xref: /openbmc/linux/arch/ia64/kernel/mca_drv.c (revision 5f5bac82)
1 /*
2  * File:	mca_drv.c
3  * Purpose:	Generic MCA handling layer
4  *
5  * Copyright (C) 2004 FUJITSU LIMITED
6  * Copyright (C) 2004 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
7  * Copyright (C) 2005 Silicon Graphics, Inc
8  * Copyright (C) 2005 Keith Owens <kaos@sgi.com>
9  * Copyright (C) 2006 Russ Anderson <rja@sgi.com>
10  */
11 #include <linux/types.h>
12 #include <linux/init.h>
13 #include <linux/sched.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/kallsyms.h>
17 #include <linux/bootmem.h>
18 #include <linux/acpi.h>
19 #include <linux/timer.h>
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/smp.h>
23 #include <linux/workqueue.h>
24 #include <linux/mm.h>
25 
26 #include <asm/delay.h>
27 #include <asm/machvec.h>
28 #include <asm/page.h>
29 #include <asm/ptrace.h>
30 #include <asm/system.h>
31 #include <asm/sal.h>
32 #include <asm/mca.h>
33 
34 #include <asm/irq.h>
35 #include <asm/hw_irq.h>
36 
37 #include "mca_drv.h"
38 
39 /* max size of SAL error record (default) */
40 static int sal_rec_max = 10000;
41 
42 /* from mca_drv_asm.S */
43 extern void *mca_handler_bhhook(void);
44 
45 static DEFINE_SPINLOCK(mca_bh_lock);
46 
47 typedef enum {
48 	MCA_IS_LOCAL  = 0,
49 	MCA_IS_GLOBAL = 1
50 } mca_type_t;
51 
52 #define MAX_PAGE_ISOLATE 1024
53 
54 static struct page *page_isolate[MAX_PAGE_ISOLATE];
55 static int num_page_isolate = 0;
56 
57 typedef enum {
58 	ISOLATE_NG,
59 	ISOLATE_OK,
60 	ISOLATE_NONE
61 } isolate_status_t;
62 
63 typedef enum {
64 	MCA_NOT_RECOVERED = 0,
65 	MCA_RECOVERED	  = 1
66 } recovery_status_t;
67 
68 /*
69  *  This pool keeps pointers to the section part of SAL error record
70  */
71 static struct {
72 	slidx_list_t *buffer; /* section pointer list pool */
73 	int	     cur_idx; /* Current index of section pointer list pool */
74 	int	     max_idx; /* Maximum index of section pointer list pool */
75 } slidx_pool;
76 
77 static int
78 fatal_mca(const char *fmt, ...)
79 {
80 	va_list args;
81 	char buf[256];
82 
83 	va_start(args, fmt);
84 	vsnprintf(buf, sizeof(buf), fmt, args);
85 	va_end(args);
86 	ia64_mca_printk(KERN_ALERT "MCA: %s\n", buf);
87 
88 	return MCA_NOT_RECOVERED;
89 }
90 
91 static int
92 mca_recovered(const char *fmt, ...)
93 {
94 	va_list args;
95 	char buf[256];
96 
97 	va_start(args, fmt);
98 	vsnprintf(buf, sizeof(buf), fmt, args);
99 	va_end(args);
100 	ia64_mca_printk(KERN_INFO "MCA: %s\n", buf);
101 
102 	return MCA_RECOVERED;
103 }
104 
105 /**
106  * mca_page_isolate - isolate a poisoned page in order not to use it later
107  * @paddr:	poisoned memory location
108  *
109  * Return value:
110  *	one of isolate_status_t, ISOLATE_OK/NG/NONE.
111  */
112 
113 static isolate_status_t
114 mca_page_isolate(unsigned long paddr)
115 {
116 	int i;
117 	struct page *p;
118 
119 	/* whether physical address is valid or not */
120 	if (!ia64_phys_addr_valid(paddr))
121 		return ISOLATE_NONE;
122 
123 	if (!pfn_valid(paddr >> PAGE_SHIFT))
124 		return ISOLATE_NONE;
125 
126 	/* convert physical address to physical page number */
127 	p = pfn_to_page(paddr>>PAGE_SHIFT);
128 
129 	/* check whether a page number have been already registered or not */
130 	for (i = 0; i < num_page_isolate; i++)
131 		if (page_isolate[i] == p)
132 			return ISOLATE_OK; /* already listed */
133 
134 	/* limitation check */
135 	if (num_page_isolate == MAX_PAGE_ISOLATE)
136 		return ISOLATE_NG;
137 
138 	/* kick pages having attribute 'SLAB' or 'Reserved' */
139 	if (PageSlab(p) || PageReserved(p))
140 		return ISOLATE_NG;
141 
142 	/* add attribute 'Reserved' and register the page */
143 	get_page(p);
144 	SetPageReserved(p);
145 	page_isolate[num_page_isolate++] = p;
146 
147 	return ISOLATE_OK;
148 }
149 
150 /**
151  * mca_hanlder_bh - Kill the process which occurred memory read error
152  * @paddr:	poisoned address received from MCA Handler
153  */
154 
155 void
156 mca_handler_bh(unsigned long paddr, void *iip, unsigned long ipsr)
157 {
158 	ia64_mlogbuf_dump();
159 	printk(KERN_ERR "OS_MCA: process [cpu %d, pid: %d, uid: %d, "
160 		"iip: %p, psr: 0x%lx,paddr: 0x%lx](%s) encounters MCA.\n",
161 	       raw_smp_processor_id(), current->pid, current_uid(),
162 		iip, ipsr, paddr, current->comm);
163 
164 	spin_lock(&mca_bh_lock);
165 	switch (mca_page_isolate(paddr)) {
166 	case ISOLATE_OK:
167 		printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
168 		break;
169 	case ISOLATE_NG:
170 		printk(KERN_CRIT "Page isolation: ( %lx ) failure.\n", paddr);
171 		break;
172 	default:
173 		break;
174 	}
175 	spin_unlock(&mca_bh_lock);
176 
177 	/* This process is about to be killed itself */
178 	do_exit(SIGKILL);
179 }
180 
181 /**
182  * mca_make_peidx - Make index of processor error section
183  * @slpi:	pointer to record of processor error section
184  * @peidx:	pointer to index of processor error section
185  */
186 
187 static void
188 mca_make_peidx(sal_log_processor_info_t *slpi, peidx_table_t *peidx)
189 {
190 	/*
191 	 * calculate the start address of
192 	 *   "struct cpuid_info" and "sal_processor_static_info_t".
193 	 */
194 	u64 total_check_num = slpi->valid.num_cache_check
195 				+ slpi->valid.num_tlb_check
196 				+ slpi->valid.num_bus_check
197 				+ slpi->valid.num_reg_file_check
198 				+ slpi->valid.num_ms_check;
199 	u64 head_size =	sizeof(sal_log_mod_error_info_t) * total_check_num
200 			+ sizeof(sal_log_processor_info_t);
201 	u64 mid_size  = slpi->valid.cpuid_info * sizeof(struct sal_cpuid_info);
202 
203 	peidx_head(peidx)   = slpi;
204 	peidx_mid(peidx)    = (struct sal_cpuid_info *)
205 		(slpi->valid.cpuid_info ? ((char*)slpi + head_size) : NULL);
206 	peidx_bottom(peidx) = (sal_processor_static_info_t *)
207 		(slpi->valid.psi_static_struct ?
208 			((char*)slpi + head_size + mid_size) : NULL);
209 }
210 
211 /**
212  * mca_make_slidx -  Make index of SAL error record
213  * @buffer:	pointer to SAL error record
214  * @slidx:	pointer to index of SAL error record
215  *
216  * Return value:
217  *	1 if record has platform error / 0 if not
218  */
219 #define LOG_INDEX_ADD_SECT_PTR(sect, ptr) \
220 	{slidx_list_t *hl = &slidx_pool.buffer[slidx_pool.cur_idx]; \
221 	hl->hdr = ptr; \
222 	list_add(&hl->list, &(sect)); \
223 	slidx_pool.cur_idx = (slidx_pool.cur_idx + 1)%slidx_pool.max_idx; }
224 
225 static int
226 mca_make_slidx(void *buffer, slidx_table_t *slidx)
227 {
228 	int platform_err = 0;
229 	int record_len = ((sal_log_record_header_t*)buffer)->len;
230 	u32 ercd_pos;
231 	int sects;
232 	sal_log_section_hdr_t *sp;
233 
234 	/*
235 	 * Initialize index referring current record
236 	 */
237 	INIT_LIST_HEAD(&(slidx->proc_err));
238 	INIT_LIST_HEAD(&(slidx->mem_dev_err));
239 	INIT_LIST_HEAD(&(slidx->sel_dev_err));
240 	INIT_LIST_HEAD(&(slidx->pci_bus_err));
241 	INIT_LIST_HEAD(&(slidx->smbios_dev_err));
242 	INIT_LIST_HEAD(&(slidx->pci_comp_err));
243 	INIT_LIST_HEAD(&(slidx->plat_specific_err));
244 	INIT_LIST_HEAD(&(slidx->host_ctlr_err));
245 	INIT_LIST_HEAD(&(slidx->plat_bus_err));
246 	INIT_LIST_HEAD(&(slidx->unsupported));
247 
248 	/*
249 	 * Extract a Record Header
250 	 */
251 	slidx->header = buffer;
252 
253 	/*
254 	 * Extract each section records
255 	 * (arranged from "int ia64_log_platform_info_print()")
256 	 */
257 	for (ercd_pos = sizeof(sal_log_record_header_t), sects = 0;
258 		ercd_pos < record_len; ercd_pos += sp->len, sects++) {
259 		sp = (sal_log_section_hdr_t *)((char*)buffer + ercd_pos);
260 		if (!efi_guidcmp(sp->guid, SAL_PROC_DEV_ERR_SECT_GUID)) {
261 			LOG_INDEX_ADD_SECT_PTR(slidx->proc_err, sp);
262 		} else if (!efi_guidcmp(sp->guid,
263 				SAL_PLAT_MEM_DEV_ERR_SECT_GUID)) {
264 			platform_err = 1;
265 			LOG_INDEX_ADD_SECT_PTR(slidx->mem_dev_err, sp);
266 		} else if (!efi_guidcmp(sp->guid,
267 				SAL_PLAT_SEL_DEV_ERR_SECT_GUID)) {
268 			platform_err = 1;
269 			LOG_INDEX_ADD_SECT_PTR(slidx->sel_dev_err, sp);
270 		} else if (!efi_guidcmp(sp->guid,
271 				SAL_PLAT_PCI_BUS_ERR_SECT_GUID)) {
272 			platform_err = 1;
273 			LOG_INDEX_ADD_SECT_PTR(slidx->pci_bus_err, sp);
274 		} else if (!efi_guidcmp(sp->guid,
275 				SAL_PLAT_SMBIOS_DEV_ERR_SECT_GUID)) {
276 			platform_err = 1;
277 			LOG_INDEX_ADD_SECT_PTR(slidx->smbios_dev_err, sp);
278 		} else if (!efi_guidcmp(sp->guid,
279 				SAL_PLAT_PCI_COMP_ERR_SECT_GUID)) {
280 			platform_err = 1;
281 			LOG_INDEX_ADD_SECT_PTR(slidx->pci_comp_err, sp);
282 		} else if (!efi_guidcmp(sp->guid,
283 				SAL_PLAT_SPECIFIC_ERR_SECT_GUID)) {
284 			platform_err = 1;
285 			LOG_INDEX_ADD_SECT_PTR(slidx->plat_specific_err, sp);
286 		} else if (!efi_guidcmp(sp->guid,
287 				SAL_PLAT_HOST_CTLR_ERR_SECT_GUID)) {
288 			platform_err = 1;
289 			LOG_INDEX_ADD_SECT_PTR(slidx->host_ctlr_err, sp);
290 		} else if (!efi_guidcmp(sp->guid,
291 				SAL_PLAT_BUS_ERR_SECT_GUID)) {
292 			platform_err = 1;
293 			LOG_INDEX_ADD_SECT_PTR(slidx->plat_bus_err, sp);
294 		} else {
295 			LOG_INDEX_ADD_SECT_PTR(slidx->unsupported, sp);
296 		}
297 	}
298 	slidx->n_sections = sects;
299 
300 	return platform_err;
301 }
302 
303 /**
304  * init_record_index_pools - Initialize pool of lists for SAL record index
305  *
306  * Return value:
307  *	0 on Success / -ENOMEM on Failure
308  */
309 static int
310 init_record_index_pools(void)
311 {
312 	int i;
313 	int rec_max_size;  /* Maximum size of SAL error records */
314 	int sect_min_size; /* Minimum size of SAL error sections */
315 	/* minimum size table of each section */
316 	static int sal_log_sect_min_sizes[] = {
317 		sizeof(sal_log_processor_info_t)
318 		+ sizeof(sal_processor_static_info_t),
319 		sizeof(sal_log_mem_dev_err_info_t),
320 		sizeof(sal_log_sel_dev_err_info_t),
321 		sizeof(sal_log_pci_bus_err_info_t),
322 		sizeof(sal_log_smbios_dev_err_info_t),
323 		sizeof(sal_log_pci_comp_err_info_t),
324 		sizeof(sal_log_plat_specific_err_info_t),
325 		sizeof(sal_log_host_ctlr_err_info_t),
326 		sizeof(sal_log_plat_bus_err_info_t),
327 	};
328 
329 	/*
330 	 * MCA handler cannot allocate new memory on flight,
331 	 * so we preallocate enough memory to handle a SAL record.
332 	 *
333 	 * Initialize a handling set of slidx_pool:
334 	 *   1. Pick up the max size of SAL error records
335 	 *   2. Pick up the min size of SAL error sections
336 	 *   3. Allocate the pool as enough to 2 SAL records
337 	 *     (now we can estimate the maxinum of section in a record.)
338 	 */
339 
340 	/* - 1 - */
341 	rec_max_size = sal_rec_max;
342 
343 	/* - 2 - */
344 	sect_min_size = sal_log_sect_min_sizes[0];
345 	for (i = 1; i < sizeof sal_log_sect_min_sizes/sizeof(size_t); i++)
346 		if (sect_min_size > sal_log_sect_min_sizes[i])
347 			sect_min_size = sal_log_sect_min_sizes[i];
348 
349 	/* - 3 - */
350 	slidx_pool.max_idx = (rec_max_size/sect_min_size) * 2 + 1;
351 	slidx_pool.buffer = (slidx_list_t *)
352 		kmalloc(slidx_pool.max_idx * sizeof(slidx_list_t), GFP_KERNEL);
353 
354 	return slidx_pool.buffer ? 0 : -ENOMEM;
355 }
356 
357 
358 /*****************************************************************************
359  * Recovery functions                                                        *
360  *****************************************************************************/
361 
362 /**
363  * is_mca_global - Check whether this MCA is global or not
364  * @peidx:	pointer of index of processor error section
365  * @pbci:	pointer to pal_bus_check_info_t
366  * @sos:	pointer to hand off struct between SAL and OS
367  *
368  * Return value:
369  *	MCA_IS_LOCAL / MCA_IS_GLOBAL
370  */
371 
372 static mca_type_t
373 is_mca_global(peidx_table_t *peidx, pal_bus_check_info_t *pbci,
374 	      struct ia64_sal_os_state *sos)
375 {
376 	pal_processor_state_info_t *psp =
377 		(pal_processor_state_info_t*)peidx_psp(peidx);
378 
379 	/*
380 	 * PAL can request a rendezvous, if the MCA has a global scope.
381 	 * If "rz_always" flag is set, SAL requests MCA rendezvous
382 	 * in spite of global MCA.
383 	 * Therefore it is local MCA when rendezvous has not been requested.
384 	 * Failed to rendezvous, the system must be down.
385 	 */
386 	switch (sos->rv_rc) {
387 		case -1: /* SAL rendezvous unsuccessful */
388 			return MCA_IS_GLOBAL;
389 		case  0: /* SAL rendezvous not required */
390 			return MCA_IS_LOCAL;
391 		case  1: /* SAL rendezvous successful int */
392 		case  2: /* SAL rendezvous successful int with init */
393 		default:
394 			break;
395 	}
396 
397 	/*
398 	 * If One or more Cache/TLB/Reg_File/Uarch_Check is here,
399 	 * it would be a local MCA. (i.e. processor internal error)
400 	 */
401 	if (psp->tc || psp->cc || psp->rc || psp->uc)
402 		return MCA_IS_LOCAL;
403 
404 	/*
405 	 * Bus_Check structure with Bus_Check.ib (internal bus error) flag set
406 	 * would be a global MCA. (e.g. a system bus address parity error)
407 	 */
408 	if (!pbci || pbci->ib)
409 		return MCA_IS_GLOBAL;
410 
411 	/*
412 	 * Bus_Check structure with Bus_Check.eb (external bus error) flag set
413 	 * could be either a local MCA or a global MCA.
414 	 *
415 	 * Referring Bus_Check.bsi:
416 	 *   0: Unknown/unclassified
417 	 *   1: BERR#
418 	 *   2: BINIT#
419 	 *   3: Hard Fail
420 	 * (FIXME: Are these SGI specific or generic bsi values?)
421 	 */
422 	if (pbci->eb)
423 		switch (pbci->bsi) {
424 			case 0:
425 				/* e.g. a load from poisoned memory */
426 				return MCA_IS_LOCAL;
427 			case 1:
428 			case 2:
429 			case 3:
430 				return MCA_IS_GLOBAL;
431 		}
432 
433 	return MCA_IS_GLOBAL;
434 }
435 
436 /**
437  * get_target_identifier - Get the valid Cache or Bus check target identifier.
438  * @peidx:	pointer of index of processor error section
439  *
440  * Return value:
441  *	target address on Success / 0 on Failure
442  */
443 static u64
444 get_target_identifier(peidx_table_t *peidx)
445 {
446 	u64 target_address = 0;
447 	sal_log_mod_error_info_t *smei;
448 	pal_cache_check_info_t *pcci;
449 	int i, level = 9;
450 
451 	/*
452 	 * Look through the cache checks for a valid target identifier
453 	 * If more than one valid target identifier, return the one
454 	 * with the lowest cache level.
455 	 */
456 	for (i = 0; i < peidx_cache_check_num(peidx); i++) {
457 		smei = (sal_log_mod_error_info_t *)peidx_cache_check(peidx, i);
458 		if (smei->valid.target_identifier && smei->target_identifier) {
459 			pcci = (pal_cache_check_info_t *)&(smei->check_info);
460 			if (!target_address || (pcci->level < level)) {
461 				target_address = smei->target_identifier;
462 				level = pcci->level;
463 				continue;
464 			}
465 		}
466 	}
467 	if (target_address)
468 		return target_address;
469 
470 	/*
471 	 * Look at the bus check for a valid target identifier
472 	 */
473 	smei = peidx_bus_check(peidx, 0);
474 	if (smei && smei->valid.target_identifier)
475 		return smei->target_identifier;
476 
477 	return 0;
478 }
479 
480 /**
481  * recover_from_read_error - Try to recover the errors which type are "read"s.
482  * @slidx:	pointer of index of SAL error record
483  * @peidx:	pointer of index of processor error section
484  * @pbci:	pointer of pal_bus_check_info
485  * @sos:	pointer to hand off struct between SAL and OS
486  *
487  * Return value:
488  *	1 on Success / 0 on Failure
489  */
490 
491 static int
492 recover_from_read_error(slidx_table_t *slidx,
493 			peidx_table_t *peidx, pal_bus_check_info_t *pbci,
494 			struct ia64_sal_os_state *sos)
495 {
496 	u64 target_identifier;
497 	pal_min_state_area_t *pmsa;
498 	struct ia64_psr *psr1, *psr2;
499 	ia64_fptr_t *mca_hdlr_bh = (ia64_fptr_t*)mca_handler_bhhook;
500 
501 	/* Is target address valid? */
502 	target_identifier = get_target_identifier(peidx);
503 	if (!target_identifier)
504 		return fatal_mca("target address not valid");
505 
506 	/*
507 	 * cpu read or memory-mapped io read
508 	 *
509 	 *    offending process  affected process  OS MCA do
510 	 *     kernel mode        kernel mode       down system
511 	 *     kernel mode        user   mode       kill the process
512 	 *     user   mode        kernel mode       down system (*)
513 	 *     user   mode        user   mode       kill the process
514 	 *
515 	 * (*) You could terminate offending user-mode process
516 	 *    if (pbci->pv && pbci->pl != 0) *and* if you sure
517 	 *    the process not have any locks of kernel.
518 	 */
519 
520 	/* Is minstate valid? */
521 	if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
522 		return fatal_mca("minstate not valid");
523 	psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
524 	psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
525 
526 	/*
527 	 *  Check the privilege level of interrupted context.
528 	 *   If it is user-mode, then terminate affected process.
529 	 */
530 
531 	pmsa = sos->pal_min_state;
532 	if (psr1->cpl != 0 ||
533 	   ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
534 		/*
535 		 *  setup for resume to bottom half of MCA,
536 		 * "mca_handler_bhhook"
537 		 */
538 		/* pass to bhhook as argument (gr8, ...) */
539 		pmsa->pmsa_gr[8-1] = target_identifier;
540 		pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
541 		pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
542 		/* set interrupted return address (but no use) */
543 		pmsa->pmsa_br0 = pmsa->pmsa_iip;
544 		/* change resume address to bottom half */
545 		pmsa->pmsa_iip = mca_hdlr_bh->fp;
546 		pmsa->pmsa_gr[1-1] = mca_hdlr_bh->gp;
547 		/* set cpl with kernel mode */
548 		psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
549 		psr2->cpl = 0;
550 		psr2->ri  = 0;
551 		psr2->bn  = 1;
552 		psr2->i  = 0;
553 
554 		return mca_recovered("user memory corruption. "
555 				"kill affected process - recovered.");
556 	}
557 
558 	return fatal_mca("kernel context not recovered, iip 0x%lx\n",
559 			 pmsa->pmsa_iip);
560 }
561 
562 /**
563  * recover_from_platform_error - Recover from platform error.
564  * @slidx:	pointer of index of SAL error record
565  * @peidx:	pointer of index of processor error section
566  * @pbci:	pointer of pal_bus_check_info
567  * @sos:	pointer to hand off struct between SAL and OS
568  *
569  * Return value:
570  *	1 on Success / 0 on Failure
571  */
572 
573 static int
574 recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
575 			    pal_bus_check_info_t *pbci,
576 			    struct ia64_sal_os_state *sos)
577 {
578 	int status = 0;
579 	pal_processor_state_info_t *psp =
580 		(pal_processor_state_info_t*)peidx_psp(peidx);
581 
582 	if (psp->bc && pbci->eb && pbci->bsi == 0) {
583 		switch(pbci->type) {
584 		case 1: /* partial read */
585 		case 3: /* full line(cpu) read */
586 		case 9: /* I/O space read */
587 			status = recover_from_read_error(slidx, peidx, pbci,
588 							 sos);
589 			break;
590 		case 0: /* unknown */
591 		case 2: /* partial write */
592 		case 4: /* full line write */
593 		case 5: /* implicit or explicit write-back operation */
594 		case 6: /* snoop probe */
595 		case 7: /* incoming or outgoing ptc.g */
596 		case 8: /* write coalescing transactions */
597 		case 10: /* I/O space write */
598 		case 11: /* inter-processor interrupt message(IPI) */
599 		case 12: /* interrupt acknowledge or
600 				external task priority cycle */
601 		default:
602 			break;
603 		}
604 	} else if (psp->cc && !psp->bc) {	/* Cache error */
605 		status = recover_from_read_error(slidx, peidx, pbci, sos);
606 	}
607 
608 	return status;
609 }
610 
611 /*
612  * recover_from_tlb_check
613  * @peidx:	pointer of index of processor error section
614  *
615  * Return value:
616  *	1 on Success / 0 on Failure
617  */
618 static int
619 recover_from_tlb_check(peidx_table_t *peidx)
620 {
621 	sal_log_mod_error_info_t *smei;
622 	pal_tlb_check_info_t *ptci;
623 
624 	smei = (sal_log_mod_error_info_t *)peidx_tlb_check(peidx, 0);
625 	ptci = (pal_tlb_check_info_t *)&(smei->check_info);
626 
627 	/*
628 	 * Look for signature of a duplicate TLB DTC entry, which is
629 	 * a SW bug and always fatal.
630 	 */
631 	if (ptci->op == PAL_TLB_CHECK_OP_PURGE
632 	    && !(ptci->itr || ptci->dtc || ptci->itc))
633 		return fatal_mca("Duplicate TLB entry");
634 
635 	return mca_recovered("TLB check recovered");
636 }
637 
638 /**
639  * recover_from_processor_error
640  * @platform:	whether there are some platform error section or not
641  * @slidx:	pointer of index of SAL error record
642  * @peidx:	pointer of index of processor error section
643  * @pbci:	pointer of pal_bus_check_info
644  * @sos:	pointer to hand off struct between SAL and OS
645  *
646  * Return value:
647  *	1 on Success / 0 on Failure
648  */
649 
650 static int
651 recover_from_processor_error(int platform, slidx_table_t *slidx,
652 			     peidx_table_t *peidx, pal_bus_check_info_t *pbci,
653 			     struct ia64_sal_os_state *sos)
654 {
655 	pal_processor_state_info_t *psp =
656 		(pal_processor_state_info_t*)peidx_psp(peidx);
657 
658 	/*
659 	 * Processor recovery status must key off of the PAL recovery
660 	 * status in the Processor State Parameter.
661 	 */
662 
663 	/*
664 	 * The machine check is corrected.
665 	 */
666 	if (psp->cm == 1)
667 		return mca_recovered("machine check is already corrected.");
668 
669 	/*
670 	 * The error was not contained.  Software must be reset.
671 	 */
672 	if (psp->us || psp->ci == 0)
673 		return fatal_mca("error not contained");
674 
675 	/*
676 	 * Look for recoverable TLB check
677 	 */
678 	if (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
679 		return recover_from_tlb_check(peidx);
680 
681 	/*
682 	 * The cache check and bus check bits have four possible states
683 	 *   cc bc
684 	 *    1  1	Memory error, attempt recovery
685 	 *    1  0	Cache error, attempt recovery
686 	 *    0  1	I/O error, attempt recovery
687 	 *    0  0	Other error type, not recovered
688 	 */
689 	if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
690 		return fatal_mca("No cache or bus check");
691 
692 	/*
693 	 * Cannot handle more than one bus check.
694 	 */
695 	if (peidx_bus_check_num(peidx) > 1)
696 		return fatal_mca("Too many bus checks");
697 
698 	if (pbci->ib)
699 		return fatal_mca("Internal Bus error");
700 	if (pbci->eb && pbci->bsi > 0)
701 		return fatal_mca("External bus check fatal status");
702 
703 	/*
704 	 * This is a local MCA and estimated as a recoverable error.
705 	 */
706 	if (platform)
707 		return recover_from_platform_error(slidx, peidx, pbci, sos);
708 
709 	/*
710 	 * On account of strange SAL error record, we cannot recover.
711 	 */
712 	return fatal_mca("Strange SAL record");
713 }
714 
715 /**
716  * mca_try_to_recover - Try to recover from MCA
717  * @rec:	pointer to a SAL error record
718  * @sos:	pointer to hand off struct between SAL and OS
719  *
720  * Return value:
721  *	1 on Success / 0 on Failure
722  */
723 
724 static int
725 mca_try_to_recover(void *rec, struct ia64_sal_os_state *sos)
726 {
727 	int platform_err;
728 	int n_proc_err;
729 	slidx_table_t slidx;
730 	peidx_table_t peidx;
731 	pal_bus_check_info_t pbci;
732 
733 	/* Make index of SAL error record */
734 	platform_err = mca_make_slidx(rec, &slidx);
735 
736 	/* Count processor error sections */
737 	n_proc_err = slidx_count(&slidx, proc_err);
738 
739 	 /* Now, OS can recover when there is one processor error section */
740 	if (n_proc_err > 1)
741 		return fatal_mca("Too Many Errors");
742 	else if (n_proc_err == 0)
743 		/* Weird SAL record ... We can't do anything */
744 		return fatal_mca("Weird SAL record");
745 
746 	/* Make index of processor error section */
747 	mca_make_peidx((sal_log_processor_info_t*)
748 		slidx_first_entry(&slidx.proc_err)->hdr, &peidx);
749 
750 	/* Extract Processor BUS_CHECK[0] */
751 	*((u64*)&pbci) = peidx_check_info(&peidx, bus_check, 0);
752 
753 	/* Check whether MCA is global or not */
754 	if (is_mca_global(&peidx, &pbci, sos))
755 		return fatal_mca("global MCA");
756 
757 	/* Try to recover a processor error */
758 	return recover_from_processor_error(platform_err, &slidx, &peidx,
759 					    &pbci, sos);
760 }
761 
762 /*
763  * =============================================================================
764  */
765 
766 int __init mca_external_handler_init(void)
767 {
768 	if (init_record_index_pools())
769 		return -ENOMEM;
770 
771 	/* register external mca handlers */
772 	if (ia64_reg_MCA_extension(mca_try_to_recover)) {
773 		printk(KERN_ERR "ia64_reg_MCA_extension failed.\n");
774 		kfree(slidx_pool.buffer);
775 		return -EFAULT;
776 	}
777 	return 0;
778 }
779 
780 void __exit mca_external_handler_exit(void)
781 {
782 	/* unregister external mca handlers */
783 	ia64_unreg_MCA_extension();
784 	kfree(slidx_pool.buffer);
785 }
786 
787 module_init(mca_external_handler_init);
788 module_exit(mca_external_handler_exit);
789 
790 module_param(sal_rec_max, int, 0644);
791 MODULE_PARM_DESC(sal_rec_max, "Max size of SAL error record");
792 
793 MODULE_DESCRIPTION("ia64 platform dependent mca handler driver");
794 MODULE_LICENSE("GPL");
795