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 <neilb@suse.de>
Cc: <linux-acpi@vger.kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Robert Moore <robert.moore@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index ce290748fe365bf22c5a74cf621ecd99387d9310..35af6f7f0abd696c6076849930d16cee22cf27d5 100644 (file)
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -16,6 +16,7 @@
 #include <linux/ndctl.h>
 #include <linux/list.h>
 #include <linux/acpi.h>
+#include <linux/sort.h>
 #include "nfit.h"
 
 static bool force_enable_dimms;
@@ -785,6 +786,91 @@ static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
        NULL,
 };
 
+/* enough info to uniquely specify an interleave set */
+struct nfit_set_info {
+       struct nfit_set_info_map {
+               u64 region_offset;
+               u32 serial_number;
+               u32 pad;
+       } mapping[0];
+};
+
+static size_t sizeof_nfit_set_info(int num_mappings)
+{
+       return sizeof(struct nfit_set_info)
+               + num_mappings * sizeof(struct nfit_set_info_map);
+}
+
+static int cmp_map(const void *m0, const void *m1)
+{
+       const struct nfit_set_info_map *map0 = m0;
+       const struct nfit_set_info_map *map1 = m1;
+
+       return memcmp(&map0->region_offset, &map1->region_offset,
+                       sizeof(u64));
+}
+
+/* Retrieve the nth entry referencing this spa */
+static struct acpi_nfit_memory_map *memdev_from_spa(
+               struct acpi_nfit_desc *acpi_desc, u16 range_index, int n)
+{
+       struct nfit_memdev *nfit_memdev;
+
+       list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list)
+               if (nfit_memdev->memdev->range_index == range_index)
+                       if (n-- == 0)
+                               return nfit_memdev->memdev;
+       return NULL;
+}
+
+static int acpi_nfit_init_interleave_set(struct acpi_nfit_desc *acpi_desc,
+               struct nd_region_desc *ndr_desc,
+               struct acpi_nfit_system_address *spa)
+{
+       int i, spa_type = nfit_spa_type(spa);
+       struct device *dev = acpi_desc->dev;
+       struct nd_interleave_set *nd_set;
+       u16 nr = ndr_desc->num_mappings;
+       struct nfit_set_info *info;
+
+       if (spa_type == NFIT_SPA_PM || spa_type == NFIT_SPA_VOLATILE)
+               /* pass */;
+       else
+               return 0;
+
+       nd_set = devm_kzalloc(dev, sizeof(*nd_set), GFP_KERNEL);
+       if (!nd_set)
+               return -ENOMEM;
+
+       info = devm_kzalloc(dev, sizeof_nfit_set_info(nr), GFP_KERNEL);
+       if (!info)
+               return -ENOMEM;
+       for (i = 0; i < nr; i++) {
+               struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
+               struct nfit_set_info_map *map = &info->mapping[i];
+               struct nvdimm *nvdimm = nd_mapping->nvdimm;
+               struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+               struct acpi_nfit_memory_map *memdev = memdev_from_spa(acpi_desc,
+                               spa->range_index, i);
+
+               if (!memdev || !nfit_mem->dcr) {
+                       dev_err(dev, "%s: failed to find DCR\n", __func__);
+                       return -ENODEV;
+               }
+
+               map->region_offset = memdev->region_offset;
+               map->serial_number = nfit_mem->dcr->serial_number;
+       }
+
+       sort(&info->mapping[0], nr, sizeof(struct nfit_set_info_map),
+                       cmp_map, NULL);
+       nd_set->cookie = nd_fletcher64(info, sizeof_nfit_set_info(nr), 0);
+       ndr_desc->nd_set = nd_set;
+       devm_kfree(dev, info);
+
+       return 0;
+}
+
 static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
                struct nd_mapping *nd_mapping, struct nd_region_desc *ndr_desc,
                struct acpi_nfit_memory_map *memdev,
@@ -838,7 +924,7 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
        struct nd_region_desc ndr_desc;
        struct nvdimm_bus *nvdimm_bus;
        struct resource res;
-       int count = 0;
+       int count = 0, rc;
 
        if (spa->range_index == 0) {
                dev_dbg(acpi_desc->dev, "%s: detected invalid spa index\n",
@@ -857,7 +943,6 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
        list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
                struct acpi_nfit_memory_map *memdev = nfit_memdev->memdev;
                struct nd_mapping *nd_mapping;
-               int rc;
 
                if (memdev->range_index != spa->range_index)
                        continue;
@@ -875,6 +960,10 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 
        ndr_desc.nd_mapping = nd_mappings;
        ndr_desc.num_mappings = count;
+       rc = acpi_nfit_init_interleave_set(acpi_desc, &ndr_desc, spa);
+       if (rc)
+               return rc;
+
        nvdimm_bus = acpi_desc->nvdimm_bus;
        if (nfit_spa_type(spa) == NFIT_SPA_PM) {
                if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 4b77665a6cc8fa491a87ed6c0b6a769c02a697d3..ffb43cada625c16d9a51394191171aa8f385d1f3 100644 (file)
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -68,6 +68,21 @@ static struct module *to_bus_provider(struct device *dev)
        return NULL;
 }
 
+static void nvdimm_bus_probe_start(struct nvdimm_bus *nvdimm_bus)
+{
+       nvdimm_bus_lock(&nvdimm_bus->dev);
+       nvdimm_bus->probe_active++;
+       nvdimm_bus_unlock(&nvdimm_bus->dev);
+}
+
+static void nvdimm_bus_probe_end(struct nvdimm_bus *nvdimm_bus)
+{
+       nvdimm_bus_lock(&nvdimm_bus->dev);
+       if (--nvdimm_bus->probe_active == 0)
+               wake_up(&nvdimm_bus->probe_wait);
+       nvdimm_bus_unlock(&nvdimm_bus->dev);
+}
+
 static int nvdimm_bus_probe(struct device *dev)
 {
        struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
@@ -78,7 +93,12 @@ static int nvdimm_bus_probe(struct device *dev)
        if (!try_module_get(provider))
                return -ENXIO;
 
+       nvdimm_bus_probe_start(nvdimm_bus);
        rc = nd_drv->probe(dev);
+       if (rc == 0)
+               nd_region_probe_success(nvdimm_bus, dev);
+       nvdimm_bus_probe_end(nvdimm_bus);
+
        dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
                        dev_name(dev), rc);
        if (rc != 0)
@@ -94,6 +114,8 @@ static int nvdimm_bus_remove(struct device *dev)
        int rc;
 
        rc = nd_drv->remove(dev);
+       nd_region_disable(nvdimm_bus, dev);
+
        dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
                        dev_name(dev), rc);
        module_put(provider);
@@ -359,6 +381,34 @@ u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
 }
 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
 
+static void wait_nvdimm_bus_probe_idle(struct nvdimm_bus *nvdimm_bus)
+{
+       do {
+               if (nvdimm_bus->probe_active == 0)
+                       break;
+               nvdimm_bus_unlock(&nvdimm_bus->dev);
+               wait_event(nvdimm_bus->probe_wait,
+                               nvdimm_bus->probe_active == 0);
+               nvdimm_bus_lock(&nvdimm_bus->dev);
+       } while (true);
+}
+
+/* set_config requires an idle interleave set */
+static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd)
+{
+       struct nvdimm_bus *nvdimm_bus;
+
+       if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
+               return 0;
+
+       nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
+       wait_nvdimm_bus_probe_idle(nvdimm_bus);
+
+       if (atomic_read(&nvdimm->busy))
+               return -EBUSY;
+       return 0;
+}
+
 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
                int read_only, unsigned int ioctl_cmd, unsigned long arg)
 {
@@ -469,11 +519,18 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
                goto out;
        }
 
+       nvdimm_bus_lock(&nvdimm_bus->dev);
+       rc = nd_cmd_clear_to_send(nvdimm, cmd);
+       if (rc)
+               goto out_unlock;
+
        rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
        if (rc < 0)
-               goto out;
+               goto out_unlock;
        if (copy_to_user(p, buf, buf_len))
                rc = -EFAULT;
+ out_unlock:
+       nvdimm_bus_unlock(&nvdimm_bus->dev);
  out:
        vfree(buf);
        return rc;

diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 1b6b15d11f54ad0901f2e142f204ff41510282ee..7806eaaf470771c95d7b72f4db21d8e71bed549c 100644 (file)
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -54,6 +54,22 @@ bool is_nvdimm_bus_locked(struct device *dev)
 }
 EXPORT_SYMBOL(is_nvdimm_bus_locked);
 
+u64 nd_fletcher64(void *addr, size_t len, bool le)
+{
+       u32 *buf = addr;
+       u32 lo32 = 0;
+       u64 hi32 = 0;
+       int i;
+
+       for (i = 0; i < len / sizeof(u32); i++) {
+               lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
+               hi32 += lo32;
+       }
+
+       return hi32 << 32 | lo32;
+}
+EXPORT_SYMBOL_GPL(nd_fletcher64);
+
 static void nvdimm_bus_release(struct device *dev)
 {
        struct nvdimm_bus *nvdimm_bus;
@@ -175,6 +191,7 @@ struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
        if (!nvdimm_bus)
                return NULL;
        INIT_LIST_HEAD(&nvdimm_bus->list);
+       init_waitqueue_head(&nvdimm_bus->probe_wait);
        nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
        mutex_init(&nvdimm_bus->reconfig_mutex);
        if (nvdimm_bus->id < 0) {

diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index b3ae86f2e1dad80228dcfd7593ef95b5cda6e24a..bdf8241b6525cf0d87b395dc56ec1763a6e9e072 100644 (file)
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -185,7 +185,24 @@ static ssize_t commands_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(commands);
 
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+               char *buf)
+{
+       struct nvdimm *nvdimm = to_nvdimm(dev);
+
+       /*
+        * The state may be in the process of changing, userspace should
+        * quiesce probing if it wants a static answer
+        */
+       nvdimm_bus_lock(dev);
+       nvdimm_bus_unlock(dev);
+       return sprintf(buf, "%s\n", atomic_read(&nvdimm->busy)
+                       ? "active" : "idle");
+}
+static DEVICE_ATTR_RO(state);
+
 static struct attribute *nvdimm_attributes[] = {
+       &dev_attr_state.attr,
        &dev_attr_commands.attr,
        NULL,
 };
@@ -213,7 +230,7 @@ struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus, void *provider_data,
        nvdimm->provider_data = provider_data;
        nvdimm->flags = flags;
        nvdimm->dsm_mask = dsm_mask;
-
+       atomic_set(&nvdimm->busy, 0);
        dev = &nvdimm->dev;
        dev_set_name(dev, "nmem%d", nvdimm->id);
        dev->parent = &nvdimm_bus->dev;

diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 0e9b41fd25461dd8db40fc56b00e8267f057e126..6a4b2c066ee7ead65589bee1b6f04ae196ce8f26 100644 (file)
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -14,6 +14,9 @@
 #define __ND_CORE_H__
 #include <linux/libnvdimm.h>
 #include <linux/device.h>
+#include <linux/libnvdimm.h>
+#include <linux/sizes.h>
+#include <linux/mutex.h>
 
 extern struct list_head nvdimm_bus_list;
 extern struct mutex nvdimm_bus_list_mutex;
@@ -21,10 +24,11 @@ extern int nvdimm_major;
 
 struct nvdimm_bus {
        struct nvdimm_bus_descriptor *nd_desc;
+       wait_queue_head_t probe_wait;
        struct module *module;
        struct list_head list;
        struct device dev;
-       int id;
+       int id, probe_active;
        struct mutex reconfig_mutex;
 };
 
@@ -33,6 +37,7 @@ struct nvdimm {
        void *provider_data;
        unsigned long *dsm_mask;
        struct device dev;
+       atomic_t busy;
        int id;
 };
 
@@ -42,10 +47,13 @@ bool is_nd_pmem(struct device *dev);
 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev);
 int __init nvdimm_bus_init(void);
 void nvdimm_bus_exit(void);
+void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev);
+void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev);
 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus);
 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);
 void nd_synchronize(void);
 int nvdimm_bus_register_dimms(struct nvdimm_bus *nvdimm_bus);
 int nvdimm_bus_register_regions(struct nvdimm_bus *nvdimm_bus);
+int nvdimm_bus_init_interleave_sets(struct nvdimm_bus *nvdimm_bus);
 int nd_match_dimm(struct device *dev, void *data);
 #endif /* __ND_CORE_H__ */

diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index bc5a08e36a25049b52c22c7bbd09796816fd58d7..0285e4588b0350c8e50ba1a4462f84f50789c969 100644 (file)
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -35,6 +35,7 @@ struct nd_region {
        u64 ndr_start;
        int id;
        void *provider_data;
+       struct nd_interleave_set *nd_set;
        struct nd_mapping mapping[0];
 };
 

diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index b5c5b9095b28e34ccc3b8db602e09e91a07d0c8e..1571424578f0edb290194507af46b9b15000dc47 100644 (file)
--- 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 <linux/scatterlist.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/sort.h>
 #include <linux/io.h>
 #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;

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 37f966aff3861aa30bd8c9120cf643d5b06e7329..1b627b109360610841fcd8aeaab26aaa2d79dd0f 100644 (file)
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -61,11 +61,16 @@ struct nd_cmd_desc {
        int out_sizes[ND_CMD_MAX_ELEM];
 };
 
+struct nd_interleave_set {
+       u64 cookie;
+};
+
 struct nd_region_desc {
        struct resource *res;
        struct nd_mapping *nd_mapping;
        u16 num_mappings;
        const struct attribute_group **attr_groups;
+       struct nd_interleave_set *nd_set;
        void *provider_data;
 };
 
@@ -101,4 +106,5 @@ struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
                struct nd_region_desc *ndr_desc);
 struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
                struct nd_region_desc *ndr_desc);
+u64 nd_fletcher64(void *addr, size_t len, bool le);
 #endif /* __LIBNVDIMM_H__ */