mca_drv.c

linux 内核源代码

	 * 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;
	pal_min_state_area_t *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");