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libnvdimm: support for legacy (non-aliasing) nvdimms
authorDan Williams <dan.j.williams@intel.com>
Sun, 31 May 2015 19:02:11 +0000 (15:02 -0400)
committerDan Williams <dan.j.williams@intel.com>
Thu, 25 Jun 2015 01:24:10 +0000 (21:24 -0400)
The libnvdimm region driver is an intermediary driver that translates
non-volatile "region"s into "namespace" sub-devices that are surfaced by
persistent memory block-device drivers (PMEM and BLK).

ACPI 6 introduces the concept that a given nvdimm may simultaneously
offer multiple access modes to its media through direct PMEM load/store
access, or windowed BLK mode.  Existing nvdimms mostly implement a PMEM
interface, some offer a BLK-like mode, but never both as ACPI 6 defines.
If an nvdimm is single interfaced, then there is no need for dimm
metadata labels.  For these devices we can take the region boundaries
directly to create a child namespace device (nd_namespace_io).

Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
13 files changed:
drivers/acpi/nfit.c
drivers/nvdimm/Makefile
drivers/nvdimm/bus.c
drivers/nvdimm/core.c
drivers/nvdimm/dimm.c
drivers/nvdimm/namespace_devs.c [new file with mode: 0644]
drivers/nvdimm/nd-core.h
drivers/nvdimm/nd.h
drivers/nvdimm/region.c [new file with mode: 0644]
drivers/nvdimm/region_devs.c
include/linux/libnvdimm.h
include/linux/nd.h
include/uapi/linux/ndctl.h

index 068f69d..ce29074 100644 (file)
@@ -780,6 +780,7 @@ static struct attribute_group acpi_nfit_region_attribute_group = {
 static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
        &nd_region_attribute_group,
        &nd_mapping_attribute_group,
+       &nd_device_attribute_group,
        &acpi_nfit_region_attribute_group,
        NULL,
 };
index 88afd0d..af5e276 100644 (file)
@@ -5,3 +5,5 @@ libnvdimm-y += bus.o
 libnvdimm-y += dimm_devs.o
 libnvdimm-y += dimm.o
 libnvdimm-y += region_devs.o
+libnvdimm-y += region.o
+libnvdimm-y += namespace_devs.o
index a0308f1..4b77665 100644 (file)
@@ -13,6 +13,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/vmalloc.h>
 #include <linux/uaccess.h>
+#include <linux/module.h>
 #include <linux/fcntl.h>
 #include <linux/async.h>
 #include <linux/ndctl.h>
@@ -33,6 +34,12 @@ static int to_nd_device_type(struct device *dev)
 {
        if (is_nvdimm(dev))
                return ND_DEVICE_DIMM;
+       else if (is_nd_pmem(dev))
+               return ND_DEVICE_REGION_PMEM;
+       else if (is_nd_blk(dev))
+               return ND_DEVICE_REGION_BLK;
+       else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
+               return nd_region_to_nstype(to_nd_region(dev->parent));
 
        return 0;
 }
@@ -50,27 +57,46 @@ static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
        return test_bit(to_nd_device_type(dev), &nd_drv->type);
 }
 
+static struct module *to_bus_provider(struct device *dev)
+{
+       /* pin bus providers while regions are enabled */
+       if (is_nd_pmem(dev) || is_nd_blk(dev)) {
+               struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+               return nvdimm_bus->module;
+       }
+       return NULL;
+}
+
 static int nvdimm_bus_probe(struct device *dev)
 {
        struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
+       struct module *provider = to_bus_provider(dev);
        struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
        int rc;
 
+       if (!try_module_get(provider))
+               return -ENXIO;
+
        rc = nd_drv->probe(dev);
        dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
                        dev_name(dev), rc);
+       if (rc != 0)
+               module_put(provider);
        return rc;
 }
 
 static int nvdimm_bus_remove(struct device *dev)
 {
        struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
+       struct module *provider = to_bus_provider(dev);
        struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
        int rc;
 
        rc = nd_drv->remove(dev);
        dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
                        dev_name(dev), rc);
+       module_put(provider);
        return rc;
 }
 
index 50ab880..1b6b15d 100644 (file)
@@ -24,6 +24,36 @@ LIST_HEAD(nvdimm_bus_list);
 DEFINE_MUTEX(nvdimm_bus_list_mutex);
 static DEFINE_IDA(nd_ida);
 
+void nvdimm_bus_lock(struct device *dev)
+{
+       struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+       if (!nvdimm_bus)
+               return;
+       mutex_lock(&nvdimm_bus->reconfig_mutex);
+}
+EXPORT_SYMBOL(nvdimm_bus_lock);
+
+void nvdimm_bus_unlock(struct device *dev)
+{
+       struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+       if (!nvdimm_bus)
+               return;
+       mutex_unlock(&nvdimm_bus->reconfig_mutex);
+}
+EXPORT_SYMBOL(nvdimm_bus_unlock);
+
+bool is_nvdimm_bus_locked(struct device *dev)
+{
+       struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+       if (!nvdimm_bus)
+               return false;
+       return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
+}
+EXPORT_SYMBOL(is_nvdimm_bus_locked);
+
 static void nvdimm_bus_release(struct device *dev)
 {
        struct nvdimm_bus *nvdimm_bus;
@@ -135,8 +165,8 @@ struct attribute_group nvdimm_bus_attribute_group = {
 };
 EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
 
-struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
-               struct nvdimm_bus_descriptor *nd_desc)
+struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
+               struct nvdimm_bus_descriptor *nd_desc, struct module *module)
 {
        struct nvdimm_bus *nvdimm_bus;
        int rc;
@@ -146,11 +176,13 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
                return NULL;
        INIT_LIST_HEAD(&nvdimm_bus->list);
        nvdimm_bus->id = ida_simple_get(&nd_ida, 0, 0, GFP_KERNEL);
+       mutex_init(&nvdimm_bus->reconfig_mutex);
        if (nvdimm_bus->id < 0) {
                kfree(nvdimm_bus);
                return NULL;
        }
        nvdimm_bus->nd_desc = nd_desc;
+       nvdimm_bus->module = module;
        nvdimm_bus->dev.parent = parent;
        nvdimm_bus->dev.release = nvdimm_bus_release;
        nvdimm_bus->dev.groups = nd_desc->attr_groups;
@@ -174,7 +206,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
        put_device(&nvdimm_bus->dev);
        return NULL;
 }
-EXPORT_SYMBOL_GPL(nvdimm_bus_register);
+EXPORT_SYMBOL_GPL(__nvdimm_bus_register);
 
 static int child_unregister(struct device *dev, void *data)
 {
@@ -218,7 +250,12 @@ static __init int libnvdimm_init(void)
        rc = nvdimm_init();
        if (rc)
                goto err_dimm;
+       rc = nd_region_init();
+       if (rc)
+               goto err_region;
        return 0;
+ err_region:
+       nvdimm_exit();
  err_dimm:
        nvdimm_bus_exit();
        return rc;
@@ -227,6 +264,7 @@ static __init int libnvdimm_init(void)
 static __exit void libnvdimm_exit(void)
 {
        WARN_ON(!list_empty(&nvdimm_bus_list));
+       nd_region_exit();
        nvdimm_exit();
        nvdimm_bus_exit();
 }
index 28001a6..eb20fc2 100644 (file)
@@ -84,7 +84,7 @@ int __init nvdimm_init(void)
        return nd_driver_register(&nvdimm_driver);
 }
 
-void __exit nvdimm_exit(void)
+void nvdimm_exit(void)
 {
        driver_unregister(&nvdimm_driver.drv);
 }
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
new file mode 100644 (file)
index 0000000..4f653d1
--- /dev/null
@@ -0,0 +1,111 @@
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/nd.h>
+#include "nd.h"
+
+static void namespace_io_release(struct device *dev)
+{
+       struct nd_namespace_io *nsio = to_nd_namespace_io(dev);
+
+       kfree(nsio);
+}
+
+static struct device_type namespace_io_device_type = {
+       .name = "nd_namespace_io",
+       .release = namespace_io_release,
+};
+
+static ssize_t nstype_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_region *nd_region = to_nd_region(dev->parent);
+
+       return sprintf(buf, "%d\n", nd_region_to_nstype(nd_region));
+}
+static DEVICE_ATTR_RO(nstype);
+
+static struct attribute *nd_namespace_attributes[] = {
+       &dev_attr_nstype.attr,
+       NULL,
+};
+
+static struct attribute_group nd_namespace_attribute_group = {
+       .attrs = nd_namespace_attributes,
+};
+
+static const struct attribute_group *nd_namespace_attribute_groups[] = {
+       &nd_device_attribute_group,
+       &nd_namespace_attribute_group,
+       NULL,
+};
+
+static struct device **create_namespace_io(struct nd_region *nd_region)
+{
+       struct nd_namespace_io *nsio;
+       struct device *dev, **devs;
+       struct resource *res;
+
+       nsio = kzalloc(sizeof(*nsio), GFP_KERNEL);
+       if (!nsio)
+               return NULL;
+
+       devs = kcalloc(2, sizeof(struct device *), GFP_KERNEL);
+       if (!devs) {
+               kfree(nsio);
+               return NULL;
+       }
+
+       dev = &nsio->dev;
+       dev->type = &namespace_io_device_type;
+       dev->parent = &nd_region->dev;
+       res = &nsio->res;
+       res->name = dev_name(&nd_region->dev);
+       res->flags = IORESOURCE_MEM;
+       res->start = nd_region->ndr_start;
+       res->end = res->start + nd_region->ndr_size - 1;
+
+       devs[0] = dev;
+       return devs;
+}
+
+int nd_region_register_namespaces(struct nd_region *nd_region, int *err)
+{
+       struct device **devs = NULL;
+       int i;
+
+       *err = 0;
+       switch (nd_region_to_nstype(nd_region)) {
+       case ND_DEVICE_NAMESPACE_IO:
+               devs = create_namespace_io(nd_region);
+               break;
+       default:
+               break;
+       }
+
+       if (!devs)
+               return -ENODEV;
+
+       for (i = 0; devs[i]; i++) {
+               struct device *dev = devs[i];
+
+               dev_set_name(dev, "namespace%d.%d", nd_region->id, i);
+               dev->groups = nd_namespace_attribute_groups;
+               nd_device_register(dev);
+       }
+       kfree(devs);
+
+       return i;
+}
index 1d760bf..0e9b41f 100644 (file)
@@ -21,9 +21,11 @@ extern int nvdimm_major;
 
 struct nvdimm_bus {
        struct nvdimm_bus_descriptor *nd_desc;
+       struct module *module;
        struct list_head list;
        struct device dev;
        int id;
+       struct mutex reconfig_mutex;
 };
 
 struct nvdimm {
@@ -34,6 +36,9 @@ struct nvdimm {
        int id;
 };
 
+bool is_nvdimm(struct device *dev);
+bool is_nd_blk(struct device *dev);
+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);
@@ -43,5 +48,4 @@ 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 nd_match_dimm(struct device *dev, void *data);
-bool is_nvdimm(struct device *dev);
 #endif /* __ND_CORE_H__ */
index ea0cca3..bc5a08e 100644 (file)
@@ -23,6 +23,11 @@ struct nvdimm_drvdata {
        void *data;
 };
 
+struct nd_region_namespaces {
+       int count;
+       int active;
+};
+
 struct nd_region {
        struct device dev;
        u16 ndr_mappings;
@@ -41,7 +46,15 @@ enum nd_async_mode {
 void nd_device_register(struct device *dev);
 void nd_device_unregister(struct device *dev, enum nd_async_mode mode);
 int __init nvdimm_init(void);
+int __init nd_region_init(void);
 void nvdimm_exit(void);
+void nd_region_exit(void);
 int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd);
 int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
+struct nd_region *to_nd_region(struct device *dev);
+int nd_region_to_nstype(struct nd_region *nd_region);
+int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
+void nvdimm_bus_lock(struct device *dev);
+void nvdimm_bus_unlock(struct device *dev);
+bool is_nvdimm_bus_locked(struct device *dev);
 #endif /* __ND_H__ */
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
new file mode 100644 (file)
index 0000000..ade3dba
--- /dev/null
@@ -0,0 +1,93 @@
+/*
+ * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/nd.h>
+#include "nd.h"
+
+static int nd_region_probe(struct device *dev)
+{
+       int err;
+       struct nd_region_namespaces *num_ns;
+       struct nd_region *nd_region = to_nd_region(dev);
+       int rc = nd_region_register_namespaces(nd_region, &err);
+
+       num_ns = devm_kzalloc(dev, sizeof(*num_ns), GFP_KERNEL);
+       if (!num_ns)
+               return -ENOMEM;
+
+       if (rc < 0)
+               return rc;
+
+       num_ns->active = rc;
+       num_ns->count = rc + err;
+       dev_set_drvdata(dev, num_ns);
+
+       if (err == 0)
+               return 0;
+
+       if (rc == err)
+               return -ENODEV;
+
+       /*
+        * Given multiple namespaces per region, we do not want to
+        * disable all the successfully registered peer namespaces upon
+        * a single registration failure.  If userspace is missing a
+        * namespace that it expects it can disable/re-enable the region
+        * to retry discovery after correcting the failure.
+        * <regionX>/namespaces returns the current
+        * "<async-registered>/<total>" namespace count.
+        */
+       dev_err(dev, "failed to register %d namespace%s, continuing...\n",
+                       err, err == 1 ? "" : "s");
+       return 0;
+}
+
+static int child_unregister(struct device *dev, void *data)
+{
+       nd_device_unregister(dev, ND_SYNC);
+       return 0;
+}
+
+static int nd_region_remove(struct device *dev)
+{
+       /* flush attribute readers and disable */
+       nvdimm_bus_lock(dev);
+       dev_set_drvdata(dev, NULL);
+       nvdimm_bus_unlock(dev);
+
+       device_for_each_child(dev, NULL, child_unregister);
+       return 0;
+}
+
+static struct nd_device_driver nd_region_driver = {
+       .probe = nd_region_probe,
+       .remove = nd_region_remove,
+       .drv = {
+               .name = "nd_region",
+       },
+       .type = ND_DRIVER_REGION_BLK | ND_DRIVER_REGION_PMEM,
+};
+
+int __init nd_region_init(void)
+{
+       return nd_driver_register(&nd_region_driver);
+}
+
+void nd_region_exit(void)
+{
+       driver_unregister(&nd_region_driver.drv);
+}
+
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_PMEM);
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_REGION_BLK);
index 4bda2e0..b5c5b90 100644 (file)
@@ -47,11 +47,16 @@ static struct device_type nd_volatile_device_type = {
        .release = nd_region_release,
 };
 
-static bool is_nd_pmem(struct device *dev)
+bool is_nd_pmem(struct device *dev)
 {
        return dev ? dev->type == &nd_pmem_device_type : false;
 }
 
+bool is_nd_blk(struct device *dev)
+{
+       return dev ? dev->type == &nd_blk_device_type : false;
+}
+
 struct nd_region *to_nd_region(struct device *dev)
 {
        struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
@@ -61,6 +66,37 @@ struct nd_region *to_nd_region(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(to_nd_region);
 
+/**
+ * nd_region_to_nstype() - region to an integer namespace type
+ * @nd_region: region-device to interrogate
+ *
+ * This is the 'nstype' attribute of a region as well, an input to the
+ * MODALIAS for namespace devices, and bit number for a nvdimm_bus to match
+ * namespace devices with namespace drivers.
+ */
+int nd_region_to_nstype(struct nd_region *nd_region)
+{
+       if (is_nd_pmem(&nd_region->dev)) {
+               u16 i, alias;
+
+               for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) {
+                       struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+                       struct nvdimm *nvdimm = nd_mapping->nvdimm;
+
+                       if (nvdimm->flags & NDD_ALIASING)
+                               alias++;
+               }
+               if (alias)
+                       return ND_DEVICE_NAMESPACE_PMEM;
+               else
+                       return ND_DEVICE_NAMESPACE_IO;
+       } else if (is_nd_blk(&nd_region->dev)) {
+               return ND_DEVICE_NAMESPACE_BLK;
+       }
+
+       return 0;
+}
+
 static ssize_t size_show(struct device *dev,
                struct device_attribute *attr, char *buf)
 {
@@ -88,9 +124,37 @@ static ssize_t mappings_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(mappings);
 
+static ssize_t nstype_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_to_nstype(nd_region));
+}
+static DEVICE_ATTR_RO(nstype);
+
+static ssize_t init_namespaces_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nd_region_namespaces *num_ns = dev_get_drvdata(dev);
+       ssize_t rc;
+
+       nvdimm_bus_lock(dev);
+       if (num_ns)
+               rc = sprintf(buf, "%d/%d\n", num_ns->active, num_ns->count);
+       else
+               rc = -ENXIO;
+       nvdimm_bus_unlock(dev);
+
+       return rc;
+}
+static DEVICE_ATTR_RO(init_namespaces);
+
 static struct attribute *nd_region_attributes[] = {
        &dev_attr_size.attr,
+       &dev_attr_nstype.attr,
        &dev_attr_mappings.attr,
+       &dev_attr_init_namespaces.attr,
        NULL,
 };
 
index 39e7e60..37f966a 100644 (file)
@@ -71,8 +71,11 @@ struct nd_region_desc {
 
 struct nvdimm_bus;
 struct device;
-struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
-               struct nvdimm_bus_descriptor *nfit_desc);
+struct module;
+struct nvdimm_bus *__nvdimm_bus_register(struct device *parent,
+               struct nvdimm_bus_descriptor *nfit_desc, struct module *module);
+#define nvdimm_bus_register(parent, desc) \
+       __nvdimm_bus_register(parent, desc, THIS_MODULE)
 void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus);
 struct nvdimm_bus *to_nvdimm_bus(struct device *dev);
 struct nvdimm *to_nvdimm(struct device *dev);
index e074f67..da70e99 100644 (file)
@@ -26,6 +26,16 @@ static inline struct nd_device_driver *to_nd_device_driver(
                struct device_driver *drv)
 {
        return container_of(drv, struct nd_device_driver, drv);
+};
+
+struct nd_namespace_io {
+       struct device dev;
+       struct resource res;
+};
+
+static inline struct nd_namespace_io *to_nd_namespace_io(struct device *dev)
+{
+       return container_of(dev, struct nd_namespace_io, dev);
 }
 
 #define MODULE_ALIAS_ND_DEVICE(type) \
index 3764091..174b637 100644 (file)
@@ -177,8 +177,18 @@ static inline const char *nvdimm_cmd_name(unsigned cmd)
 
 
 #define ND_DEVICE_DIMM 1            /* nd_dimm: container for "config data" */
+#define ND_DEVICE_REGION_PMEM 2     /* nd_region: (parent of PMEM namespaces) */
+#define ND_DEVICE_REGION_BLK 3      /* nd_region: (parent of BLK namespaces) */
+#define ND_DEVICE_NAMESPACE_IO 4    /* legacy persistent memory */
+#define ND_DEVICE_NAMESPACE_PMEM 5  /* PMEM namespace (may alias with BLK) */
+#define ND_DEVICE_NAMESPACE_BLK 6   /* BLK namespace (may alias with PMEM) */
 
 enum nd_driver_flags {
        ND_DRIVER_DIMM            = 1 << ND_DEVICE_DIMM,
+       ND_DRIVER_REGION_PMEM     = 1 << ND_DEVICE_REGION_PMEM,
+       ND_DRIVER_REGION_BLK      = 1 << ND_DEVICE_REGION_BLK,
+       ND_DRIVER_NAMESPACE_IO    = 1 << ND_DEVICE_NAMESPACE_IO,
+       ND_DRIVER_NAMESPACE_PMEM  = 1 << ND_DEVICE_NAMESPACE_PMEM,
+       ND_DRIVER_NAMESPACE_BLK   = 1 << ND_DEVICE_NAMESPACE_BLK,
 };
 #endif /* __NDCTL_H__ */