[PATCH v3] EDAC: expose per-dimm error counts in sysfs

From: Aaron Miller
Date: Thu Nov 03 2016 - 18:02:07 EST


The old 'csrowX' sysfs directories had per-csrow error counters, but the
new 'dimmX' directories do not currently expose error counts.

EDAC already keeps these counts, add them to sysfs so per-dimm counts
are still available when CONFIG_EDAC_LEGACY_SYSFS=n

Signed-off-by: Aaron Miller <aaronmiller@xxxxxx>
---

Notes:
v2: Add commit messsage and documentation
v3: Add ReST documentation on top of Mauro's patchset

Documentation/ABI/testing/sysfs-devices-edac | 17 +++++++++++++
Documentation/admin-guide/ras.rst | 20 +++++++++++++++
drivers/edac/edac_mc_sysfs.c | 38 ++++++++++++++++++++++++++++
3 files changed, 75 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-devices-edac b/Documentation/ABI/testing/sysfs-devices-edac
index 6568e0010e1a..46ff929fd52a 100644
--- a/Documentation/ABI/testing/sysfs-devices-edac
+++ b/Documentation/ABI/testing/sysfs-devices-edac
@@ -138,3 +138,20 @@ Contact: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
Description: This attribute file will display what type of memory is
currently on this csrow. Normally, either buffered or
unbuffered memory (for example, Unbuffered-DDR3).
+
+What: /sys/devices/system/edac/mc/mc*/(dimm|rank)*/dimm_ce_count
+Date: October 2016
+Contact: linux-edac@xxxxxxxxxxxxxxx
+Description: This attribute file displays the total count of correctable
+ errors that have occurred on this DIMM. This count is very important
+ to examine. CEs provide early indications that a DIMM is beginning
+ to fail. This count field should be monitored for non-zero values
+ and report such information to the system administrator.
+
+What: /sys/devices/system/edac/mc/mc*/(dimm|rank)*/dimm_ue_count
+Date: October 2016
+Contact: linux-edac@xxxxxxxxxxxxxxx
+Description: This attribute file displays the total count of uncorrectable
+ errors that have occurred on this DIMM. If panic_on_ue is set, this
+ counter will not have a chance to increment, since EDAC will panic the
+ system
diff --git a/Documentation/admin-guide/ras.rst b/Documentation/admin-guide/ras.rst
index d71340e86c27..9939348bd4a3 100644
--- a/Documentation/admin-guide/ras.rst
+++ b/Documentation/admin-guide/ras.rst
@@ -438,11 +438,13 @@ A typical EDAC system has the following structure under
â â âââ ce_count
â â âââ ce_noinfo_count
â â âââ dimm0
+ â â â âââ dimm_ce_count
â â â âââ dimm_dev_type
â â â âââ dimm_edac_mode
â â â âââ dimm_label
â â â âââ dimm_location
â â â âââ dimm_mem_type
+ â â â âââ dimm_ue_count
â â â âââ size
â â â âââ uevent
â â âââ max_location
@@ -457,11 +459,13 @@ A typical EDAC system has the following structure under
â â âââ ce_count
â â âââ ce_noinfo_count
â â âââ dimm0
+ â â â âââ dimm_ce_count
â â â âââ dimm_dev_type
â â â âââ dimm_edac_mode
â â â âââ dimm_label
â â â âââ dimm_location
â â â âââ dimm_mem_type
+ â â â âââ dimm_ue_count
â â â âââ size
â â â âââ uevent
â â âââ max_location
@@ -483,6 +487,22 @@ this ``X`` memory module:
This attribute file displays, in count of megabytes, the memory
that this csrow contains.

+- ``dimm_ue_count`` - Uncorrectable Errors count attribute file
+
+ This attribute file displays the total count of uncorrectable
+ errors that have occurred on this DIMM. If panic_on_ue is set
+ this counter will not have a chance to increment, since EDAC
+ will panic the system.
+
+- ``dimm_ce_count`` - Correctable Errors count attribute file
+
+ This attribute file displays the total count of correctable
+ errors that have occurred on this DIMM. This count is very
+ important to examine. CEs provide early indications that a
+ DIMM is beginning to fail. This count field should be
+ monitored for non-zero values and report such information
+ to the system administrator.
+
- ``dimm_dev_type`` - Device type attribute file

This attribute file will display what type of DRAM device is
diff --git a/drivers/edac/edac_mc_sysfs.c b/drivers/edac/edac_mc_sysfs.c
index 39dbab7d62f1..184fed2b005d 100644
--- a/drivers/edac/edac_mc_sysfs.c
+++ b/drivers/edac/edac_mc_sysfs.c
@@ -569,6 +569,40 @@ static ssize_t dimmdev_edac_mode_show(struct device *dev,
return sprintf(data, "%s\n", edac_caps[dimm->edac_mode]);
}

+static ssize_t dimmdev_ce_count_show(struct device *dev,
+ struct device_attribute *mattr,
+ char *data)
+{
+ struct dimm_info *dimm = to_dimm(dev);
+ u32 count;
+ int off;
+
+ off = EDAC_DIMM_OFF(dimm->mci->layers,
+ dimm->mci->n_layers,
+ dimm->location[0],
+ dimm->location[1],
+ dimm->location[2]);
+ count = dimm->mci->ce_per_layer[dimm->mci->n_layers-1][off];
+ return sprintf(data, "%u\n", count);
+}
+
+static ssize_t dimmdev_ue_count_show(struct device *dev,
+ struct device_attribute *mattr,
+ char *data)
+{
+ struct dimm_info *dimm = to_dimm(dev);
+ u32 count;
+ int off;
+
+ off = EDAC_DIMM_OFF(dimm->mci->layers,
+ dimm->mci->n_layers,
+ dimm->location[0],
+ dimm->location[1],
+ dimm->location[2]);
+ count = dimm->mci->ue_per_layer[dimm->mci->n_layers-1][off];
+ return sprintf(data, "%u\n", count);
+}
+
/* dimm/rank attribute files */
static DEVICE_ATTR(dimm_label, S_IRUGO | S_IWUSR,
dimmdev_label_show, dimmdev_label_store);
@@ -577,6 +611,8 @@ static DEVICE_ATTR(size, S_IRUGO, dimmdev_size_show, NULL);
static DEVICE_ATTR(dimm_mem_type, S_IRUGO, dimmdev_mem_type_show, NULL);
static DEVICE_ATTR(dimm_dev_type, S_IRUGO, dimmdev_dev_type_show, NULL);
static DEVICE_ATTR(dimm_edac_mode, S_IRUGO, dimmdev_edac_mode_show, NULL);
+static DEVICE_ATTR(dimm_ce_count, S_IRUGO, dimmdev_ce_count_show, NULL);
+static DEVICE_ATTR(dimm_ue_count, S_IRUGO, dimmdev_ue_count_show, NULL);

/* attributes of the dimm<id>/rank<id> object */
static struct attribute *dimm_attrs[] = {
@@ -586,6 +622,8 @@ static struct attribute *dimm_attrs[] = {
&dev_attr_dimm_mem_type.attr,
&dev_attr_dimm_dev_type.attr,
&dev_attr_dimm_edac_mode.attr,
+ &dev_attr_dimm_ce_count.attr,
+ &dev_attr_dimm_ue_count.attr,
NULL,
};

--
2.9.3