[13/22] device-dax: use the dev_pagemap internal refcount

Submitted by Christoph Hellwig on June 13, 2019, 9:43 a.m.

Details

Message ID 20190613094326.24093-14-hch@lst.de
State New
Headers show
Series "Series without cover letter" ( rev: 2 1 ) in Nouveau

Not browsing as part of any series.

Commit Message

Christoph Hellwig June 13, 2019, 9:43 a.m.
The functionality is identical to the one currently open coded in
device-dax.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/dax/dax-private.h |  4 ---
 drivers/dax/device.c      | 52 +--------------------------------------
 2 files changed, 1 insertion(+), 55 deletions(-)

Patch hide | download patch | download mbox

diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index a45612148ca0..ed04a18a35be 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -51,8 +51,6 @@  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;
@@ -60,8 +58,6 @@  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 e23fa1bd8c97..a9d7c90ecf1e 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -14,37 +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(void *data)
-{
-	struct percpu_ref *ref = data;
-	struct dev_dax *dev_dax = ref_to_dev_dax(ref);
-
-	dev_dbg(&dev_dax->dev, "%s\n", __func__);
-	wait_for_completion(&dev_dax->cmp);
-	percpu_ref_exit(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)
 {
@@ -442,10 +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,
-};
-
 int dev_dax_probe(struct device *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
@@ -463,24 +428,9 @@  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;
-
-	rc = devm_add_action_or_reset(dev, dev_dax_percpu_exit, &dev_dax->ref);
-	if (rc)
-		return rc;
-
-	dev_dax->pgmap.ref = &dev_dax->ref;
-	dev_dax->pgmap.ops = &dev_dax_pagemap_ops;
 	addr = devm_memremap_pages(dev, &dev_dax->pgmap);
-	if (IS_ERR(addr)) {
-		devm_remove_action(dev, dev_dax_percpu_exit, &dev_dax->ref);
-		percpu_ref_exit(&dev_dax->ref);
+	if (IS_ERR(addr))
 		return PTR_ERR(addr);
-	}
 
 	inode = dax_inode(dax_dev);
 	cdev = inode->i_cdev;

Comments

On Thu, Jun 13, 2019 at 05:22:17PM -0700, Ira Weiny wrote:
> > -	dev_dax->pgmap.ref = &dev_dax->ref;
> 
> I don't think this exactly correct.  pgmap.ref is a pointer to the dev_dax ref
> structure.  Taking it away will cause devm_memremap_pages() to fail AFAICS.
> 
> I think you need to change struct dev_pagemap as well:

Take a look at the previous patch, which adds an internal_ref field
to dev_pagemap that ->ref is set up to point to if not otherwise
initialized.