--- /dev/null
+From f72e77c33e4b5657af35125e75bab249256030f3 Mon Sep 17 00:00:00 2001
+From: Douglas Anderson <dianders@chromium.org>
+Date: Tue, 17 Mar 2026 09:01:20 -0700
+Subject: device property: Make modifications of fwnode "flags" thread safe
+
+From: Douglas Anderson <dianders@chromium.org>
+
+commit f72e77c33e4b5657af35125e75bab249256030f3 upstream.
+
+In various places in the kernel, we modify the fwnode "flags" member
+by doing either:
+ fwnode->flags |= SOME_FLAG;
+ fwnode->flags &= ~SOME_FLAG;
+
+This type of modification is not thread-safe. If two threads are both
+mucking with the flags at the same time then one can clobber the
+other.
+
+While flags are often modified while under the "fwnode_link_lock",
+this is not universally true.
+
+Create some accessor functions for setting, clearing, and testing the
+FWNODE flags and move all users to these accessor functions. New
+accessor functions use set_bit() and clear_bit(), which are
+thread-safe.
+
+Cc: stable@vger.kernel.org
+Fixes: c2c724c868c4 ("driver core: Add fw_devlink_parse_fwtree()")
+Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+Acked-by: Mark Brown <broonie@kernel.org>
+Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
+Signed-off-by: Douglas Anderson <dianders@chromium.org>
+Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
+Reviewed-by: Saravana Kannan <saravanak@kernel.org>
+Link: https://patch.msgid.link/20260317090112.v2.1.I0a4d03104ecd5103df3d76f66c8d21b1d15a2e38@changeid
+[ Fix fwnode_clear_flag() argument alignment, restore dropped blank
+ line in fwnode_dev_initialized(), and remove unnecessary parentheses
+ around fwnode_test_flag() calls. - Danilo ]
+Signed-off-by: Danilo Krummrich <dakr@kernel.org>
+(cherry picked from commit f72e77c33e4b5657af35125e75bab249256030f3)
+Signed-off-by: Douglas Anderson <dianders@chromium.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/base/core.c | 24 ++++++++++++------------
+ drivers/bus/imx-weim.c | 2 +-
+ drivers/i2c/i2c-core-of.c | 2 +-
+ drivers/net/phy/mdio_bus.c | 4 ++--
+ drivers/of/base.c | 2 +-
+ drivers/of/dynamic.c | 2 +-
+ drivers/of/platform.c | 2 +-
+ drivers/spi/spi.c | 2 +-
+ include/linux/fwnode.h | 44 +++++++++++++++++++++++++++++++++-----------
+ 9 files changed, 53 insertions(+), 31 deletions(-)
+
+--- a/drivers/base/core.c
++++ b/drivers/base/core.c
+@@ -182,7 +182,7 @@ void fw_devlink_purge_absent_suppliers(s
+ if (fwnode->dev)
+ return;
+
+- fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
++ fwnode_set_flag(fwnode, FWNODE_FLAG_NOT_DEVICE);
+ fwnode_links_purge_consumers(fwnode);
+
+ fwnode_for_each_available_child_node(fwnode, child)
+@@ -228,7 +228,7 @@ static void __fw_devlink_pickup_dangling
+ if (fwnode->dev && fwnode->dev->bus)
+ return;
+
+- fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
++ fwnode_set_flag(fwnode, FWNODE_FLAG_NOT_DEVICE);
+ __fwnode_links_move_consumers(fwnode, new_sup);
+
+ fwnode_for_each_available_child_node(fwnode, child)
+@@ -1013,7 +1013,7 @@ static void device_links_missing_supplie
+ static bool dev_is_best_effort(struct device *dev)
+ {
+ return (fw_devlink_best_effort && dev->can_match) ||
+- (dev->fwnode && (dev->fwnode->flags & FWNODE_FLAG_BEST_EFFORT));
++ (dev->fwnode && fwnode_test_flag(dev->fwnode, FWNODE_FLAG_BEST_EFFORT));
+ }
+
+ static struct fwnode_handle *fwnode_links_check_suppliers(
+@@ -1724,11 +1724,11 @@ bool fw_devlink_is_strict(void)
+
+ static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
+ {
+- if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED)
++ if (fwnode_test_flag(fwnode, FWNODE_FLAG_LINKS_ADDED))
+ return;
+
+ fwnode_call_int_op(fwnode, add_links);
+- fwnode->flags |= FWNODE_FLAG_LINKS_ADDED;
++ fwnode_set_flag(fwnode, FWNODE_FLAG_LINKS_ADDED);
+ }
+
+ static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
+@@ -1888,7 +1888,7 @@ static bool fwnode_init_without_drv(stru
+ struct device *dev;
+ bool ret;
+
+- if (!(fwnode->flags & FWNODE_FLAG_INITIALIZED))
++ if (!fwnode_test_flag(fwnode, FWNODE_FLAG_INITIALIZED))
+ return false;
+
+ dev = get_dev_from_fwnode(fwnode);
+@@ -2004,10 +2004,10 @@ static bool __fw_devlink_relax_cycles(st
+ * We aren't trying to find all cycles. Just a cycle between con and
+ * sup_handle.
+ */
+- if (sup_handle->flags & FWNODE_FLAG_VISITED)
++ if (fwnode_test_flag(sup_handle, FWNODE_FLAG_VISITED))
+ return false;
+
+- sup_handle->flags |= FWNODE_FLAG_VISITED;
++ fwnode_set_flag(sup_handle, FWNODE_FLAG_VISITED);
+
+ /* Termination condition. */
+ if (sup_handle == con_handle) {
+@@ -2077,7 +2077,7 @@ static bool __fw_devlink_relax_cycles(st
+ }
+
+ out:
+- sup_handle->flags &= ~FWNODE_FLAG_VISITED;
++ fwnode_clear_flag(sup_handle, FWNODE_FLAG_VISITED);
+ put_device(sup_dev);
+ put_device(con_dev);
+ put_device(par_dev);
+@@ -2130,7 +2130,7 @@ static int fw_devlink_create_devlink(str
+ * When such a flag is set, we can't create device links where P is the
+ * supplier of C as that would delay the probe of C.
+ */
+- if (sup_handle->flags & FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD &&
++ if (fwnode_test_flag(sup_handle, FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD) &&
+ fwnode_is_ancestor_of(sup_handle, con->fwnode))
+ return -EINVAL;
+
+@@ -2153,7 +2153,7 @@ static int fw_devlink_create_devlink(str
+ else
+ flags = FW_DEVLINK_FLAGS_PERMISSIVE;
+
+- if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE)
++ if (fwnode_test_flag(sup_handle, FWNODE_FLAG_NOT_DEVICE))
+ sup_dev = fwnode_get_next_parent_dev(sup_handle);
+ else
+ sup_dev = get_dev_from_fwnode(sup_handle);
+@@ -2165,7 +2165,7 @@ static int fw_devlink_create_devlink(str
+ * supplier device indefinitely.
+ */
+ if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
+- sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
++ fwnode_test_flag(sup_handle, FWNODE_FLAG_INITIALIZED)) {
+ dev_dbg(con,
+ "Not linking %pfwf - dev might never probe\n",
+ sup_handle);
+--- a/drivers/bus/imx-weim.c
++++ b/drivers/bus/imx-weim.c
+@@ -332,7 +332,7 @@ static int of_weim_notify(struct notifie
+ * fw_devlink doesn't skip adding consumers to this
+ * device.
+ */
+- rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
++ fwnode_clear_flag(&rd->dn->fwnode, FWNODE_FLAG_NOT_DEVICE);
+ if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
+ dev_err(&pdev->dev,
+ "Failed to create child device '%pOF'\n",
+--- a/drivers/i2c/i2c-core-of.c
++++ b/drivers/i2c/i2c-core-of.c
+@@ -182,7 +182,7 @@ static int of_i2c_notify(struct notifier
+ * Clear the flag before adding the device so that fw_devlink
+ * doesn't skip adding consumers to this device.
+ */
+- rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
++ fwnode_clear_flag(&rd->dn->fwnode, FWNODE_FLAG_NOT_DEVICE);
+ client = of_i2c_register_device(adap, rd->dn);
+ if (IS_ERR(client)) {
+ dev_err(&adap->dev, "failed to create client for '%pOF'\n",
+--- a/drivers/net/phy/mdio_bus.c
++++ b/drivers/net/phy/mdio_bus.c
+@@ -705,8 +705,8 @@ int __mdiobus_register(struct mii_bus *b
+ return -EINVAL;
+
+ if (bus->parent && bus->parent->of_node)
+- bus->parent->of_node->fwnode.flags |=
+- FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
++ fwnode_set_flag(&bus->parent->of_node->fwnode,
++ FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD);
+
+ WARN(bus->state != MDIOBUS_ALLOCATED &&
+ bus->state != MDIOBUS_UNREGISTERED,
+--- a/drivers/of/base.c
++++ b/drivers/of/base.c
+@@ -1793,7 +1793,7 @@ void of_alias_scan(void * (*dt_alloc)(u6
+ if (name)
+ of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
+ if (of_stdout)
+- of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
++ fwnode_set_flag(&of_stdout->fwnode, FWNODE_FLAG_BEST_EFFORT);
+ }
+
+ if (!of_aliases)
+--- a/drivers/of/dynamic.c
++++ b/drivers/of/dynamic.c
+@@ -225,7 +225,7 @@ static void __of_attach_node(struct devi
+ np->sibling = np->parent->child;
+ np->parent->child = np;
+ of_node_clear_flag(np, OF_DETACHED);
+- np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
++ fwnode_set_flag(&np->fwnode, FWNODE_FLAG_NOT_DEVICE);
+
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+--- a/drivers/of/platform.c
++++ b/drivers/of/platform.c
+@@ -744,7 +744,7 @@ static int of_platform_notify(struct not
+ * Clear the flag before adding the device so that fw_devlink
+ * doesn't skip adding consumers to this device.
+ */
+- rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
++ fwnode_clear_flag(&rd->dn->fwnode, FWNODE_FLAG_NOT_DEVICE);
+ /* pdev_parent may be NULL when no bus platform device */
+ pdev_parent = of_find_device_by_node(parent);
+ pdev = of_platform_device_create(rd->dn, NULL,
+--- a/drivers/spi/spi.c
++++ b/drivers/spi/spi.c
+@@ -4811,7 +4811,7 @@ static int of_spi_notify(struct notifier
+ * Clear the flag before adding the device so that fw_devlink
+ * doesn't skip adding consumers to this device.
+ */
+- rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
++ fwnode_clear_flag(&rd->dn->fwnode, FWNODE_FLAG_NOT_DEVICE);
+ spi = of_register_spi_device(ctlr, rd->dn);
+ put_device(&ctlr->dev);
+
+--- a/include/linux/fwnode.h
++++ b/include/linux/fwnode.h
+@@ -10,6 +10,7 @@
+ #define _LINUX_FWNODE_H_
+
+ #include <linux/bits.h>
++#include <linux/bitops.h>
+ #include <linux/err.h>
+ #include <linux/list.h>
+ #include <linux/types.h>
+@@ -37,12 +38,12 @@ struct device;
+ * suppliers. Only enforce ordering with suppliers that have
+ * drivers.
+ */
+-#define FWNODE_FLAG_LINKS_ADDED BIT(0)
+-#define FWNODE_FLAG_NOT_DEVICE BIT(1)
+-#define FWNODE_FLAG_INITIALIZED BIT(2)
+-#define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD BIT(3)
+-#define FWNODE_FLAG_BEST_EFFORT BIT(4)
+-#define FWNODE_FLAG_VISITED BIT(5)
++#define FWNODE_FLAG_LINKS_ADDED 0
++#define FWNODE_FLAG_NOT_DEVICE 1
++#define FWNODE_FLAG_INITIALIZED 2
++#define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD 3
++#define FWNODE_FLAG_BEST_EFFORT 4
++#define FWNODE_FLAG_VISITED 5
+
+ struct fwnode_handle {
+ struct fwnode_handle *secondary;
+@@ -52,7 +53,7 @@ struct fwnode_handle {
+ struct device *dev;
+ struct list_head suppliers;
+ struct list_head consumers;
+- u8 flags;
++ unsigned long flags;
+ };
+
+ /*
+@@ -204,16 +205,37 @@ static inline void fwnode_init(struct fw
+ INIT_LIST_HEAD(&fwnode->suppliers);
+ }
+
++static inline void fwnode_set_flag(struct fwnode_handle *fwnode,
++ unsigned int bit)
++{
++ set_bit(bit, &fwnode->flags);
++}
++
++static inline void fwnode_clear_flag(struct fwnode_handle *fwnode,
++ unsigned int bit)
++{
++ clear_bit(bit, &fwnode->flags);
++}
++
++static inline void fwnode_assign_flag(struct fwnode_handle *fwnode,
++ unsigned int bit, bool value)
++{
++ assign_bit(bit, &fwnode->flags, value);
++}
++
++static inline bool fwnode_test_flag(struct fwnode_handle *fwnode,
++ unsigned int bit)
++{
++ return test_bit(bit, &fwnode->flags);
++}
++
+ static inline void fwnode_dev_initialized(struct fwnode_handle *fwnode,
+ bool initialized)
+ {
+ if (IS_ERR_OR_NULL(fwnode))
+ return;
+
+- if (initialized)
+- fwnode->flags |= FWNODE_FLAG_INITIALIZED;
+- else
+- fwnode->flags &= ~FWNODE_FLAG_INITIALIZED;
++ fwnode_assign_flag(fwnode, FWNODE_FLAG_INITIALIZED, initialized);
+ }
+
+ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup,
projects / thirdparty / kernel / stable-queue.git / commitdiff
