/*
 * Defines, structures, APIs for edac_device
 *
 * (C) 2007 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/
 *
 * NMI handling support added by
 *     Dave Peterson <dsp@llnl.gov> <dave_peterson@pobox.com>
 *
 * Refactored for multi-source files:
 *      Doug Thompson <norsk5@xmission.com>
 *
 * Please look at Documentation/driver-api/edac.rst for more info about
 * EDAC core structs and functions.
 */

#ifndef _EDAC_DEVICE_H_
#define _EDAC_DEVICE_H_

#include <linux/completion.h>
#include <linux/device.h>
#include <linux/edac.h>
#include <linux/kobject.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/sysfs.h>
#include <linux/workqueue.h>


/*
 * The following are the structures to provide for a generic
 * or abstract 'edac_device'. This set of structures and the
 * code that implements the APIs for the same, provide for
 * registering EDAC type devices which are NOT standard memory.
 *
 * CPU caches (L1 and L2)
 * DMA engines
 * Core CPU switches
 * Fabric switch units
 * PCIe interface controllers
 * other EDAC/ECC type devices that can be monitored for
 * errors, etc.
 *
 * It allows for a 2 level set of hierarchy. For example:
 *
 * cache could be composed of L1, L2 and L3 levels of cache.
 * Each CPU core would have its own L1 cache, while sharing
 * L2 and maybe L3 caches.
 *
 * View them arranged, via the sysfs presentation:
 * /sys/devices/system/edac/..
 *
 *      mc/             <existing memory device directory>
 *      cpu/cpu0/..     <L1 and L2 block directory>
 *              /L1-cache/ce_count
 *                       /ue_count
 *              /L2-cache/ce_count
 *                       /ue_count
 *      cpu/cpu1/..     <L1 and L2 block directory>
 *              /L1-cache/ce_count
 *                       /ue_count
 *              /L2-cache/ce_count
 *                       /ue_count
 *      ...
 *
 *      the L1 and L2 directories would be "edac_device_block's"
 */

struct edac_device_counter {
        u32 ue_count;
        u32 ce_count;
};

/* forward reference */
struct edac_device_ctl_info;
struct edac_device_block;

/* edac_dev_sysfs_attribute structure
 *      used for driver sysfs attributes in mem_ctl_info
 *      for extra controls and attributes:
 *              like high level error Injection controls
 */
struct edac_dev_sysfs_attribute {
        struct attribute attr;
        ssize_t (*show)(struct edac_device_ctl_info *, char *);
        ssize_t (*store)(struct edac_device_ctl_info *, const char *, size_t);
};

/* edac_dev_sysfs_block_attribute structure
 *
 *      used in leaf 'block' nodes for adding controls/attributes
 *
 *      each block in each instance of the containing control structure
 *      can have an array of the following. The show and store functions
 *      will be filled in with the show/store function in the
 *      low level driver.
 *
 *      The 'value' field will be the actual value field used for
 *      counting
 */
struct edac_dev_sysfs_block_attribute {
        struct attribute attr;
        ssize_t (*show)(struct kobject *, struct attribute *, char *);
        ssize_t (*store)(struct kobject *, struct attribute *,
                        const char *, size_t);
        struct edac_device_block *block;

        unsigned int value;
};

/* device block control structure */
struct edac_device_block {
        struct edac_device_instance *instance;  /* Up Pointer */
        char name[EDAC_DEVICE_NAME_LEN + 1];

        struct edac_device_counter counters;    /* basic UE and CE counters */

        int nr_attribs;         /* how many attributes */

        /* this block's attributes, could be NULL */
        struct edac_dev_sysfs_block_attribute *block_attributes;

        /* edac sysfs device control */
        struct kobject kobj;
};

/* device instance control structure */
struct edac_device_instance {
        struct edac_device_ctl_info *ctl;       /* Up pointer */
        char name[EDAC_DEVICE_NAME_LEN + 4];

        struct edac_device_counter counters;    /* instance counters */

        u32 nr_blocks;          /* how many blocks */
        struct edac_device_block *blocks;       /* block array */

        /* edac sysfs device control */
        struct kobject kobj;
};


/*
 * Abstract edac_device control info structure
 *
 */
struct edac_device_ctl_info {
        /* for global list of edac_device_ctl_info structs */
        struct list_head link;

        struct module *owner;   /* Module owner of this control struct */

        int dev_idx;

        /* Per instance controls for this edac_device */
        int log_ue;             /* boolean for logging UEs */
        int log_ce;             /* boolean for logging CEs */
        int panic_on_ue;        /* boolean for panic'ing on an UE */
        unsigned poll_msec;     /* number of milliseconds to poll interval */
        unsigned long delay;    /* number of jiffies for poll_msec */

        /* Additional top controller level attributes, but specified
         * by the low level driver.
         *
         * Set by the low level driver to provide attributes at the
         * controller level, same level as 'ue_count' and 'ce_count' above.
         * An array of structures, NULL terminated
         *
         * If attributes are desired, then set to array of attributes
         * If no attributes are desired, leave NULL
         */
        struct edac_dev_sysfs_attribute *sysfs_attributes;

        /* pointer to main 'edac' subsys in sysfs */
        struct bus_type *edac_subsys;

        /* the internal state of this controller instance */
        int op_state;
        /* work struct for this instance */
        struct delayed_work work;

        /* pointer to edac polling checking routine:
         *      If NOT NULL: points to polling check routine
         *      If NULL: Then assumes INTERRUPT operation, where
         *              MC driver will receive events
         */
        void (*edac_check) (struct edac_device_ctl_info * edac_dev);

        struct device *dev;     /* pointer to device structure */

        const char *mod_name;   /* module name */
        const char *ctl_name;   /* edac controller  name */
        const char *dev_name;   /* pci/platform/etc... name */

        void *pvt_info;         /* pointer to 'private driver' info */

        unsigned long start_time;       /* edac_device load start time (jiffies) */

        struct completion removal_complete;

        /* sysfs top name under 'edac' directory
         * and instance name:
         *      cpu/cpu0/...
         *      cpu/cpu1/...
         *      cpu/cpu2/...
         *      ...
         */
        char name[EDAC_DEVICE_NAME_LEN + 1];

        /* Number of instances supported on this control structure
         * and the array of those instances
         */
        u32 nr_instances;
        struct edac_device_instance *instances;

        /* Event counters for the this whole EDAC Device */
        struct edac_device_counter counters;

        /* edac sysfs device control for the 'name'
         * device this structure controls
         */
        struct kobject kobj;
};

/* To get from the instance's wq to the beginning of the ctl structure */
#define to_edac_mem_ctl_work(w) \
                container_of(w, struct mem_ctl_info, work)

#define to_edac_device_ctl_work(w) \
                container_of(w,struct edac_device_ctl_info,work)

/*
 * The alloc() and free() functions for the 'edac_device' control info
 * structure. A MC driver will allocate one of these for each edac_device
 * it is going to control/register with the EDAC CORE.
 */
extern struct edac_device_ctl_info *edac_device_alloc_ctl_info(
                unsigned sizeof_private,
                char *edac_device_name, unsigned nr_instances,
                char *edac_block_name, unsigned nr_blocks,
                unsigned offset_value,
                struct edac_dev_sysfs_block_attribute *block_attributes,
                unsigned nr_attribs,
                int device_index);

/* The offset value can be:
 *      -1 indicating no offset value
 *      0 for zero-based block numbers
 *      1 for 1-based block number
 *      other for other-based block number
 */
#define BLOCK_OFFSET_VALUE_OFF  ((unsigned) -1)

extern void edac_device_free_ctl_info(struct edac_device_ctl_info *ctl_info);

/**
 * edac_device_add_device - Insert the 'edac_dev' structure into the
 *       edac_device global list and create sysfs entries associated with
 *       edac_device structure.
 *
 * @edac_dev: pointer to edac_device structure to be added to the list
 *      'edac_device' structure.
 *
 * Returns:
 *      0 on Success, or an error code on failure
 */
extern int edac_device_add_device(struct edac_device_ctl_info *edac_dev);

/**
 * edac_device_del_device - Remove sysfs entries for specified edac_device
 *      structure and then remove edac_device structure from global list
 *
 * @dev:
 *      Pointer to struct &device representing the edac device
 *      structure to remove.
 *
 * Returns:
 *      Pointer to removed edac_device structure,
 *      or %NULL if device not found.
 */
extern struct edac_device_ctl_info *edac_device_del_device(struct device *dev);

/**
 * edac_device_handle_ce_count - Log correctable errors.
 *
 * @edac_dev: pointer to struct &edac_device_ctl_info
 * @inst_nr: number of the instance where the CE error happened
 * @count: Number of errors to log.
 * @block_nr: number of the block where the CE error happened
 * @msg: message to be printed
 */
void edac_device_handle_ce_count(struct edac_device_ctl_info *edac_dev,
                                 unsigned int count, int inst_nr, int block_nr,
                                 const char *msg);

/**
 * edac_device_handle_ue_count - Log uncorrectable errors.
 *
 * @edac_dev: pointer to struct &edac_device_ctl_info
 * @inst_nr: number of the instance where the CE error happened
 * @count: Number of errors to log.
 * @block_nr: number of the block where the CE error happened
 * @msg: message to be printed
 */
void edac_device_handle_ue_count(struct edac_device_ctl_info *edac_dev,
                                 unsigned int count, int inst_nr, int block_nr,
                                 const char *msg);

/**
 * edac_device_handle_ce(): Log a single correctable error
 *
 * @edac_dev: pointer to struct &edac_device_ctl_info
 * @inst_nr: number of the instance where the CE error happened
 * @block_nr: number of the block where the CE error happened
 * @msg: message to be printed
 */
static inline void
edac_device_handle_ce(struct edac_device_ctl_info *edac_dev, int inst_nr,
                      int block_nr, const char *msg)
{
        edac_device_handle_ce_count(edac_dev, 1, inst_nr, block_nr, msg);
}

/**
 * edac_device_handle_ue(): Log a single uncorrectable error
 *
 * @edac_dev: pointer to struct &edac_device_ctl_info
 * @inst_nr: number of the instance where the UE error happened
 * @block_nr: number of the block where the UE error happened
 * @msg: message to be printed
 */
static inline void
edac_device_handle_ue(struct edac_device_ctl_info *edac_dev, int inst_nr,
                      int block_nr, const char *msg)
{
        edac_device_handle_ue_count(edac_dev, 1, inst_nr, block_nr, msg);
}

/**
 * edac_device_alloc_index: Allocate a unique device index number
 *
 * Returns:
 *      allocated index number
 */
extern int edac_device_alloc_index(void);
extern const char *edac_layer_name[];
#endif