[PATCH v3 05/11] PCI: Use driver_set_override() instead of open-coding

[Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>]

Use a helper for seting driver_override to reduce amount of duplicated
code. Make the driver_override field const char, because it is not
modified by the core and it matches other subsystems.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>
---
 drivers/pci/pci-sysfs.c | 28 ++++------------------------
 include/linux/pci.h     |  7 ++++++-
 2 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 602f0fb0b007..5c42965c32c2 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -567,31 +567,11 @@ static ssize_t driver_override_store(struct device *dev,
 				     const char *buf, size_t count)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
-	char *driver_override, *old, *cp;
-
-	/* We need to keep extra room for a newline */
-	if (count >= (PAGE_SIZE - 1))
-		return -EINVAL;
-
-	driver_override = kstrndup(buf, count, GFP_KERNEL);
-	if (!driver_override)
-		return -ENOMEM;
-
-	cp = strchr(driver_override, '\n');
-	if (cp)
-		*cp = '\0';
-
-	device_lock(dev);
-	old = pdev->driver_override;
-	if (strlen(driver_override)) {
-		pdev->driver_override = driver_override;
-	} else {
-		kfree(driver_override);
-		pdev->driver_override = NULL;
-	}
-	device_unlock(dev);
+	int ret;
 
-	kfree(old);
+	ret = driver_set_override(dev, &pdev->driver_override, buf, count);
+	if (ret)
+		return ret;
 
 	return count;
 }
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8253a5413d7c..5c00a8aebdf9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -516,7 +516,12 @@ struct pci_dev {
 	u16		acs_cap;	/* ACS Capability offset */
 	phys_addr_t	rom;		/* Physical address if not from BAR */
 	size_t		romlen;		/* Length if not from BAR */
-	char		*driver_override; /* Driver name to force a match */
+	/*
+	 * Driver name to force a match.
+	 * Do not set directly, because core frees it.
+	 * Use driver_set_override() to set or clear it.
+	 */
+	const char	*driver_override;
 
 	unsigned long	priv_flags;	/* Private flags for the PCI driver */
 
-- 
2.32.0