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authorDan Williams <dan.j.williams@intel.com>2019-07-17 18:08:26 -0700
committerDan Williams <dan.j.williams@intel.com>2019-07-18 16:23:27 -0700
commit87a30e1f05d73a34e6d1895065541369131aaf1c (patch)
treea5582d3cd7723db8b7ad2f4801a5540c36c5266a /drivers/acpi
parentca6bf264f6d856f959c4239cda1047b587745c67 (diff)
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: Dan Williams <dan.j.williams@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/156341210661.292348.7014034644265455704.stgit@dwillia2-desk3.amr.corp.intel.com
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/nfit/core.c28
-rw-r--r--drivers/acpi/nfit/nfit.h24
2 files changed, 38 insertions, 14 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);