Loading...
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 */
47void enter_rtas(unsigned long);
48
49struct rtas_t rtas = {
50 .lock = __ARCH_SPIN_LOCK_UNLOCKED
51};
52EXPORT_SYMBOL(rtas);
53
54DEFINE_SPINLOCK(rtas_data_buf_lock);
55EXPORT_SYMBOL(rtas_data_buf_lock);
56
57char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
58EXPORT_SYMBOL(rtas_data_buf);
59
60unsigned 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 */
66void (*rtas_flash_term_hook)(int);
67EXPORT_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 */
74static 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
84static 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 */
96static 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
108static 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
132void __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 */
143static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
144static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
145
146static 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
165static 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
178static 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
189void __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
197void 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}
315EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */
316
317int 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}
325EXPORT_SYMBOL(rtas_token);
326
327int rtas_service_present(const char *service)
328{
329 return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
330}
331EXPORT_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 */
339int 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}
354EXPORT_SYMBOL(rtas_get_error_log_max);
355
356
357static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
358static 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 */
366static 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
416static void
417va_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
436void 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
445int 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}
485EXPORT_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 */
490unsigned 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}
506EXPORT_SYMBOL(rtas_busy_delay_time);
507
508/* For an RTAS busy status code, perform the hinted delay. */
509unsigned 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}
520EXPORT_SYMBOL(rtas_busy_delay);
521
522static 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
551int 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}
566EXPORT_SYMBOL(rtas_get_power_level);
567
568int 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}
584EXPORT_SYMBOL(rtas_set_power_level);
585
586int 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}
602EXPORT_SYMBOL(rtas_get_sensor);
603
604int 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
621bool 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}
645EXPORT_SYMBOL(rtas_indicator_present);
646
647int 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}
663EXPORT_SYMBOL(rtas_set_indicator);
664
665/*
666 * Ignoring RTAS extended delay
667 */
668int 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
687void __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
696void 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
706void __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 */
717static char rtas_os_term_buf[2048];
718
719void 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
744static int ibm_suspend_me_token = RTAS_UNKNOWN_SERVICE;
745#ifdef CONFIG_PPC_PSERIES
746static 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
783int 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
789static 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 }
830out:
831 if (atomic_dec_return(&data->working) == 0)
832 complete(data->complete);
833 return rc;
834}
835
836int rtas_suspend_cpu(struct rtas_suspend_me_data *data)
837{
838 return __rtas_suspend_cpu(data, 0);
839}
840
841static void rtas_percpu_suspend_me(void *info)
842{
843 __rtas_suspend_cpu((struct rtas_suspend_me_data *)info, 1);
844}
845
846int 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 */
918int 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 */
952int 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 */
965struct 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/* We assume to be passed big endian arguments */
996SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
997{
998 struct rtas_args args;
999 unsigned long flags;
1000 char *buff_copy, *errbuf = NULL;
1001 int nargs, nret, token;
1002
1003 if (!capable(CAP_SYS_ADMIN))
1004 return -EPERM;
1005
1006 if (!rtas.entry)
1007 return -EINVAL;
1008
1009 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1010 return -EFAULT;
1011
1012 nargs = be32_to_cpu(args.nargs);
1013 nret = be32_to_cpu(args.nret);
1014 token = be32_to_cpu(args.token);
1015
1016 if (nargs >= ARRAY_SIZE(args.args)
1017 || nret > ARRAY_SIZE(args.args)
1018 || nargs + nret > ARRAY_SIZE(args.args))
1019 return -EINVAL;
1020
1021 /* Copy in args. */
1022 if (copy_from_user(args.args, uargs->args,
1023 nargs * sizeof(rtas_arg_t)) != 0)
1024 return -EFAULT;
1025
1026 if (token == RTAS_UNKNOWN_SERVICE)
1027 return -EINVAL;
1028
1029 args.rets = &args.args[nargs];
1030 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1031
1032 /* Need to handle ibm,suspend_me call specially */
1033 if (token == ibm_suspend_me_token) {
1034
1035 /*
1036 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1037 * endian, or at least the hcall within it requires it.
1038 */
1039 int rc = 0;
1040 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1041 | be32_to_cpu(args.args[1]);
1042 rc = rtas_ibm_suspend_me(handle);
1043 if (rc == -EAGAIN)
1044 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1045 else if (rc == -EIO)
1046 args.rets[0] = cpu_to_be32(-1);
1047 else if (rc)
1048 return rc;
1049 goto copy_return;
1050 }
1051
1052 buff_copy = get_errorlog_buffer();
1053
1054 flags = lock_rtas();
1055
1056 rtas.args = args;
1057 enter_rtas(__pa(&rtas.args));
1058 args = rtas.args;
1059
1060 /* A -1 return code indicates that the last command couldn't
1061 be completed due to a hardware error. */
1062 if (be32_to_cpu(args.rets[0]) == -1)
1063 errbuf = __fetch_rtas_last_error(buff_copy);
1064
1065 unlock_rtas(flags);
1066
1067 if (buff_copy) {
1068 if (errbuf)
1069 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1070 kfree(buff_copy);
1071 }
1072
1073 copy_return:
1074 /* Copy out args. */
1075 if (copy_to_user(uargs->args + nargs,
1076 args.args + nargs,
1077 nret * sizeof(rtas_arg_t)) != 0)
1078 return -EFAULT;
1079
1080 return 0;
1081}
1082
1083/*
1084 * Call early during boot, before mem init, to retrieve the RTAS
1085 * information from the device-tree and allocate the RMO buffer for userland
1086 * accesses.
1087 */
1088void __init rtas_initialize(void)
1089{
1090 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1091 u32 base, size, entry;
1092 int no_base, no_size, no_entry;
1093
1094 /* Get RTAS dev node and fill up our "rtas" structure with infos
1095 * about it.
1096 */
1097 rtas.dev = of_find_node_by_name(NULL, "rtas");
1098 if (!rtas.dev)
1099 return;
1100
1101 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
1102 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
1103 if (no_base || no_size) {
1104 of_node_put(rtas.dev);
1105 rtas.dev = NULL;
1106 return;
1107 }
1108
1109 rtas.base = base;
1110 rtas.size = size;
1111 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
1112 rtas.entry = no_entry ? rtas.base : entry;
1113
1114 /* If RTAS was found, allocate the RMO buffer for it and look for
1115 * the stop-self token if any
1116 */
1117#ifdef CONFIG_PPC64
1118 if (firmware_has_feature(FW_FEATURE_LPAR)) {
1119 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1120 ibm_suspend_me_token = rtas_token("ibm,suspend-me");
1121 }
1122#endif
1123 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_RMOBUF_MAX, PAGE_SIZE,
1124 0, rtas_region);
1125 if (!rtas_rmo_buf)
1126 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
1127 PAGE_SIZE, &rtas_region);
1128
1129#ifdef CONFIG_RTAS_ERROR_LOGGING
1130 rtas_last_error_token = rtas_token("rtas-last-error");
1131#endif
1132}
1133
1134int __init early_init_dt_scan_rtas(unsigned long node,
1135 const char *uname, int depth, void *data)
1136{
1137 const u32 *basep, *entryp, *sizep;
1138
1139 if (depth != 1 || strcmp(uname, "rtas") != 0)
1140 return 0;
1141
1142 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1143 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1144 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1145
1146 if (basep && entryp && sizep) {
1147 rtas.base = *basep;
1148 rtas.entry = *entryp;
1149 rtas.size = *sizep;
1150 }
1151
1152#ifdef CONFIG_UDBG_RTAS_CONSOLE
1153 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1154 if (basep)
1155 rtas_putchar_token = *basep;
1156
1157 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1158 if (basep)
1159 rtas_getchar_token = *basep;
1160
1161 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1162 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1163 udbg_init_rtas_console();
1164
1165#endif
1166
1167 /* break now */
1168 return 1;
1169}
1170
1171static arch_spinlock_t timebase_lock;
1172static u64 timebase = 0;
1173
1174void rtas_give_timebase(void)
1175{
1176 unsigned long flags;
1177
1178 local_irq_save(flags);
1179 hard_irq_disable();
1180 arch_spin_lock(&timebase_lock);
1181 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1182 timebase = get_tb();
1183 arch_spin_unlock(&timebase_lock);
1184
1185 while (timebase)
1186 barrier();
1187 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1188 local_irq_restore(flags);
1189}
1190
1191void rtas_take_timebase(void)
1192{
1193 while (!timebase)
1194 barrier();
1195 arch_spin_lock(&timebase_lock);
1196 set_tb(timebase >> 32, timebase & 0xffffffff);
1197 timebase = 0;
1198 arch_spin_unlock(&timebase_lock);
1199}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Procedures for interfacing to the RTAS on CHRP machines.
5 *
6 * Peter Bergner, IBM March 2001.
7 * Copyright (C) 2001 IBM.
8 */
9
10#define pr_fmt(fmt) "rtas: " fmt
11
12#include <linux/bsearch.h>
13#include <linux/capability.h>
14#include <linux/delay.h>
15#include <linux/export.h>
16#include <linux/init.h>
17#include <linux/kconfig.h>
18#include <linux/kernel.h>
19#include <linux/lockdep.h>
20#include <linux/memblock.h>
21#include <linux/mutex.h>
22#include <linux/nospec.h>
23#include <linux/of.h>
24#include <linux/of_fdt.h>
25#include <linux/reboot.h>
26#include <linux/sched.h>
27#include <linux/security.h>
28#include <linux/slab.h>
29#include <linux/spinlock.h>
30#include <linux/stdarg.h>
31#include <linux/syscalls.h>
32#include <linux/types.h>
33#include <linux/uaccess.h>
34#include <linux/xarray.h>
35
36#include <asm/delay.h>
37#include <asm/firmware.h>
38#include <asm/interrupt.h>
39#include <asm/machdep.h>
40#include <asm/mmu.h>
41#include <asm/page.h>
42#include <asm/rtas-work-area.h>
43#include <asm/rtas.h>
44#include <asm/time.h>
45#include <asm/trace.h>
46#include <asm/udbg.h>
47
48struct rtas_filter {
49 /* Indexes into the args buffer, -1 if not used */
50 const int buf_idx1;
51 const int size_idx1;
52 const int buf_idx2;
53 const int size_idx2;
54 /*
55 * Assumed buffer size per the spec if the function does not
56 * have a size parameter, e.g. ibm,errinjct. 0 if unused.
57 */
58 const int fixed_size;
59};
60
61/**
62 * struct rtas_function - Descriptor for RTAS functions.
63 *
64 * @token: Value of @name if it exists under the /rtas node.
65 * @name: Function name.
66 * @filter: If non-NULL, invoking this function via the rtas syscall is
67 * generally allowed, and @filter describes constraints on the
68 * arguments. See also @banned_for_syscall_on_le.
69 * @banned_for_syscall_on_le: Set when call via sys_rtas is generally allowed
70 * but specifically restricted on ppc64le. Such
71 * functions are believed to have no users on
72 * ppc64le, and we want to keep it that way. It does
73 * not make sense for this to be set when @filter
74 * is NULL.
75 * @lock: Pointer to an optional dedicated per-function mutex. This
76 * should be set for functions that require multiple calls in
77 * sequence to complete a single operation, and such sequences
78 * will disrupt each other if allowed to interleave. Users of
79 * this function are required to hold the associated lock for
80 * the duration of the call sequence. Add an explanatory
81 * comment to the function table entry if setting this member.
82 */
83struct rtas_function {
84 s32 token;
85 const bool banned_for_syscall_on_le:1;
86 const char * const name;
87 const struct rtas_filter *filter;
88 struct mutex *lock;
89};
90
91/*
92 * Per-function locks for sequence-based RTAS functions.
93 */
94static DEFINE_MUTEX(rtas_ibm_activate_firmware_lock);
95static DEFINE_MUTEX(rtas_ibm_get_dynamic_sensor_state_lock);
96static DEFINE_MUTEX(rtas_ibm_get_indices_lock);
97static DEFINE_MUTEX(rtas_ibm_lpar_perftools_lock);
98static DEFINE_MUTEX(rtas_ibm_physical_attestation_lock);
99static DEFINE_MUTEX(rtas_ibm_set_dynamic_indicator_lock);
100DEFINE_MUTEX(rtas_ibm_get_vpd_lock);
101
102static struct rtas_function rtas_function_table[] __ro_after_init = {
103 [RTAS_FNIDX__CHECK_EXCEPTION] = {
104 .name = "check-exception",
105 },
106 [RTAS_FNIDX__DISPLAY_CHARACTER] = {
107 .name = "display-character",
108 .filter = &(const struct rtas_filter) {
109 .buf_idx1 = -1, .size_idx1 = -1,
110 .buf_idx2 = -1, .size_idx2 = -1,
111 },
112 },
113 [RTAS_FNIDX__EVENT_SCAN] = {
114 .name = "event-scan",
115 },
116 [RTAS_FNIDX__FREEZE_TIME_BASE] = {
117 .name = "freeze-time-base",
118 },
119 [RTAS_FNIDX__GET_POWER_LEVEL] = {
120 .name = "get-power-level",
121 .filter = &(const struct rtas_filter) {
122 .buf_idx1 = -1, .size_idx1 = -1,
123 .buf_idx2 = -1, .size_idx2 = -1,
124 },
125 },
126 [RTAS_FNIDX__GET_SENSOR_STATE] = {
127 .name = "get-sensor-state",
128 .filter = &(const struct rtas_filter) {
129 .buf_idx1 = -1, .size_idx1 = -1,
130 .buf_idx2 = -1, .size_idx2 = -1,
131 },
132 },
133 [RTAS_FNIDX__GET_TERM_CHAR] = {
134 .name = "get-term-char",
135 },
136 [RTAS_FNIDX__GET_TIME_OF_DAY] = {
137 .name = "get-time-of-day",
138 .filter = &(const struct rtas_filter) {
139 .buf_idx1 = -1, .size_idx1 = -1,
140 .buf_idx2 = -1, .size_idx2 = -1,
141 },
142 },
143 [RTAS_FNIDX__IBM_ACTIVATE_FIRMWARE] = {
144 .name = "ibm,activate-firmware",
145 .filter = &(const struct rtas_filter) {
146 .buf_idx1 = -1, .size_idx1 = -1,
147 .buf_idx2 = -1, .size_idx2 = -1,
148 },
149 /*
150 * PAPR+ as of v2.13 doesn't explicitly impose any
151 * restriction, but this typically requires multiple
152 * calls before success, and there's no reason to
153 * allow sequences to interleave.
154 */
155 .lock = &rtas_ibm_activate_firmware_lock,
156 },
157 [RTAS_FNIDX__IBM_CBE_START_PTCAL] = {
158 .name = "ibm,cbe-start-ptcal",
159 },
160 [RTAS_FNIDX__IBM_CBE_STOP_PTCAL] = {
161 .name = "ibm,cbe-stop-ptcal",
162 },
163 [RTAS_FNIDX__IBM_CHANGE_MSI] = {
164 .name = "ibm,change-msi",
165 },
166 [RTAS_FNIDX__IBM_CLOSE_ERRINJCT] = {
167 .name = "ibm,close-errinjct",
168 .filter = &(const struct rtas_filter) {
169 .buf_idx1 = -1, .size_idx1 = -1,
170 .buf_idx2 = -1, .size_idx2 = -1,
171 },
172 },
173 [RTAS_FNIDX__IBM_CONFIGURE_BRIDGE] = {
174 .name = "ibm,configure-bridge",
175 },
176 [RTAS_FNIDX__IBM_CONFIGURE_CONNECTOR] = {
177 .name = "ibm,configure-connector",
178 .filter = &(const struct rtas_filter) {
179 .buf_idx1 = 0, .size_idx1 = -1,
180 .buf_idx2 = 1, .size_idx2 = -1,
181 .fixed_size = 4096,
182 },
183 },
184 [RTAS_FNIDX__IBM_CONFIGURE_KERNEL_DUMP] = {
185 .name = "ibm,configure-kernel-dump",
186 },
187 [RTAS_FNIDX__IBM_CONFIGURE_PE] = {
188 .name = "ibm,configure-pe",
189 },
190 [RTAS_FNIDX__IBM_CREATE_PE_DMA_WINDOW] = {
191 .name = "ibm,create-pe-dma-window",
192 },
193 [RTAS_FNIDX__IBM_DISPLAY_MESSAGE] = {
194 .name = "ibm,display-message",
195 .filter = &(const struct rtas_filter) {
196 .buf_idx1 = 0, .size_idx1 = -1,
197 .buf_idx2 = -1, .size_idx2 = -1,
198 },
199 },
200 [RTAS_FNIDX__IBM_ERRINJCT] = {
201 .name = "ibm,errinjct",
202 .filter = &(const struct rtas_filter) {
203 .buf_idx1 = 2, .size_idx1 = -1,
204 .buf_idx2 = -1, .size_idx2 = -1,
205 .fixed_size = 1024,
206 },
207 },
208 [RTAS_FNIDX__IBM_EXTI2C] = {
209 .name = "ibm,exti2c",
210 },
211 [RTAS_FNIDX__IBM_GET_CONFIG_ADDR_INFO] = {
212 .name = "ibm,get-config-addr-info",
213 },
214 [RTAS_FNIDX__IBM_GET_CONFIG_ADDR_INFO2] = {
215 .name = "ibm,get-config-addr-info2",
216 .filter = &(const struct rtas_filter) {
217 .buf_idx1 = -1, .size_idx1 = -1,
218 .buf_idx2 = -1, .size_idx2 = -1,
219 },
220 },
221 [RTAS_FNIDX__IBM_GET_DYNAMIC_SENSOR_STATE] = {
222 .name = "ibm,get-dynamic-sensor-state",
223 .filter = &(const struct rtas_filter) {
224 .buf_idx1 = 1, .size_idx1 = -1,
225 .buf_idx2 = -1, .size_idx2 = -1,
226 },
227 /*
228 * PAPR+ v2.13 R1–7.3.19–3 is explicit that the OS
229 * must not call ibm,get-dynamic-sensor-state with
230 * different inputs until a non-retry status has been
231 * returned.
232 */
233 .lock = &rtas_ibm_get_dynamic_sensor_state_lock,
234 },
235 [RTAS_FNIDX__IBM_GET_INDICES] = {
236 .name = "ibm,get-indices",
237 .filter = &(const struct rtas_filter) {
238 .buf_idx1 = 2, .size_idx1 = 3,
239 .buf_idx2 = -1, .size_idx2 = -1,
240 },
241 /*
242 * PAPR+ v2.13 R1–7.3.17–2 says that the OS must not
243 * interleave ibm,get-indices call sequences with
244 * different inputs.
245 */
246 .lock = &rtas_ibm_get_indices_lock,
247 },
248 [RTAS_FNIDX__IBM_GET_RIO_TOPOLOGY] = {
249 .name = "ibm,get-rio-topology",
250 },
251 [RTAS_FNIDX__IBM_GET_SYSTEM_PARAMETER] = {
252 .name = "ibm,get-system-parameter",
253 .filter = &(const struct rtas_filter) {
254 .buf_idx1 = 1, .size_idx1 = 2,
255 .buf_idx2 = -1, .size_idx2 = -1,
256 },
257 },
258 [RTAS_FNIDX__IBM_GET_VPD] = {
259 .name = "ibm,get-vpd",
260 .filter = &(const struct rtas_filter) {
261 .buf_idx1 = 0, .size_idx1 = -1,
262 .buf_idx2 = 1, .size_idx2 = 2,
263 },
264 /*
265 * PAPR+ v2.13 R1–7.3.20–4 indicates that sequences
266 * should not be allowed to interleave.
267 */
268 .lock = &rtas_ibm_get_vpd_lock,
269 },
270 [RTAS_FNIDX__IBM_GET_XIVE] = {
271 .name = "ibm,get-xive",
272 },
273 [RTAS_FNIDX__IBM_INT_OFF] = {
274 .name = "ibm,int-off",
275 },
276 [RTAS_FNIDX__IBM_INT_ON] = {
277 .name = "ibm,int-on",
278 },
279 [RTAS_FNIDX__IBM_IO_QUIESCE_ACK] = {
280 .name = "ibm,io-quiesce-ack",
281 },
282 [RTAS_FNIDX__IBM_LPAR_PERFTOOLS] = {
283 .name = "ibm,lpar-perftools",
284 .filter = &(const struct rtas_filter) {
285 .buf_idx1 = 2, .size_idx1 = 3,
286 .buf_idx2 = -1, .size_idx2 = -1,
287 },
288 /*
289 * PAPR+ v2.13 R1–7.3.26–6 says the OS should allow
290 * only one call sequence in progress at a time.
291 */
292 .lock = &rtas_ibm_lpar_perftools_lock,
293 },
294 [RTAS_FNIDX__IBM_MANAGE_FLASH_IMAGE] = {
295 .name = "ibm,manage-flash-image",
296 },
297 [RTAS_FNIDX__IBM_MANAGE_STORAGE_PRESERVATION] = {
298 .name = "ibm,manage-storage-preservation",
299 },
300 [RTAS_FNIDX__IBM_NMI_INTERLOCK] = {
301 .name = "ibm,nmi-interlock",
302 },
303 [RTAS_FNIDX__IBM_NMI_REGISTER] = {
304 .name = "ibm,nmi-register",
305 },
306 [RTAS_FNIDX__IBM_OPEN_ERRINJCT] = {
307 .name = "ibm,open-errinjct",
308 .filter = &(const struct rtas_filter) {
309 .buf_idx1 = -1, .size_idx1 = -1,
310 .buf_idx2 = -1, .size_idx2 = -1,
311 },
312 },
313 [RTAS_FNIDX__IBM_OPEN_SRIOV_ALLOW_UNFREEZE] = {
314 .name = "ibm,open-sriov-allow-unfreeze",
315 },
316 [RTAS_FNIDX__IBM_OPEN_SRIOV_MAP_PE_NUMBER] = {
317 .name = "ibm,open-sriov-map-pe-number",
318 },
319 [RTAS_FNIDX__IBM_OS_TERM] = {
320 .name = "ibm,os-term",
321 },
322 [RTAS_FNIDX__IBM_PARTNER_CONTROL] = {
323 .name = "ibm,partner-control",
324 },
325 [RTAS_FNIDX__IBM_PHYSICAL_ATTESTATION] = {
326 .name = "ibm,physical-attestation",
327 .filter = &(const struct rtas_filter) {
328 .buf_idx1 = 0, .size_idx1 = 1,
329 .buf_idx2 = -1, .size_idx2 = -1,
330 },
331 /*
332 * This follows a sequence-based pattern similar to
333 * ibm,get-vpd et al. Since PAPR+ restricts
334 * interleaving call sequences for other functions of
335 * this style, assume the restriction applies here,
336 * even though it's not explicit in the spec.
337 */
338 .lock = &rtas_ibm_physical_attestation_lock,
339 },
340 [RTAS_FNIDX__IBM_PLATFORM_DUMP] = {
341 .name = "ibm,platform-dump",
342 .filter = &(const struct rtas_filter) {
343 .buf_idx1 = 4, .size_idx1 = 5,
344 .buf_idx2 = -1, .size_idx2 = -1,
345 },
346 /*
347 * PAPR+ v2.13 7.3.3.4.1 indicates that concurrent
348 * sequences of ibm,platform-dump are allowed if they
349 * are operating on different dump tags. So leave the
350 * lock pointer unset for now. This may need
351 * reconsideration if kernel-internal users appear.
352 */
353 },
354 [RTAS_FNIDX__IBM_POWER_OFF_UPS] = {
355 .name = "ibm,power-off-ups",
356 },
357 [RTAS_FNIDX__IBM_QUERY_INTERRUPT_SOURCE_NUMBER] = {
358 .name = "ibm,query-interrupt-source-number",
359 },
360 [RTAS_FNIDX__IBM_QUERY_PE_DMA_WINDOW] = {
361 .name = "ibm,query-pe-dma-window",
362 },
363 [RTAS_FNIDX__IBM_READ_PCI_CONFIG] = {
364 .name = "ibm,read-pci-config",
365 },
366 [RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE] = {
367 .name = "ibm,read-slot-reset-state",
368 .filter = &(const struct rtas_filter) {
369 .buf_idx1 = -1, .size_idx1 = -1,
370 .buf_idx2 = -1, .size_idx2 = -1,
371 },
372 },
373 [RTAS_FNIDX__IBM_READ_SLOT_RESET_STATE2] = {
374 .name = "ibm,read-slot-reset-state2",
375 },
376 [RTAS_FNIDX__IBM_REMOVE_PE_DMA_WINDOW] = {
377 .name = "ibm,remove-pe-dma-window",
378 },
379 [RTAS_FNIDX__IBM_RESET_PE_DMA_WINDOW] = {
380 /*
381 * Note: PAPR+ v2.13 7.3.31.4.1 spells this as
382 * "ibm,reset-pe-dma-windows" (plural), but RTAS
383 * implementations use the singular form in practice.
384 */
385 .name = "ibm,reset-pe-dma-window",
386 },
387 [RTAS_FNIDX__IBM_SCAN_LOG_DUMP] = {
388 .name = "ibm,scan-log-dump",
389 .filter = &(const struct rtas_filter) {
390 .buf_idx1 = 0, .size_idx1 = 1,
391 .buf_idx2 = -1, .size_idx2 = -1,
392 },
393 },
394 [RTAS_FNIDX__IBM_SET_DYNAMIC_INDICATOR] = {
395 .name = "ibm,set-dynamic-indicator",
396 .filter = &(const struct rtas_filter) {
397 .buf_idx1 = 2, .size_idx1 = -1,
398 .buf_idx2 = -1, .size_idx2 = -1,
399 },
400 /*
401 * PAPR+ v2.13 R1–7.3.18–3 says the OS must not call
402 * this function with different inputs until a
403 * non-retry status has been returned.
404 */
405 .lock = &rtas_ibm_set_dynamic_indicator_lock,
406 },
407 [RTAS_FNIDX__IBM_SET_EEH_OPTION] = {
408 .name = "ibm,set-eeh-option",
409 .filter = &(const struct rtas_filter) {
410 .buf_idx1 = -1, .size_idx1 = -1,
411 .buf_idx2 = -1, .size_idx2 = -1,
412 },
413 },
414 [RTAS_FNIDX__IBM_SET_SLOT_RESET] = {
415 .name = "ibm,set-slot-reset",
416 },
417 [RTAS_FNIDX__IBM_SET_SYSTEM_PARAMETER] = {
418 .name = "ibm,set-system-parameter",
419 .filter = &(const struct rtas_filter) {
420 .buf_idx1 = 1, .size_idx1 = -1,
421 .buf_idx2 = -1, .size_idx2 = -1,
422 },
423 },
424 [RTAS_FNIDX__IBM_SET_XIVE] = {
425 .name = "ibm,set-xive",
426 },
427 [RTAS_FNIDX__IBM_SLOT_ERROR_DETAIL] = {
428 .name = "ibm,slot-error-detail",
429 },
430 [RTAS_FNIDX__IBM_SUSPEND_ME] = {
431 .name = "ibm,suspend-me",
432 .banned_for_syscall_on_le = true,
433 .filter = &(const struct rtas_filter) {
434 .buf_idx1 = -1, .size_idx1 = -1,
435 .buf_idx2 = -1, .size_idx2 = -1,
436 },
437 },
438 [RTAS_FNIDX__IBM_TUNE_DMA_PARMS] = {
439 .name = "ibm,tune-dma-parms",
440 },
441 [RTAS_FNIDX__IBM_UPDATE_FLASH_64_AND_REBOOT] = {
442 .name = "ibm,update-flash-64-and-reboot",
443 },
444 [RTAS_FNIDX__IBM_UPDATE_NODES] = {
445 .name = "ibm,update-nodes",
446 .banned_for_syscall_on_le = true,
447 .filter = &(const struct rtas_filter) {
448 .buf_idx1 = 0, .size_idx1 = -1,
449 .buf_idx2 = -1, .size_idx2 = -1,
450 .fixed_size = 4096,
451 },
452 },
453 [RTAS_FNIDX__IBM_UPDATE_PROPERTIES] = {
454 .name = "ibm,update-properties",
455 .banned_for_syscall_on_le = true,
456 .filter = &(const struct rtas_filter) {
457 .buf_idx1 = 0, .size_idx1 = -1,
458 .buf_idx2 = -1, .size_idx2 = -1,
459 .fixed_size = 4096,
460 },
461 },
462 [RTAS_FNIDX__IBM_VALIDATE_FLASH_IMAGE] = {
463 .name = "ibm,validate-flash-image",
464 },
465 [RTAS_FNIDX__IBM_WRITE_PCI_CONFIG] = {
466 .name = "ibm,write-pci-config",
467 },
468 [RTAS_FNIDX__NVRAM_FETCH] = {
469 .name = "nvram-fetch",
470 },
471 [RTAS_FNIDX__NVRAM_STORE] = {
472 .name = "nvram-store",
473 },
474 [RTAS_FNIDX__POWER_OFF] = {
475 .name = "power-off",
476 },
477 [RTAS_FNIDX__PUT_TERM_CHAR] = {
478 .name = "put-term-char",
479 },
480 [RTAS_FNIDX__QUERY_CPU_STOPPED_STATE] = {
481 .name = "query-cpu-stopped-state",
482 },
483 [RTAS_FNIDX__READ_PCI_CONFIG] = {
484 .name = "read-pci-config",
485 },
486 [RTAS_FNIDX__RTAS_LAST_ERROR] = {
487 .name = "rtas-last-error",
488 },
489 [RTAS_FNIDX__SET_INDICATOR] = {
490 .name = "set-indicator",
491 .filter = &(const struct rtas_filter) {
492 .buf_idx1 = -1, .size_idx1 = -1,
493 .buf_idx2 = -1, .size_idx2 = -1,
494 },
495 },
496 [RTAS_FNIDX__SET_POWER_LEVEL] = {
497 .name = "set-power-level",
498 .filter = &(const struct rtas_filter) {
499 .buf_idx1 = -1, .size_idx1 = -1,
500 .buf_idx2 = -1, .size_idx2 = -1,
501 },
502 },
503 [RTAS_FNIDX__SET_TIME_FOR_POWER_ON] = {
504 .name = "set-time-for-power-on",
505 .filter = &(const struct rtas_filter) {
506 .buf_idx1 = -1, .size_idx1 = -1,
507 .buf_idx2 = -1, .size_idx2 = -1,
508 },
509 },
510 [RTAS_FNIDX__SET_TIME_OF_DAY] = {
511 .name = "set-time-of-day",
512 .filter = &(const struct rtas_filter) {
513 .buf_idx1 = -1, .size_idx1 = -1,
514 .buf_idx2 = -1, .size_idx2 = -1,
515 },
516 },
517 [RTAS_FNIDX__START_CPU] = {
518 .name = "start-cpu",
519 },
520 [RTAS_FNIDX__STOP_SELF] = {
521 .name = "stop-self",
522 },
523 [RTAS_FNIDX__SYSTEM_REBOOT] = {
524 .name = "system-reboot",
525 },
526 [RTAS_FNIDX__THAW_TIME_BASE] = {
527 .name = "thaw-time-base",
528 },
529 [RTAS_FNIDX__WRITE_PCI_CONFIG] = {
530 .name = "write-pci-config",
531 },
532};
533
534#define for_each_rtas_function(funcp) \
535 for (funcp = &rtas_function_table[0]; \
536 funcp < &rtas_function_table[ARRAY_SIZE(rtas_function_table)]; \
537 ++funcp)
538
539/*
540 * Nearly all RTAS calls need to be serialized. All uses of the
541 * default rtas_args block must hold rtas_lock.
542 *
543 * Exceptions to the RTAS serialization requirement (e.g. stop-self)
544 * must use a separate rtas_args structure.
545 */
546static DEFINE_RAW_SPINLOCK(rtas_lock);
547static struct rtas_args rtas_args;
548
549/**
550 * rtas_function_token() - RTAS function token lookup.
551 * @handle: Function handle, e.g. RTAS_FN_EVENT_SCAN.
552 *
553 * Context: Any context.
554 * Return: the token value for the function if implemented by this platform,
555 * otherwise RTAS_UNKNOWN_SERVICE.
556 */
557s32 rtas_function_token(const rtas_fn_handle_t handle)
558{
559 const size_t index = handle.index;
560 const bool out_of_bounds = index >= ARRAY_SIZE(rtas_function_table);
561
562 if (WARN_ONCE(out_of_bounds, "invalid function index %zu", index))
563 return RTAS_UNKNOWN_SERVICE;
564 /*
565 * Various drivers attempt token lookups on non-RTAS
566 * platforms.
567 */
568 if (!rtas.dev)
569 return RTAS_UNKNOWN_SERVICE;
570
571 return rtas_function_table[index].token;
572}
573EXPORT_SYMBOL_GPL(rtas_function_token);
574
575static int rtas_function_cmp(const void *a, const void *b)
576{
577 const struct rtas_function *f1 = a;
578 const struct rtas_function *f2 = b;
579
580 return strcmp(f1->name, f2->name);
581}
582
583/*
584 * Boot-time initialization of the function table needs the lookup to
585 * return a non-const-qualified object. Use rtas_name_to_function()
586 * in all other contexts.
587 */
588static struct rtas_function *__rtas_name_to_function(const char *name)
589{
590 const struct rtas_function key = {
591 .name = name,
592 };
593 struct rtas_function *found;
594
595 found = bsearch(&key, rtas_function_table, ARRAY_SIZE(rtas_function_table),
596 sizeof(rtas_function_table[0]), rtas_function_cmp);
597
598 return found;
599}
600
601static const struct rtas_function *rtas_name_to_function(const char *name)
602{
603 return __rtas_name_to_function(name);
604}
605
606static DEFINE_XARRAY(rtas_token_to_function_xarray);
607
608static int __init rtas_token_to_function_xarray_init(void)
609{
610 const struct rtas_function *func;
611 int err = 0;
612
613 for_each_rtas_function(func) {
614 const s32 token = func->token;
615
616 if (token == RTAS_UNKNOWN_SERVICE)
617 continue;
618
619 err = xa_err(xa_store(&rtas_token_to_function_xarray,
620 token, (void *)func, GFP_KERNEL));
621 if (err)
622 break;
623 }
624
625 return err;
626}
627arch_initcall(rtas_token_to_function_xarray_init);
628
629/*
630 * For use by sys_rtas(), where the token value is provided by user
631 * space and we don't want to warn on failed lookups.
632 */
633static const struct rtas_function *rtas_token_to_function_untrusted(s32 token)
634{
635 return xa_load(&rtas_token_to_function_xarray, token);
636}
637
638/*
639 * Reverse lookup for deriving the function descriptor from a
640 * known-good token value in contexts where the former is not already
641 * available. @token must be valid, e.g. derived from the result of a
642 * prior lookup against the function table.
643 */
644static const struct rtas_function *rtas_token_to_function(s32 token)
645{
646 const struct rtas_function *func;
647
648 if (WARN_ONCE(token < 0, "invalid token %d", token))
649 return NULL;
650
651 func = rtas_token_to_function_untrusted(token);
652 if (func)
653 return func;
654 /*
655 * Fall back to linear scan in case the reverse mapping hasn't
656 * been initialized yet.
657 */
658 if (xa_empty(&rtas_token_to_function_xarray)) {
659 for_each_rtas_function(func) {
660 if (func->token == token)
661 return func;
662 }
663 }
664
665 WARN_ONCE(true, "unexpected failed lookup for token %d", token);
666 return NULL;
667}
668
669/* This is here deliberately so it's only used in this file */
670void enter_rtas(unsigned long);
671
672static void __do_enter_rtas(struct rtas_args *args)
673{
674 enter_rtas(__pa(args));
675 srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
676}
677
678static void __do_enter_rtas_trace(struct rtas_args *args)
679{
680 const struct rtas_function *func = rtas_token_to_function(be32_to_cpu(args->token));
681
682 /*
683 * If there is a per-function lock, it must be held by the
684 * caller.
685 */
686 if (func->lock)
687 lockdep_assert_held(func->lock);
688
689 if (args == &rtas_args)
690 lockdep_assert_held(&rtas_lock);
691
692 trace_rtas_input(args, func->name);
693 trace_rtas_ll_entry(args);
694
695 __do_enter_rtas(args);
696
697 trace_rtas_ll_exit(args);
698 trace_rtas_output(args, func->name);
699}
700
701static void do_enter_rtas(struct rtas_args *args)
702{
703 const unsigned long msr = mfmsr();
704 /*
705 * Situations where we want to skip any active tracepoints for
706 * safety reasons:
707 *
708 * 1. The last code executed on an offline CPU as it stops,
709 * i.e. we're about to call stop-self. The tracepoints'
710 * function name lookup uses xarray, which uses RCU, which
711 * isn't valid to call on an offline CPU. Any events
712 * emitted on an offline CPU will be discarded anyway.
713 *
714 * 2. In real mode, as when invoking ibm,nmi-interlock from
715 * the pseries MCE handler. We cannot count on trace
716 * buffers or the entries in rtas_token_to_function_xarray
717 * to be contained in the RMO.
718 */
719 const unsigned long mask = MSR_IR | MSR_DR;
720 const bool can_trace = likely(cpu_online(raw_smp_processor_id()) &&
721 (msr & mask) == mask);
722 /*
723 * Make sure MSR[RI] is currently enabled as it will be forced later
724 * in enter_rtas.
725 */
726 BUG_ON(!(msr & MSR_RI));
727
728 BUG_ON(!irqs_disabled());
729
730 hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */
731
732 if (can_trace)
733 __do_enter_rtas_trace(args);
734 else
735 __do_enter_rtas(args);
736}
737
738struct rtas_t rtas;
739
740DEFINE_SPINLOCK(rtas_data_buf_lock);
741EXPORT_SYMBOL_GPL(rtas_data_buf_lock);
742
743char rtas_data_buf[RTAS_DATA_BUF_SIZE] __aligned(SZ_4K);
744EXPORT_SYMBOL_GPL(rtas_data_buf);
745
746unsigned long rtas_rmo_buf;
747
748/*
749 * If non-NULL, this gets called when the kernel terminates.
750 * This is done like this so rtas_flash can be a module.
751 */
752void (*rtas_flash_term_hook)(int);
753EXPORT_SYMBOL_GPL(rtas_flash_term_hook);
754
755/*
756 * call_rtas_display_status and call_rtas_display_status_delay
757 * are designed only for very early low-level debugging, which
758 * is why the token is hard-coded to 10.
759 */
760static void call_rtas_display_status(unsigned char c)
761{
762 unsigned long flags;
763
764 if (!rtas.base)
765 return;
766
767 raw_spin_lock_irqsave(&rtas_lock, flags);
768 rtas_call_unlocked(&rtas_args, 10, 1, 1, NULL, c);
769 raw_spin_unlock_irqrestore(&rtas_lock, flags);
770}
771
772static void call_rtas_display_status_delay(char c)
773{
774 static int pending_newline = 0; /* did last write end with unprinted newline? */
775 static int width = 16;
776
777 if (c == '\n') {
778 while (width-- > 0)
779 call_rtas_display_status(' ');
780 width = 16;
781 mdelay(500);
782 pending_newline = 1;
783 } else {
784 if (pending_newline) {
785 call_rtas_display_status('\r');
786 call_rtas_display_status('\n');
787 }
788 pending_newline = 0;
789 if (width--) {
790 call_rtas_display_status(c);
791 udelay(10000);
792 }
793 }
794}
795
796void __init udbg_init_rtas_panel(void)
797{
798 udbg_putc = call_rtas_display_status_delay;
799}
800
801#ifdef CONFIG_UDBG_RTAS_CONSOLE
802
803/* If you think you're dying before early_init_dt_scan_rtas() does its
804 * work, you can hard code the token values for your firmware here and
805 * hardcode rtas.base/entry etc.
806 */
807static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
808static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
809
810static void udbg_rtascon_putc(char c)
811{
812 int tries;
813
814 if (!rtas.base)
815 return;
816
817 /* Add CRs before LFs */
818 if (c == '\n')
819 udbg_rtascon_putc('\r');
820
821 /* if there is more than one character to be displayed, wait a bit */
822 for (tries = 0; tries < 16; tries++) {
823 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
824 break;
825 udelay(1000);
826 }
827}
828
829static int udbg_rtascon_getc_poll(void)
830{
831 int c;
832
833 if (!rtas.base)
834 return -1;
835
836 if (rtas_call(rtas_getchar_token, 0, 2, &c))
837 return -1;
838
839 return c;
840}
841
842static int udbg_rtascon_getc(void)
843{
844 int c;
845
846 while ((c = udbg_rtascon_getc_poll()) == -1)
847 ;
848
849 return c;
850}
851
852
853void __init udbg_init_rtas_console(void)
854{
855 udbg_putc = udbg_rtascon_putc;
856 udbg_getc = udbg_rtascon_getc;
857 udbg_getc_poll = udbg_rtascon_getc_poll;
858}
859#endif /* CONFIG_UDBG_RTAS_CONSOLE */
860
861void rtas_progress(char *s, unsigned short hex)
862{
863 struct device_node *root;
864 int width;
865 const __be32 *p;
866 char *os;
867 static int display_character, set_indicator;
868 static int display_width, display_lines, form_feed;
869 static const int *row_width;
870 static DEFINE_SPINLOCK(progress_lock);
871 static int current_line;
872 static int pending_newline = 0; /* did last write end with unprinted newline? */
873
874 if (!rtas.base)
875 return;
876
877 if (display_width == 0) {
878 display_width = 0x10;
879 if ((root = of_find_node_by_path("/rtas"))) {
880 if ((p = of_get_property(root,
881 "ibm,display-line-length", NULL)))
882 display_width = be32_to_cpu(*p);
883 if ((p = of_get_property(root,
884 "ibm,form-feed", NULL)))
885 form_feed = be32_to_cpu(*p);
886 if ((p = of_get_property(root,
887 "ibm,display-number-of-lines", NULL)))
888 display_lines = be32_to_cpu(*p);
889 row_width = of_get_property(root,
890 "ibm,display-truncation-length", NULL);
891 of_node_put(root);
892 }
893 display_character = rtas_function_token(RTAS_FN_DISPLAY_CHARACTER);
894 set_indicator = rtas_function_token(RTAS_FN_SET_INDICATOR);
895 }
896
897 if (display_character == RTAS_UNKNOWN_SERVICE) {
898 /* use hex display if available */
899 if (set_indicator != RTAS_UNKNOWN_SERVICE)
900 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
901 return;
902 }
903
904 spin_lock(&progress_lock);
905
906 /*
907 * Last write ended with newline, but we didn't print it since
908 * it would just clear the bottom line of output. Print it now
909 * instead.
910 *
911 * If no newline is pending and form feed is supported, clear the
912 * display with a form feed; otherwise, print a CR to start output
913 * at the beginning of the line.
914 */
915 if (pending_newline) {
916 rtas_call(display_character, 1, 1, NULL, '\r');
917 rtas_call(display_character, 1, 1, NULL, '\n');
918 pending_newline = 0;
919 } else {
920 current_line = 0;
921 if (form_feed)
922 rtas_call(display_character, 1, 1, NULL,
923 (char)form_feed);
924 else
925 rtas_call(display_character, 1, 1, NULL, '\r');
926 }
927
928 if (row_width)
929 width = row_width[current_line];
930 else
931 width = display_width;
932 os = s;
933 while (*os) {
934 if (*os == '\n' || *os == '\r') {
935 /* If newline is the last character, save it
936 * until next call to avoid bumping up the
937 * display output.
938 */
939 if (*os == '\n' && !os[1]) {
940 pending_newline = 1;
941 current_line++;
942 if (current_line > display_lines-1)
943 current_line = display_lines-1;
944 spin_unlock(&progress_lock);
945 return;
946 }
947
948 /* RTAS wants CR-LF, not just LF */
949
950 if (*os == '\n') {
951 rtas_call(display_character, 1, 1, NULL, '\r');
952 rtas_call(display_character, 1, 1, NULL, '\n');
953 } else {
954 /* CR might be used to re-draw a line, so we'll
955 * leave it alone and not add LF.
956 */
957 rtas_call(display_character, 1, 1, NULL, *os);
958 }
959
960 if (row_width)
961 width = row_width[current_line];
962 else
963 width = display_width;
964 } else {
965 width--;
966 rtas_call(display_character, 1, 1, NULL, *os);
967 }
968
969 os++;
970
971 /* if we overwrite the screen length */
972 if (width <= 0)
973 while ((*os != 0) && (*os != '\n') && (*os != '\r'))
974 os++;
975 }
976
977 spin_unlock(&progress_lock);
978}
979EXPORT_SYMBOL_GPL(rtas_progress); /* needed by rtas_flash module */
980
981int rtas_token(const char *service)
982{
983 const struct rtas_function *func;
984 const __be32 *tokp;
985
986 if (rtas.dev == NULL)
987 return RTAS_UNKNOWN_SERVICE;
988
989 func = rtas_name_to_function(service);
990 if (func)
991 return func->token;
992 /*
993 * The caller is looking up a name that is not known to be an
994 * RTAS function. Either it's a function that needs to be
995 * added to the table, or they're misusing rtas_token() to
996 * access non-function properties of the /rtas node. Warn and
997 * fall back to the legacy behavior.
998 */
999 WARN_ONCE(1, "unknown function `%s`, should it be added to rtas_function_table?\n",
1000 service);
1001
1002 tokp = of_get_property(rtas.dev, service, NULL);
1003 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
1004}
1005EXPORT_SYMBOL_GPL(rtas_token);
1006
1007#ifdef CONFIG_RTAS_ERROR_LOGGING
1008
1009static u32 rtas_error_log_max __ro_after_init = RTAS_ERROR_LOG_MAX;
1010
1011/*
1012 * Return the firmware-specified size of the error log buffer
1013 * for all rtas calls that require an error buffer argument.
1014 * This includes 'check-exception' and 'rtas-last-error'.
1015 */
1016int rtas_get_error_log_max(void)
1017{
1018 return rtas_error_log_max;
1019}
1020
1021static void __init init_error_log_max(void)
1022{
1023 static const char propname[] __initconst = "rtas-error-log-max";
1024 u32 max;
1025
1026 if (of_property_read_u32(rtas.dev, propname, &max)) {
1027 pr_warn("%s not found, using default of %u\n",
1028 propname, RTAS_ERROR_LOG_MAX);
1029 max = RTAS_ERROR_LOG_MAX;
1030 }
1031
1032 if (max > RTAS_ERROR_LOG_MAX) {
1033 pr_warn("%s = %u, clamping max error log size to %u\n",
1034 propname, max, RTAS_ERROR_LOG_MAX);
1035 max = RTAS_ERROR_LOG_MAX;
1036 }
1037
1038 rtas_error_log_max = max;
1039}
1040
1041
1042static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
1043
1044/** Return a copy of the detailed error text associated with the
1045 * most recent failed call to rtas. Because the error text
1046 * might go stale if there are any other intervening rtas calls,
1047 * this routine must be called atomically with whatever produced
1048 * the error (i.e. with rtas_lock still held from the previous call).
1049 */
1050static char *__fetch_rtas_last_error(char *altbuf)
1051{
1052 const s32 token = rtas_function_token(RTAS_FN_RTAS_LAST_ERROR);
1053 struct rtas_args err_args, save_args;
1054 u32 bufsz;
1055 char *buf = NULL;
1056
1057 lockdep_assert_held(&rtas_lock);
1058
1059 if (token == -1)
1060 return NULL;
1061
1062 bufsz = rtas_get_error_log_max();
1063
1064 err_args.token = cpu_to_be32(token);
1065 err_args.nargs = cpu_to_be32(2);
1066 err_args.nret = cpu_to_be32(1);
1067 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
1068 err_args.args[1] = cpu_to_be32(bufsz);
1069 err_args.args[2] = 0;
1070
1071 save_args = rtas_args;
1072 rtas_args = err_args;
1073
1074 do_enter_rtas(&rtas_args);
1075
1076 err_args = rtas_args;
1077 rtas_args = save_args;
1078
1079 /* Log the error in the unlikely case that there was one. */
1080 if (unlikely(err_args.args[2] == 0)) {
1081 if (altbuf) {
1082 buf = altbuf;
1083 } else {
1084 buf = rtas_err_buf;
1085 if (slab_is_available())
1086 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
1087 }
1088 if (buf)
1089 memmove(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
1090 }
1091
1092 return buf;
1093}
1094
1095#define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
1096
1097#else /* CONFIG_RTAS_ERROR_LOGGING */
1098#define __fetch_rtas_last_error(x) NULL
1099#define get_errorlog_buffer() NULL
1100static void __init init_error_log_max(void) {}
1101#endif
1102
1103
1104static void
1105va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
1106 va_list list)
1107{
1108 int i;
1109
1110 args->token = cpu_to_be32(token);
1111 args->nargs = cpu_to_be32(nargs);
1112 args->nret = cpu_to_be32(nret);
1113 args->rets = &(args->args[nargs]);
1114
1115 for (i = 0; i < nargs; ++i)
1116 args->args[i] = cpu_to_be32(va_arg(list, __u32));
1117
1118 for (i = 0; i < nret; ++i)
1119 args->rets[i] = 0;
1120
1121 do_enter_rtas(args);
1122}
1123
1124/**
1125 * rtas_call_unlocked() - Invoke an RTAS firmware function without synchronization.
1126 * @args: RTAS parameter block to be used for the call, must obey RTAS addressing
1127 * constraints.
1128 * @token: Identifies the function being invoked.
1129 * @nargs: Number of input parameters. Does not include token.
1130 * @nret: Number of output parameters, including the call status.
1131 * @....: List of @nargs input parameters.
1132 *
1133 * Invokes the RTAS function indicated by @token, which the caller
1134 * should obtain via rtas_function_token().
1135 *
1136 * This function is similar to rtas_call(), but must be used with a
1137 * limited set of RTAS calls specifically exempted from the general
1138 * requirement that only one RTAS call may be in progress at any
1139 * time. Examples include stop-self and ibm,nmi-interlock.
1140 */
1141void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
1142{
1143 va_list list;
1144
1145 va_start(list, nret);
1146 va_rtas_call_unlocked(args, token, nargs, nret, list);
1147 va_end(list);
1148}
1149
1150static bool token_is_restricted_errinjct(s32 token)
1151{
1152 return token == rtas_function_token(RTAS_FN_IBM_OPEN_ERRINJCT) ||
1153 token == rtas_function_token(RTAS_FN_IBM_ERRINJCT);
1154}
1155
1156/**
1157 * rtas_call() - Invoke an RTAS firmware function.
1158 * @token: Identifies the function being invoked.
1159 * @nargs: Number of input parameters. Does not include token.
1160 * @nret: Number of output parameters, including the call status.
1161 * @outputs: Array of @nret output words.
1162 * @....: List of @nargs input parameters.
1163 *
1164 * Invokes the RTAS function indicated by @token, which the caller
1165 * should obtain via rtas_function_token().
1166 *
1167 * The @nargs and @nret arguments must match the number of input and
1168 * output parameters specified for the RTAS function.
1169 *
1170 * rtas_call() returns RTAS status codes, not conventional Linux errno
1171 * values. Callers must translate any failure to an appropriate errno
1172 * in syscall context. Most callers of RTAS functions that can return
1173 * -2 or 990x should use rtas_busy_delay() to correctly handle those
1174 * statuses before calling again.
1175 *
1176 * The return value descriptions are adapted from 7.2.8 [RTAS] Return
1177 * Codes of the PAPR and CHRP specifications.
1178 *
1179 * Context: Process context preferably, interrupt context if
1180 * necessary. Acquires an internal spinlock and may perform
1181 * GFP_ATOMIC slab allocation in error path. Unsafe for NMI
1182 * context.
1183 * Return:
1184 * * 0 - RTAS function call succeeded.
1185 * * -1 - RTAS function encountered a hardware or
1186 * platform error, or the token is invalid,
1187 * or the function is restricted by kernel policy.
1188 * * -2 - Specs say "A necessary hardware device was busy,
1189 * and the requested function could not be
1190 * performed. The operation should be retried at
1191 * a later time." This is misleading, at least with
1192 * respect to current RTAS implementations. What it
1193 * usually means in practice is that the function
1194 * could not be completed while meeting RTAS's
1195 * deadline for returning control to the OS (250us
1196 * for PAPR/PowerVM, typically), but the call may be
1197 * immediately reattempted to resume work on it.
1198 * * -3 - Parameter error.
1199 * * -7 - Unexpected state change.
1200 * * 9000...9899 - Vendor-specific success codes.
1201 * * 9900...9905 - Advisory extended delay. Caller should try
1202 * again after ~10^x ms has elapsed, where x is
1203 * the last digit of the status [0-5]. Again going
1204 * beyond the PAPR text, 990x on PowerVM indicates
1205 * contention for RTAS-internal resources. Other
1206 * RTAS call sequences in progress should be
1207 * allowed to complete before reattempting the
1208 * call.
1209 * * -9000 - Multi-level isolation error.
1210 * * -9999...-9004 - Vendor-specific error codes.
1211 * * Additional negative values - Function-specific error.
1212 * * Additional positive values - Function-specific success.
1213 */
1214int rtas_call(int token, int nargs, int nret, int *outputs, ...)
1215{
1216 struct pin_cookie cookie;
1217 va_list list;
1218 int i;
1219 unsigned long flags;
1220 struct rtas_args *args;
1221 char *buff_copy = NULL;
1222 int ret;
1223
1224 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
1225 return -1;
1226
1227 if (token_is_restricted_errinjct(token)) {
1228 /*
1229 * It would be nicer to not discard the error value
1230 * from security_locked_down(), but callers expect an
1231 * RTAS status, not an errno.
1232 */
1233 if (security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION))
1234 return -1;
1235 }
1236
1237 if ((mfmsr() & (MSR_IR|MSR_DR)) != (MSR_IR|MSR_DR)) {
1238 WARN_ON_ONCE(1);
1239 return -1;
1240 }
1241
1242 raw_spin_lock_irqsave(&rtas_lock, flags);
1243 cookie = lockdep_pin_lock(&rtas_lock);
1244
1245 /* We use the global rtas args buffer */
1246 args = &rtas_args;
1247
1248 va_start(list, outputs);
1249 va_rtas_call_unlocked(args, token, nargs, nret, list);
1250 va_end(list);
1251
1252 /* A -1 return code indicates that the last command couldn't
1253 be completed due to a hardware error. */
1254 if (be32_to_cpu(args->rets[0]) == -1)
1255 buff_copy = __fetch_rtas_last_error(NULL);
1256
1257 if (nret > 1 && outputs != NULL)
1258 for (i = 0; i < nret-1; ++i)
1259 outputs[i] = be32_to_cpu(args->rets[i + 1]);
1260 ret = (nret > 0) ? be32_to_cpu(args->rets[0]) : 0;
1261
1262 lockdep_unpin_lock(&rtas_lock, cookie);
1263 raw_spin_unlock_irqrestore(&rtas_lock, flags);
1264
1265 if (buff_copy) {
1266 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
1267 if (slab_is_available())
1268 kfree(buff_copy);
1269 }
1270 return ret;
1271}
1272EXPORT_SYMBOL_GPL(rtas_call);
1273
1274/**
1275 * rtas_busy_delay_time() - From an RTAS status value, calculate the
1276 * suggested delay time in milliseconds.
1277 *
1278 * @status: a value returned from rtas_call() or similar APIs which return
1279 * the status of a RTAS function call.
1280 *
1281 * Context: Any context.
1282 *
1283 * Return:
1284 * * 100000 - If @status is 9905.
1285 * * 10000 - If @status is 9904.
1286 * * 1000 - If @status is 9903.
1287 * * 100 - If @status is 9902.
1288 * * 10 - If @status is 9901.
1289 * * 1 - If @status is either 9900 or -2. This is "wrong" for -2, but
1290 * some callers depend on this behavior, and the worst outcome
1291 * is that they will delay for longer than necessary.
1292 * * 0 - If @status is not a busy or extended delay value.
1293 */
1294unsigned int rtas_busy_delay_time(int status)
1295{
1296 int order;
1297 unsigned int ms = 0;
1298
1299 if (status == RTAS_BUSY) {
1300 ms = 1;
1301 } else if (status >= RTAS_EXTENDED_DELAY_MIN &&
1302 status <= RTAS_EXTENDED_DELAY_MAX) {
1303 order = status - RTAS_EXTENDED_DELAY_MIN;
1304 for (ms = 1; order > 0; order--)
1305 ms *= 10;
1306 }
1307
1308 return ms;
1309}
1310
1311/*
1312 * Early boot fallback for rtas_busy_delay().
1313 */
1314static bool __init rtas_busy_delay_early(int status)
1315{
1316 static size_t successive_ext_delays __initdata;
1317 bool retry;
1318
1319 switch (status) {
1320 case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:
1321 /*
1322 * In the unlikely case that we receive an extended
1323 * delay status in early boot, the OS is probably not
1324 * the cause, and there's nothing we can do to clear
1325 * the condition. Best we can do is delay for a bit
1326 * and hope it's transient. Lie to the caller if it
1327 * seems like we're stuck in a retry loop.
1328 */
1329 mdelay(1);
1330 retry = true;
1331 successive_ext_delays += 1;
1332 if (successive_ext_delays > 1000) {
1333 pr_err("too many extended delays, giving up\n");
1334 dump_stack();
1335 retry = false;
1336 successive_ext_delays = 0;
1337 }
1338 break;
1339 case RTAS_BUSY:
1340 retry = true;
1341 successive_ext_delays = 0;
1342 break;
1343 default:
1344 retry = false;
1345 successive_ext_delays = 0;
1346 break;
1347 }
1348
1349 return retry;
1350}
1351
1352/**
1353 * rtas_busy_delay() - helper for RTAS busy and extended delay statuses
1354 *
1355 * @status: a value returned from rtas_call() or similar APIs which return
1356 * the status of a RTAS function call.
1357 *
1358 * Context: Process context. May sleep or schedule.
1359 *
1360 * Return:
1361 * * true - @status is RTAS_BUSY or an extended delay hint. The
1362 * caller may assume that the CPU has been yielded if necessary,
1363 * and that an appropriate delay for @status has elapsed.
1364 * Generally the caller should reattempt the RTAS call which
1365 * yielded @status.
1366 *
1367 * * false - @status is not @RTAS_BUSY nor an extended delay hint. The
1368 * caller is responsible for handling @status.
1369 */
1370bool __ref rtas_busy_delay(int status)
1371{
1372 unsigned int ms;
1373 bool ret;
1374
1375 /*
1376 * Can't do timed sleeps before timekeeping is up.
1377 */
1378 if (system_state < SYSTEM_SCHEDULING)
1379 return rtas_busy_delay_early(status);
1380
1381 switch (status) {
1382 case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX:
1383 ret = true;
1384 ms = rtas_busy_delay_time(status);
1385 /*
1386 * The extended delay hint can be as high as 100 seconds.
1387 * Surely any function returning such a status is either
1388 * buggy or isn't going to be significantly slowed by us
1389 * polling at 1HZ. Clamp the sleep time to one second.
1390 */
1391 ms = clamp(ms, 1U, 1000U);
1392 /*
1393 * The delay hint is an order-of-magnitude suggestion, not a
1394 * minimum. It is fine, possibly even advantageous, for us to
1395 * pause for less time than hinted. To make sure pause time will
1396 * not be way longer than requested independent of HZ
1397 * configuration, use fsleep(). See fsleep() for details of
1398 * used sleeping functions.
1399 */
1400 fsleep(ms * 1000);
1401 break;
1402 case RTAS_BUSY:
1403 ret = true;
1404 /*
1405 * We should call again immediately if there's no other
1406 * work to do.
1407 */
1408 cond_resched();
1409 break;
1410 default:
1411 ret = false;
1412 /*
1413 * Not a busy or extended delay status; the caller should
1414 * handle @status itself. Ensure we warn on misuses in
1415 * atomic context regardless.
1416 */
1417 might_sleep();
1418 break;
1419 }
1420
1421 return ret;
1422}
1423EXPORT_SYMBOL_GPL(rtas_busy_delay);
1424
1425int rtas_error_rc(int rtas_rc)
1426{
1427 int rc;
1428
1429 switch (rtas_rc) {
1430 case RTAS_HARDWARE_ERROR: /* Hardware Error */
1431 rc = -EIO;
1432 break;
1433 case RTAS_INVALID_PARAMETER: /* Bad indicator/domain/etc */
1434 rc = -EINVAL;
1435 break;
1436 case -9000: /* Isolation error */
1437 rc = -EFAULT;
1438 break;
1439 case -9001: /* Outstanding TCE/PTE */
1440 rc = -EEXIST;
1441 break;
1442 case -9002: /* No usable slot */
1443 rc = -ENODEV;
1444 break;
1445 default:
1446 pr_err("%s: unexpected error %d\n", __func__, rtas_rc);
1447 rc = -ERANGE;
1448 break;
1449 }
1450 return rc;
1451}
1452EXPORT_SYMBOL_GPL(rtas_error_rc);
1453
1454int rtas_get_power_level(int powerdomain, int *level)
1455{
1456 int token = rtas_function_token(RTAS_FN_GET_POWER_LEVEL);
1457 int rc;
1458
1459 if (token == RTAS_UNKNOWN_SERVICE)
1460 return -ENOENT;
1461
1462 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
1463 udelay(1);
1464
1465 if (rc < 0)
1466 return rtas_error_rc(rc);
1467 return rc;
1468}
1469EXPORT_SYMBOL_GPL(rtas_get_power_level);
1470
1471int rtas_set_power_level(int powerdomain, int level, int *setlevel)
1472{
1473 int token = rtas_function_token(RTAS_FN_SET_POWER_LEVEL);
1474 int rc;
1475
1476 if (token == RTAS_UNKNOWN_SERVICE)
1477 return -ENOENT;
1478
1479 do {
1480 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
1481 } while (rtas_busy_delay(rc));
1482
1483 if (rc < 0)
1484 return rtas_error_rc(rc);
1485 return rc;
1486}
1487EXPORT_SYMBOL_GPL(rtas_set_power_level);
1488
1489int rtas_get_sensor(int sensor, int index, int *state)
1490{
1491 int token = rtas_function_token(RTAS_FN_GET_SENSOR_STATE);
1492 int rc;
1493
1494 if (token == RTAS_UNKNOWN_SERVICE)
1495 return -ENOENT;
1496
1497 do {
1498 rc = rtas_call(token, 2, 2, state, sensor, index);
1499 } while (rtas_busy_delay(rc));
1500
1501 if (rc < 0)
1502 return rtas_error_rc(rc);
1503 return rc;
1504}
1505EXPORT_SYMBOL_GPL(rtas_get_sensor);
1506
1507int rtas_get_sensor_fast(int sensor, int index, int *state)
1508{
1509 int token = rtas_function_token(RTAS_FN_GET_SENSOR_STATE);
1510 int rc;
1511
1512 if (token == RTAS_UNKNOWN_SERVICE)
1513 return -ENOENT;
1514
1515 rc = rtas_call(token, 2, 2, state, sensor, index);
1516 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
1517 rc <= RTAS_EXTENDED_DELAY_MAX));
1518
1519 if (rc < 0)
1520 return rtas_error_rc(rc);
1521 return rc;
1522}
1523
1524bool rtas_indicator_present(int token, int *maxindex)
1525{
1526 int proplen, count, i;
1527 const struct indicator_elem {
1528 __be32 token;
1529 __be32 maxindex;
1530 } *indicators;
1531
1532 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
1533 if (!indicators)
1534 return false;
1535
1536 count = proplen / sizeof(struct indicator_elem);
1537
1538 for (i = 0; i < count; i++) {
1539 if (__be32_to_cpu(indicators[i].token) != token)
1540 continue;
1541 if (maxindex)
1542 *maxindex = __be32_to_cpu(indicators[i].maxindex);
1543 return true;
1544 }
1545
1546 return false;
1547}
1548
1549int rtas_set_indicator(int indicator, int index, int new_value)
1550{
1551 int token = rtas_function_token(RTAS_FN_SET_INDICATOR);
1552 int rc;
1553
1554 if (token == RTAS_UNKNOWN_SERVICE)
1555 return -ENOENT;
1556
1557 do {
1558 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
1559 } while (rtas_busy_delay(rc));
1560
1561 if (rc < 0)
1562 return rtas_error_rc(rc);
1563 return rc;
1564}
1565EXPORT_SYMBOL_GPL(rtas_set_indicator);
1566
1567/*
1568 * Ignoring RTAS extended delay
1569 */
1570int rtas_set_indicator_fast(int indicator, int index, int new_value)
1571{
1572 int token = rtas_function_token(RTAS_FN_SET_INDICATOR);
1573 int rc;
1574
1575 if (token == RTAS_UNKNOWN_SERVICE)
1576 return -ENOENT;
1577
1578 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
1579
1580 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
1581 rc <= RTAS_EXTENDED_DELAY_MAX));
1582
1583 if (rc < 0)
1584 return rtas_error_rc(rc);
1585
1586 return rc;
1587}
1588
1589/**
1590 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR.
1591 *
1592 * @fw_status: RTAS call status will be placed here if not NULL.
1593 *
1594 * rtas_ibm_suspend_me() should be called only on a CPU which has
1595 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs
1596 * should be waiting to return from H_JOIN.
1597 *
1598 * rtas_ibm_suspend_me() may suspend execution of the OS
1599 * indefinitely. Callers should take appropriate measures upon return, such as
1600 * resetting watchdog facilities.
1601 *
1602 * Callers may choose to retry this call if @fw_status is
1603 * %RTAS_THREADS_ACTIVE.
1604 *
1605 * Return:
1606 * 0 - The partition has resumed from suspend, possibly after
1607 * migration to a different host.
1608 * -ECANCELED - The operation was aborted.
1609 * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call.
1610 * -EBUSY - Some other condition prevented the suspend from succeeding.
1611 * -EIO - Hardware/platform error.
1612 */
1613int rtas_ibm_suspend_me(int *fw_status)
1614{
1615 int token = rtas_function_token(RTAS_FN_IBM_SUSPEND_ME);
1616 int fwrc;
1617 int ret;
1618
1619 fwrc = rtas_call(token, 0, 1, NULL);
1620
1621 switch (fwrc) {
1622 case 0:
1623 ret = 0;
1624 break;
1625 case RTAS_SUSPEND_ABORTED:
1626 ret = -ECANCELED;
1627 break;
1628 case RTAS_THREADS_ACTIVE:
1629 ret = -EAGAIN;
1630 break;
1631 case RTAS_NOT_SUSPENDABLE:
1632 case RTAS_OUTSTANDING_COPROC:
1633 ret = -EBUSY;
1634 break;
1635 case -1:
1636 default:
1637 ret = -EIO;
1638 break;
1639 }
1640
1641 if (fw_status)
1642 *fw_status = fwrc;
1643
1644 return ret;
1645}
1646
1647void __noreturn rtas_restart(char *cmd)
1648{
1649 if (rtas_flash_term_hook)
1650 rtas_flash_term_hook(SYS_RESTART);
1651 pr_emerg("system-reboot returned %d\n",
1652 rtas_call(rtas_function_token(RTAS_FN_SYSTEM_REBOOT), 0, 1, NULL));
1653 for (;;);
1654}
1655
1656void rtas_power_off(void)
1657{
1658 if (rtas_flash_term_hook)
1659 rtas_flash_term_hook(SYS_POWER_OFF);
1660 /* allow power on only with power button press */
1661 pr_emerg("power-off returned %d\n",
1662 rtas_call(rtas_function_token(RTAS_FN_POWER_OFF), 2, 1, NULL, -1, -1));
1663 for (;;);
1664}
1665
1666void __noreturn rtas_halt(void)
1667{
1668 if (rtas_flash_term_hook)
1669 rtas_flash_term_hook(SYS_HALT);
1670 /* allow power on only with power button press */
1671 pr_emerg("power-off returned %d\n",
1672 rtas_call(rtas_function_token(RTAS_FN_POWER_OFF), 2, 1, NULL, -1, -1));
1673 for (;;);
1674}
1675
1676/* Must be in the RMO region, so we place it here */
1677static char rtas_os_term_buf[2048];
1678static bool ibm_extended_os_term;
1679
1680void rtas_os_term(char *str)
1681{
1682 s32 token = rtas_function_token(RTAS_FN_IBM_OS_TERM);
1683 static struct rtas_args args;
1684 int status;
1685
1686 /*
1687 * Firmware with the ibm,extended-os-term property is guaranteed
1688 * to always return from an ibm,os-term call. Earlier versions without
1689 * this property may terminate the partition which we want to avoid
1690 * since it interferes with panic_timeout.
1691 */
1692
1693 if (token == RTAS_UNKNOWN_SERVICE || !ibm_extended_os_term)
1694 return;
1695
1696 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
1697
1698 /*
1699 * Keep calling as long as RTAS returns a "try again" status,
1700 * but don't use rtas_busy_delay(), which potentially
1701 * schedules.
1702 */
1703 do {
1704 rtas_call_unlocked(&args, token, 1, 1, NULL, __pa(rtas_os_term_buf));
1705 status = be32_to_cpu(args.rets[0]);
1706 } while (rtas_busy_delay_time(status));
1707
1708 if (status != 0)
1709 pr_emerg("ibm,os-term call failed %d\n", status);
1710}
1711
1712/**
1713 * rtas_activate_firmware() - Activate a new version of firmware.
1714 *
1715 * Context: This function may sleep.
1716 *
1717 * Activate a new version of partition firmware. The OS must call this
1718 * after resuming from a partition hibernation or migration in order
1719 * to maintain the ability to perform live firmware updates. It's not
1720 * catastrophic for this method to be absent or to fail; just log the
1721 * condition in that case.
1722 */
1723void rtas_activate_firmware(void)
1724{
1725 int token = rtas_function_token(RTAS_FN_IBM_ACTIVATE_FIRMWARE);
1726 int fwrc;
1727
1728 if (token == RTAS_UNKNOWN_SERVICE) {
1729 pr_notice("ibm,activate-firmware method unavailable\n");
1730 return;
1731 }
1732
1733 mutex_lock(&rtas_ibm_activate_firmware_lock);
1734
1735 do {
1736 fwrc = rtas_call(token, 0, 1, NULL);
1737 } while (rtas_busy_delay(fwrc));
1738
1739 mutex_unlock(&rtas_ibm_activate_firmware_lock);
1740
1741 if (fwrc)
1742 pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
1743}
1744
1745/**
1746 * get_pseries_errorlog() - Find a specific pseries error log in an RTAS
1747 * extended event log.
1748 * @log: RTAS error/event log
1749 * @section_id: two character section identifier
1750 *
1751 * Return: A pointer to the specified errorlog or NULL if not found.
1752 */
1753noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
1754 uint16_t section_id)
1755{
1756 struct rtas_ext_event_log_v6 *ext_log =
1757 (struct rtas_ext_event_log_v6 *)log->buffer;
1758 struct pseries_errorlog *sect;
1759 unsigned char *p, *log_end;
1760 uint32_t ext_log_length = rtas_error_extended_log_length(log);
1761 uint8_t log_format = rtas_ext_event_log_format(ext_log);
1762 uint32_t company_id = rtas_ext_event_company_id(ext_log);
1763
1764 /* Check that we understand the format */
1765 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
1766 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
1767 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
1768 return NULL;
1769
1770 log_end = log->buffer + ext_log_length;
1771 p = ext_log->vendor_log;
1772
1773 while (p < log_end) {
1774 sect = (struct pseries_errorlog *)p;
1775 if (pseries_errorlog_id(sect) == section_id)
1776 return sect;
1777 p += pseries_errorlog_length(sect);
1778 }
1779
1780 return NULL;
1781}
1782
1783/*
1784 * The sys_rtas syscall, as originally designed, allows root to pass
1785 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
1786 * can be abused to write to arbitrary memory and do other things that
1787 * are potentially harmful to system integrity, and thus should only
1788 * be used inside the kernel and not exposed to userspace.
1789 *
1790 * All known legitimate users of the sys_rtas syscall will only ever
1791 * pass addresses that fall within the RMO buffer, and use a known
1792 * subset of RTAS calls.
1793 *
1794 * Accordingly, we filter RTAS requests to check that the call is
1795 * permitted, and that provided pointers fall within the RMO buffer.
1796 * If a function is allowed to be invoked via the syscall, then its
1797 * entry in the rtas_functions table points to a rtas_filter that
1798 * describes its constraints, with the indexes of the parameters which
1799 * are expected to contain addresses and sizes of buffers allocated
1800 * inside the RMO buffer.
1801 */
1802
1803static bool in_rmo_buf(u32 base, u32 end)
1804{
1805 return base >= rtas_rmo_buf &&
1806 base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) &&
1807 base <= end &&
1808 end >= rtas_rmo_buf &&
1809 end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE);
1810}
1811
1812static bool block_rtas_call(const struct rtas_function *func, int nargs,
1813 struct rtas_args *args)
1814{
1815 const struct rtas_filter *f;
1816 const bool is_platform_dump =
1817 func == &rtas_function_table[RTAS_FNIDX__IBM_PLATFORM_DUMP];
1818 const bool is_config_conn =
1819 func == &rtas_function_table[RTAS_FNIDX__IBM_CONFIGURE_CONNECTOR];
1820 u32 base, size, end;
1821
1822 /*
1823 * Only functions with filters attached are allowed.
1824 */
1825 f = func->filter;
1826 if (!f)
1827 goto err;
1828 /*
1829 * And some functions aren't allowed on LE.
1830 */
1831 if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) && func->banned_for_syscall_on_le)
1832 goto err;
1833
1834 if (f->buf_idx1 != -1) {
1835 base = be32_to_cpu(args->args[f->buf_idx1]);
1836 if (f->size_idx1 != -1)
1837 size = be32_to_cpu(args->args[f->size_idx1]);
1838 else if (f->fixed_size)
1839 size = f->fixed_size;
1840 else
1841 size = 1;
1842
1843 end = base + size - 1;
1844
1845 /*
1846 * Special case for ibm,platform-dump - NULL buffer
1847 * address is used to indicate end of dump processing
1848 */
1849 if (is_platform_dump && base == 0)
1850 return false;
1851
1852 if (!in_rmo_buf(base, end))
1853 goto err;
1854 }
1855
1856 if (f->buf_idx2 != -1) {
1857 base = be32_to_cpu(args->args[f->buf_idx2]);
1858 if (f->size_idx2 != -1)
1859 size = be32_to_cpu(args->args[f->size_idx2]);
1860 else if (f->fixed_size)
1861 size = f->fixed_size;
1862 else
1863 size = 1;
1864 end = base + size - 1;
1865
1866 /*
1867 * Special case for ibm,configure-connector where the
1868 * address can be 0
1869 */
1870 if (is_config_conn && base == 0)
1871 return false;
1872
1873 if (!in_rmo_buf(base, end))
1874 goto err;
1875 }
1876
1877 return false;
1878err:
1879 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
1880 pr_err_ratelimited("sys_rtas: %s nargs=%d (called by %s)\n",
1881 func->name, nargs, current->comm);
1882 return true;
1883}
1884
1885/* We assume to be passed big endian arguments */
1886SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
1887{
1888 const struct rtas_function *func;
1889 struct pin_cookie cookie;
1890 struct rtas_args args;
1891 unsigned long flags;
1892 char *buff_copy, *errbuf = NULL;
1893 int nargs, nret, token;
1894
1895 if (!capable(CAP_SYS_ADMIN))
1896 return -EPERM;
1897
1898 if (!rtas.entry)
1899 return -EINVAL;
1900
1901 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1902 return -EFAULT;
1903
1904 nargs = be32_to_cpu(args.nargs);
1905 nret = be32_to_cpu(args.nret);
1906 token = be32_to_cpu(args.token);
1907
1908 if (nargs >= ARRAY_SIZE(args.args)
1909 || nret > ARRAY_SIZE(args.args)
1910 || nargs + nret > ARRAY_SIZE(args.args))
1911 return -EINVAL;
1912
1913 nargs = array_index_nospec(nargs, ARRAY_SIZE(args.args));
1914 nret = array_index_nospec(nret, ARRAY_SIZE(args.args) - nargs);
1915
1916 /* Copy in args. */
1917 if (copy_from_user(args.args, uargs->args,
1918 nargs * sizeof(rtas_arg_t)) != 0)
1919 return -EFAULT;
1920
1921 /*
1922 * If this token doesn't correspond to a function the kernel
1923 * understands, you're not allowed to call it.
1924 */
1925 func = rtas_token_to_function_untrusted(token);
1926 if (!func)
1927 return -EINVAL;
1928
1929 args.rets = &args.args[nargs];
1930 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1931
1932 if (block_rtas_call(func, nargs, &args))
1933 return -EINVAL;
1934
1935 if (token_is_restricted_errinjct(token)) {
1936 int err;
1937
1938 err = security_locked_down(LOCKDOWN_RTAS_ERROR_INJECTION);
1939 if (err)
1940 return err;
1941 }
1942
1943 /* Need to handle ibm,suspend_me call specially */
1944 if (token == rtas_function_token(RTAS_FN_IBM_SUSPEND_ME)) {
1945
1946 /*
1947 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1948 * endian, or at least the hcall within it requires it.
1949 */
1950 int rc = 0;
1951 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1952 | be32_to_cpu(args.args[1]);
1953 rc = rtas_syscall_dispatch_ibm_suspend_me(handle);
1954 if (rc == -EAGAIN)
1955 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1956 else if (rc == -EIO)
1957 args.rets[0] = cpu_to_be32(-1);
1958 else if (rc)
1959 return rc;
1960 goto copy_return;
1961 }
1962
1963 buff_copy = get_errorlog_buffer();
1964
1965 /*
1966 * If this function has a mutex assigned to it, we must
1967 * acquire it to avoid interleaving with any kernel-based uses
1968 * of the same function. Kernel-based sequences acquire the
1969 * appropriate mutex explicitly.
1970 */
1971 if (func->lock)
1972 mutex_lock(func->lock);
1973
1974 raw_spin_lock_irqsave(&rtas_lock, flags);
1975 cookie = lockdep_pin_lock(&rtas_lock);
1976
1977 rtas_args = args;
1978 do_enter_rtas(&rtas_args);
1979 args = rtas_args;
1980
1981 /* A -1 return code indicates that the last command couldn't
1982 be completed due to a hardware error. */
1983 if (be32_to_cpu(args.rets[0]) == -1)
1984 errbuf = __fetch_rtas_last_error(buff_copy);
1985
1986 lockdep_unpin_lock(&rtas_lock, cookie);
1987 raw_spin_unlock_irqrestore(&rtas_lock, flags);
1988
1989 if (func->lock)
1990 mutex_unlock(func->lock);
1991
1992 if (buff_copy) {
1993 if (errbuf)
1994 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1995 kfree(buff_copy);
1996 }
1997
1998 copy_return:
1999 /* Copy out args. */
2000 if (copy_to_user(uargs->args + nargs,
2001 args.args + nargs,
2002 nret * sizeof(rtas_arg_t)) != 0)
2003 return -EFAULT;
2004
2005 return 0;
2006}
2007
2008static void __init rtas_function_table_init(void)
2009{
2010 struct property *prop;
2011
2012 for (size_t i = 0; i < ARRAY_SIZE(rtas_function_table); ++i) {
2013 struct rtas_function *curr = &rtas_function_table[i];
2014 struct rtas_function *prior;
2015 int cmp;
2016
2017 curr->token = RTAS_UNKNOWN_SERVICE;
2018
2019 if (i == 0)
2020 continue;
2021 /*
2022 * Ensure table is sorted correctly for binary search
2023 * on function names.
2024 */
2025 prior = &rtas_function_table[i - 1];
2026
2027 cmp = strcmp(prior->name, curr->name);
2028 if (cmp < 0)
2029 continue;
2030
2031 if (cmp == 0) {
2032 pr_err("'%s' has duplicate function table entries\n",
2033 curr->name);
2034 } else {
2035 pr_err("function table unsorted: '%s' wrongly precedes '%s'\n",
2036 prior->name, curr->name);
2037 }
2038 }
2039
2040 for_each_property_of_node(rtas.dev, prop) {
2041 struct rtas_function *func;
2042
2043 if (prop->length != sizeof(u32))
2044 continue;
2045
2046 func = __rtas_name_to_function(prop->name);
2047 if (!func)
2048 continue;
2049
2050 func->token = be32_to_cpup((__be32 *)prop->value);
2051
2052 pr_debug("function %s has token %u\n", func->name, func->token);
2053 }
2054}
2055
2056/*
2057 * Call early during boot, before mem init, to retrieve the RTAS
2058 * information from the device-tree and allocate the RMO buffer for userland
2059 * accesses.
2060 */
2061void __init rtas_initialize(void)
2062{
2063 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
2064 u32 base, size, entry;
2065 int no_base, no_size, no_entry;
2066
2067 /* Get RTAS dev node and fill up our "rtas" structure with infos
2068 * about it.
2069 */
2070 rtas.dev = of_find_node_by_name(NULL, "rtas");
2071 if (!rtas.dev)
2072 return;
2073
2074 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
2075 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
2076 if (no_base || no_size) {
2077 of_node_put(rtas.dev);
2078 rtas.dev = NULL;
2079 return;
2080 }
2081
2082 rtas.base = base;
2083 rtas.size = size;
2084 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
2085 rtas.entry = no_entry ? rtas.base : entry;
2086
2087 init_error_log_max();
2088
2089 /* Must be called before any function token lookups */
2090 rtas_function_table_init();
2091
2092 /*
2093 * Discover this now to avoid a device tree lookup in the
2094 * panic path.
2095 */
2096 ibm_extended_os_term = of_property_read_bool(rtas.dev, "ibm,extended-os-term");
2097
2098 /* If RTAS was found, allocate the RMO buffer for it and look for
2099 * the stop-self token if any
2100 */
2101#ifdef CONFIG_PPC64
2102 if (firmware_has_feature(FW_FEATURE_LPAR))
2103 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
2104#endif
2105 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE,
2106 0, rtas_region);
2107 if (!rtas_rmo_buf)
2108 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
2109 PAGE_SIZE, &rtas_region);
2110
2111 rtas_work_area_reserve_arena(rtas_region);
2112}
2113
2114int __init early_init_dt_scan_rtas(unsigned long node,
2115 const char *uname, int depth, void *data)
2116{
2117 const u32 *basep, *entryp, *sizep;
2118
2119 if (depth != 1 || strcmp(uname, "rtas") != 0)
2120 return 0;
2121
2122 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
2123 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
2124 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
2125
2126#ifdef CONFIG_PPC64
2127 /* need this feature to decide the crashkernel offset */
2128 if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL))
2129 powerpc_firmware_features |= FW_FEATURE_LPAR;
2130#endif
2131
2132 if (basep && entryp && sizep) {
2133 rtas.base = *basep;
2134 rtas.entry = *entryp;
2135 rtas.size = *sizep;
2136 }
2137
2138#ifdef CONFIG_UDBG_RTAS_CONSOLE
2139 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
2140 if (basep)
2141 rtas_putchar_token = *basep;
2142
2143 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
2144 if (basep)
2145 rtas_getchar_token = *basep;
2146
2147 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
2148 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
2149 udbg_init_rtas_console();
2150
2151#endif
2152
2153 /* break now */
2154 return 1;
2155}
2156
2157static DEFINE_RAW_SPINLOCK(timebase_lock);
2158static u64 timebase = 0;
2159
2160void rtas_give_timebase(void)
2161{
2162 unsigned long flags;
2163
2164 raw_spin_lock_irqsave(&timebase_lock, flags);
2165 hard_irq_disable();
2166 rtas_call(rtas_function_token(RTAS_FN_FREEZE_TIME_BASE), 0, 1, NULL);
2167 timebase = get_tb();
2168 raw_spin_unlock(&timebase_lock);
2169
2170 while (timebase)
2171 barrier();
2172 rtas_call(rtas_function_token(RTAS_FN_THAW_TIME_BASE), 0, 1, NULL);
2173 local_irq_restore(flags);
2174}
2175
2176void rtas_take_timebase(void)
2177{
2178 while (!timebase)
2179 barrier();
2180 raw_spin_lock(&timebase_lock);
2181 set_tb(timebase >> 32, timebase & 0xffffffff);
2182 timebase = 0;
2183 raw_spin_unlock(&timebase_lock);
2184}