From 9ffd6350a103cb9e73e3abb4573c900cfead2f9b Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Fri, 30 Sep 2016 17:19:29 -0600 Subject: [PATCH] nfit: don't start a full scrub by default for an MCE 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@vger.kernel.org Cc: Linda Knippers Cc: Rafael J. Wysocki Signed-off-by: Vishal Verma Signed-off-by: Dan Williams --- drivers/acpi/nfit/core.c | 53 ++++++++++++++++++++++++++++++++++++++++ drivers/acpi/nfit/mce.c | 24 ++++++++++++++---- drivers/acpi/nfit/nfit.h | 6 +++++ 3 files changed, 78 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index ceb6671ab355..02838f928d7e 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: + * '0': Switch to the default mode where an exception will only insert + * the address of the memory error into the poison and badblocks lists. + * '1': Enable a full scrub to happen if an exception for a memory error is + * received. + */ +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 HW_ERROR_SCRUB_ON: + acpi_desc->scrub_mode = HW_ERROR_SCRUB_ON; + break; + case HW_ERROR_SCRUB_OFF: + acpi_desc->scrub_mode = HW_ERROR_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, }; diff --git a/drivers/acpi/nfit/mce.c b/drivers/acpi/nfit/mce.c index 4c745bf389fe..2e25e252945f 100644 --- a/drivers/acpi/nfit/mce.c +++ b/drivers/acpi/nfit/mce.c @@ -14,6 +14,7 @@ */ #include #include +#include #include #include "nfit.h" @@ -62,12 +63,25 @@ static int nfit_handle_mce(struct notifier_block *nb, unsigned long val, } mutex_unlock(&acpi_desc->init_mutex); - /* - * We can ignore an -EBUSY here because if an ARS is already - * in progress, just let that be the last authoritative one - */ - if (found_match) + if (!found_match) + continue; + + /* If this fails due to an -ENOMEM, there is little we can do */ + nvdimm_bus_add_poison(acpi_desc->nvdimm_bus, + ALIGN(mce->addr, L1_CACHE_BYTES), + L1_CACHE_BYTES); + nvdimm_region_notify(nfit_spa->nd_region, + NVDIMM_REVALIDATE_POISON); + + if (acpi_desc->scrub_mode == HW_ERROR_SCRUB_ON) { + /* + * We can ignore an -EBUSY here because if an ARS is + * already in progress, just let that be the last + * authoritative one + */ acpi_nfit_ars_rescan(acpi_desc); + } + break; } mutex_unlock(&acpi_desc_lock); diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h index bb101170cd0b..14296f5267c8 100644 --- a/drivers/acpi/nfit/nfit.h +++ b/drivers/acpi/nfit/nfit.h @@ -161,6 +161,7 @@ struct acpi_nfit_desc { struct list_head list; struct kernfs_node *scrub_count_state; unsigned int scrub_count; + unsigned int scrub_mode; unsigned int cancel:1; unsigned long dimm_cmd_force_en; unsigned long bus_cmd_force_en; @@ -168,6 +169,11 @@ struct acpi_nfit_desc { void *iobuf, u64 len, int rw); }; +enum scrub_mode { + HW_ERROR_SCRUB_OFF, + HW_ERROR_SCRUB_ON, +}; + enum nd_blk_mmio_selector { BDW, DCR, -- 2.20.1