[PATCH v6 11/21] libnvdimm, nfit: add interleave-set state-tracking infrastructure

From: Dan Williams
Date: Thu Jun 11 2015 - 16:14:00 EST

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@xxxxxxx>
Cc: <linux-acpi@xxxxxxxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Robert Moore <robert.moore@xxxxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit.c | 93 +++++++++++++++++++++++++++++++++++++++++-
drivers/nvdimm/bus.c | 59 ++++++++++++++++++++++++++-
drivers/nvdimm/core.c | 17 ++++++++
drivers/nvdimm/dimm_devs.c | 19 ++++++++-
drivers/nvdimm/nd-core.h | 10 ++++-
drivers/nvdimm/nd.h | 1
drivers/nvdimm/region_devs.c | 69 +++++++++++++++++++++++++++++++
include/linux/libnvdimm.h | 6 +++
8 files changed, 269 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index e86beb50f54f..dc5a44554e55 100644
--- 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 4b77665a6cc8..ffb43cada625 100644
--- 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 e16a22902e90..74adb225d132 100644
--- 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 b3ae86f2e1da..bdf8241b6525 100644
--- 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 0e9b41fd2546..6a4b2c066ee7 100644
--- 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 bc5a08e36a25..0285e4588b03 100644
--- 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 b5c5b9095b28..1571424578f0 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 <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 37f966aff386..1b627b109360 100644
--- 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__ */

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