linux-kernel - [PATCH v4 18/19] fpga: dfl: drop unneeded get_device() and put

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Message-ID: <20241025223714.394533-19-peter.colberg@intel.com>
Date: Fri, 25 Oct 2024 18:37:13 -0400
From: Peter Colberg <peter.colberg@...el.com>
To: Wu Hao <hao.wu@...el.com>,
	Tom Rix <trix@...hat.com>,
	Moritz Fischer <mdf@...nel.org>,
	Xu Yilun <yilun.xu@...el.com>,
	linux-fpga@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Russ Weight <russ.weight@...ux.dev>,
	Marco Pagani <marpagan@...hat.com>,
	Matthew Gerlach <matthew.gerlach@...ux.intel.com>,
	Basheer Ahmed Muddebihal <basheer.ahmed.muddebihal@...ux.intel.com>,
	Peter Colberg <peter.colberg@...el.com>
Subject: [PATCH v4 18/19] fpga: dfl: drop unneeded get_device() and put_device() of feature device

The feature device data was originally stored as platform data, hence
the memory allocation was tied to the lifetime of the feature device.
Now that the feature device data is tied to the lifetime of the DFL PCIe
FPGA device instead, get_device() and put_device() are no longer needed.

Signed-off-by: Peter Colberg <peter.colberg@...el.com>
Reviewed-by: Matthew Gerlach <matthew.gerlach@...ux.intel.com>
Reviewed-by: Basheer Ahmed Muddebihal <basheer.ahmed.muddebihal@...ux.intel.com>
---
Changes since v3:
- New patch extracted from last patch of v3 series.
---
 drivers/fpga/dfl-fme-br.c |  2 --
 drivers/fpga/dfl.c        | 16 +++++-----------
 drivers/fpga/dfl.h        |  5 -----
 3 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/drivers/fpga/dfl-fme-br.c b/drivers/fpga/dfl-fme-br.c
index 5c60a38ec76c..a298a041877b 100644
--- a/drivers/fpga/dfl-fme-br.c
+++ b/drivers/fpga/dfl-fme-br.c
@@ -85,8 +85,6 @@ static void fme_br_remove(struct platform_device *pdev)
 
 	fpga_bridge_unregister(br);
 
-	if (priv->port_fdata)
-		put_device(&priv->port_fdata->dev->dev);
 	if (priv->port_ops)
 		dfl_fpga_port_ops_put(priv->port_ops);
 }
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index a2459b0cbc68..ed38e5ec84b6 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -734,7 +734,6 @@ static void dfl_fpga_cdev_add_port_data(struct dfl_fpga_cdev *cdev,
 {
 	mutex_lock(&cdev->lock);
 	list_add(&fdata->node, &cdev->port_dev_list);
-	get_device(&fdata->dev->dev);
 	mutex_unlock(&cdev->lock);
 }
 
@@ -1636,7 +1635,6 @@ void dfl_fpga_feature_devs_remove(struct dfl_fpga_cdev *cdev)
 		}
 
 		list_del(&fdata->node);
-		put_device(&port_dev->dev);
 	}
 	mutex_unlock(&cdev->lock);
 
@@ -1668,7 +1666,7 @@ __dfl_fpga_cdev_find_port_data(struct dfl_fpga_cdev *cdev, void *data,
 	struct dfl_feature_dev_data *fdata;
 
 	list_for_each_entry(fdata, &cdev->port_dev_list, node) {
-		if (match(fdata, data) && get_device(&fdata->dev->dev))
+		if (match(fdata, data))
 			return fdata;
 	}
 
@@ -1719,19 +1717,17 @@ int dfl_fpga_cdev_release_port(struct dfl_fpga_cdev *cdev, int port_id)
 
 	if (!device_is_registered(&fdata->dev->dev)) {
 		ret = -EBUSY;
-		goto put_dev_exit;
+		goto unlock_exit;
 	}
 
 	mutex_lock(&fdata->lock);
 	ret = dfl_feature_dev_use_begin(fdata, true);
 	mutex_unlock(&fdata->lock);
 	if (ret)
-		goto put_dev_exit;
+		goto unlock_exit;
 
 	platform_device_del(fdata->dev);
 	cdev->released_port_num++;
-put_dev_exit:
-	put_device(&fdata->dev->dev);
 unlock_exit:
 	mutex_unlock(&cdev->lock);
 	return ret;
@@ -1762,20 +1758,18 @@ int dfl_fpga_cdev_assign_port(struct dfl_fpga_cdev *cdev, int port_id)
 
 	if (device_is_registered(&fdata->dev->dev)) {
 		ret = -EBUSY;
-		goto put_dev_exit;
+		goto unlock_exit;
 	}
 
 	ret = platform_device_add(fdata->dev);
 	if (ret)
-		goto put_dev_exit;
+		goto unlock_exit;
 
 	mutex_lock(&fdata->lock);
 	dfl_feature_dev_use_end(fdata);
 	mutex_unlock(&fdata->lock);
 
 	cdev->released_port_num--;
-put_dev_exit:
-	put_device(&fdata->dev->dev);
 unlock_exit:
 	mutex_unlock(&cdev->lock);
 	return ret;
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 2e38c42b3920..95539f1213cb 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -551,11 +551,6 @@ struct dfl_fpga_cdev *
 dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info);
 void dfl_fpga_feature_devs_remove(struct dfl_fpga_cdev *cdev);
 
-/*
- * need to drop the device reference with put_device() after use port platform
- * device returned by __dfl_fpga_cdev_find_port and dfl_fpga_cdev_find_port
- * functions.
- */
 struct dfl_feature_dev_data *
 __dfl_fpga_cdev_find_port_data(struct dfl_fpga_cdev *cdev, void *data,
 			       int (*match)(struct dfl_feature_dev_data *, void *));
-- 
2.47.0