Right now, only static dax regions have a valid @pgmap pointer in its
struct dev_dax. Dynamic dax case however, do not.
In preparation for device-dax compound devmap support, make sure that
dev_dax pgmap field is set after it has been allocated and initialized.
dynamic dax device have the @pgmap is allocated at probe() and it's
managed by devm (contrast to static dax region which a pgmap is provided
and dax core kfrees it). So in addition to ensure a valid @pgmap, clear
the pgmap when the dynamic dax device is released to avoid the same
pgmap ranges to be re-requested across multiple region device reconfigs.
Add a static_dev_dax() and use that helper in dev_dax_probe() to ensure
the initialization differences between dynamic and static regions are
more explicit. While at it, consolidate the ranges initialization when we
allocate the @pgmap for the dynamic dax region case.
Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
---
drivers/dax/bus.c | 14 ++++++++++++++
drivers/dax/bus.h | 1 +
drivers/dax/device.c | 26 +++++++++++++++++++-------
3 files changed, 34 insertions(+), 7 deletions(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 6cc4da4c713d..19dd83d3f3ea 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -134,6 +134,12 @@ 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 +369,14 @@ 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);
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 1e946ad7780a..4acdfee7dd59 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -48,6 +48,7 @@ int __dax_driver_register(struct dax_device_driver *dax_drv,
__dax_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
void dax_driver_unregister(struct dax_device_driver *dax_drv);
void kill_dev_dax(struct dev_dax *dev_dax);
+bool static_dev_dax(struct dev_dax *dev_dax);
#if IS_ENABLED(CONFIG_DEV_DAX_PMEM_COMPAT)
int dev_dax_probe(struct dev_dax *dev_dax);
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index d6796a3115a6..a65c67ab5ee0 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -398,18 +398,33 @@ int dev_dax_probe(struct dev_dax *dev_dax)
void *addr;
int rc, i;
- pgmap = dev_dax->pgmap;
- if (dev_WARN_ONCE(dev, pgmap && dev_dax->nr_range > 1,
- "static pgmap / multi-range device conflict\n"))
+ if (static_dev_dax(dev_dax) && dev_dax->nr_range > 1) {
+ dev_warn(dev, "static pgmap / multi-range device conflict\n");
return -EINVAL;
+ }
+
+ if (static_dev_dax(dev_dax)) {
+ pgmap = dev_dax->pgmap;
+ } else {
+ if (dev_dax->pgmap) {
+ dev_warn(dev,
+ "dynamic-dax with pre-populated page map\n");
+ return -EINVAL;
+ }
- if (!pgmap) {
pgmap = devm_kzalloc(
dev, struct_size(pgmap, ranges, dev_dax->nr_range - 1),
GFP_KERNEL);
if (!pgmap)
return -ENOMEM;
+
pgmap->nr_range = dev_dax->nr_range;
+ dev_dax->pgmap = pgmap;
+
+ for (i = 0; i < dev_dax->nr_range; i++) {
+ struct range *range = &dev_dax->ranges[i].range;
+ pgmap->ranges[i] = *range;
+ }
}
for (i = 0; i < dev_dax->nr_range; i++) {
@@ -421,9 +436,6 @@ int dev_dax_probe(struct dev_dax *dev_dax)
i, range->start, range->end);
return -EBUSY;
}
- /* don't update the range for static pgmap */
- if (!dev_dax->pgmap)
- pgmap->ranges[i] = *range;
}
pgmap->type = MEMORY_DEVICE_GENERIC;
--
2.17.2
