[PATCH 16/25] device-dax: use the dev_pagemap internal refcount

[Christoph Hellwig]

The functionality is identical to the one currently open coded in
device-dax.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/dax/dax-private.h |  4 ----
 drivers/dax/device.c      | 43 ---------------------------------------
 2 files changed, 47 deletions(-)

diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index b4177aafbbd1..c915889d1769 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -43,8 +43,6 @@ struct dax_region {
  * @target_node: effective numa node if dev_dax memory range is onlined
  * @dev - device core
  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
- * @ref: pgmap reference count (driver owned)
- * @cmp: @ref final put completion (driver owned)
  */
 struct dev_dax {
        struct dax_region *region;
@@ -52,8 +50,6 @@ struct dev_dax {
        int target_node;
        struct device dev;
        struct dev_pagemap pgmap;
-       struct percpu_ref ref;
-       struct completion cmp;
 };
 
 static inline struct dev_dax *to_dev_dax(struct device *dev)
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index b5257038c188..1af823b2fe6b 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -14,36 +14,6 @@
 #include "dax-private.h"
 #include "bus.h"
 
-static struct dev_dax *ref_to_dev_dax(struct percpu_ref *ref)
-{
-       return container_of(ref, struct dev_dax, ref);
-}
-
-static void dev_dax_percpu_release(struct percpu_ref *ref)
-{
-       struct dev_dax *dev_dax = ref_to_dev_dax(ref);
-
-       dev_dbg(&dev_dax->dev, "%s\n", __func__);
-       complete(&dev_dax->cmp);
-}
-
-static void dev_dax_percpu_exit(struct dev_pagemap *pgmap)
-{
-       struct dev_dax *dev_dax = container_of(pgmap, struct dev_dax, pgmap);
-
-       dev_dbg(&dev_dax->dev, "%s\n", __func__);
-       wait_for_completion(&dev_dax->cmp);
-       percpu_ref_exit(pgmap->ref);
-}
-
-static void dev_dax_percpu_kill(struct dev_pagemap *pgmap)
-{
-       struct dev_dax *dev_dax = container_of(pgmap, struct dev_dax, pgmap);
-
-       dev_dbg(&dev_dax->dev, "%s\n", __func__);
-       percpu_ref_kill(pgmap->ref);
-}
-
 static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
                const char *func)
 {
@@ -441,11 +411,6 @@ static void dev_dax_kill(void *dev_dax)
        kill_dev_dax(dev_dax);
 }
 
-static const struct dev_pagemap_ops dev_dax_pagemap_ops = {
-       .kill           = dev_dax_percpu_kill,
-       .cleanup        = dev_dax_percpu_exit,
-};
-
 int dev_dax_probe(struct device *dev)
 {
        struct dev_dax *dev_dax = to_dev_dax(dev);
@@ -463,15 +428,7 @@ int dev_dax_probe(struct device *dev)
                return -EBUSY;
        }
 
-       init_completion(&dev_dax->cmp);
-       rc = percpu_ref_init(&dev_dax->ref, dev_dax_percpu_release, 0,
-                       GFP_KERNEL);
-       if (rc)
-               return rc;
-
-       dev_dax->pgmap.ref = &dev_dax->ref;
        dev_dax->pgmap.type = MEMORY_DEVICE_DEVDAX;
-       dev_dax->pgmap.ops = &dev_dax_pagemap_ops;
        addr = devm_memremap_pages(dev, &dev_dax->pgmap);
        if (IS_ERR(addr))
                return PTR_ERR(addr);
-- 
2.20.1