linux-kernel - [PATCH v1 1/3] device property: Implement device_is_big

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20231025184259.250588-2-andriy.shevchenko@linux.intel.com>
Date:   Wed, 25 Oct 2023 21:42:57 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-acpi@...r.kernel.org
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Andy Shevchenko <andy@...nel.org>,
        Daniel Scally <djrscally@...il.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Rob Herring <robh+dt@...nel.org>
Subject: [PATCH v1 1/3] device property: Implement device_is_big_endian()

Some users want to use the struct device pointer to see if the
device is big endian in terms of Open Firmware specifications,
i.e. if it has a "big-endian" property, or if the kernel was
compiled for BE *and* the device has a "native-endian" property.

Provide inline helper for the users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 include/linux/property.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/include/linux/property.h b/include/linux/property.h
index 2b8f07fc68a9..d1400a477b0a 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -80,12 +80,38 @@ int fwnode_property_match_string(const struct fwnode_handle *fwnode,
 
 bool fwnode_device_is_available(const struct fwnode_handle *fwnode);
 
+static inline bool fwnode_device_is_big_endian(const struct fwnode_handle *fwnode)
+{
+	if (fwnode_property_present(fwnode, "big-endian"))
+		return true;
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+	    fwnode_property_present(fwnode, "native-endian"))
+		return true;
+	return false;
+}
+
 static inline
 bool fwnode_device_is_compatible(const struct fwnode_handle *fwnode, const char *compat)
 {
 	return fwnode_property_match_string(fwnode, "compatible", compat) >= 0;
 }
 
+/**
+ * device_is_big_endian - check if a device has BE registers
+ * @dev: Pointer to the struct device
+ *
+ * Returns: true if the device has a "big-endian" property, or if the kernel
+ * was compiled for BE *and* the device has a "native-endian" property.
+ * Returns false otherwise.
+ *
+ * Callers would nominally use ioread32be/iowrite32be if
+ * device_is_big_endian() == true, or readl/writel otherwise.
+ */
+static inline bool device_is_big_endian(const struct device *dev)
+{
+	return fwnode_device_is_big_endian(dev_fwnode(dev));
+}
+
 /**
  * device_is_compatible - match 'compatible' property of the device with a given string
  * @dev: Pointer to the struct device
-- 
2.40.0.1.gaa8946217a0b