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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Procedures for interfacing to the RTAS on CHRP machines.
5 *
6 * Peter Bergner, IBM March 2001.
7 * Copyright (C) 2001 IBM.
8 */
9
10#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#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/interrupt.h>
29#include <asm/prom.h>
30#include <asm/rtas.h>
31#include <asm/hvcall.h>
32#include <asm/machdep.h>
33#include <asm/firmware.h>
34#include <asm/page.h>
35#include <asm/param.h>
36#include <asm/delay.h>
37#include <linux/uaccess.h>
38#include <asm/udbg.h>
39#include <asm/syscalls.h>
40#include <asm/smp.h>
41#include <linux/atomic.h>
42#include <asm/time.h>
43#include <asm/mmu.h>
44#include <asm/topology.h>
45#include <asm/paca.h>
46
47/* This is here deliberately so it's only used in this file */
48void enter_rtas(unsigned long);
49
50static inline void do_enter_rtas(unsigned long args)
51{
52 enter_rtas(args);
53
54 srr_regs_clobbered(); /* rtas uses SRRs, invalidate */
55}
56
57struct rtas_t rtas = {
58 .lock = __ARCH_SPIN_LOCK_UNLOCKED
59};
60EXPORT_SYMBOL(rtas);
61
62DEFINE_SPINLOCK(rtas_data_buf_lock);
63EXPORT_SYMBOL(rtas_data_buf_lock);
64
65char rtas_data_buf[RTAS_DATA_BUF_SIZE] __cacheline_aligned;
66EXPORT_SYMBOL(rtas_data_buf);
67
68unsigned long rtas_rmo_buf;
69
70/*
71 * If non-NULL, this gets called when the kernel terminates.
72 * This is done like this so rtas_flash can be a module.
73 */
74void (*rtas_flash_term_hook)(int);
75EXPORT_SYMBOL(rtas_flash_term_hook);
76
77/* RTAS use home made raw locking instead of spin_lock_irqsave
78 * because those can be called from within really nasty contexts
79 * such as having the timebase stopped which would lockup with
80 * normal locks and spinlock debugging enabled
81 */
82static unsigned long lock_rtas(void)
83{
84 unsigned long flags;
85
86 local_irq_save(flags);
87 preempt_disable();
88 arch_spin_lock(&rtas.lock);
89 return flags;
90}
91
92static void unlock_rtas(unsigned long flags)
93{
94 arch_spin_unlock(&rtas.lock);
95 local_irq_restore(flags);
96 preempt_enable();
97}
98
99/*
100 * call_rtas_display_status and call_rtas_display_status_delay
101 * are designed only for very early low-level debugging, which
102 * is why the token is hard-coded to 10.
103 */
104static void call_rtas_display_status(unsigned char c)
105{
106 unsigned long s;
107
108 if (!rtas.base)
109 return;
110
111 s = lock_rtas();
112 rtas_call_unlocked(&rtas.args, 10, 1, 1, NULL, c);
113 unlock_rtas(s);
114}
115
116static void call_rtas_display_status_delay(char c)
117{
118 static int pending_newline = 0; /* did last write end with unprinted newline? */
119 static int width = 16;
120
121 if (c == '\n') {
122 while (width-- > 0)
123 call_rtas_display_status(' ');
124 width = 16;
125 mdelay(500);
126 pending_newline = 1;
127 } else {
128 if (pending_newline) {
129 call_rtas_display_status('\r');
130 call_rtas_display_status('\n');
131 }
132 pending_newline = 0;
133 if (width--) {
134 call_rtas_display_status(c);
135 udelay(10000);
136 }
137 }
138}
139
140void __init udbg_init_rtas_panel(void)
141{
142 udbg_putc = call_rtas_display_status_delay;
143}
144
145#ifdef CONFIG_UDBG_RTAS_CONSOLE
146
147/* If you think you're dying before early_init_dt_scan_rtas() does its
148 * work, you can hard code the token values for your firmware here and
149 * hardcode rtas.base/entry etc.
150 */
151static unsigned int rtas_putchar_token = RTAS_UNKNOWN_SERVICE;
152static unsigned int rtas_getchar_token = RTAS_UNKNOWN_SERVICE;
153
154static void udbg_rtascon_putc(char c)
155{
156 int tries;
157
158 if (!rtas.base)
159 return;
160
161 /* Add CRs before LFs */
162 if (c == '\n')
163 udbg_rtascon_putc('\r');
164
165 /* if there is more than one character to be displayed, wait a bit */
166 for (tries = 0; tries < 16; tries++) {
167 if (rtas_call(rtas_putchar_token, 1, 1, NULL, c) == 0)
168 break;
169 udelay(1000);
170 }
171}
172
173static int udbg_rtascon_getc_poll(void)
174{
175 int c;
176
177 if (!rtas.base)
178 return -1;
179
180 if (rtas_call(rtas_getchar_token, 0, 2, &c))
181 return -1;
182
183 return c;
184}
185
186static int udbg_rtascon_getc(void)
187{
188 int c;
189
190 while ((c = udbg_rtascon_getc_poll()) == -1)
191 ;
192
193 return c;
194}
195
196
197void __init udbg_init_rtas_console(void)
198{
199 udbg_putc = udbg_rtascon_putc;
200 udbg_getc = udbg_rtascon_getc;
201 udbg_getc_poll = udbg_rtascon_getc_poll;
202}
203#endif /* CONFIG_UDBG_RTAS_CONSOLE */
204
205void rtas_progress(char *s, unsigned short hex)
206{
207 struct device_node *root;
208 int width;
209 const __be32 *p;
210 char *os;
211 static int display_character, set_indicator;
212 static int display_width, display_lines, form_feed;
213 static const int *row_width;
214 static DEFINE_SPINLOCK(progress_lock);
215 static int current_line;
216 static int pending_newline = 0; /* did last write end with unprinted newline? */
217
218 if (!rtas.base)
219 return;
220
221 if (display_width == 0) {
222 display_width = 0x10;
223 if ((root = of_find_node_by_path("/rtas"))) {
224 if ((p = of_get_property(root,
225 "ibm,display-line-length", NULL)))
226 display_width = be32_to_cpu(*p);
227 if ((p = of_get_property(root,
228 "ibm,form-feed", NULL)))
229 form_feed = be32_to_cpu(*p);
230 if ((p = of_get_property(root,
231 "ibm,display-number-of-lines", NULL)))
232 display_lines = be32_to_cpu(*p);
233 row_width = of_get_property(root,
234 "ibm,display-truncation-length", NULL);
235 of_node_put(root);
236 }
237 display_character = rtas_token("display-character");
238 set_indicator = rtas_token("set-indicator");
239 }
240
241 if (display_character == RTAS_UNKNOWN_SERVICE) {
242 /* use hex display if available */
243 if (set_indicator != RTAS_UNKNOWN_SERVICE)
244 rtas_call(set_indicator, 3, 1, NULL, 6, 0, hex);
245 return;
246 }
247
248 spin_lock(&progress_lock);
249
250 /*
251 * Last write ended with newline, but we didn't print it since
252 * it would just clear the bottom line of output. Print it now
253 * instead.
254 *
255 * If no newline is pending and form feed is supported, clear the
256 * display with a form feed; otherwise, print a CR to start output
257 * at the beginning of the line.
258 */
259 if (pending_newline) {
260 rtas_call(display_character, 1, 1, NULL, '\r');
261 rtas_call(display_character, 1, 1, NULL, '\n');
262 pending_newline = 0;
263 } else {
264 current_line = 0;
265 if (form_feed)
266 rtas_call(display_character, 1, 1, NULL,
267 (char)form_feed);
268 else
269 rtas_call(display_character, 1, 1, NULL, '\r');
270 }
271
272 if (row_width)
273 width = row_width[current_line];
274 else
275 width = display_width;
276 os = s;
277 while (*os) {
278 if (*os == '\n' || *os == '\r') {
279 /* If newline is the last character, save it
280 * until next call to avoid bumping up the
281 * display output.
282 */
283 if (*os == '\n' && !os[1]) {
284 pending_newline = 1;
285 current_line++;
286 if (current_line > display_lines-1)
287 current_line = display_lines-1;
288 spin_unlock(&progress_lock);
289 return;
290 }
291
292 /* RTAS wants CR-LF, not just LF */
293
294 if (*os == '\n') {
295 rtas_call(display_character, 1, 1, NULL, '\r');
296 rtas_call(display_character, 1, 1, NULL, '\n');
297 } else {
298 /* CR might be used to re-draw a line, so we'll
299 * leave it alone and not add LF.
300 */
301 rtas_call(display_character, 1, 1, NULL, *os);
302 }
303
304 if (row_width)
305 width = row_width[current_line];
306 else
307 width = display_width;
308 } else {
309 width--;
310 rtas_call(display_character, 1, 1, NULL, *os);
311 }
312
313 os++;
314
315 /* if we overwrite the screen length */
316 if (width <= 0)
317 while ((*os != 0) && (*os != '\n') && (*os != '\r'))
318 os++;
319 }
320
321 spin_unlock(&progress_lock);
322}
323EXPORT_SYMBOL(rtas_progress); /* needed by rtas_flash module */
324
325int rtas_token(const char *service)
326{
327 const __be32 *tokp;
328 if (rtas.dev == NULL)
329 return RTAS_UNKNOWN_SERVICE;
330 tokp = of_get_property(rtas.dev, service, NULL);
331 return tokp ? be32_to_cpu(*tokp) : RTAS_UNKNOWN_SERVICE;
332}
333EXPORT_SYMBOL(rtas_token);
334
335int rtas_service_present(const char *service)
336{
337 return rtas_token(service) != RTAS_UNKNOWN_SERVICE;
338}
339EXPORT_SYMBOL(rtas_service_present);
340
341#ifdef CONFIG_RTAS_ERROR_LOGGING
342/*
343 * Return the firmware-specified size of the error log buffer
344 * for all rtas calls that require an error buffer argument.
345 * This includes 'check-exception' and 'rtas-last-error'.
346 */
347int rtas_get_error_log_max(void)
348{
349 static int rtas_error_log_max;
350 if (rtas_error_log_max)
351 return rtas_error_log_max;
352
353 rtas_error_log_max = rtas_token ("rtas-error-log-max");
354 if ((rtas_error_log_max == RTAS_UNKNOWN_SERVICE) ||
355 (rtas_error_log_max > RTAS_ERROR_LOG_MAX)) {
356 printk (KERN_WARNING "RTAS: bad log buffer size %d\n",
357 rtas_error_log_max);
358 rtas_error_log_max = RTAS_ERROR_LOG_MAX;
359 }
360 return rtas_error_log_max;
361}
362EXPORT_SYMBOL(rtas_get_error_log_max);
363
364
365static char rtas_err_buf[RTAS_ERROR_LOG_MAX];
366static int rtas_last_error_token;
367
368/** Return a copy of the detailed error text associated with the
369 * most recent failed call to rtas. Because the error text
370 * might go stale if there are any other intervening rtas calls,
371 * this routine must be called atomically with whatever produced
372 * the error (i.e. with rtas.lock still held from the previous call).
373 */
374static char *__fetch_rtas_last_error(char *altbuf)
375{
376 struct rtas_args err_args, save_args;
377 u32 bufsz;
378 char *buf = NULL;
379
380 if (rtas_last_error_token == -1)
381 return NULL;
382
383 bufsz = rtas_get_error_log_max();
384
385 err_args.token = cpu_to_be32(rtas_last_error_token);
386 err_args.nargs = cpu_to_be32(2);
387 err_args.nret = cpu_to_be32(1);
388 err_args.args[0] = cpu_to_be32(__pa(rtas_err_buf));
389 err_args.args[1] = cpu_to_be32(bufsz);
390 err_args.args[2] = 0;
391
392 save_args = rtas.args;
393 rtas.args = err_args;
394
395 do_enter_rtas(__pa(&rtas.args));
396
397 err_args = rtas.args;
398 rtas.args = save_args;
399
400 /* Log the error in the unlikely case that there was one. */
401 if (unlikely(err_args.args[2] == 0)) {
402 if (altbuf) {
403 buf = altbuf;
404 } else {
405 buf = rtas_err_buf;
406 if (slab_is_available())
407 buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
408 }
409 if (buf)
410 memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
411 }
412
413 return buf;
414}
415
416#define get_errorlog_buffer() kmalloc(RTAS_ERROR_LOG_MAX, GFP_KERNEL)
417
418#else /* CONFIG_RTAS_ERROR_LOGGING */
419#define __fetch_rtas_last_error(x) NULL
420#define get_errorlog_buffer() NULL
421#endif
422
423
424static void
425va_rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret,
426 va_list list)
427{
428 int i;
429
430 args->token = cpu_to_be32(token);
431 args->nargs = cpu_to_be32(nargs);
432 args->nret = cpu_to_be32(nret);
433 args->rets = &(args->args[nargs]);
434
435 for (i = 0; i < nargs; ++i)
436 args->args[i] = cpu_to_be32(va_arg(list, __u32));
437
438 for (i = 0; i < nret; ++i)
439 args->rets[i] = 0;
440
441 do_enter_rtas(__pa(args));
442}
443
444void rtas_call_unlocked(struct rtas_args *args, int token, int nargs, int nret, ...)
445{
446 va_list list;
447
448 va_start(list, nret);
449 va_rtas_call_unlocked(args, token, nargs, nret, list);
450 va_end(list);
451}
452
453int rtas_call(int token, int nargs, int nret, int *outputs, ...)
454{
455 va_list list;
456 int i;
457 unsigned long s;
458 struct rtas_args *rtas_args;
459 char *buff_copy = NULL;
460 int ret;
461
462 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
463 return -1;
464
465 s = lock_rtas();
466
467 /* We use the global rtas args buffer */
468 rtas_args = &rtas.args;
469
470 va_start(list, outputs);
471 va_rtas_call_unlocked(rtas_args, token, nargs, nret, list);
472 va_end(list);
473
474 /* A -1 return code indicates that the last command couldn't
475 be completed due to a hardware error. */
476 if (be32_to_cpu(rtas_args->rets[0]) == -1)
477 buff_copy = __fetch_rtas_last_error(NULL);
478
479 if (nret > 1 && outputs != NULL)
480 for (i = 0; i < nret-1; ++i)
481 outputs[i] = be32_to_cpu(rtas_args->rets[i+1]);
482 ret = (nret > 0)? be32_to_cpu(rtas_args->rets[0]): 0;
483
484 unlock_rtas(s);
485
486 if (buff_copy) {
487 log_error(buff_copy, ERR_TYPE_RTAS_LOG, 0);
488 if (slab_is_available())
489 kfree(buff_copy);
490 }
491 return ret;
492}
493EXPORT_SYMBOL(rtas_call);
494
495/* For RTAS_BUSY (-2), delay for 1 millisecond. For an extended busy status
496 * code of 990n, perform the hinted delay of 10^n (last digit) milliseconds.
497 */
498unsigned int rtas_busy_delay_time(int status)
499{
500 int order;
501 unsigned int ms = 0;
502
503 if (status == RTAS_BUSY) {
504 ms = 1;
505 } else if (status >= RTAS_EXTENDED_DELAY_MIN &&
506 status <= RTAS_EXTENDED_DELAY_MAX) {
507 order = status - RTAS_EXTENDED_DELAY_MIN;
508 for (ms = 1; order > 0; order--)
509 ms *= 10;
510 }
511
512 return ms;
513}
514EXPORT_SYMBOL(rtas_busy_delay_time);
515
516/* For an RTAS busy status code, perform the hinted delay. */
517unsigned int rtas_busy_delay(int status)
518{
519 unsigned int ms;
520
521 might_sleep();
522 ms = rtas_busy_delay_time(status);
523 if (ms && need_resched())
524 msleep(ms);
525
526 return ms;
527}
528EXPORT_SYMBOL(rtas_busy_delay);
529
530static int rtas_error_rc(int rtas_rc)
531{
532 int rc;
533
534 switch (rtas_rc) {
535 case -1: /* Hardware Error */
536 rc = -EIO;
537 break;
538 case -3: /* Bad indicator/domain/etc */
539 rc = -EINVAL;
540 break;
541 case -9000: /* Isolation error */
542 rc = -EFAULT;
543 break;
544 case -9001: /* Outstanding TCE/PTE */
545 rc = -EEXIST;
546 break;
547 case -9002: /* No usable slot */
548 rc = -ENODEV;
549 break;
550 default:
551 printk(KERN_ERR "%s: unexpected RTAS error %d\n",
552 __func__, rtas_rc);
553 rc = -ERANGE;
554 break;
555 }
556 return rc;
557}
558
559int rtas_get_power_level(int powerdomain, int *level)
560{
561 int token = rtas_token("get-power-level");
562 int rc;
563
564 if (token == RTAS_UNKNOWN_SERVICE)
565 return -ENOENT;
566
567 while ((rc = rtas_call(token, 1, 2, level, powerdomain)) == RTAS_BUSY)
568 udelay(1);
569
570 if (rc < 0)
571 return rtas_error_rc(rc);
572 return rc;
573}
574EXPORT_SYMBOL(rtas_get_power_level);
575
576int rtas_set_power_level(int powerdomain, int level, int *setlevel)
577{
578 int token = rtas_token("set-power-level");
579 int rc;
580
581 if (token == RTAS_UNKNOWN_SERVICE)
582 return -ENOENT;
583
584 do {
585 rc = rtas_call(token, 2, 2, setlevel, powerdomain, level);
586 } while (rtas_busy_delay(rc));
587
588 if (rc < 0)
589 return rtas_error_rc(rc);
590 return rc;
591}
592EXPORT_SYMBOL(rtas_set_power_level);
593
594int rtas_get_sensor(int sensor, int index, int *state)
595{
596 int token = rtas_token("get-sensor-state");
597 int rc;
598
599 if (token == RTAS_UNKNOWN_SERVICE)
600 return -ENOENT;
601
602 do {
603 rc = rtas_call(token, 2, 2, state, sensor, index);
604 } while (rtas_busy_delay(rc));
605
606 if (rc < 0)
607 return rtas_error_rc(rc);
608 return rc;
609}
610EXPORT_SYMBOL(rtas_get_sensor);
611
612int rtas_get_sensor_fast(int sensor, int index, int *state)
613{
614 int token = rtas_token("get-sensor-state");
615 int rc;
616
617 if (token == RTAS_UNKNOWN_SERVICE)
618 return -ENOENT;
619
620 rc = rtas_call(token, 2, 2, state, sensor, index);
621 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
622 rc <= RTAS_EXTENDED_DELAY_MAX));
623
624 if (rc < 0)
625 return rtas_error_rc(rc);
626 return rc;
627}
628
629bool rtas_indicator_present(int token, int *maxindex)
630{
631 int proplen, count, i;
632 const struct indicator_elem {
633 __be32 token;
634 __be32 maxindex;
635 } *indicators;
636
637 indicators = of_get_property(rtas.dev, "rtas-indicators", &proplen);
638 if (!indicators)
639 return false;
640
641 count = proplen / sizeof(struct indicator_elem);
642
643 for (i = 0; i < count; i++) {
644 if (__be32_to_cpu(indicators[i].token) != token)
645 continue;
646 if (maxindex)
647 *maxindex = __be32_to_cpu(indicators[i].maxindex);
648 return true;
649 }
650
651 return false;
652}
653EXPORT_SYMBOL(rtas_indicator_present);
654
655int rtas_set_indicator(int indicator, int index, int new_value)
656{
657 int token = rtas_token("set-indicator");
658 int rc;
659
660 if (token == RTAS_UNKNOWN_SERVICE)
661 return -ENOENT;
662
663 do {
664 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
665 } while (rtas_busy_delay(rc));
666
667 if (rc < 0)
668 return rtas_error_rc(rc);
669 return rc;
670}
671EXPORT_SYMBOL(rtas_set_indicator);
672
673/*
674 * Ignoring RTAS extended delay
675 */
676int rtas_set_indicator_fast(int indicator, int index, int new_value)
677{
678 int rc;
679 int token = rtas_token("set-indicator");
680
681 if (token == RTAS_UNKNOWN_SERVICE)
682 return -ENOENT;
683
684 rc = rtas_call(token, 3, 1, NULL, indicator, index, new_value);
685
686 WARN_ON(rc == RTAS_BUSY || (rc >= RTAS_EXTENDED_DELAY_MIN &&
687 rc <= RTAS_EXTENDED_DELAY_MAX));
688
689 if (rc < 0)
690 return rtas_error_rc(rc);
691
692 return rc;
693}
694
695/**
696 * rtas_ibm_suspend_me() - Call ibm,suspend-me to suspend the LPAR.
697 *
698 * @fw_status: RTAS call status will be placed here if not NULL.
699 *
700 * rtas_ibm_suspend_me() should be called only on a CPU which has
701 * received H_CONTINUE from the H_JOIN hcall. All other active CPUs
702 * should be waiting to return from H_JOIN.
703 *
704 * rtas_ibm_suspend_me() may suspend execution of the OS
705 * indefinitely. Callers should take appropriate measures upon return, such as
706 * resetting watchdog facilities.
707 *
708 * Callers may choose to retry this call if @fw_status is
709 * %RTAS_THREADS_ACTIVE.
710 *
711 * Return:
712 * 0 - The partition has resumed from suspend, possibly after
713 * migration to a different host.
714 * -ECANCELED - The operation was aborted.
715 * -EAGAIN - There were other CPUs not in H_JOIN at the time of the call.
716 * -EBUSY - Some other condition prevented the suspend from succeeding.
717 * -EIO - Hardware/platform error.
718 */
719int rtas_ibm_suspend_me(int *fw_status)
720{
721 int fwrc;
722 int ret;
723
724 fwrc = rtas_call(rtas_token("ibm,suspend-me"), 0, 1, NULL);
725
726 switch (fwrc) {
727 case 0:
728 ret = 0;
729 break;
730 case RTAS_SUSPEND_ABORTED:
731 ret = -ECANCELED;
732 break;
733 case RTAS_THREADS_ACTIVE:
734 ret = -EAGAIN;
735 break;
736 case RTAS_NOT_SUSPENDABLE:
737 case RTAS_OUTSTANDING_COPROC:
738 ret = -EBUSY;
739 break;
740 case -1:
741 default:
742 ret = -EIO;
743 break;
744 }
745
746 if (fw_status)
747 *fw_status = fwrc;
748
749 return ret;
750}
751
752void __noreturn rtas_restart(char *cmd)
753{
754 if (rtas_flash_term_hook)
755 rtas_flash_term_hook(SYS_RESTART);
756 printk("RTAS system-reboot returned %d\n",
757 rtas_call(rtas_token("system-reboot"), 0, 1, NULL));
758 for (;;);
759}
760
761void rtas_power_off(void)
762{
763 if (rtas_flash_term_hook)
764 rtas_flash_term_hook(SYS_POWER_OFF);
765 /* allow power on only with power button press */
766 printk("RTAS power-off returned %d\n",
767 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
768 for (;;);
769}
770
771void __noreturn rtas_halt(void)
772{
773 if (rtas_flash_term_hook)
774 rtas_flash_term_hook(SYS_HALT);
775 /* allow power on only with power button press */
776 printk("RTAS power-off returned %d\n",
777 rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1));
778 for (;;);
779}
780
781/* Must be in the RMO region, so we place it here */
782static char rtas_os_term_buf[2048];
783
784void rtas_os_term(char *str)
785{
786 int status;
787
788 /*
789 * Firmware with the ibm,extended-os-term property is guaranteed
790 * to always return from an ibm,os-term call. Earlier versions without
791 * this property may terminate the partition which we want to avoid
792 * since it interferes with panic_timeout.
793 */
794 if (RTAS_UNKNOWN_SERVICE == rtas_token("ibm,os-term") ||
795 RTAS_UNKNOWN_SERVICE == rtas_token("ibm,extended-os-term"))
796 return;
797
798 snprintf(rtas_os_term_buf, 2048, "OS panic: %s", str);
799
800 do {
801 status = rtas_call(rtas_token("ibm,os-term"), 1, 1, NULL,
802 __pa(rtas_os_term_buf));
803 } while (rtas_busy_delay(status));
804
805 if (status != 0)
806 printk(KERN_EMERG "ibm,os-term call failed %d\n", status);
807}
808
809/**
810 * rtas_activate_firmware() - Activate a new version of firmware.
811 *
812 * Activate a new version of partition firmware. The OS must call this
813 * after resuming from a partition hibernation or migration in order
814 * to maintain the ability to perform live firmware updates. It's not
815 * catastrophic for this method to be absent or to fail; just log the
816 * condition in that case.
817 *
818 * Context: This function may sleep.
819 */
820void rtas_activate_firmware(void)
821{
822 int token;
823 int fwrc;
824
825 token = rtas_token("ibm,activate-firmware");
826 if (token == RTAS_UNKNOWN_SERVICE) {
827 pr_notice("ibm,activate-firmware method unavailable\n");
828 return;
829 }
830
831 do {
832 fwrc = rtas_call(token, 0, 1, NULL);
833 } while (rtas_busy_delay(fwrc));
834
835 if (fwrc)
836 pr_err("ibm,activate-firmware failed (%i)\n", fwrc);
837}
838
839#ifdef CONFIG_PPC_PSERIES
840/**
841 * rtas_call_reentrant() - Used for reentrant rtas calls
842 * @token: Token for desired reentrant RTAS call
843 * @nargs: Number of Input Parameters
844 * @nret: Number of Output Parameters
845 * @outputs: Array of outputs
846 * @...: Inputs for desired RTAS call
847 *
848 * According to LoPAR documentation, only "ibm,int-on", "ibm,int-off",
849 * "ibm,get-xive" and "ibm,set-xive" are currently reentrant.
850 * Reentrant calls need their own rtas_args buffer, so not using rtas.args, but
851 * PACA one instead.
852 *
853 * Return: -1 on error,
854 * First output value of RTAS call if (nret > 0),
855 * 0 otherwise,
856 */
857int rtas_call_reentrant(int token, int nargs, int nret, int *outputs, ...)
858{
859 va_list list;
860 struct rtas_args *args;
861 unsigned long flags;
862 int i, ret = 0;
863
864 if (!rtas.entry || token == RTAS_UNKNOWN_SERVICE)
865 return -1;
866
867 local_irq_save(flags);
868 preempt_disable();
869
870 /* We use the per-cpu (PACA) rtas args buffer */
871 args = local_paca->rtas_args_reentrant;
872
873 va_start(list, outputs);
874 va_rtas_call_unlocked(args, token, nargs, nret, list);
875 va_end(list);
876
877 if (nret > 1 && outputs)
878 for (i = 0; i < nret - 1; ++i)
879 outputs[i] = be32_to_cpu(args->rets[i + 1]);
880
881 if (nret > 0)
882 ret = be32_to_cpu(args->rets[0]);
883
884 local_irq_restore(flags);
885 preempt_enable();
886
887 return ret;
888}
889
890#endif /* CONFIG_PPC_PSERIES */
891
892/**
893 * Find a specific pseries error log in an RTAS extended event log.
894 * @log: RTAS error/event log
895 * @section_id: two character section identifier
896 *
897 * Returns a pointer to the specified errorlog or NULL if not found.
898 */
899struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log,
900 uint16_t section_id)
901{
902 struct rtas_ext_event_log_v6 *ext_log =
903 (struct rtas_ext_event_log_v6 *)log->buffer;
904 struct pseries_errorlog *sect;
905 unsigned char *p, *log_end;
906 uint32_t ext_log_length = rtas_error_extended_log_length(log);
907 uint8_t log_format = rtas_ext_event_log_format(ext_log);
908 uint32_t company_id = rtas_ext_event_company_id(ext_log);
909
910 /* Check that we understand the format */
911 if (ext_log_length < sizeof(struct rtas_ext_event_log_v6) ||
912 log_format != RTAS_V6EXT_LOG_FORMAT_EVENT_LOG ||
913 company_id != RTAS_V6EXT_COMPANY_ID_IBM)
914 return NULL;
915
916 log_end = log->buffer + ext_log_length;
917 p = ext_log->vendor_log;
918
919 while (p < log_end) {
920 sect = (struct pseries_errorlog *)p;
921 if (pseries_errorlog_id(sect) == section_id)
922 return sect;
923 p += pseries_errorlog_length(sect);
924 }
925
926 return NULL;
927}
928
929#ifdef CONFIG_PPC_RTAS_FILTER
930
931/*
932 * The sys_rtas syscall, as originally designed, allows root to pass
933 * arbitrary physical addresses to RTAS calls. A number of RTAS calls
934 * can be abused to write to arbitrary memory and do other things that
935 * are potentially harmful to system integrity, and thus should only
936 * be used inside the kernel and not exposed to userspace.
937 *
938 * All known legitimate users of the sys_rtas syscall will only ever
939 * pass addresses that fall within the RMO buffer, and use a known
940 * subset of RTAS calls.
941 *
942 * Accordingly, we filter RTAS requests to check that the call is
943 * permitted, and that provided pointers fall within the RMO buffer.
944 * The rtas_filters list contains an entry for each permitted call,
945 * with the indexes of the parameters which are expected to contain
946 * addresses and sizes of buffers allocated inside the RMO buffer.
947 */
948struct rtas_filter {
949 const char *name;
950 int token;
951 /* Indexes into the args buffer, -1 if not used */
952 int buf_idx1;
953 int size_idx1;
954 int buf_idx2;
955 int size_idx2;
956
957 int fixed_size;
958};
959
960static struct rtas_filter rtas_filters[] __ro_after_init = {
961 { "ibm,activate-firmware", -1, -1, -1, -1, -1 },
962 { "ibm,configure-connector", -1, 0, -1, 1, -1, 4096 }, /* Special cased */
963 { "display-character", -1, -1, -1, -1, -1 },
964 { "ibm,display-message", -1, 0, -1, -1, -1 },
965 { "ibm,errinjct", -1, 2, -1, -1, -1, 1024 },
966 { "ibm,close-errinjct", -1, -1, -1, -1, -1 },
967 { "ibm,open-errinjct", -1, -1, -1, -1, -1 },
968 { "ibm,get-config-addr-info2", -1, -1, -1, -1, -1 },
969 { "ibm,get-dynamic-sensor-state", -1, 1, -1, -1, -1 },
970 { "ibm,get-indices", -1, 2, 3, -1, -1 },
971 { "get-power-level", -1, -1, -1, -1, -1 },
972 { "get-sensor-state", -1, -1, -1, -1, -1 },
973 { "ibm,get-system-parameter", -1, 1, 2, -1, -1 },
974 { "get-time-of-day", -1, -1, -1, -1, -1 },
975 { "ibm,get-vpd", -1, 0, -1, 1, 2 },
976 { "ibm,lpar-perftools", -1, 2, 3, -1, -1 },
977 { "ibm,platform-dump", -1, 4, 5, -1, -1 },
978 { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 },
979 { "ibm,scan-log-dump", -1, 0, 1, -1, -1 },
980 { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 },
981 { "ibm,set-eeh-option", -1, -1, -1, -1, -1 },
982 { "set-indicator", -1, -1, -1, -1, -1 },
983 { "set-power-level", -1, -1, -1, -1, -1 },
984 { "set-time-for-power-on", -1, -1, -1, -1, -1 },
985 { "ibm,set-system-parameter", -1, 1, -1, -1, -1 },
986 { "set-time-of-day", -1, -1, -1, -1, -1 },
987#ifdef CONFIG_CPU_BIG_ENDIAN
988 { "ibm,suspend-me", -1, -1, -1, -1, -1 },
989 { "ibm,update-nodes", -1, 0, -1, -1, -1, 4096 },
990 { "ibm,update-properties", -1, 0, -1, -1, -1, 4096 },
991#endif
992 { "ibm,physical-attestation", -1, 0, 1, -1, -1 },
993};
994
995static bool in_rmo_buf(u32 base, u32 end)
996{
997 return base >= rtas_rmo_buf &&
998 base < (rtas_rmo_buf + RTAS_USER_REGION_SIZE) &&
999 base <= end &&
1000 end >= rtas_rmo_buf &&
1001 end < (rtas_rmo_buf + RTAS_USER_REGION_SIZE);
1002}
1003
1004static bool block_rtas_call(int token, int nargs,
1005 struct rtas_args *args)
1006{
1007 int i;
1008
1009 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++) {
1010 struct rtas_filter *f = &rtas_filters[i];
1011 u32 base, size, end;
1012
1013 if (token != f->token)
1014 continue;
1015
1016 if (f->buf_idx1 != -1) {
1017 base = be32_to_cpu(args->args[f->buf_idx1]);
1018 if (f->size_idx1 != -1)
1019 size = be32_to_cpu(args->args[f->size_idx1]);
1020 else if (f->fixed_size)
1021 size = f->fixed_size;
1022 else
1023 size = 1;
1024
1025 end = base + size - 1;
1026 if (!in_rmo_buf(base, end))
1027 goto err;
1028 }
1029
1030 if (f->buf_idx2 != -1) {
1031 base = be32_to_cpu(args->args[f->buf_idx2]);
1032 if (f->size_idx2 != -1)
1033 size = be32_to_cpu(args->args[f->size_idx2]);
1034 else if (f->fixed_size)
1035 size = f->fixed_size;
1036 else
1037 size = 1;
1038 end = base + size - 1;
1039
1040 /*
1041 * Special case for ibm,configure-connector where the
1042 * address can be 0
1043 */
1044 if (!strcmp(f->name, "ibm,configure-connector") &&
1045 base == 0)
1046 return false;
1047
1048 if (!in_rmo_buf(base, end))
1049 goto err;
1050 }
1051
1052 return false;
1053 }
1054
1055err:
1056 pr_err_ratelimited("sys_rtas: RTAS call blocked - exploit attempt?\n");
1057 pr_err_ratelimited("sys_rtas: token=0x%x, nargs=%d (called by %s)\n",
1058 token, nargs, current->comm);
1059 return true;
1060}
1061
1062static void __init rtas_syscall_filter_init(void)
1063{
1064 unsigned int i;
1065
1066 for (i = 0; i < ARRAY_SIZE(rtas_filters); i++)
1067 rtas_filters[i].token = rtas_token(rtas_filters[i].name);
1068}
1069
1070#else
1071
1072static bool block_rtas_call(int token, int nargs,
1073 struct rtas_args *args)
1074{
1075 return false;
1076}
1077
1078static void __init rtas_syscall_filter_init(void)
1079{
1080}
1081
1082#endif /* CONFIG_PPC_RTAS_FILTER */
1083
1084/* We assume to be passed big endian arguments */
1085SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)
1086{
1087 struct rtas_args args;
1088 unsigned long flags;
1089 char *buff_copy, *errbuf = NULL;
1090 int nargs, nret, token;
1091
1092 if (!capable(CAP_SYS_ADMIN))
1093 return -EPERM;
1094
1095 if (!rtas.entry)
1096 return -EINVAL;
1097
1098 if (copy_from_user(&args, uargs, 3 * sizeof(u32)) != 0)
1099 return -EFAULT;
1100
1101 nargs = be32_to_cpu(args.nargs);
1102 nret = be32_to_cpu(args.nret);
1103 token = be32_to_cpu(args.token);
1104
1105 if (nargs >= ARRAY_SIZE(args.args)
1106 || nret > ARRAY_SIZE(args.args)
1107 || nargs + nret > ARRAY_SIZE(args.args))
1108 return -EINVAL;
1109
1110 /* Copy in args. */
1111 if (copy_from_user(args.args, uargs->args,
1112 nargs * sizeof(rtas_arg_t)) != 0)
1113 return -EFAULT;
1114
1115 if (token == RTAS_UNKNOWN_SERVICE)
1116 return -EINVAL;
1117
1118 args.rets = &args.args[nargs];
1119 memset(args.rets, 0, nret * sizeof(rtas_arg_t));
1120
1121 if (block_rtas_call(token, nargs, &args))
1122 return -EINVAL;
1123
1124 /* Need to handle ibm,suspend_me call specially */
1125 if (token == rtas_token("ibm,suspend-me")) {
1126
1127 /*
1128 * rtas_ibm_suspend_me assumes the streamid handle is in cpu
1129 * endian, or at least the hcall within it requires it.
1130 */
1131 int rc = 0;
1132 u64 handle = ((u64)be32_to_cpu(args.args[0]) << 32)
1133 | be32_to_cpu(args.args[1]);
1134 rc = rtas_syscall_dispatch_ibm_suspend_me(handle);
1135 if (rc == -EAGAIN)
1136 args.rets[0] = cpu_to_be32(RTAS_NOT_SUSPENDABLE);
1137 else if (rc == -EIO)
1138 args.rets[0] = cpu_to_be32(-1);
1139 else if (rc)
1140 return rc;
1141 goto copy_return;
1142 }
1143
1144 buff_copy = get_errorlog_buffer();
1145
1146 flags = lock_rtas();
1147
1148 rtas.args = args;
1149 do_enter_rtas(__pa(&rtas.args));
1150 args = rtas.args;
1151
1152 /* A -1 return code indicates that the last command couldn't
1153 be completed due to a hardware error. */
1154 if (be32_to_cpu(args.rets[0]) == -1)
1155 errbuf = __fetch_rtas_last_error(buff_copy);
1156
1157 unlock_rtas(flags);
1158
1159 if (buff_copy) {
1160 if (errbuf)
1161 log_error(errbuf, ERR_TYPE_RTAS_LOG, 0);
1162 kfree(buff_copy);
1163 }
1164
1165 copy_return:
1166 /* Copy out args. */
1167 if (copy_to_user(uargs->args + nargs,
1168 args.args + nargs,
1169 nret * sizeof(rtas_arg_t)) != 0)
1170 return -EFAULT;
1171
1172 return 0;
1173}
1174
1175/*
1176 * Call early during boot, before mem init, to retrieve the RTAS
1177 * information from the device-tree and allocate the RMO buffer for userland
1178 * accesses.
1179 */
1180void __init rtas_initialize(void)
1181{
1182 unsigned long rtas_region = RTAS_INSTANTIATE_MAX;
1183 u32 base, size, entry;
1184 int no_base, no_size, no_entry;
1185
1186 /* Get RTAS dev node and fill up our "rtas" structure with infos
1187 * about it.
1188 */
1189 rtas.dev = of_find_node_by_name(NULL, "rtas");
1190 if (!rtas.dev)
1191 return;
1192
1193 no_base = of_property_read_u32(rtas.dev, "linux,rtas-base", &base);
1194 no_size = of_property_read_u32(rtas.dev, "rtas-size", &size);
1195 if (no_base || no_size) {
1196 of_node_put(rtas.dev);
1197 rtas.dev = NULL;
1198 return;
1199 }
1200
1201 rtas.base = base;
1202 rtas.size = size;
1203 no_entry = of_property_read_u32(rtas.dev, "linux,rtas-entry", &entry);
1204 rtas.entry = no_entry ? rtas.base : entry;
1205
1206 /* If RTAS was found, allocate the RMO buffer for it and look for
1207 * the stop-self token if any
1208 */
1209#ifdef CONFIG_PPC64
1210 if (firmware_has_feature(FW_FEATURE_LPAR))
1211 rtas_region = min(ppc64_rma_size, RTAS_INSTANTIATE_MAX);
1212#endif
1213 rtas_rmo_buf = memblock_phys_alloc_range(RTAS_USER_REGION_SIZE, PAGE_SIZE,
1214 0, rtas_region);
1215 if (!rtas_rmo_buf)
1216 panic("ERROR: RTAS: Failed to allocate %lx bytes below %pa\n",
1217 PAGE_SIZE, &rtas_region);
1218
1219#ifdef CONFIG_RTAS_ERROR_LOGGING
1220 rtas_last_error_token = rtas_token("rtas-last-error");
1221#endif
1222
1223 rtas_syscall_filter_init();
1224}
1225
1226int __init early_init_dt_scan_rtas(unsigned long node,
1227 const char *uname, int depth, void *data)
1228{
1229 const u32 *basep, *entryp, *sizep;
1230
1231 if (depth != 1 || strcmp(uname, "rtas") != 0)
1232 return 0;
1233
1234 basep = of_get_flat_dt_prop(node, "linux,rtas-base", NULL);
1235 entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
1236 sizep = of_get_flat_dt_prop(node, "rtas-size", NULL);
1237
1238 if (basep && entryp && sizep) {
1239 rtas.base = *basep;
1240 rtas.entry = *entryp;
1241 rtas.size = *sizep;
1242 }
1243
1244#ifdef CONFIG_UDBG_RTAS_CONSOLE
1245 basep = of_get_flat_dt_prop(node, "put-term-char", NULL);
1246 if (basep)
1247 rtas_putchar_token = *basep;
1248
1249 basep = of_get_flat_dt_prop(node, "get-term-char", NULL);
1250 if (basep)
1251 rtas_getchar_token = *basep;
1252
1253 if (rtas_putchar_token != RTAS_UNKNOWN_SERVICE &&
1254 rtas_getchar_token != RTAS_UNKNOWN_SERVICE)
1255 udbg_init_rtas_console();
1256
1257#endif
1258
1259 /* break now */
1260 return 1;
1261}
1262
1263static arch_spinlock_t timebase_lock;
1264static u64 timebase = 0;
1265
1266void rtas_give_timebase(void)
1267{
1268 unsigned long flags;
1269
1270 local_irq_save(flags);
1271 hard_irq_disable();
1272 arch_spin_lock(&timebase_lock);
1273 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
1274 timebase = get_tb();
1275 arch_spin_unlock(&timebase_lock);
1276
1277 while (timebase)
1278 barrier();
1279 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
1280 local_irq_restore(flags);
1281}
1282
1283void rtas_take_timebase(void)
1284{
1285 while (!timebase)
1286 barrier();
1287 arch_spin_lock(&timebase_lock);
1288 set_tb(timebase >> 32, timebase & 0xffffffff);
1289 timebase = 0;
1290 arch_spin_unlock(&timebase_lock);
1291}