linux-kernel - [PATCH 1/2] driver core: Refactor multiple copies of device cleanup

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Date:   Wed, 23 Feb 2022 16:52:56 -0600
From:   Rob Herring <robh@...nel.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] driver core: Refactor multiple copies of device cleanup

There are 3 copies of the same device cleanup code used for probe failure,
testing re-probing, and device unbinding. Changes to this code often miss
at least one of the copies of the code. See commits d0243bbd5dd3 ("drivers
core: Free dma_range_map when driver probe failed") and d8f7a5484f21
("driver core: Free DMA range map when device is released") for example.

Let's refactor the code to its own function.

Signed-off-by: Rob Herring <robh@...nel.org>
---
 drivers/base/dd.c | 46 ++++++++++++++++------------------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index f47cab21430f..19bae32955c1 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -506,6 +506,19 @@ static ssize_t state_synced_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(state_synced);
 
+static void device_unbind_cleanup(struct device *dev)
+{
+	devres_release_all(dev);
+	arch_teardown_dma_ops(dev);
+	kfree(dev->dma_range_map);
+	dev->dma_range_map = NULL;
+	dev->driver = NULL;
+	dev_set_drvdata(dev, NULL);
+	if (dev->pm_domain && dev->pm_domain->dismiss)
+		dev->pm_domain->dismiss(dev);
+	pm_runtime_reinit(dev);
+	dev_pm_set_driver_flags(dev, 0);
+}
 
 static int call_driver_probe(struct device *dev, struct device_driver *drv)
 {
@@ -628,16 +641,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		else if (drv->remove)
 			drv->remove(dev);
 
-		devres_release_all(dev);
-		arch_teardown_dma_ops(dev);
-		kfree(dev->dma_range_map);
-		dev->dma_range_map = NULL;
 		driver_sysfs_remove(dev);
-		dev->driver = NULL;
-		dev_set_drvdata(dev, NULL);
-		if (dev->pm_domain && dev->pm_domain->dismiss)
-			dev->pm_domain->dismiss(dev);
-		pm_runtime_reinit(dev);
+		device_unbind_cleanup(dev);
 
 		goto re_probe;
 	}
@@ -667,16 +672,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
 pinctrl_bind_failed:
 	device_links_no_driver(dev);
-	devres_release_all(dev);
-	arch_teardown_dma_ops(dev);
-	kfree(dev->dma_range_map);
-	dev->dma_range_map = NULL;
-	dev->driver = NULL;
-	dev_set_drvdata(dev, NULL);
-	if (dev->pm_domain && dev->pm_domain->dismiss)
-		dev->pm_domain->dismiss(dev);
-	pm_runtime_reinit(dev);
-	dev_pm_set_driver_flags(dev, 0);
+	device_unbind_cleanup(dev);
 done:
 	return ret;
 }
@@ -1209,17 +1205,7 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 			drv->remove(dev);
 
 		device_links_driver_cleanup(dev);
-
-		devres_release_all(dev);
-		arch_teardown_dma_ops(dev);
-		kfree(dev->dma_range_map);
-		dev->dma_range_map = NULL;
-		dev->driver = NULL;
-		dev_set_drvdata(dev, NULL);
-		if (dev->pm_domain && dev->pm_domain->dismiss)
-			dev->pm_domain->dismiss(dev);
-		pm_runtime_reinit(dev);
-		dev_pm_set_driver_flags(dev, 0);
+		device_unbind_cleanup(dev);
 
 		klist_remove(&dev->p->knode_driver);
 		device_pm_check_callbacks(dev);
-- 
2.32.0