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#include <linux/slab.h>
26
27#include <asm/delay.h>
28#include <asm/machvec.h>
29#include <asm/page.h>
30#include <asm/ptrace.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) */
40static int sal_rec_max = 10000;
41
42/* from mca_drv_asm.S */
43extern void *mca_handler_bhhook(void);
44
45static DEFINE_SPINLOCK(mca_bh_lock);
46
47typedef enum {
48	MCA_IS_LOCAL  = 0,
49	MCA_IS_GLOBAL = 1
50} mca_type_t;
51
52#define MAX_PAGE_ISOLATE 1024
53
54static struct page *page_isolate[MAX_PAGE_ISOLATE];
55static int num_page_isolate = 0;
56
57typedef enum {
58	ISOLATE_NG,
59	ISOLATE_OK,
60	ISOLATE_NONE
61} isolate_status_t;
62
63typedef 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 */
71static 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
77static int
78fatal_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
91static int
92mca_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
113static isolate_status_t
114mca_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
155void
156mca_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,
162		from_kuid(&init_user_ns, current_uid()),
163		iip, ipsr, paddr, current->comm);
164
165	spin_lock(&mca_bh_lock);
166	switch (mca_page_isolate(paddr)) {
167	case ISOLATE_OK:
168		printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
169		break;
170	case ISOLATE_NG:
171		printk(KERN_CRIT "Page isolation: ( %lx ) failure.\n", paddr);
172		break;
173	default:
174		break;
175	}
176	spin_unlock(&mca_bh_lock);
177
178	/* This process is about to be killed itself */
179	do_exit(SIGKILL);
180}
181
182/**
183 * mca_make_peidx - Make index of processor error section
184 * @slpi:	pointer to record of processor error section
185 * @peidx:	pointer to index of processor error section
186 */
187
188static void
189mca_make_peidx(sal_log_processor_info_t *slpi, peidx_table_t *peidx)
190{
191	/*
192	 * calculate the start address of
193	 *   "struct cpuid_info" and "sal_processor_static_info_t".
194	 */
195	u64 total_check_num = slpi->valid.num_cache_check
196				+ slpi->valid.num_tlb_check
197				+ slpi->valid.num_bus_check
198				+ slpi->valid.num_reg_file_check
199				+ slpi->valid.num_ms_check;
200	u64 head_size =	sizeof(sal_log_mod_error_info_t) * total_check_num
201			+ sizeof(sal_log_processor_info_t);
202	u64 mid_size  = slpi->valid.cpuid_info * sizeof(struct sal_cpuid_info);
203
204	peidx_head(peidx)   = slpi;
205	peidx_mid(peidx)    = (struct sal_cpuid_info *)
206		(slpi->valid.cpuid_info ? ((char*)slpi + head_size) : NULL);
207	peidx_bottom(peidx) = (sal_processor_static_info_t *)
208		(slpi->valid.psi_static_struct ?
209			((char*)slpi + head_size + mid_size) : NULL);
210}
211
212/**
213 * mca_make_slidx -  Make index of SAL error record
214 * @buffer:	pointer to SAL error record
215 * @slidx:	pointer to index of SAL error record
216 *
217 * Return value:
218 *	1 if record has platform error / 0 if not
219 */
220#define LOG_INDEX_ADD_SECT_PTR(sect, ptr) \
221	{slidx_list_t *hl = &slidx_pool.buffer[slidx_pool.cur_idx]; \
222	hl->hdr = ptr; \
223	list_add(&hl->list, &(sect)); \
224	slidx_pool.cur_idx = (slidx_pool.cur_idx + 1)%slidx_pool.max_idx; }
225
226static int
227mca_make_slidx(void *buffer, slidx_table_t *slidx)
228{
229	int platform_err = 0;
230	int record_len = ((sal_log_record_header_t*)buffer)->len;
231	u32 ercd_pos;
232	int sects;
233	sal_log_section_hdr_t *sp;
234
235	/*
236	 * Initialize index referring current record
237	 */
238	INIT_LIST_HEAD(&(slidx->proc_err));
239	INIT_LIST_HEAD(&(slidx->mem_dev_err));
240	INIT_LIST_HEAD(&(slidx->sel_dev_err));
241	INIT_LIST_HEAD(&(slidx->pci_bus_err));
242	INIT_LIST_HEAD(&(slidx->smbios_dev_err));
243	INIT_LIST_HEAD(&(slidx->pci_comp_err));
244	INIT_LIST_HEAD(&(slidx->plat_specific_err));
245	INIT_LIST_HEAD(&(slidx->host_ctlr_err));
246	INIT_LIST_HEAD(&(slidx->plat_bus_err));
247	INIT_LIST_HEAD(&(slidx->unsupported));
248
249	/*
250	 * Extract a Record Header
251	 */
252	slidx->header = buffer;
253
254	/*
255	 * Extract each section records
256	 * (arranged from "int ia64_log_platform_info_print()")
257	 */
258	for (ercd_pos = sizeof(sal_log_record_header_t), sects = 0;
259		ercd_pos < record_len; ercd_pos += sp->len, sects++) {
260		sp = (sal_log_section_hdr_t *)((char*)buffer + ercd_pos);
261		if (!efi_guidcmp(sp->guid, SAL_PROC_DEV_ERR_SECT_GUID)) {
262			LOG_INDEX_ADD_SECT_PTR(slidx->proc_err, sp);
263		} else if (!efi_guidcmp(sp->guid,
264				SAL_PLAT_MEM_DEV_ERR_SECT_GUID)) {
265			platform_err = 1;
266			LOG_INDEX_ADD_SECT_PTR(slidx->mem_dev_err, sp);
267		} else if (!efi_guidcmp(sp->guid,
268				SAL_PLAT_SEL_DEV_ERR_SECT_GUID)) {
269			platform_err = 1;
270			LOG_INDEX_ADD_SECT_PTR(slidx->sel_dev_err, sp);
271		} else if (!efi_guidcmp(sp->guid,
272				SAL_PLAT_PCI_BUS_ERR_SECT_GUID)) {
273			platform_err = 1;
274			LOG_INDEX_ADD_SECT_PTR(slidx->pci_bus_err, sp);
275		} else if (!efi_guidcmp(sp->guid,
276				SAL_PLAT_SMBIOS_DEV_ERR_SECT_GUID)) {
277			platform_err = 1;
278			LOG_INDEX_ADD_SECT_PTR(slidx->smbios_dev_err, sp);
279		} else if (!efi_guidcmp(sp->guid,
280				SAL_PLAT_PCI_COMP_ERR_SECT_GUID)) {
281			platform_err = 1;
282			LOG_INDEX_ADD_SECT_PTR(slidx->pci_comp_err, sp);
283		} else if (!efi_guidcmp(sp->guid,
284				SAL_PLAT_SPECIFIC_ERR_SECT_GUID)) {
285			platform_err = 1;
286			LOG_INDEX_ADD_SECT_PTR(slidx->plat_specific_err, sp);
287		} else if (!efi_guidcmp(sp->guid,
288				SAL_PLAT_HOST_CTLR_ERR_SECT_GUID)) {
289			platform_err = 1;
290			LOG_INDEX_ADD_SECT_PTR(slidx->host_ctlr_err, sp);
291		} else if (!efi_guidcmp(sp->guid,
292				SAL_PLAT_BUS_ERR_SECT_GUID)) {
293			platform_err = 1;
294			LOG_INDEX_ADD_SECT_PTR(slidx->plat_bus_err, sp);
295		} else {
296			LOG_INDEX_ADD_SECT_PTR(slidx->unsupported, sp);
297		}
298	}
299	slidx->n_sections = sects;
300
301	return platform_err;
302}
303
304/**
305 * init_record_index_pools - Initialize pool of lists for SAL record index
306 *
307 * Return value:
308 *	0 on Success / -ENOMEM on Failure
309 */
310static int
311init_record_index_pools(void)
312{
313	int i;
314	int rec_max_size;  /* Maximum size of SAL error records */
315	int sect_min_size; /* Minimum size of SAL error sections */
316	/* minimum size table of each section */
317	static int sal_log_sect_min_sizes[] = {
318		sizeof(sal_log_processor_info_t)
319		+ sizeof(sal_processor_static_info_t),
320		sizeof(sal_log_mem_dev_err_info_t),
321		sizeof(sal_log_sel_dev_err_info_t),
322		sizeof(sal_log_pci_bus_err_info_t),
323		sizeof(sal_log_smbios_dev_err_info_t),
324		sizeof(sal_log_pci_comp_err_info_t),
325		sizeof(sal_log_plat_specific_err_info_t),
326		sizeof(sal_log_host_ctlr_err_info_t),
327		sizeof(sal_log_plat_bus_err_info_t),
328	};
329
330	/*
331	 * MCA handler cannot allocate new memory on flight,
332	 * so we preallocate enough memory to handle a SAL record.
333	 *
334	 * Initialize a handling set of slidx_pool:
335	 *   1. Pick up the max size of SAL error records
336	 *   2. Pick up the min size of SAL error sections
337	 *   3. Allocate the pool as enough to 2 SAL records
338	 *     (now we can estimate the maxinum of section in a record.)
339	 */
340
341	/* - 1 - */
342	rec_max_size = sal_rec_max;
343
344	/* - 2 - */
345	sect_min_size = sal_log_sect_min_sizes[0];
346	for (i = 1; i < sizeof sal_log_sect_min_sizes/sizeof(size_t); i++)
347		if (sect_min_size > sal_log_sect_min_sizes[i])
348			sect_min_size = sal_log_sect_min_sizes[i];
349
350	/* - 3 - */
351	slidx_pool.max_idx = (rec_max_size/sect_min_size) * 2 + 1;
352	slidx_pool.buffer =
353		kmalloc(slidx_pool.max_idx * sizeof(slidx_list_t), GFP_KERNEL);
354
355	return slidx_pool.buffer ? 0 : -ENOMEM;
356}
357
358
359/*****************************************************************************
360 * Recovery functions                                                        *
361 *****************************************************************************/
362
363/**
364 * is_mca_global - Check whether this MCA is global or not
365 * @peidx:	pointer of index of processor error section
366 * @pbci:	pointer to pal_bus_check_info_t
367 * @sos:	pointer to hand off struct between SAL and OS
368 *
369 * Return value:
370 *	MCA_IS_LOCAL / MCA_IS_GLOBAL
371 */
372
373static mca_type_t
374is_mca_global(peidx_table_t *peidx, pal_bus_check_info_t *pbci,
375	      struct ia64_sal_os_state *sos)
376{
377	pal_processor_state_info_t *psp =
378		(pal_processor_state_info_t*)peidx_psp(peidx);
379
380	/*
381	 * PAL can request a rendezvous, if the MCA has a global scope.
382	 * If "rz_always" flag is set, SAL requests MCA rendezvous
383	 * in spite of global MCA.
384	 * Therefore it is local MCA when rendezvous has not been requested.
385	 * Failed to rendezvous, the system must be down.
386	 */
387	switch (sos->rv_rc) {
388		case -1: /* SAL rendezvous unsuccessful */
389			return MCA_IS_GLOBAL;
390		case  0: /* SAL rendezvous not required */
391			return MCA_IS_LOCAL;
392		case  1: /* SAL rendezvous successful int */
393		case  2: /* SAL rendezvous successful int with init */
394		default:
395			break;
396	}
397
398	/*
399	 * If One or more Cache/TLB/Reg_File/Uarch_Check is here,
400	 * it would be a local MCA. (i.e. processor internal error)
401	 */
402	if (psp->tc || psp->cc || psp->rc || psp->uc)
403		return MCA_IS_LOCAL;
404
405	/*
406	 * Bus_Check structure with Bus_Check.ib (internal bus error) flag set
407	 * would be a global MCA. (e.g. a system bus address parity error)
408	 */
409	if (!pbci || pbci->ib)
410		return MCA_IS_GLOBAL;
411
412	/*
413	 * Bus_Check structure with Bus_Check.eb (external bus error) flag set
414	 * could be either a local MCA or a global MCA.
415	 *
416	 * Referring Bus_Check.bsi:
417	 *   0: Unknown/unclassified
418	 *   1: BERR#
419	 *   2: BINIT#
420	 *   3: Hard Fail
421	 * (FIXME: Are these SGI specific or generic bsi values?)
422	 */
423	if (pbci->eb)
424		switch (pbci->bsi) {
425			case 0:
426				/* e.g. a load from poisoned memory */
427				return MCA_IS_LOCAL;
428			case 1:
429			case 2:
430			case 3:
431				return MCA_IS_GLOBAL;
432		}
433
434	return MCA_IS_GLOBAL;
435}
436
437/**
438 * get_target_identifier - Get the valid Cache or Bus check target identifier.
439 * @peidx:	pointer of index of processor error section
440 *
441 * Return value:
442 *	target address on Success / 0 on Failure
443 */
444static u64
445get_target_identifier(peidx_table_t *peidx)
446{
447	u64 target_address = 0;
448	sal_log_mod_error_info_t *smei;
449	pal_cache_check_info_t *pcci;
450	int i, level = 9;
451
452	/*
453	 * Look through the cache checks for a valid target identifier
454	 * If more than one valid target identifier, return the one
455	 * with the lowest cache level.
456	 */
457	for (i = 0; i < peidx_cache_check_num(peidx); i++) {
458		smei = (sal_log_mod_error_info_t *)peidx_cache_check(peidx, i);
459		if (smei->valid.target_identifier && smei->target_identifier) {
460			pcci = (pal_cache_check_info_t *)&(smei->check_info);
461			if (!target_address || (pcci->level < level)) {
462				target_address = smei->target_identifier;
463				level = pcci->level;
464				continue;
465			}
466		}
467	}
468	if (target_address)
469		return target_address;
470
471	/*
472	 * Look at the bus check for a valid target identifier
473	 */
474	smei = peidx_bus_check(peidx, 0);
475	if (smei && smei->valid.target_identifier)
476		return smei->target_identifier;
477
478	return 0;
479}
480
481/**
482 * recover_from_read_error - Try to recover the errors which type are "read"s.
483 * @slidx:	pointer of index of SAL error record
484 * @peidx:	pointer of index of processor error section
485 * @pbci:	pointer of pal_bus_check_info
486 * @sos:	pointer to hand off struct between SAL and OS
487 *
488 * Return value:
489 *	1 on Success / 0 on Failure
490 */
491
492static int
493recover_from_read_error(slidx_table_t *slidx,
494			peidx_table_t *peidx, pal_bus_check_info_t *pbci,
495			struct ia64_sal_os_state *sos)
496{
497	u64 target_identifier;
498	pal_min_state_area_t *pmsa;
499	struct ia64_psr *psr1, *psr2;
500	ia64_fptr_t *mca_hdlr_bh = (ia64_fptr_t*)mca_handler_bhhook;
501
502	/* Is target address valid? */
503	target_identifier = get_target_identifier(peidx);
504	if (!target_identifier)
505		return fatal_mca("target address not valid");
506
507	/*
508	 * cpu read or memory-mapped io read
509	 *
510	 *    offending process  affected process  OS MCA do
511	 *     kernel mode        kernel mode       down system
512	 *     kernel mode        user   mode       kill the process
513	 *     user   mode        kernel mode       down system (*)
514	 *     user   mode        user   mode       kill the process
515	 *
516	 * (*) You could terminate offending user-mode process
517	 *    if (pbci->pv && pbci->pl != 0) *and* if you sure
518	 *    the process not have any locks of kernel.
519	 */
520
521	/* Is minstate valid? */
522	if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
523		return fatal_mca("minstate not valid");
524	psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
525	psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
526
527	/*
528	 *  Check the privilege level of interrupted context.
529	 *   If it is user-mode, then terminate affected process.
530	 */
531
532	pmsa = sos->pal_min_state;
533	if (psr1->cpl != 0 ||
534	   ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
535		/*
536		 *  setup for resume to bottom half of MCA,
537		 * "mca_handler_bhhook"
538		 */
539		/* pass to bhhook as argument (gr8, ...) */
540		pmsa->pmsa_gr[8-1] = target_identifier;
541		pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
542		pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
543		/* set interrupted return address (but no use) */
544		pmsa->pmsa_br0 = pmsa->pmsa_iip;
545		/* change resume address to bottom half */
546		pmsa->pmsa_iip = mca_hdlr_bh->fp;
547		pmsa->pmsa_gr[1-1] = mca_hdlr_bh->gp;
548		/* set cpl with kernel mode */
549		psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
550		psr2->cpl = 0;
551		psr2->ri  = 0;
552		psr2->bn  = 1;
553		psr2->i  = 0;
554
555		return mca_recovered("user memory corruption. "
556				"kill affected process - recovered.");
557	}
558
559	return fatal_mca("kernel context not recovered, iip 0x%lx\n",
560			 pmsa->pmsa_iip);
561}
562
563/**
564 * recover_from_platform_error - Recover from platform error.
565 * @slidx:	pointer of index of SAL error record
566 * @peidx:	pointer of index of processor error section
567 * @pbci:	pointer of pal_bus_check_info
568 * @sos:	pointer to hand off struct between SAL and OS
569 *
570 * Return value:
571 *	1 on Success / 0 on Failure
572 */
573
574static int
575recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
576			    pal_bus_check_info_t *pbci,
577			    struct ia64_sal_os_state *sos)
578{
579	int status = 0;
580	pal_processor_state_info_t *psp =
581		(pal_processor_state_info_t*)peidx_psp(peidx);
582
583	if (psp->bc && pbci->eb && pbci->bsi == 0) {
584		switch(pbci->type) {
585		case 1: /* partial read */
586		case 3: /* full line(cpu) read */
587		case 9: /* I/O space read */
588			status = recover_from_read_error(slidx, peidx, pbci,
589							 sos);
590			break;
591		case 0: /* unknown */
592		case 2: /* partial write */
593		case 4: /* full line write */
594		case 5: /* implicit or explicit write-back operation */
595		case 6: /* snoop probe */
596		case 7: /* incoming or outgoing ptc.g */
597		case 8: /* write coalescing transactions */
598		case 10: /* I/O space write */
599		case 11: /* inter-processor interrupt message(IPI) */
600		case 12: /* interrupt acknowledge or
601				external task priority cycle */
602		default:
603			break;
604		}
605	} else if (psp->cc && !psp->bc) {	/* Cache error */
606		status = recover_from_read_error(slidx, peidx, pbci, sos);
607	}
608
609	return status;
610}
611
612/*
613 * recover_from_tlb_check
614 * @peidx:	pointer of index of processor error section
615 *
616 * Return value:
617 *	1 on Success / 0 on Failure
618 */
619static int
620recover_from_tlb_check(peidx_table_t *peidx)
621{
622	sal_log_mod_error_info_t *smei;
623	pal_tlb_check_info_t *ptci;
624
625	smei = (sal_log_mod_error_info_t *)peidx_tlb_check(peidx, 0);
626	ptci = (pal_tlb_check_info_t *)&(smei->check_info);
627
628	/*
629	 * Look for signature of a duplicate TLB DTC entry, which is
630	 * a SW bug and always fatal.
631	 */
632	if (ptci->op == PAL_TLB_CHECK_OP_PURGE
633	    && !(ptci->itr || ptci->dtc || ptci->itc))
634		return fatal_mca("Duplicate TLB entry");
635
636	return mca_recovered("TLB check recovered");
637}
638
639/**
640 * recover_from_processor_error
641 * @platform:	whether there are some platform error section or not
642 * @slidx:	pointer of index of SAL error record
643 * @peidx:	pointer of index of processor error section
644 * @pbci:	pointer of pal_bus_check_info
645 * @sos:	pointer to hand off struct between SAL and OS
646 *
647 * Return value:
648 *	1 on Success / 0 on Failure
649 */
650
651static int
652recover_from_processor_error(int platform, slidx_table_t *slidx,
653			     peidx_table_t *peidx, pal_bus_check_info_t *pbci,
654			     struct ia64_sal_os_state *sos)
655{
656	pal_processor_state_info_t *psp =
657		(pal_processor_state_info_t*)peidx_psp(peidx);
658
659	/*
660	 * Processor recovery status must key off of the PAL recovery
661	 * status in the Processor State Parameter.
662	 */
663
664	/*
665	 * The machine check is corrected.
666	 */
667	if (psp->cm == 1)
668		return mca_recovered("machine check is already corrected.");
669
670	/*
671	 * The error was not contained.  Software must be reset.
672	 */
673	if (psp->us || psp->ci == 0)
674		return fatal_mca("error not contained");
675
676	/*
677	 * Look for recoverable TLB check
678	 */
679	if (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
680		return recover_from_tlb_check(peidx);
681
682	/*
683	 * The cache check and bus check bits have four possible states
684	 *   cc bc
685	 *    1  1	Memory error, attempt recovery
686	 *    1  0	Cache error, attempt recovery
687	 *    0  1	I/O error, attempt recovery
688	 *    0  0	Other error type, not recovered
689	 */
690	if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
691		return fatal_mca("No cache or bus check");
692
693	/*
694	 * Cannot handle more than one bus check.
695	 */
696	if (peidx_bus_check_num(peidx) > 1)
697		return fatal_mca("Too many bus checks");
698
699	if (pbci->ib)
700		return fatal_mca("Internal Bus error");
701	if (pbci->eb && pbci->bsi > 0)
702		return fatal_mca("External bus check fatal status");
703
704	/*
705	 * This is a local MCA and estimated as a recoverable error.
706	 */
707	if (platform)
708		return recover_from_platform_error(slidx, peidx, pbci, sos);
709
710	/*
711	 * On account of strange SAL error record, we cannot recover.
712	 */
713	return fatal_mca("Strange SAL record");
714}
715
716/**
717 * mca_try_to_recover - Try to recover from MCA
718 * @rec:	pointer to a SAL error record
719 * @sos:	pointer to hand off struct between SAL and OS
720 *
721 * Return value:
722 *	1 on Success / 0 on Failure
723 */
724
725static int
726mca_try_to_recover(void *rec, struct ia64_sal_os_state *sos)
727{
728	int platform_err;
729	int n_proc_err;
730	slidx_table_t slidx;
731	peidx_table_t peidx;
732	pal_bus_check_info_t pbci;
733
734	/* Make index of SAL error record */
735	platform_err = mca_make_slidx(rec, &slidx);
736
737	/* Count processor error sections */
738	n_proc_err = slidx_count(&slidx, proc_err);
739
740	 /* Now, OS can recover when there is one processor error section */
741	if (n_proc_err > 1)
742		return fatal_mca("Too Many Errors");
743	else if (n_proc_err == 0)
744		/* Weird SAL record ... We can't do anything */
745		return fatal_mca("Weird SAL record");
746
747	/* Make index of processor error section */
748	mca_make_peidx((sal_log_processor_info_t*)
749		slidx_first_entry(&slidx.proc_err)->hdr, &peidx);
750
751	/* Extract Processor BUS_CHECK[0] */
752	*((u64*)&pbci) = peidx_check_info(&peidx, bus_check, 0);
753
754	/* Check whether MCA is global or not */
755	if (is_mca_global(&peidx, &pbci, sos))
756		return fatal_mca("global MCA");
757
758	/* Try to recover a processor error */
759	return recover_from_processor_error(platform_err, &slidx, &peidx,
760					    &pbci, sos);
761}
762
763/*
764 * =============================================================================
765 */
766
767int __init mca_external_handler_init(void)
768{
769	if (init_record_index_pools())
770		return -ENOMEM;
771
772	/* register external mca handlers */
773	if (ia64_reg_MCA_extension(mca_try_to_recover)) {
774		printk(KERN_ERR "ia64_reg_MCA_extension failed.\n");
775		kfree(slidx_pool.buffer);
776		return -EFAULT;
777	}
778	return 0;
779}
780
781void __exit mca_external_handler_exit(void)
782{
783	/* unregister external mca handlers */
784	ia64_unreg_MCA_extension();
785	kfree(slidx_pool.buffer);
786}
787
788module_init(mca_external_handler_init);
789module_exit(mca_external_handler_exit);
790
791module_param(sal_rec_max, int, 0644);
792MODULE_PARM_DESC(sal_rec_max, "Max size of SAL error record");
793
794MODULE_DESCRIPTION("ia64 platform dependent mca handler driver");
795MODULE_LICENSE("GPL");
796