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From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Stuart Yoder <stuyoder@gmail.com>,
        Laurentiu Tudor <laurentiu.tudor@nxp.com>,
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        Sascha Hauer <s.hauer@pengutronix.de>,
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        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
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        Bjorn Helgaas <bhelgaas@google.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
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        Mark Brown <broonie@kernel.org>,
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        linux-arm-kernel@lists.infradead.org, linux-hyperv@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-remoteproc@vger.kernel.org,
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        alsa-devel@alsa-project.org, linux-spi@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Subject: [PATCH v4 05/11] PCI: Use driver_set_override() instead of open-coding
Date:   Sat, 12 Mar 2022 14:28:50 +0100
Message-Id: <20220312132856.65163-6-krzysztof.kozlowski@canonical.com>
In-Reply-To: <20220312132856.65163-1-krzysztof.kozlowski@canonical.com>
References: <20220312132856.65163-1-krzysztof.kozlowski@canonical.com>
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Use a helper to set 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@canonical.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/pci-sysfs.c | 28 ++++------------------------
 include/linux/pci.h     |  6 +++++-
 2 files changed, 9 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 60d423d8f0c4..415491fb85f4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -516,7 +516,11 @@ 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