[PATCH v2 7/7] driver-core, libnvdimm: Let device subsystems add local lockdep coverage

From: Dan Williams
Date: Wed Jul 17 2019 - 21:22:49 EST

For good reason, the standard device_lock() is marked
lockdep_set_novalidate_class() because there is simply no sane way to
describe the myriad ways the device_lock() ordered with other locks.
However, that leaves subsystems that know their own local device_lock()
ordering rules to find lock ordering mistakes manually. Instead,
introduce an optional / additional lockdep-enabled lock that a subsystem
can acquire in all the same paths that the device_lock() is acquired.

A conversion of the NFIT driver and NVDIMM subsystem to a
lockdep-validate device_lock() scheme is included. The
debug_nvdimm_lock() implementation implements the correct lock-class and
stacking order for the libnvdimm device topology hierarchy.

Yes, this is a hack, but hopefully it is a useful hack for other
subsystems device_lock() debug sessions. Quoting Greg:

"Yeah, it feels a bit hacky but it's really up to a subsystem to mess up
using it as much as anything else, so user beware :)

I don't object to it if it makes things easier for you to debug."

Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit/core.c | 28 ++++++++--------
drivers/acpi/nfit/nfit.h | 24 ++++++++++++++
drivers/base/core.c | 3 ++
drivers/nvdimm/btt_devs.c | 16 +++++----
drivers/nvdimm/bus.c | 28 ++++++++++------
drivers/nvdimm/core.c | 10 +++---
drivers/nvdimm/dimm_devs.c | 4 +-
drivers/nvdimm/namespace_devs.c | 36 ++++++++++-----------
drivers/nvdimm/nd-core.h | 68 +++++++++++++++++++++++++++++++++++++++
drivers/nvdimm/pfn_devs.c | 24 +++++++-------
drivers/nvdimm/pmem.c | 4 +-
drivers/nvdimm/region.c | 2 +
drivers/nvdimm/region_devs.c | 16 +++++----
include/linux/device.h | 5 +++
14 files changed, 187 insertions(+), 81 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 23022cf20d26..f22139458ce1 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1282,7 +1282,7 @@ static ssize_t hw_error_scrub_store(struct device *dev,
if (rc)
return rc;

- device_lock(dev);
+ nfit_device_lock(dev);
nd_desc = dev_get_drvdata(dev);
if (nd_desc) {
struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
@@ -1299,7 +1299,7 @@ static ssize_t hw_error_scrub_store(struct device *dev,
break;
}
}
- device_unlock(dev);
+ nfit_device_unlock(dev);
if (rc)
return rc;
return size;
@@ -1319,7 +1319,7 @@ static ssize_t scrub_show(struct device *dev,
ssize_t rc = -ENXIO;
bool busy;

- device_lock(dev);
+ nfit_device_lock(dev);
nd_desc = dev_get_drvdata(dev);
if (!nd_desc) {
device_unlock(dev);
@@ -1339,7 +1339,7 @@ static ssize_t scrub_show(struct device *dev,
}

mutex_unlock(&acpi_desc->init_mutex);
- device_unlock(dev);
+ nfit_device_unlock(dev);
return rc;
}

@@ -1356,14 +1356,14 @@ static ssize_t scrub_store(struct device *dev,
if (val != 1)
return -EINVAL;

- device_lock(dev);
+ nfit_device_lock(dev);
nd_desc = dev_get_drvdata(dev);
if (nd_desc) {
struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);

rc = acpi_nfit_ars_rescan(acpi_desc, ARS_REQ_LONG);
}
- device_unlock(dev);
+ nfit_device_unlock(dev);
if (rc)
return rc;
return size;
@@ -1749,9 +1749,9 @@ static void acpi_nvdimm_notify(acpi_handle handle, u32 event, void *data)
struct acpi_device *adev = data;
struct device *dev = &adev->dev;

- device_lock(dev->parent);
+ nfit_device_lock(dev->parent);
__acpi_nvdimm_notify(dev, event);
- device_unlock(dev->parent);
+ nfit_device_unlock(dev->parent);
}

static bool acpi_nvdimm_has_method(struct acpi_device *adev, char *method)
@@ -3457,8 +3457,8 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc)
struct device *dev = acpi_desc->dev;

/* Bounce the device lock to flush acpi_nfit_add / acpi_nfit_notify */
- device_lock(dev);
- device_unlock(dev);
+ nfit_device_lock(dev);
+ nfit_device_unlock(dev);

/* Bounce the init_mutex to complete initial registration */
mutex_lock(&acpi_desc->init_mutex);
@@ -3602,8 +3602,8 @@ void acpi_nfit_shutdown(void *data)
* acpi_nfit_ars_rescan() submissions have had a chance to
* either submit or see ->cancel set.
*/
- device_lock(bus_dev);
- device_unlock(bus_dev);
+ nfit_device_lock(bus_dev);
+ nfit_device_unlock(bus_dev);

flush_workqueue(nfit_wq);
}
@@ -3746,9 +3746,9 @@ EXPORT_SYMBOL_GPL(__acpi_nfit_notify);

static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
{
- device_lock(&adev->dev);
+ nfit_device_lock(&adev->dev);
__acpi_nfit_notify(&adev->dev, adev->handle, event);
- device_unlock(&adev->dev);
+ nfit_device_unlock(&adev->dev);
}

static const struct acpi_device_id acpi_nfit_ids[] = {
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index 6ee2b02af73e..24241941181c 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -312,6 +312,30 @@ static inline struct acpi_nfit_desc *to_acpi_desc(
return container_of(nd_desc, struct acpi_nfit_desc, nd_desc);
}

+#ifdef CONFIG_PROVE_LOCKING
+static inline void nfit_device_lock(struct device *dev)
+{
+ device_lock(dev);
+ mutex_lock(&dev->lockdep_mutex);
+}
+
+static inline void nfit_device_unlock(struct device *dev)
+{
+ mutex_unlock(&dev->lockdep_mutex);
+ device_unlock(dev);
+}
+#else
+static inline void nfit_device_lock(struct device *dev)
+{
+ device_lock(dev);
+}
+
+static inline void nfit_device_unlock(struct device *dev)
+{
+ device_unlock(dev);
+}
+#endif
+
const guid_t *to_nfit_uuid(enum nfit_uuids id);
int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *nfit, acpi_size sz);
void acpi_nfit_shutdown(void *data);
diff --git a/drivers/base/core.c b/drivers/base/core.c
index eaf3aa0cb803..4825949d6547 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1663,6 +1663,9 @@ void device_initialize(struct device *dev)
kobject_init(&dev->kobj, &device_ktype);
INIT_LIST_HEAD(&dev->dma_pools);
mutex_init(&dev->mutex);
+#ifdef CONFIG_PROVE_LOCKING
+ mutex_init(&dev->lockdep_mutex);
+#endif
lockdep_set_novalidate_class(&dev->mutex);
spin_lock_init(&dev->devres_lock);
INIT_LIST_HEAD(&dev->devres_head);
diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 62d00fffa4af..3508a79110c7 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -62,14 +62,14 @@ static ssize_t sector_size_store(struct device *dev,
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
btt_lbasize_supported);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc ? rc : len;
}
@@ -91,11 +91,11 @@ static ssize_t uuid_store(struct device *dev,
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc ? rc : len;
}
@@ -120,13 +120,13 @@ static ssize_t namespace_store(struct device *dev,
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
@@ -138,14 +138,14 @@ static ssize_t size_show(struct device *dev,
struct nd_btt *nd_btt = to_nd_btt(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
if (dev->driver)
rc = sprintf(buf, "%llu\n", nd_btt->size);
else {
/* no size to convey if the btt instance is disabled */
rc = -ENXIO;
}
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index df41f3571dc9..798c5c4aea9c 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -26,7 +26,7 @@

int nvdimm_major;
static int nvdimm_bus_major;
-static struct class *nd_class;
+struct class *nd_class;
static DEFINE_IDA(nd_ida);

static int to_nd_device_type(struct device *dev)
@@ -91,7 +91,10 @@ static int nvdimm_bus_probe(struct device *dev)
dev->driver->name, dev_name(dev));

nvdimm_bus_probe_start(nvdimm_bus);
+ debug_nvdimm_lock(dev);
rc = nd_drv->probe(dev);
+ debug_nvdimm_unlock(dev);
+
if (rc == 0)
nd_region_probe_success(nvdimm_bus, dev);
else
@@ -113,8 +116,11 @@ static int nvdimm_bus_remove(struct device *dev)
struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
int rc = 0;

- if (nd_drv->remove)
+ if (nd_drv->remove) {
+ debug_nvdimm_lock(dev);
rc = nd_drv->remove(dev);
+ debug_nvdimm_unlock(dev);
+ }
nd_region_disable(nvdimm_bus, dev);

dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
@@ -140,7 +146,7 @@ static void nvdimm_bus_shutdown(struct device *dev)

void nd_device_notify(struct device *dev, enum nvdimm_event event)
{
- device_lock(dev);
+ nd_device_lock(dev);
if (dev->driver) {
struct nd_device_driver *nd_drv;

@@ -148,7 +154,7 @@ void nd_device_notify(struct device *dev, enum nvdimm_event event)
if (nd_drv->notify)
nd_drv->notify(dev, event);
}
- device_unlock(dev);
+ nd_device_unlock(dev);
}
EXPORT_SYMBOL(nd_device_notify);

@@ -296,7 +302,7 @@ static void nvdimm_bus_release(struct device *dev)
kfree(nvdimm_bus);
}

-static bool is_nvdimm_bus(struct device *dev)
+bool is_nvdimm_bus(struct device *dev)
{
return dev->release == nvdimm_bus_release;
}
@@ -575,9 +581,9 @@ void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
* or otherwise let the async path handle it if the
* unregistration was already queued.
*/
- device_lock(dev);
+ nd_device_lock(dev);
killed = kill_device(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

if (!killed)
return;
@@ -888,10 +894,10 @@ void wait_nvdimm_bus_probe_idle(struct device *dev)
if (nvdimm_bus->probe_active == 0)
break;
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);
wait_event(nvdimm_bus->wait,
nvdimm_bus->probe_active == 0);
- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
} while (true);
}
@@ -1107,7 +1113,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
goto out;
}

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, func, buf);
if (rc)
@@ -1129,7 +1135,7 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,

out_unlock:
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);
out:
kfree(in_env);
kfree(out_env);
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 5e1f060547bf..9204f1e9fd14 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -246,7 +246,7 @@ static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
*
* Enforce that uuids can only be changed while the device is disabled
* (driver detached)
- * LOCKING: expects device_lock() is held on entry
+ * LOCKING: expects nd_device_lock() is held on entry
*/
int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
size_t len)
@@ -347,15 +347,15 @@ static DEVICE_ATTR_RO(provider);

static int flush_namespaces(struct device *dev, void *data)
{
- device_lock(dev);
- device_unlock(dev);
+ nd_device_lock(dev);
+ nd_device_unlock(dev);
return 0;
}

static int flush_regions_dimms(struct device *dev, void *data)
{
- device_lock(dev);
- device_unlock(dev);
+ nd_device_lock(dev);
+ nd_device_unlock(dev);
device_for_each_child(dev, NULL, flush_namespaces);
return 0;
}
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index dfecd6e17043..29a065e769ea 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -484,12 +484,12 @@ static ssize_t security_store(struct device *dev,
* done while probing is idle and the DIMM is not in active use
* in any region.
*/
- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
rc = __security_store(dev, buf, len);
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index a434a5964cb9..92cd809d7e43 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -410,7 +410,7 @@ static ssize_t alt_name_store(struct device *dev,
struct nd_region *nd_region = to_nd_region(dev->parent);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
rc = __alt_name_store(dev, buf, len);
@@ -418,7 +418,7 @@ static ssize_t alt_name_store(struct device *dev,
rc = nd_namespace_label_update(nd_region, dev);
dev_dbg(dev, "%s(%zd)\n", rc < 0 ? "fail " : "", rc);
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc < 0 ? rc : len;
}
@@ -1077,7 +1077,7 @@ static ssize_t size_store(struct device *dev,
if (rc)
return rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
rc = __size_store(dev, val);
@@ -1103,7 +1103,7 @@ static ssize_t size_store(struct device *dev,
dev_dbg(dev, "%llx %s (%d)\n", val, rc < 0 ? "fail" : "success", rc);

nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc < 0 ? rc : len;
}
@@ -1286,7 +1286,7 @@ static ssize_t uuid_store(struct device *dev,
} else
return -ENXIO;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
if (to_ndns(dev)->claim)
@@ -1302,7 +1302,7 @@ static ssize_t uuid_store(struct device *dev,
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc < 0 ? rc : len;
}
@@ -1376,7 +1376,7 @@ static ssize_t sector_size_store(struct device *dev,
} else
return -ENXIO;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
if (to_ndns(dev)->claim)
rc = -EBUSY;
@@ -1387,7 +1387,7 @@ static ssize_t sector_size_store(struct device *dev,
dev_dbg(dev, "result: %zd %s: %s%s", rc, rc < 0 ? "tried" : "wrote",
buf, buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc ? rc : len;
}
@@ -1502,9 +1502,9 @@ static ssize_t holder_show(struct device *dev,
struct nd_namespace_common *ndns = to_ndns(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
rc = sprintf(buf, "%s\n", ndns->claim ? dev_name(ndns->claim) : "");
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
@@ -1541,7 +1541,7 @@ static ssize_t holder_class_store(struct device *dev,
struct nd_region *nd_region = to_nd_region(dev->parent);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
rc = __holder_class_store(dev, buf);
@@ -1549,7 +1549,7 @@ static ssize_t holder_class_store(struct device *dev,
rc = nd_namespace_label_update(nd_region, dev);
dev_dbg(dev, "%s(%zd)\n", rc < 0 ? "fail " : "", rc);
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc < 0 ? rc : len;
}
@@ -1560,7 +1560,7 @@ static ssize_t holder_class_show(struct device *dev,
struct nd_namespace_common *ndns = to_ndns(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
if (ndns->claim_class == NVDIMM_CCLASS_NONE)
rc = sprintf(buf, "\n");
else if ((ndns->claim_class == NVDIMM_CCLASS_BTT) ||
@@ -1572,7 +1572,7 @@ static ssize_t holder_class_show(struct device *dev,
rc = sprintf(buf, "dax\n");
else
rc = sprintf(buf, "<unknown>\n");
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
@@ -1586,7 +1586,7 @@ static ssize_t mode_show(struct device *dev,
char *mode;
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
claim = ndns->claim;
if (claim && is_nd_btt(claim))
mode = "safe";
@@ -1599,7 +1599,7 @@ static ssize_t mode_show(struct device *dev,
else
mode = "raw";
rc = sprintf(buf, "%s\n", mode);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
@@ -1703,8 +1703,8 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
* Flush any in-progess probes / removals in the driver
* for the raw personality of this namespace.
*/
- device_lock(&ndns->dev);
- device_unlock(&ndns->dev);
+ nd_device_lock(&ndns->dev);
+ nd_device_unlock(&ndns->dev);
if (ndns->dev.driver) {
dev_dbg(&ndns->dev, "is active, can't bind %s\n",
dev_name(dev));
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 6cd470547106..0ac52b6eb00e 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -9,6 +9,7 @@
#include <linux/sizes.h>
#include <linux/mutex.h>
#include <linux/nd.h>
+#include "nd.h"

extern struct list_head nvdimm_bus_list;
extern struct mutex nvdimm_bus_list_mutex;
@@ -182,4 +183,71 @@ ssize_t nd_namespace_store(struct device *dev,
struct nd_namespace_common **_ndns, const char *buf,
size_t len);
struct nd_pfn *to_nd_pfn_safe(struct device *dev);
+bool is_nvdimm_bus(struct device *dev);
+
+#ifdef CONFIG_PROVE_LOCKING
+extern struct class *nd_class;
+
+enum {
+ LOCK_BUS,
+ LOCK_NDCTL,
+ LOCK_REGION,
+ LOCK_DIMM = LOCK_REGION,
+ LOCK_NAMESPACE,
+ LOCK_CLAIM,
+};
+
+static inline void debug_nvdimm_lock(struct device *dev)
+{
+ if (is_nd_region(dev))
+ mutex_lock_nested(&dev->lockdep_mutex, LOCK_REGION);
+ else if (is_nvdimm(dev))
+ mutex_lock_nested(&dev->lockdep_mutex, LOCK_DIMM);
+ else if (is_nd_btt(dev) || is_nd_pfn(dev) || is_nd_dax(dev))
+ mutex_lock_nested(&dev->lockdep_mutex, LOCK_CLAIM);
+ else if (dev->parent && (is_nd_region(dev->parent)))
+ mutex_lock_nested(&dev->lockdep_mutex, LOCK_NAMESPACE);
+ else if (is_nvdimm_bus(dev))
+ mutex_lock_nested(&dev->lockdep_mutex, LOCK_BUS);
+ else if (dev->class && dev->class == nd_class)
+ mutex_lock_nested(&dev->lockdep_mutex, LOCK_NDCTL);
+ else
+ dev_WARN(dev, "unknown lock level\n");
+}
+
+static inline void debug_nvdimm_unlock(struct device *dev)
+{
+ mutex_unlock(&dev->lockdep_mutex);
+}
+
+static inline void nd_device_lock(struct device *dev)
+{
+ device_lock(dev);
+ debug_nvdimm_lock(dev);
+}
+
+static inline void nd_device_unlock(struct device *dev)
+{
+ debug_nvdimm_unlock(dev);
+ device_unlock(dev);
+}
+#else
+static inline void nd_device_lock(struct device *dev)
+{
+ device_lock(dev);
+}
+
+static inline void nd_device_unlock(struct device *dev)
+{
+ device_unlock(dev);
+}
+
+static inline void debug_nvdimm_lock(struct device *dev)
+{
+}
+
+static inline void debug_nvdimm_unlock(struct device *dev)
+{
+}
+#endif
#endif /* __ND_CORE_H__ */
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 0f81fc56bbfd..9b09fe18e666 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -67,7 +67,7 @@ static ssize_t mode_store(struct device *dev,
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc = 0;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
if (dev->driver)
rc = -EBUSY;
@@ -89,7 +89,7 @@ static ssize_t mode_store(struct device *dev,
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc ? rc : len;
}
@@ -132,14 +132,14 @@ static ssize_t align_store(struct device *dev,
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_size_select_store(dev, buf, &nd_pfn->align,
nd_pfn_supported_alignments());
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc ? rc : len;
}
@@ -161,11 +161,11 @@ static ssize_t uuid_store(struct device *dev,
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc ? rc : len;
}
@@ -190,13 +190,13 @@ static ssize_t namespace_store(struct device *dev,
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
buf[len - 1] == '\n' ? "" : "\n");
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
@@ -208,7 +208,7 @@ static ssize_t resource_show(struct device *dev,
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
if (dev->driver) {
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
u64 offset = __le64_to_cpu(pfn_sb->dataoff);
@@ -222,7 +222,7 @@ static ssize_t resource_show(struct device *dev,
/* no address to convey if the pfn instance is disabled */
rc = -ENXIO;
}
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
@@ -234,7 +234,7 @@ static ssize_t size_show(struct device *dev,
struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
if (dev->driver) {
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
u64 offset = __le64_to_cpu(pfn_sb->dataoff);
@@ -250,7 +250,7 @@ static ssize_t size_show(struct device *dev,
/* no size to convey if the pfn instance is disabled */
rc = -ENXIO;
}
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 28cb44c61d4a..53797e7be18a 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -520,8 +520,8 @@ static int nd_pmem_remove(struct device *dev)
nvdimm_namespace_detach_btt(to_nd_btt(dev));
else {
/*
- * Note, this assumes device_lock() context to not race
- * nd_pmem_notify()
+ * Note, this assumes nd_device_lock() context to not
+ * race nd_pmem_notify()
*/
sysfs_put(pmem->bb_state);
pmem->bb_state = NULL;
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
index 488c47ac4c4a..37bf8719a2a4 100644
--- a/drivers/nvdimm/region.c
+++ b/drivers/nvdimm/region.c
@@ -102,7 +102,7 @@ static int nd_region_remove(struct device *dev)
nvdimm_bus_unlock(dev);

/*
- * Note, this assumes device_lock() context to not race
+ * Note, this assumes nd_device_lock() context to not race
* nd_region_notify()
*/
sysfs_put(nd_region->bb_state);
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index a15276cdec7d..91b5a7ade0d5 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -329,7 +329,7 @@ static ssize_t set_cookie_show(struct device *dev,
* the v1.1 namespace label cookie definition. To read all this
* data we need to wait for probing to settle.
*/
- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
if (nd_region->ndr_mappings) {
@@ -346,7 +346,7 @@ static ssize_t set_cookie_show(struct device *dev,
}
}
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

if (rc)
return rc;
@@ -422,12 +422,12 @@ static ssize_t available_size_show(struct device *dev,
* memory nvdimm_bus_lock() is dropped, but that's userspace's
* problem to not race itself.
*/
- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
available = nd_region_available_dpa(nd_region);
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return sprintf(buf, "%llu\n", available);
}
@@ -439,12 +439,12 @@ static ssize_t max_available_extent_show(struct device *dev,
struct nd_region *nd_region = to_nd_region(dev);
unsigned long long available = 0;

- device_lock(dev);
+ nd_device_lock(dev);
nvdimm_bus_lock(dev);
wait_nvdimm_bus_probe_idle(dev);
available = nd_region_allocatable_dpa(nd_region);
nvdimm_bus_unlock(dev);
- device_unlock(dev);
+ nd_device_unlock(dev);

return sprintf(buf, "%llu\n", available);
}
@@ -563,12 +563,12 @@ static ssize_t region_badblocks_show(struct device *dev,
struct nd_region *nd_region = to_nd_region(dev);
ssize_t rc;

- device_lock(dev);
+ nd_device_lock(dev);
if (dev->driver)
rc = badblocks_show(&nd_region->bb, buf, 0);
else
rc = -ENXIO;
- device_unlock(dev);
+ nd_device_unlock(dev);

return rc;
}
diff --git a/include/linux/device.h b/include/linux/device.h
index 0da5c67f6be1..9237b857b598 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -909,6 +909,8 @@ struct dev_links_info {
* This identifies the device type and carries type-specific
* information.
* @mutex: Mutex to synchronize calls to its driver.
+ * @lockdep_mutex: An optional debug lock that a subsystem can use as a
+ * peer lock to gain localized lockdep coverage of the device_lock.
* @bus: Type of bus device is on.
* @driver: Which driver has allocated this
* @platform_data: Platform data specific to the device.
@@ -991,6 +993,9 @@ struct device {
core doesn't touch it */
void *driver_data; /* Driver data, set and get with
dev_set_drvdata/dev_get_drvdata */
+#ifdef CONFIG_PROVE_LOCKING
+ struct mutex lockdep_mutex;
+#endif
struct mutex mutex; /* mutex to synchronize calls to
* its driver.
*/