drivers/edac: mod assert_error check

[deliverable/linux.git] / drivers / edac / edac_mc.c

/*
 * edac_mc kernel module
 * (C) 2005, 2006 Linux Networx (http://lnxi.com)
 * This file may be distributed under the terms of the
 * GNU General Public License.
 *
 * Written by Thayne Harbaugh
 * Based on work by Dan Hollis <goemon at anime dot net> and others.
 *      http://www.anime.net/~goemon/linux-ecc/
 *
 * Modified by Dave Peterson and Doug Thompson
 *
 */

#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/sysdev.h>
#include <linux/ctype.h>
#include <linux/edac.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/edac.h>
#include "edac_core.h"
#include "edac_module.h"


/* lock to memory controller's control array */
static DEFINE_MUTEX(mem_ctls_mutex);
static struct list_head mc_devices = LIST_HEAD_INIT(mc_devices);

#ifdef CONFIG_EDAC_DEBUG

static void edac_mc_dump_channel(struct channel_info *chan)
{
        debugf4("\tchannel = %p\n", chan);
        debugf4("\tchannel->chan_idx = %d\n", chan->chan_idx);
        debugf4("\tchannel->ce_count = %d\n", chan->ce_count);
        debugf4("\tchannel->label = '%s'\n", chan->label);
        debugf4("\tchannel->csrow = %p\n\n", chan->csrow);
}

static void edac_mc_dump_csrow(struct csrow_info *csrow)
{
        debugf4("\tcsrow = %p\n", csrow);
        debugf4("\tcsrow->csrow_idx = %d\n", csrow->csrow_idx);
        debugf4("\tcsrow->first_page = 0x%lx\n",
                csrow->first_page);
        debugf4("\tcsrow->last_page = 0x%lx\n", csrow->last_page);
        debugf4("\tcsrow->page_mask = 0x%lx\n", csrow->page_mask);
        debugf4("\tcsrow->nr_pages = 0x%x\n", csrow->nr_pages);
        debugf4("\tcsrow->nr_channels = %d\n",
                csrow->nr_channels);
        debugf4("\tcsrow->channels = %p\n", csrow->channels);
        debugf4("\tcsrow->mci = %p\n\n", csrow->mci);
}

static void edac_mc_dump_mci(struct mem_ctl_info *mci)
{
        debugf3("\tmci = %p\n", mci);
        debugf3("\tmci->mtype_cap = %lx\n", mci->mtype_cap);
        debugf3("\tmci->edac_ctl_cap = %lx\n", mci->edac_ctl_cap);
        debugf3("\tmci->edac_cap = %lx\n", mci->edac_cap);
        debugf4("\tmci->edac_check = %p\n", mci->edac_check);
        debugf3("\tmci->nr_csrows = %d, csrows = %p\n",
                mci->nr_csrows, mci->csrows);
        debugf3("\tdev = %p\n", mci->dev);
        debugf3("\tmod_name:ctl_name = %s:%s\n",
                mci->mod_name, mci->ctl_name);
        debugf3("\tpvt_info = %p\n\n", mci->pvt_info);
}

#endif  /* CONFIG_EDAC_DEBUG */

/* 'ptr' points to a possibly unaligned item X such that sizeof(X) is 'size'.
 * Adjust 'ptr' so that its alignment is at least as stringent as what the
 * compiler would provide for X and return the aligned result.
 *
 * If 'size' is a constant, the compiler will optimize this whole function
 * down to either a no-op or the addition of a constant to the value of 'ptr'.
 */
char * edac_align_ptr(void *ptr, unsigned size)
{
        unsigned align, r;

        /* Here we assume that the alignment of a "long long" is the most
         * stringent alignment that the compiler will ever provide by default.
         * As far as I know, this is a reasonable assumption.
         */
        if (size > sizeof(long))
                align = sizeof(long long);
        else if (size > sizeof(int))
                align = sizeof(long);
        else if (size > sizeof(short))
                align = sizeof(int);
        else if (size > sizeof(char))
                align = sizeof(short);
        else
                return (char *) ptr;

        r = size % align;

        if (r == 0)
                return (char *) ptr;

        return (char *) (((unsigned long) ptr) + align - r);
}

/**
 * edac_mc_alloc: Allocate a struct mem_ctl_info structure
 * @size_pvt:   size of private storage needed
 * @nr_csrows:  Number of CWROWS needed for this MC
 * @nr_chans:   Number of channels for the MC
 *
 * Everything is kmalloc'ed as one big chunk - more efficient.
 * Only can be used if all structures have the same lifetime - otherwise
 * you have to allocate and initialize your own structures.
 *
 * Use edac_mc_free() to free mc structures allocated by this function.
 *
 * Returns:
 *      NULL allocation failed
 *      struct mem_ctl_info pointer
 */
struct mem_ctl_info *edac_mc_alloc(unsigned sz_pvt, unsigned nr_csrows,
                unsigned nr_chans)
{
        struct mem_ctl_info *mci;
        struct csrow_info *csi, *csrow;
        struct channel_info *chi, *chp, *chan;
        void *pvt;
        unsigned size;
        int row, chn;

        /* Figure out the offsets of the various items from the start of an mc
         * structure.  We want the alignment of each item to be at least as
         * stringent as what the compiler would provide if we could simply
         * hardcode everything into a single struct.
         */
        mci = (struct mem_ctl_info *) 0;
        csi = (struct csrow_info *)edac_align_ptr(&mci[1], sizeof(*csi));
        chi = (struct channel_info *)
                        edac_align_ptr(&csi[nr_csrows], sizeof(*chi));
        pvt = edac_align_ptr(&chi[nr_chans * nr_csrows], sz_pvt);
        size = ((unsigned long) pvt) + sz_pvt;

        if ((mci = kmalloc(size, GFP_KERNEL)) == NULL)
                return NULL;

        /* Adjust pointers so they point within the memory we just allocated
         * rather than an imaginary chunk of memory located at address 0.
         */
        csi = (struct csrow_info *) (((char *) mci) + ((unsigned long) csi));
        chi = (struct channel_info *) (((char *) mci) + ((unsigned long) chi));
        pvt = sz_pvt ? (((char *) mci) + ((unsigned long) pvt)) : NULL;

        memset(mci, 0, size);  /* clear all fields */
        mci->csrows = csi;
        mci->pvt_info = pvt;
        mci->nr_csrows = nr_csrows;

        for (row = 0; row < nr_csrows; row++) {
                csrow = &csi[row];
                csrow->csrow_idx = row;
                csrow->mci = mci;
                csrow->nr_channels = nr_chans;
                chp = &chi[row * nr_chans];
                csrow->channels = chp;

                for (chn = 0; chn < nr_chans; chn++) {
                        chan = &chp[chn];
                        chan->chan_idx = chn;
                        chan->csrow = csrow;
                }
        }

        mci->op_state = OP_ALLOC;

        return mci;
}
EXPORT_SYMBOL_GPL(edac_mc_alloc);

/**
 * edac_mc_free:  Free a previously allocated 'mci' structure
 * @mci: pointer to a struct mem_ctl_info structure
 */
void edac_mc_free(struct mem_ctl_info *mci)
{
        kfree(mci);
}
EXPORT_SYMBOL_GPL(edac_mc_free);

static struct mem_ctl_info *find_mci_by_dev(struct device *dev)
{
        struct mem_ctl_info *mci;
        struct list_head *item;

        debugf3("%s()\n", __func__);

        list_for_each(item, &mc_devices) {
                mci = list_entry(item, struct mem_ctl_info, link);

                if (mci->dev == dev)
                        return mci;
        }

        return NULL;
}

/*
 * handler for EDAC to check if NMI type handler has asserted interrupt
 */
static int edac_mc_assert_error_check_and_clear(void)
{
        int old_state;

        if(edac_op_state == EDAC_OPSTATE_POLL)
                return 1;

        old_state = edac_err_assert;
        edac_err_assert = 0;

        return old_state;
}

/*
 * edac_mc_workq_function
 *      performs the operation scheduled by a workq request
 */
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20))
static void edac_mc_workq_function(struct work_struct *work_req)
{
        struct delayed_work *d_work = (struct delayed_work*) work_req;
        struct mem_ctl_info *mci = to_edac_mem_ctl_work(d_work);
#else
static void edac_mc_workq_function(void *ptr)
{
        struct mem_ctl_info *mci = (struct mem_ctl_info *) ptr;
#endif

        mutex_lock(&mem_ctls_mutex);

        /* Only poll controllers that are running polled and have a check */
        if (edac_mc_assert_error_check_and_clear() && (mci->edac_check != NULL))
                mci->edac_check(mci);

        /*
         * FIXME: temp place holder for PCI checks,
         * goes away when we break out PCI
         */
        edac_pci_do_parity_check();

        mutex_unlock(&mem_ctls_mutex);

        /* Reschedule */
        queue_delayed_work(edac_workqueue, &mci->work, edac_mc_get_poll_msec());
}

/*
 * edac_mc_workq_setup
 *      initialize a workq item for this mci
 *      passing in the new delay period in msec
 */
void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
{
        debugf0("%s()\n", __func__);

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20))
        INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
#else
        INIT_WORK(&mci->work, edac_mc_workq_function, mci);
#endif
        queue_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
}

/*
 * edac_mc_workq_teardown
 *      stop the workq processing on this mci
 */
void edac_mc_workq_teardown(struct mem_ctl_info *mci)
{
        int status;

        status = cancel_delayed_work(&mci->work);
        if (status == 0) {
                /* workq instance might be running, wait for it */
                flush_workqueue(edac_workqueue);
        }
}

/*
 * edac_reset_delay_period
 */

void edac_reset_delay_period(struct mem_ctl_info *mci, unsigned long value)
{
        mutex_lock(&mem_ctls_mutex);

        /* cancel the current workq request */
        edac_mc_workq_teardown(mci);

        /* restart the workq request, with new delay value */
        edac_mc_workq_setup(mci, value);

        mutex_unlock(&mem_ctls_mutex);
}

/* Return 0 on success, 1 on failure.
 * Before calling this function, caller must
 * assign a unique value to mci->mc_idx.
 */
static int add_mc_to_global_list (struct mem_ctl_info *mci)
{
        struct list_head *item, *insert_before;
        struct mem_ctl_info *p;

        insert_before = &mc_devices;

        if (unlikely((p = find_mci_by_dev(mci->dev)) != NULL))
                goto fail0;

        list_for_each(item, &mc_devices) {
                p = list_entry(item, struct mem_ctl_info, link);

                if (p->mc_idx >= mci->mc_idx) {
                        if (unlikely(p->mc_idx == mci->mc_idx))
                                goto fail1;

                        insert_before = item;
                        break;
                }
        }

        list_add_tail_rcu(&mci->link, insert_before);
        atomic_inc(&edac_handlers);
        return 0;

fail0:
        edac_printk(KERN_WARNING, EDAC_MC,
                    "%s (%s) %s %s already assigned %d\n", p->dev->bus_id,
                    dev_name(mci), p->mod_name, p->ctl_name, p->mc_idx);
        return 1;

fail1:
        edac_printk(KERN_WARNING, EDAC_MC,
                    "bug in low-level driver: attempt to assign\n"
                    "    duplicate mc_idx %d in %s()\n", p->mc_idx, __func__);
        return 1;
}

static void complete_mc_list_del(struct rcu_head *head)
{
        struct mem_ctl_info *mci;

        mci = container_of(head, struct mem_ctl_info, rcu);
        INIT_LIST_HEAD(&mci->link);
        complete(&mci->complete);
}

static void del_mc_from_global_list(struct mem_ctl_info *mci)
{
        atomic_dec(&edac_handlers);
        list_del_rcu(&mci->link);
        init_completion(&mci->complete);
        call_rcu(&mci->rcu, complete_mc_list_del);
        wait_for_completion(&mci->complete);
}

/**
 * edac_mc_find: Search for a mem_ctl_info structure whose index is 'idx'.
 *
 * If found, return a pointer to the structure.
 * Else return NULL.
 *
 * Caller must hold mem_ctls_mutex.
 */
struct mem_ctl_info * edac_mc_find(int idx)
{
        struct list_head *item;
        struct mem_ctl_info *mci;

        list_for_each(item, &mc_devices) {
                mci = list_entry(item, struct mem_ctl_info, link);

                if (mci->mc_idx >= idx) {
                        if (mci->mc_idx == idx)
                                return mci;

                        break;
                }
        }

        return NULL;
}
EXPORT_SYMBOL(edac_mc_find);

/**
 * edac_mc_add_mc: Insert the 'mci' structure into the mci global list and
 *                 create sysfs entries associated with mci structure
 * @mci: pointer to the mci structure to be added to the list
 * @mc_idx: A unique numeric identifier to be assigned to the 'mci' structure.
 *
 * Return:
 *      0       Success
 *      !0      Failure
 */

/* FIXME - should a warning be printed if no error detection? correction? */
int edac_mc_add_mc(struct mem_ctl_info *mci, int mc_idx)
{
        debugf0("%s()\n", __func__);
        mci->mc_idx = mc_idx;
#ifdef CONFIG_EDAC_DEBUG
        if (edac_debug_level >= 3)
                edac_mc_dump_mci(mci);

        if (edac_debug_level >= 4) {
                int i;

                for (i = 0; i < mci->nr_csrows; i++) {
                        int j;

                        edac_mc_dump_csrow(&mci->csrows[i]);
                        for (j = 0; j < mci->csrows[i].nr_channels; j++)
                                edac_mc_dump_channel(
                                        &mci->csrows[i].channels[j]);
                }
        }
#endif
        mutex_lock(&mem_ctls_mutex);

        if (add_mc_to_global_list(mci))
                goto fail0;

        /* set load time so that error rate can be tracked */
        mci->start_time = jiffies;

        if (edac_create_sysfs_mci_device(mci)) {
                edac_mc_printk(mci, KERN_WARNING,
                        "failed to create sysfs device\n");
                goto fail1;
        }

        /* If there IS a check routine, then we are running POLLED */
        if (mci->edac_check != NULL) {
                /* This instance is NOW RUNNING */
                mci->op_state = OP_RUNNING_POLL;

                edac_mc_workq_setup(mci, edac_mc_get_poll_msec());
        } else {
                mci->op_state = OP_RUNNING_INTERRUPT;
        }

        /* Report action taken */
        edac_mc_printk(mci, KERN_INFO, "Giving out device to %s %s: DEV %s\n",
                mci->mod_name, mci->ctl_name, dev_name(mci));

        mutex_unlock(&mem_ctls_mutex);
        return 0;

fail1:
        del_mc_from_global_list(mci);

fail0:
        mutex_unlock(&mem_ctls_mutex);
        return 1;
}
EXPORT_SYMBOL_GPL(edac_mc_add_mc);

/**
 * edac_mc_del_mc: Remove sysfs entries for specified mci structure and
 *                 remove mci structure from global list
 * @pdev: Pointer to 'struct device' representing mci structure to remove.
 *
 * Return pointer to removed mci structure, or NULL if device not found.
 */
struct mem_ctl_info * edac_mc_del_mc(struct device *dev)
{
        struct mem_ctl_info *mci;

        debugf0("MC: %s()\n", __func__);
        mutex_lock(&mem_ctls_mutex);

        if ((mci = find_mci_by_dev(dev)) == NULL) {
                mutex_unlock(&mem_ctls_mutex);
                return NULL;
        }

        /* marking MCI offline */
        mci->op_state = OP_OFFLINE;

        /* flush workq processes */
        edac_mc_workq_teardown(mci);

        edac_remove_sysfs_mci_device(mci);
        del_mc_from_global_list(mci);
        mutex_unlock(&mem_ctls_mutex);
        edac_printk(KERN_INFO, EDAC_MC,
                "Removed device %d for %s %s: DEV %s\n", mci->mc_idx,
                mci->mod_name, mci->ctl_name, dev_name(mci));
        return mci;
}
EXPORT_SYMBOL_GPL(edac_mc_del_mc);

static void edac_mc_scrub_block(unsigned long page, unsigned long offset,
                                u32 size)
{
        struct page *pg;
        void *virt_addr;
        unsigned long flags = 0;

        debugf3("%s()\n", __func__);

        /* ECC error page was not in our memory. Ignore it. */
        if(!pfn_valid(page))
                return;

        /* Find the actual page structure then map it and fix */
        pg = pfn_to_page(page);

        if (PageHighMem(pg))
                local_irq_save(flags);

        virt_addr = kmap_atomic(pg, KM_BOUNCE_READ);

        /* Perform architecture specific atomic scrub operation */
        atomic_scrub(virt_addr + offset, size);

        /* Unmap and complete */
        kunmap_atomic(virt_addr, KM_BOUNCE_READ);

        if (PageHighMem(pg))
                local_irq_restore(flags);
}

/* FIXME - should return -1 */
int edac_mc_find_csrow_by_page(struct mem_ctl_info *mci, unsigned long page)
{
        struct csrow_info *csrows = mci->csrows;
        int row, i;

        debugf1("MC%d: %s(): 0x%lx\n", mci->mc_idx, __func__, page);
        row = -1;

        for (i = 0; i < mci->nr_csrows; i++) {
                struct csrow_info *csrow = &csrows[i];

                if (csrow->nr_pages == 0)
                        continue;

                debugf3("MC%d: %s(): first(0x%lx) page(0x%lx) last(0x%lx) "
                        "mask(0x%lx)\n", mci->mc_idx, __func__,
                        csrow->first_page, page, csrow->last_page,
                        csrow->page_mask);

                if ((page >= csrow->first_page) &&
                    (page <= csrow->last_page) &&
                    ((page & csrow->page_mask) ==
                     (csrow->first_page & csrow->page_mask))) {
                        row = i;
                        break;
                }
        }

        if (row == -1)
                edac_mc_printk(mci, KERN_ERR,
                        "could not look up page error address %lx\n",
                        (unsigned long) page);

        return row;
}
EXPORT_SYMBOL_GPL(edac_mc_find_csrow_by_page);

/* FIXME - setable log (warning/emerg) levels */
/* FIXME - integrate with evlog: http://evlog.sourceforge.net/ */
void edac_mc_handle_ce(struct mem_ctl_info *mci,
                unsigned long page_frame_number, unsigned long offset_in_page,
                unsigned long syndrome, int row, int channel, const char *msg)
{
        unsigned long remapped_page;

        debugf3("MC%d: %s()\n", mci->mc_idx, __func__);

        /* FIXME - maybe make panic on INTERNAL ERROR an option */
        if (row >= mci->nr_csrows || row < 0) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: row out of range "
                        "(%d >= %d)\n", row, mci->nr_csrows);
                edac_mc_handle_ce_no_info(mci, "INTERNAL ERROR");
                return;
        }

        if (channel >= mci->csrows[row].nr_channels || channel < 0) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: channel out of range "
                        "(%d >= %d)\n", channel,
                        mci->csrows[row].nr_channels);
                edac_mc_handle_ce_no_info(mci, "INTERNAL ERROR");
                return;
        }

        if (edac_get_log_ce())
                /* FIXME - put in DIMM location */
                edac_mc_printk(mci, KERN_WARNING,
                        "CE page 0x%lx, offset 0x%lx, grain %d, syndrome "
                        "0x%lx, row %d, channel %d, label \"%s\": %s\n",
                        page_frame_number, offset_in_page,
                        mci->csrows[row].grain, syndrome, row, channel,
                        mci->csrows[row].channels[channel].label, msg);

        mci->ce_count++;
        mci->csrows[row].ce_count++;
        mci->csrows[row].channels[channel].ce_count++;

        if (mci->scrub_mode & SCRUB_SW_SRC) {
                /*
                 * Some MC's can remap memory so that it is still available
                 * at a different address when PCI devices map into memory.
                 * MC's that can't do this lose the memory where PCI devices
                 * are mapped.  This mapping is MC dependant and so we call
                 * back into the MC driver for it to map the MC page to
                 * a physical (CPU) page which can then be mapped to a virtual
                 * page - which can then be scrubbed.
                 */
                remapped_page = mci->ctl_page_to_phys ?
                    mci->ctl_page_to_phys(mci, page_frame_number) :
                    page_frame_number;

                edac_mc_scrub_block(remapped_page, offset_in_page,
                                        mci->csrows[row].grain);
        }
}
EXPORT_SYMBOL_GPL(edac_mc_handle_ce);

void edac_mc_handle_ce_no_info(struct mem_ctl_info *mci, const char *msg)
{
        if (edac_get_log_ce())
                edac_mc_printk(mci, KERN_WARNING,
                        "CE - no information available: %s\n", msg);

        mci->ce_noinfo_count++;
        mci->ce_count++;
}
EXPORT_SYMBOL_GPL(edac_mc_handle_ce_no_info);

void edac_mc_handle_ue(struct mem_ctl_info *mci,
                unsigned long page_frame_number, unsigned long offset_in_page,
                int row, const char *msg)
{
        int len = EDAC_MC_LABEL_LEN * 4;
        char labels[len + 1];
        char *pos = labels;
        int chan;
        int chars;

        debugf3("MC%d: %s()\n", mci->mc_idx, __func__);

        /* FIXME - maybe make panic on INTERNAL ERROR an option */
        if (row >= mci->nr_csrows || row < 0) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: row out of range "
                        "(%d >= %d)\n", row, mci->nr_csrows);
                edac_mc_handle_ue_no_info(mci, "INTERNAL ERROR");
                return;
        }

        chars = snprintf(pos, len + 1, "%s",
                        mci->csrows[row].channels[0].label);
        len -= chars;
        pos += chars;

        for (chan = 1; (chan < mci->csrows[row].nr_channels) && (len > 0);
             chan++) {
                chars = snprintf(pos, len + 1, ":%s",
                                mci->csrows[row].channels[chan].label);
                len -= chars;
                pos += chars;
        }

        if (edac_get_log_ue())
                edac_mc_printk(mci, KERN_EMERG,
                        "UE page 0x%lx, offset 0x%lx, grain %d, row %d, "
                        "labels \"%s\": %s\n", page_frame_number,
                        offset_in_page, mci->csrows[row].grain, row, labels,
                        msg);

        if (edac_get_panic_on_ue())
                panic("EDAC MC%d: UE page 0x%lx, offset 0x%lx, grain %d, "
                        "row %d, labels \"%s\": %s\n", mci->mc_idx,
                        page_frame_number, offset_in_page,
                        mci->csrows[row].grain, row, labels, msg);

        mci->ue_count++;
        mci->csrows[row].ue_count++;
}
EXPORT_SYMBOL_GPL(edac_mc_handle_ue);

void edac_mc_handle_ue_no_info(struct mem_ctl_info *mci, const char *msg)
{
        if (edac_get_panic_on_ue())
                panic("EDAC MC%d: Uncorrected Error", mci->mc_idx);

        if (edac_get_log_ue())
                edac_mc_printk(mci, KERN_WARNING,
                        "UE - no information available: %s\n", msg);
        mci->ue_noinfo_count++;
        mci->ue_count++;
}
EXPORT_SYMBOL_GPL(edac_mc_handle_ue_no_info);


/*************************************************************
 * On Fully Buffered DIMM modules, this help function is
 * called to process UE events
 */
void edac_mc_handle_fbd_ue(struct mem_ctl_info *mci,
                                unsigned int csrow,
                                unsigned int channela,
                                unsigned int channelb,
                                char *msg)
{
        int len = EDAC_MC_LABEL_LEN * 4;
        char labels[len + 1];
        char *pos = labels;
        int chars;

        if (csrow >= mci->nr_csrows) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: row out of range (%d >= %d)\n",
                        csrow, mci->nr_csrows);
                edac_mc_handle_ue_no_info(mci, "INTERNAL ERROR");
                return;
        }

        if (channela >= mci->csrows[csrow].nr_channels) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: channel-a out of range "
                        "(%d >= %d)\n",
                        channela, mci->csrows[csrow].nr_channels);
                edac_mc_handle_ue_no_info(mci, "INTERNAL ERROR");
                return;
        }

        if (channelb >= mci->csrows[csrow].nr_channels) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: channel-b out of range "
                        "(%d >= %d)\n",
                        channelb, mci->csrows[csrow].nr_channels);
                edac_mc_handle_ue_no_info(mci, "INTERNAL ERROR");
                return;
        }

        mci->ue_count++;
        mci->csrows[csrow].ue_count++;

        /* Generate the DIMM labels from the specified channels */
        chars = snprintf(pos, len + 1, "%s",
                         mci->csrows[csrow].channels[channela].label);
        len -= chars; pos += chars;
        chars = snprintf(pos, len + 1, "-%s",
                         mci->csrows[csrow].channels[channelb].label);

        if (edac_get_log_ue())
                edac_mc_printk(mci, KERN_EMERG,
                        "UE row %d, channel-a= %d channel-b= %d "
                        "labels \"%s\": %s\n", csrow, channela, channelb,
                        labels, msg);

        if (edac_get_panic_on_ue())
                panic("UE row %d, channel-a= %d channel-b= %d "
                                "labels \"%s\": %s\n", csrow, channela,
                                channelb, labels, msg);
}
EXPORT_SYMBOL(edac_mc_handle_fbd_ue);

/*************************************************************
 * On Fully Buffered DIMM modules, this help function is
 * called to process CE events
 */
void edac_mc_handle_fbd_ce(struct mem_ctl_info *mci,
                           unsigned int csrow,
                           unsigned int channel,
                           char *msg)
{

        /* Ensure boundary values */
        if (csrow >= mci->nr_csrows) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: row out of range (%d >= %d)\n",
                        csrow, mci->nr_csrows);
                edac_mc_handle_ce_no_info(mci, "INTERNAL ERROR");
                return;
        }
        if (channel >= mci->csrows[csrow].nr_channels) {
                /* something is wrong */
                edac_mc_printk(mci, KERN_ERR,
                        "INTERNAL ERROR: channel out of range (%d >= %d)\n",
                        channel, mci->csrows[csrow].nr_channels);
                edac_mc_handle_ce_no_info(mci, "INTERNAL ERROR");
                return;
        }

        if (edac_get_log_ce())
                /* FIXME - put in DIMM location */
                edac_mc_printk(mci, KERN_WARNING,
                        "CE row %d, channel %d, label \"%s\": %s\n",
                        csrow, channel,
                        mci->csrows[csrow].channels[channel].label,
                        msg);

        mci->ce_count++;
        mci->csrows[csrow].ce_count++;
        mci->csrows[csrow].channels[channel].ce_count++;
}
EXPORT_SYMBOL(edac_mc_handle_fbd_ce);


/*
 * Iterate over all MC instances and check for ECC, et al, errors
 */
void edac_check_mc_devices(void)
{
        struct list_head *item;
        struct mem_ctl_info *mci;

        debugf3("%s()\n", __func__);
        mutex_lock(&mem_ctls_mutex);

        list_for_each(item, &mc_devices) {
                mci = list_entry(item, struct mem_ctl_info, link);

                if (mci->edac_check != NULL)
                        mci->edac_check(mci);
        }

        mutex_unlock(&mem_ctls_mutex);
}