edac_device.c

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/*
 * edac_device.c
 * (C) 2007 www.douglaskthompson.com
 *
 * This file may be distributed under the terms of the
 * GNU General Public License.
 *
 * Written by Doug Thompson <[email protected]>
 *
 * edac_device API implementation
 * 19 Jan 2007
 */

#include <linux/module.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/ctype.h>
#include <linux/workqueue.h>
#include <asm/uaccess.h>
#include <asm/page.h>

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

/* lock for the list: 'edac_device_list', manipulation of this list
 * is protected by the 'device_ctls_mutex' lock
 */
static DEFINE_MUTEX(device_ctls_mutex);
static LIST_HEAD(edac_device_list);

#ifdef CONFIG_EDAC_DEBUG
static void edac_device_dump_device(struct edac_device_ctl_info *edac_dev)
{
    edac_dbg(3, "\tedac_dev = %p dev_idx=%d\n",
         edac_dev, edac_dev->dev_idx);
    edac_dbg(4, "\tedac_dev->edac_check = %p\n", edac_dev->edac_check);
    edac_dbg(3, "\tdev = %p\n", edac_dev->dev);
    edac_dbg(3, "\tmod_name:ctl_name = %s:%s\n",
         edac_dev->mod_name, edac_dev->ctl_name);
    edac_dbg(3, "\tpvt_info = %p\n\n", edac_dev->pvt_info);
}
#endif              /* CONFIG_EDAC_DEBUG */


/*
 * edac_device_alloc_ctl_info()
 *  Allocate a new edac device control info structure
 *
 *  The control structure is allocated in complete chunk
 *  from the OS. It is in turn sub allocated to the
 *  various objects that compose the structure
 *
 *  The structure has a 'nr_instance' array within itself.
 *  Each instance represents a major component
 *      Example:  L1 cache and L2 cache are 2 instance components
 *
 *  Within each instance is an array of 'nr_blocks' blockoffsets
 */
struct edac_device_ctl_info *edac_device_alloc_ctl_info(
    unsigned sz_private,
    char *edac_device_name, unsigned nr_instances,
    char *edac_block_name, unsigned nr_blocks,
    unsigned offset_value,      /* zero, 1, or other based offset */
    struct edac_dev_sysfs_block_attribute *attrib_spec, unsigned nr_attrib,
    int device_index)
{
    struct edac_device_ctl_info *dev_ctl;
    struct edac_device_instance *dev_inst, *inst;
    struct edac_device_block *dev_blk, *blk_p, *blk;
    struct edac_dev_sysfs_block_attribute *dev_attrib, *attrib_p, *attrib;
    unsigned total_size;
    unsigned count;
    unsigned instance, block, attr;
    void *pvt, *p;
    int err;

    edac_dbg(4, "instances=%d blocks=%d\n", nr_instances, nr_blocks);

    /* Calculate the size of memory we need to allocate AND
     * determine the offsets of the various item arrays
     * (instance,block,attrib) from the start of an  allocated structure.
     * We want the alignment of each item  (instance,block,attrib)
     * to be at least as stringent as what the compiler would
     * provide if we could simply hardcode everything into a single struct.
     */
    p = NULL;
    dev_ctl = edac_align_ptr(&p, sizeof(*dev_ctl), 1);

    /* Calc the 'end' offset past end of ONE ctl_info structure
     * which will become the start of the 'instance' array
     */
    dev_inst = edac_align_ptr(&p, sizeof(*dev_inst), nr_instances);

    /* Calc the 'end' offset past the instance array within the ctl_info
     * which will become the start of the block array
     */
    count = nr_instances * nr_blocks;
    dev_blk = edac_align_ptr(&p, sizeof(*dev_blk), count);

    /* Calc the 'end' offset past the dev_blk array
     * which will become the start of the attrib array, if any.
     */
    /* calc how many nr_attrib we need */
    if (nr_attrib > 0)
        count *= nr_attrib;
    dev_attrib = edac_align_ptr(&p, sizeof(*dev_attrib), count);

    /* Calc the 'end' offset past the attributes array */
    pvt = edac_align_ptr(&p, sz_private, 1);

    /* 'pvt' now points to where the private data area is.
     * At this point 'pvt' (like dev_inst,dev_blk and dev_attrib)
     * is baselined at ZERO
     */
    total_size = ((unsigned long)pvt) + sz_private;

    /* Allocate the amount of memory for the set of control structures */
    dev_ctl = kzalloc(total_size, GFP_KERNEL);
    if (dev_ctl == NULL)
        return NULL;

    /* Adjust pointers so they point within the actual memory we
     * just allocated rather than an imaginary chunk of memory
     * located at address 0.
     * 'dev_ctl' points to REAL memory, while the others are
     * ZERO based and thus need to be adjusted to point within
     * the allocated memory.
     */
    dev_inst = (struct edac_device_instance *)
        (((char *)dev_ctl) + ((unsigned long)dev_inst));
    dev_blk = (struct edac_device_block *)
        (((char *)dev_ctl) + ((unsigned long)dev_blk));
    dev_attrib = (struct edac_dev_sysfs_block_attribute *)
        (((char *)dev_ctl) + ((unsigned long)dev_attrib));
    pvt = sz_private ? (((char *)dev_ctl) + ((unsigned long)pvt)) : NULL;

    /* Begin storing the information into the control info structure */
    dev_ctl->dev_idx = device_index;
    dev_ctl->nr_instances = nr_instances;
    dev_ctl->instances = dev_inst;
    dev_ctl->pvt_info = pvt;

    /* Default logging of CEs and UEs */
    dev_ctl->log_ce = 1;
    dev_ctl->log_ue = 1;

    /* Name of this edac device */
    snprintf(dev_ctl->name,sizeof(dev_ctl->name),"%s",edac_device_name);

    edac_dbg(4, "edac_dev=%p next after end=%p\n",
         dev_ctl, pvt + sz_private);

    /* Initialize every Instance */
    for (instance = 0; instance < nr_instances; instance++) {
        inst = &dev_inst[instance];
        inst->ctl = dev_ctl;
        inst->nr_blocks = nr_blocks;
        blk_p = &dev_blk[instance * nr_blocks];
        inst->blocks = blk_p;

        /* name of this instance */
        snprintf(inst->name, sizeof(inst->name),
             "%s%u", edac_device_name, instance);

        /* Initialize every block in each instance */
        for (block = 0; block < nr_blocks; block++) {
            blk = &blk_p[block];
            blk->instance = inst;
            snprintf(blk->name, sizeof(blk->name),
                 "%s%d", edac_block_name, block+offset_value);

            edac_dbg(4, "instance=%d inst_p=%p block=#%d block_p=%p name='%s'\n",
                 instance, inst, block, blk, blk->name);

            /* if there are NO attributes OR no attribute pointer
             * then continue on to next block iteration
             */
            if ((nr_attrib == 0) || (attrib_spec == NULL))
                continue;

            /* setup the attribute array for this block */
            blk->nr_attribs = nr_attrib;
            attrib_p = &dev_attrib[block*nr_instances*nr_attrib];
            blk->block_attributes = attrib_p;

            edac_dbg(4, "THIS BLOCK_ATTRIB=%p\n",
                 blk->block_attributes);

            /* Initialize every user specified attribute in this
             * block with the data the caller passed in
             * Each block gets its own copy of pointers,
             * and its unique 'value'
             */
            for (attr = 0; attr < nr_attrib; attr++) {
                attrib = &attrib_p[attr];

                /* populate the unique per attrib
                 * with the code pointers and info
                 */
                attrib->attr = attrib_spec[attr].attr;
                attrib->show = attrib_spec[attr].show;
                attrib->store = attrib_spec[attr].store;

                attrib->block = blk;    /* up link */

                edac_dbg(4, "alloc-attrib=%p attrib_name='%s' attrib-spec=%p spec-name=%s\n",
                     attrib, attrib->attr.name,
                     &attrib_spec[attr],
                     attrib_spec[attr].attr.name
                    );
            }
        }
    }

    /* Mark this instance as merely ALLOCATED */
    dev_ctl->op_state = OP_ALLOC;

    /*
     * Initialize the 'root' kobj for the edac_device controller
     */
    err = edac_device_register_sysfs_main_kobj(dev_ctl);
    if (err) {
        kfree(dev_ctl);
        return NULL;
    }

    /* at this point, the root kobj is valid, and in order to
     * 'free' the object, then the function:
     *  edac_device_unregister_sysfs_main_kobj() must be called
     * which will perform kobj unregistration and the actual free
     * will occur during the kobject callback operation
     */

    return dev_ctl;
}
EXPORT_SYMBOL_GPL(edac_device_alloc_ctl_info);

/*
 * edac_device_free_ctl_info()
 *  frees the memory allocated by the edac_device_alloc_ctl_info()
 *  function
 */
void edac_device_free_ctl_info(struct edac_device_ctl_info *ctl_info)
{
    edac_device_unregister_sysfs_main_kobj(ctl_info);
}
EXPORT_SYMBOL_GPL(edac_device_free_ctl_info);

/*
 * find_edac_device_by_dev
 *  scans the edac_device list for a specific 'struct device *'
 *
 *  lock to be held prior to call:  device_ctls_mutex
 *
 *  Return:
 *      pointer to control structure managing 'dev'
 *      NULL if not found on list
 */
static struct edac_device_ctl_info *find_edac_device_by_dev(struct device *dev)
{
    struct edac_device_ctl_info *edac_dev;
    struct list_head *item;

    edac_dbg(0, "\n");

    list_for_each(item, &edac_device_list) {
        edac_dev = list_entry(item, struct edac_device_ctl_info, link);

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

    return NULL;
}

/*
 * add_edac_dev_to_global_list
 *  Before calling this function, caller must
 *  assign a unique value to edac_dev->dev_idx.
 *
 *  lock to be held prior to call:  device_ctls_mutex
 *
 *  Return:
 *      0 on success
 *      1 on failure.
 */
static int add_edac_dev_to_global_list(struct edac_device_ctl_info *edac_dev)
{
    struct list_head *item, *insert_before;
    struct edac_device_ctl_info *rover;

    insert_before = &edac_device_list;

    /* Determine if already on the list */
    rover = find_edac_device_by_dev(edac_dev->dev);
    if (unlikely(rover != NULL))
        goto fail0;

    /* Insert in ascending order by 'dev_idx', so find position */
    list_for_each(item, &edac_device_list) {
        rover = list_entry(item, struct edac_device_ctl_info, link);

        if (rover->dev_idx >= edac_dev->dev_idx) {
            if (unlikely(rover->dev_idx == edac_dev->dev_idx))
                goto fail1;

            insert_before = item;
            break;
        }
    }

    list_add_tail_rcu(&edac_dev->link, insert_before);
    return 0;

fail0:
    edac_printk(KERN_WARNING, EDAC_MC,
            "%s (%s) %s %s already assigned %d\n",
            dev_name(rover->dev), edac_dev_name(rover),
            rover->mod_name, rover->ctl_name, rover->dev_idx);
    return 1;

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

/*
 * del_edac_device_from_global_list
 */
static void del_edac_device_from_global_list(struct edac_device_ctl_info
                        *edac_device)
{
    list_del_rcu(&edac_device->link);

    /* these are for safe removal of devices from global list while
     * NMI handlers may be traversing list
     */
    synchronize_rcu();
    INIT_LIST_HEAD(&edac_device->link);
}

/*
 * edac_device_workq_function
 *  performs the operation scheduled by a workq request
 *
 *  this workq is embedded within an edac_device_ctl_info
 *  structure, that needs to be polled for possible error events.
 *
 *  This operation is to acquire the list mutex lock
 *  (thus preventing insertation or deletion)
 *  and then call the device's poll function IFF this device is
 *  running polled and there is a poll function defined.
 */
static void edac_device_workq_function(struct work_struct *work_req)
{
    struct delayed_work *d_work = to_delayed_work(work_req);
    struct edac_device_ctl_info *edac_dev = to_edac_device_ctl_work(d_work);

    mutex_lock(&device_ctls_mutex);

    /* If we are being removed, bail out immediately */
    if (edac_dev->op_state == OP_OFFLINE) {
        mutex_unlock(&device_ctls_mutex);
        return;
    }

    /* Only poll controllers that are running polled and have a check */
    if ((edac_dev->op_state == OP_RUNNING_POLL) &&
        (edac_dev->edac_check != NULL)) {
            edac_dev->edac_check(edac_dev);
    }

    mutex_unlock(&device_ctls_mutex);

    /* Reschedule the workq for the next time period to start again
     * if the number of msec is for 1 sec, then adjust to the next
     * whole one second to save timers firing all over the period
     * between integral seconds
     */
    if (edac_dev->poll_msec == 1000)
        queue_delayed_work(edac_workqueue, &edac_dev->work,
                round_jiffies_relative(edac_dev->delay));
    else
        queue_delayed_work(edac_workqueue, &edac_dev->work,
                edac_dev->delay);
}

/*
 * edac_device_workq_setup
 *  initialize a workq item for this edac_device instance
 *  passing in the new delay period in msec
 */
void edac_device_workq_setup(struct edac_device_ctl_info *edac_dev,
                unsigned msec)
{
    edac_dbg(0, "\n");

    /* take the arg 'msec' and set it into the control structure
     * to used in the time period calculation
     * then calc the number of jiffies that represents
     */
    edac_dev->poll_msec = msec;
    edac_dev->delay = msecs_to_jiffies(msec);

    INIT_DELAYED_WORK(&edac_dev->work, edac_device_workq_function);

    /* optimize here for the 1 second case, which will be normal value, to
     * fire ON the 1 second time event. This helps reduce all sorts of
     * timers firing on sub-second basis, while they are happy
     * to fire together on the 1 second exactly
     */
    if (edac_dev->poll_msec == 1000)
        queue_delayed_work(edac_workqueue, &edac_dev->work,
                round_jiffies_relative(edac_dev->delay));
    else
        queue_delayed_work(edac_workqueue, &edac_dev->work,
                edac_dev->delay);
}

/*
 * edac_device_workq_teardown
 *  stop the workq processing on this edac_dev
 */
void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)
{
    int status;

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

/*
 * edac_device_reset_delay_period
 *
 *  need to stop any outstanding workq queued up at this time
 *  because we will be resetting the sleep time.
 *  Then restart the workq on the new delay
 */
void edac_device_reset_delay_period(struct edac_device_ctl_info *edac_dev,
                    unsigned long value)
{
    /* cancel the current workq request, without the mutex lock */
    edac_device_workq_teardown(edac_dev);

    /* acquire the mutex before doing the workq setup */
    mutex_lock(&device_ctls_mutex);

    /* restart the workq request, with new delay value */
    edac_device_workq_setup(edac_dev, value);

    mutex_unlock(&device_ctls_mutex);
}

/*
 * edac_device_alloc_index: Allocate a unique device index number
 *
 * Return:
 *  allocated index number
 */
int edac_device_alloc_index(void)
{
    static atomic_t device_indexes = ATOMIC_INIT(0);

    return atomic_inc_return(&device_indexes) - 1;
}
EXPORT_SYMBOL_GPL(edac_device_alloc_index);

int edac_device_add_device(struct edac_device_ctl_info *edac_dev)
{
    edac_dbg(0, "\n");

#ifdef CONFIG_EDAC_DEBUG
    if (edac_debug_level >= 3)
        edac_device_dump_device(edac_dev);
#endif
    mutex_lock(&device_ctls_mutex);

    if (add_edac_dev_to_global_list(edac_dev))
        goto fail0;

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

    /* create this instance's sysfs entries */
    if (edac_device_create_sysfs(edac_dev)) {
        edac_device_printk(edac_dev, KERN_WARNING,
                    "failed to create sysfs device\n");
        goto fail1;
    }

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

        /*
         * enable workq processing on this instance,
         * default = 1000 msec
         */
        edac_device_workq_setup(edac_dev, 1000);
    } else {
        edac_dev->op_state = OP_RUNNING_INTERRUPT;
    }

    /* Report action taken */
    edac_device_printk(edac_dev, KERN_INFO,
                "Giving out device to module '%s' controller "
                "'%s': DEV '%s' (%s)\n",
                edac_dev->mod_name,
                edac_dev->ctl_name,
                edac_dev_name(edac_dev),
                edac_op_state_to_string(edac_dev->op_state));

    mutex_unlock(&device_ctls_mutex);
    return 0;

fail1:
    /* Some error, so remove the entry from the lsit */
    del_edac_device_from_global_list(edac_dev);

fail0:
    mutex_unlock(&device_ctls_mutex);
    return 1;
}
EXPORT_SYMBOL_GPL(edac_device_add_device);

struct edac_device_ctl_info *edac_device_del_device(struct device *dev)
{
    struct edac_device_ctl_info *edac_dev;

    edac_dbg(0, "\n");

    mutex_lock(&device_ctls_mutex);

    /* Find the structure on the list, if not there, then leave */
    edac_dev = find_edac_device_by_dev(dev);
    if (edac_dev == NULL) {
        mutex_unlock(&device_ctls_mutex);
        return NULL;
    }

    /* mark this instance as OFFLINE */
    edac_dev->op_state = OP_OFFLINE;

    /* deregister from global list */
    del_edac_device_from_global_list(edac_dev);

    mutex_unlock(&device_ctls_mutex);

    /* clear workq processing on this instance */
    edac_device_workq_teardown(edac_dev);

    /* Tear down the sysfs entries for this instance */
    edac_device_remove_sysfs(edac_dev);

    edac_printk(KERN_INFO, EDAC_MC,
        "Removed device %d for %s %s: DEV %s\n",
        edac_dev->dev_idx,
        edac_dev->mod_name, edac_dev->ctl_name, edac_dev_name(edac_dev));

    return edac_dev;
}
EXPORT_SYMBOL_GPL(edac_device_del_device);

static inline int edac_device_get_log_ce(struct edac_device_ctl_info *edac_dev)
{
    return edac_dev->log_ce;
}

static inline int edac_device_get_log_ue(struct edac_device_ctl_info *edac_dev)
{
    return edac_dev->log_ue;
}

static inline int edac_device_get_panic_on_ue(struct edac_device_ctl_info
                    *edac_dev)
{
    return edac_dev->panic_on_ue;
}

/*
 * edac_device_handle_ce
 *  perform a common output and handling of an 'edac_dev' CE event
 */
void edac_device_handle_ce(struct edac_device_ctl_info *edac_dev,
            int inst_nr, int block_nr, const char *msg)
{
    struct edac_device_instance *instance;
    struct edac_device_block *block = NULL;

    if ((inst_nr >= edac_dev->nr_instances) || (inst_nr < 0)) {
        edac_device_printk(edac_dev, KERN_ERR,
                "INTERNAL ERROR: 'instance' out of range "
                "(%d >= %d)\n", inst_nr,
                edac_dev->nr_instances);
        return;
    }

    instance = edac_dev->instances + inst_nr;

    if ((block_nr >= instance->nr_blocks) || (block_nr < 0)) {
        edac_device_printk(edac_dev, KERN_ERR,
                "INTERNAL ERROR: instance %d 'block' "
                "out of range (%d >= %d)\n",
                inst_nr, block_nr,
                instance->nr_blocks);
        return;
    }

    if (instance->nr_blocks > 0) {
        block = instance->blocks + block_nr;
        block->counters.ce_count++;
    }

    /* Propagate the count up the 'totals' tree */
    instance->counters.ce_count++;
    edac_dev->counters.ce_count++;

    if (edac_device_get_log_ce(edac_dev))
        edac_device_printk(edac_dev, KERN_WARNING,
                "CE: %s instance: %s block: %s '%s'\n",
                edac_dev->ctl_name, instance->name,
                block ? block->name : "N/A", msg);
}
EXPORT_SYMBOL_GPL(edac_device_handle_ce);

/*
 * edac_device_handle_ue
 *  perform a common output and handling of an 'edac_dev' UE event
 */
void edac_device_handle_ue(struct edac_device_ctl_info *edac_dev,
            int inst_nr, int block_nr, const char *msg)
{
    struct edac_device_instance *instance;
    struct edac_device_block *block = NULL;

    if ((inst_nr >= edac_dev->nr_instances) || (inst_nr < 0)) {
        edac_device_printk(edac_dev, KERN_ERR,
                "INTERNAL ERROR: 'instance' out of range "
                "(%d >= %d)\n", inst_nr,
                edac_dev->nr_instances);
        return;
    }

    instance = edac_dev->instances + inst_nr;

    if ((block_nr >= instance->nr_blocks) || (block_nr < 0)) {
        edac_device_printk(edac_dev, KERN_ERR,
                "INTERNAL ERROR: instance %d 'block' "
                "out of range (%d >= %d)\n",
                inst_nr, block_nr,
                instance->nr_blocks);
        return;
    }

    if (instance->nr_blocks > 0) {
        block = instance->blocks + block_nr;
        block->counters.ue_count++;
    }

    /* Propagate the count up the 'totals' tree */
    instance->counters.ue_count++;
    edac_dev->counters.ue_count++;

    if (edac_device_get_log_ue(edac_dev))
        edac_device_printk(edac_dev, KERN_EMERG,
                "UE: %s instance: %s block: %s '%s'\n",
                edac_dev->ctl_name, instance->name,
                block ? block->name : "N/A", msg);

    if (edac_device_get_panic_on_ue(edac_dev))
        panic("EDAC %s: UE instance: %s block %s '%s'\n",
            edac_dev->ctl_name, instance->name,
            block ? block->name : "N/A", msg);
}
EXPORT_SYMBOL_GPL(edac_device_handle_ue);