From eaf961536e1622ad21247ac8d44acd48ba65566e Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 1 May 2015 13:11:27 -0400 Subject: libnvdimm, nfit: add interleave-set state-tracking infrastructure On platforms that have firmware support for reading/writing per-dimm label space, a portion of the dimm may be accessible via an interleave set PMEM mapping in addition to the dimm's BLK (block-data-window aperture(s)) interface. A label, stored in a "configuration data region" on the dimm, disambiguates which dimm addresses are accessed through which exclusive interface. Add infrastructure that allows the kernel to block modifications to a label in the set while any member dimm is active. Note that this is meant only for enforcing "no modifications of active labels" via the coarse ioctl command. Adding/deleting namespaces from an active interleave set is always possible via sysfs. Another aspect of tracking interleave sets is tracking their integrity when DIMMs in a set are physically re-ordered. For this purpose we generate an "interleave-set cookie" that can be recorded in a label and validated against the current configuration. It is the bus provider implementation's responsibility to calculate the interleave set cookie and attach it to a given region. Cc: Neil Brown Cc: Cc: Greg KH Cc: Robert Moore Cc: Rafael J. Wysocki Acked-by: Christoph Hellwig Acked-by: Rafael J. Wysocki Signed-off-by: Dan Williams --- drivers/nvdimm/region_devs.c | 69 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) (limited to 'drivers/nvdimm/region_devs.c') diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index b5c5b90..1571424 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -10,7 +10,10 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */ +#include +#include #include +#include #include #include "nd-core.h" #include "nd.h" @@ -133,6 +136,21 @@ static ssize_t nstype_show(struct device *dev, } static DEVICE_ATTR_RO(nstype); +static ssize_t set_cookie_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct nd_region *nd_region = to_nd_region(dev); + struct nd_interleave_set *nd_set = nd_region->nd_set; + + if (is_nd_pmem(dev) && nd_set) + /* pass, should be precluded by region_visible */; + else + return -ENXIO; + + return sprintf(buf, "%#llx\n", nd_set->cookie); +} +static DEVICE_ATTR_RO(set_cookie); + static ssize_t init_namespaces_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -154,15 +172,65 @@ static struct attribute *nd_region_attributes[] = { &dev_attr_size.attr, &dev_attr_nstype.attr, &dev_attr_mappings.attr, + &dev_attr_set_cookie.attr, &dev_attr_init_namespaces.attr, NULL, }; +static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, typeof(*dev), kobj); + struct nd_region *nd_region = to_nd_region(dev); + struct nd_interleave_set *nd_set = nd_region->nd_set; + + if (a != &dev_attr_set_cookie.attr) + return a->mode; + + if (is_nd_pmem(dev) && nd_set) + return a->mode; + + return 0; +} + struct attribute_group nd_region_attribute_group = { .attrs = nd_region_attributes, + .is_visible = region_visible, }; EXPORT_SYMBOL_GPL(nd_region_attribute_group); +/* + * Upon successful probe/remove, take/release a reference on the + * associated interleave set (if present) + */ +static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus, + struct device *dev, bool probe) +{ + if (is_nd_pmem(dev) || is_nd_blk(dev)) { + struct nd_region *nd_region = to_nd_region(dev); + int i; + + for (i = 0; i < nd_region->ndr_mappings; i++) { + struct nd_mapping *nd_mapping = &nd_region->mapping[i]; + struct nvdimm *nvdimm = nd_mapping->nvdimm; + + if (probe) + atomic_inc(&nvdimm->busy); + else + atomic_dec(&nvdimm->busy); + } + } +} + +void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev) +{ + nd_region_notify_driver_action(nvdimm_bus, dev, true); +} + +void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev) +{ + nd_region_notify_driver_action(nvdimm_bus, dev, false); +} + static ssize_t mappingN(struct device *dev, char *buf, int n) { struct nd_region *nd_region = to_nd_region(dev); @@ -322,6 +390,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus, } nd_region->ndr_mappings = ndr_desc->num_mappings; nd_region->provider_data = ndr_desc->provider_data; + nd_region->nd_set = ndr_desc->nd_set; dev = &nd_region->dev; dev_set_name(dev, "region%d", nd_region->id); dev->parent = &nvdimm_bus->dev; -- cgit v1.1