[PATCH v4 6/7] dax/hmem: Save the DAX HMEM platform device pointer

[Smita Koralahalli]

From: Nathan Fontenot <nathan.fontenot@xxxxxxx>

To enable registration of HMEM devices for SOFT RESERVED regions after
the DAX HMEM device is initialized, this patch saves a reference to the
DAX HMEM platform device.

This saved pointer will be used in a follow-up patch to allow late
registration of SOFT RESERVED memory ranges. It also enables
simplification of the walk_hmem_resources() by removing the need to
pass a struct device argument.

There are no functional changes.

Co-developed-by: Nathan Fontenot <Nathan.Fontenot@xxxxxxx>
Signed-off-by: Nathan Fontenot <Nathan.Fontenot@xxxxxxx>
Co-developed-by: Terry Bowman <terry.bowman@xxxxxxx>
Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@xxxxxxx>
---
 drivers/dax/hmem/device.c | 4 ++--
 drivers/dax/hmem/hmem.c   | 9 ++++++---
 include/linux/dax.h       | 5 ++---
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/dax/hmem/device.c b/drivers/dax/hmem/device.c
index f9e1a76a04a9..59ad44761191 100644
--- a/drivers/dax/hmem/device.c
+++ b/drivers/dax/hmem/device.c
@@ -17,14 +17,14 @@ static struct resource hmem_active = {
 	.flags = IORESOURCE_MEM,
 };
 
-int walk_hmem_resources(struct device *host, walk_hmem_fn fn)
+int walk_hmem_resources(walk_hmem_fn fn)
 {
 	struct resource *res;
 	int rc = 0;
 
 	mutex_lock(&hmem_resource_lock);
 	for (res = hmem_active.child; res; res = res->sibling) {
-		rc = fn(host, (int) res->desc, res);
+		rc = fn((int) res->desc, res);
 		if (rc)
 			break;
 	}
diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index 5e7c53f18491..3aedef5f1be1 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -9,6 +9,8 @@
 static bool region_idle;
 module_param_named(region_idle, region_idle, bool, 0644);
 
+static struct platform_device *dax_hmem_pdev;
+
 static int dax_hmem_probe(struct platform_device *pdev)
 {
 	unsigned long flags = IORESOURCE_DAX_KMEM;
@@ -59,9 +61,9 @@ static void release_hmem(void *pdev)
 	platform_device_unregister(pdev);
 }
 
-static int hmem_register_device(struct device *host, int target_nid,
-				const struct resource *res)
+static int hmem_register_device(int target_nid, const struct resource *res)
 {
+	struct device *host = &dax_hmem_pdev->dev;
 	struct platform_device *pdev;
 	struct memregion_info info;
 	long id;
@@ -125,7 +127,8 @@ static int hmem_register_device(struct device *host, int target_nid,
 
 static int dax_hmem_platform_probe(struct platform_device *pdev)
 {
-	return walk_hmem_resources(&pdev->dev, hmem_register_device);
+	dax_hmem_pdev = pdev;
+	return walk_hmem_resources(hmem_register_device);
 }
 
 static struct platform_driver dax_hmem_platform_driver = {
diff --git a/include/linux/dax.h b/include/linux/dax.h
index dcc9fcdf14e4..a4ad3708ea35 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -305,7 +305,6 @@ static inline void hmem_register_resource(int target_nid, struct resource *r)
 }
 #endif
 
-typedef int (*walk_hmem_fn)(struct device *dev, int target_nid,
-			    const struct resource *res);
-int walk_hmem_resources(struct device *dev, walk_hmem_fn fn);
+typedef int (*walk_hmem_fn)(int target_nid, const struct resource *res);
+int walk_hmem_resources(walk_hmem_fn fn);
 #endif
-- 
2.17.1