Commit 87a30e1f authored by Dan Williams's avatar Dan Williams
Browse files

driver-core, libnvdimm: Let device subsystems add local lockdep coverage



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@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
parent ca6bf264
......@@ -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[] = {
......
......@@ -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);
......
......@@ -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);
......
......@@ -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;
}
......
......@@ -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);
......
......@@ -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;
}
......
......@@ -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;
}
......
......@@ -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));
......
......@@ -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__ */
......@@ -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-&