On Fri, Sep 30, 2016 at 1:10 PM, Vishal Verma <vishal.l.verma(a)intel.com> wrote:
Starting a full Address Range Scrub (ARS) on hitting a memory error
machine check exception may not always be desirable. Provide a way
through sysfs to toggle the behavior between just adding the address
(cache line) where the MCE happened to the poison list and doing a full
scrub. The former (selective insertion of the address) is done
unconditionally.
Cc: linux-acpi(a)vger.kernel.org
Cc: Dan Williams <dan.j.williams(a)intel.com>
Cc: Linda Knippers <linda.knippers(a)hpe.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma(a)intel.com>
---
drivers/acpi/nfit/core.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/acpi/nfit/mce.c | 24 ++++++++++++++++-----
drivers/acpi/nfit/nfit.h | 6 ++++++
3 files changed, 79 insertions(+), 5 deletions(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 80cc7c0..6a12bc2 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -878,6 +878,58 @@ static ssize_t revision_show(struct device *dev,
}
static DEVICE_ATTR_RO(revision);
+static ssize_t hw_error_scrub_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+ struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);
+ struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
+
+ return sprintf(buf, "%d\n", acpi_desc->scrub_mode);
+}
+
+/*
+ * The 'hw_error_scrub' attribute can have the following values written to it:
+ * '1': Enable a full scrub to happen if an exception for a memory error is
+ * received.
+ * '2': Switch to the default mode where an exception will only insert
+ * the address of the memory error into the poison and badblocks lists.
Should the default be zero instead of 2, to match what ->scrub_mode is
initialized to by default?
+ */
+static ssize_t hw_error_scrub_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct nvdimm_bus_descriptor *nd_desc;
+ ssize_t rc;
+ long val;
+
+ rc = kstrtol(buf, 0, &val);
+ if (rc)
+ return rc;
+
+ device_lock(dev);
+ nd_desc = dev_get_drvdata(dev);
+ if (nd_desc) {
+ struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
+
+ switch (val) {
+ case MCE_SCRUB_ON:
+ acpi_desc->scrub_mode = MCE_SCRUB_ON;
If we're calling the sysfs attribute "hw_error_scrub" to avoid the
x86-specific MCE naming, I think we should call these defines
HW_ERROR_SCRUB_*.
+ break;
+ case MCE_SCRUB_OFF:
+ acpi_desc->scrub_mode = MCE_SCRUB_OFF;
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+ }
+ device_unlock(dev);
+ if (rc)
+ return rc;
+ return size;
+}
+static DEVICE_ATTR_RW(hw_error_scrub);
+
/*
* This shows the number of full Address Range Scrubs that have been
* completed since driver load time. Userspace can wait on this using
@@ -950,6 +1002,7 @@ static umode_t nfit_visible(struct kobject *kobj, struct attribute
*a, int n)
static struct attribute *acpi_nfit_attributes[] = {
&dev_attr_revision.attr,
&dev_attr_scrub.attr,
+ &dev_attr_hw_error_scrub.attr,
NULL,
};
@@ -2489,6 +2542,7 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data,
acpi_size sz)
goto out_unlock;
}
+ acpi_desc->scrub_mode = MCE_SCRUB_OFF;
If we make HW_ERROR_SCRUB_OFF == 0, then we don't need this line.