[PATCH v6 1/2] nvmem: remove duplicated reference counting

[Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>]

Commit c1de7f43bd84 ("nvmem: use kref") introduced reference counting
with kref to an already reference counted nvmem_device structure. We
only need one refcount so use the one provded by device's kobject and
drop the kref field from struct nvmem_device.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/nvmem/core.c      | 80 ++++++++++++++++++++---------------------------
 drivers/nvmem/internals.h |  1 -
 2 files changed, 34 insertions(+), 47 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index f3024e5a5c5ffae08d34c1155f7e2e31fa8a6fdb..2398d33bdd12eb7d6cac185a49fa6a79da13b1c5 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -535,24 +535,6 @@ static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem)
 
 #endif /* CONFIG_NVMEM_SYSFS */
 
-static void nvmem_release(struct device *dev)
-{
-	struct nvmem_device *nvmem = to_nvmem_device(dev);
-
-	ida_free(&nvmem_ida, nvmem->id);
-	gpiod_put(nvmem->wp_gpio);
-	kfree(nvmem->ops);
-	kfree(nvmem);
-}
-
-static const struct device_type nvmem_provider_type = {
-	.release	= nvmem_release,
-};
-
-static const struct bus_type nvmem_bus_type = {
-	.name		= "nvmem",
-};
-
 static void nvmem_cell_entry_drop(struct nvmem_cell_entry *cell)
 {
 	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_CELL_REMOVE, cell);
@@ -571,6 +553,25 @@ static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem)
 		nvmem_cell_entry_drop(cell);
 }
 
+static void nvmem_release(struct device *dev)
+{
+	struct nvmem_device *nvmem = to_nvmem_device(dev);
+
+	gpiod_put(nvmem->wp_gpio);
+	nvmem_device_remove_all_cells(nvmem);
+	ida_free(&nvmem_ida, nvmem->id);
+	kfree(nvmem->ops);
+	kfree(nvmem);
+}
+
+static const struct device_type nvmem_provider_type = {
+	.release	= nvmem_release,
+};
+
+static const struct bus_type nvmem_bus_type = {
+	.name		= "nvmem",
+};
+
 static void nvmem_cell_entry_add(struct nvmem_cell_entry *cell)
 {
 	scoped_guard(mutex, &nvmem_mutex)
@@ -918,6 +919,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	nvmem->dev.type = &nvmem_provider_type;
 	nvmem->dev.bus = &nvmem_bus_type;
 	nvmem->dev.parent = config->dev;
+	INIT_LIST_HEAD(&nvmem->cells);
 	nvmem->ops = ops;
 
 	device_initialize(&nvmem->dev);
@@ -931,8 +933,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 		goto err_put_device;
 	}
 
-	kref_init(&nvmem->refcnt);
-	INIT_LIST_HEAD(&nvmem->cells);
 	nvmem->fixup_dt_cell_info = config->fixup_dt_cell_info;
 
 	ops->reg_read = config->reg_read;
@@ -993,20 +993,20 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	if (config->cells) {
 		rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
 		if (rval)
-			goto err_remove_cells;
+			goto err_remove_compat;
 	}
 
 	if (config->add_legacy_fixed_of_cells) {
 		rval = nvmem_add_cells_from_legacy_of(nvmem);
 		if (rval)
-			goto err_remove_cells;
+			goto err_remove_compat;
 	}
 
 	dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
 
 	rval = device_add(&nvmem->dev);
 	if (rval)
-		goto err_remove_cells;
+		goto err_remove_compat;
 
 	rval = nvmem_populate_layout(nvmem);
 	if (rval)
@@ -1032,8 +1032,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 #endif
 err_remove_dev:
 	device_del(&nvmem->dev);
-err_remove_cells:
-	nvmem_device_remove_all_cells(nvmem);
+err_remove_compat:
 	nvmem_sysfs_remove_compat(nvmem);
 err_put_device:
 	put_device(&nvmem->dev);
@@ -1042,21 +1041,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 }
 EXPORT_SYMBOL_GPL(nvmem_register);
 
-static void nvmem_device_release(struct kref *kref)
-{
-	struct nvmem_device *nvmem;
-
-	nvmem = container_of(kref, struct nvmem_device, refcnt);
-
-	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
-
-	nvmem_sysfs_remove_compat(nvmem);
-
-	nvmem_device_remove_all_cells(nvmem);
-	nvmem_destroy_layout(nvmem);
-	device_unregister(&nvmem->dev);
-}
-
 /**
  * nvmem_unregister() - Unregister previously registered nvmem device
  *
@@ -1064,8 +1048,15 @@ static void nvmem_device_release(struct kref *kref)
  */
 void nvmem_unregister(struct nvmem_device *nvmem)
 {
-	if (nvmem)
-		kref_put(&nvmem->refcnt, nvmem_device_release);
+	if (!nvmem)
+		return;
+
+	blocking_notifier_call_chain(&nvmem_notifier, NVMEM_REMOVE, nvmem);
+
+	nvmem_sysfs_remove_compat(nvmem);
+	nvmem_destroy_layout(nvmem);
+
+	device_unregister(&nvmem->dev);
 }
 EXPORT_SYMBOL_GPL(nvmem_unregister);
 
@@ -1126,8 +1117,6 @@ static struct nvmem_device *nvmem_device_match(void *data,
 		return ERR_PTR(-EINVAL);
 	}
 
-	kref_get(&nvmem->refcnt);
-
 	return nvmem;
 }
 
@@ -1243,9 +1232,8 @@ EXPORT_SYMBOL_GPL(devm_nvmem_device_put);
  */
 void nvmem_device_put(struct nvmem_device *nvmem)
 {
-	put_device(&nvmem->dev);
 	module_put(nvmem->owner);
-	kref_put(&nvmem->refcnt, nvmem_device_release);
+	put_device(&nvmem->dev);
 }
 EXPORT_SYMBOL_GPL(nvmem_device_put);
 
diff --git a/drivers/nvmem/internals.h b/drivers/nvmem/internals.h
index 4e610deeaa7b3ca41404d52b893b1d27b962e985..2c3645a2727270298139dd7b49b81fa0bda58ad5 100644
--- a/drivers/nvmem/internals.h
+++ b/drivers/nvmem/internals.h
@@ -19,7 +19,6 @@ struct nvmem_device {
 	int			stride;
 	int			word_size;
 	int			id;
-	struct kref		refcnt;
 	size_t			size;
 	bool			read_only;
 	bool			root_only;

-- 
2.47.3