[PATCH v5] nfit, libnvdimm: allow an ARS scrub to be triggered on demand

From: Vishal Verma <vishal.l.verma(a)intel.com&gt; 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(a)intel.com&gt; Signed-off-by: Vishal Verma <vishal.l.verma(a)intel.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt; --- drivers/acpi/nfit.c | 161 +++++++++++++++++++++++++++++++++++++++++++-- drivers/acpi/nfit.h | 4 + drivers/nvdimm/core.c | 7 ++ include/linux/libnvdimm.h | 1 4 files changed, 165 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index be7c2fde16e7..19d0dfdf9633 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -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; diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h index b63a583a678f..6ecf337c97aa 100644 --- a/drivers/acpi/nfit.h +++ b/drivers/acpi/nfit.h @@ -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; diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c index 2c98f958fabb..715583f69d28 100644 --- a/drivers/nvdimm/core.c +++ b/drivers/nvdimm/core.c @@ -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') diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h index 2ab869dece4a..b519e137b9b7 100644 --- a/include/linux/libnvdimm.h +++ b/include/linux/libnvdimm.h @@ -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);