/*
   * 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 <norsk5@xmission.com>
   *
   * edac_device API implementation
   * 19 Jan 2007
   */

  #include <asm/page.h>

  #include <linux/uaccess.h>

  #include <linux/ctype.h>
  #include <linux/highmem.h>
  #include <linux/init.h>
  #include <linux/jiffies.h>

  #include <linux/module.h>

  #include <linux/slab.h>

  #include <linux/smp.h>

  #include <linux/spinlock.h>

  #include <linux/sysctl.h>

  #include <linux/timer.h>

  #include "edac_device.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
  ",
  		 edac_dev, edac_dev->dev_idx);
  	edac_dbg(4, "\tedac_dev->edac_check = %p
  ", edac_dev->edac_check);
  	edac_dbg(3, "\tdev = %p
  ", edac_dev->dev);
  	edac_dbg(3, "\tmod_name:ctl_name = %s:%s
  ",
  		 edac_dev->mod_name, edac_dev->ctl_name);
  	edac_dbg(3, "\tpvt_info = %p
  
  ", edac_dev->pvt_info);

  }

  #endif				/* CONFIG_EDAC_DEBUG */

  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
  ", 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
  ",
  		 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'
  ",
  				 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
  ",
  				 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
  ",
  					 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);

  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, "
  ");

  
  	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
  ",

  			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
  "
  			"    duplicate dev_idx %d in %s()
  ", 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)

  		edac_queue_work(&edac_dev->work, round_jiffies_relative(edac_dev->delay));

  	else

  		edac_queue_work(&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
   */

  static void edac_device_workq_setup(struct edac_device_ctl_info *edac_dev,
  				    unsigned msec)

  {

  	edac_dbg(0, "
  ");

  	/* 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)

  		edac_queue_work(&edac_dev->work, round_jiffies_relative(edac_dev->delay));

  	else

  		edac_queue_work(&edac_dev->work, edac_dev->delay);

  }
  
  /*

   * edac_device_workq_teardown

   *	stop the workq processing on this edac_dev
   */

  static void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)

  {

  	if (!edac_dev->edac_check)
  		return;

  	edac_dev->op_state = OP_OFFLINE;

  	edac_stop_work(&edac_dev->work);

  }
  
  /*
   * 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)

  {

  	unsigned long jiffs = msecs_to_jiffies(value);

  	if (value == 1000)
  		jiffs = round_jiffies_relative(value);

  	edac_dev->poll_msec = value;
  	edac_dev->delay	    = jiffs;

  	edac_mod_work(&edac_dev->work, jiffs);

  }

  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, "
  ");

  #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
  ");

  		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)
  ",
  		edac_dev->mod_name, edac_dev->ctl_name, edac_dev->dev_name,
  		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, "
  ");

  	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
  ",
  		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;
  }

  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)

  {
  	struct edac_device_instance *instance;
  	struct edac_device_block *block = NULL;

  	if (!count)
  		return;

  	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)
  ", 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)
  ",
  				inst_nr, block_nr,
  				instance->nr_blocks);

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

  		block->counters.ce_count += count;

  	}

  	/* Propagate the count up the 'totals' tree */

  	instance->counters.ce_count += count;
  	edac_dev->counters.ce_count += count;

  
  	if (edac_device_get_log_ce(edac_dev))
  		edac_device_printk(edac_dev, KERN_WARNING,

  				   "CE: %s instance: %s block: %s count: %d '%s'
  ",
  				   edac_dev->ctl_name, instance->name,
  				   block ? block->name : "N/A", count, msg);

  }

  EXPORT_SYMBOL_GPL(edac_device_handle_ce_count);

  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)

  {
  	struct edac_device_instance *instance;
  	struct edac_device_block *block = NULL;

  	if (!count)
  		return;

  	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)
  ", 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)
  ",
  				inst_nr, block_nr,
  				instance->nr_blocks);

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

  		block->counters.ue_count += count;

  	}

  	/* Propagate the count up the 'totals' tree */

  	instance->counters.ue_count += count;
  	edac_dev->counters.ue_count += count;

  
  	if (edac_device_get_log_ue(edac_dev))
  		edac_device_printk(edac_dev, KERN_EMERG,

  				   "UE: %s instance: %s block: %s count: %d '%s'
  ",
  				   edac_dev->ctl_name, instance->name,
  				   block ? block->name : "N/A", count, msg);

  
  	if (edac_device_get_panic_on_ue(edac_dev))

  		panic("EDAC %s: UE instance: %s block %s count: %d '%s'
  ",
  		      edac_dev->ctl_name, instance->name,
  		      block ? block->name : "N/A", count, msg);

  }

  EXPORT_SYMBOL_GPL(edac_device_handle_ue_count);