10 files changed, 100 insertions, 3 deletions

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 07d630e9f4ae..1f6f1b1a54f4 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -668,6 +668,20 @@ static ssize_t serial_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(serial);
 
+static ssize_t flags_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        u16 flags = to_nfit_memdev(dev)->flags;
+
+        return sprintf(buf, "%s%s%s%s%s\n",
+                        flags & ACPI_NFIT_MEM_SAVE_FAILED ? "save " : "",
+                        flags & ACPI_NFIT_MEM_RESTORE_FAILED ? "restore " : "",
+                        flags & ACPI_NFIT_MEM_FLUSH_FAILED ? "flush " : "",
+                        flags & ACPI_NFIT_MEM_ARMED ? "arm " : "",
+                        flags & ACPI_NFIT_MEM_HEALTH_OBSERVED ? "smart " : "");
+}
+static DEVICE_ATTR_RO(flags);
+
 static struct attribute *acpi_nfit_dimm_attributes[] = {
         &dev_attr_handle.attr,
         &dev_attr_phys_id.attr,
@@ -676,6 +690,7 @@ static struct attribute *acpi_nfit_dimm_attributes[] = {
         &dev_attr_format.attr,
         &dev_attr_serial.attr,
         &dev_attr_rev_id.attr,
+        &dev_attr_flags.attr,
         NULL,
 };
 
@@ -768,6 +783,7 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
                 struct nvdimm *nvdimm;
                 unsigned long flags = 0;
                 u32 device_handle;
+                u16 mem_flags;
                 int rc;
 
                 device_handle = __to_nfit_memdev(nfit_mem)->device_handle;
@@ -785,6 +801,10 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
                 if (nfit_mem->bdw && nfit_mem->memdev_pmem)
                         flags |= NDD_ALIASING;
 
+                mem_flags = __to_nfit_memdev(nfit_mem)->flags;
+                if (mem_flags & ACPI_NFIT_MEM_ARMED)
+                        flags |= NDD_UNARMED;
+
                 rc = acpi_nfit_add_dimm(acpi_desc, nfit_mem, device_handle);
                 if (rc)
                         continue;
@@ -797,6 +817,17 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 
                 nfit_mem->nvdimm = nvdimm;
                 dimm_count++;
+
+                if ((mem_flags & ACPI_NFIT_MEM_FAILED_MASK) == 0)
+                        continue;
+
+                dev_info(acpi_desc->dev, "%s: failed: %s%s%s%s\n",
+                                nvdimm_name(nvdimm),
+                        mem_flags & ACPI_NFIT_MEM_SAVE_FAILED ? "save " : "",
+                        mem_flags & ACPI_NFIT_MEM_RESTORE_FAILED ? "restore " : "",
+                        mem_flags & ACPI_NFIT_MEM_FLUSH_FAILED ? "flush " : "",
+                        mem_flags & ACPI_NFIT_MEM_ARMED ? "arm " : "");
+
         }
 
         return nvdimm_bus_check_dimm_count(acpi_desc->nvdimm_bus, dimm_count);
diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index c62fffea8423..81f2e8c5a79c 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -22,6 +22,9 @@
 
 #define UUID_NFIT_BUS "2f10e7a4-9e91-11e4-89d3-123b93f75cba"
 #define UUID_NFIT_DIMM "4309ac30-0d11-11e4-9191-0800200c9a66"
+#define ACPI_NFIT_MEM_FAILED_MASK (ACPI_NFIT_MEM_SAVE_FAILED \
+                | ACPI_NFIT_MEM_RESTORE_FAILED | ACPI_NFIT_MEM_FLUSH_FAILED \
+                | ACPI_NFIT_MEM_ARMED)
 
 enum nfit_uuids {
         NFIT_SPA_VOLATILE,
diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index 96ef38ceeceb..4f97b248c236 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -232,6 +232,7 @@ static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
 
 static const struct block_device_operations nd_blk_fops = {
         .owner = THIS_MODULE,
+        .revalidate_disk = nvdimm_revalidate_disk,
 };
 
 static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
@@ -283,6 +284,7 @@ static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
         }
 
         set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
+        revalidate_disk(disk);
         return 0;
 }
 
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index c02065aed03d..411c7b2bb37a 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1245,6 +1245,7 @@ static const struct block_device_operations btt_fops = {
         .owner =                THIS_MODULE,
         .rw_page =              btt_rw_page,
         .getgeo =               btt_getgeo,
+        .revalidate_disk =      nvdimm_revalidate_disk,
 };
 
 static int btt_blk_init(struct btt *btt)
@@ -1292,6 +1293,7 @@ static int btt_blk_init(struct btt *btt)
                 }
         }
         set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
+        revalidate_disk(btt->btt_disk);
 
         return 0;
 }
@@ -1346,7 +1348,11 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
                 goto out_free;
         }
 
-        if (btt->init_state != INIT_READY) {
+        if (btt->init_state != INIT_READY && nd_region->ro) {
+                dev_info(dev, "%s is read-only, unable to init btt metadata\n",
+                                dev_name(&nd_region->dev));
+                goto out_free;
+        } else if (btt->init_state != INIT_READY) {
                 btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
                         ((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
                 dev_dbg(dev, "init: %d arenas for %llu rawsize\n",
@@ -1361,7 +1367,7 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
                 ret = btt_meta_init(btt);
                 if (ret) {
                         dev_err(dev, "init: error in meta_init: %d\n", ret);
-                        return NULL;
+                        goto out_free;
                 }
         }
 
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index dd12f38397db..ec59f1f26d95 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -227,6 +227,24 @@ int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 }
 EXPORT_SYMBOL(__nd_driver_register);
 
+int nvdimm_revalidate_disk(struct gendisk *disk)
+{
+        struct device *dev = disk->driverfs_dev;
+        struct nd_region *nd_region = to_nd_region(dev->parent);
+        const char *pol = nd_region->ro ? "only" : "write";
+
+        if (nd_region->ro == get_disk_ro(disk))
+                return 0;
+
+        dev_info(dev, "%s read-%s, marking %s read-%s\n",
+                        dev_name(&nd_region->dev), pol, disk->disk_name, pol);
+        set_disk_ro(disk, nd_region->ro);
+
+        return 0;
+
+}
+EXPORT_SYMBOL(nvdimm_revalidate_disk);
+
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
                 char *buf)
 {
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 4614b00542d1..48b09a210689 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -97,7 +97,7 @@ struct nd_region {
         u16 ndr_mappings;
         u64 ndr_size;
         u64 ndr_start;
-        int id, num_lanes;
+        int id, num_lanes, ro;
         void *provider_data;
         struct nd_interleave_set *nd_set;
         struct nd_percpu_lane __percpu *lane;
@@ -189,6 +189,7 @@ u64 nd_region_interleave_set_cookie(struct nd_region *nd_region);
 void nvdimm_bus_lock(struct device *dev);
 void nvdimm_bus_unlock(struct device *dev);
 bool is_nvdimm_bus_locked(struct device *dev);
+int nvdimm_revalidate_disk(struct gendisk *disk);
 void nvdimm_drvdata_release(struct kref *kref);
 void put_ndd(struct nvdimm_drvdata *ndd);
 int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index a9709db0704c..42b766f33e59 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -104,6 +104,7 @@ static const struct block_device_operations pmem_fops = {
         .owner =                THIS_MODULE,
         .rw_page =              pmem_rw_page,
         .direct_access =        pmem_direct_access,
+        .revalidate_disk =      nvdimm_revalidate_disk,
 };
 
 static struct pmem_device *pmem_alloc(struct device *dev,
@@ -178,6 +179,7 @@ static int pmem_attach_disk(struct nd_namespace_common *ndns,
         pmem->pmem_disk = disk;
 
         add_disk(disk);
+        revalidate_disk(disk);
 
         return 0;
 }
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 2cfb3f74bcbf..482ee3e4e04a 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -345,11 +345,35 @@ static ssize_t btt_seed_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(btt_seed);
 
+static ssize_t read_only_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct nd_region *nd_region = to_nd_region(dev);
+
+        return sprintf(buf, "%d\n", nd_region->ro);
+}
+
+static ssize_t read_only_store(struct device *dev,
+                struct device_attribute *attr, const char *buf, size_t len)
+{
+        bool ro;
+        int rc = strtobool(buf, &ro);
+        struct nd_region *nd_region = to_nd_region(dev);
+
+        if (rc)
+                return rc;
+
+        nd_region->ro = ro;
+        return len;
+}
+static DEVICE_ATTR_RW(read_only);
+
 static struct attribute *nd_region_attributes[] = {
         &dev_attr_size.attr,
         &dev_attr_nstype.attr,
         &dev_attr_mappings.attr,
         &dev_attr_btt_seed.attr,
+        &dev_attr_read_only.attr,
         &dev_attr_set_cookie.attr,
         &dev_attr_available_size.attr,
         &dev_attr_namespace_seed.attr,
@@ -641,6 +665,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
         struct device *dev;
         void *region_buf;
         unsigned int i;
+        int ro = 0;
 
         for (i = 0; i < ndr_desc->num_mappings; i++) {
                 struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
@@ -652,6 +677,9 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 
                         return NULL;
                 }
+
+                if (nvdimm->flags & NDD_UNARMED)
+                        ro = 1;
         }
 
         if (dev_type == &nd_blk_device_type) {
@@ -707,6 +735,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
         nd_region->provider_data = ndr_desc->provider_data;
         nd_region->nd_set = ndr_desc->nd_set;
         nd_region->num_lanes = ndr_desc->num_lanes;
+        nd_region->ro = ro;
         ida_init(&nd_region->ns_ida);
         ida_init(&nd_region->btt_ida);
         dev = &nd_region->dev;
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 7fc1b25bdb5d..dc799a29ed1a 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -21,6 +21,8 @@
 enum {
         /* when a dimm supports both PMEM and BLK access a label is required */
         NDD_ALIASING = 1 << 0,
+        /* unarmed memory devices may not persist writes */
+        NDD_UNARMED = 1 << 1,
 
         /* need to set a limit somewhere, but yes, this is likely overkill */
         ND_IOCTL_MAX_BUFLEN = SZ_4M,
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index 7a4a5a5edbe4..4b69b8368de0 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -874,6 +874,9 @@ static void nfit_test1_setup(struct nfit_test *t)
         memdev->address = 0;
         memdev->interleave_index = 0;
         memdev->interleave_ways = 1;
+        memdev->flags = ACPI_NFIT_MEM_SAVE_FAILED | ACPI_NFIT_MEM_RESTORE_FAILED
+                | ACPI_NFIT_MEM_FLUSH_FAILED | ACPI_NFIT_MEM_HEALTH_OBSERVED
+                | ACPI_NFIT_MEM_ARMED;
 
         offset += sizeof(*memdev);
         /* dcr-descriptor0 */