_percpu_suspend_me(void *info)
842 {
843 __rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
844 }
845
rtas_ibm_suspend_me(u64 handle)846 int rtas_ibm_suspend_me(u64 handle)
847 {
848 long state;
849 long rc;
850 unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
851 struct rtas_suspend_me_data data;
852 DECLARE_COMPLETION_ONSTACK(done);
853
854 if (!rtas_service_present("ibm,suspend-me"))
855 return -ENOSYS;
856
857 /* Make sure the state is valid */
858 rc = plpar_hcall(H_VASI_STATE, retbuf, handle);
859
860 state = retbuf[0];
861
862 if (rc) {
863 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
864 return rc;
865 } else if (state == H_VASI_ENABLED) {
866 return -EAGAIN;
867 } else if (state != H_VASI_SUSPENDING) {
868 printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
869 state);
870 return -EIO;
871 }
872
873 atomic_set(&data.working, 0);
874 atomic_set(&data.done, 0);
875 atomic_set(&data.error, 0);
876 data.token = rtas_token("ibm,suspend-me");
877 data.complete = &done;
878
879 lock_device_hotplug();
880
881 cpu_hotplug_disable();
882
883 /* Call function on all CPUs. One of us will make the
884 * rtas call
885 */
886 on_each_cpu(rtas_percpu_suspend_me, &data, 0);
887
888 wait_for_completion(&done);
889
890 if (atomic_read(&data.error) != 0)
891 printk(KERN_ERR "Error doing global join\n");
892
893
894 cpu_hotplug_enable();
895
896 unlock_device_hotplug();
897
898 return atomic_read(&data.error);
899 }
900
901 /**
902 * rtas_call_reentrant() - Used for reentrant rtas calls
903 * @token: Token for desired reentrant RTAS call
904 * @nargs: Number of Input Parameters
905 * @nret: Number of Output Parameters
906 * @outputs: Array of outputs
907 * @...: Inputs for desired RTAS call
908 *
909 * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off",
910 * "ibm,get-xive" and "ibm,set-xive" are currently reentrant.
911 * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but
912 * PACA one instead.
913 *
914 * Return: -1 on error,
915 * First output value of RTAS call if (nret > 0),
916 * 0 otherwise,
917 */
rtas_call_reentrant(int token,int nargs,int nret,int * outputs,...)918 int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
919 {
920 va_list list;
921 struct rtas_args *args;
922 unsigned long flags;
923 int i, ret = 0;
924
925 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
926 return -1;
927
928 local_irq_save(flags);
929 preempt_disable();
930
931 /* We use the per-cpu (PACA) rtas args buffer */
932 args = local_paca->rtas_args_reentrant;
933
934 va_start(list, outputs);
935 va_rtas_call_unlocked(args, token, nargs, nret, list);
936 va_end(list);
937
938 if (nret > 1 && outputs)
939 for (i = 0; i < nret - 1; ++i)
940 outputs[i] = be32_to_cpu(args->rets[i + 1]);
941
942 if (nret > 0)
943 ret = be32_to_cpu(args->rets[0]);
944
945 local_irq_restore(flags);
946 preempt_enable();
947
948 return ret;
949 }
950
951 #else /* CONFIG_PPC_PSERIES */
rtas_ibm_suspend_me(u64 handle)952 int rtas_ibm_suspend_me(u64 handle)
953 {
954 return -ENOSYS;
955 }
956 #endif
957
958 /**
959 * Find a specific pseries error log in an RTAS extended event log.
960 * @log: RTAS error/event log
961 * @section_id: two character section identifier
962 *
963 * Returns a pointer to the specified errorlog or NULL if not found.
964 */
get_pseries_errorlog(struct rtas_error_log * log,uint16_t section_id)965 struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
966 uint16_t section_id)
967 {
968 struct rtas_ext_event_log_v6 *ext_log =
969 (struct rtas_ext_event_log_v6 *)log->buffer;
970 struct pseries_errorlog *sect;
971 unsigned char *p, *log_end;
972 uint32_t ext_log_length = rtas_error_extended_log_length(log);
973 uint8_t log_format = rtas_ext_event_log_format(ext_log);
974 uint32_t company_id = rtas_ext_event_company_id(ext_log);
975
976 /* Check that we understand the format */
977 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
978 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
979 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
980 return NULL;
981
982 log_end = log->buffer + ext_log_length;
983 p = ext_log->vendor_log;
984
985 while (p < log_end) {
986 sect = (struct pseries_errorlog *)p;
987 if (pseries_errorlog_id(sect) == section_id)
988 return sect;
989 p += pseries_errorlog_length(sect);
990 }
991
992 return NULL;
993 }
994
995 #ifdef CONFIG_PPC_RTAS_FILTER
996
997 /*
998 * The sys_rtas syscall, as originally designed, allows root to pass
999 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
1000 * can be abused to write to arbitrary memory and do other things that
1001 * are potentially harmful to system integrity, and thus should only
1002 * be used inside the kernel and not exposed to userspace.
1003 *
1004 * All known legitimate users of the sys_rtas syscall will only ever
1005 * pass addresses that fall within the RMO buffer, and use a known
1006 * subset of RTAS calls.
1007 *
1008 * Accordingly, we filter RTAS requests to check that the call is
1009 * permitted, and that provided pointers fall within the RMO buffer.
1010 * The rtas_filters list contains an entry for each permitted call,
1011 * with the indexes of the parameters which are expected to contain
1012 * addresses and sizes of buffers allocated inside the RMO buffer.
1013 */
1014 struct rtas_filter {
1015 const char *name;
1016 int token;
1017 /* Indexes into the args buffer, -1 if not used */
1018 int buf_idx1;
1019 int size_idx1;
1020 int buf_idx2;
1021 int size_idx2;
1022
1023 int fixed_size;
1024 };
1025
1026 static struct rtas_filter rtas_filters[] __ro_after_init = {
1027 { "ibm,activate-firmware", -1, -1, -1, -1, -1 },
1028 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */
1029 { "display-character", -1, -1, -1, -1, -1 },
1030 { "ibm,display-message", -1, 0, -1, -1, -1 },
1031 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
1032 { "ibm,close-errinjct", -1, -1, -1, -1, -1 },
1033 { "ibm,open-errinjct", -1, -1, -1, -1, -1 },
1034 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
1035 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
1036 { "ibm,get-indices", -1, 2, 3, -1, -1 },
1037 { "get-power-level", -1, -1, -1, -1, -1 },
1038 { "get-sensor-state", -1, -1, -1, -1, -1 },
1039 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
1040 { "get-time-of-day", -1, -1, -1, -1, -1 },
1041 { "ibm,get-vpd", -1, 0, -1, 1, 2 },
1042 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
1043 { "ibm,platform-dump", -1, 4, 5, -1, -1 },
1044 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
1045 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
1046 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
1047 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
1048 { "set-indicator", -1, -1, -1, -1, -1 },
1049 { "set-power-level", -1, -1, -1, -1, -1 },
1050 { "set-time-for-power-on", -1, -1, -1, -1, -1 },
1051 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
1052 { "set-time-of-day", -1, -1, -1, -1, -1 },
1053 { "ibm,suspend-me", -1, -1, -1, -1, -1 },
1054 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
1055 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
1056 { "ibm,physical-attestation", -1, 0, 1, -1, -1 },
1057 };
1058
in_rmo_buf(u32 base,u32 end)1059 static bool in_rmo_buf(u32 base, u32 end)
1060 {
1061 return base >= rtas_rmo_buf &&
1062 base < (rtas_rmo_buf + RTAS_RMOBUF_MAX) &&
1063 base <= end &&
1064 end >= rtas_rmo_buf &&
1065 end < (rtas_rmo_buf + RTAS_RMOBUF_MAX);
1066 }
1067
block_rtas_call(int token,int nargs,struct rtas_args * args)1068 static bool block_rtas_call(int token, int nargs,
1069 struct rtas_args *args)
1070 {
1071 int i;
1072
1073 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1074 struct rtas_filter *f = &rtas_filters[i];
1075 u32 base, size, end;
1076
1077 if (token != f->token)
1078 continue;
1079
1080 if (f->buf_idx1 != -1) {
1081 base = be32_to_cpu(args->args[f->buf_idx1]);
1082 if (f->size_idx1 != -1)
1083 size = be32_to_cpu(args->args[f->size_idx1]);
1084 else if (f->fixed_size)
1085 size = f->fixed_size;
1086 else
1087 size = 1;
1088
1089 end = base + size - 1;
1090 if (!in_rmo_buf(base, end))
1091 goto err;
1092 }
1093
1094 if (f->buf_idx2 != -1) {
1095 base = be32_to_cpu(args->args[f->buf_idx2]);
1096 if (f->size_idx2 != -1)
1097 size = be32_to_cpu(args->args[f->size_idx2]);
1098 else if (f->fixed_size)
1099 size = f->fixed_size;
1100 else
1101 size = 1;
1102 end = base + size - 1;
1103
1104 /*
1105 * Special case for ibm,configure-connector where the
1106 * address can be 0
1107 */
1108 if (!strcmp(f->name, "ibm,configure-connector") &&
1109 base == 0)
1110 return false;
1111
1112 if (!in_rmo_buf(base, end))
1113 goto err;
1114 }
1115
1116 return false;
1117 }
1118
1119 err:
1120 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
1121 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
1122 token, nargs, current->comm);
1123 return true;
1124 }
1125
1126 #else
1127
block_rtas_call(int token,int nargs,struct rtas_args * args)1128 static bool block_rtas_call(int token, int nargs,
1129 struct rtas_args *args)
1130 {
1131 return false;
1132 }
1133
1134 #endif /* CONFIG_PPC_RTAS_FILTER */
1135
1136 /* We assume to be passed big endian arguments */
SYSCALL_DEFINE1(rtas,struct rtas_args __user *,uargs)1137 SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
1138 {
1139 struct rtas_args args;
1140 unsigned long flags;
1141 char *buff_copy, *errbuf = NULL;
1142 int nargs, nret, token;
1143
1144 if (!capable(CAP_SYS_ADMIN))
1145 return -EPERM;
1146
1147 if (!rtas.entry)
1148 return -EINVAL;
1149
1150 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1151 return -EFAULT;
1152
1153 nargs = be32_to_cpu(args.nargs);
1154 nret = be32_to_cpu(args.nret);
1155 token = be32_to_cpu(args.token);
1156
1157 if (nargs >= ARRAY_SIZE(args.args)
1158 || nret > ARRAY_SIZE(args.args)
1159 || nargs + nret > ARRAY_SIZE(args.args))
1160 return -EINVAL;
1161
1162 /* Copy in args. */
1163 if (copy_from_user(args.args, uargs->args,
1164 nargs * sizeof(rtas_arg_t)) != 0)
1165 return -EFAULT;
1166
1167 if (token == RTAS_UNKNOWN_SERVICE)
1168 return -EINVAL;
1169
1170 args.rets = &args.args[nargs];
1171 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1172
1173 if (block_rtas_call(token, nargs, &args))
1174 return -EINVAL;
1175
1176 /* Need to handle ibm,suspend_me call specially */
1177 if (token == ibm_suspend_me_token) {
1178
1179 /*
1180 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1181 * endian, or at least the hcall within it requires it.
1182 */
1183 int rc = 0;
1184 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1185 | be32_to_cpu(args.args[1]);
1186 rc = rtas_ibm_suspend_me(handle);
1187 if (rc == -EAGAIN)
1188 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1189 else if (rc == -EIO)
1190 args.rets[0] = cpu_to_be32(-1);
1191 else if (rc)
1192 return rc;
1193 goto copy_return;
1194 }
1195
1196 buff_copy = get_errorlog_buffer();
1197
1198 flags = lock_rtas();
1199
1200 rtas.args = args;
1201 enter_rtas(__pa(&rtas.args));
1202 args = rtas.args;
1203
1204 /* A -1 return code indicates that the last command couldn't
1205 be completed due to a hardware error. */
1206 if (be32_to_cpu(args.rets[0]) == -1)
1207 errbuf = __fetch_rtas_last_error(buff_copy);
1208
1209 unlock_rtas(flags);
1210
1211 if (buff_copy) {
1212 if (errbuf)
1213 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1214 kfree(buff_copy);
1215 }
1216
1217 copy_return:
1218 /* Copy out args. */
1219 if (copy_to_user(uargs->args + nargs,
1220 args.args + nargs,
1221 nret * sizeof(rtas_arg_t)) != 0)
1222 return -EFAULT;
1223
1224 return 0;
1225 }
1226
1227 /*
1228 * Call early during boot, before mem init, to retrieve the RTAS
1229 * information from the device-tree and allocate the RMO buffer for userland
1230 * accesses.
1231 */
rtas_initialize(void)1232 void __init rtas_initialize(void)
1233 {
1234 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1235 u32 base, size, entry;
1236 int no_base, no_size, no_entry;
1237 #ifdef CONFIG_PPC_RTAS_FILTER
1238 int i;
1239 #endif
1240
1241 /* Get RTAS dev node and fill up our "rtas" structure with infos
1242 * about it.
1243 */
1244 rtas.dev = of_find_node_by_name(NULL, "rtas");
1245 if (!rtas.dev)
1246 return;
1247
1248 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
1249 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
1250 if (no_base || no_size) {
1251 of_node_put(rtas.dev);
1252 rtas.dev = NULL;
1253 return;
1254 }
1255
1256 rtas.base = base;
1257 rtas.size = size;
1258 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
1259 rtas.entry = no_entry ? rtas.base : entry;
1260
1261 /* If RTAS was found, allocate the RMO buffer for it and look for
1262 * the stop-self token if any
1263 */
1264 #ifdef CONFIG_PPC64
1265 if (firmware_has_feature(FW_FEATURE_LPAR)) {
1266 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1267 ibm_suspend_me_token = rtas_token("ibm,suspend-me");
1268 }
1269 #endif
1270 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_RMOBUF_MAX, PAGE_SIZE,
1271 0, rtas_region);
1272 if (!rtas_rmo_buf)
1273 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
1274 PAGE_SIZE, &rtas_region);
1275
1276 #ifdef CONFIG_RTAS_ERROR_LOGGING
1277 rtas_last_error_token = rtas_token("rtas-last-error");
1278 #endif
1279
1280 #ifdef CONFIG_PPC_RTAS_FILTER
1281 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1282 rtas_filters[i].token = rtas_token(rtas_filters[i].name);
1283 }
1284 #endif
1285 }
1286
early_init_dt_scan_rtas(unsigned long node,const char * uname,int depth,void * data)1287 int __init early_init_dt_scan_rtas(unsigned long node,
1288 const char *uname, int depth, void *data)
1289 {
1290 const u32 *basep, *entryp, *sizep;
1291
1292 if (depth != 1 || strcmp(uname, "rtas") != 0)
1293 return 0;
1294
1295 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1296 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1297 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1298
1299 if (basep && entryp && sizep) {
1300 rtas.base = *basep;
1301 rtas.entry = *entryp;
1302 rtas.size = *sizep;
1303 }
1304
1305 #ifdef CONFIG_UDBG_RTAS_CONSOLE
1306 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1307 if (basep)
1308 rtas_putchar_token = *basep;
1309
1310 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1311 if (basep)
1312 rtas_getchar_token = *basep;
1313
1314 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1315 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1316 udbg_init_rtas_console();
1317
1318 #endif
1319
1320 /* break now */
1321 return 1;
1322 }
1323
1324 static arch_spinlock_t timebase_lock;
1325 static u64 timebase = 0;
1326
rtas_give_timebase(void)1327 void rtas_give_timebase(void)
1328 {
1329 unsigned long flags;
1330
1331 local_irq_save(flags);
1332 hard_irq_disable();
1333 arch_spin_lock(&timebase_lock);
1334 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1335 timebase = get_tb();
1336 arch_spin_unlock(&timebase_lock);
1337
1338 while (timebase)
1339 barrier();
1340 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1341 local_irq_restore(flags);
1342 }
1343
rtas_take_timebase(void)1344 void rtas_take_timebase(void)
1345 {
1346 while (!timebase)
1347 barrier();
1348 arch_spin_lock(&timebase_lock);
1349 set_tb(timebase >> 32, timebase & 0xffffffff);
1350 timebase = 0;
1351 arch_spin_unlock(&timebase_lock);
1352 }
1353