driver-core: fix devtmpfs crash on s390

[linux-2.6/linux-2.6-openrd.git] / drivers / edac / edac_mc_sysfs.c

/*
 * edac_mc kernel module
 * (C) 2005-2007 Linux Networx (http://lnxi.com)
 *
 * This file may be distributed under the terms of the
 * GNU General Public License.
 *
 * Written Doug Thompson <norsk5@xmission.com> www.softwarebitmaker.com
 *
 */

#include <linux/ctype.h>
#include <linux/bug.h>

#include "edac_core.h"
#include "edac_module.h"


/* MC EDAC Controls, setable by module parameter, and sysfs */
static int edac_mc_log_ue = 1;
static int edac_mc_log_ce = 1;
static int edac_mc_panic_on_ue;
static int edac_mc_poll_msec = 1000;

/* Getter functions for above */
int edac_mc_get_log_ue(void)
{
        return edac_mc_log_ue;
}

int edac_mc_get_log_ce(void)
{
        return edac_mc_log_ce;
}

int edac_mc_get_panic_on_ue(void)
{
        return edac_mc_panic_on_ue;
}

/* this is temporary */
int edac_mc_get_poll_msec(void)
{
        return edac_mc_poll_msec;
}

static int edac_set_poll_msec(const char *val, struct kernel_param *kp)
{
        long l;
        int ret;

        if (!val)
                return -EINVAL;

        ret = strict_strtol(val, 0, &l);
        if (ret == -EINVAL || ((int)l != l))
                return -EINVAL;
        *((int *)kp->arg) = l;

        /* notify edac_mc engine to reset the poll period */
        edac_mc_reset_delay_period(l);

        return 0;
}

/* Parameter declarations for above */
module_param(edac_mc_panic_on_ue, int, 0644);
MODULE_PARM_DESC(edac_mc_panic_on_ue, "Panic on uncorrected error: 0=off 1=on");
module_param(edac_mc_log_ue, int, 0644);
MODULE_PARM_DESC(edac_mc_log_ue,
                 "Log uncorrectable error to console: 0=off 1=on");
module_param(edac_mc_log_ce, int, 0644);
MODULE_PARM_DESC(edac_mc_log_ce,
                 "Log correctable error to console: 0=off 1=on");
module_param_call(edac_mc_poll_msec, edac_set_poll_msec, param_get_int,
                  &edac_mc_poll_msec, 0644);
MODULE_PARM_DESC(edac_mc_poll_msec, "Polling period in milliseconds");

/*
 * various constants for Memory Controllers
 */
static const char *mem_types[] = {
        [MEM_EMPTY] = "Empty",
        [MEM_RESERVED] = "Reserved",
        [MEM_UNKNOWN] = "Unknown",
        [MEM_FPM] = "FPM",
        [MEM_EDO] = "EDO",
        [MEM_BEDO] = "BEDO",
        [MEM_SDR] = "Unbuffered-SDR",
        [MEM_RDR] = "Registered-SDR",
        [MEM_DDR] = "Unbuffered-DDR",
        [MEM_RDDR] = "Registered-DDR",
        [MEM_RMBS] = "RMBS",
        [MEM_DDR2] = "Unbuffered-DDR2",
        [MEM_FB_DDR2] = "FullyBuffered-DDR2",
        [MEM_RDDR2] = "Registered-DDR2",
        [MEM_XDR] = "XDR",
        [MEM_DDR3] = "Unbuffered-DDR3",
        [MEM_RDDR3] = "Registered-DDR3"
};

static const char *dev_types[] = {
        [DEV_UNKNOWN] = "Unknown",
        [DEV_X1] = "x1",
        [DEV_X2] = "x2",
        [DEV_X4] = "x4",
        [DEV_X8] = "x8",
        [DEV_X16] = "x16",
        [DEV_X32] = "x32",
        [DEV_X64] = "x64"
};

static const char *edac_caps[] = {
        [EDAC_UNKNOWN] = "Unknown",
        [EDAC_NONE] = "None",
        [EDAC_RESERVED] = "Reserved",
        [EDAC_PARITY] = "PARITY",
        [EDAC_EC] = "EC",
        [EDAC_SECDED] = "SECDED",
        [EDAC_S2ECD2ED] = "S2ECD2ED",
        [EDAC_S4ECD4ED] = "S4ECD4ED",
        [EDAC_S8ECD8ED] = "S8ECD8ED",
        [EDAC_S16ECD16ED] = "S16ECD16ED"
};



static ssize_t memctrl_int_store(void *ptr, const char *buffer, size_t count)
{
        int *value = (int *)ptr;

        if (isdigit(*buffer))
                *value = simple_strtoul(buffer, NULL, 0);

        return count;
}


/* EDAC sysfs CSROW data structures and methods
 */

/* Set of more default csrow<id> attribute show/store functions */
static ssize_t csrow_ue_count_show(struct csrow_info *csrow, char *data,
                                int private)
{
        return sprintf(data, "%u\n", csrow->ue_count);
}

static ssize_t csrow_ce_count_show(struct csrow_info *csrow, char *data,
                                int private)
{
        return sprintf(data, "%u\n", csrow->ce_count);
}

static ssize_t csrow_size_show(struct csrow_info *csrow, char *data,
                                int private)
{
        return sprintf(data, "%u\n", PAGES_TO_MiB(csrow->nr_pages));
}

static ssize_t csrow_mem_type_show(struct csrow_info *csrow, char *data,
                                int private)
{
        return sprintf(data, "%s\n", mem_types[csrow->mtype]);
}

static ssize_t csrow_dev_type_show(struct csrow_info *csrow, char *data,
                                int private)
{
        return sprintf(data, "%s\n", dev_types[csrow->dtype]);
}

static ssize_t csrow_edac_mode_show(struct csrow_info *csrow, char *data,
                                int private)
{
        return sprintf(data, "%s\n", edac_caps[csrow->edac_mode]);
}

/* show/store functions for DIMM Label attributes */
static ssize_t channel_dimm_label_show(struct csrow_info *csrow,
                                char *data, int channel)
{
        /* if field has not been initialized, there is nothing to send */
        if (!csrow->channels[channel].label[0])
                return 0;

        return snprintf(data, EDAC_MC_LABEL_LEN, "%s\n",
                        csrow->channels[channel].label);
}

static ssize_t channel_dimm_label_store(struct csrow_info *csrow,
                                        const char *data,
                                        size_t count, int channel)
{
        ssize_t max_size = 0;

        max_size = min((ssize_t) count, (ssize_t) EDAC_MC_LABEL_LEN - 1);
        strncpy(csrow->channels[channel].label, data, max_size);
        csrow->channels[channel].label[max_size] = '\0';

        return max_size;
}

/* show function for dynamic chX_ce_count attribute */
static ssize_t channel_ce_count_show(struct csrow_info *csrow,
                                char *data, int channel)
{
        return sprintf(data, "%u\n", csrow->channels[channel].ce_count);
}

/* csrow specific attribute structure */
struct csrowdev_attribute {
        struct attribute attr;
         ssize_t(*show) (struct csrow_info *, char *, int);
         ssize_t(*store) (struct csrow_info *, const char *, size_t, int);
        int private;
};

#define to_csrow(k) container_of(k, struct csrow_info, kobj)
#define to_csrowdev_attr(a) container_of(a, struct csrowdev_attribute, attr)

/* Set of show/store higher level functions for default csrow attributes */
static ssize_t csrowdev_show(struct kobject *kobj,
                        struct attribute *attr, char *buffer)
{
        struct csrow_info *csrow = to_csrow(kobj);
        struct csrowdev_attribute *csrowdev_attr = to_csrowdev_attr(attr);

        if (csrowdev_attr->show)
                return csrowdev_attr->show(csrow,
                                        buffer, csrowdev_attr->private);
        return -EIO;
}

static ssize_t csrowdev_store(struct kobject *kobj, struct attribute *attr,
                        const char *buffer, size_t count)
{
        struct csrow_info *csrow = to_csrow(kobj);
        struct csrowdev_attribute *csrowdev_attr = to_csrowdev_attr(attr);

        if (csrowdev_attr->store)
                return csrowdev_attr->store(csrow,
                                        buffer,
                                        count, csrowdev_attr->private);
        return -EIO;
}

static struct sysfs_ops csrowfs_ops = {
        .show = csrowdev_show,
        .store = csrowdev_store
};

#define CSROWDEV_ATTR(_name,_mode,_show,_store,_private)        \
static struct csrowdev_attribute attr_##_name = {                       \
        .attr = {.name = __stringify(_name), .mode = _mode },   \
        .show   = _show,                                        \
        .store  = _store,                                       \
        .private = _private,                                    \
};

/* default cwrow<id>/attribute files */
CSROWDEV_ATTR(size_mb, S_IRUGO, csrow_size_show, NULL, 0);
CSROWDEV_ATTR(dev_type, S_IRUGO, csrow_dev_type_show, NULL, 0);
CSROWDEV_ATTR(mem_type, S_IRUGO, csrow_mem_type_show, NULL, 0);
CSROWDEV_ATTR(edac_mode, S_IRUGO, csrow_edac_mode_show, NULL, 0);
CSROWDEV_ATTR(ue_count, S_IRUGO, csrow_ue_count_show, NULL, 0);
CSROWDEV_ATTR(ce_count, S_IRUGO, csrow_ce_count_show, NULL, 0);

/* default attributes of the CSROW<id> object */
static struct csrowdev_attribute *default_csrow_attr[] = {
        &attr_dev_type,
        &attr_mem_type,
        &attr_edac_mode,
        &attr_size_mb,
        &attr_ue_count,
        &attr_ce_count,
        NULL,
};

/* possible dynamic channel DIMM Label attribute files */
CSROWDEV_ATTR(ch0_dimm_label, S_IRUGO | S_IWUSR,
        channel_dimm_label_show, channel_dimm_label_store, 0);
CSROWDEV_ATTR(ch1_dimm_label, S_IRUGO | S_IWUSR,
        channel_dimm_label_show, channel_dimm_label_store, 1);
CSROWDEV_ATTR(ch2_dimm_label, S_IRUGO | S_IWUSR,
        channel_dimm_label_show, channel_dimm_label_store, 2);
CSROWDEV_ATTR(ch3_dimm_label, S_IRUGO | S_IWUSR,
        channel_dimm_label_show, channel_dimm_label_store, 3);
CSROWDEV_ATTR(ch4_dimm_label, S_IRUGO | S_IWUSR,
        channel_dimm_label_show, channel_dimm_label_store, 4);
CSROWDEV_ATTR(ch5_dimm_label, S_IRUGO | S_IWUSR,
        channel_dimm_label_show, channel_dimm_label_store, 5);

/* Total possible dynamic DIMM Label attribute file table */
static struct csrowdev_attribute *dynamic_csrow_dimm_attr[] = {
        &attr_ch0_dimm_label,
        &attr_ch1_dimm_label,
        &attr_ch2_dimm_label,
        &attr_ch3_dimm_label,
        &attr_ch4_dimm_label,
        &attr_ch5_dimm_label
};

/* possible dynamic channel ce_count attribute files */
CSROWDEV_ATTR(ch0_ce_count, S_IRUGO | S_IWUSR, channel_ce_count_show, NULL, 0);
CSROWDEV_ATTR(ch1_ce_count, S_IRUGO | S_IWUSR, channel_ce_count_show, NULL, 1);
CSROWDEV_ATTR(ch2_ce_count, S_IRUGO | S_IWUSR, channel_ce_count_show, NULL, 2);
CSROWDEV_ATTR(ch3_ce_count, S_IRUGO | S_IWUSR, channel_ce_count_show, NULL, 3);
CSROWDEV_ATTR(ch4_ce_count, S_IRUGO | S_IWUSR, channel_ce_count_show, NULL, 4);
CSROWDEV_ATTR(ch5_ce_count, S_IRUGO | S_IWUSR, channel_ce_count_show, NULL, 5);

/* Total possible dynamic ce_count attribute file table */
static struct csrowdev_attribute *dynamic_csrow_ce_count_attr[] = {
        &attr_ch0_ce_count,
        &attr_ch1_ce_count,
        &attr_ch2_ce_count,
        &attr_ch3_ce_count,
        &attr_ch4_ce_count,
        &attr_ch5_ce_count
};

#define EDAC_NR_CHANNELS        6

/* Create dynamic CHANNEL files, indexed by 'chan',  under specifed CSROW */
static int edac_create_channel_files(struct kobject *kobj, int chan)
{
        int err = -ENODEV;

        if (chan >= EDAC_NR_CHANNELS)
                return err;

        /* create the DIMM label attribute file */
        err = sysfs_create_file(kobj,
                                (struct attribute *)
                                dynamic_csrow_dimm_attr[chan]);

        if (!err) {
                /* create the CE Count attribute file */
                err = sysfs_create_file(kobj,
                                        (struct attribute *)
                                        dynamic_csrow_ce_count_attr[chan]);
        } else {
                debugf1("%s()  dimm labels and ce_count files created",
                        __func__);
        }

        return err;
}

/* No memory to release for this kobj */
static void edac_csrow_instance_release(struct kobject *kobj)
{
        struct mem_ctl_info *mci;
        struct csrow_info *cs;

        debugf1("%s()\n", __func__);

        cs = container_of(kobj, struct csrow_info, kobj);
        mci = cs->mci;

        kobject_put(&mci->edac_mci_kobj);
}

/* the kobj_type instance for a CSROW */
static struct kobj_type ktype_csrow = {
        .release = edac_csrow_instance_release,
        .sysfs_ops = &csrowfs_ops,
        .default_attrs = (struct attribute **)default_csrow_attr,
};

/* Create a CSROW object under specifed edac_mc_device */
static int edac_create_csrow_object(struct mem_ctl_info *mci,
                                        struct csrow_info *csrow, int index)
{
        struct kobject *kobj_mci = &mci->edac_mci_kobj;
        struct kobject *kobj;
        int chan;
        int err;

        /* generate ..../edac/mc/mc<id>/csrow<index>   */
        memset(&csrow->kobj, 0, sizeof(csrow->kobj));
        csrow->mci = mci;       /* include container up link */

        /* bump the mci instance's kobject's ref count */
        kobj = kobject_get(&mci->edac_mci_kobj);
        if (!kobj) {
                err = -ENODEV;
                goto err_out;
        }

        /* Instanstiate the csrow object */
        err = kobject_init_and_add(&csrow->kobj, &ktype_csrow, kobj_mci,
                                   "csrow%d", index);
        if (err)
                goto err_release_top_kobj;

        /* At this point, to release a csrow kobj, one must
         * call the kobject_put and allow that tear down
         * to work the releasing
         */

        /* Create the dyanmic attribute files on this csrow,
         * namely, the DIMM labels and the channel ce_count
         */
        for (chan = 0; chan < csrow->nr_channels; chan++) {
                err = edac_create_channel_files(&csrow->kobj, chan);
                if (err) {
                        /* special case the unregister here */
                        kobject_put(&csrow->kobj);
                        goto err_out;
                }
        }
        kobject_uevent(&csrow->kobj, KOBJ_ADD);
        return 0;

        /* error unwind stack */
err_release_top_kobj:
        kobject_put(&mci->edac_mci_kobj);

err_out:
        return err;
}

/* default sysfs methods and data structures for the main MCI kobject */

static ssize_t mci_reset_counters_store(struct mem_ctl_info *mci,
                                        const char *data, size_t count)
{
        int row, chan;

        mci->ue_noinfo_count = 0;
        mci->ce_noinfo_count = 0;
        mci->ue_count = 0;
        mci->ce_count = 0;

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

                ri->ue_count = 0;
                ri->ce_count = 0;

                for (chan = 0; chan < ri->nr_channels; chan++)
                        ri->channels[chan].ce_count = 0;
        }

        mci->start_time = jiffies;
        return count;
}

/* memory scrubbing */
static ssize_t mci_sdram_scrub_rate_store(struct mem_ctl_info *mci,
                                        const char *data, size_t count)
{
        u32 bandwidth = -1;

        if (mci->set_sdram_scrub_rate) {

                memctrl_int_store(&bandwidth, data, count);

                if (!(*mci->set_sdram_scrub_rate) (mci, &bandwidth)) {
                        edac_printk(KERN_DEBUG, EDAC_MC,
                                "Scrub rate set successfully, applied: %d\n",
                                bandwidth);
                } else {
                        /* FIXME: error codes maybe? */
                        edac_printk(KERN_DEBUG, EDAC_MC,
                                "Scrub rate set FAILED, could not apply: %d\n",
                                bandwidth);
                }
        } else {
                /* FIXME: produce "not implemented" ERROR for user-side. */
                edac_printk(KERN_WARNING, EDAC_MC,
                        "Memory scrubbing 'set'control is not implemented!\n");
        }
        return count;
}

static ssize_t mci_sdram_scrub_rate_show(struct mem_ctl_info *mci, char *data)
{
        u32 bandwidth = -1;

        if (mci->get_sdram_scrub_rate) {
                if (!(*mci->get_sdram_scrub_rate) (mci, &bandwidth)) {
                        edac_printk(KERN_DEBUG, EDAC_MC,
                                "Scrub rate successfully, fetched: %d\n",
                                bandwidth);
                } else {
                        /* FIXME: error codes maybe? */
                        edac_printk(KERN_DEBUG, EDAC_MC,
                                "Scrub rate fetch FAILED, got: %d\n",
                                bandwidth);
                }
        } else {
                /* FIXME: produce "not implemented" ERROR for user-side.  */
                edac_printk(KERN_WARNING, EDAC_MC,
                        "Memory scrubbing 'get' control is not implemented\n");
        }
        return sprintf(data, "%d\n", bandwidth);
}

/* default attribute files for the MCI object */
static ssize_t mci_ue_count_show(struct mem_ctl_info *mci, char *data)
{
        return sprintf(data, "%d\n", mci->ue_count);
}

static ssize_t mci_ce_count_show(struct mem_ctl_info *mci, char *data)
{
        return sprintf(data, "%d\n", mci->ce_count);
}

static ssize_t mci_ce_noinfo_show(struct mem_ctl_info *mci, char *data)
{
        return sprintf(data, "%d\n", mci->ce_noinfo_count);
}

static ssize_t mci_ue_noinfo_show(struct mem_ctl_info *mci, char *data)
{
        return sprintf(data, "%d\n", mci->ue_noinfo_count);
}

static ssize_t mci_seconds_show(struct mem_ctl_info *mci, char *data)
{
        return sprintf(data, "%ld\n", (jiffies - mci->start_time) / HZ);
}

static ssize_t mci_ctl_name_show(struct mem_ctl_info *mci, char *data)
{
        return sprintf(data, "%s\n", mci->ctl_name);
}

static ssize_t mci_size_mb_show(struct mem_ctl_info *mci, char *data)
{
        int total_pages, csrow_idx;

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

                if (!csrow->nr_pages)
                        continue;

                total_pages += csrow->nr_pages;
        }

        return sprintf(data, "%u\n", PAGES_TO_MiB(total_pages));
}

#define to_mci(k) container_of(k, struct mem_ctl_info, edac_mci_kobj)
#define to_mcidev_attr(a) container_of(a,struct mcidev_sysfs_attribute,attr)

/* MCI show/store functions for top most object */
static ssize_t mcidev_show(struct kobject *kobj, struct attribute *attr,
                        char *buffer)
{
        struct mem_ctl_info *mem_ctl_info = to_mci(kobj);
        struct mcidev_sysfs_attribute *mcidev_attr = to_mcidev_attr(attr);

        if (mcidev_attr->show)
                return mcidev_attr->show(mem_ctl_info, buffer);

        return -EIO;
}

static ssize_t mcidev_store(struct kobject *kobj, struct attribute *attr,
                        const char *buffer, size_t count)
{
        struct mem_ctl_info *mem_ctl_info = to_mci(kobj);
        struct mcidev_sysfs_attribute *mcidev_attr = to_mcidev_attr(attr);

        if (mcidev_attr->store)
                return mcidev_attr->store(mem_ctl_info, buffer, count);

        return -EIO;
}

/* Intermediate show/store table */
static struct sysfs_ops mci_ops = {
        .show = mcidev_show,
        .store = mcidev_store
};

#define MCIDEV_ATTR(_name,_mode,_show,_store)                   \
static struct mcidev_sysfs_attribute mci_attr_##_name = {                       \
        .attr = {.name = __stringify(_name), .mode = _mode },   \
        .show   = _show,                                        \
        .store  = _store,                                       \
};

/* default Control file */
MCIDEV_ATTR(reset_counters, S_IWUSR, NULL, mci_reset_counters_store);

/* default Attribute files */
MCIDEV_ATTR(mc_name, S_IRUGO, mci_ctl_name_show, NULL);
MCIDEV_ATTR(size_mb, S_IRUGO, mci_size_mb_show, NULL);
MCIDEV_ATTR(seconds_since_reset, S_IRUGO, mci_seconds_show, NULL);
MCIDEV_ATTR(ue_noinfo_count, S_IRUGO, mci_ue_noinfo_show, NULL);
MCIDEV_ATTR(ce_noinfo_count, S_IRUGO, mci_ce_noinfo_show, NULL);
MCIDEV_ATTR(ue_count, S_IRUGO, mci_ue_count_show, NULL);
MCIDEV_ATTR(ce_count, S_IRUGO, mci_ce_count_show, NULL);

/* memory scrubber attribute file */
MCIDEV_ATTR(sdram_scrub_rate, S_IRUGO | S_IWUSR, mci_sdram_scrub_rate_show,
        mci_sdram_scrub_rate_store);

static struct mcidev_sysfs_attribute *mci_attr[] = {
        &mci_attr_reset_counters,
        &mci_attr_mc_name,
        &mci_attr_size_mb,
        &mci_attr_seconds_since_reset,
        &mci_attr_ue_noinfo_count,
        &mci_attr_ce_noinfo_count,
        &mci_attr_ue_count,
        &mci_attr_ce_count,
        &mci_attr_sdram_scrub_rate,
        NULL
};


/*
 * Release of a MC controlling instance
 *
 *      each MC control instance has the following resources upon entry:
 *              a) a ref count on the top memctl kobj
 *              b) a ref count on this module
 *
 *      this function must decrement those ref counts and then
 *      issue a free on the instance's memory
 */
static void edac_mci_control_release(struct kobject *kobj)
{
        struct mem_ctl_info *mci;

        mci = to_mci(kobj);

        debugf0("%s() mci instance idx=%d releasing\n", __func__, mci->mc_idx);

        /* decrement the module ref count */
        module_put(mci->owner);

        /* free the mci instance memory here */
        kfree(mci);
}

static struct kobj_type ktype_mci = {
        .release = edac_mci_control_release,
        .sysfs_ops = &mci_ops,
        .default_attrs = (struct attribute **)mci_attr,
};

/* EDAC memory controller sysfs kset:
 *      /sys/devices/system/edac/mc
 */
static struct kset *mc_kset;

/*
 * edac_mc_register_sysfs_main_kobj
 *
 *      setups and registers the main kobject for each mci
 */
int edac_mc_register_sysfs_main_kobj(struct mem_ctl_info *mci)
{
        struct kobject *kobj_mci;
        int err;

        debugf1("%s()\n", __func__);

        kobj_mci = &mci->edac_mci_kobj;

        /* Init the mci's kobject */
        memset(kobj_mci, 0, sizeof(*kobj_mci));

        /* Record which module 'owns' this control structure
         * and bump the ref count of the module
         */
        mci->owner = THIS_MODULE;

        /* bump ref count on this module */
        if (!try_module_get(mci->owner)) {
                err = -ENODEV;
                goto fail_out;
        }

        /* this instance become part of the mc_kset */
        kobj_mci->kset = mc_kset;

        /* register the mc<id> kobject to the mc_kset */
        err = kobject_init_and_add(kobj_mci, &ktype_mci, NULL,
                                   "mc%d", mci->mc_idx);
        if (err) {
                debugf1("%s()Failed to register '.../edac/mc%d'\n",
                        __func__, mci->mc_idx);
                goto kobj_reg_fail;
        }
        kobject_uevent(kobj_mci, KOBJ_ADD);

        /* At this point, to 'free' the control struct,
         * edac_mc_unregister_sysfs_main_kobj() must be used
         */

        debugf1("%s() Registered '.../edac/mc%d' kobject\n",
                __func__, mci->mc_idx);

        return 0;

        /* Error exit stack */

kobj_reg_fail:
        module_put(mci->owner);

fail_out:
        return err;
}

/*
 * edac_mc_register_sysfs_main_kobj
 *
 *      tears down and the main mci kobject from the mc_kset
 */
void edac_mc_unregister_sysfs_main_kobj(struct mem_ctl_info *mci)
{
        /* delete the kobj from the mc_kset */
        kobject_put(&mci->edac_mci_kobj);
}

#define EDAC_DEVICE_SYMLINK     "device"

/*
 * edac_create_mci_instance_attributes
 *      create MC driver specific attributes at the topmost level
 *      directory of this mci instance.
 */
static int edac_create_mci_instance_attributes(struct mem_ctl_info *mci)
{
        int err;
        struct mcidev_sysfs_attribute *sysfs_attrib;

        /* point to the start of the array and iterate over it
         * adding each attribute listed to this mci instance's kobject
         */
        sysfs_attrib = mci->mc_driver_sysfs_attributes;

        while (sysfs_attrib && sysfs_attrib->attr.name) {
                err = sysfs_create_file(&mci->edac_mci_kobj,
                                        (struct attribute*) sysfs_attrib);
                if (err) {
                        return err;
                }

                sysfs_attrib++;
        }

        return 0;
}

/*
 * edac_remove_mci_instance_attributes
 *      remove MC driver specific attributes at the topmost level
 *      directory of this mci instance.
 */
static void edac_remove_mci_instance_attributes(struct mem_ctl_info *mci)
{
        struct mcidev_sysfs_attribute *sysfs_attrib;

        /* point to the start of the array and iterate over it
         * adding each attribute listed to this mci instance's kobject
         */
        sysfs_attrib = mci->mc_driver_sysfs_attributes;

        /* loop if there are attributes and until we hit a NULL entry */
        while (sysfs_attrib && sysfs_attrib->attr.name) {
                sysfs_remove_file(&mci->edac_mci_kobj,
                                        (struct attribute *) sysfs_attrib);
                sysfs_attrib++;
        }
}


/*
 * Create a new Memory Controller kobject instance,
 *      mc<id> under the 'mc' directory
 *
 * Return:
 *      0       Success
 *      !0      Failure
 */
int edac_create_sysfs_mci_device(struct mem_ctl_info *mci)
{
        int i;
        int err;
        struct csrow_info *csrow;
        struct kobject *kobj_mci = &mci->edac_mci_kobj;

        debugf0("%s() idx=%d\n", __func__, mci->mc_idx);

        /* create a symlink for the device */
        err = sysfs_create_link(kobj_mci, &mci->dev->kobj,
                                EDAC_DEVICE_SYMLINK);
        if (err) {
                debugf1("%s() failure to create symlink\n", __func__);
                goto fail0;
        }

        /* If the low level driver desires some attributes,
         * then create them now for the driver.
         */
        if (mci->mc_driver_sysfs_attributes) {
                err = edac_create_mci_instance_attributes(mci);
                if (err) {
                        debugf1("%s() failure to create mci attributes\n",
                                __func__);
                        goto fail0;
                }
        }

        /* Make directories for each CSROW object under the mc<id> kobject
         */
        for (i = 0; i < mci->nr_csrows; i++) {
                csrow = &mci->csrows[i];

                /* Only expose populated CSROWs */
                if (csrow->nr_pages > 0) {
                        err = edac_create_csrow_object(mci, csrow, i);
                        if (err) {
                                debugf1("%s() failure: create csrow %d obj\n",
                                        __func__, i);
                                goto fail1;
                        }
                }
        }

        return 0;

        /* CSROW error: backout what has already been registered,  */
fail1:
        for (i--; i >= 0; i--) {
                if (csrow->nr_pages > 0) {
                        kobject_put(&mci->csrows[i].kobj);
                }
        }

        /* remove the mci instance's attributes, if any */
        edac_remove_mci_instance_attributes(mci);

        /* remove the symlink */
        sysfs_remove_link(kobj_mci, EDAC_DEVICE_SYMLINK);

fail0:
        return err;
}

/*
 * remove a Memory Controller instance
 */
void edac_remove_sysfs_mci_device(struct mem_ctl_info *mci)
{
        int i;

        debugf0("%s()\n", __func__);

        /* remove all csrow kobjects */
        for (i = 0; i < mci->nr_csrows; i++) {
                if (mci->csrows[i].nr_pages > 0) {
                        debugf0("%s()  unreg csrow-%d\n", __func__, i);
                        kobject_put(&mci->csrows[i].kobj);
                }
        }

        debugf0("%s()  remove_link\n", __func__);

        /* remove the symlink */
        sysfs_remove_link(&mci->edac_mci_kobj, EDAC_DEVICE_SYMLINK);

        debugf0("%s()  remove_mci_instance\n", __func__);

        /* remove this mci instance's attribtes */
        edac_remove_mci_instance_attributes(mci);

        debugf0("%s()  unregister this mci kobj\n", __func__);

        /* unregister this instance's kobject */
        kobject_put(&mci->edac_mci_kobj);
}




/*
 * edac_setup_sysfs_mc_kset(void)
 *
 * Initialize the mc_kset for the 'mc' entry
 *      This requires creating the top 'mc' directory with a kset
 *      and its controls/attributes.
 *
 *      To this 'mc' kset, instance 'mci' will be grouped as children.
 *
 * Return:  0 SUCCESS
 *         !0 FAILURE error code
 */
int edac_sysfs_setup_mc_kset(void)
{
        int err = 0;
        struct sysdev_class *edac_class;

        debugf1("%s()\n", __func__);

        /* get the /sys/devices/system/edac class reference */
        edac_class = edac_get_edac_class();
        if (edac_class == NULL) {
                debugf1("%s() no edac_class error=%d\n", __func__, err);
                goto fail_out;
        }

        /* Init the MC's kobject */
        mc_kset = kset_create_and_add("mc", NULL, &edac_class->kset.kobj);
        if (!mc_kset) {
                err = -ENOMEM;
                debugf1("%s() Failed to register '.../edac/mc'\n", __func__);
                goto fail_out;
        }

        debugf1("%s() Registered '.../edac/mc' kobject\n", __func__);

        return 0;


        /* error unwind stack */
fail_out:
        return err;
}

/*
 * edac_sysfs_teardown_mc_kset
 *
 *      deconstruct the mc_ket for memory controllers
 */
void edac_sysfs_teardown_mc_kset(void)
{
        kset_unregister(mc_kset);
}