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Linux/arch/powerpc/kernel/rtas.c

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

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