mca.c

linux-2.6.15.6

/*
 * File:	mca.c
 * Purpose:	Generic MCA handling layer
 *
 * Updated for latest kernel
 * Copyright (C) 2003 Hewlett-Packard Co
 *	David Mosberger-Tang <[e-mail]>
 *
 * Copyright (C) 2002 Dell Inc.
 * Copyright (C) Matt Domsch ([e-mail])
 *
 * Copyright (C) 2002 Intel
 * Copyright (C) Jenna Hall ([e-mail])
 *
 * Copyright (C) 2001 Intel
 * Copyright (C) Fred Lewis ([e-mail])
 *
 * Copyright (C) 2000 Intel
 * Copyright (C) Chuck Fleckenstein ([e-mail])
 *
 * Copyright (C) 1999, 2004 Silicon Graphics, Inc.
 * Copyright (C) Vijay Chander([e-mail])
 *
 * 03/04/15 D. Mosberger Added INIT backtrace support.
 * 02/03/25 M. Domsch	GUID cleanups
 *
 * 02/01/04 J. Hall	Aligned MCA stack to 16 bytes, added platform vs. CPU
 *			error flag, set SAL default return values, changed
 *			error record structure to linked list, added init call
 *			to sal_get_state_info_size().
 *
 * 01/01/03 F. Lewis    Added setup of CMCI and CPEI IRQs, logging of corrected
 *                      platform errors, completed code for logging of
 *                      corrected & uncorrected machine check errors, and
 *                      updated for conformance with Nov. 2000 revision of the
 *                      SAL 3.0 spec.
 * 00/03/29 C. Fleckenstein  Fixed PAL/SAL update issues, began MCA bug fixes, logging issues,
 *                           added min save state dump, added INIT handler.
 *
 * 2003-12-08 Keith Owens <[e-mail]>
 *            smp_call_function() must not be called from interrupt context (can
 *            deadlock on tasklist_lock).  Use keventd to call smp_call_function().
 *
 * 2004-02-01 Keith Owens <[e-mail]>
 *            Avoid deadlock when using printk() for MCA and INIT records.
 *            Delete all record printing code, moved to salinfo_decode in user space.
 *            Mark variables and functions static where possible.
 *            Delete dead variables and functions.
 *            Reorder to remove the need for forward declarations and to consolidate
 *            related code.
 *
 * 2005-08-12 Keith Owens <[e-mail]>
 *	      Convert MCA/INIT handlers to use per event stacks and SAL/OS state.
 *
 * 2005-10-07 Keith Owens <[e-mail]>
 *	      Add notify_die() hooks.
 */
#include <linux/config.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/smp_lock.h>
#include <linux/bootmem.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 <asm/delay.h>
#include <asm/kdebug.h>
#include <asm/machvec.h>
#include <asm/meminit.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/system.h>
#include <asm/sal.h>
#include <asm/mca.h>

#include <asm/irq.h>
#include <asm/hw_irq.h>

#include "entry.h"

#if defined(IA64_MCA_DEBUG_INFO)
# define IA64_MCA_DEBUG(fmt...)	printk(fmt)
#else
# define IA64_MCA_DEBUG(fmt...)
#endif

/* Used by mca_asm.S */
u32				ia64_mca_serialize;
DEFINE_PER_CPU(u64, ia64_mca_data); /* == __per_cpu_mca[smp_processor_id()] */
DEFINE_PER_CPU(u64, ia64_mca_per_cpu_pte); /* PTE to map per-CPU area */
DEFINE_PER_CPU(u64, ia64_mca_pal_pte);	    /* PTE to map PAL code */
DEFINE_PER_CPU(u64, ia64_mca_pal_base);    /* vaddr PAL code granule */

unsigned long __per_cpu_mca[NR_CPUS];

/* In mca_asm.S */
extern void			ia64_os_init_dispatch_monarch (void);
extern void			ia64_os_init_dispatch_slave (void);

static int monarch_cpu = -1;

static ia64_mc_info_t		ia64_mc_info;

#define MAX_CPE_POLL_INTERVAL (15*60*HZ) /* 15 minutes */
#define MIN_CPE_POLL_INTERVAL (2*60*HZ)  /* 2 minutes */
#define CMC_POLL_INTERVAL     (1*60*HZ)  /* 1 minute */
#define CPE_HISTORY_LENGTH    5
#define CMC_HISTORY_LENGTH    5

static struct timer_list cpe_poll_timer;
static struct timer_list cmc_poll_timer;
/*
 * This variable tells whether we are currently in polling mode.
 * Start with this in the wrong state so we won't play w/ timers
 * before the system is ready.
 */
static int cmc_polling_enabled = 1;

/*
 * Clearing this variable prevents CPE polling from getting activated
 * in mca_late_init.  Use it if your system doesn't provide a CPEI,
 * but encounters problems retrieving CPE logs.  This should only be
 * necessary for debugging.
 */
static int cpe_poll_enabled = 1;

extern void salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe);

static int mca_init;


static void inline
ia64_mca_spin(const char *func)
{
	printk(KERN_EMERG "%s: spinning here, not returning to SAL\n", func);
	while (1)
		cpu_relax();
}
/*
 * IA64_MCA log support
 */
#define IA64_MAX_LOGS		2	/* Double-buffering for nested MCAs */
#define IA64_MAX_LOG_TYPES      4   /* MCA, INIT, CMC, CPE */

typedef struct ia64_state_log_s
{
	spinlock_t	isl_lock;
	int		isl_index;
	unsigned long	isl_count;
	ia64_err_rec_t  *isl_log[IA64_MAX_LOGS]; /* need space to store header + error log */
} ia64_state_log_t;

static ia64_state_log_t ia64_state_log[IA64_MAX_LOG_TYPES];

#define IA64_LOG_ALLOCATE(it, size) \
	{ia64_state_log[it].isl_log[IA64_LOG_CURR_INDEX(it)] = \
		(ia64_err_rec_t *)alloc_bootmem(size); \
	ia64_state_log[it].isl_log[IA64_LOG_NEXT_INDEX(it)] = \
		(ia64_err_rec_t *)alloc_bootmem(size);}
#define IA64_LOG_LOCK_INIT(it) spin_lock_init(&ia64_state_log[it].isl_lock)
#define IA64_LOG_LOCK(it)      spin_lock_irqsave(&ia64_state_log[it].isl_lock, s)
#define IA64_LOG_UNLOCK(it)    spin_unlock_irqrestore(&ia64_state_log[it].isl_lock,s)
#define IA64_LOG_NEXT_INDEX(it)    ia64_state_log[it].isl_index
#define IA64_LOG_CURR_INDEX(it)    1 - ia64_state_log[it].isl_index
#define IA64_LOG_INDEX_INC(it) \
    {ia64_state_log[it].isl_index = 1 - ia64_state_log[it].isl_index; \
    ia64_state_log[it].isl_count++;}
#define IA64_LOG_INDEX_DEC(it) \
    ia64_state_log[it].isl_index = 1 - ia64_state_log[it].isl_index
#define IA64_LOG_NEXT_BUFFER(it)   (void *)((ia64_state_log[it].isl_log[IA64_LOG_NEXT_INDEX(it)]))
#define IA64_LOG_CURR_BUFFER(it)   (void *)((ia64_state_log[it].isl_log[IA64_LOG_CURR_INDEX(it)]))
#define IA64_LOG_COUNT(it)         ia64_state_log[it].isl_count

/*
 * ia64_log_init
 *	Reset the OS ia64 log buffer
 * Inputs   :   info_type   (SAL_INFO_TYPE_{MCA,INIT,CMC,CPE})
 * Outputs	:	None
 */
static void
ia64_log_init(int sal_info_type)
{
	u64	max_size = 0;

	IA64_LOG_NEXT_INDEX(sal_info_type) = 0;
	IA64_LOG_LOCK_INIT(sal_info_type);

	// SAL will tell us the maximum size of any error record of this type
	max_size = ia64_sal_get_state_info_size(sal_info_type);
	if (!max_size)
		/* alloc_bootmem() doesn't like zero-sized allocations! */
		return;

	// set up OS data structures to hold error info
	IA64_LOG_ALLOCATE(sal_info_type, max_size);
	memset(IA64_LOG_CURR_BUFFER(sal_info_type), 0, max_size);
	memset(IA64_LOG_NEXT_BUFFER(sal_info_type), 0, max_size);
}

/*
 * ia64_log_get
 *
 *	Get the current MCA log from SAL and copy it into the OS log buffer.
 *
 *  Inputs  :   info_type   (SAL_INFO_TYPE_{MCA,INIT,CMC,CPE})
 *              irq_safe    whether you can use printk at this point
 *  Outputs :   size        (total record length)
 *              *buffer     (ptr to error record)
 *
 */
static u64
ia64_log_get(int sal_info_type, u8 **buffer, int irq_safe)
{
	sal_log_record_header_t     *log_buffer;
	u64                         total_len = 0;
	int                         s;

	IA64_LOG_LOCK(sal_info_type);

	/* Get the process state information */
	log_buffer = IA64_LOG_NEXT_BUFFER(sal_info_type);

	total_len = ia64_sal_get_state_info(sal_info_type, (u64 *)log_buffer);

	if (total_len) {
		IA64_LOG_INDEX_INC(sal_info_type);
		IA64_LOG_UNLOCK(sal_info_type);
		if (irq_safe) {
			IA64_MCA_DEBUG("%s: SAL error record type %d retrieved. "
				       "Record length = %ld\n", __FUNCTION__, sal_info_type, total_len);
		}
		*buffer = (u8 *) log_buffer;
		return total_len;
	} else {
		IA64_LOG_UNLOCK(sal_info_type);
		return 0;
	}
}

/*
 *  ia64_mca_log_sal_error_record
 *
 *  This function retrieves a specified error record type from SAL
 *  and wakes up any processes waiting for error records.
 *
 *  Inputs  :   sal_info_type   (Type of error record MCA/CMC/CPE)
 *              FIXME: remove MCA and irq_safe.
 */
static void
ia64_mca_log_sal_error_record(int sal_info_type)
{
	u8 *buffer;
	sal_log_record_header_t *rh;
	u64 size;
	int irq_safe = sal_info_type != SAL_INFO_TYPE_MCA;
#ifdef IA64_MCA_DEBUG_INFO
	static const char * const rec_name[] = { "MCA", "INIT", "CMC", "CPE" };
#endif

	size = ia64_log_get(sal_info_type, &buffer, irq_safe);
	if (!size)
		return;

	salinfo_log_wakeup(sal_info_type, buffer, size, irq_safe);

	if (irq_safe)
		IA64_MCA_DEBUG("CPU %d: SAL log contains %s error record\n",
			smp_processor_id(),
			sal_info_type < ARRAY_SIZE(rec_name) ? rec_name[sal_info_type] : "UNKNOWN");

	/* Clear logs from corrected errors in case there's no user-level logger */
	rh = (sal_log_record_header_t *)buffer;
	if (rh->severity == sal_log_severity_corrected)
		ia64_sal_clear_state_info(sal_info_type);
}

/*
 * platform dependent error handling
 */
#ifndef PLATFORM_MCA_HANDLERS

#ifdef CONFIG_ACPI

int cpe_vector = -1;

static irqreturn_t
ia64_mca_cpe_int_handler (int cpe_irq, void *arg, struct pt_regs *ptregs)
{
	static unsigned long	cpe_history[CPE_HISTORY_LENGTH];
	static int		index;
	static DEFINE_SPINLOCK(cpe_history_lock);

	IA64_MCA_DEBUG("%s: received interrupt vector = %#x on CPU %d\n",
		       __FUNCTION__, cpe_irq, smp_processor_id());

	/* SAL spec states this should run w/ interrupts enabled */
	local_irq_enable();

	/* Get the CPE error record and log it */
	ia64_mca_log_sal_error_record(SAL_INFO_TYPE_CPE);

	spin_lock(&cpe_history_lock);
	if (!cpe_poll_enabled && cpe_vector >= 0) {

		int i, count = 1; /* we know 1 happened now */
		unsigned long now = jiffies;

		for (i = 0; i < CPE_HISTORY_LENGTH; i++) {
			if (now - cpe_history[i] <= HZ)
				count++;
		}

		IA64_MCA_DEBUG(KERN_INFO "CPE threshold %d/%d\n", count, CPE_HISTORY_LENGTH);
		if (count >= CPE_HISTORY_LENGTH) {

			cpe_poll_enabled = 1;
			spin_unlock(&cpe_history_lock);
			disable_irq_nosync(local_vector_to_irq(IA64_CPE_VECTOR));

			/*
			 * Corrected errors will still be corrected, but
			 * make sure there's a log somewhere that indicates
			 * something is generating more than we can handle.
			 */
			printk(KERN_WARNING "WARNING: Switching to polling CPE handler; error records may be lost\n");

			mod_timer(&cpe_poll_timer, jiffies + MIN_CPE_POLL_INTERVAL);

			/* lock already released, get out now */
			return IRQ_HANDLED;
		} else {
			cpe_history[index++] = now;
			if (index == CPE_HISTORY_LENGTH)
				index = 0;
		}
	}
	spin_unlock(&cpe_history_lock);
	return IRQ_HANDLED;
}

#endif /* CONFIG_ACPI */

#ifdef CONFIG_ACPI
/*
 * ia64_mca_register_cpev
 *
 *  Register the corrected platform error vector with SAL.
 *
 *  Inputs
 *      cpev        Corrected Platform Error Vector number
 *
 *  Outputs
 *      None
 */
static void
ia64_mca_register_cpev (int cpev)
{
	/* Register the CPE interrupt vector with SAL */
	struct ia64_sal_retval isrv;

	isrv = ia64_sal_mc_set_params(SAL_MC_PARAM_CPE_INT, SAL_MC_PARAM_MECHANISM_INT, cpev, 0, 0);
	if (isrv.status) {
		printk(KERN_ERR "Failed to register Corrected Platform "
		       "Error interrupt vector with SAL (status %ld)\n", isrv.status);
		return;
	}

	IA64_MCA_DEBUG("%s: corrected platform error "
		       "vector %#x registered\n", __FUNCTION__, cpev);
}
#endif /* CONFIG_ACPI */

#endif /* PLATFORM_MCA_HANDLERS */

/*
 * ia64_mca_cmc_vector_setup
 *
 *  Setup the corrected machine check vector register in the processor.
 *  (The interrupt is masked on boot. ia64_mca_late_init unmask this.)
 *  This function is invoked on a per-processor basis.
 *
 * Inputs
 *      None
 *
 * Outputs
 *	None
 */
void
ia64_mca_cmc_vector_setup (void)
{
	cmcv_reg_t	cmcv;

	cmcv.cmcv_regval	= 0;
	cmcv.cmcv_mask		= 1;        /* Mask/disable interrupt at first */
	cmcv.cmcv_vector	= IA64_CMC_VECTOR;
	ia64_setreg(_IA64_REG_CR_CMCV, cmcv.cmcv_regval);

	IA64_MCA_DEBUG("%s: CPU %d corrected "
		       "machine check vector %#x registered.\n",
		       __FUNCTION__, smp_processor_id(), IA64_CMC_VECTOR);

	IA64_MCA_DEBUG("%s: CPU %d CMCV = %#016lx\n",
		       __FUNCTION__, smp_processor_id(), ia64_getreg(_IA64_REG_CR_CMCV));
}

/*
 * ia64_mca_cmc_vector_disable
 *
 *  Mask the corrected machine check vector register in the processor.
 *  This function is invoked on a per-processor basis.
 *
 * Inputs
 *      dummy(unused)
 *
 * Outputs
 *	None
 */
static void
ia64_mca_cmc_vector_disable (void *dummy)
{
	cmcv_reg_t	cmcv;

	cmcv.cmcv_regval = ia64_getreg(_IA64_REG_CR_CMCV);