[PATCH V5 04/19] dax: Save the kva from memremap

From: John Groves

Date: Fri Jan 16 2026 - 14:01:34 EST


From: John Groves <john@xxxxxxxxxx>

Save the kva from memremap because we need it for iomap rw support.

Prior to famfs, there were no iomap users of /dev/dax - so the virtual
address from memremap was not needed.

Signed-off-by: John Groves <john@xxxxxxxxxx>
---
drivers/dax/dax-private.h | 9 +++++++--
drivers/dax/fsdev.c | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 0867115aeef2..f3cf0a664f1b 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -67,8 +67,12 @@ struct dev_dax_range {
/**
* struct dev_dax - instance data for a subdivision of a dax region, and
* data while the device is activated in the driver.
- * @region - parent region
- * @dax_dev - core dax functionality
+<<<<<<< Conflict 1 of 1
++++++++ Contents of side #1
+ * @region: parent region
+ * @dax_dev: core dax functionality
+ * @virt_addr: kva from memremap; used by fsdev_dax
+ * @align: alignment of this instance
* @target_node: effective numa node if dev_dax memory range is onlined
* @dyn_id: is this a dynamic or statically created instance
* @id: ida allocated id when the dax_region is not static
@@ -81,6 +85,7 @@ struct dev_dax_range {
struct dev_dax {
struct dax_region *region;
struct dax_device *dax_dev;
+ void *virt_addr;
unsigned int align;
int target_node;
bool dyn_id;
diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c
index 29b7345f65b1..72f78f606e06 100644
--- a/drivers/dax/fsdev.c
+++ b/drivers/dax/fsdev.c
@@ -201,6 +201,7 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax)
pr_debug("%s: offset detected phys=%llx pgmap_phys=%llx offset=%llx\n",
__func__, phys, pgmap_phys, data_offset);
}
+ dev_dax->virt_addr = addr + data_offset;

inode = dax_inode(dax_dev);
cdev = inode->i_cdev;
--
2.52.0