arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 0 insertions, 796 deletions

diff --git a/arch/ia64/kernel/mca_drv.c b/arch/ia64/kernel/mca_drv.c
deleted file mode 100644
index 23c203639a96..000000000000
--- a/arch/ia64/kernel/mca_drv.c
+++ /dev/null
@@ -1,796 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * File:	mca_drv.c
- * Purpose:	Generic MCA handling layer
- *
- * Copyright (C) 2004 FUJITSU LIMITED
- * Copyright (C) 2004 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
- * Copyright (C) 2005 Silicon Graphics, Inc
- * Copyright (C) 2005 Keith Owens <kaos@sgi.com>
- * Copyright (C) 2006 Russ Anderson <rja@sgi.com>
- */
-#include <linux/types.h>
-#include <linux/init.h>
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <linux/kallsyms.h>
-#include <linux/memblock.h>
-#include <linux/acpi.h>
-#include <linux/timer.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/smp.h>
-#include <linux/workqueue.h>
-#include <linux/mm.h>
-#include <linux/slab.h>
-
-#include <asm/delay.h>
-#include <asm/page.h>
-#include <asm/ptrace.h>
-#include <asm/sal.h>
-#include <asm/mca.h>
-
-#include <asm/irq.h>
-#include <asm/hw_irq.h>
-
-#include "mca_drv.h"
-
-/* max size of SAL error record (default) */
-static int sal_rec_max = 10000;
-
-/* from mca_drv_asm.S */
-extern void *mca_handler_bhhook(void);
-
-static DEFINE_SPINLOCK(mca_bh_lock);
-
-typedef enum {
-	MCA_IS_LOCAL  = 0,
-	MCA_IS_GLOBAL = 1
-} mca_type_t;
-
-#define MAX_PAGE_ISOLATE 1024
-
-static struct page *page_isolate[MAX_PAGE_ISOLATE];
-static int num_page_isolate = 0;
-
-typedef enum {
-	ISOLATE_NG,
-	ISOLATE_OK,
-	ISOLATE_NONE
-} isolate_status_t;
-
-typedef enum {
-	MCA_NOT_RECOVERED = 0,
-	MCA_RECOVERED	  = 1
-} recovery_status_t;
-
-/*
- *  This pool keeps pointers to the section part of SAL error record
- */
-static struct {
-	slidx_list_t *buffer; /* section pointer list pool */
-	int	     cur_idx; /* Current index of section pointer list pool */
-	int	     max_idx; /* Maximum index of section pointer list pool */
-} slidx_pool;
-
-static int
-fatal_mca(const char *fmt, ...)
-{
-	va_list args;
-	char buf[256];
-
-	va_start(args, fmt);
-	vsnprintf(buf, sizeof(buf), fmt, args);
-	va_end(args);
-	ia64_mca_printk(KERN_ALERT "MCA: %s\n", buf);
-
-	return MCA_NOT_RECOVERED;
-}
-
-static int
-mca_recovered(const char *fmt, ...)
-{
-	va_list args;
-	char buf[256];
-
-	va_start(args, fmt);
-	vsnprintf(buf, sizeof(buf), fmt, args);
-	va_end(args);
-	ia64_mca_printk(KERN_INFO "MCA: %s\n", buf);
-
-	return MCA_RECOVERED;
-}
-
-/**
- * mca_page_isolate - isolate a poisoned page in order not to use it later
- * @paddr:	poisoned memory location
- *
- * Return value:
- *	one of isolate_status_t, ISOLATE_OK/NG/NONE.
- */
-
-static isolate_status_t
-mca_page_isolate(unsigned long paddr)
-{
-	int i;
-	struct page *p;
-
-	/* whether physical address is valid or not */
-	if (!ia64_phys_addr_valid(paddr))
-		return ISOLATE_NONE;
-
-	if (!pfn_valid(paddr >> PAGE_SHIFT))
-		return ISOLATE_NONE;
-
-	/* convert physical address to physical page number */
-	p = pfn_to_page(paddr>>PAGE_SHIFT);
-
-	/* check whether a page number have been already registered or not */
-	for (i = 0; i < num_page_isolate; i++)
-		if (page_isolate[i] == p)
-			return ISOLATE_OK; /* already listed */
-
-	/* limitation check */
-	if (num_page_isolate == MAX_PAGE_ISOLATE)
-		return ISOLATE_NG;
-
-	/* kick pages having attribute 'SLAB' or 'Reserved' */
-	if (PageSlab(p) || PageReserved(p))
-		return ISOLATE_NG;
-
-	/* add attribute 'Reserved' and register the page */
-	get_page(p);
-	SetPageReserved(p);
-	page_isolate[num_page_isolate++] = p;
-
-	return ISOLATE_OK;
-}
-
-/**
- * mca_hanlder_bh - Kill the process which occurred memory read error
- * @paddr:	poisoned address received from MCA Handler
- */
-
-void
-mca_handler_bh(unsigned long paddr, void *iip, unsigned long ipsr)
-{
-	ia64_mlogbuf_dump();
-	printk(KERN_ERR "OS_MCA: process [cpu %d, pid: %d, uid: %d, "
-		"iip: %p, psr: 0x%lx,paddr: 0x%lx](%s) encounters MCA.\n",
-	       raw_smp_processor_id(), current->pid,
-		from_kuid(&init_user_ns, current_uid()),
-		iip, ipsr, paddr, current->comm);
-
-	spin_lock(&mca_bh_lock);
-	switch (mca_page_isolate(paddr)) {
-	case ISOLATE_OK:
-		printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
-		break;
-	case ISOLATE_NG:
-		printk(KERN_CRIT "Page isolation: ( %lx ) failure.\n", paddr);
-		break;
-	default:
-		break;
-	}
-	spin_unlock(&mca_bh_lock);
-
-	/* This process is about to be killed itself */
-	make_task_dead(SIGKILL);
-}
-
-/**
- * mca_make_peidx - Make index of processor error section
- * @slpi:	pointer to record of processor error section
- * @peidx:	pointer to index of processor error section
- */
-
-static void
-mca_make_peidx(sal_log_processor_info_t *slpi, peidx_table_t *peidx)
-{
-	/*
-	 * calculate the start address of
-	 *   "struct cpuid_info" and "sal_processor_static_info_t".
-	 */
-	u64 total_check_num = slpi->valid.num_cache_check
-				+ slpi->valid.num_tlb_check
-				+ slpi->valid.num_bus_check
-				+ slpi->valid.num_reg_file_check
-				+ slpi->valid.num_ms_check;
-	u64 head_size =	sizeof(sal_log_mod_error_info_t) * total_check_num
-			+ sizeof(sal_log_processor_info_t);
-	u64 mid_size  = slpi->valid.cpuid_info * sizeof(struct sal_cpuid_info);
-
-	peidx_head(peidx)   = slpi;
-	peidx_mid(peidx)    = (struct sal_cpuid_info *)
-		(slpi->valid.cpuid_info ? ((char*)slpi + head_size) : NULL);
-	peidx_bottom(peidx) = (sal_processor_static_info_t *)
-		(slpi->valid.psi_static_struct ?
-			((char*)slpi + head_size + mid_size) : NULL);
-}
-
-/**
- * mca_make_slidx -  Make index of SAL error record
- * @buffer:	pointer to SAL error record
- * @slidx:	pointer to index of SAL error record
- *
- * Return value:
- *	1 if record has platform error / 0 if not
- */
-#define LOG_INDEX_ADD_SECT_PTR(sect, ptr) \
-	{slidx_list_t *hl = &slidx_pool.buffer[slidx_pool.cur_idx]; \
-	hl->hdr = ptr; \
-	list_add(&hl->list, &(sect)); \
-	slidx_pool.cur_idx = (slidx_pool.cur_idx + 1)%slidx_pool.max_idx; }
-
-static int
-mca_make_slidx(void *buffer, slidx_table_t *slidx)
-{
-	int platform_err = 0;
-	int record_len = ((sal_log_record_header_t*)buffer)->len;
-	u32 ercd_pos;
-	int sects;
-	sal_log_section_hdr_t *sp;
-
-	/*
-	 * Initialize index referring current record
-	 */
-	INIT_LIST_HEAD(&(slidx->proc_err));
-	INIT_LIST_HEAD(&(slidx->mem_dev_err));
-	INIT_LIST_HEAD(&(slidx->sel_dev_err));
-	INIT_LIST_HEAD(&(slidx->pci_bus_err));
-	INIT_LIST_HEAD(&(slidx->smbios_dev_err));
-	INIT_LIST_HEAD(&(slidx->pci_comp_err));
-	INIT_LIST_HEAD(&(slidx->plat_specific_err));
-	INIT_LIST_HEAD(&(slidx->host_ctlr_err));
-	INIT_LIST_HEAD(&(slidx->plat_bus_err));
-	INIT_LIST_HEAD(&(slidx->unsupported));
-
-	/*
-	 * Extract a Record Header
-	 */
-	slidx->header = buffer;
-
-	/*
-	 * Extract each section records
-	 * (arranged from "int ia64_log_platform_info_print()")
-	 */
-	for (ercd_pos = sizeof(sal_log_record_header_t), sects = 0;
-		ercd_pos < record_len; ercd_pos += sp->len, sects++) {
-		sp = (sal_log_section_hdr_t *)((char*)buffer + ercd_pos);
-		if (!efi_guidcmp(sp->guid, SAL_PROC_DEV_ERR_SECT_GUID)) {
-			LOG_INDEX_ADD_SECT_PTR(slidx->proc_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_MEM_DEV_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->mem_dev_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_SEL_DEV_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->sel_dev_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_PCI_BUS_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->pci_bus_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_SMBIOS_DEV_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->smbios_dev_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_PCI_COMP_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->pci_comp_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_SPECIFIC_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->plat_specific_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_HOST_CTLR_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->host_ctlr_err, sp);
-		} else if (!efi_guidcmp(sp->guid,
-				SAL_PLAT_BUS_ERR_SECT_GUID)) {
-			platform_err = 1;
-			LOG_INDEX_ADD_SECT_PTR(slidx->plat_bus_err, sp);
-		} else {
-			LOG_INDEX_ADD_SECT_PTR(slidx->unsupported, sp);
-		}
-	}
-	slidx->n_sections = sects;
-
-	return platform_err;
-}
-
-/**
- * init_record_index_pools - Initialize pool of lists for SAL record index
- *
- * Return value:
- *	0 on Success / -ENOMEM on Failure
- */
-static int
-init_record_index_pools(void)
-{
-	int i;
-	int rec_max_size;  /* Maximum size of SAL error records */
-	int sect_min_size; /* Minimum size of SAL error sections */
-	/* minimum size table of each section */
-	static int sal_log_sect_min_sizes[] = {
-		sizeof(sal_log_processor_info_t)
-		+ sizeof(sal_processor_static_info_t),
-		sizeof(sal_log_mem_dev_err_info_t),
-		sizeof(sal_log_sel_dev_err_info_t),
-		sizeof(sal_log_pci_bus_err_info_t),
-		sizeof(sal_log_smbios_dev_err_info_t),
-		sizeof(sal_log_pci_comp_err_info_t),
-		sizeof(sal_log_plat_specific_err_info_t),
-		sizeof(sal_log_host_ctlr_err_info_t),
-		sizeof(sal_log_plat_bus_err_info_t),
-	};
-
-	/*
-	 * MCA handler cannot allocate new memory on flight,
-	 * so we preallocate enough memory to handle a SAL record.
-	 *
-	 * Initialize a handling set of slidx_pool:
-	 *   1. Pick up the max size of SAL error records
-	 *   2. Pick up the min size of SAL error sections
-	 *   3. Allocate the pool as enough to 2 SAL records
-	 *     (now we can estimate the maxinum of section in a record.)
-	 */
-
-	/* - 1 - */
-	rec_max_size = sal_rec_max;
-
-	/* - 2 - */
-	sect_min_size = sal_log_sect_min_sizes[0];
-	for (i = 1; i < ARRAY_SIZE(sal_log_sect_min_sizes); i++)
-		if (sect_min_size > sal_log_sect_min_sizes[i])
-			sect_min_size = sal_log_sect_min_sizes[i];
-
-	/* - 3 - */
-	slidx_pool.max_idx = (rec_max_size/sect_min_size) * 2 + 1;
-	slidx_pool.buffer =
-		kmalloc_array(slidx_pool.max_idx, sizeof(slidx_list_t),
-			      GFP_KERNEL);
-
-	return slidx_pool.buffer ? 0 : -ENOMEM;
-}
-
-
-/*****************************************************************************
- * Recovery functions                                                        *
- *****************************************************************************/
-
-/**
- * is_mca_global - Check whether this MCA is global or not
- * @peidx:	pointer of index of processor error section
- * @pbci:	pointer to pal_bus_check_info_t
- * @sos:	pointer to hand off struct between SAL and OS
- *
- * Return value:
- *	MCA_IS_LOCAL / MCA_IS_GLOBAL
- */
-
-static mca_type_t
-is_mca_global(peidx_table_t *peidx, pal_bus_check_info_t *pbci,
-	      struct ia64_sal_os_state *sos)
-{
-	pal_processor_state_info_t *psp =
-		(pal_processor_state_info_t*)peidx_psp(peidx);
-
-	/*
-	 * PAL can request a rendezvous, if the MCA has a global scope.
-	 * If "rz_always" flag is set, SAL requests MCA rendezvous
-	 * in spite of global MCA.
-	 * Therefore it is local MCA when rendezvous has not been requested.
-	 * Failed to rendezvous, the system must be down.
-	 */
-	switch (sos->rv_rc) {
-		case -1: /* SAL rendezvous unsuccessful */
-			return MCA_IS_GLOBAL;
-		case  0: /* SAL rendezvous not required */
-			return MCA_IS_LOCAL;
-		case  1: /* SAL rendezvous successful int */
-		case  2: /* SAL rendezvous successful int with init */
-		default:
-			break;
-	}
-
-	/*
-	 * If One or more Cache/TLB/Reg_File/Uarch_Check is here,
-	 * it would be a local MCA. (i.e. processor internal error)
-	 */
-	if (psp->tc || psp->cc || psp->rc || psp->uc)
-		return MCA_IS_LOCAL;
-	
-	/*
-	 * Bus_Check structure with Bus_Check.ib (internal bus error) flag set
-	 * would be a global MCA. (e.g. a system bus address parity error)
-	 */
-	if (!pbci || pbci->ib)
-		return MCA_IS_GLOBAL;
-
-	/*
-	 * Bus_Check structure with Bus_Check.eb (external bus error) flag set
-	 * could be either a local MCA or a global MCA.
-	 *
-	 * Referring Bus_Check.bsi:
-	 *   0: Unknown/unclassified
-	 *   1: BERR#
-	 *   2: BINIT#
-	 *   3: Hard Fail
-	 * (FIXME: Are these SGI specific or generic bsi values?)
-	 */
-	if (pbci->eb)
-		switch (pbci->bsi) {
-			case 0:
-				/* e.g. a load from poisoned memory */
-				return MCA_IS_LOCAL;
-			case 1:
-			case 2:
-			case 3:
-				return MCA_IS_GLOBAL;
-		}
-
-	return MCA_IS_GLOBAL;
-}
-
-/**
- * get_target_identifier - Get the valid Cache or Bus check target identifier.
- * @peidx:	pointer of index of processor error section
- *
- * Return value:
- *	target address on Success / 0 on Failure
- */
-static u64
-get_target_identifier(peidx_table_t *peidx)
-{
-	u64 target_address = 0;
-	sal_log_mod_error_info_t *smei;
-	pal_cache_check_info_t *pcci;
-	int i, level = 9;
-
-	/*
-	 * Look through the cache checks for a valid target identifier
-	 * If more than one valid target identifier, return the one
-	 * with the lowest cache level.
-	 */
-	for (i = 0; i < peidx_cache_check_num(peidx); i++) {
-		smei = (sal_log_mod_error_info_t *)peidx_cache_check(peidx, i);
-		if (smei->valid.target_identifier && smei->target_identifier) {
-			pcci = (pal_cache_check_info_t *)&(smei->check_info);
-			if (!target_address || (pcci->level < level)) {
-				target_address = smei->target_identifier;
-				level = pcci->level;
-				continue;
-			}
-		}
-	}
-	if (target_address)
-		return target_address;
-
-	/*
-	 * Look at the bus check for a valid target identifier
-	 */
-	smei = peidx_bus_check(peidx, 0);
-	if (smei && smei->valid.target_identifier)
-		return smei->target_identifier;
-
-	return 0;
-}
-
-/**
- * recover_from_read_error - Try to recover the errors which type are "read"s.
- * @slidx:	pointer of index of SAL error record
- * @peidx:	pointer of index of processor error section
- * @pbci:	pointer of pal_bus_check_info
- * @sos:	pointer to hand off struct between SAL and OS
- *
- * Return value:
- *	1 on Success / 0 on Failure
- */
-
-static int
-recover_from_read_error(slidx_table_t *slidx,
-			peidx_table_t *peidx, pal_bus_check_info_t *pbci,
-			struct ia64_sal_os_state *sos)
-{
-	u64 target_identifier;
-	struct pal_min_state_area *pmsa;
-	struct ia64_psr *psr1, *psr2;
-	ia64_fptr_t *mca_hdlr_bh = (ia64_fptr_t*)mca_handler_bhhook;
-
-	/* Is target address valid? */
-	target_identifier = get_target_identifier(peidx);
-	if (!target_identifier)
-		return fatal_mca("target address not valid");
-
-	/*
-	 * cpu read or memory-mapped io read
-	 *
-	 *    offending process  affected process  OS MCA do
-	 *     kernel mode        kernel mode       down system
-	 *     kernel mode        user   mode       kill the process
-	 *     user   mode        kernel mode       down system (*)
-	 *     user   mode        user   mode       kill the process
-	 *
-	 * (*) You could terminate offending user-mode process
-	 *    if (pbci->pv && pbci->pl != 0) *and* if you sure
-	 *    the process not have any locks of kernel.
-	 */
-
-	/* Is minstate valid? */
-	if (!peidx_bottom(peidx) || !(peidx_bottom(peidx)->valid.minstate))
-		return fatal_mca("minstate not valid");
-	psr1 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_ipsr);
-	psr2 =(struct ia64_psr *)&(peidx_minstate_area(peidx)->pmsa_xpsr);
-
-	/*
-	 *  Check the privilege level of interrupted context.
-	 *   If it is user-mode, then terminate affected process.
-	 */
-
-	pmsa = sos->pal_min_state;
-	if (psr1->cpl != 0 ||
-	   ((psr2->cpl != 0) && mca_recover_range(pmsa->pmsa_iip))) {
-		/*
-		 *  setup for resume to bottom half of MCA,
-		 * "mca_handler_bhhook"
-		 */
-		/* pass to bhhook as argument (gr8, ...) */
-		pmsa->pmsa_gr[8-1] = target_identifier;
-		pmsa->pmsa_gr[9-1] = pmsa->pmsa_iip;
-		pmsa->pmsa_gr[10-1] = pmsa->pmsa_ipsr;
-		/* set interrupted return address (but no use) */
-		pmsa->pmsa_br0 = pmsa->pmsa_iip;
-		/* change resume address to bottom half */
-		pmsa->pmsa_iip = mca_hdlr_bh->fp;
-		pmsa->pmsa_gr[1-1] = mca_hdlr_bh->gp;
-		/* set cpl with kernel mode */
-		psr2 = (struct ia64_psr *)&pmsa->pmsa_ipsr;
-		psr2->cpl = 0;
-		psr2->ri  = 0;
-		psr2->bn  = 1;
-		psr2->i  = 0;
-
-		return mca_recovered("user memory corruption. "
-				"kill affected process - recovered.");
-	}
-
-	return fatal_mca("kernel context not recovered, iip 0x%lx\n",
-			 pmsa->pmsa_iip);
-}
-
-/**
- * recover_from_platform_error - Recover from platform error.
- * @slidx:	pointer of index of SAL error record
- * @peidx:	pointer of index of processor error section
- * @pbci:	pointer of pal_bus_check_info
- * @sos:	pointer to hand off struct between SAL and OS
- *
- * Return value:
- *	1 on Success / 0 on Failure
- */
-
-static int
-recover_from_platform_error(slidx_table_t *slidx, peidx_table_t *peidx,
-			    pal_bus_check_info_t *pbci,
-			    struct ia64_sal_os_state *sos)
-{
-	int status = 0;
-	pal_processor_state_info_t *psp =
-		(pal_processor_state_info_t*)peidx_psp(peidx);
-
-	if (psp->bc && pbci->eb && pbci->bsi == 0) {
-		switch(pbci->type) {
-		case 1: /* partial read */
-		case 3: /* full line(cpu) read */
-		case 9: /* I/O space read */
-			status = recover_from_read_error(slidx, peidx, pbci,
-							 sos);
-			break;
-		case 0: /* unknown */
-		case 2: /* partial write */
-		case 4: /* full line write */
-		case 5: /* implicit or explicit write-back operation */
-		case 6: /* snoop probe */
-		case 7: /* incoming or outgoing ptc.g */
-		case 8: /* write coalescing transactions */
-		case 10: /* I/O space write */
-		case 11: /* inter-processor interrupt message(IPI) */
-		case 12: /* interrupt acknowledge or
-				external task priority cycle */
-		default:
-			break;
-		}
-	} else if (psp->cc && !psp->bc) {	/* Cache error */
-		status = recover_from_read_error(slidx, peidx, pbci, sos);
-	}
-
-	return status;
-}
-
-/*
- * recover_from_tlb_check
- * @peidx:	pointer of index of processor error section
- *
- * Return value:
- *	1 on Success / 0 on Failure
- */
-static int
-recover_from_tlb_check(peidx_table_t *peidx)
-{
-	sal_log_mod_error_info_t *smei;
-	pal_tlb_check_info_t *ptci;
-
-	smei = (sal_log_mod_error_info_t *)peidx_tlb_check(peidx, 0);
-	ptci = (pal_tlb_check_info_t *)&(smei->check_info);
-
-	/*
-	 * Look for signature of a duplicate TLB DTC entry, which is
-	 * a SW bug and always fatal.
-	 */
-	if (ptci->op == PAL_TLB_CHECK_OP_PURGE
-	    && !(ptci->itr || ptci->dtc || ptci->itc))
-		return fatal_mca("Duplicate TLB entry");
-
-	return mca_recovered("TLB check recovered");
-}
-
-/**
- * recover_from_processor_error
- * @platform:	whether there are some platform error section or not
- * @slidx:	pointer of index of SAL error record
- * @peidx:	pointer of index of processor error section
- * @pbci:	pointer of pal_bus_check_info
- * @sos:	pointer to hand off struct between SAL and OS
- *
- * Return value:
- *	1 on Success / 0 on Failure
- */
-
-static int
-recover_from_processor_error(int platform, slidx_table_t *slidx,
-			     peidx_table_t *peidx, pal_bus_check_info_t *pbci,
-			     struct ia64_sal_os_state *sos)
-{
-	pal_processor_state_info_t *psp =
-		(pal_processor_state_info_t*)peidx_psp(peidx);
-
-	/*
-	 * Processor recovery status must key off of the PAL recovery
-	 * status in the Processor State Parameter.
-	 */
-
-	/*
-	 * The machine check is corrected.
-	 */
-	if (psp->cm == 1)
-		return mca_recovered("machine check is already corrected.");
-
-	/*
-	 * The error was not contained.  Software must be reset.
-	 */
-	if (psp->us || psp->ci == 0)
-		return fatal_mca("error not contained");
-
-	/*
-	 * Look for recoverable TLB check
-	 */
-	if (psp->tc && !(psp->cc || psp->bc || psp->rc || psp->uc))
-		return recover_from_tlb_check(peidx);
-
-	/*
-	 * The cache check and bus check bits have four possible states
-	 *   cc bc
-	 *    1  1	Memory error, attempt recovery
-	 *    1  0	Cache error, attempt recovery
-	 *    0  1	I/O error, attempt recovery
-	 *    0  0	Other error type, not recovered
-	 */
-	if (psp->cc == 0 && (psp->bc == 0 || pbci == NULL))
-		return fatal_mca("No cache or bus check");
-
-	/*
-	 * Cannot handle more than one bus check.
-	 */
-	if (peidx_bus_check_num(peidx) > 1)
-		return fatal_mca("Too many bus checks");
-
-	if (pbci->ib)
-		return fatal_mca("Internal Bus error");
-	if (pbci->eb && pbci->bsi > 0)
-		return fatal_mca("External bus check fatal status");
-
-	/*
-	 * This is a local MCA and estimated as a recoverable error.
-	 */
-	if (platform)
-		return recover_from_platform_error(slidx, peidx, pbci, sos);
-
-	/*
-	 * On account of strange SAL error record, we cannot recover.
-	 */
-	return fatal_mca("Strange SAL record");
-}
-
-/**
- * mca_try_to_recover - Try to recover from MCA
- * @rec:	pointer to a SAL error record
- * @sos:	pointer to hand off struct between SAL and OS
- *
- * Return value:
- *	1 on Success / 0 on Failure
- */
-
-static int
-mca_try_to_recover(void *rec, struct ia64_sal_os_state *sos)
-{
-	int platform_err;
-	int n_proc_err;
-	slidx_table_t slidx;
-	peidx_table_t peidx;
-	pal_bus_check_info_t pbci;
-
-	/* Make index of SAL error record */
-	platform_err = mca_make_slidx(rec, &slidx);
-
-	/* Count processor error sections */
-	n_proc_err = slidx_count(&slidx, proc_err);
-
-	 /* Now, OS can recover when there is one processor error section */
-	if (n_proc_err > 1)
-		return fatal_mca("Too Many Errors");
-	else if (n_proc_err == 0)
-		/* Weird SAL record ... We can't do anything */
-		return fatal_mca("Weird SAL record");
-
-	/* Make index of processor error section */
-	mca_make_peidx((sal_log_processor_info_t*)
-		slidx_first_entry(&slidx.proc_err)->hdr, &peidx);
-
-	/* Extract Processor BUS_CHECK[0] */
-	*((u64*)&pbci) = peidx_check_info(&peidx, bus_check, 0);
-
-	/* Check whether MCA is global or not */
-	if (is_mca_global(&peidx, &pbci, sos))
-		return fatal_mca("global MCA");
-	
-	/* Try to recover a processor error */
-	return recover_from_processor_error(platform_err, &slidx, &peidx,
-					    &pbci, sos);
-}
-
-/*
- * =============================================================================
- */
-
-int __init mca_external_handler_init(void)
-{
-	if (init_record_index_pools())
-		return -ENOMEM;
-
-	/* register external mca handlers */
-	if (ia64_reg_MCA_extension(mca_try_to_recover)) {	
-		printk(KERN_ERR "ia64_reg_MCA_extension failed.\n");
-		kfree(slidx_pool.buffer);
-		return -EFAULT;
-	}
-	return 0;
-}
-
-void __exit mca_external_handler_exit(void)
-{
-	/* unregister external mca handlers */
-	ia64_unreg_MCA_extension();
-	kfree(slidx_pool.buffer);
-}
-
-module_init(mca_external_handler_init);
-module_exit(mca_external_handler_exit);
-
-module_param(sal_rec_max, int, 0644);
-MODULE_PARM_DESC(sal_rec_max, "Max size of SAL error record");
-
-MODULE_DESCRIPTION("ia64 platform dependent mca handler driver");
-MODULE_LICENSE("GPL");