Commit 37b137ff authored by Vishal Verma's avatar Vishal Verma Committed by Dan Williams
Browse files

nfit, libnvdimm: allow an ARS scrub to be triggered on demand 



Normally, an ARS (Address Range Scrub) only happens at
boot/initialization time. There can however arise situations where a
bus-wide rescan is needed - notably, in the case of discovering a latent
media error, we should do a full rescan to figure out what other sectors
are bad, and thus potentially avoid triggering an mce on them in the
future. Also provide a sysfs trigger to start a bus-wide scrub.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 18515942

drivers/acpi/nfit.c

+154 −7
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/ndctl.h>

#include <linux/sysfs.h>

#include <linux/delay.h>

#include <linux/list.h>

#include <linux/acpi.h>
@@ -874,14 +875,87 @@ static ssize_t revision_show(struct device *dev, 
}

static DEVICE_ATTR_RO(revision);



/*

 * This shows the number of full Address Range Scrubs that have been

 * completed since driver load time. Userspace can wait on this using

 * select/poll etc. A '+' at the end indicates an ARS is in progress

 */

static ssize_t scrub_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct nvdimm_bus_descriptor *nd_desc;

	ssize_t rc = -ENXIO;



	device_lock(dev);

	nd_desc = dev_get_drvdata(dev);

	if (nd_desc) {

		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);



		rc = sprintf(buf, "%d%s", acpi_desc->scrub_count,

				(work_busy(&acpi_desc->work)) ? "+\n" : "\n");

	}

	device_unlock(dev);

	return rc;

}



static int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc);



static ssize_t 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;

	if (val != 1)

		return -EINVAL;



	device_lock(dev);

	nd_desc = dev_get_drvdata(dev);

	if (nd_desc) {

		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);



		rc = acpi_nfit_ars_rescan(acpi_desc);

	}

	device_unlock(dev);

	if (rc)

		return rc;

	return size;

}

static DEVICE_ATTR_RW(scrub);



static bool ars_supported(struct nvdimm_bus *nvdimm_bus)

{

	struct nvdimm_bus_descriptor *nd_desc = to_nd_desc(nvdimm_bus);

	const unsigned long mask = 1 << ND_CMD_ARS_CAP | 1 << ND_CMD_ARS_START

		| 1 << ND_CMD_ARS_STATUS;



	return (nd_desc->cmd_mask & mask) == mask;

}



static umode_t nfit_visible(struct kobject *kobj, struct attribute *a, int n)

{

	struct device *dev = container_of(kobj, struct device, kobj);

	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);



	if (a == &dev_attr_scrub.attr && !ars_supported(nvdimm_bus))

		return 0;

	return a->mode;

}



static struct attribute *acpi_nfit_attributes[] = {

	&dev_attr_revision.attr,

	&dev_attr_scrub.attr,

	NULL,

};



static struct attribute_group acpi_nfit_attribute_group = {

	.name = "nfit",

	.attrs = acpi_nfit_attributes,

	.is_visible = nfit_visible,

};



static const struct attribute_group *acpi_nfit_attribute_groups[] = {
@@ -2054,7 +2128,7 @@ static void acpi_nfit_async_scrub(struct acpi_nfit_desc *acpi_desc, 
	unsigned int tmo = scrub_timeout;

	int rc;



	if (nfit_spa->ars_done || !nfit_spa->nd_region)

	if (!nfit_spa->ars_required || !nfit_spa->nd_region)

		return;



	rc = ars_start(acpi_desc, nfit_spa);
@@ -2143,7 +2217,9 @@ static void acpi_nfit_scrub(struct work_struct *work) 
	 * firmware initiated scrubs to complete and then we go search for the

	 * affected spa regions to mark them scanned.  In the second phase we

	 * initiate a directed scrub for every range that was not scrubbed in

	 * phase 1.

	 * phase 1. If we're called for a 'rescan', we harmlessly pass through

	 * the first phase, but really only care about running phase 2, where

	 * regions can be notified of new poison.

	 */



	/* process platform firmware initiated scrubs */
@@ -2246,14 +2322,17 @@ static void acpi_nfit_scrub(struct work_struct *work) 
		 * Flag all the ranges that still need scrubbing, but

		 * register them now to make data available.

		 */

		if (nfit_spa->nd_region)

			nfit_spa->ars_done = 1;

		else

		if (!nfit_spa->nd_region) {

			nfit_spa->ars_required = 1;

			acpi_nfit_register_region(acpi_desc, nfit_spa);

		}

	}



	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)

		acpi_nfit_async_scrub(acpi_desc, nfit_spa);

	acpi_desc->scrub_count++;

	if (acpi_desc->scrub_count_state)

		sysfs_notify_dirent(acpi_desc->scrub_count_state);

	mutex_unlock(&acpi_desc->init_mutex);

}
@@ -2291,12 +2370,48 @@ static int acpi_nfit_check_deletions(struct acpi_nfit_desc *acpi_desc, 
	return 0;

}



static int acpi_nfit_desc_init_scrub_attr(struct acpi_nfit_desc *acpi_desc)

{

	struct device *dev = acpi_desc->dev;

	struct kernfs_node *nfit;

	struct device *bus_dev;



	if (!ars_supported(acpi_desc->nvdimm_bus))

		return 0;



	bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);

	nfit = sysfs_get_dirent(bus_dev->kobj.sd, "nfit");

	if (!nfit) {

		dev_err(dev, "sysfs_get_dirent 'nfit' failed\n");

		return -ENODEV;

	}

	acpi_desc->scrub_count_state = sysfs_get_dirent(nfit, "scrub");

	sysfs_put(nfit);

	if (!acpi_desc->scrub_count_state) {

		dev_err(dev, "sysfs_get_dirent 'scrub' failed\n");

		return -ENODEV;

	}



	return 0;

}



static void acpi_nfit_destruct(void *data)

{

	struct acpi_nfit_desc *acpi_desc = data;

	struct device *bus_dev = to_nvdimm_bus_dev(acpi_desc->nvdimm_bus);



	acpi_desc->cancel = 1;

	/*

	 * Bounce the nvdimm bus lock to make sure any in-flight

	 * acpi_nfit_ars_rescan() submissions have had a chance to

	 * either submit or see ->cancel set.

	 */

	device_lock(bus_dev);

	device_unlock(bus_dev);



	flush_workqueue(nfit_wq);

	if (acpi_desc->scrub_count_state)

		sysfs_put(acpi_desc->scrub_count_state);

	nvdimm_bus_unregister(acpi_desc->nvdimm_bus);

	acpi_desc->nvdimm_bus = NULL;

}
@@ -2309,14 +2424,21 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz) 
	int rc;



	if (!acpi_desc->nvdimm_bus) {

		acpi_nfit_init_dsms(acpi_desc);



		acpi_desc->nvdimm_bus = nvdimm_bus_register(dev,

				&acpi_desc->nd_desc);

		if (!acpi_desc->nvdimm_bus)

			return -ENOMEM;



		rc = devm_add_action_or_reset(dev, acpi_nfit_destruct,

				acpi_desc);

		if (rc)

			return rc;



		rc = acpi_nfit_desc_init_scrub_attr(acpi_desc);

		if (rc)

			return rc;

	}



	mutex_lock(&acpi_desc->init_mutex);
@@ -2360,8 +2482,6 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz) 
	if (rc)

		goto out_unlock;



	acpi_nfit_init_dsms(acpi_desc);



	rc = acpi_nfit_register_dimms(acpi_desc);

	if (rc)

		goto out_unlock;
@@ -2429,6 +2549,33 @@ static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc, 
	return 0;

}



static int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc)

{

	struct device *dev = acpi_desc->dev;

	struct nfit_spa *nfit_spa;



	if (work_busy(&acpi_desc->work))

		return -EBUSY;



	if (acpi_desc->cancel)

		return 0;



	mutex_lock(&acpi_desc->init_mutex);

	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {

		struct acpi_nfit_system_address *spa = nfit_spa->spa;



		if (nfit_spa_type(spa) != NFIT_SPA_PM)

			continue;



		nfit_spa->ars_required = 1;

	}

	queue_work(nfit_wq, &acpi_desc->work);

	dev_dbg(dev, "%s: ars_scan triggered\n", __func__);

	mutex_unlock(&acpi_desc->init_mutex);



	return 0;

}



void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)

{

	struct nvdimm_bus_descriptor *nd_desc;

drivers/acpi/nfit.h

+3 −1
Original line number Diff line number Diff line
@@ -80,7 +80,7 @@ enum { 
struct nfit_spa {

	struct list_head list;

	struct nd_region *nd_region;

	unsigned int ars_done:1;

	unsigned int ars_required:1;

	u32 clear_err_unit;

	u32 max_ars;

	struct acpi_nfit_system_address spa[0];
@@ -148,6 +148,8 @@ struct acpi_nfit_desc { 
	struct nd_cmd_ars_status *ars_status;

	size_t ars_status_size;

	struct work_struct work;

	struct kernfs_node *scrub_count_state;

	unsigned int scrub_count;

	unsigned int cancel:1;

	unsigned long dimm_cmd_force_en;

	unsigned long bus_cmd_force_en;

drivers/nvdimm/core.c

+7 −0
Original line number Diff line number Diff line
@@ -201,6 +201,13 @@ struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus) 
}

EXPORT_SYMBOL_GPL(to_nd_desc);



struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus)

{

	/* struct nvdimm_bus definition is private to libnvdimm */

	return &nvdimm_bus->dev;

}

EXPORT_SYMBOL_GPL(to_nvdimm_bus_dev);



static bool is_uuid_sep(char sep)

{

	if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')

include/linux/libnvdimm.h

+1 −0
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ struct nvdimm *to_nvdimm(struct device *dev); 
struct nd_region *to_nd_region(struct device *dev);

struct nd_blk_region *to_nd_blk_region(struct device *dev);

struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus);

struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus);

const char *nvdimm_name(struct nvdimm *nvdimm);

unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm);

void *nvdimm_provider_data(struct nvdimm *nvdimm);

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