Merge branch 'clkfwk'

[linux-2.6/libata-dev.git] / drivers / edac / edac_pci.c

/*
 * EDAC PCI component
 *
 * Author: Dave Jiang <djiang@mvista.com>
 *
 * 2007 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 *
 */
#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/spinlock.h>
#include <linux/list.h>
#include <linux/sysdev.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"

static DEFINE_MUTEX(edac_pci_ctls_mutex);
static struct list_head edac_pci_list = LIST_HEAD_INIT(edac_pci_list);

static inline void edac_lock_pci_list(void)
{
        mutex_lock(&edac_pci_ctls_mutex);
}

static inline void edac_unlock_pci_list(void)
{
        mutex_unlock(&edac_pci_ctls_mutex);
}

/*
 * The alloc() and free() functions for the 'edac_pci' control info
 * structure. The chip driver will allocate one of these for each
 * edac_pci it is going to control/register with the EDAC CORE.
 */
struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
                                                const char *edac_pci_name)
{
        struct edac_pci_ctl_info *pci;
        void *pvt;
        unsigned int size;

        pci = (struct edac_pci_ctl_info *)0;
        pvt = edac_align_ptr(&pci[1], sz_pvt);
        size = ((unsigned long)pvt) + sz_pvt;

        if ((pci = kzalloc(size, GFP_KERNEL)) == NULL)
                return NULL;

        pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;

        pci->pvt_info = pvt;

        pci->op_state = OP_ALLOC;

        snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);

        return pci;
}

EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);

/*
 * edac_pci_free_ctl_info()
 *      frees the memory allocated by edac_pci_alloc_ctl_info() function
 */
void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
{
        kfree(pci);
}

EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);

/*
 * find_edac_pci_by_dev()
 *      scans the edac_pci list for a specific 'struct device *'
 */
static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
{
        struct edac_pci_ctl_info *pci;
        struct list_head *item;

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

        list_for_each(item, &edac_pci_list) {
                pci = list_entry(item, struct edac_pci_ctl_info, link);

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

        return NULL;
}

/*
 * add_edac_pci_to_global_list
 *      Before calling this function, caller must assign a unique value to
 *      edac_dev->pci_idx.
 *      Return:
 *              0 on success
 *              1 on failure
 */
static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
{
        struct list_head *item, *insert_before;
        struct edac_pci_ctl_info *rover;

        insert_before = &edac_pci_list;

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

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

                if (rover->pci_idx >= pci->pci_idx) {
                        if (unlikely(rover->pci_idx == pci->pci_idx))
                                goto fail1;

                        insert_before = item;
                        break;
                }
        }

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

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

fail1:
        edac_printk(KERN_WARNING, EDAC_PCI,
                "but in low-level driver: attempt to assign\n"
                "\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
                __func__);
        return 1;
}

/*
 * complete_edac_pci_list_del
 */
static void complete_edac_pci_list_del(struct rcu_head *head)
{
        struct edac_pci_ctl_info *pci;

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

/*
 * del_edac_pci_from_global_list
 */
static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
{
        list_del_rcu(&pci->link);
        init_completion(&pci->complete);
        call_rcu(&pci->rcu, complete_edac_pci_list_del);
        wait_for_completion(&pci->complete);
}

/*
 * edac_pci_find()
 *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 *
 * If found, return a pointer to the structure
 * Else return NULL.
 *
 * Caller must hold pci_ctls_mutex.
 */
struct edac_pci_ctl_info *edac_pci_find(int idx)
{
        struct list_head *item;
        struct edac_pci_ctl_info *pci;

        /* Iterage over list, looking for exact match of ID */
        list_for_each(item, &edac_pci_list) {
                pci = list_entry(item, struct edac_pci_ctl_info, link);

                if (pci->pci_idx >= idx) {
                        if (pci->pci_idx == idx)
                                return pci;

                        /* not on list, so terminate early */
                        break;
                }
        }

        return NULL;
}

EXPORT_SYMBOL_GPL(edac_pci_find);

/*
 * edac_pci_workq_function()
 *      performs the operation scheduled by a workq request
 */
static void edac_pci_workq_function(struct work_struct *work_req)
{
        struct delayed_work *d_work = (struct delayed_work *)work_req;
        struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);

        edac_lock_pci_list();

        if ((pci->op_state == OP_RUNNING_POLL) &&
                (pci->edac_check != NULL) && (edac_pci_get_check_errors()))
                pci->edac_check(pci);

        edac_unlock_pci_list();

        /* Reschedule */
        queue_delayed_work(edac_workqueue, &pci->work,
                        msecs_to_jiffies(edac_pci_get_poll_msec()));
}

/*
 * edac_pci_workq_setup()
 *      initialize a workq item for this edac_pci instance
 *      passing in the new delay period in msec
 */
static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
                                 unsigned int msec)
{
        debugf0("%s()\n", __func__);

        INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
        queue_delayed_work(edac_workqueue, &pci->work,
                        msecs_to_jiffies(edac_pci_get_poll_msec()));
}

/*
 * edac_pci_workq_teardown()
 *      stop the workq processing on this edac_pci instance
 */
static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
{
        int status;

        status = cancel_delayed_work(&pci->work);
        if (status == 0)
                flush_workqueue(edac_workqueue);
}

/*
 * edac_pci_reset_delay_period
 */
void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
                                 unsigned long value)
{
        edac_lock_pci_list();

        edac_pci_workq_teardown(pci);

        edac_pci_workq_setup(pci, value);

        edac_unlock_pci_list();
}

EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);

/*
 * edac_pci_add_device: Insert the 'edac_dev' structure into the
 * edac_pci global list and create sysfs entries associated with
 * edac_pci structure.
 * @pci: pointer to the edac_device structure to be added to the list
 * @edac_idx: A unique numeric identifier to be assigned to the
 * 'edac_pci' structure.
 *
 * Return:
 *      0       Success
 *      !0      Failure
 */
int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
{
        debugf0("%s()\n", __func__);

        pci->pci_idx = edac_idx;

        edac_lock_pci_list();

        if (add_edac_pci_to_global_list(pci))
                goto fail0;

        pci->start_time = jiffies;

        if (edac_pci_create_sysfs(pci)) {
                edac_pci_printk(pci, KERN_WARNING,
                                "failed to create sysfs pci\n");
                goto fail1;
        }

        if (pci->edac_check != NULL) {
                pci->op_state = OP_RUNNING_POLL;

                edac_pci_workq_setup(pci, 1000);
        } else {
                pci->op_state = OP_RUNNING_INTERRUPT;
        }

        edac_pci_printk(pci, KERN_INFO,
                        "Giving out device to module '%s' controller '%s':"
                        " DEV '%s' (%s)\n",
                        pci->mod_name,
                        pci->ctl_name,
                        dev_name(pci), edac_op_state_to_string(pci->op_state));

        edac_unlock_pci_list();
        return 0;

fail1:
        del_edac_pci_from_global_list(pci);
fail0:
        edac_unlock_pci_list();
        return 1;
}

EXPORT_SYMBOL_GPL(edac_pci_add_device);

/*
 * edac_pci_del_device()
 *      Remove sysfs entries for specified edac_pci structure and
 *      then remove edac_pci structure from global list
 *
 * @dev:
 *      Pointer to 'struct device' representing edac_pci structure
 *      to remove
 *
 * Return:
 *      Pointer to removed edac_pci structure,
 *      or NULL if device not found
 */
struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
{
        struct edac_pci_ctl_info *pci;

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

        edac_lock_pci_list();

        if ((pci = find_edac_pci_by_dev(dev)) == NULL) {
                edac_unlock_pci_list();
                return NULL;
        }

        pci->op_state = OP_OFFLINE;

        edac_pci_workq_teardown(pci);

        edac_pci_remove_sysfs(pci);

        del_edac_pci_from_global_list(pci);

        edac_unlock_pci_list();

        edac_printk(KERN_INFO, EDAC_PCI,
                "Removed device %d for %s %s: DEV %s\n",
                pci->pci_idx, pci->mod_name, pci->ctl_name, dev_name(pci));

        return pci;
}

EXPORT_SYMBOL_GPL(edac_pci_del_device);

void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
{
        edac_pci_do_parity_check();
}

static int edac_pci_idx;
#define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"

struct edac_pci_gen_data {
        int edac_idx;
};

struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
                                                const char *mod_name)
{
        struct edac_pci_ctl_info *pci;
        struct edac_pci_gen_data *pdata;

        pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
        if (!pci)
                return NULL;

        pdata = pci->pvt_info;
        pci->dev = dev;
        dev_set_drvdata(pci->dev, pci);
        pci->dev_name = pci_name(to_pci_dev(dev));

        pci->mod_name = mod_name;
        pci->ctl_name = EDAC_PCI_GENCTL_NAME;
        pci->edac_check = edac_pci_generic_check;

        pdata->edac_idx = edac_pci_idx++;

        if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
                debugf3("%s(): failed edac_pci_add_device()\n", __func__);
                edac_pci_free_ctl_info(pci);
                return NULL;
        }

        return pci;
}

EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);

void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
{
        edac_pci_del_device(pci->dev);
        edac_pci_free_ctl_info(pci);
}

EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);