diff options
Diffstat (limited to 'drivers/dax/bus.c')
| -rw-r--r-- | drivers/dax/bus.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 6cc4da4c713d..a22350e822fa 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -129,11 +129,35 @@ ATTRIBUTE_GROUPS(dax_drv); static int dax_bus_match(struct device *dev, struct device_driver *drv); +/* + * Static dax regions are regions created by an external subsystem + * nvdimm where a single range is assigned. Its boundaries are by the external + * subsystem and are usually limited to one physical memory range. For example, + * for PMEM it is usually defined by NVDIMM Namespace boundaries (i.e. a + * single contiguous range) + * + * On dynamic dax regions, the assigned region can be partitioned by dax core + * into multiple subdivisions. A subdivision is represented into one + * /dev/daxN.M device composed by one or more potentially discontiguous ranges. + * + * When allocating a dax region, drivers must set whether it's static + * (IORESOURCE_DAX_STATIC). On static dax devices, the @pgmap is pre-assigned + * to dax core when calling devm_create_dev_dax(), whereas in dynamic dax + * devices it is NULL but afterwards allocated by dax core on device ->probe(). + * Care is needed to make sure that dynamic dax devices are torn down with a + * cleared @pgmap field (see kill_dev_dax()). + */ static bool is_static(struct dax_region *dax_region) { return (dax_region->res.flags & IORESOURCE_DAX_STATIC) != 0; } +bool static_dev_dax(struct dev_dax *dev_dax) +{ + return is_static(dev_dax->region); +} +EXPORT_SYMBOL_GPL(static_dev_dax); + static u64 dev_dax_size(struct dev_dax *dev_dax) { u64 size = 0; @@ -363,6 +387,14 @@ void kill_dev_dax(struct dev_dax *dev_dax) kill_dax(dax_dev); unmap_mapping_range(inode->i_mapping, 0, 0, 1); + + /* + * Dynamic dax region have the pgmap allocated via dev_kzalloc() + * and thus freed by devm. Clear the pgmap to not have stale pgmap + * ranges on probe() from previous reconfigurations of region devices. + */ + if (!static_dev_dax(dev_dax)) + dev_dax->pgmap = NULL; } EXPORT_SYMBOL_GPL(kill_dev_dax); |