drivers/edac: add edac_device class

This patch adds the new 'class' of object to be managed, named: 'edac_device'.

As a peer of the 'edac_mc' class of object, it provides a non-memory centric
view of an ERROR DETECTING device in hardware. It provides a sysfs interface
and an abstraction for varioius EDAC type devices.

Multiple 'instances' within the class are possible, with each 'instance'
able to have multiple 'blocks', and each 'block' having 'attributes'.

At the 'block' level there are the 'ce_count' and 'ue_count' fields
which the device driver can update and/or call edac_device_handle_XX()
functions. At each higher level are additional 'total' count fields,
which are a summation of counts below that level.

This 'edac_device' has been used to capture and present ECC errors
which are found in a a L1 and L2 system on a per CORE/CPU basis.

Signed-off-by: Douglas Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 669 insertions, 0 deletions

diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
new file mode 100644
index 0000000..c579c49
--- /dev/null
+++ b/drivers/edac/edac_device.c
@@ -0,0 +1,669 @@
+
+/*
+ * 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 <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"
+
+/* lock to memory controller's control array */
+static DECLARE_MUTEX(device_ctls_mutex);
+static struct list_head edac_device_list = LIST_HEAD_INIT(edac_device_list);
+
+
+static inline void lock_device_list(void)
+{
+	down(&device_ctls_mutex);
+}
+
+static inline void unlock_device_list(void)
+{
+	up(&device_ctls_mutex);
+}
+
+
+#ifdef CONFIG_EDAC_DEBUG
+static void edac_device_dump_device(struct edac_device_ctl_info *edac_dev)
+{
+	debugf3("\tedac_dev = %p dev_idx=%d \n", edac_dev,edac_dev->dev_idx);
+	debugf4("\tedac_dev->edac_check = %p\n", edac_dev->edac_check);
+	debugf3("\tdev = %p\n", edac_dev->dev);
+	debugf3("\tmod_name:ctl_name = %s:%s\n",
+		edac_dev->mod_name, edac_dev->ctl_name);
+	debugf3("\tpvt_info = %p\n\n", edac_dev->pvt_info);
+}
+#endif  /* CONFIG_EDAC_DEBUG */
+
+/*
+ * 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.
+ */
+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,
+	struct edac_attrib_spec *attrib_spec,
+	unsigned nr_attribs)
+{
+	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_attrib *dev_attrib, *attrib_p, *attrib;
+	unsigned total_size;
+	unsigned count;
+	unsigned instance, block, attr;
+	void *pvt;
+
+	debugf1("%s() instances=%d blocks=%d\n",
+		__func__,nr_instances,nr_blocks);
+
+	/* Figure out the offsets of the various items from the start of an
+	 * ctl_info structure.  We want the alignment of each item
+	 * to be at least as stringent as what the compiler would
+	 * provide if we could simply hardcode everything into a single struct.
+	 */
+	dev_ctl = (struct edac_device_ctl_info *) 0;
+
+	/* Calc the 'end' offset past the ctl_info structure */
+	dev_inst = (struct edac_device_instance *)
+			edac_align_ptr(&dev_ctl[1],sizeof(*dev_inst));
+
+	/* Calc the 'end' offset past the instance array */
+	dev_blk = (struct edac_device_block *)
+			edac_align_ptr(&dev_inst[nr_instances],sizeof(*dev_blk));
+
+	/* Calc the 'end' offset past the dev_blk array */
+	count = nr_instances * nr_blocks;
+	dev_attrib = (struct edac_attrib *)
+			edac_align_ptr(&dev_blk[count],sizeof(*dev_attrib));
+
+	/* Check for case of NO attributes specified */
+	if (nr_attribs > 0)
+		count *= nr_attribs;
+
+	/* Calc the 'end' offset past the attributes array */
+	pvt = edac_align_ptr(&dev_attrib[count],sz_private);
+	total_size = ((unsigned long) pvt) + sz_private;
+
+	/* Allocate the amount of memory for the set of control structures */
+	if ((dev_ctl = kmalloc(total_size, GFP_KERNEL)) == NULL)
+		return NULL;
+
+	/* Adjust pointers so they point within the memory we just allocated
+	 * rather than an imaginary chunk of memory located at address 0.
+	 */
+	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_attrib *)
+			(((char *) dev_ctl) + ((unsigned long) dev_attrib));
+	pvt = sz_private ?
+			(((char *) dev_ctl) + ((unsigned long) pvt)) : NULL;
+
+	memset(dev_ctl, 0, total_size);		/* clear all fields */
+	dev_ctl->nr_instances = nr_instances;
+	dev_ctl->instances = dev_inst;
+	dev_ctl->pvt_info = pvt;
+
+	/* Name of this edac device, ensure null terminated */
+	snprintf(dev_ctl->name,sizeof(dev_ctl->name),"%s", edac_device_name);
+	dev_ctl->name[sizeof(dev_ctl->name)-1] = '\0';
+
+	/* 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);
+		inst->name[sizeof(inst->name)-1] = '\0';
+
+		/* Initialize every block in each instance */
+		for (		block = 0;
+				block < nr_blocks;
+				block++) {
+			blk = &blk_p[block];
+			blk->instance = inst;
+			blk->nr_attribs = nr_attribs;
+			attrib_p = &dev_attrib[block * nr_attribs];
+			blk->attribs = attrib_p;
+			snprintf(blk->name, sizeof(blk->name),
+				"%s%d", edac_block_name,block+1);
+			blk->name[sizeof(blk->name)-1] = '\0';
+
+			debugf1("%s() instance=%d block=%d name=%s\n",
+				__func__, instance,block,blk->name);
+
+			if (attrib_spec != NULL) {
+				/* when there is an attrib_spec passed int then
+				 * Initialize every attrib of each block
+				 */
+				for (attr = 0; attr < nr_attribs; attr++) {
+					attrib = &attrib_p[attr];
+					attrib->block = blk;
+
+					/* Link each attribute to the caller's
+					 * spec entry, for name and type
+				 	 */
+					attrib->spec = &attrib_spec[attr];
+				}
+			}
+		}
+	}
+
+	/* Mark this instance as merely ALLOCATED */
+	dev_ctl->op_state = OP_ALLOC;
+
+	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) {
+	kfree(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 *'
+ */
+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;
+
+	debugf3("%s()\n", __func__);
+
+	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.
+ *	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 */
+	if (unlikely((rover = find_edac_device_by_dev(edac_dev->dev)) != 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",
+		rover->dev->bus_id, dev_name(rover->dev),
+		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;
+}
+
+/*
+ * complete_edac_device_list_del
+ */
+static void complete_edac_device_list_del(struct rcu_head *head)
+{
+	struct edac_device_ctl_info *edac_dev;
+
+	edac_dev = container_of(head, struct edac_device_ctl_info, rcu);
+	INIT_LIST_HEAD(&edac_dev->link);
+	complete(&edac_dev->complete);
+}
+
+/*
+ * 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);
+	init_completion(&edac_device->complete);
+	call_rcu(&edac_device->rcu, complete_edac_device_list_del);
+	wait_for_completion(&edac_device->complete);
+}
+
+/**
+ * edac_device_find
+ *	Search for a edac_device_ctl_info structure whose index is 'idx'.
+ *
+ * If found, return a pointer to the structure.
+ * Else return NULL.
+ *
+ * Caller must hold device_ctls_mutex.
+ */
+struct edac_device_ctl_info * edac_device_find(int idx)
+{
+	struct list_head *item;
+	struct edac_device_ctl_info *edac_dev;
+
+	/* Iterate over list, looking for exact match of ID */
+	list_for_each(item, &edac_device_list) {
+		edac_dev = list_entry(item, struct edac_device_ctl_info, link);
+
+		if (edac_dev->dev_idx >= idx) {
+			if (edac_dev->dev_idx == idx)
+				return edac_dev;
+
+			/* not on list, so terminate early */
+			break;
+		}
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(edac_device_find);
+
+
+/*
+ * edac_workq_function
+ *	performs the operation scheduled by a workq request
+ */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20))
+static void edac_workq_function(struct work_struct *work_req)
+{
+	struct delayed_work *d_work = (struct delayed_work*) work_req;
+	struct edac_device_ctl_info *edac_dev =
+		to_edac_device_ctl_work(d_work);
+#else
+static void edac_workq_function(void *ptr)
+{
+	struct edac_device_ctl_info *edac_dev =
+		(struct edac_device_ctl_info *) ptr;
+#endif
+
+	//debugf0("%s() here and running\n", __func__);
+	lock_device_list();
+
+	/* 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);
+	}
+
+	unlock_device_list();
+
+	/* Reschedule */
+	queue_delayed_work(edac_workqueue,&edac_dev->work, edac_dev->delay);
+}
+
+/*
+ * edac_workq_setup
+ *	initialize a workq item for this edac_device instance
+ *	passing in the new delay period in msec
+ */
+void edac_workq_setup(struct edac_device_ctl_info *edac_dev, unsigned msec)
+{
+	debugf0("%s()\n", __func__);
+
+	edac_dev->poll_msec = msec;
+	edac_device_calc_delay(edac_dev);	/* Calc delay jiffies */
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20))
+	INIT_DELAYED_WORK(&edac_dev->work,edac_workq_function);
+#else
+	INIT_WORK(&edac_dev->work,edac_workq_function,edac_dev);
+#endif
+	queue_delayed_work(edac_workqueue,&edac_dev->work, edac_dev->delay);
+}
+
+/*
+ * edac_workq_teardown
+ *	stop the workq processing on this edac_dev
+ */
+void edac_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
+ */
+
+void edac_device_reset_delay_period(
+		struct edac_device_ctl_info *edac_dev,
+		unsigned long value)
+{
+	lock_device_list();
+
+	/* cancel the current workq request */
+	edac_workq_teardown(edac_dev);
+
+	/* restart the workq request, with new delay value */
+	edac_workq_setup(edac_dev, value);
+
+	unlock_device_list();
+}
+
+/*
+ * edac_op_state_toString(edac_dev)
+ */
+static char *edac_op_state_toString(struct edac_device_ctl_info *edac_dev)
+{
+	int opstate = edac_dev->op_state;
+
+	if (opstate == OP_RUNNING_POLL)
+		return "POLLED";
+	else if (opstate == OP_RUNNING_INTERRUPT)
+		return "INTERRUPT";
+	else if (opstate == OP_RUNNING_POLL_INTR)
+		return "POLL-INTR";
+	else if (opstate == OP_ALLOC)
+		return "ALLOC";
+	else if (opstate == OP_OFFLINE)
+		return "OFFLINE";
+
+	return "UNKNOWN";
+}
+
+/**
+ * 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_device: pointer to the edac_device structure to be added to the list
+ * @edac_idx: A unique numeric identifier to be assigned to the
+ * 'edac_device' structure.
+ *
+ * Return:
+ *	0	Success
+ *	!0	Failure
+ */
+int edac_device_add_device(struct edac_device_ctl_info *edac_dev, int edac_idx)
+{
+	debugf0("%s()\n", __func__);
+
+	edac_dev->dev_idx = edac_idx;
+#ifdef CONFIG_EDAC_DEBUG
+	if (edac_debug_level >= 3)
+		edac_device_dump_device(edac_dev);
+#endif
+	lock_device_list();
+
+	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_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,
+		dev_name(edac_dev->dev),
+		edac_op_state_toString(edac_dev)
+		);
+
+	unlock_device_list();
+	return 0;
+
+fail1:
+	/* Some error, so remove the entry from the lsit */
+	del_edac_device_from_global_list(edac_dev);
+
+fail0:
+	unlock_device_list();
+	return 1;
+}
+EXPORT_SYMBOL_GPL(edac_device_add_device);
+
+/**
+ * edac_device_del_device:
+ *	Remove sysfs entries for specified edac_device structure and
+ *	then remove edac_device structure from global list
+ *
+ * @pdev:
+ *	Pointer to 'struct device' representing edac_device
+ *	structure to remove.
+ *
+ * Return:
+ *	Pointer to removed edac_device structure,
+ *	OR NULL if device not found.
+ */
+struct edac_device_ctl_info * edac_device_del_device(struct device *dev)
+{
+	struct edac_device_ctl_info *edac_dev;
+
+	debugf0("MC: %s()\n", __func__);
+
+	lock_device_list();
+
+	if ((edac_dev = find_edac_device_by_dev(dev)) == NULL) {
+		unlock_device_list();
+		return NULL;
+	}
+
+	/* mark this instance as OFFLINE */
+	edac_dev->op_state = OP_OFFLINE;
+
+	/* clear workq processing on this instance */
+	edac_workq_teardown(edac_dev);
+
+	/* Tear down the sysfs entries for this instance */
+	edac_device_remove_sysfs(edac_dev);
+
+	/* deregister from global list */
+	del_edac_device_from_global_list(edac_dev);
+
+	unlock_device_list();
+
+	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,
+		dev_name(edac_dev->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++;
+	}
+
+	/* Propogate 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 ctl: %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++;
+	}
+
+	/* Propogate 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 ctl: %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);
+